HK1210543B - System and method for automatically correcting for rotational misalignment of wafers on film frames - Google Patents

Abstract

Automatically correcting for rotational misalignment of a wafer improperly mounted on a film frame includes capturing an image of portions of the wafer using an image capture device, prior to initiation of a wafer inspection procedure by an inspection system; digitally determining a rotational misalignment angle and a rotational misalignment direction of the wafer relative to the film frame and/or a set of reference axes of a field of view of the image capture device; and correcting for the rotational misalignment of the wafer by way of a film frame handling apparatus separate from the inspection system, which is configured for rotating the film frame across the rotational misalignment angle in a direction opposite to the rotational misalignment direction. Such film frame rotation can occur prior to placement of the film frame on the wafer table, without decreasing film frame handling throughput or inspection process throughput.

Description

System and method for automatically correcting rotational misalignment of wafers on a film frame

Technical Field

Aspects of the present disclosure relate to a system and method for automatically detecting and correcting or compensating for rotational misalignment of wafers carried by a film frame to facilitate accurate, high throughput inspection processes.

Background

Semiconductor wafer processing operations include performing various types of processing steps or processing sequences on a semiconductor wafer on which a plurality of dies (e.g., a large or very large number of dies) are present. The geometry, line width, or characteristic dimensions of devices, circuits, or structures on each die are typically very small (e.g., on the micron, submicron, or nanometer scale). Any given die includes a large number of integrated circuits or circuit structures that are fabricated, processed, and/or patterned layer-by-layer, e.g., by means of processing steps performed on a wafer placed on a flat wafer surface, such that the die carried by the wafer are collectively subjected to the processing steps.

Various semiconductor device processing operations involve multiple handling systems that perform wafer or film frame handling operations involving securely and selectively transporting a wafer or wafer mounted on a film frame (hereinafter referred to simply as a "film frame") from one location, place, or destination to another location, place, or destination and/or holding a wafer or film frame in a particular location during a wafer or film frame processing operation. For example, before starting the optical inspection process, the handling system must take a wafer or film frame from a wafer or film frame source, such as a wafer cassette, and transfer the wafer or film frame to the wafer table. The wafer table must hold the wafer or film frame firmly to its surface before the inspection process is started and must release the wafer or film frame from its surface after the inspection process is completed. Once the inspection process is complete, the handling system must retrieve the wafer or film frame from the wafer table and transfer the wafer or film frame to the next destination, such as a wafer or film frame cassette or another processing system.

Various types of wafer handling systems and film frame handling systems are known in the art. Such handling systems can include one or more mechanical or robotic arms configured to perform wafer handling operations (which involve transferring wafers to and retrieving wafers from a wafer table); or to perform film frame handling operations (which involve transferring the film frame to the wafer table and retrieving the film frame from the wafer table). Each robotic arm includes an associated end effector configured to acquire, pick, hold, transfer and release a wafer or film frame by means of application and discontinuation of vacuum forces to portions of the wafer or film frame in a manner understood by those skilled in the art.

The wafer table itself can be considered or defined as a handling system that must reliably, securely, and selectively position and hold a wafer or film frame on the wafer table surface while moving the wafer or film frame relative to elements of the processing system (e.g., corresponding to one or more image capture devices and one or more light sources of an optical inspection system). The structure of the wafer table can significantly impact whether the inspection system can achieve a high average inspection throughput as described in more detail below. In addition, the structure of the wafer table greatly affects whether the optical inspection process can reliably produce accurate inspection results, in relation to the physical properties of the wafer and the physical properties of the film frame.

With respect to the generation of accurate inspection results, the wafer or film frame must be securely held on the wafer table during the optical inspection process. Furthermore, the wafer table must arrange and maintain the upper or top surface of the wafer or film frame in the same inspection plane so that all or as much of the surface area of the wafer die as possible are located together on the same plane with minimal or negligible deviation. More specifically, proper or accurate optical inspection of the die at very high magnification requires that the wafer table be very flat, preferably with an error margin in planarity of the wafer table that is less than 1/3 of the depth of field of the image capture device. If the depth of field of the image capture device is, for example, 20 μm, the corresponding wafer table planarity error cannot exceed 6 μm.

This planarity requirement becomes critical in order to handle very small (e.g., 0.5 x 0.5mm or less) and/or thick (50 μm or less-e.g., carried by very thin and/or flexible wafers or substrates) die. For very thin wafers, it is important that the wafer table be ultra-flat, otherwise one or more dies on the wafer or film frame are easily positioned out of depth of field. Those skilled in the art will appreciate that the smaller the die, the higher the magnification required, and thus the narrower the band of depth of field in which the inspection plane is located.

With planarity as outlined above, a wafer placed on the wafer table will lie flat on the wafer table surface, the wafer squeezing out almost all the air underneath it. The difference in atmospheric pressure between the top and bottom surfaces of the wafer when the wafer is disposed on the wafer table results in a large force being exerted on the top surface of the wafer due to the atmospheric pressure, while holding the wafer strongly or rather strongly on the wafer table. Since the pressure is a function of the surface area, the larger the size of the wafer, the greater the force exerted downward on the wafer. This is commonly referred to as "intrinsic suction" or "natural suction" on the wafer. The flatter the wafer table surface, the stronger the natural suction force, up to the limit defined by the finite surface of the wafer. However, the strength of such suction depends on the flatness of the wafer stage. Some wafer tables are not as flat and may have other grooves or holes on their surface, resulting in reduced suction. Despite such natural suction, it is ensured that the wafer remains as flat as possible and does not move during inspection because the wafer table will repeatedly accelerate over short distances during inspection of each die, and a large vacuum force is typically applied by the wafer table to the wafer table surface to reach the underside of the wafer.

Different types of wafer table structures have been developed in an attempt to securely hold a wafer or film frame during a wafer or film frame inspection operation and to reliably hold a maximum number of dies on the same plane during the inspection operation. However, none of the designs would allow a wafer handling system to handle wafers and cut wafers mounted on film frames without one or more of the problems described below. Each type of existing design and its associated problems will be briefly described.

Several types of wafer chucks have been or are currently being used. In the past, wafers were small (e.g., 4, 6, or 8 inches) and significantly thicker (particularly compared to their overall surface area, e.g., based on wafer thickness normalized by wafer surface area), resulting in larger per die sizes. Current wafer sizes are typically 12 or 16 inches and the thickness of these processed wafers decreases with increasing size and die size (e.g., 0.5-1.0 square millimeters), respectively (e.g., typically, for a 12 inch wafer, the thickness is 0.70-1.0 mm before thinning/backgrinding/backpolishing and 50-150 μm after thinning/backpolishing). It can be expected that the standard wafer size increases further over time. Furthermore, it can be expected that wafers to be processed are becoming thinner each year in response to the increasing demand and demand by electronic device and mobile phone manufacturers to embed thinner die/thinner components into thin electronic devices (e.g., flat panel televisions, mobile phones, notebook computers, tablet computers, etc.). These factors, which lead to increasing deficiencies in current designs of wafer tables for handling wafers and film frames, are described below.

Historically, even today, many wafer clamps are made of metal, such as steel. Such metal wafer clamps embed a network of trenches (typically circular trenches) that intersect with trenches that radiate linearly from a central location. By such grooves, vacuum forces can be applied to the underside of the wafer intersecting the wafer table surface, thereby facilitating secure retention of the wafer relative to the wafer table surface. In many wafer table designs, such grooves are arranged in concentric circles of increasing size. Depending on the size of the wafer, when the wafer is placed on the wafer table surface, the wafer will cover the one or more grooves. The vacuum can be activated through the trenches covered by the wafer to hold the wafer down during processing operations (e.g., wafer inspection operations). After inspection, the vacuum is deactivated and the ejector pins are employed to lift the wafer off the wafer table surface so that the wafer can be accessed or removed by the end effector. Because there are linear grooves radiating from the center of the metal wafer table surface, once the vacuum is deactivated, the residual suction force associated with the application of the vacuum force to the underside of the wafer quickly disappears. Thicker wafers are more suitable for application of a significant force applied through the pop-pins to lift the wafer (and resist any residual suction if present) without breaking.

As noted above, wafers are increasingly being manufactured today that are thinner or thinner than before (e.g., current wafer thicknesses can be as thin as 50 μm), and the size of each die thereon is also increasingly shrinking from the past (e.g., 0.5mm square). Advances in technology have resulted in smaller die sizes and thinner dies, which have resulted in problems handling wafers with existing wafer table designs. Typically, a back-ground/thinned or diced wafer (hereinafter "diced wafer") having very small-sized and/or very thin dies is mounted on a film frame for processing. Conventional metal wafer tables are not suitable for use with a film frame to which the diced wafers are mounted for a number of reasons.

It is noted that inspection of a die involves very high magnifications, the higher the magnification, the narrower the acceptable depth of field, range, variation, or tolerance that will be used for accurate inspection. Die that are not on the same plane may not be within the depth of field of the image capture device. As described above, the depth of field of modern image capture devices for wafer inspection typically ranges from 20-70 μm or less depending on the magnification. The presence of grooves on the wafer table surface can be problematic, particularly during inspection of diced wafers (small die size) mounted on a film frame on such systems.

The presence of the grooves results in the diced wafer with smaller die size not being properly or uniformly placed on the wafer table surface. In particular, in areas where there are trenches (and can be many trenches), the diaphragms of the diaphragm holders can hang slightly into the trenches, resulting in a lack of global or uniform planarity across the wafer surface across all dies, which is important for optical inspection operations. The lack of planarity is more pronounced for small or very small die of the diced wafer. Furthermore, the presence of the grooves enables the dies to be placed at an angle with respect to the same die inspection plane, or to fall into and lie on one or more different and lower planes. In addition, light falling onto the tilted die in the trench will reflect from the image capture device such that the image capture corresponding to the tilted die will not include or convey the precise details and/or features of one or more regions of interest on the die. This will adversely affect the quality of the images captured during the examination, which can lead to inaccurate examination results.

A number of previous approaches have attempted to address the foregoing problems. For example, in one approach, the metal wafer table support comprises a network of grooves. A flat metal mesa is placed on top of the trench network. The metal plate includes many small or very small vacuum holes that allow a vacuum to be applied to the wafer or diced wafer through the holes. Depending on the size of the wafer under consideration, an appropriate pattern or number of corresponding trenches will be activated. While multiple small or very small vacuum holes can increase the likelihood of holding the die together on the same inspection plane, the overall die planarity issue is still not effectively or completely eliminated due to continued technological developments that result in smaller and smaller die sizes and smaller die thicknesses. Such designs also include sets of triplets of pop-pins corresponding to different wafer sizes, i.e., sets of triplets of pop-pins corresponding to different sets of standard wafer sizes that the wafer table is capable of carrying. Multiple holes for the pop-pins can also be present and, for reasons similar to those described above, the overall die planarity issue can be more severe when inspecting die carried on the film frame.

Some manufacturers use a wafer table conversion kit in which a grooved metal wafer table is used to handle the entire wafer and a metal wafer table cover with many very small openings is used to handle the film frame. Unfortunately, the conversion kit requires inspection system down time because the conversion from one type of wafer table to another and the wafer table calibration after conversion is time consuming and needs to be done manually. Such downtime can have a detrimental effect on average system throughput (e.g., overall or average throughput associated with sequential or co-considering wafer and film frame inspection operations), and thus it is undesirable to require an inspection system for a wafer table conversion kit.

Other wafer table designs, such as that described in U.S. patent 6513796, involve a wafer pedestal that allows a different central wafer table insert depending on whether the wafer is currently being processed or the film frame. For wafer inspection, the insert is typically a metal plate with an annular ring having vacuum holes for initiating a vacuum. For membrane frame inspection, the interposer is a metal plate with many micro holes for vacuum activation, which still leads to the overall die non-planarity problem as described above.

Another wafer table design, such as U.S. patent application publication 2007/0063453, uses a wafer table having a plate-type insert constructed of a porous material in which annular rings made of a thin film material are used to define the various zones. In general, such wafer table designs are complex in construction and involve specialized and complex processes, so their manufacture is difficult, time consuming, or costly. In addition, such a design enables the use of a metallic annular ring to achieve control of the area vacuum force on the wafer table surface as a function of wafer size. The metal annular ring can require undesirably long planarization times or damage the polishing apparatus used to polish the wafer table surface while planarizing the wafer table surface. In addition, the metal ring can cause non-planarity problems due to different material polishing characteristics of the wafer table surface, and therefore the metal ring is not suitable for modern optical inspection processes (e.g., optical inspection processes particularly involving post-dicing wafers mounted on a film frame).

Unfortunately, past wafer table designs (a) make the structure unnecessarily complex due to insufficient wafer table surface flatness uniformity that arises in view of the technological developments that continue to result in smaller and smaller wafer die sizes and/or tapering of wafer thicknesses; (b) it is difficult, expensive or time consuming to manufacture; and/or (c) not suitable for various types of wafer processing operations (e.g., die inspection operations, particularly when the die are carried by a film frame). There is clearly a need for a wafer table structure and associated wafer table fabrication techniques that will enable a wafer table to handle both wafers and cut wafers that overcomes one or more of the aforementioned problems or deficiencies.

In addition to the above-described aspects of wafer table design that can affect the accuracy and average throughput of wafer and film frame inspections, there can be a variety of other types of wafer or film frame handling problems that can adversely affect wafer or film frame inspection operations. Such problems and prior art solutions to these problems are described in detail below.

Wafer-wafer table retention failure due to wafer non-planarity

One type of wafer handling problem is due to wafer non-planarity or warpage. This problem arises from a number of factors, including (a) the increasing size of wafers manufactured; (b) the thickness of the wafer to be held is smaller and smaller; and (c) the manner in which the wafers are handled or stored before and after processing. The wafer is held at its edge within the cassette before and after processing, such as optical inspection. Given the increase in diameter and thickness of the wafer and the manner in which the wafer is held in the cassette, sagging of the wafer near its center or wafer warpage is common. Furthermore, during the back thinning process, which thins the wafer to the required dimensions, the thinning process can cause the wafer to have reverse warpage, although this problem is less common.

When a non-planar wafer is placed on the wafer table, the vacuum force applied through the wafer table surface, which is intended to hold the entire ground surface of the wafer firmly against the wafer table surface, will only weakly hold a portion of the bottom wafer surface. Since other portions of the wafer will be above the wafer table surface and the vacuum applied through the wafer table will leak and any residual vacuum force will be very weak. In such a case, the wafer would not be held firmly down, and furthermore, such warped wafers 10 are often not capable of reliable inspection or testing.

Prior art techniques aimed at ensuring that the entire surface area of the wafer remains securely on the wafer table surface involve automatically stopping inspection system operation when insufficient vacuum maintenance force (or vacuum leakage below a minimum vacuum maintenance threshold) is detected, until manual intervention by an inspection system operator or user. To address this problem, the inspection system operator manually presses the wafer against the wafer table surface until the vacuum force applied by the wafer table surface acts on the entire surface area of the wafer and securely holds the wafer against the wafer table surface. Such automatic stopping of the inspection system operation due to insufficient vacuum maintenance of the wafer on the wafer table surface can only be resumed after user intervention to manually correct the problem. Such downtime adversely affects system throughput.

Unpredictable/uncontrollable lateral wafer displacement after vacuum force cessation

Typically, to inspect a wafer, the following steps are taken to place the wafer on the wafer table: (a) taking the wafer out of the wafer cassette and sending to a wafer (pre) aligner; (b) the wafer aligner properly adjusts the orientation of the wafer for inspection; (c) after the wafer is aligned, the end effector transfers the wafer to a preset position, and the center of the wafer is aligned with the center of the wafer platform at the preset position; (d) activating the pop-up pin to receive the wafer; (e) the end effector lowers the wafer onto the eject pin prior to retraction; and (f) ejecting the pins and then lowering the wafer to the wafer table for inspection while applying a vacuum to hold the wafer down for inspection.

When the inspection is completed, (a) the vacuum is released; (b) lifting the wafer using the pop-up pin; (c) the end effector slides under the wafer and lifts the wafer; and (d) the end effector returns the inspected wafer to the wafer box and places the wafer into the wafer box.

It is important to note that in order for the effector to be able to place a wafer into a cassette, it is important that the wafer remains in a predetermined position and does not change its position relative to the end effector since it was placed on the wafer table. This means that the wafer must not move from the time it was placed on the stage. If the wafer is significantly or severely dislodged from its position relative to the end effector, the following risks exist: the wafers can fall off during transport or may be damaged when the end effector attempts to push the out-of-position wafer into the cassette. To prevent these accidents, when the wafer is finally picked up by the effector at the end of the inspection, the wafer should be in the same position with respect to the end effector as when the wafer was placed on the wafer table before the start of the inspection. To hold the wafer in its position when placed by the end effector, a vacuum is initiated through the grooves in addition to the natural suction created when the entire or a portion of the wafer lies flat on the wafer table.

In certain instances, after application of the vacuum force or negative pressure to the underside of the wafer ceases, the wafer can slide laterally along the wafer table surface as a result of the next event or process step. Unpredictable lateral movement of the wafer causes the wafer to move or translate to a position that is different from the position at which the wafer was originally placed on the wafer table before or at the beginning of inspection (i.e., the wafer slides laterally away from the reference wafer table position associated with the effector placing and acquiring the wafer). Therefore, when the actuator picks up a wafer where unreliable or unpredictable misalignments have occurred due to such lateral movement, there is a risk that: the wafer may be dropped or damaged when the actuator attempts to load the out-of-position wafer 10 back into the cassette.

Prior techniques for managing unwanted lateral wafer displacement relative to the wafer table after vacuum force ceases involve manual intervention, which again results in interruption of inspection or testing system operation, adversely affecting production throughput.

Wafer-film frame rotational misalignment

At a particular stage of wafer fabrication, the wafer is mounted on a film frame. For example, when a wafer is to be diced, the wafer is typically mounted on a film frame. After dicing, the diced wafer on the film frame is further inspected for cosmetic and/or other types of defects. Fig. 1A is a view of a wafer 10 mounted on a film frame 30, the film frame 30 carrying the wafer 10 by means of a thin layer of material or film 32 in a manner readily understood by a person skilled in the art, wherein the thin layer of material or film 32 generally comprises an adhesive side to which the wafer 10 is mounted. The wafer 10 includes a plurality of dies 12, the dies 12 being separated or scribed from each other by horizontal grid lines 6 and vertical grid lines 8 that become apparent or created during fabrication. Such horizontal and vertical grid lines 6, 8 correspond to or depict the horizontal and vertical sides 11, 16, respectively, of the die. Those skilled in the art will appreciate that the wafer 10 typically includes at least one reference feature 11 (e.g., a notch or straight portion or "flat" portion on a circular outer periphery) to facilitate wafer alignment operations. Those skilled in the art will further appreciate that the film frame 30 includes a plurality of registration or alignment features 34a-b to facilitate the film frame alignment operation. The film frame 30 can also include a number of other reference features, such as "flats" 35 a-d.

With respect to optical inspection, the dies 12 on the wafer 10 are automatically inspected or vetted according to inspection criteria for identifying appearance or other (e.g., structural) defects on the dies 12. Dies 12 that meet inspection criteria and dies that do not can be tracked or sorted according to "pass" or "fail" designation, respectively. Dies 12 that successfully meet all inspection criteria are suitable for further processing or integration into an integrated circuit package, while dies 12 that fail to meet all inspection criteria can (a) be discarded; (b) performing an analysis to determine a cause of the failure and prevent future failures; or (c) reworking/reprocessing under certain circumstances.

Optical inspection involves directing illumination to individual dies 12 or arrays of dies 12; capturing illumination reflected from the die 12 using an image capture device and generating image data corresponding to the die 12; and performing image processing operations on the image data to determine whether one or more types of defects are present on the die 12. Optical inspection is typically performed "en route" while the wafer 10 is in motion, so that the dies 12 carried by the wafer 10 are continuously moved relative to the image capture device during the image capture operation.

Inspecting the entire wafer 10 requires generating inspection results (e.g., pass/fail results) corresponding to each die 12 on the wafer 10. Before inspection results corresponding to any given die 12 can be generated, the entire surface area of the die 12 must first be completely captured. In other words, a complete inspection of any given die 12 requires that the entire surface area of the die must first be captured by an image capture device and that image data corresponding to the entire surface area of each die 12 must be generated and processed. If image data corresponding to the entire surface area of the die is not generated, image processing operations corresponding to the die 12 cannot be completed, and inspection results cannot be generated unless a set of images covering the entire surface area of the die 12 is captured or an "entire die image" is captured. Therefore, if image data corresponding to the entire surface area of the die 12 or image data of the entire die has not been generated, generation of the inspection result of the die 12 is unnecessarily delayed, which has an adverse effect on inspection processing throughput.

The greater the number of image capture operations required to fully capture the entire die image for image processing, the lower the throughput of the inspection. This may be deduced that in order to maximize inspection processing throughput, it should be preferable to capture the entire surface area of each die with as few images as possible.

Errors in the orientation of the wafer 10 can occur when the wafer 10 is mounted on the film frame 30. In general, errors in wafer mounting are related to the wafer flats or notches 11 not being properly aligned with a given film frame reference feature (e.g., film frame flat 35 a). Fig. 1B is a schematic view of a wafer 10 rotationally misaligned relative to a film frame 30 carrying the wafer 10. It can be clearly seen that the rotational orientation of the wafer 10 relative to its film frame 30 shown in fig. 1B differs significantly from the rotational orientation of the wafer 10 relative to its film frame 30 shown in fig. 1A. More specifically, it can be seen from fig. 1B that, with respect to a horizontal reference axis 36 and/or a vertical axis 38 defined parallel and perpendicular to the first film frame flat portion 35a, respectively, a pair of reference horizontal and vertical wafer gridlines 6, 8 are rotated, angularly offset, or misaligned by an angle θ as compared to the wafer 10 shown in fig. 1A.

In other words, for the wafer 10 shown in fig. 1A, the angle θ, which indicates how much the wafer gridlines 6, 8 rotate away from the reference axes 36, 38 having a predetermined orientation relative to the first film frame flat 35a, is almost zero. For the wafer 10 shown in fig. 1B, the wafer is misaligned with respect to the film frame by a non-zero angle θ. As wafer sizes increase, particularly for larger wafer sizes (e.g., 12 inches or more), rotational misalignment of the mounted wafer 10 relative to the film frame 30 often creates problems during inspection of the wafer 10 mounted on the film frame 30, as will be described in further detail below.

During the capture of a given image of the die 12, the image capture device of the inspection system can capture illumination reflected only from those portions of the surface area of the die that are within the field of view (FOV) of the image capture device. The portion of the die surface area outside the FOV of the image capture device cannot be captured as part of this image and must be captured as part of another image. As described above, maximizing inspection process throughput requires capturing the entire surface area of each die 12 on the wafer 10 with as few images as possible. When multiple image capture operations are required to generate image data corresponding to the entire surface area of the die, the generation of inspection results for the die 12 is delayed, which has an adverse effect on throughput. Therefore, each die 12 on the wafer 10 must be properly aligned with respect to the image capture device FOV in order to minimize the number of image capture operations required to generate the entire die image data for all of the dies 12 on the wafer 10 in order to maximize inspection processing throughput.

Proper alignment of the die 12 relative to the image capture device FOV can be defined as a condition in which any rotational or angular misalignment of the die 12 relative to the image capture device FOV is small enough, subtle, or negligible such that the entire surface area of the die will fall within the FOV. Fig. 2A is a schematic illustration of proper positioning or alignment with respect to an image capture device field of view (FOV) 50. As clearly shown in fig. 2A, with proper die alignment relative to the FOV50, the horizontal edge or side 14 of the die 12 is aligned substantially parallel to the FOV horizontal axis X_IAnd the vertical edge or side 16 of the die 12 is aligned substantially parallel to the FOV vertical axis Y_I. Thus, the entire surface area of such a die 12 is within the FOV50, and the entire surface area of the die 12 can be captured by an image capture device in a single image capture event, operation, or "shot.

Fig. 2B is a schematic illustration of a die 12 improperly positioned or misaligned relative to the image capture device FOV 50. FIG. 2B clearly shows that the horizontal and vertical sides of the dies 14, 16 are respectively from the FOV horizontal axis X_IAnd FOV vertical axis Y_IRotated or angularly offset and a portion of the surface area of the dieOutside the FOV 50. Due to such misalignment of the die 12 relative to the FOV50, generating image data corresponding to the entire surface area of the die 12 requires capturing multiple images of different portions of the die 12, resulting in a reduction in inspection processing throughput. More particularly, as shown in fig. 2C, to capture the entire surface area of such rotationally misaligned die 12, up to four images may need to be captured, depending on the degree of misalignment of the die relative to the FOV.

When handling the film frame, a mechanical film frame registration process must typically be performed. Typically, the film frame registration process occurs while the film frame is placed on the wafer holding stage. In some systems, such as singapore patent application No. 201103524-3 entitled "System and Method for Handling and Aligning components such as wafers and Film Frames," filed on 12.5.2011, mechanical Film frame registration can be performed prior to placing the Film frame on the wafer table, e.g., an end effector carrying the Film frame engages a set of Film frame alignment features 34a-b with Film frame registration elements or structures prior to placing the Film frame on the wafer table.

The mechanical film frame registration process involves a certain amount of handling time. However, the film frame registration process generally ensures that the film frame 30 is properly aligned or registered with respect to the image capture device FOV. However, this assumes that the wafer is properly mounted on the film frame for the first time, but this is not always the case. In the case of wafers mounted on a film frame with rotational misalignment, problems and delays in inspection can result, which adversely affect throughput, as will be described in more detail below.

The film frame registration process is performed by means of mating engagement between film frame registration features 34a-b and one or more film frame registration elements conventionally carried by the wafer table assembly. After the film frame 30 has been registered, the die 12 on the wafer 10 mounted on the film frame 30 are expected to be properly aligned with respect to the image capture device FOV. However, if there is a slight or minimal amount of rotation or angular misalignment of the wafer 10 mounted to the film frame 30, the die 12 will not be properly aligned with respect to the image capture device FOV. Thus, this illustrates that the extent of any rotational misalignment of the wafer 10 during mounting of the wafer 10 to the film frame 30 can adversely affect the number of images required to capture the entire surface area of each die 12 on the wafer 12, and thus the extent of any rotational misalignment of the wafer 10 relative to the film frame 30 can adversely affect inspection throughput.

Proper alignment of the wafer 10 relative to its film frame 30 ensures proper alignment of the die 12 relative to the image capture device FOV 50. Proper alignment of the wafer 10 relative to its film frame 30 can be defined as the case where one or more wafer gridlines 6, 8 have a standard predetermined alignment relative to one or more thin film structure features, such as film frame flats 35a-d, and/or the image capture device FOV, such that each die 12 is positioned relative to the image capture device FOV in the manner shown in FIG. 2A (i.e., the horizontal and vertical sides 14, 16 and FOV horizontal and vertical axes X of each die and FOV)_IAnd Y_IAligned). Such alignment of the wafer 10 relative to the film frame 30 minimizes the number of image capture operations required to capture the complete surface area of each die, thereby maximizing inspection processing throughput.

To further illustrate, fig. 2D is a schematic view of the wafer 10 properly mounted on the film frame 30 and aligned relative to the film frame 30 and the inspection process wafer travel path along which the image capture device captures images of the entire surface area of each die 12 within successive rows of dies 12 on the wafer 10. Two representative rows of dies 12 are shown in FIG. 2D, namely "A" row dies 12 and "B" row dies. Because this wafer 10 is properly aligned relative to its film frame 30, the entire surface area of each die 12 within row "a" can be captured in a single corresponding image during the inspection process (e.g., while the wafer 10 is in motion, or "en route"). Immediately after capturing the image corresponding to row "a" dies, the wafer 10 is positioned so that the surface area of row "B" dies 12 closest to the last considered row "a" dies 12 can be captured by the image capture device, and the inspection proceeds in the opposite direction of travel. Thus, this inspection travel path is "meandering". Again, since the wafer 10 is properly aligned relative to its film frame 30, the entire surface area of each die 12 within a "B" row can be captured in a single corresponding image during the inspection process. Inspection of the entire wafer 10 in this manner results in maximum inspection process throughput when the wafer 10 is properly aligned relative to its film frame 30.

Fig. 2E is a schematic view of the wafer 10 rotationally misaligned relative to the film frame 30 carrying the wafer and an inspection process wafer travel path along which the image capture device captures a portion of less than the entire surface area of each die 12 within a successive row of die 12 on the wafer 10 during any single image capture event. As a result of such rotational misalignment of the wafer relative to the film frame during the optical inspection process, the horizontal and vertical sides 14, 16 of the die 12 carried by the wafer 10 will be aligned from the FOV horizontal and vertical axes X, respectively, even when the film frame 30 itself is properly aligned relative to the image capture device_IAnd Y_IAnd rotating to deviate. Thus, the entire surface area of a given die 12 may not fall within the image capture device FOV50, and multiple single images would be required to capture the entire surface area of the given die. Since the inspection results cannot be generated for the die 12 until the multiple images have captured the entire surface area of the die, the generation of the inspection results corresponding to the die 12 is undesirably delayed.

When the inspection involves a set of dies 12, then similar considerations as described above apply. Fig. 2F is a schematic diagram of the die array 18 in which the overall surface area of all of the dies 12 in the die array 18 is less than the image capture device FOV50, and since the horizontal and vertical sides 14, 16, respectively, of each die 12 in the die array 18 are substantially parallel to the FOV horizontal axis X_IAnd FOV vertical axis Y_ISuch that the array of dies 18 is properly aligned with respect to the FOV. Thus, the entire die array 18 can be captured by the image capture device as a single image,thereby maximizing inspection processing throughput. FIG. 2G is a schematic diagram of the die array 18 for which the horizontal and vertical sides 14, 16 of the die 12 within the die array 18 are not aligned with respect to the FOV horizontal and vertical axes X_IAnd Y_IAnd (4) proper alignment. Thus, some portion of the die array 18 is outside the FOV 50. As a result, multiple images of the die array 18 must be captured before inspection results can be generated for the die array 18, thereby degrading throughput.

Furthermore, considerations similar to those described above also apply to inspection involving a single (e.g., large) die 12 having a surface area greater than the FOV50 when properly aligned relative to the image capture device FOV 50. Fig. 2H is a schematic illustration of a single die 12 having a surface area greater than the FOV50 of the image capture device. This die 12 is also properly aligned relative to the FOV50 because the horizontal and vertical sides 14, 16 of the die are substantially parallel to the FOV horizontal and vertical axes X, respectively_IAnd Y_I. As a result, the entire surface area of the die 12 can be captured with a minimum number of image capture operations. In this example, the image capture device must capture a total of 9 images to inspect the entire surface area of the die 12 by: different portions of the surface area of the die are successively positioned relative to the image capture device and an image of each portion of the surface area of the die that falls within the image capture device FOV50 is captured during each such relative positioning.

FIG. 2I is a schematic view of a single die 12 such as shown in FIG. 2H, the die 12 being to be fully inspected by capturing 9 images under proper FOV alignment conditions, but for the die 12 the horizontal and vertical die sides are X-axis relative to the FOV horizontal and vertical axes_IAnd Y_IResulting in portions of the die 12 that remain outside the image capture device FOV50 even though 9 images have been captured.

The prior art systems and methods rely on either manual intervention or a rotatable wafer table for compensating or correcting for rotational misalignment between the wafer 10 and the film frame 30. As before, manual intervention can adversely affect system throughput. With respect to the rotatable wafer table, such wafer table is configured to selectively provide a rotational displacement of an amount sufficient to compensate or substantially compensate for rotational misalignment of the wafer relative to the film frame. The magnitude of the misalignment between the wafer 10 and the film frame 30 can span a large number of degrees, e.g., 10-15 degrees or more, in either the positive or negative direction. Unfortunately, a wafer table configured to provide such rotation is overly complex and therefore expensive (e.g., prohibitively expensive) from a mechanical standpoint. Furthermore, the additional structural complexity of providing such a wafer table assembly with rotational wafer table displacement can make it more difficult to always maintain the wafer table surface in a single plane perpendicular to the optical axis of the image capture device while performing an inspection.

Accordingly, there is a need for a wafer and film frame handling system that provides a single wafer table structure for handling wafers and film frames, and that is capable of automatically overcoming at least some of the aforementioned problems due to wafer warpage, unpredictable lateral wafer motion, and rotational misalignment of the wafer relative to the film frame, as described above, and of enhancing or maximizing inspection process throughput.

Disclosure of Invention

According to one aspect of the present disclosure, a system for correcting rotational misalignment of a wafer mounted on a film frame comprises: a wafer table providing a wafer table surface configured to securely hold a film frame thereon; a wafer inspection system having a first image capture device configured to perform an inspection process on a wafer mounted on a film frame and held by a wafer table surface; a second image capture device configured to capture at least one image of a plurality of portions of a wafer mounted on a film frame; and a film frame handling apparatus configured to transfer the film frame with the wafer mounted thereon to the wafer table surface and configured to rotate the film frame to correct any rotational misalignment of the wafer relative to the film frame, the first image capture device, and/or the second image capture device. The wafer inspection system can be configured to begin the inspection process without the need for an established film frame registration process involving mating engagement of the film frame alignment features with a set of registration elements.

The first image capturing device can be separate from or the same as the second image capturing device. For example, the second image capture device can be separate from the wafer inspection system, and the second image capture device can be configured to capture at least one image of portions of the wafer on the film frame prior to placement of the film frame on the wafer table surface (e.g., while the film frame is in motion).

The system further includes a processing unit configured to analyze at least one image of a plurality of portions of the wafer mounted on the film frame by executing program instructions for performing image processing operations on the at least one image to determine a rotational misalignment angle and a rotational misalignment direction of the wafer relative to a field of view of the film frame or the first or second image capture devices. The image processing operation is configured to identify one or more wafer structural and/or visual features including at least one of a wafer flat and a set of wafer gridlines; and, where possible, identify one or more film frame structural and/or visual features including film frame flats.

The film frame handling apparatus is configured to rotate the film frame in a direction opposite to the misalignment direction by an angular extent corresponding to the rotational misalignment angle. Correction for rotational misalignment of the wafer is performed without reducing film frame handling throughput or inspection process throughput, for example, during transport and prior to placement of the film frame on the wafer table surface by the film frame handling apparatus.

The film frame handling apparatus can include: a main body; a plurality of vacuum elements coupled to the body and configured to engage a portion of a boundary of the film frame by way of negative pressure, the plurality of vacuum elements being controllably displaceable laterally relative to a common axis corresponding to a center of the film frame in directions toward and away from the common axis to a plurality of different positions; and a capture positioning assembly for positioning the plurality of vacuum elements at each of the different positions to facilitate engagement of the plurality of vacuum elements with the film frame boundaries, wherein each of the different positions corresponds to a different film frame size.

The film frame handling apparatus can also include a plurality of displaceable capture arms carrying a plurality of vacuum elements and coupled to the body; a rotational misalignment compensation motor configured to selectively and simultaneously rotate the plurality of capture arms in a common direction about the common axis so as to accurately correct rotational misalignment of the wafer relative to the film frame; and a vertical displacement drive configured to controllably displace the plurality of capture arms in a vertical direction perpendicular to the surface of the wafer table. In various embodiments, the film frame handling apparatus is configured to place the film frame directly on the wafer table surface.

According to one aspect of the disclosure, a process for correcting rotational misalignment of a wafer mounted on a film frame comprises: capturing at least one image of a wafer mounted on a film frame using an image capture device prior to a beginning of an inspection process of the wafer by a wafer inspection system (e.g., an optical inspection system); digitally analyzing the at least one image by means of an image processing operation to determine a rotational misalignment angle and a rotational misalignment direction of the wafer relative to a set of reference axes of a field of view of the film frame and/or the image capture device; the wafer is corrected for rotational misalignment relative to a set of reference axes of a field of view of the film frame and/or the image capture device by means of a film frame handling apparatus separate from the inspection system.

Due to the capture and analysis of the at least one image and the correction of the rotational misalignment of the wafer based on such analysis, a film frame registration process in which a set of film frame structural features are aligned relative to a corresponding set of registration elements configured to matingly engage with the set of film frame structural features can be avoided prior to starting the inspection process.

The process further includes transferring the film frame to a wafer table surface corresponding to a wafer table of the inspection system. Such transfer of the film frame to the wafer table surface can include placing the film frame directly on the wafer table surface. The capturing of at least one image and the correction for rotational misalignment of the wafer can be performed prior to placing the film frame on the wafer table surface. The capturing of the at least one image can be performed while the membrane frame is in motion. Alternatively, the capturing of the at least one image can be performed after the film frame has been transferred to the wafer table surface. Thus, the capturing of the at least one image can be performed by means of an image capturing device separate from or forming part of the inspection system.

Determining the rotational misalignment angle and the rotational misalignment direction includes performing image processing operations on at least one captured image to detect an orientation of one or more wafer structures and/or visual features relative to (i) one or more film frame structures and/or visual features or spatial directions associated with such film frame structures and/or visual features, or (ii) an orientation of a set of reference axes of a field of view of an image capture device. The wafer structure and/or visual features can include a wafer flat and/or a set of wafer gridlines; and the diaphragm frame structure and/or visual features can include diaphragm frame flats.

The correction of the rotational misalignment of the wafer includes rotating the film frame in a direction opposite to the direction of the misalignment by an angular magnitude corresponding to the rotational misalignment. Since the rotational misalignment correction can be performed before the film frame is placed on the wafer table surface, such correction can be performed without reducing film frame handling throughput or inspection process throughput.

Drawings

Fig. 1A is a schematic illustration of a wafer mounted on a film frame that carries the wafer by means of a thin material layer or film that includes the wafer mounted to an adhesive side.

FIG. 1B is a schematic view of a wafer being rotationally misaligned relative to a film frame carrying the wafer.

Fig. 2A is a schematic view of a die properly positioned or aligned with respect to an image capture device field of view (FOV).

Fig. 2B is a schematic view of a die that is not properly positioned relative to the image capture device FOV or misaligned relative to the image capture device FOV.

Fig. 2C is a schematic diagram illustrating that capturing the entire surface area of a die, such as the rotationally misaligned die shown in fig. 2B, may require up to four images depending on the degree of misalignment of the die relative to the FOV.

Figure 2D is a schematic view of a wafer properly mounted on and aligned relative to a film frame and an inspection process wafer travel path along which an image capture device captures images of the entire surface area of each die within a successive row of dies on the wafer.

Fig. 2E is a schematic view of the wafer 10 rotationally misaligned relative to the film frame and an inspection process wafer travel path along which the image capture device captures images of less than the entire surface area of each die within a successive row of dies on the wafer.

FIG. 2F is a schematic diagram of an array of dies within which the overall surface area of all dies within the array of dies is less than the FOV of the image capture device, and since the horizontal and vertical sides of each die within the array of dies are each substantially parallel to the FOV horizontal axis X_IAnd FOV vertical axis Y_ISuch that the array of dies is properly aligned with respect to the FOV.

FIG. 2G is a schematic diagram of an array of dies for which the horizontal and vertical sides of the dies within the array of dies do not have horizontal and vertical axes X relative to the FOV_IAnd Y_IAnd (4) proper alignment.

Fig. 2H is a schematic view of a single die having a surface area greater than the FOV of the image capture device, where this die is properly aligned with respect to the FOV,because the horizontal and vertical sides of the die are substantially parallel to the FOV horizontal and vertical axes X, respectively_IAnd Y_I。

FIG. 2I is a schematic diagram of a single die, such as shown in FIG. 2H, for which the die side is at the horizontal and vertical axes X with respect to the FOV_IAnd Y_ICauses some portions of the die to remain outside the FOV of the image capture device.

Fig. 3A is a schematic diagram illustrating a portion of a wafer and/or film frame handling system that provides a single multi-aperture wafer table structure for handling wafers and film frames, and further provides rotational misalignment correction, non-planarity repair, and/or lateral shift prevention, according to an embodiment of the present disclosure.

Fig. 3B is a schematic diagram illustrating a portion of a wafer and/or film frame handling system that provides a single multi-aperture wafer table structure for handling wafers and film frames, and further provides rotational misalignment correction, non-planarity repair, and/or lateral shift prevention, according to an embodiment of the present disclosure.

Fig. 4A is a perspective view of a wafer table chassis comprising a non-porous material, such as a ceramic-based non-porous material, according to an embodiment of the present disclosure.

Fig. 4B is a perspective cross-sectional view of the chassis of fig. 4A taken along line a-a'.

Fig. 5A is a perspective view of the chassis of fig. 4A with a moldable, conformable, or flowable porous material, such as a ceramic-based porous material, disposed therein.

Fig. 5B is a perspective cross-sectional view of a chassis carrying moldable, conformable, or flowable ceramic-based porous material corresponding to fig. 5A taken along line B-B'.

Figure 5C is a cross-sectional view of the vacuum chuck structure after planarization corresponding to the chassis carrying the hardened porous ceramic material of figures 5A and 5B.

Fig. 5D is a cross-sectional view of a vacuum chuck structure corresponding to fig. 5C and carrying a wafer or film frame on a planar vacuum chuck surface, produced or manufactured in accordance with an embodiment of the present disclosure.

Fig. 5E is a perspective view of a representative first wafer having a first standard diameter (e.g., 8 inches) disposed on a vacuum chuck structure, in accordance with an embodiment of the present disclosure.

Fig. 5F is a perspective view of a representative second wafer having a second standard diameter (e.g., 12 inches) disposed on a vacuum chuck structure, in accordance with an embodiment of the present disclosure.

Fig. 5G is a perspective view of a representative third wafer having a third standard diameter (e.g., 16 inches) disposed on a vacuum chuck structure, in accordance with an embodiment of the present disclosure.

Fig. 6A is a perspective view of a ceramic-based vacuum chuck substrate tray including a set of pop-pin guide members according to another embodiment of the present disclosure.

Fig. 6B is a cross-sectional view of the ceramic-based vacuum chuck substrate tray of fig. 6A taken along line C-C'.

Fig. 7A is a perspective view of the chassis of fig. 4A and 4B with a moldable, conformable, or flowable ceramic-based porous material disposed therein.

Fig. 7B is a perspective cross-sectional view of a chassis carrying a moldable, conformable, or flowable ceramic-based porous material corresponding to fig. 7A taken along line D-D'.

Fig. 8 is a flow chart of a representative process of manufacturing a vacuum chuck structure according to an embodiment of the present disclosure.

Figure 9 is a cross-sectional view of a vacuum chuck structure showing an initial volume of moldable ceramic-based porous material slightly beyond the capacity of the chassis before planarization is complete, in accordance with an embodiment of the present disclosure.

Fig. 10A is a schematic diagram illustrating an embodiment of a misalignment inspection system configured to determine a degree of rotational or angular misalignment of a wafer relative to a film frame, according to an embodiment of the present disclosure.

Fig. 10B is a schematic diagram illustrating aspects of determining a degree of rotational or angular misalignment of a wafer relative to a film frame using a misalignment inspection system such as that shown in fig. 10A, according to an embodiment of the present disclosure.

Fig. 10C is a schematic diagram illustrating an embodiment of a misalignment inspection system configured to determine a degree of rotational or angular misalignment of a wafer relative to a film frame, according to an embodiment of the present disclosure.

Fig. 10D is a schematic diagram illustrating aspects of determining the degree of rotational or angular misalignment of a wafer relative to a film frame using a misalignment inspection system such as that shown in fig. 10C in accordance with an embodiment of the present disclosure.

Fig. 11 is a schematic illustration of a set of end effectors including at least one end effector carrying a first handling subsystem registration element.

Fig. 12A is a schematic diagram illustrating aspects of a representative multi-function handling apparatus configured in a combined, integrated, or unified manner as each of a rotation compensation apparatus, a flattening apparatus, and a constraining apparatus to perform wafer and film frame handling operations, according to an embodiment of the present disclosure.

Fig. 12B is a schematic diagram illustrating portions of a capture arm, according to an embodiment of the present disclosure.

Fig. 12C is a schematic diagram of portions of a capture positioning assembly and showing a representative first positioning of a plurality of capture arms at a first position corresponding to a first film frame diameter or cross-sectional area, according to an embodiment of the present disclosure.

Fig. 12D is a schematic diagram illustrating portions of a capture positioning assembly and illustrating a representative second positioning of a plurality of capture arms at a second position corresponding to a second film frame diameter or cross-sectional area that is smaller than the first film frame diameter or cross-sectional area.

Fig. 13A is a schematic view of a film frame carried by a multi-function handling apparatus according to an embodiment of the present disclosure.

FIG. 13B is a schematic diagram showing portions of a multi-function handling apparatus about a pick-and-place Z-axis Z_ppThe rotation compensates for a first angular misalignment of the first wafer relative to the film frame.

FIG. 13C is a schematic diagram showing portions of a multi-function handling apparatus about a pick-and-place Z-axis Z_ppThe rotation compensates for a second angular misalignment of the second wafer relative to the film frame.

Fig. 14A-14B are schematic diagrams of a multi-function handling apparatus positioning capture arm tip elements over portions of a wafer to facilitate secure capture of the wafer on a wafer table surface, according to an embodiment of the present disclosure.

Fig. 15A is a schematic view of a representative wafer held uniformly on the wafer table surface by natural suction and vacuum force applied to the underside of the wafer.

Fig. 15B is a schematic illustration of the wafer of fig. 15A after the vacuum force is stopped and the creation of a gas cushion between the wafer and the wafer table surface after a blow is applied to the underside of the wafer.

Fig. 15C is a schematic illustration of the displacement of the wafer relative to the wafer table surface due to the gas cushion shown in fig. 15B.

Fig. 15D-15E are schematic diagrams of a multi-function handling apparatus for positioning a capture arm and a capture arm tip member relative to a wafer in a manner that limits or constrains lateral displacement of the wafer along a wafer table surface, according to an embodiment of the present disclosure.

Fig. 16 is a flow diagram of a representative process for limiting, controlling, or preventing lateral displacement of a wafer along a wafer table surface in accordance with an embodiment of the present disclosure.

Fig. 17 is a flow diagram of a representative wafer handling process, according to an embodiment of the present disclosure.

Fig. 18 is a flow diagram of a representative film frame handling process according to an embodiment of the present disclosure.

Detailed Description

In the present disclosure, consideration or use of a particular element number in a particular figure or reference in a description of a given element or corresponding descriptive material can encompass the same, equivalent, or similar element or element number identified in another figure or descriptive material associated therewith. The use of "/" in the figures or associated text is understood to mean "and/or" unless stated otherwise. Recitation of specific values or ranges of values herein is understood to not include, or be interpreted to include, the recitation of approximate values or ranges of values.

As used herein, the term "group" corresponds to or is defined as a non-empty Finite organization of elements mathematically representing a cardinality of at least 1 (i.e., a group as defined herein can correspond to a unit, a single state or a single element group or a plurality of element groups) according to known Mathematical definitions (e.g., in a manner corresponding to that described in the following documents, the anti-introduction to physical reading of the Cambridge university Press, of Peter J. Eccles, 1998, "Chapter11: Properties of Fine Sets" (e.g., as described on page 140)). In general, elements of a group can include, or be a system, device, apparatus, structure, object, process, physical parameter or value depending on the type of group under consideration.

For purposes of brevity and to facilitate understanding, the term "wafer" as used herein can encompass an entire wafer, a portion of a wafer, or other type of whole or partial object or component (e.g., a solar cell) having one or more planar surface areas on which a set of optical inspection and/or other processing operations are desired or required. The term "film frame" in the following description generally denotes a support member or frame configured to carry or support a wafer, thinned or backlapped wafer or diced wafer, for example by means of a thin layer or film of material disposed or stretched across a surface region of the film frame, and to which the wafer is mounted or adhered in a manner understood by those skilled in the art. Further, the term "wafer table" as used herein includes apparatus for holding a wafer or film frame during a wafer inspection process or film frame inspection process, respectively, where the term "wafer table" will be understood by those skilled in the art to be equivalent, substantially equivalent, or similar to a wafer chuck, vacuum table, or vacuum chuck. The term "non-porous material" as used herein is intended to mean a material that is at least substantially or essentially impermeable to the flow or transmission of a fluid, such as air or a liquid, therethrough, and thus is at least substantially or essentially impermeable to the communication or transmission of vacuum forces therethrough (e.g., for a non-porous material of a given depth or thickness, such as a depth greater than about 0.50-1.0 mm). Similarly, the term "porous material" is intended to mean a material that is at least substantially or essentially permeable to the flow or transmission of a fluid, such as air or a liquid, therethrough, and thus at least suitably/substantially or essentially permeable to the communication or transmission of vacuum forces therethrough (e.g., for a porous material of a given depth or thickness, such as a depth greater than about 0.50-1.0 mm). Finally, the terms "ceramic-based" and "ceramic-based material" in the context of the present disclosure are intended to denote a material that is monolithic or substantially ceramic in terms of its material structure and properties.

Embodiments according to the present disclosure relate to systems and processes for handling wafers and film frames that provide (a) a single or unified porous wafer table configured to handle wafers and film frames in a manner that facilitates or enables accurate, high throughput inspection processes; and (b) a subsystem, device or element configured to automatically: (i) inadequate vacuum holding to repair the wafer on the wafer table due to wafer warpage or non-planarity; (ii) preventing lateral displacement of the wafer due to cessation of vacuum force and/or application of a blow gas; and/or (iii) correct or compensate for rotational misalignment of a wafer carried by the film frame. Several embodiments in accordance with the present disclosure are directed to systems and processes capable of providing each of the foregoing.

While various embodiments according to the present disclosure relate to wafer and film frame inspection systems (e.g., optical inspection systems), several embodiments according to the present disclosure can additionally or alternatively be configured to support or perform other types of wafer and/or film frame front-end or back-end processing operations (e.g., testing operations). For the sake of brevity and to facilitate understanding, aspects of representative embodiments according to the present disclosure are described in detail below in a manner that will primarily emphasize inspection systems.

By virtue of the single or unified wafer table being configured to handle both wafers and film frames, embodiments according to the present disclosure eliminate the need for or the elimination of a wafer table conversion kit, thus eliminating production downtime due to wafer-to-film frame and film frame-to-wafer conversion kit exchanges and calibration operations, thereby enhancing average inspection process throughput. A single or unified wafer table according to embodiments of the present disclosure facilitates or enables high accuracy inspection operations by: a wafer table surface with high or very high planarity is provided that maintains the wafer die surface on a common inspection plane with minimal or negligible deviation from the wafer table surface in a direction along a normal axis parallel to the high planarity wafer table surface.

In addition, embodiments according to the present disclosure can eliminate the need for manual intervention, which was required in the past to address: (a) lack of wafer retention on the wafer table surface due to wafer warpage or non-planarity; and (b) unpredictable lateral movement of the wafer along the wafer table surface following interruption or cessation of the vacuum force holding the wafer to the wafer table surface and/or the instantaneous application of a positive pressure gas stream blown by the wafer table to the underside of the wafer in order to remove any residual vacuum suction. Furthermore, embodiments according to the present disclosure can eliminate the need for manual intervention or mechanical complexity and the otherwise expensive rotatable wafer table assembly required in the past to correct rotational misalignment of the wafer relative to the film frame upon which the wafer is placed (e.g., when the misalignment of the wafer relative to the film frame exceeds a given threshold misalignment magnitude).

Aspects of representative System configurations and System elements

Fig. 3A is a block diagram of a system 200 for handling wafers 10 and film frames 30, the system 200 including a wafer table assembly 610 having a single or unified wafer table 620, the wafer table 620 providing a surface 622 with high or very high planarity, the surface 622 configured to handle wafers and film frames during inspection processes (e.g., wafer inspection processes and film frame inspection processes, respectively) of an inspection system 600, according to an embodiment of the present disclosure. System 200 further includes first handling subsystem 250 and second handling subsystem 300 configured to (a) transfer wafers 10 and film frames 30 to inspection system 600 and transfer wafers 10 and film frames 30 from inspection system 600; and (b) providing wafer rotational misalignment correction and wafer non-planarity repair with respect to the film frame as part of a pre-inspection handling operation and lateral displacement prevention as part of a post-inspection handling operation, as will be described in further detail below.

Depending on whether the wafer 10 or the film frame 30 is being inspected at a given time, the system 200 includes a wafer source 210, such as a wafer cassette, or a film frame source 230, such as a film frame cassette, respectively. Similarly, if the wafer 10 is inspected, the system 200 includes a wafer destination 220, such as a wafer cassette (or a portion of a processing station); and if the film frame 30 is inspected, the system 200 includes a film frame destination 240 that can be a film frame cassette (or part of a processing system). The wafer source 210 and the wafer destination 220 can correspond to or be the same location or structure (e.g., the same cassette). Similarly, the film frame source 220 and film frame destination 240 can correspond to or be the same location or structure (e.g., the same film frame cassette).

The system 200 also includes a wafer pre-alignment or alignment station 400 configured to establish an initial or pre-inspection alignment of the wafer 10 such that the wafer 10 is properly aligned relative to the inspection system 600; a rotational misalignment inspection system 500 configured to receive, acquire, determine, or measure a rotational misalignment direction and a rotational misalignment magnitude (e.g., capable of being indicated by a rotational misalignment angle) corresponding to a wafer 10 mounted on a film frame 30; and a control unit 1000 configured to manage or control aspects of system operation (e.g., via execution of stored program instructions), as will be described in detail below. The control unit 1000 can include or be a computer system or computing device that includes a processing unit (e.g., a microprocessor or microcontroller), memory (e.g., including fixed and/or removable Random Access Memory (RAM)) and Read Only Memory (ROM)), a communication source (e.g., standard signaling and/or network interfaces), a data storage source (e.g., hard disk, optical disk, etc.), and a display device (e.g., flat panel display).

In various embodiments, system 200 additionally includes a support structure, base, chassis, or chassis coupled to or configured to support or carry at least second handling subsystem 300, such that second handling subsystem 300 is capable of forming an operational interface with first handling subsystem 250 and processing system 600 to facilitate wafer or film frame handling operations. In some embodiments, support structure 202 supports or carries each of first handling subsystem 250, second handling subsystem 300, wafer alignment station 400, misalignment inspection system 500, and inspection system 600.

Fig. 3B is a block diagram of a system 200 for handling wafers 10 and film frames 30 according to another embodiment of the present disclosure, the system 200 providing a single or unified wafer table 620 configured to handle wafers and film frames during inspection by the inspection system 600, and further providing a first handling subsystem 250 and a second handling subsystem 300. In this embodiment, the wafer source 210 and the wafer destination 230 are the same (e.g., the same cassette); and the film frame source 220 and film frame destination 240 are the same (e.g., the same film frame cassette). Such an embodiment can provide a smaller or significantly reduced space contact area, resulting in a compact, space efficient system 200.

In the exemplary embodiment, inspection system 600 is configured to perform 2D and/or 3D optical inspection operations with respect to wafer 10 and film frame 30. The optical inspection system 600 can include a plurality of illumination sources, an image capture device (e.g., a camera) configured to capture images and generate image data sets corresponding thereto, and optical elements configured to perform some or each of the following processes in a manner understood by those skilled in the art: directing illumination toward the wafer 10, directing illumination reflected from the wafer surface toward a particular image capture device, reflecting or applying an optical effect (e.g., filtering, focusing, or collimating) on illumination incident on and/or reflected from the wafer surface. The optical inspection system 600 further includes or is configured to communicate with a processing unit and memory by executing stored program instructions to analyze the image data set and generate an inspection result.

As previously mentioned, the inspection system 600 can include or alternatively be another type of processing system that requires or requires one or more of the following: (a) a wafer table 620 configured to handle the wafer 10 and/or film frame 30, which provides a wafer table surface 622 that has very high planarity to integrally hold the wafer dies 12 on a common plane with negligible planar deviation during processing operations; (b) proper alignment of the wafer 10, which shows an amount of misalignment relative to the film frame 30 that exceeds a threshold magnitude of misalignment (e.g., the maximum wafer relative to the film frame rotational misalignment tolerance that should or must be met for maximum throughput inspection, e.g., as will be described in detail below with reference to fig. 10A-10D); (c) uniform secure retention of the wafer 10 or the film frame 30 including the non-planar or warped wafer 10 by the wafer table 620; and/or (d) prevent unwanted, unpredictable, or uncontrolled lateral wafer displacement along the wafer table surface 622.

With further reference to fig. 3C, a wafer table 620 carried by wafer table assembly 610 provides an outer or exposed wafer table surface 622 of high planarity upon which wafer 10 and film frame 30 can be placed and securely held or retained such that wafer die 12 are along a normal axis Z defined orthogonal to the midpoint, center, centroid or approximate midpoint, center or centroid of wafer table surface 622 of high planarity_wtThe parallel directions are maintained entirely on the common examination plane with minimal or negligible plane deviation. Wafer table assembly 610 is configured to selectively or controllably displace wafer table 620, and thus, relative to axis Z, along each of the axes corresponding to or defining a plane_vtTwo transverse spatial axes of traverse (e.g., wafer table X and y axes X, respectively)_vtAnd Y_vt) Carrying or securely holding any wafer 10 or film frame 30.

The wafer table 620 is configured to selectively and securely hold or retain the wafer 10 or film frame 30 on the wafer table surface 622 by a combination of: (a) an inherent or natural suction force that exists due to a pressure differential between atmospheric pressure acting on the top, upper or exposed surface of the wafer and the bottom or underside of the wafer; and (b) selectively controlling the application of vacuum force or negative pressure to the underside of the wafer 10. The wafer table 620 can be further configured to apply or deliver a short/transient (e.g., approximately 0.50 seconds or 0.25-0.75 seconds) positive air pressure jet (e.g., a blow) to the interface between the wafer table surface 622 and the underside of the wafer 10 or film frame 30 after the applied vacuum force is discontinued or stopped in order to relieve the vacuum suction force from the wafer table surface 622 on the wafer 10 or film frame 30.

In various embodiments, the wafer table assembly 610 includes a set of pop-pins 612 that can be selectively or controllably oriented in a perpendicular direction (parallel to or along the wafer table Z-axis Z) relative to the wafer table surface 622_wt) Is shifted upwards to be opposite to the surface of the wafer table622 vertically displaces the wafer 10 or the membrane holder 30. In various embodiments, the wafer table 620 includes a single set of pop-pins 612 (e.g., three pop-pins) configured to handle a plurality of standard size wafers 10 (e.g., 8 inch, 12 inch, and 16 inch wafers 10). The wafer table 620 need not include and additional sets of pop-pins 612 (e.g., additional sets of three pop-pins) can be omitted or not included due to the positioning of a single set of pop-pins 612 on the wafer table 620 (e.g., positioned to carry an 8-inch wafer somewhat near, substantially near, or near its perimeter). As described in detail below, in several embodiments, although the pop-pins 612 can be used in connection with the transfer of the wafer 10 to the wafer table 620 and from the wafer table 620, there is no need to involve the transfer of the film frame 30 to the wafer table 620 and/or from the wafer table 620, and the use of the pop-pins 612 can be omitted or eliminated entirely.

In various embodiments, the wafer table 620 has the same, essentially the same, substantially the same, or similar structure as the wafer table described below with reference to fig. 4A-9.

Aspects of a representative unified wafer table structure for wafer and film frame handling

In embodiments according to the present disclosure, the wafer table structure can include a base tray (or base, frame, form, library, or storage structure) having a plurality of ridges (e.g., can include or be protrusions, ridges, raised bars, dividers, corrugations, creases, or folds) integrally formed from or attached to an interior or base surface of the wafer table structure (e.g., the bottom of the base tray). In various embodiments, the substrate tray can include at least one type of non-porous material (e.g., a ceramic-based material). The substrate tray is intended to be impermeable to a gas or fluid (e.g., air), or substantially impermeable to a gas or fluid, in response to application of a vacuum force. That is, a non-porous material is intended to be impermissible or substantially impermissible to the passage of gas, fluid, or vacuum forces in response to an applied vacuum force. The non-porous material is further intended to be easily machinable, easily sandable or easily ground by common techniques and equipment (e.g., conventional sanding wheels). In various embodiments, the non-porous material can comprise or be porcelain.

The ridges define, delineate, divide, or segregate the substrate tray into a plurality of compartments, chambers, cell structures, open areas, or recesses into which at least one type of moldable, conformable, or flowable porous material can be introduced, provided, deposited, or poured and cured or hardened. The porous material can be further securely bonded (e.g., chemically bonded (e.g., associated with a hardening, curing process)) or adhered to the substrate tray compartment such that the hardened porous material is securely retained within or bonded to the compartment. Additionally or alternatively, the ridges can be shaped such that the porous material when hardened or cured within the compartment is securely held therein by the structure of the ridges. The ridges can be structured to include curved and/or overhanging portions, or have other suitable shapes, as desired or required.

The porous material within the compartment is intended to allow the passage of a gas or fluid (e.g., air) in response to the application of a vacuum force thereto, such that the gas, fluid, or vacuum force can be communicated or transmitted therethrough (e.g., after having been cured or hardened and applied with a vacuum force). Furthermore, the porous material is intended to be easily machined, ground or ground by common techniques and equipment (e.g., conventional grinding wheels).

The choice of non-porous substrate tray material for the wafer table structure and/or the porous material introduced into the substrate tray compartment depends on the desired or required characteristics of the wafer table structure in relation to the application or process to be performed on the wafer 10 or film frame 30 to be placed thereon. For example, optical inspection of small or ultra-small dies 12 of a large diameter diced wafer 10 carried by a film frame 30 requires that the wafer table structure provide a wafer table surface with very high or ultra-high planarity. Furthermore, the selection of the non-porous base tray material and/or the porous compartment material can depend on the chemical, electrical/magnetic, thermal or acoustic requirements that the wafer table structure should meet in view of the anticipated or desired type of wafer or film frame processing conditions to which the wafer table structure will be exposed.

In various embodiments, the non-porous substrate tray material and the porous compartment material are selected to be implemented based on material properties or qualities that will facilitate or enable the implementation of abrading or grinding on multiple exposed surfaces of at least two distinguishable or different materials utilizing a single abrading or grinding device (e.g., substantially simultaneously). More particularly, the exposed surfaces of two (or more) distinguishable or different non-porous and porous materials can be processed, ground or sanded simultaneously in the same manner (e.g., by means of standard processing, grinding or sanding equipment involving operations in accordance with standard processing, grinding or sanding techniques). Such machining, grinding or abrading of each of the non-porous and porous materials results in less, minimal or negligible damage to the machining, grinding or abrading element, device or tool, such as the abrading head. Further, in various embodiments, the non-porous substrate tray material and the porous compartment material are selected such that the rate at which the non-porous substrate tray material is affected (e.g., planarized) by such processing, grinding or abrading is substantially the same as the rate at which the porous compartment material is affected (e.g., planarized) by such processing, grinding or abrading.

For purposes of brevity and ease of understanding, in the representative embodiments of the wafer table structures described below, the non-porous substrate tray material comprises a non-porous material that is either ceramic-based, and the porous cell material comprises a porous material that is either ceramic-based. Those skilled in the art will appreciate that wafer table structures according to embodiments of the present disclosure are not limited to the types of materials provided in connection with the representative embodiments described below.

When it is desired or required to produce a very flat, highly planar or hyperplane wafer table surface, the porous material can comprise a moldable ceramic-based porous material and/or other materials suitable for use according to the subject matterQuasi/conventional processing techniques, processing sequences or processing parameters (e.g., hardening temperature or temperature range and corresponding hardening time or time interval) form, fabricate or produce a compound of a porous wafer table, wafer chuck, vacuum table or vacuum chuck in a manner understood by those skilled in the art. In various embodiments, the porous material can comprise or be a commercially available material provided by CoorsTek inc., Hillsboro, ORUSA, 503-. Such porous materials can include one or more types of ceramic-based materials, for example, alumina (Al)₂O₃) And silicon carbide (SiC), and can exhibit a post-hardening/post-curing pore size in the range of about 5-100 μm (e.g., about 5, 10, 30, or 70 μm) and a porosity in the range of about 20-80% (e.g., about 30-60%). The pore size of the porous compartment material can be selected based on application requirements, such as a desired or required level of vacuum force, suitable for the application in question (e.g., inspection of thin or very thin wafers 10 on the membrane frame 30), as will be understood by those skilled in the art. It can be a process (e.g., by means of a unified or individual machining or grinding process) corresponding to working (e.g., by means of a uniform or individual machining or grinding process) a portion of the ceramic substrate tray (e.g., the set of ridges and possibly also the outer substrate tray edge) and the exposed upper or outer surface of the hardened moldable porous ceramic material carried by the substrate tray compartment to provide a common wafer table surface exhibiting very high or ultrahigh planarity or planar uniformity, which is suitable for securely holding a wafer or film frame, for example, during inspection, in a manner that efficiently arranges or holds the wafer die surface along or within the common plane (normal axis perpendicular to the wafer table surface) with minimal or negligible deviation.

Fig. 4A is a perspective view of a ceramic-based substrate tray 100, and fig. 4B is a perspective cross-sectional view of the substrate tray of fig. 4A taken along line a-a', according to an embodiment of the present disclosure. As described above, in various embodiments, the ceramic-based substrate tray 100 is non-porous or substantially non-porous, and thus is not permitted or substantially not permitted to gas, fluid, or vacuum force transmission therethrough in response to an applied vacuum force. That is, the ceramic-based substrate tray 100 is generally intended to serve as an impermeable barrier that is strong, very strong, or effective to the communication or transmission of gas, fluid, or vacuum forces therethrough.

In an embodiment, the substrate tray 100 has a shape defining a center or centroid 104, with respect to which the vacuum openings 20 can be arranged or around which center or centroid 104; plane or transverse spatial extent or region A_T(ii) a An outer edge or boundary 106; a plurality of inner bottom surfaces 110a-c that can include a plurality of vacuum openings 20 disposed therein; and one or more ridges 120a-b (e.g., arranged in a ring or concentric circle) disposed between the center of the substrate tray and its outer edge 106. As described in detail below, in various embodiments, the ridges 120a-b and the outer edge 106 of the substrate tray are sized, shaped, and/or sized in a manner related to or corresponding to standard wafer and/or film frame sizes (e.g., 8 inch, 12 inch, and 16 inch wafers and one or more film frame sizes corresponding to such wafer sizes). The substrate tray 100 further includes at least one underside surface 150, most or all of which, in various embodiments, is disposed or substantially disposed on a single substrate tray underside plane.

In several embodiments, the vertical base tray axis Z_TCan be defined as perpendicular or substantially perpendicular to the underside surface 150 of the base tray and the inner bottom surface 110a-c of the base tray, and extends through the center or centroid 104 of the base tray. As understood by those skilled in the art, the vertical base tray axis Z_TIs defined as being perpendicular to the desired planar surface of the wafer table upon which the wafer or film frame can be securely held. In FIG. 4A and FIG. 4B, Z_TCan be perpendicular to a line a-a' bisecting each vacuum opening 20.

Each ridge 102a-b borders an inner bottom surface 110a-c of the base tray 100, and each ridge 120a-b depicts, separates or partitions portions of different base tray inner bottom surfaces relative to one another to define a set of base tray compartments or bases 130a-b capable of receiving or carrying the aforementioned moldable, conformable or flowable porous materials. More specifically, in the embodiment shown in fig. 4A, the first ridge 120a extends over and surrounds (e.g., concentrically surrounds) the first inner bottom surface 110a of the base tray 100. The continuous or substantially continuous structural depression defined by the first ridge 120a surrounding or encircling the first interior bottom surface 110a thereby defines a first base tray compartment or base 130a having the first interior bottom surface 110a as its bottom surface. In a similar manner, the first and second ridges 120a, 120b extend above the second inner bottom surface 110b of the base tray 100. The second ridge 120b closes the first ridge 120a (e.g., the first and second ridges 120a-b are concentric with respect to each other) such that the first and second ridges 120a-b define a second continuous or substantially continuous base tray compartment or base 130b having the second inner bottom surface 110b as a bottom surface thereof. Also similarly, the outer edge 106 of the base tray closes the second ridge 120b (e.g., the second ridge 120b and the outer edge 106 are concentric with respect to each other) such that they define a third continuous or substantially continuous base tray compartment or base 130c having a third inner base tray surface 110c as a bottom surface thereof. Any given ridge 120 has a width across the base, such as approximately 1-4mm (e.g., approximately 3 mm); and a corresponding ridge depth, such as approximately 3-6mm (e.g., approximately 4mm), that defines the depth of the compartment or base 130. As described in detail below, in various embodiments, any given substrate tray compartment or base 130a-c has a spatial extent, planar surface area, or diameter that correlates or corresponds to a spatial extent, planar surface area, or diameter of a standard wafer and/or film frame size, shape, and/or dimension.

In alternative embodiments, similar considerations as previously described apply to the definition of additional or other types of substrate tray compartments or bases 130, such embodiments including embodiments having a single ridge 120; embodiments having more than two ridges 120 a-b; and/or embodiments in which one or more ridges 120 are not completely enclosed by each other or are not circular/concentric with respect to one or more other ridges 120 (e.g., when portions of a particular ridge 120 are arranged laterally, radially, or otherwise with respect to another ridge 120). One skilled in the art will readily appreciate the manner in which ridges 120 exhibiting various shapes, sizes, dimensions, and/or portions (e.g., the ridges 120 can include a plurality of different or separate portions arranged relative to an elliptical, circular, or other type of geometric profile or pattern) can define different types of substrate tray compartments or mounts 130.

In addition to the foregoing, the outer edge 106 of the substrate tray and each ridge 120a-b includes an exposed outer edge upper surface 108 and an exposed ridge upper surface 122a-b, respectively, which corresponds to an upper surface or side of the substrate tray 100 that is opposite the lower side surface 150 of the substrate tray and is intended to be closest to the wafer 10 or film frame 30 carried by the wafer table planar surface. In various embodiments, the vertical distance (e.g., parallel to the central transverse axis Z of the base tray) between the outer edge upper surface 108 of the base tray and the inner bottom surfaces 110a-c of the base tray, and between each of the ridge upper surfaces 122a-b and the inner bottom surfaces 110a-c of the base tray_T) Defining a base tray compartment depth D_TC. The vertical distance between the outer edge upper surface 108 of the substrate tray and the underside surface 150 of the substrate tray defines the overall substrate tray thickness T_OT. Finally, the vertical distance along which the vacuum opening 20 extends can be defined to be equal to T_OTAnd D_TCVacuum channel depth D of difference therebetween_V。

Fig. 5A is a perspective view of the substrate tray 100 of fig. 4A into which a moldable, conformable, or flowable porous material has been introduced, arranged, or provided into the substrate tray 100 effective to provide for facilitating or effectuating the formation of the wafer table structure 5 or forming the wafer table structure 5 in accordance with an embodiment of the present disclosure. Fig. 5B is a perspective sectional view of the substrate tray 100 carrying porous material corresponding to fig. 5A taken along line B-B'. Fig. 5C is a cross-sectional view of the substrate tray 100 carrying a porous material corresponding to fig. 5A and 5B.

In fig. 5A and 5B, the porous material can be considered to be located in substrate tray compartments 13/0a-c in either a pre-cure/pre-set or post-cure/post-set state, depending on the stage of fabrication of the wafer table structure under consideration. Furthermore, if considered in a post-cured/post-placement state, the porous material and the non-porous or vacuum non-porous ceramic-based substrate tray 100 can likewise be considered in a pre-planarization/pre-processing or post-planarization/post-processing state, depending on the stage of fabrication of the wafer table structure under consideration. The stages of a representative wafer table structure fabrication process according to embodiments of the present disclosure are described in detail below.

Considering fig. 5A-5C and in relation to the substrate tray embodiment shown in fig. 4A and 4B, after introducing, placing, depositing or providing the porous material into the substrate tray compartments 130a-C and integrating the porous material into the internal geometry of the substrate tray compartments 130a-C, the first substrate tray compartment 130a is filled with a first volume 140a of porous material; filling the second substrate tray compartment 130b with a second volume 140b of porous material; and a third base tray compartment 130c is filled with a third volume 140c of porous material. Similar considerations apply to other substrate tray embodiments having a different number and/or different configuration of compartments 130. That is, after the porous material has been introduced into the substrate tray compartments 130, each of such compartments 130 is filled with a given amount 140 of porous material corresponding to the size or volume of any given compartment 130 under consideration. The initial volume 140 of porous material introduced into any given substrate tray compartment 130 should equal or exceed the volume of the compartment so that excess porous material can be machined or ground away using a planarization process, as will be described in more detail below.

After introducing the porous material into the compartment 130, a portion of any given volume 140 of porous material is exposed to the plurality of vacuum openings 20 within the compartment 130. More specifically, within a given volume 140 of porous material, the porous material that forms an interface with the base tray inner bottom surface 110 is selectively exposed to one or more vacuum openings 20 disposed or formed within the corresponding base tray inner bottom surface 110. For example, as particularly shown in the embodiments shown in fig. 5B and 5C, the porous material of the first volume 140a is exposed to the vacuum opening 20 disposed at the center of the base tray 100 within the first inner bottom surface 110a of the first base tray compartment 130 a. Similarly, the porous material of the second volume 140b is exposed to the vacuum openings 20 disposed within the second inner bottom surface 110b of the second base tray compartment 130 b; also, a third volume 140c of porous material is exposed to the vacuum openings 20 disposed within the third inner bottom surface 110c of the third base tray compartment 130 c. Since the porous material of each volume 140a-c is exposed to a corresponding set of vacuum openings 20, the vacuum force can be selectively communicated, distributed or transmitted through the porous material of each volume 140a-c to the upper surface of the porous material corresponding to the wafer table structure 5. Thus, when the wafer table structure 5 carries a particular size or shape of the wafer 10 or film frame 30 on a planar wafer table surface, vacuum forces can be selectively communicated or transmitted to the underside of the wafer 10 or film frame 30 through the corresponding substrate tray compartment covered by the wafer 10 or film frame 30 disposed on the wafer table planar surface, as will be described in detail below.

As described above and in further detail below, after the porous material volumes 140 have been introduced into the base tray compartment 130, each such volume 140 can be hardened, cured, or bonded (e.g., integrally associated with or simultaneously with the hardening/bonding process) to the inner bottom surface 110 and the associated side surfaces or sidewalls of the one or more ridges 120 defining the compartment 130. In addition, after the hardening/bonding process, the exposed upper surface of the wafer table structure 5, including the exposed upper surface of the porous material of the volume 140, the exposed ridge upper surface 122 and the exposed outer edge upper surface 108, can be processed, ground or planarized at two distinguishable or different material surfaces with a single processing, grinding or abrading device by means of one or more conventional technically simple, inexpensive and robust processing or grinding techniques or processes. In addition, the use of a single processing, grinding or abrading deviceA wafer table planar surface exhibiting very high or ultra-high planar uniformity is now provided or defined. As a result, even for very small die and/or very thin wafers, the die 12 carried by the wafer 10 or film frame 30 arranged and securely held on the wafer table planar surface is held on a common plane so as to effectively hold the upper or exposed die surface on the common plane with minimal or negligible deviation. Thus, the upper surface of such a die 12 follows a normal axis (e.g., corresponding to the vertical axis Z of the substrate tray) parallel to the wafer table surface with high planarity_TWafer table vertical axis Z (overlapping or including)_WT) Exhibit a minimal or negligible positional deviation out of the common plane. The ultra-high planarity of the wafer table surface provided by embodiments according to the present disclosure enables the wafers 10 or die 12 on the film frame 12 located on the wafer table surface to lie substantially in a single plane (e.g., an inspection plane) to facilitate accurate inspection and/or other processing.

Fig. 5D is a cross-sectional view of a wafer table structure 5, produced or manufactured according to an embodiment of the present disclosure, which corresponds to fig. 5C, and which carries a wafer or film frame on a planar wafer table surface. The wafer table structure 5 provides a wafer table planar surface 190 with very high or ultra-high planar uniformity such that die 12 (e.g., very small and/or very thin die 12), devices or material layers carried by the wafer 10 or film frame 30 that are securely held on the wafer table planar surface by vacuum forces are integrally or collectively held, substantially held, or very substantially held on a wafer or film frame processing plane 192 (e.g., optical inspection plane) and along a wafer table vertical axis Z_WTHas a minimal or negligible positional deviation or displacement relative to the wafer or film frame processing plane 192 (or equivalently, in a direction toward or away from the wafer table planar surface 190). In a representative embodiment, the exposed or upper surface of the die 12, having a planar surface area in the range of about 0.25-0.50 square millimeters or more and a thickness of about 25-50 microns or more, can be collectively exhibited with respect to the waferOr a vertical deviation of the processing plane of the film frame of less than about + -100 μm or less than about 10-90 μm (e.g., less than about + -20 to 80 μm or less than about 50 μm on average). Very small or ultra-small die 12 (e.g., about 0.25-0.55 square millimeters) and/or very thin or ultra-thin die 12 (e.g., about 25-75 μm or about 50 μm thick) can be held within the inspection plane 192 such that their deviation from the inspection plane 192 is less than about 20-50 μm.

As described above, the maximum transverse diameter or dimension of the porous material of a given volume 140 within a particular substrate tray compartment 130 and the planar spatial extent or surface area spanned by the ridges 120 defining or limiting the maximum planar spatial extent or surface area of the compartment 130 in which the porous material of the volume 140 is placed are related or correspond to a particular standard or expected wafer and/or film frame size, planar spatial extent or surface area, dimension or diameter. More specifically, to securely hold a given size wafer 10 or film frame 30 to the wafer table planar surface 190, vacuum force is provided or transmitted to the wafer 10 or film frame 30 by selectively providing or transmitting vacuum force to or from vacuum openings 20 exposed to or disposed within the compartments 130 or compartments 130, the compartments 130 having a maximum transverse dimension or diameter that most closely matches the transverse dimension or diameter of the wafer or film frame size currently under consideration, and each compartment 130 corresponding to a wafer or film frame size that is smaller than the wafer 10 or film frame 30 currently under consideration. Thus, a particular size wafer 10 or membrane holder 30 should entirely cover (a) the upper surface of the porous material of the volume 140 having a transverse dimension or diameter that most closely matches the size of the wafer 10 or membrane holder 30 currently under consideration and (b) the upper surface of the porous ceramic material of each volume 140 having a smaller transverse dimension or diameter. The wafer 10 or film frame 30 should also cover a portion of the ridges 120 that most closely matches the size of the wafer 10 or film frame 30 and each ridge 120 having a diameter that is smaller than the wafer 10 or film frame 30 under consideration.

Fig. 5E is a perspective view of a representative first wafer 10a having a first standard diameter (e.g., 8 inches) disposed on the wafer table structure 5, such that the first wafer 10a can be securely held on the wafer table planar surface 190 by: (a) the first wafer 10a covers the porous material of the first volume 140a and covers at least a portion of the transverse width of the first ridges 120a but does not extend to or overlap with the porous material of the second volume 140 b; and (b) applying or transferring a vacuum force to the first wafer 10a by selectively or preferentially providing a vacuum force to or through the vacuum opening 20 of the first compartment, to and through the porous material of the first volume 140a, to the underside of the first wafer 10 a.

Fig. 5F is a perspective view of a representative second wafer 10b having a second standard diameter (e.g., 12 inches) disposed on the wafer table structure 5, in accordance with an embodiment of the present disclosure. The second wafer 10b can be held securely on the wafer table planar surface 190 by: (a) the second wafer 10b covers the porous material of the first and second volumes 140a-b and covers at least a portion of the transverse width of the second ridges 120b but does not extend to or overlap with the porous material of the third volume 140 c; and (b) applying or transferring a vacuum force to the second wafer 10b by selectively or preferentially providing a vacuum force to or through the vacuum openings 20 of the first compartment and the vacuum openings 20 of the second compartment, to and through the porous material of the first and second volumes 140a-b, to the underside of the second wafer 10 b.

Fig. 5G is a perspective view of a representative third wafer 10c having a third standard diameter (e.g., 16 inches) disposed on the wafer table structure 5, in accordance with an embodiment of the present disclosure. The third wafer 10c can be held securely on the wafer table planar surface 190 by: (a) the third circle 10c covers the porous material of the first, second and third volumes 140a-c and covers a portion of the transverse width of the outer edge 106 of the substrate tray; and (b) applying or transferring a vacuum force to the third wafer 10c by selectively or preferentially providing a vacuum force to or through the vacuum openings 20 of the first compartment, the vacuum openings 20 of the second compartment, and the vacuum openings 20 of the third compartment, to and through the porous material of the first, second, and third volumes 140a-c, to the underside of the third wafer 10 c.

In addition to the above, in various embodiments, the ceramic-based base tray 100 can include or be formed to receive or provide one or more additional types of structural features or elements. Certain representative, non-limiting embodiments of such ceramic-based trays 102 will be described in detail below.

Fig. 6A is a perspective view of a ceramic based wafer table substrate tray 100, the substrate tray 100 including a set of pop-pin guide features 160, according to another embodiment of the present disclosure. FIG. 6B is a cross-sectional view of the ceramic based wafer table substrate tray of FIG. 6A taken along line C-C'. In such embodiments, the substrate tray 100 can have a general or unitary structure similar to or substantially the same as described above. However, the first ridge 110a includes a plurality of pop-pin guide structures, elements or features 160a-c (e.g., three in various embodiments, sufficient to enable three pop-pins to handle each of 8 inch, 12 inch and 16 inch wafers corresponding to such wafer sizes). Each pop-pin guide member 106a-c is shaped and configured to provide an opening 162 that corresponds to or defines a passageway or path through which the pop-pin can travel. In various embodiments, any given pop-pin guide member 160a-c can be formed as an integral part or extension of the first spine 110a such that the pop-pin guide member 160a-c protrudes into a portion of the first compartment 120 a. In addition, the pop-pin guide components 1760a-c are sized and/or configured such that substantially no, negligible or minimal vacuum loss occurs during use of the wafer table structure (e.g., during pop-pin raising and lowering). In several embodiments, the pop-pin guide members 160a-c can be strategically positioned such that a single set of pop-pins 164 can handle each wafer and film frame size that the wafer table structure 5 is designated to handle. Those skilled in the art will appreciate that the pop-pin guide members 160a-c can alternatively or additionally be formed separate from the first ridge 110a, or as part of another ridge 110 (e.g., the second ridge 110 b).

Fig. 7A is a perspective view of the substrate tray 100 of fig. 6A and 6B into which a moldable, conformable, or flowable porous material has been introduced, provided, or disposed. Fig. 7B is a perspective cross-sectional view of a substrate tray 100 carrying moldable porous material corresponding to fig. 7A taken along line D-D'. It should be noted that when moldable porous material is introduced into base tray 100, opening 162 within each pop-pin guide member 160a-c and through pop-pin guide member 160a-c should be sealed or blocked so that porous material does not enter opening 162 and the path through which its corresponding pop-pin guide member 160a-c passes in order to ensure that hardened moldable porous material does not interfere with the travel of pop-pins 163a-c through this path and opening 162 during pop-pin actuation involving the lowering or raising of a wafer or film frame relative to wafer table planar surface 190.

In some embodiments, the substrate tray 100 can carry, include, or incorporate a plurality of heating and/or cooling elements. For example, the heating element can comprise a resistive heating element. The cooling element can include a pipe, tube, or passage configured to carry a cooling substance or fluid (e.g., a cooling gas or liquid); or a thermoelectric cooling device. The heating and/or cooling elements can be enclosed or encapsulated within a ceramic-based non-porous substrate tray material (e.g., integrally formed within one or more portions of the substrate tray 100). Alternatively, the heating and/or cooling element can be located outside of the ceramic-based non-porous substrate tray material, enclosed or encapsulated within a portion of the porous material occupying the substrate tray base 130. In addition to or as an alternative to the foregoing, the ceramic-based non-porous substrate tray 100 and/or the porous material occupying the substrate tray base 130 can carry, include, or incorporate additional other types of elements, such as electrodes, temperature sensing elements (e.g., thermocouples), other types of sensing elements (e.g., accelerometers, vibration sensors, or optical sensors), and/or other types of sensing elements configured to sense ambient/environmental conditions within or outside a portion of the wafer table structure 5.

Fig. 8 is a representative process 170 for fabricating the wafer table structure 5 in accordance with an embodiment of the present disclosure. In an embodiment, the wafer table fabrication process 170 includes a first process portion 172 that involves providing a ceramic-based non-porous wafer table substrate tray 100 having a plurality of compartments 130 therein; a second processing portion 174 that involves providing a moldable porous material; and a third processing section 176 comprising introducing a moldable porous material into the plurality of compartments 130 and filling the volumetric geometry of each compartment 130 within the plurality of compartments 130 with the moldable porous material such that the moldable porous material integrates into or occupies the internal spatial dimensions of each compartment 130. Within each compartment 130, a depth D beyond the substrate tray compartment 130 is exhibited in a manner shown in FIG. 9 or generally shown by means of a moldable porous ceramic material_TCThe initial volume 142 of moldable porous ceramic material can exceed or slightly exceed the volumetric capacity of the compartment 130.

The fourth process portion 178 involves hardening or curing the moldable porous ceramic material and bonding the porous material to the interior surfaces defining each compartment 130 (i.e., the interior bottom surface 110 within the base tray and the compartment side walls corresponding to the ridges 120). Once the porous material is securely held within or bonded to the compartment interior surfaces, the fifth processing portion 180 involves machining or grinding the porous material (i.e., each porous material volume 140) and portions of the substrate tray 110 such as the exposed upper surface 108 of the substrate tray outer edge 106 and the exposed upper surface 122 of the substrate tray ridge 120 so as to simultaneously provide the exposed, upper or outer surface of the porous material volume 140, the exposed upper surface 122 of the substrate tray ridge 120, and the exposed upper surface 108 of the substrate tray outer edge 106 with a very high planarity, thereby defining a wafer table planar surface 190 upon which a high uniformity of the wafer and film frame can be securely held. Once planarized, each porous material volume 140 corresponding to any given compartment 130 is the same or substantially the same volume as the compartment 130.

The sixth processing portion 182 involves coupling or mounting the planarized wafer table structure 5 to a displaceable wafer table assembly (e.g., an x-y wafer table) and coupling the vacuum opening of the planarized wafer table structure 5 to a set of table assembly vacuum lines, links and/or valves so that a vacuum force can be selectively actuated and applied to the wafer 10 or film frame 30 disposed on the wafer table planar surface 190.

In contrast to certain prior art wafer table designs in which regions of porous material are separated by spacers made or substantially made of one or more metals and/or utilize an outer pedestal structure made or substantially supported by one or more metals, various embodiments of a wafer table structure according to the present disclosure avoid or eliminate ridges 120 made or substantially made of one or more metals, and generally further avoid or eliminate base trays 100 made or substantially made of one or more metals. More specifically, in prior art wafer table designs that include an upper or exposed non-porous wafer table surface that is at least partially or substantially made of metal and an upper or exposed porous wafer table surface that is at least substantially made of ceramic material, such metal surface has very different machining, grinding or polishing characteristics, properties or behavior than the porous ceramic material surface. During the machining, grinding or polishing process, the metal surface will not planarize at the same rate or ease as the surface of the porous ceramic material. In addition, metal surfaces can easily damage standard machining, grinding or abrading elements, devices or tools (e.g., sanding heads). The inclusion of a metal surface makes machining, grinding or polishing a wafer table structure with a processing arm made according to embodiments of the present disclosure more difficult, more expensive and more time consuming.

Furthermore, the difference between the machining, grinding or abrading characteristics of the exposed metal surface and the exposed porous ceramic surface significantly increases the likelihood that the finally-manufactured wafer table surface will exhibit an undesirable or unacceptable non-planarity or insufficient planarity at one or more portions or areas of the wafer table surface. Such prior art wafer table designs are therefore not well suited for inspection of large diameter and thin wafers 10 having fragile dies 12 thereon (e.g., 12 inch or larger diced wafers 10 carried by a film frame 30 carrying small or ultra-small dies 12). In contrast, wafer table structure embodiments according to the present disclosure do not suffer from this drawback and provide a highly uniform or ultra-uniform planar wafer table surface 622 that is well suited for inspection of such types of wafers 10 or film frames 30.

The end result of a wafer table structure fabricated in accordance with embodiments of the present disclosure is a wafer table 620 that (a) eliminates or omits grooves or vacuum holes (e.g., drilled vacuum holes) on the wafer table surface 622 that can adversely affect the planarity of the wafer table surface 622 and cause one or more of the aforementioned related problems; (b) a wafer table surface 622 with very high or ultra-high planarity suitable for handling (i) the wafer 10 and film frame 30, thereby eliminating the need for a wafer table conversion kit and (ii) very small or ultra-small die 12 (e.g., 0.5 x 0.5 square millimeters or less) on very thin or flexible wafers (e.g., 75 μm, 50 μm or less) because the planar wafer table surface 622 facilitates positioning and retaining such die 12 on a single plane, which is difficult to achieve using conventional wafer table designs; and (c) are structurally simple, low cost, and easy to manufacture (particularly as compared to conventional wafer table designs that include grooves or machined/drilled vacuum holes on their wafer table surface and exposed metallic material (e.g., a plurality of metallic partitions or plates on the wafer table surface).

Aspects of a representative wafer alignment station

Returning again to the description of the other portions of the system 200 shown in fig. 3A, the wafer (pre) alignment station 400 can comprise substantially any type of alignment apparatus or device configured to establish an initial wafer orientation or alignment relative to a portion or component of the wafer alignment station 400 and/or inspection system 600 based on the position or orientation of one or more wafer alignment features or structures associated with the wafer alignment station 400 or inspection system 600. Such wafer alignment features can include a primary plane and possibly a secondary plane in a manner understood by those skilled in the art. In various embodiments, the wafer alignment station 400 is conventional.

Aspects of a representative misalignment inspection system

As previously described, rotational misalignment of the wafer 10 relative to the film frame 30 can result in a reduction in inspection throughput since more image capture events or film frames will be required before an overall die image of the rotationally misaligned die 12 can be captured and processed. In the following description, a specific embodiment of an apparatus and process for detecting rotational misalignment of a wafer relative to a film frame is described with reference to fig. 3A and 10A-10C.

The misalignment inspection system 500 includes an apparatus or set of devices configured to determine, detect, or estimate a wafer mis-rotation/misalignment direction and a corresponding wafer mis-rotation/misalignment angle, magnitude, or value for a wafer 10 mounted on a film frame 30. Depending on the details of the embodiment, the misalignment inspection system 500 can include a film frame support or positioning apparatus or device; one or more illumination or optical signal sources (e.g., a set of broadband and/or narrowband light sources, e.g., LEDs); and/or one or more illumination or optical signal detectors or image capture devices. The misalignment checking system 500 can also include a processing unit (e.g., within a portion of an embedded system that includes a microcontroller configured to execute program instructions and a memory in which such program instructions can be stored; as well as signal communication or input/output resources).

Various misalignment inspection system embodiments are provided in the following description, wherein the misalignment inspection system 500 in some embodiments is configured to determine the misalignment angle/direction and angular magnitude by optically detecting the orientation of one or more wafer structures and/or visual features, such as a wafer grid line or a set of flats, relative to one or more film frame structures and/or visual features associated with such film frame features, such as film frame registration features 34a-b or spatial directions. In other embodiments, the misalignment inspection system 500 is additionally or alternatively configured to determine the misalignment direction and the misalignment angle magnitude by capturing at least one image of the wafer 10 disposed on the film frame 30 and performing image processing operations involving a comparison between the captured image of the wafer 10 and a set of reference axes corresponding to the FOV50 of an image capture device, such as an image capture device within the misalignment inspection system 500 and/or within the inspection system 600.

Furthermore, as described below, the determination and compensation for wafer to film frame misalignment angle according to embodiments of the present disclosure can avoid, omit, or eliminate mechanical registration of the film frame 30 with respect to the image capture device. Alternatively, in some embodiments, the determination of the wafer to film frame misalignment angle can involve mechanical registration (e.g., as a previous operation or as an initial operation) of the film frame 30 with respect to the image capture device by mating the film frame registration features 34a-b with one or more registration elements in a manner understood by those skilled in the art.

In various embodiments, the determination of the misalignment angle direction and the corresponding misalignment angle magnitude is performed by an image processing operation; and compensating or correcting for rotational misalignment of the wafer relative to the film frame and/or the image capture device FOV on which the wafer is mounted by rotating the film frame by the rotational misalignment angular magnitude in a direction opposite to the misalignment angular direction. Embodiments in accordance with the present disclosure can thus omit or avoid mechanical registration of the film frame 30 with respect to an image capture device (e.g., a first image capture device and/or a second image capture device) by mating engagement of the film frame registration features 34a-b with a set of film frame registration elements or structures.

Fig. 10A is a schematic diagram of a misalignment inspection system 500 configured to determine a range of rotational or angular misalignment of a wafer relative to a film frame 30, in accordance with an embodiment of the present disclosure. In an embodiment, the misalignment inspection system 500 includes an image capture device 540 coupled to the misalignment processing unit 510. The misalignment processing unit 510 is configured to execute program instructions (e.g., software) for determining or estimating the direction and magnitude of the angular misalignment of the wafer 10 relative to the film frame 30. The misalignment processing unit is further in communication with a system controller 1000 configured to communicate with the second handling subsystem 300 and the inspection system 600.

The misalignment inspection system shown in fig. 10A is configured to determine the misalignment of the wafer relative to the film frame by comparing the wafer structural features with the film frame structural features. More specifically, as will be appreciated by those skilled in the art, the individual dies 12 on the wafer 10 may generally be visually identified or separated using grid lines (e.g., horizontal grid lines 6 and vertical grid lines 8). If the horizontal or vertical grid lines 6, 8 of the wafer exhibit a predetermined or standard reference orientation relative to a set of film frame reference features (e.g., the horizontal or vertical grid lines 6, 8 of the wafer are substantially parallel or perpendicular to a particular predetermined film frame reference feature), the wafer 10 is properly aligned relative to the film frame 30, and thus the dies 12 of the wafer will be properly aligned relative to the image capture device FOV of the inspection system (thereby maximizing inspection throughput). On the other hand, if the horizontal or vertical gridlines 6, 8 of the wafer do not exhibit a predetermined or standard reference orientation relative to a set of film frame reference features (e.g., the horizontal or vertical gridlines 6, 8 of the wafer are not substantially parallel or perpendicular to a particular predetermined film frame reference feature), then without correction or compensation for such rotational misalignment of the wafer relative to the film frame, the wafer 10 will be rotationally misaligned relative to the film frame 30 and the dies of the wafer will be misaligned relative to the inspection system image capture device FOV, thereby reducing inspection throughput. In various embodiments, the wafer misalignment angle θ can be determined by correlating or indicating or defining the angular disposition, offset or displacement (e.g., in degrees or radians) of one or more of the wafer gridlines 6, 8 relative to at least one of the film frame flats 35a-d_WTo assert the angular direction and angular magnitude of the misorientation/misalignment of the wafer relative to the film frame 30. Wafer dislocation angle theta_WAn angular misalignment direction (e.g., ± direction) and an angular misalignment magnitude (e.g., in degrees or radians) can be indicated or included.

When the misalignment inspection system of fig. 10A considers the film frame 30, the misalignment inspection system image capture device 540 captures one or more images of the wafer 10 disposed on the film frame 30 and generates corresponding image data. The image captured by the misalignment inspection system image capture device 540 includes (a) one or more wafer areas along which the wafer gridlines 6, 8 extend at least partially (e.g., extend along or across a majority or substantial portion of the surface area of the wafer); and (b) a portion (e.g., a majority or a substantial portion) of the one or more film frame flats 35a-d relative to which the angular orientation of the grid lines 6, 8 within the captured image can be determined or estimated. Thus, the misalignment inspection system image capture device 540 is arranged relative to the film frame 30 such that a portion of at least one wafer grid line 6, 8 (e.g., a portion of the length of one or more grid lines 6, 8) and a portion of at least one reference film frame flat 35a-d (e.g., a portion of the length of one or more film frame flat 35 a-d) are located within the misalignment field of view FOV of the image capture device 540_M550 of the substrate.

The aforementioned image data is communicated to the misalignment processing unit 510, and the misalignment processing unit 510 is capable of performing image processing operations (e.g., conventional image processing operations performed by program instruction execution in a manner understood by those skilled in the art) to analyze the image data and determine or estimate the wafer misalignment angle θ_WIndicating the direction and magnitude of the angular misalignment of the wafer 10 relative to the film frame 30 (in a manner correlated to the angular orientation of the captured wafer gridlines 6, 8 relative to the captured film frame flats 35 a-d). Those skilled in the art will appreciate that the capture of at least a certain length or spatial extent (e.g., at least 3-5cm) of one or more wafer gridlines 6, 8 and at least a certain length or spatial extent (e.g., at least 2-4cm) of one or more diaphragm frame flats 35a-d (rather than a small portion of such wafer gridlines 6, 8 and diaphragm frame flats 35a-d, respectively)Capture) is beneficial for enhancing the wafer dislocation angle theta_WAccurate determination of.

FIG. 10B is a block diagram illustrating the determination of a wafer misalignment angle θ by the misalignment inspection system 500, such as that shown in FIG. 10A_WSchematic representation of representative aspects of (1). In the exemplary embodiment of fig. 10A and 10B, the misalignment system image capture device 540 is configured to be able to capture, for the largest film frame 30 that the system 200 is configured to handle (e.g., a film frame 30 carrying a 16 inch wafer 10), at least about 20% -50% (e.g., at least about 25% -33%) of the surface area of the wafer 10 closest to the first film frame flat 35a (e.g., corresponding to the wafer area where the wafer flat or notch 11 is expected to be disposed) and a majority of the length of the first film frame flat 35a proximate that area of the wafer 10 within the misalignment field of view FOVM 550. For smaller film frames 30 (e.g., film frames 30 carrying 12-inch or 8-inch wafers), such a misalignment system image capture device 540 can capture a greater portion of the exposed surface area of such smaller film frames.

In various embodiments, a single misalignment system image capture device 540 can be configured to capture images of each size film frame 30 that the system 200 is configured to hold. Other embodiments can include a plurality of dislocation system image capture devices 540 (e.g., a first image capture device 540 configured to capture a first image corresponding to a first surface area (e.g., a lower surface area) of the wafer 10 and a corresponding first film frame flat 35a and a second image capture device 540 configured to capture a second image corresponding to another surface area (e.g., an upper surface area) of the wafer 10 and a corresponding another film frame flat 35 c). The capturing of the first and second images can be performed simultaneously, substantially simultaneously, or sequentially. The first and second image capture devices can have the same or different displaced field of view FOV depending on the details of the implementation_M550。

In an embodiment, the misalignment processing unit 510 is capable of determining or identifying a reference wafer gridline, e.g., the vertical wafer gridline 6, that is most closely positionedA location near or terminating at the midpoint of the wafer pocket 11 or wafer flat, and a corresponding reference extended virtual or arithmetic grid 568 along which the vertical wafer grid 6 is generated as a line segment can be generated and extended to or through the first flat 35a of the film frame. The misalignment processing unit 510 can additionally determine or estimate the angle between the first film frame flat 35a and the reference extended grid 568, which is the wafer misalignment angle θ_WIn this regard, for example, as shown in FIG. 10B, the misalignment processing unit 510 can determine the actual angle α based on or at an intersection between the reference extended grid line 568 and a determined or calculated line or line segment along which the first diaphragm frame flat 35a is a line segment_WThose skilled in the art will appreciate that the angle may be varied from 90 deg. - α_WTo obtain the wafer dislocation angle theta_W. Other embodiments can additionally or alternatively perform similar or other types of calculations based on standard geometric and/or defocus relationships in a manner understood by those skilled in the art.

The wafer dislocation processing unit 510 can dislocate the wafer by an angle θ_WCommunicate to system control unit 1000 and/or second handling subsystem 300 such that wafer misalignment angle θ_WCan be stored in memory (e.g., in a buffered manner). The second handling subsystem 300 is capable of receiving, acquiring, or accepting a wafer misalignment angle θ corresponding to the film frame 300 being handled_WAnd the whole film frame 300 can be displaced from the wafer by an angle theta_WAnd conversely rotated to correct for misalignment of the wafer relative to the film frame (e.g., under control of program instruction execution).

Fig. 10C is a schematic diagram illustrating a misalignment inspection system 500 configured to determine a range of rotational or angular misalignment of a wafer relative to the film frame 30, according to another embodiment of the present disclosure. In an embodiment, the misalignment inspection system 500 of fig. 10C includes an image capture device coupled to the misalignment processing unit 510 in a manner similar to that described above with reference to fig. 10A and 10B.

As will be appreciated by those skilled in the art,within inspection system 600, an image capture device (e.g., camera) 640 provides an image corresponding to inspection system FOV axis X_IAnd Y_IFOV of field of view_I650. Thus, within the misalignment inspection system 500, the image capture device 540 provides a FOV axis X corresponding to the misalignment inspection system_MAnd Y_MFOV of field of view_M550。

When the carrier has zero misalignment (i.e., has a misalignment angle θ of zero degrees) with respect to the film frame 30_W) When the film frame 30 of the wafer 10 is registered relative to the image capture device 540 of the misalignment inspection system, the horizontal and vertical grid lines 6, 8 of the wafer will be relative to the FOV axis X of the misalignment inspection system_MAnd Y_MHas a predetermined orientation. For example, under such conditions, the horizontal and vertical grid lines 6, 8 of the wafer are aligned with the FOV axis X of the misalignment inspection system_MAnd Y_MParallel or geometrically identical. Similarly, when a film frame 30 carrying a wafer 10 having zero misalignment relative to the film frame 30 is registered relative to the image capture device 640 of the inspection system, the horizontal and vertical grid lines 6, 8 of the wafer will be aligned relative to the inspection system FOV axis X_IAnd Y_IHaving a predetermined orientation (e.g., grid lines 6, 8 of the wafer will be aligned with the inspection system FOV axis X_IAnd Y_IParallel or geometrically coincident).

When considering the film frame 30 for the determination of the misalignment of the wafer relative to the film frame 30, the image capturing device 540 of the misalignment inspection system captures one or more images of the wafer 10 disposed on the film frame 30 and generates image data corresponding thereto. Such image data is communicated to a misalignment processing unit 510, the misalignment processing unit 510 being capable of performing image processing operations (e.g., conventional image processing operations in a manner understood by those skilled in the art) to analyze the image data and to determine a misalignment inspection system FOV axis X based on one or more horizontal wafer gridlines 6 and/or one or more vertical wafer gridlines 8_MAnd Y_MTo determine the wafer misalignment angle theta_W。

FIG. 10D is a block diagram illustrating the determination of a crystal by the misalignment inspection system 500, such as that shown in FIG. 10CSchematic illustration of aspects of the extent of rotation or angular misalignment of the circle relative to the film frame 30. As shown in FIG. 10D, the horizontal and vertical grid lines 6, 8 of the wafer are from the FOV axis X of the misalignment inspection system_MAnd Y_MThe degree of rotation or angular offset defines the wafer dislocation angle θ_W. The wafer dislocation processing unit 510 can dislocate the wafer by an angle θ_WCommunicate to system control unit 1000 and/or second handling system 300 such that wafer misalignment angle θ_WCan be stored in memory and accessed by the second handling subsystem 300 to correct for rotational misalignment of the wafer 10 relative to its film frame 30.

As described in detail below, when second handling subsystem 300 is handling a given film frame 30, second handling subsystem 300 is able to access or retrieve (e.g., from memory) a wafer misalignment angle θ corresponding to film frame 30_WAnd, for example, when the wafer misalignment amplitude exceeds a maximum misalignment angle θ that can be predetermined, programmable, or selectable_W-Max(i.e., when θ_W＞θ_W-MaxIn time), the film frame 30 is rotated to correct misalignment of the wafer 10 carried by the film frame 30. The industry standard threshold is 15 degrees for rotational misalignment of the wafer relative to the film frame. However, the applicant's experience indicates that over 5 degrees of wafer rotational misalignment relative to the film frame should require adjustment as die 12 are increasingly being made smaller and larger in wafer size. Depending on die size and wafer size, any delay in image capture of the entire die or image of the entire die of image processing and the resulting reduction in inspection processing throughput due to rotational misalignment of the wafer relative to the film frame will be magnified or exacerbated in the case of a large number of dies (e.g., 10000 or more dies, e.g., 20000-plus 30000 dies) carried by a larger wafer. E.g. theta_W-MaxCan be defined as having an angular amplitude of about 10 degrees, 7.5 degrees, 5 degrees, or 3 degrees. In general, the maximum misalignment angle threshold can depend on the die size and the inspection system image capture device FOV 650 associated therewith.

As described further below, secondThe handling subsystem 300 is capable of correcting wafer-to-film-frame rotational misalignment without introducing any delay in film-frame handling operations (i.e., without causing a reduction in film-frame handling or inspection process throughput). For example, second handling subsystem 300 can be at a transport wafer misalignment angle θ_WThe zero or substantially zero amount of time required for the film frame 30 to transfer the film frame to the wafer table surface 622 while rotating the film frame 30 to correct for wafer rotational misalignment relative to the film frame. Thus, in certain embodiments, substantially any wafer rotational misalignment relative to the film frame that can be detected (e.g., reliably or repeatedly detectable) by the misalignment inspection system 500 can be from the maximum misalignment angle threshold θ_W-MaxIndependently communicated to second handling subsystem 300 and/or acted upon second handling subsystem 300 so that second handling subsystem 300 can automatically correct wafer rotational misalignment relative to the film frame for each or substantially each film frame 30 to be inspected without affecting film frame handling throughput and inspection throughput.

In various embodiments, the misalignment inspection system 500 can be independent, separate, or distinct with respect to one or both of the first and second handling subsystems 250, 300. For example, the misalignment inspection system 500 can include or be distinct from each of the first and second handling subsystems 250, 300, can be internal to the system 200, e.g., carried by the support structure 202 of the system. Alternatively, the misalignment inspection system 500 can be external to the system 200 or remote from the system 200 (e.g., in a different room), e.g., disposed remote from the system's support structure 202 and configured to operate at least substantially independently of the system 200 to determine the number of film frames 30 within a film frame carrier corresponding to the wafer angular misalignment direction and magnitude, which can be stored in memory and/or communicated to and/or retrieved by the system's control unit 1000 or second handling subsystem 300 to facilitate wafer misalignment correction operations. In certain embodiments, the misalignment inspection system 500 can also include one or more film frame registration elements (e.g., mechanical registration elements configured to matingly engage with the film frame registration features 34 a-b) such that the misalignment inspection system 500 performs mechanical film frame registration prior to determining the extent to which the wafer is misaligned relative to the film frame.

In particular embodiments, a portion of the misalignment inspection system 500 can include one or more portions of the second handling subsystem 300, the wafer table 620, and/or possibly a portion of the inspection system 600 (e.g., the wafer table assembly 610 and one or more image capture devices). For example, after the film frame 30 is transferred to the wafer stage 620 and placed on the wafer stage 620, the inspection system image capture device 640 can capture a set of captured images of the wafer 10 carried by the film frame 30 and generate one or more corresponding sets of image data. For a wafer 10 carried by a film frame 30 disposed on a wafer table 620, a processing unit coupled to the inspection system 600 can analyze such image data to determine a wafer misalignment angle θ_W. The processing unit can further compare the wafer dislocation angle thetaw to a maximum dislocation angle threshold thetaw_W-MaxTo determine if the magnitude of the wafer misalignment angle exceeds a maximum misalignment angle threshold θ_W-Max. If so, the processing unit can issue a misalignment correction request to the second handling subsystem 300, which second handling subsystem 300 can pick up the film frame 30 from the wafer table surface 622 and rotate the film frame 30 in a direction and angle that corrects or adjusts the misalignment of the wafer 10 relative to its film frame 30. The second handling subsystem 300 can then place the film frame 30 back onto the wafer table surface 622, after which film frame inspection can begin with the proper wafer alignment condition with respect to the inspection system image capture device FOV 650.

In other embodiments, a portion of the misalignment inspection system 500 can include the first handling subsystem 200; plus an image capture device 540 disposed outside of the film frame cassette, wherein the image capture device 540 is configured to capture a set of images of the wafer on the film frame 30 after the first handling subsystem 200 has retrieved the film frame 30 from the film frame cassette. The first handling subsystem 200 can position the film frame 30 under an image capture device 540 of the misalignment inspection system, the image capture device 540 being capable of capturing a wafer carried by the film frame 3010 and communicate corresponding image data to the misalignment processing unit 510 for analysis/processing and to determine a corresponding wafer misalignment angle theta_W. In embodiments where a portion of the first handling subsystem 200, such as the end effector 270, includes a mechanical film frame registration element 282, the film frame 30 can be mechanically registered relative to the first handling subsystem 200 in association with retrieval of the film frame 30 from the film frame cassette. The first handling subsystem 200 is capable of positioning the film frame 30 relative to the image capture device 540 of the misalignment inspection system according to a known or predetermined positioning such that the film frame 30 is positioned relative to the misalignment inspection system FOV axis X_MAnd Y_MMechanically registered.

In yet another embodiment, second handling subsystem 300 can include, implement, or be combined or effectively combined with one or more portions of misalignment inspection system 500. For example, one or more portions of second handling subsystem 300 can include or be positionable relative to a plurality of optical and/or image capturing elements. In some embodiments, after film frame 30 has been transferred to second handling subsystem 300, second handling subsystem 300 is able to determine a wafer misalignment angle θ corresponding to film frame 30_W. The second handling subsystem 300 can then rotate the film frame 30 to correct the wafer misalignment angle θ_WThe indicated wafer is rotationally misaligned relative to the film frame to establish the correct orientation of the dies 12 carried by the film frame 30 relative to the inspection system image capture device FOV 650. The second handling subsystem 300 is also capable of transferring the film frame 30 to the wafer table 622 (e.g., simultaneously with or after the film frame rotates).

Aspects of purely mechanical contrast image processing assisted film frame registration

Those skilled in the art will further appreciate that if the wafer carried by the film frame is properly mounted on the film frame without any or with minimal rotational misalignment relative to the film frame, mechanical registration of the film frame by engaging the film frame registration features 34a-b with the film frame registration elements or structures causes the film frame to be properly aligned relative to the FOV of the inspection system image capture device, which in turn causes the wafer to be properly or acceptably aligned relative to the inspection system image capture device FOV.

However, when the wafer is originally mounted to the film frame, the wafer may be rotationally misaligned relative to the film frame. Thus, when there is rotational misalignment of the wafer relative to the film frame, the mechanical registration of the film frame fails to account for the rotational misalignment of the wafer relative to the inspection system image capture device FOV. In other words, when such rotational misalignment is present, and has a magnitude that exceeds or is outside of the acceptable range, mechanical registration of the film frame with respect to the image capture device FOV is not conducive to ensuring that the wafer is properly aligned with respect to the image capture device FOV.

Various embodiments according to the present disclosure are configured to perform optical or image processing assisted registration of a wafer carried by a film frame with respect to an image capture device FOV involving image processing operations for determining a wafer rotational misalignment angle and a corresponding wafer rotational misalignment direction. Thus, a mechanical membrane holder registration process can be omitted, avoided or excluded. It will be appreciated by those skilled in the art that the elimination of the manufacturing process (e.g., a film frame handling process such as a mechanical film frame registration process involving mating engagement of film frame registration features 34a-b with one or more registration elements) saves time and can therefore increase throughput. Several embodiments according to the present disclosure can make the mechanical film frame registration process unnecessary or redundant, as will be described in detail below. While mechanical film frame registration processes can still be performed in some such embodiments, in various embodiments, mechanical film frame registration processes can be avoided or eliminated.

The embodiment of the misalignment inspection system 500, such as shown in fig. 10A-10B, is configured to determine (via image capture and image processing operations) the wafer misalignment angle θ by determining or analyzing the angular relationship between the wafer structure or visual feature and the film frame structure or visual feature_W. Such an embodiment enables accurate determination of the wafer misalignment angle θ W regardless of, or independent of, whether the film frame 30 has been mechanically registered with respect to the inspection system image capture device FOV 650. Assuming that the second handling subsystem 300 has been registered or aligned with respect to the inspection system image capture device 640 (e.g., as part of its installation, or as an initial or one-time configuration/setup process), once the second handling subsystem 300 has rotated the film frame 30 to correct for the presence of the detected rotational misalignment of the wafer with respect to the film frame, the second handling subsystem 300 can directly transfer the film frame 30 to the wafer table surface 622 so that the dies 12 carried by the film frame 30 are properly aligned and exhibit the correct rotational orientation (e.g., maximum inspection process throughput orientation) with respect to the inspection system image capture device FOV 650. The inspection system 600 can then directly or immediately begin the film frame inspection operation without the need for a separate or additional mechanical film frame registration process prior to inspection of the film frame 30.

Similarly, embodiments of a misalignment inspection system 500, such as shown in fig. 10C-10D, are configured to inspect the wafer structure or visual features by determining or analyzing the wafer structure or visual features and one or more misalignment inspection system FOV axes X_MAnd Y_MThe angle relationship between the two to determine the wafer dislocation angle theta_W. Such an embodiment also enables accurate determination of the wafer misalignment angle θ W regardless of, or independent of, whether the film frame 30 has been mechanically registered with respect to the inspection system image capture device FOV 650. Assuming that the misalignment inspection system image capture device 540 has been registered or aligned with respect to the inspection system image capture device 640 (e.g., as part of its installation, or as an initial or one-time configuration/setup process), then the dies 12 on the film frame 30 are properly aligned with respect to the inspection system image capture device FOV 650 after the second handling subsystem 300 has rotated the film frame 30 to correct for the presence of rotational misalignment of the wafer with respect to the film frame. The second handling subsystem 300 can directly transfer the film frame 30 to the wafer table surface 622 and the inspection system 600 can directly or immediately begin a film frame inspection operationWithout the need for a separate or additional mechanical film frame registration process prior to inspection of the film frame 30.

By (a) a wafer misalignment angle θ independent of whether the film frame 30 has been mechanically registered relative to the inspection system image capture device FOV 650 or independent thereof_WAccurate determination of the misalignment detection system; (b) according to theta_WA second handling subsystem for rotating the film frame 30 (e.g., at and by θ)_WIn the direction opposite to the indicated direction, and by equal to or substantially equal to_WThe indicated angular span of the angular span) to correct for rotational misalignment of the wafer relative to the film frame, thereby providing a properly rotated film frame 30; and (c) the second handling subsystem directly transfers the properly rotated film frame 30 to the wafer table surface 622, which effectively enables optical registration of the film frame 30 relative to the inspection system image capture device FOV 650 in accordance with embodiments of the present disclosure.

Such optical/image processing assisted registration of the film frame 30 relative to the inspection system image capture device FOV 650 can eliminate the need for a mechanical film frame registration process, as long as the accurate and reliable transfer of the film frame 30 from the misalignment inspection system 500 to the second handling subsystem 300 maintains or preserves the rotational orientation or arrangement of each film frame before the second handling subsystem begins the film frame rotation operation. As described in detail below, the transfer of film frame 30 from first handling subsystem 250 to second handling subsystem 300 according to embodiments of the present disclosure ensures or intends to ensure that the time at which the misalignment inspection system 500 captures a set of images of a wafer 10 mounted on the film frame 30 and the second handling subsystem 300 begin to be based on the wafer misalignment angle θ_WAccurately and reliably maintains the rotational orientation of any given film frame 30 between the times of the film frame rotation operations.

Furthermore, in various embodiments, the film frame handling and optically or optically assisted registration sequence avoids introducing additional film frame handling time between the time the film frame 30 is retrieved from the film frame cassette and the time the film frame 30 is placed on the wafer table surface 622The registration sequence involves (a) the misalignment inspection system inspecting the wafers 10 mounted on the film frame 30 and determining the corresponding wafer misalignment angle θ_W(ii) a (b) Transferring film frame 30 from misalignment inspection system 500 to second handling subsystem 300; (c) the second handling subsystem corrects for rotational misalignment of the wafer relative to the film frame, thereby enabling optical/image processing assisted registration of the film frame 30 relative to the inspection system image capture device FOV 650; and (d) the second handling subsystem transfers the properly rotated film frame 30 to the wafer table surface 622. Thus, each of (a), (b), (c), and (d) within the aforementioned film frame handling and optical/image processing based registration sequence avoids reducing film frame handling throughput and thus avoids reducing inspection processing throughput. Furthermore, the omission or elimination of the conventional/purely mechanical film frame registration process, which requires a given mechanical registration time, results in a time saving and thus an increase in throughput. In contrast to embodiments according to the present disclosure, prior art systems and methods fail to recognize that eliminating the mechanical film frame registration process is either desirable or possible.

For further details, as noted in some embodiments, the misalignment inspection system 500 includes an image capture device 540 configured to capture an image of the wafer 10 mounted on the film frame 30 in association with the first handling subsystem transferring the film frame 30 from the film frame cassette to the second handling subsystem 300. For example, the misalignment inspection system image capture device 540 can be disposed over a portion of a film frame travel path along which a first handling subsystem (e.g., a robotic arm 260 coupled to an end effector 270 as described below) transports the film frame 30 to a second handling subsystem 300, such that the misalignment inspection system image capture device 540 captures images of the wafer 10 mounted on the film frame 30 as the film frame 30 moves along the travel path (e.g., "en route"). The misalignment inspection system 500 can then determine the wafer misalignment angle θ in the same, substantially the same, similar, or substantially similar manner as described above_WAnd shifting the wafer by an angle theta_WCommunicating to the second handling subsystem. The first handling subsystem 250 can be paired with a misalignment checking systemAt wafer offset angle theta_WThe film frame 30 is transferred to the second handling subsystem in a manner that accurately and reliably maintains the rotational orientation of the film frame, and thereafter, the second handling subsystem is able to correct the rotational misalignment of the wafer relative to the film frame and transfer the film frame 30 to the wafer table 622. In yet another embodiment, the first handling subsystem 250 can be configured to compensate for rotational misalignment of the wafer 10 mounted on the film frame 30, for example, by rotating the film frame 30 via a rotatable robotic arm assembly that carries the film frame 30 via an end effector.

Similar considerations as described above with respect to the omission, elimination, or significant repetition of the mechanical film frame registration process apply to embodiments in which one or more portions of the misalignment inspection system 500 are combined with the second handling subsystem 300 or implemented by the second handling subsystem 300 such that the second handling subsystem 300 is able to determine the wafer misalignment angle θ_WAn embodiment of (1).

Aspects of a representative first handling subsystem

The first handling subsystem 250 includes at least one end effector-based handling apparatus or device, such as one or more robotic arms 260 coupled to a set of corresponding end effectors 270. The first handling subsystem 250 is configured to perform certain types of wafer handling operations as well as certain types of film frame handling operations. With respect to wafer handling operations, in several embodiments, the first handling subsystem 250 is configured to perform each of the following operations:

(a) acquiring wafers 10 from one or more wafer sources 210 prior to wafer processing by the inspection system 600, wherein the wafer sources 210 can include either wafer carriers/cassettes or additional processing systems or stations;

(b) transferring the wafer 10 to the wafer alignment station 400;

(c) transferring the initially aligned wafer 10 from the wafer alignment station 400 to the wafer table 620 (e.g., by transferring the wafer 10 and positioning the wafer 10 on the pop-pins 612, and subsequently releasing the wafer 10) to facilitate a wafer processing operation;

(d) acquiring the wafer 10 from the wafer table 620 (e.g., by capturing the wafer 10 lifted off the wafer table 620 by the pop-pins 612 and removing the wafer 10 from the pop-pins 612); and

(e) the wafers 10 retrieved from the wafer stations 620 are transported to one or more post-process wafer destinations 220, such as wafer carriers or cassettes or another processing system or station.

With respect to film frame handling operations, in various embodiments, the first handling subsystem 250 is configured to perform each of the following operations:

(a) acquiring film frames 30 from one or more film frame sources 230 prior to film frame processing by inspection system 600, wherein film frame sources 230 can include either film frame carriers/cassettes or additional processing systems or stations;

(b) in some embodiments, an initial film frame registration or alignment (which can be held relative to the wafer table 620 and/or one or more elements of the inspection system 600) is established by aligning, matching, engaging, or pairing the film frame registration features 34a-B relative to the at least one first handling subsystem registration element 282 with a set of end effectors 270a-B including at least one end effector 270a carrying the first handling subsystem registration element 282, wherein the first handling subsystem registration element 282 includes a mating or complementary registration feature 284a-B, such as further described with reference to fig. 11B;

(c) transferring film frame 30 to second handling subsystem 300; and

(d) film frame 30 is retrieved from the second handling subsystem 300 and the received film frame 30 is transferred to one or more post-process film frame destinations 240, which can include film frame carriers or cassettes or film frame processing stations.

In various embodiments, initial registration or alignment of the film frame with respect to the inspection system 600 is established in a conventional manner by means of registration elements carried by the wafer table assembly 610, and the film frame registration features 34a-b are matingly engaged with such registration elements in a manner readily understood by those skilled in the art.

In an embodiment, the first handling subsystem 250 is further configured to (e) position the film frame 30 relative to the misalignment inspection system 500 to facilitate determination and measurement of the angular misalignment magnitude and direction of the wafer relative to the film frame 30 carrying the wafer 10.

Aspects of a representative second handling subsystem

In various embodiments, second handling subsystem 300 is configured to perform the following wafer or film frame handling operations:

the film frame is operated:

(a) exchanging film frame 30 with first handling subsystem 300 (i.e., receiving film frame 30 from first handling subsystem 300 and transferring film frame 30 to first handling subsystem 300); and

(b) the film frame 30 is positioned on the wafer table 620.

Wafer handling:

(c) in connection with the wafer table applying a vacuum force to a non-planar or warped wafer 10 (and automatically/sensor-based determination of vacuum force sufficiency), selectively applying a flat force or pressure to portions of the wafer 10 that cannot be sufficiently, fully, or securely held on the wafer table surface 622 due to the non-planarity or warp; and

(d) the wafer 10 is spatially constrained during release from the wafer table 620, wherein such release can be made by vacuum force cessation and possibly blow gas application and any pop-pin extension.

In certain embodiments, second handling subsystem 300 is configured to establish an initial registration or alignment of the film frame relative to one or more portions or components of inspection system 600 by aligning, mating, engaging, or pairing film frame registration features 34a-b with at least one second handling subsystem registration component (not shown) that includes a mating or complementary registration feature (not shown) in a manner similar or substantially similar to that described above for first handling subsystem 250.

In an embodiment, second handling subsystem 300 is additionally configured to correlate rotational misalignment information (e.g., wafer misalignment angle θ) determined by misalignment inspection system 500 corresponding to wafer 10 mounted on film frame 30_W) The film frame 30 is rotated. Alternatively, the rotational misalignment of the wafer relative to the film frame can be inspected/determined by the inspection system 600 (e.g., if the film frame 30 is located on the wafer table 622, the misalignment inspection system 500 can be part of the inspection system 600 or implemented by the inspection system 600). As described above, the misalignment inspection system 500 can include an image capture device 640 and a wafer table 620 corresponding to the inspection system 600, and the second handling subsystem 300 can be configured to (a) position the film frame 30 on the wafer table 620 so that the misalignment inspection system 500 can determine the direction and magnitude of the angular misalignment of the wafer relative to the film frame, and (b) acquire the film frame 30 from the wafer table 620, correct the misalignment of the wafer relative to the film frame, and (c) subsequently place such film frame 30 on the wafer table 620.

In view of the above, the first handling subsystem 250 is capable of providing a wafer transfer interface for transferring wafers 10 between a wafer table position corresponding to a wafer table pop pin position and a wafer source/destination other than the wafer table 620 or located outside of the wafer table 620. The second handling subsystem 300 is capable of providing a film frame transfer interface between the first wafer handling subsystem 200 and the wafer table 600 for transferring the film frame 30; the membrane frame is rotatably connected with the interface; a wafer flat interface; and a wafer level constraint interface.

As described above, regarding the process for correcting the rotational misalignment of the wafer with respect to the film frame, the second handling subsystem 300 does not need to perform such correction of the rotational misalignment in a stationary state. The rotational misalignment can be corrected on the way of transporting the film frame 30 to the wafer stage 620. This aspect of the design of the second handling subsystem 300 ensures that no time is lost in performing wafer misalignment correction with respect to the film frame. In addition, this method can be implemented for each inspection of the wafer 10 mounted on the film frame 30, since it involves rotating the film frame 30 by a certain magnitude and direction to correct the rotational misalignment of the wafer relative to the film frame without loss of time.

Thus, the second handling subsystem 300 is capable of (a) positioning the film frame 30 on the wafer table 620 in a manner that avoids or overcomes problems associated with rotational misalignment of the wafer 10 relative to the film frame 30, e.g., without loss of processing time to correct the rotational misalignment; (b) removing the film frame 30 from the wafer table 620; (c) the lack or incompleteness of the wafer table 620 to the holding of the wafer table area due to the loss of vacuum force caused by wafer non-planarity or warpage is overcome; and (d) prevent unwanted lateral displacement of the wafer 10 along the wafer table surface 622 after the vacuum force is released or discontinued and any associated blow gas is applied.

In various embodiments, second handling subsystem 300 includes each of the following:

the film frame is operated:

(a) a rotation compensation device configured to automatically rotate the film frame 30 to correct for rotational misalignment of the wafer 10 relative to the film frame 30 (e.g., depending on the angular misalignment reversal and magnitude, possibly taking into account a maximum misalignment angle threshold or tolerance, which can be related to or correspond to a maximum allowable misalignment tolerance of the wafer relative to the film frame); and

(b) a film frame placement and retrieval apparatus ("film frame-wafer table placement/retrieval apparatus") relative to the wafer table is configured to place the film frame 30 on the wafer table surface 622 and remove the film frame from the wafer table surface 622.

Wafer handling:

(a) a flattening apparatus configured to be perpendicular or substantially perpendicular (e.g., parallel to wafer table Z-axis Z) to wafer table surface 622 in association with application of vacuum force by wafer table 620_wt) In the direction of (1) will forceOr pressure is applied to portions of the wafer 10; and

(b) a restraining or limiting device configured to substantially prevent lateral displacement of the wafer 10 along the wafer table surface 622 after cessation of the vacuum force applied to the wafer 10 by the wafer table 620 to the underside of the wafer 10 and application of any associated blow gases.

In several embodiments, second handling subsystem 300 includes a multi-function handling, transporting, and/or pick-and-place apparatus that combines, integrates, or unifies portions of a rotation compensation apparatus, a flattening apparatus, and a constraining apparatus, as described in detail below.

Aspects of a representative multi-function pick and place device

Fig. 12A-12D are schematic diagrams illustrating aspects of a representative multi-function handling (MFH) apparatus, assembly, unit, or station 300 configured as each combination, integration, or unification of a rotation compensation apparatus, a flattening apparatus, a constraining apparatus, and a film frame-to-wafer table placement/retrieval apparatus to perform wafer and film frame handling operations, in accordance with embodiments of the present disclosure. In an embodiment, the MFH apparatus 300 includes each of the following:

(a) a body, frame assembly or housing 302;

(b) a plurality of displaceable capture arms 310 coupled to the housing 302 configured to (i) selectively capture, securely hold, and selectively release different sizes, or diameters of the film frame 30 by application or cessation of vacuum force provided to portions of the periphery or boundary of the film frame, and (ii) selectively restrain or prevent lateral displacement of the wafer 10 along the wafer table surface 622;

(c) a set of vacuum elements (e.g., vacuum linkages, lines, and/or valves) 318 coupled to the plurality of capture arms 310 that facilitate control of the vacuum force or negative pressure applied to the film frame 30 by the plurality of capture arms 310;

(d) capture positioning setA member 320 including a capture arm displacement motor or drive 330 and a displacement linkage 334 coupled to the plurality of capture arms 310 to controllably position the plurality of capture arms 310 in a pick-and-place Z-axis Z toward or away from a common axis (e.g., corresponding to or approximately corresponding to a midpoint, center, or centroid of a wafer 10 carried by the film frame 30 or a wafer 10 carried thereby_PP) Is laterally displaced relative to the common axis to a plurality of different positions or distances, wherein towards or away from Z_PPEach such different position or distance of (a) can correspond to a different membrane holder size, dimension, or diameter.

(e) A rotational misalignment compensation motor or drive 340 configured to selectively and simultaneously rotate about a common axis of rotation (e.g., a pick-and-place Z-axis Z)_PP) Rotating each of the plurality of capture arms 310 in a common direction (i.e., collectively rotating the plurality of capture arms 310);

(f) a support member or arm 352 configured to carry the housing 302; and

(g) a vertical displacement motor or driver 350 configured to move along a Z-axis Z parallel to the wafer table, e.g., by vertical displacement of the housing 302_wtAnd pick-and-place Z-axis Z_ppA vertical direction (i.e., perpendicular or substantially perpendicular to the wafer table surface 622) that selectively or controllably displaces the plurality of capture arms 310.

In some embodiments, the MFH apparatus 300 can be arranged relative to the misalignment inspection system image capture device 540 or configured to carry, implement, or communicate with the misalignment inspection system image capture device 540, the misalignment inspection system image capture device 540 configured to capture images of the film frame 30 in the manner described or indicated above with reference to fig. 10A-10D. For example, the MFH device housing 302 can carry within its housing 302 a set of optical and/or image capturing elements, such as an image capturing device 540 including a set of image sensors. Alternatively, the housing 302 can be disposed below such an image capture device 540 (in which case one or more portions of the housing can include one or more openings for image capture therethrough). As yet another alternative, the housing 302 can carry a set of optical elements, such as a microlens array, which can be coupled to a fiber optic bundle and configured to communicate optical or imaging signals corresponding to the image of the membrane rack to an image capture device (e.g., a camera) that can be disposed outside of the housing 302 or remote from the housing 302. In such embodiments, the set of optical elements can include a plurality of illumination sources (e.g., LEDs).

Fig. 12B is a schematic illustration of portions of a capture arm 310, according to an embodiment of the present disclosure. In an embodiment, each capture arm 310 includes an arm component 312 that is substantially transverse to the pick-and-place Z-axis Z_ppIn a direction or substantially transverse to the pick-and-place Z-axis Z_ppExtend in the plane of (a); and a corresponding terminal portion or end portion 314 that is substantially parallel to Z_ppIn a direction projecting or extending from the arm member 312. Each arm member 312 and its corresponding end portion 314 includes a channel or passageway therethrough configured to communicate, provide, or supply a vacuum force. In addition, each end portion 314 carries, includes, or is coupled to a soft and elastically deformable or soft tip element 316 that facilitates secure vacuum retention of the membrane frame (e.g., by way of the end portion positioned at a peripheral or outer boundary of the membrane frame 30) with positioning adjacent to or upon the surface of the wafer 10, minimal or negligible unwanted air intrusion or vacuum leakage, and a reduced, minimal or negligible likelihood of introducing damage or defects.

Exemplary Membrane Rack Capture and Release aspects

FIG. 12C is a schematic view of portions of the capture positioning assembly 320 and illustrates the plurality of capture arms 310 in a pick-and-place Z-axis Z away from a cross-sectional area or diameter corresponding to the first film frame, according to an embodiment of the present disclosure_ppOr a representative first location at a radial distance. FIG. 12C is a schematic diagram showing portions of capture positioning assembly 320, and showing a plurality of capture arms 310 at exit Z_ppCorresponding to a second diaphragm frame having a diameter or cross-sectional area smaller than that of the first diaphragm frameA representative second location of the diameter or cross-sectional area or radial distance.

The capture arm positioning motor 330 is configured to position the plurality of capture arms 320 relative to each other and the pick-and-place Z-axis Z_ppSelectively oriented such that the plurality of capture arms 320 can be selectively arranged relative to or at a plurality of capture locations, wherein each capture location corresponds to a different membrane rack size, dimension, area, or diameter. In the embodiment shown in fig. 12B-12C, selective positioning of the plurality of capture arms 310 is performed by way of pulleys 332 a-e. More specifically, any given capture arm 310a-d is coupled to a corresponding pulley 332a-d in a manner that facilitates rotation of its arm component 312a-d about the central axis of the capture arm corresponding to pulley 332 a-d; and the pulleys 332a-d corresponding to each capture arm 310a-d are mechanically coupled or linked to each other by means of a shifting linkage 334, which can be, for example, a belt. The additional pulley 332e can be configured to adjust, provide, control, or select the amount of tension on the displacement linkage 334. The capture arm positioning motor 330 is coupled to one of the pulleys 332d that serves as a drive pulley 332 d.

The rotational motion or force applied to the drive pulley 332d by the capture arm positioning motor 330 results in a simultaneous or substantially simultaneous and precise and controlled rotation of each pulley 332a-e by means of the shifting linkage 334, and thus a simultaneous rotation of each arm component 312a-d about the central axis of its corresponding pulley 332 a-d. Rotation of arm members 312a-d causes tip elements 314a-d of each capture arm to move toward or away from pick-and-place Z-axis Z, depending on the direction in which motor 330 rotates drive pulley 332d_ppIs radially displaced or translated in the direction of (a). Thus, tip elements 314a-d corresponding to multiple capture arms 310 are arranged to facilitate each tip element 314a-d being disposed away from Z_ppIn a manner transverse to the pick-and-place Z-axis Z_ppOr in a direction opposite to the pick-and-place Z-axis Z_ppCollectively shifted or translated on a common transverse plane. Tip elements 314a-d away from Z_ppCorresponds to and facilitates different sizes, dimensions, and dimensionsOr a diameter (e.g., a larger or smaller diameter) of the diaphragm frame 30. The ability of the tip element 316 to move radially equidistant toward or away from Zpp also facilitates a gentle depression or hold down of the wafer 10 (e.g., warped wafer 10) in connection with the wafer handling process described in detail below.

Once the plurality of capture arms 310 are disposed at exit Z_ppAt a radial distance corresponding to the size of the considered diaphragm frame 30, the plurality of capturing arms 310 can be positioned such that the capturing arm tip elements 316 are in contact with the peripheral portion of the diaphragm frame 30. The vacuum can then be activated such that a vacuum force or negative pressure is applied to the peripheral portion of the membrane holder 30 by the plurality of capture arms. The plurality of capture arms 310 can securely carry or hold the film frame 30 by means of an applied vacuum force. Similarly, the plurality of capture arms 310 can release the film frame 30 by virtue of the cessation of the applied vacuum force.

In various embodiments, MFH apparatus 300 is configured to be positioned relative to portions of first handling subsystem 250 (e.g., end effector 270) such that plurality of capture arms 310 are capable of capturing film frame 30 from first handling subsystem 250. For example, when the end effector 270 has captured the film frame 30, the end effector applies a vacuum force or negative pressure on the peripheral portion of the underside of the film frame in a manner understood by those skilled in the art. When the end effector 270 of the first handling subsystem carries the film frame 30, the plurality of capture arms 310 can be positioned above the end effector 270 and above an upper or top side or surface of the film frame 30. The plurality of capture arms 310 can then be vertically displaced relative to the end effector 270 (e.g., using a vertical displacement motor 350 and/or a vertical displacement of a robotic arm 260 coupled to the end effector 270) such that the plurality of capture arm tip elements 316 contact a peripheral portion of the top surface of the membrane rack. During such vertical displacement of the plurality of capture arms 310, a vacuum can be activated such that a vacuum force or negative pressure flows through the plurality of capture arms. A set of vacuum sensors coupled to second handling subsystem 300 is capable of automatically monitoring the vacuum pressure within the vacuum lines coupled to plurality of capture arms 310. Once the plurality of capture arms 310 are in contact with the peripheral portion of the upper side of the film frame, the plurality of capture arms 310 can be securely attached to or capture the film frame 30 by means of the vacuum force transmitted therethrough. After the vacuum sensor detects that the vacuum force has exceeded a suitable capture threshold, the end effector 270, which has held a portion of the underside of the film frame, can release the vacuum force that he has applied to the underside of the film frame, thereby releasing the film frame from the end effector 270 and completing the transfer of the film frame 30 to the MFH apparatus 300.

In a manner similar to that described above, the MFH apparatus 300 is vertically displaceable relative to the wafer table 620 so as to capture a film frame 30 carried by the wafer table 620 (e.g., a film frame that has been held on the wafer table 620 by a vacuum force applied to the underside of the film frame 30). In such cases, although in some embodiments wafer table 620 is capable of maintaining such application of vacuum force to the underside of film frame 30 until (substantially until or nearly until) the vacuum force capture of the film frame by MFH apparatus 300 is complete, wafer table 620 need not maintain its application of vacuum force to film frame 30 during the entire transfer of film frame 30 to MFH apparatus 300 (e.g., since lateral displacement of film frame 30 along wafer table surface 622 is unlikely to occur even in the absence of wafer table vacuum force).

In view of the above, once the MFH apparatus 300 has transported the film frame 30 that it captures or securely carries to a given destination (e.g., above the end effector 270 or vacuum table surface 622), the film frame 30 can be transported or unloaded to the destination of interest and released. When the destination of the unloading is the end effector 270 or wafer table 620, the MFH apparatus 300 will maintain its capture and secure retention of the film frame 30 until secure capture of the film frame 30 by the end effector 270 or wafer table 620 has occurred (e.g., as determined by a vacuum sensor coupled to the end effector 270 or wafer table 620 in a manner readily understood by those skilled in the art). The MFH apparatus 620 can then be shifted away from the unload destination (e.g., vertically relative to the end effector 270 or the wafer table 620).

Aspects of representative wafer rotational misalignment compensation

Once the film frame 30 has been captured by the plurality of capture arms 310, the rotational misalignment compensation motor 340 can be selectively actuated to correct or compensate for the rotational misalignment of the wafer 10 carried by the film frame 30. Relative to the pick-and-place Z-axis Z by the entire wafer carrier 30 depending on the direction of the offset and the offset amplitude or angle determined for the wafer 10_ppTo perform such misalignment compensation.

Fig. 13A is a schematic diagram of a membrane rack 30 carried by an MFH apparatus 300 according to an embodiment of the present disclosure. The wafer 10 supported on the film frame 30 is angularly misaligned relative to the film frame 30 by more than a misalignment threshold amplitude value θ_W-Max(e.g., a maximum allowable misalignment threshold, such as a programmable, selectable predetermined number of degrees) of degree or angle, the misalignment compensation motor 340 can cause the film frame 30 to rotate in a direction opposite to the direction of wafer misalignment by an angular span, arc length, or degree that corresponds to, is equal to, or approximately equal to the determined magnitude of misalignment for the wafer 10. When the MFH apparatus 300 places such a rotated film frame 30 on the wafer stage 620 of the inspection system, the wafer 10 carried by the film frame 30 will have a correct or proper rotational alignment (i.e., an almost zero degree angular misalignment) with respect to the image capture device 640 of the inspection system. This correction of the rotational misalignment of the wafer can thus ensure that the die 12 is properly aligned relative to the FOV 650 of the image capture device.

In various embodiments, the diaphragm mount rotation of the MFH apparatus 300 is performed by means of a simultaneous or collective rotation of each capture arm 310 within the plurality of capture arms 310 about the pick-and-place z-axis Zpp, for example, by rotation of the housing 302 to which the capture arms 310 are coupled. In several embodiments, the misalignment compensation motor 340 provides, includes, or is coupled to a rotatable shaft 342 configured to rotate the housing 302; and a rotary motion encoder or rotary encoder configured to control the direction and extent of rotation of the housing in a manner understood by those skilled in the art.

FIG. 13B is a Z-axis taken about a pick-and-place Z-axis according to an embodiment of the disclosure_ppA schematic diagram of the MFH apparatus 310 rotated by a first misalignment compensation amount, magnitude, angle, or angular path length in a first misalignment compensation direction to compensate or correct for a first angular misalignment of the first wafer 10a relative to the film frame 30. FIG. 13C surrounds Z according to embodiments of the present disclosure_ppA schematic diagram of the MFH apparatus 310 rotated by a second misalignment compensation amount, magnitude, angle, or angular path length in a second misalignment compensation direction to compensate or correct for a second angular misalignment of the second wafer 10b relative to the film frame 30.

When the film frame 30 carrying the misaligned wafer 10 is carried by the MFH apparatus 300, the housing 302 is at an angle equal to or substantially equal to the misalignment angle θ of the misaligned wafer in a direction opposite to the angular direction of misalignment of the wafer_WThe rotation of the angle of (a) compensates for or corrects the misalignment of the wafer, thereby establishing the correct or proper orientation of the wafer relative to one or more elements of the inspection system 600 (e.g., the image capture device or the FOV provided thereby). The rotated film frame 30, and thus the properly oriented wafer 10 carried by the film frame 30, can then be transferred to the inspection system 600. Further, such rotation of the film frame 30 by the MFH apparatus 300 to compensate for rotational misalignment of the wafer relative to the film frame (e.g., film frame rotation "en route" during film frame transport) can be performed while the MFH apparatus 300 is moving (e.g., while the MFH apparatus 300 is transporting the film frame 300 to the wafer table 620). Thus, after or during rotation of the housing 302 by a first misalignment amount, magnitude, angle or angular path length in a first misalignment compensation direction as shown in fig. 13A, the film frame 30 carrying the first wafer 10a can be transferred to the wafer stage 620 so that inspection can begin with a maximum throughput wafer die oriented with respect to OFV. Similarly, after or during rotation of the housing 302 in the second misalignment compensation direction by a second misalignment compensation amount, magnitude, angle, or angular path length as shown in fig. 13B, the film frame 30 carrying the second wafer 10B can be transferred to the wafer table 620 for inspection.

Since the film frame 30 that has been transferred to the wafer table 620 may have been rotated to compensate or correct for the angular misalignment of the wafer 10 supported by the film frame 30, in several embodiments, the film frame registration operation is performed away from the wafer table 620 or away from the wafer table surface 622 (otherwise, any film frame registration elements carried by the wafer table 620 would need to be rotated or repositioned depending on the degree to which the film frame 30 has been rotated). Thus, according to various embodiments of the present disclosure, wafer table assembly 610 or wafer table 620 need not include and can omit or exclude film frame registration elements or mechanisms such as one or more film frame registration elements 282 of the type described above with reference to first handling subsystem 250.

Furthermore, as described above, in some embodiments, the MFH apparatus 300 is capable of determining and correcting the wafer misalignment angle θ without, omitting from, or eliminating the film frame registration process (a) prior to film frame capture by the MFH apparatus 300, and (b) prior to the start of a film frame inspection operation in which the MFH apparatus has been directly transferred to the film frame 30 of the wafer table surface 622 after the inspection system has corrected for any such rotational misalignment of the wafer relative to the film frame_W. As a result, such embodiments of the MFH apparatus 300 can facilitate or enable elimination of such film frame registration processes during film frame handling, thereby saving time and increasing throughput.

Aspects of representative film frame transfer

In various embodiments, the MFH apparatus 300 is configured to transport the film frame 30 to the wafer table 620, for example, by positioning or placing the film frame 30 directly on the wafer table surface 622. In several embodiments, the vertical displacement motor 350 is configured to move in a direction parallel to the pick-and-place Z-axis Z_ppAnd the wafer Z-axis Z_wtVertically displace the housing 302 a particular or predetermined distance in the direction of each, thereby placing or positioning the film frame 30 and its wafer 10 directly on the wafer table surface 622. In such embodiments, the placement of the film frame 30 on the wafer table surface 622 and/or the retrieval of the film frame 30 from the wafer table surface 622 need not involve and the use of the wafer table pop-pins 612 can be omitted, avoided or eliminated. The diaphragm in question has been displaced in the housing 302After the frame 300 is close to, adjacent to, or substantially at or on the distance of the wafer table surface 622, a vacuum force can be applied by the wafer table assembly 620 in a manner understood by those skilled in the art to securely engage, capture or hold the film frame 30 and its corresponding wafer 10 on the wafer table surface 622. In association with the placement of the film frame 30 on the wafer table surface 622 and the secure capture or retention of the film frame 30 thereon, the vacuum force applied to the film frame 30 by the plurality of capture arms 310 can be released and the vertical displacement motor 350 can displace or lift the housing 302 and, correspondingly, the plurality of capture arms 310a given distance away from the wafer table surface 622.

The transfer of the film frame 30 held by the MFH apparatus 300 to the first handling subsystem 200 can occur in a manner similar to that described above, for example, by the first handling subsystem positioning an end effector 260 coupled to a robotic arm 260 under or below the plurality of capture arms 310. Although the embodiments described herein describe the MFH apparatus 300 in detail as being configured for z-axis displacement, the MFH apparatus according to the present disclosure is not limited to only z-axis motion.

Aspects of representative wafer warpage or non-planarity repair

If the wafer 10 warps, the next desired processing (e.g., inspection of the wafer) to be performed on the wafer stage 620 cannot be performed. Without manual intervention, the wafer inspection or manufacturing process is about to stop, causing a loss of throughput. Embodiments according to the present disclosure provide for automatic correction or repair responses when wafers 10 placed on wafer table 620 are automatically detected as warped, thus eliminating or substantially eliminating the need for manual intervention and thus eliminating or effectively eliminating downtime or downtime of the inspection system due to warped wafers 10, thereby increasing inspection throughput (e.g., an average inspection throughput determined/calculated based on the number of warped wafers 10 expected within one or more inspection lots).

In association with and/or subsequent to the first handling subsystem handling the wafer 10 to the wafer table surface 622, activation or application of a vacuum force to the wafer table 620 (e.g., by activating one or more vacuum valves) is required or desired in order to securely engage, capture, or retain the wafer 10 on the wafer table surface 622 (e.g., by a vacuum force applied to the entire surface area of the underside of the wafer 10). However, when the wafer 10 includes one or more portions that are non-planar, substantially non-planar, or warped, the wafer 10 may not be able to be securely held on the wafer table surface 622 (e.g., depending on the degree of warping). Loose, improper, insufficient, or improper engagement of the wafer 10 on the wafer table surface 622 can be indicated by a determination of whether the magnitude of the applied vacuum force or negative pressure (e.g., automatically provided or output by a vacuum gauge) exceeds or falls below an acceptable vacuum engagement pressure threshold (e.g., which can be programmable, selectable, or a predetermined value).

In accordance with the present disclosure, various embodiments of the MFH apparatus 300 are configured to selectively apply or transfer one or more vacuum bonding-assisted, planarizing, flattening, or tapping (e.g., tapping) pressures or forces to portions of the wafer 10 supported by the wafer table surface 622 that are unable to align to establish a secure, sufficient, or appropriate vacuum bond due to wafer non-planarity or warping. In several embodiments, in response to an indication or determination (e.g., an automatic determination performed upon execution of program instructions) that activation of one or more vacuum elements (e.g., vacuum valves) does not result in firm or sufficient vacuum engagement of the wafer 10 to the wafer table surface 622, the MFH apparatus 300 can dispose the plurality of capture arms 310 on various portions of the wafer 10 such that at least a portion of the tip element 316 of each capture arm is positioned directly over or can engage or contact a portion of the exposed, upper or top surface of the wafer 10 under consideration.

Fig. 14A-14B are schematic views of an MFH apparatus positioning capture arm tip element 316 over portions of wafer 10 to facilitate securely capturing wafer 10 on wafer table surface 622, according to an embodiment of the present disclosure. For the wafer 10 under consideration, the capture arm tip elements are positioned in such a wayThe members 316 can position each tip element 316 near or adjacent to and/or overlapping the outer periphery or outer boundary of the wafer 10. For example, each capture arm 310 within the plurality of capture arms 310 can be positioned off of the pick-and-place Z-axis Z_ppAt a radial distance approximately equal to but slightly less than the spatial extent, span or diameter of the wafer 10 under consideration. In various embodiments, the apparatus 300 can arrange the plurality of capture arms 310 such that (a) a circle intersecting a center or centroid point of the end portion 314 of each capture arm is concentric or substantially concentric with a circular or substantially circular outer boundary of the wafer 10, and (b) the tip element 316 of each capture arm can directly contact a peripheral portion of the exposed, upper or top surface of the wafer 10.

The positioning of the plurality of capture arms 310 over the exposed portions of the wafer 10 can define an engagement assist feature for the capture arms 310 and/or their corresponding tip elements 316, according to which the MFH apparatus 300 can apply an engagement assist force or pressure (e.g., a downward force or pressure) to a particular area or point of the wafer simultaneously with the wafer table assembly applying a vacuum force to the underside of the wafer 10, thereby facilitating or enabling secure capture of the wafer 10 to the wafer table surface 622. One or more engagement aid configurations defining the spatial position of the capture arm 310 corresponding to a particular or different wafer size, or diameter can be predetermined (e.g., according to a standard wafer size) and stored in and retrieved from memory.

After positioning (e.g., according to a particular bonding assistance configuration) of the plurality of capture arm tip elements 316 over exposed, upper or top portions (e.g., peripheral or outermost portions) of the wafer 10, the MFH apparatus 300 can position the capture arm tip elements 316 parallel to the pick-and-place Z-axis Z_ppAnd the Z-axis Z of the wafer table_wtIs displaced in a vertical direction toward the surface 624 of the wafer 620 (e.g., by displacing the housing 302). The tip element 316 can thus establish contact with a particular area or point on the wafer or membrane frame surface and apply a bond assist, flattening, or planarizing force (e.g., a downward force or pressure) on portions of the wafer 10. Wafer table assembly620 applies a vacuum force to the underside of the wafer 10 simultaneously with the MFH apparatus applying the bonding assist force to the wafer 10.

As (a) bonding assist force to portions of the top surface of the wafer 10; and (b) as a result of the simultaneous application of vacuum force to the underside of the wafer 10, the non-planar or warped wafer 10 can be automatically securely captured and then held on the wafer table surface 622. The secure capture of the wafer 10 on the wafer table surface 622 can be automatically indicated or determined by comparing the current vacuum pressure readings, measurements or values with the vacuum bond pressure threshold in a manner understood by those skilled in the art. After securely holding the wafer 10 on the wafer table surface 622, the MFH apparatus 300 can vertically displace the plurality of capture arms 310 away from the wafer 10, for example, by lifting or returning the housing 302 to a predetermined, default or waiting/standby position.

The above-described wafer handling process is particularly suitable for a wafer table 620 having a wafer table structure 5 according to embodiments of the present disclosure, since the presence of the ridges 120 in such a wafer table structure 5 enables the vacuum force to be confined and enclosed under the portion of the wafer table surface area covered by the wafer 10. This effective vacuum tube enclosure prevents vacuum loss and results in a strong vacuum force being applied to or to the underside of the wafer 10 in addition to the natural suction force used to hold the wafer 10 in its original position on the wafer table surface 622. Without the ridges 120, it is not possible to activate any significant vacuum force since a significant portion of the applied vacuum force would be lost through the wafer table surface area not covered by the wafer 10.

In view of the foregoing, embodiments in accordance with the present disclosure can significantly increase the likelihood that a non-planar or warped wafer 10 can be automatically captured and securely held on the wafer table surface 622. Embodiments according to the present disclosure thus significantly reduce or substantially eliminate the need for manual intervention associated with prior art systems.

Aspects of representative lateral wafer shift control/prevention

As described in detail below, when handling very thin wafers 10 with the aid of a porous wafer table, short or very short blows, air flows are applied to the wafer 10 to facilitate release of the wafer 10 from the wafer table surface. This can float the wafer 10 and cause unwanted, uncontrolled or unpredictable lateral displacement of the wafer 10 on the wafer table surface 622. Such lateral displacement can readily displace the wafer 10 away (e.g., significantly away) from a predetermined wafer load/unload position where it is desired to have the end effector 270 handle the wafer. This can lead to unreliable or unpredictable access of the wafer 10 by the end effector 270, which can further prevent the end effector from safely and reliably inserting the wafer 10 into a cassette or positioning the wafer 10 at a subsequent processing station, possibly resulting in wafer damage or breakage.

In the past, when the wafer was thick (e.g., in a normal (normal basis) direction relative to its surface area), pop-pins could be used to push the wafer from beneath it to lift it against suction, particularly if a groove was also present on the wafer table. However, if no grooves are present, the natural suction on the wafer 10 can be very strong except for residual vacuum that may remain from the application of vacuum force through the wafer table 620. This means that the vacuum below the wafer 10 is difficult to dissipate. Furthermore, today, the processed wafers 10 are much thinner. With these new constraints, it is not possible to simply use pop-pins to push thin wafers 10 held down by suction. Doing so would risk breaking the thin and brittle wafer 10.

Porous wafer tables have been used in the past in back-thinning systems/processes, but not in inspection systems/processes, up to inspection systems such as described in the following singapore patent applications: singapore patent application No.201103425-3, entitled "System and Method for Handling and aligning component Wafers as Film Frames and Wafers", filed 5, 12.2011 includes a porous wafer table 620 that can be used to handle Wafers 10. However, it has been found that releasing a very thin or ultra-thin wafer 10 from a very flat or ultra-flat porous wafer table surface 622 in a manner that reliably avoids damaging the thin and brittle wafer 10 during subsequent wafer handling can require manual intervention.

The description herein provides a solution to this problem. To facilitate the release of a very thin wafer 10 from a very flat or ultra-flat porous wafer table surface 622 in a manner that reliably avoids damage to the thin and fragile wafer 10, a momentarily positive gas pressure is applied to the underside of the wafer 10 through the porous cell material in the wafer table 620. The application of positive air pressure relieves the natural suction and reverses any residual vacuum force beneath the wafer 10. Once air is introduced below the surface of the wafer 10, the atmospheric pressure difference between the top and bottom surfaces of the wafer 10 will become equal. However, this creates an additional unique problem with wafer handling, namely the creation of a gas cushion beneath the wafer 10, which causes the levitated wafer 10 to have unintended and unpredictable lateral movement relative to the wafer table surface 622, since the gas cushion may not be uniformly distributed beneath the wafer 10. The thinner the wafer 10 being handled, the more significant the effect of the gas cushion.

Fig. 15A is a schematic view of a representative wafer 10 held uniformly relative to the vacuum chuck surface 40 by means of the natural suction force described above and the vacuum force or negative pressure applied to the underside of the wafer 10. Figure 15B is a schematic view of the wafer 10 of figure 15A after the vacuum force is stopped and a blow gas is applied to the underside of the wafer 10, which results in the creation of a gas cushion 42 beneath the wafer 10. The presence of the gas cushion 42 beneath the wafer 10 can cause the wafer 10 to slide laterally and unpredictably along the wafer table surface 622 in accordance with different support and/or wafer weight distributions provided to the wafer 10 by the underlying gas cushion 42. Fig. 15C is a schematic view of the wafer 10 of fig. 15B illustrating an unexpected or unpredictable lateral displacement ax of the wafer 10 along the wafer table surface 622 due to the gas cushion 42.

Fig. 15D-15E are schematic diagrams of an MFH apparatus positioning the capture arm 310 and capture arm tip 316 relative to the wafer 10 in a manner that limits or constrains wafer displacement along the wafer table surface 622, in accordance with an embodiment of the present disclosure. In several embodiments, after a wafer inspection operation, the MFH apparatus 300 is configured to selectively arrange the plurality of capture arms 310, thereby positioning the capture arms 310 and/or the capture arm tip elements 316 according to a constraint configuration in which the tip elements 316 are arranged relative to each other in the following manner: a planar spatial constraint zone is defined just minimally larger than the surface area of the wafer 10 on the wafer table surface 622 in order to prevent any lateral movement. No constraints are imposed on the vertical movement.

When the plurality of capture arm tip elements 316 are arranged (a) according to a constraint configuration corresponding to a wafer 10 having a given surface area a and thickness t, and (b) contact the wafer table surface 622, or are positioned at a distance from the wafer table surface 622 that is substantially less than the wafer thickness t, each tip element 316 can be located just outside the periphery of the wafer 10 and outside the wafer surface area a. Such positioning of the tip element relative to the wafer 10 and the wafer table surface 622 can prevent or limit lateral displacement of the wafer 10 along the wafer table surface 622 laterally beyond the spatially constrained region. A plurality of constraint constructs can be defined and stored in and retrieved from memory. Each constraint configuration corresponds to a particular size, dimension, area, or diameter.

As a representative example, for a given surface area A_wAnd diameter D_wFor a circular or substantially circular wafer 10, the tip constraint configuration can define or establish a Z-axis Z of pick-and-place of the tip elements 316 relative to one another_ppAnd a wafer surface area A_wOr diameter D_wSo that (a) is closest to Z_ppAnd (b) a circle that is concentric or substantially concentric with wafer 10 and slightly, very slightly, or minimally larger than wafer 10 defines a spatially-constrained region a_cAnd a corresponding spatially constrained diameter D_cWherein A is_cSlightly, very slightly or minimally greater than A_wAnd D is_cSlightly, very slightly or minimally larger thanD_w. Before the vacuum force or suction on the wafer 10 is discontinued or stopped, the MFH apparatus 300 can position the tip elements 316 according to a constraint configuration such that each tip element 316(a) slightly, very slightly, or minimally exceeds the wafer surface area Aw and (b) contacts the wafer table surface 622 or slightly, very slightly, or minimally leaves the wafer table surface 622. After the vacuum force applied to the underside of the wafer 10 is discontinued or stopped, the wafer 10 will be unreliable or very likely to move beyond or beyond Ac even during or after the blow gas is applied or delivered to the underside of the wafer 10.

After the vacuum force ceases or is interrupted and the application of the associated blow air (e.g., almost or substantially immediately after the vacuum force ceases), the capture arm tip element 316 remains briefly in the restraining configuration, positioned on or adjacent to the wafer table surface 622 to ensure restraint or prevent lateral displacement of the wafer 10. After a predetermined time delay (e.g., about 50 milliseconds to 250 milliseconds or more) and/or until the pop-pin 612 is activated to lift the wafer off the wafer table surface 622, the capture arm tip element 316 can be configured, for example, by the housing 302 along the pick-and-place Z-axis Z_ppRises off the wafer table surface 622.

Once the pop-pins 612 have lifted the wafer 10 to a final vertical position relative to the wafer table surface 622, the first handling subsystem 250 is able to capture and transport or acquire the wafer 10 to the wafer destination 240. More specifically, the end effector 260 positioned relative to the reference wafer load/unload position is able to reliably capture the wafer 10 supported by the pop-pins 612, reliably transport the wafer 10 to the next wafer destination 230 (e.g., a cassette), and reliably position the wafer 10 relative to the wafer destination 230 (e.g., within the cassette) with minimal, negligible, or substantially no risk of wafer breakage due to misalignment of the wafer relative to/on the end effector 260.

This process is particularly suitable where the wafer handling system processes very thin wafers 10 to constrain the wafers 10 to their original placement position, since very thin wafers are susceptible to unpredictable movement if positive air pressure is applied thereunder.

In an alternative embodiment, lateral wafer shift control or prevention is performed by a precisely timed wafer release and vertical wafer shift process or sequence involving (a) the wafer table assembly stopping the application of vacuum force to the backside of the wafer 10; (b) a blow is applied to the back side of the wafer; and (c) activating or extending a set of pop-pins 612 to lift or lift the wafer off the wafer table surface 622 in a manner that is precisely timed with respect to the application or initiation of the blow.

Fig. 16 is a flow diagram of a process 700 for limiting, controlling, or preventing unintended, unpredictable, or uncontrolled displacement of a wafer along a wafer table surface 622 in accordance with an embodiment of the present disclosure. In an embodiment, the wafer lift process 700 includes a first processing portion 702 that involves positioning the wafer table 620 in a predetermined, reference or default wafer load/unload position after completion of a wafer inspection operation during which the wafer table assembly 610 applies a vacuum force to the backside of the wafer 10 in order to securely hold the wafer 10 on the wafer table surface 622.

The process 700 additionally includes a second processing portion 704 that involves the wafer table assembly ceasing to apply vacuum force to the backside of the wafer 10, and immediately, substantially immediately or nearly immediately following a third processing portion 706 that involves the wafer table assembly applying a blow gas to the backside of the wafer from a blow start time to a blow stop time (the difference of which can define a blow duration). The duration of the insufflation can be, for example, about 500 milliseconds or less (e.g., about less than or equal to 250 milliseconds). As a result of the application of the blow to the backside of the wafer 10, the residual vacuum force on the backside of the wafer that may hold the wafer 10 against the wafer table top 622 is released and the natural suction on the wafer is also released.

The process 700 further includes a fourth process portion 708 that involves after the start of the blow and parallel to the wafer tableZ axis Z_wtWaits for a very short pop-pin activation delay time before activating or displacing the pop-pin 612 in the upward or vertical direction. The pop-pin activation delay time is typically very short. For example, the pop-pin activation delay time can be between about 5 milliseconds and 50 milliseconds (e.g., between about 10 milliseconds and 25 milliseconds) after the blow-on time or have a suitable time delay that can be experimentally determined. Immediately or substantially immediately after the pop-pin activation delay time has elapsed, the fifth processing portion 710 involves activating or raising the pop-pins 612 upward to lift the wafer 10 off the wafer table surface 600, and the sixth processing portion 712 involves lifting the wafer off the wafer table surface 622 with minimal or negligible lateral displacement due to the very short pop-pin activation delay time relative to the blow start time (i.e., the time at which the blow is initially applied to the back side of the wafer). Finally, the seventh processing portion 714 involves reliably acquiring the wafer 10 from the ejector pins 612 using the end effector 270.

As a result of precise or highly controlled pop pin activation times relative to the blow start time, the pop pins contact the backside of the wafer 10 for an initial portion of the blow duration and lift or raise the wafer 10 off the wafer table surface 622 substantially immediately following or substantially simultaneously with the release of the wafer 10 from the wafer table surface 622 in response to the blow. Since the pop-pins are activated or raised and engaged with the backside of the wafer 10 after a very short and well controlled, predictable or precisely timed interval after the blow start time, it is expected that any lateral movement of the wafer 10 that occurs before the pop-pins 612 lift the wafer 10 off of the wafer table surface 622 will be acceptably minimal, minimal or negligible. In a manner similar or identical to that described above, the end effector 260, which is positioned relative to the reference wafer load/unload position, can reliably capture the wafer 10 supported by the pop-pins 612, reliably transport the wafer 10 to the next wafer destination 230, and reliably position the wafer 10 relative to the wafer destination 230 with minimal, negligible, or substantially no risk of wafer breakage due to misalignment of the wafer relative to the end effector 260.

In certain embodiments, wafers 10 of different sizes, areas, or diameters can exhibit different expected optimal pop-pin activation delay times. Such different predicted optimal pop-pin activation delay times corresponding to different wafer sizes can be determined based on experimental or historical results and stored in memory or on a computer readable medium for automatic retrieval by the control unit 1000 to select an appropriate pop-pin activation delay time according to the current size of the inspected wafer.

Aspects of a representative wafer handling process

Fig. 17 is a flow diagram of a representative wafer handling process 800 according to an embodiment of the disclosure. The wafer handling process 800 can be managed or controlled by a controller or control unit 1000 (e.g., a computer system, computing device, or embedded system) by means of program instructions (e.g., stored on a computer readable medium such as fixed or removable RAM or ROM, hard disk drive, optical disk drive, etc.). Such execution of stored program instructions can include a determination of whether the wafer 10 is securely held on the wafer table surface 622 and retrieving the vacuum force engagement threshold and possibly also the constraint capture configuration parameters from memory or a computer readable medium or data storage medium.

In an embodiment, the wafer handling process 800 includes a first process portion 802 that involves taking a wafer 10 from a wafer cassette using an end effector 270; a second processing portion 804, which involves pre-aligning the wafer 10; and a third processing portion 806 which involves transferring the wafer 10 to the wafer table 620 while the wafer table 620 is positioned at the reference wafer load/unload position. The fourth processing portion 808 involves applying a vacuum force to the backside of the wafer 10, and the fifth processing portion 810 involves determining whether the wafer table 620 has established a secure hold of the wafer 10. Such a determination can include comparing a current vacuum or suction reading or vacuum or suction leak reading to a threshold vacuum force engagement value in a manner understood by those skilled in the art.

If a secure retention of wafer table 620 to wafer 10 has not been established for a given amount of time (e.g., about 0.5 to 2.0 seconds), sixth processing portion 812 involves positioning MFH apparatus capture arm tip element 316 on a peripheral portion of wafer 10 while wafer 10 remains on wafer table surface 622, and seventh processing portion 814 involves applying a downward force on such peripheral portion of wafer 10 using MFH apparatus 300 while wafer table 620 continues to apply a vacuum force to the backside of wafer 10, thereby establishing a secure capture or retention of wafer 10 on wafer table 620. In certain embodiments, the processing portions 810, 812, and 814 can be repeated multiple times (possibly with different rotational orientations of the capture arm tip element 316) without first attempting to establish a secure hold of the wafer 10 on the wafer table surface 622. As will be understood by those skilled in the art, establishment of a secure hold of the wafer 10 on the wafer table surface 622 associated with the sixth and seventh processing portions 812 can be determined by an automatic comparison of the current vacuum force reading or the vacuum force leak reading to a threshold vacuum force engagement value.

Following the seventh processing portion 814, or following the fifth processing portion 810 where a secure vacuum bond of the wafer 10 on the wafer table surface 622 occurs without the assistance of an MFH apparatus, the eighth processing portion 816 involves inspecting the wafer 10. Once the wafer inspection is complete, the ninth processing portion 818 involves positioning the wafer table 620 at a wafer load/unload position.

The tenth processing portion 80 involves determining whether unwanted lateral displacement of the wafer 10 is limited or prevented using the MFH apparatus 300. If so, the eleventh processing portion 822 involves positioning the MFH apparatus capture arm tip element 316 in an appropriate wafer restraint configuration with respect to the diameter of the wafer, and the twelfth processing portion 824 involves disposing the restraining configured tip element 316 on the wafer table surface 622 such that the wafer periphery is at a capture restraint area A defined by the restraint configuration_CAnd (4) the following steps. The thirteenth processing portion 626 involves terminating the wafer table applying vacuum force to the backside of the wafer 10 and applying a blow gas to the waferAnd the fourteenth processing portion 628 involves retaining the capture arm tip element 316 in the constraint configuration on the wafer table surface 622 until the raised eject pin 612 has engaged the wafer 10 to lift the wafer 10 off the wafer table surface 622 while the capture arm tip element 316 remains in the constraint configuration and contacts the wafer table surface 316, preventing the wafer 10 from exceeding the constraint area a_CThereby ensuring that the wafer 10 remains at or about the predetermined wafer capture position for subsequent reliable, non-destructive wafer handling by the end effector 270.

Once the pop-pins 612 have begun to lift the wafer 10 off of the wafer table surface 622, the fifteenth processing portion 830 involves moving the MFH apparatus 300 off of the wafer table 620 (e.g., by vertically displacing the MFH apparatus housing 302); and the final processing portion 840 involves taking the wafer 10 from the ejector pin 612 and returning the wafer to the cassette using the end effector 270.

Aspects of a representative film frame handling process

Fig. 18 is a flow diagram of a representative film frame handling process 900 according to an embodiment of the present disclosure. In a manner similar to that described above, the film frame handling process 900 can be managed or controlled by the control unit 1000 by means of program instructions (e.g., stored on a computer-readable medium such as fixed or removable Random Access Memory (RAM), Read Only Memory (ROM), a hard disk drive, an optical disk drive, etc.). Such execution of the stored program instructions can include retrieving from memory a maximum wafer relative to the film frame misalignment threshold; determining whether a degree or magnitude of misalignment of the wafer relative to the film frame is less than or greater than a maximum misalignment threshold; and retrieving from memory a set of MFH device capture arm positions corresponding to the considered diaphragm rack size.

In an embodiment, the film frame handling process 900 includes a first process portion 902 that involves acquiring a film frame 30 from a film frame cassette using an end effector 270, the end effector 270 applying a vacuum force to a peripheral portion of the underside, back side, or bottom surface of the film frame. Some embodiments of the film frame handling process 900 can include a second process portion 904 that involves a mechanical film frame registration process in which film frame alignment features are matingly engaged with a set of film frame registration elements 282. For example, registration element 282 can be carried by end effector 270, a portion of MFH apparatus 300, a portion of misalignment inspection system 500, or a portion of wafer table 620.

As described above, in various embodiments, such mechanical film frame registration processes can be avoided, omitted, eliminated, or eliminated (considering film frame registration processes based on optical or image processing), thereby avoiding or eliminating conventional film frame handling events or processes, saving time and increasing throughput. Thus, depending on the details of the embodiment, the second processing portion 904 can be omitted or eliminated, or the second processing portion 904 can be optional in view of the optical film frame registration process performed by means of the misalignment inspection system 500 and the MFH apparatus 300.

The third processing portion 906 involves determining the rotational or angular direction and magnitude of the misalignment of the wafer relative to the film frame 30 using the misalignment inspection system 500. As described above, according to implementation details, the determination of the angle of misalignment of the wafer relative to the film frame 30 can be performed (a) outside of the system 200 or remotely prior to the acquisition of the film frame 30 by the end effector 270 in relation to the first processing portion 902; or (b) at any time after the film frame 30 is acquired by the end effector 270 but before the inspection system 600 begins the film frame inspection.

The fourth process portion 908 involves positioning the membrane holder 30 under the MFH apparatus 300, e.g., such that the MFH apparatus captures a common axis of arm rotation (e.g., accessing the Z-axis Z)_pp) Coinciding with or extending through the center or approximate center of the diaphragm frame 30. The fifth processing portion 910 involves positioning the MFH device capture arm tip element 316 over a peripheral portion of the upper or top surface of the film frame and applying a vacuum force through the capture arm 310 so that the MFH device 300 securely captures the film frame 30. The sixth processing section 912 involves terminating or relieving the vacuum force applied by the end effector to the peripheral portion of the underside of the film frame, andthe end effector 270 is moved away from the MFH apparatus 300.

The seventh processing portion 914 involves rotating the film frame 30 using the MFH apparatus (e.g., by simultaneously rotating the capture arm 310 about the common axis of capture arm rotation described above) in the event that the wafer misalignment relative to the film frame determined in association with the third processing portion 906 exceeds a maximum misalignment threshold or in the event that misalignment of the wafer relative to the film frame is detected or determined. Such rotation is performed in a direction and angle for correcting misalignment of the wafer with respect to the film frame (i.e., opposite to the misalignment of the wafer with respect to the film frame).

The eighth processing section 916 involves moving the wafer table 620 to a film frame loading/unloading position, which can be done simultaneously with the seventh processing section 914, thereby saving time and increasing throughput. The ninth processing portion 918 involves placing the film frame 30 on the wafer table 620 using the MFH apparatus 300, for example, by means of vertical displacement of the MFH apparatus housing 302. The ninth processing portion 918 can involve displacing the MFH apparatus housing 302 a predetermined distance and/or a determination of whether the film frame 30 is securely captured by the wafer table 620 in association with the tenth processing portion 920 that involves applying a vacuum force to the underside of the film frame 30 using the wafer table 620. Once the film frame 30 has been securely captured by wafer table 620, the tenth processing portion 920 further involves terminating the application of vacuum force applied to the top surface of film frame 30 by capture arm 310 and moving MFH apparatus 300 away from wafer table 620, thereby enabling subsequent film frame inspection. In particular embodiments, the ninth processing portion 918 can additionally or alternatively involve displacing the housing 302 toward the wafer table surface 622 until the capture arm tip element 316 contacts the wafer table surface 622, which can be determined by means of a set of sensors (e.g., optical sensors).

The eleventh processing section 922 involves inspecting the film frame 30 and the twelfth processing section 924 involves positioning the wafer table 620 in a film frame load/unload position. The thirteenth process portion 926 involves positioning the MFH apparatus capture arm tip element 316 on a peripheral portion of the top side of the film frame and applying a vacuum force to the top side of the film frame 30 to capture the film frame 30 with the film frame 30 held (e.g., securely held) on the wafer table surface 622. The fourteenth processing section 928 involves interrupting the application of vacuum force by the wafer table to the underside of the film frame so that the MFH apparatus can capture and remove the film frame 30 from the wafer table 620.

A fifteenth processing section 930 involves moving MFH apparatus 300, which securely holds film frame 30, away from wafer table surface 622, for example, by vertically displacing MFH apparatus housing 302. A sixteenth processing section 932 involves positioning the end effector 270 under the MFH apparatus 300, and a seventeenth processing section 934 involves capturing portions of the backside periphery of the membrane holder with the end effector 270 by means of a vacuum force applied through the end effector 270, such that the membrane holder 30 is securely held by the end effector 270 (and simultaneously by the MFH apparatus 300). The eighteenth processing section 936 is concerned with interrupting the vacuum force applied by the MFH apparatus 300 to the peripheral portion of the membrane holder so that the membrane holder 30 is released from the MFH apparatus 300. Finally, the nineteenth processing section 938 involves lowering the end effector 270 relative to the MFH apparatus 300 and transporting the film frame 30 back to the film frame cassette using the end effector 270.

Aspects according to various embodiments of the present disclosure address at least one aspect, problem, limitation, and/or disadvantage associated with existing systems and methods for handling wafers and/or film frames. Aspects in accordance with various embodiments of the present disclosure address each of the problems, limitations, and/or disadvantages described above with regard to existing systems and methods for handling wafers and/or film frames. Furthermore, embodiments according to the present disclosure improve wafer and/or film frame handling in a manner that prior art systems and methods do not or cannot achieve by eliminating specific handling events or processes, which enables enhanced throughput. While features, aspects, and/or advantages associated with certain embodiments have been described in the present disclosure, other embodiments may also exhibit such features, aspects, and/or advantages, and not all embodiments need necessarily exhibit such features, aspects, and/or advantages to fall within the scope of the present disclosure. Those skilled in the art will appreciate that some of the above disclosed systems, components, processes, or alternatives thereof can be combined with other different systems, components, processes, and/or applications as desired. In addition, various modifications, alterations, and/or improvements to the various embodiments disclosed may occur to those skilled in the art within the scope of the disclosure.

Claims (23)

1. A system for handling wafers mounted on film frames, the system comprising:

a wafer table providing a wafer table surface configured to securely hold a film frame thereon;

a wafer inspection system having a first image capture device configured to perform an inspection process on a wafer mounted on a film frame and held by the wafer table surface;

a second image capture device configured to capture at least one image of portions of a wafer mounted on the film frame;

a processing unit configured to analyze the at least one image of portions of the wafer mounted on the film frame by executing program instructions that perform image processing operations on the at least one image to determine a rotational misalignment angle and a rotational misalignment direction of the wafer relative to a field of view of the film frame or the first or second image capture devices; and

a film frame handling apparatus configured to transfer a film frame on which the wafer is mounted to the wafer table surface,

wherein determining the rotational misalignment angle and the rotational misalignment direction of the wafer comprises analyzing a plurality of first and second linear features present on the wafer, the first and second linear features being perpendicular to each other,

wherein the film frame handling apparatus is further configured to rotate the film frame to correct any rotational misalignment of the wafer relative to the film frame, the first image capture device, and/or the second image capture device.

2. The system of claim 1, wherein the film frame handling apparatus is configured to rotate the film frame in a direction opposite the rotational misalignment direction by an angular magnitude corresponding to the rotational misalignment angle, wherein the wafer inspection system is configured to begin the inspection process without requiring a mechanical film frame registration process involving establishing mating engagement of film frame alignment features with a set of registration elements, and wherein correction for rotational misalignment of the wafer is performed without reducing film frame handling throughput or inspection process throughput.

3. The system of claim 1, wherein the first image capture device is separate from the second image capture device.

4. The system of claim 3, wherein the second image capture device is configured to capture at least one image of portions of the wafer on the film frame prior to placement of the film frame on the wafer table surface.

5. The system of claim 4, wherein the second image capture device is configured to capture at least one image of portions of the wafer on the film frame while the film frame is in motion.

6. The system of claim 1, wherein the first image capture device and the second image capture device form portions of the wafer inspection system.

7. The system of claim 5, wherein the image processing operation is configured to identify at least one of:

one or more wafer structural and/or visual features including a wafer flat and a set of wafer gridlines, an

One or more film frame structural and/or visual features including a film frame flat.

8. The system of claim 1, wherein the time required to transfer the film frame through the film frame handling apparatus to the wafer table surface corresponds to the time taken when the rotational misalignment angle is zero, regardless of the time taken to correct the rotational misalignment of the wafer.

9. The system of claim 1, wherein the film frame handling apparatus is configured to correct the rotational misalignment of the wafer relative to the film frame only when the rotational misalignment of the wafer exceeds a programmable or predetermined misalignment angle threshold.

10. The system of claim 1, wherein the film frame handling apparatus comprises:

a main body;

a plurality of vacuum elements coupled to the body and configured to engage portions of a boundary of the film frame by way of negative pressure, the plurality of vacuum elements being controllably movable to a plurality of different positions transversely relative to a common axis corresponding to a center of the film frame in a direction toward and away from the common axis;

a capture positioning assembly for positioning the plurality of vacuum elements at each different location to facilitate engagement of the plurality of vacuum elements with a film frame boundary; and

a rotational misalignment compensation motor configured to selectively and simultaneously rotate the plurality of vacuum elements in a common direction about the common axis so as to accurately correct rotational misalignment of the wafer relative to the film frame,

wherein each different position corresponds to a different membrane frame size.

11. The system of claim 10, wherein the film frame handling apparatus further comprises a plurality of displaceable capture arms carrying the plurality of vacuum elements and coupled to the body.

12. The system of claim 11, further comprising a vertical displacement drive configured to controllably displace the plurality of displaceable capture arms along a vertical direction perpendicular to the wafer table surface.

13. The system of claim 12, wherein the film frame handling apparatus is configured to place the film frame directly on the wafer table surface.

14. A method for handling a wafer mounted on a film frame, the method comprising:

providing a wafer table surface configured to securely hold a film frame thereon;

capturing at least one image of a wafer mounted on a film frame using an image capture device prior to initiation of an inspection process of the wafer by a wafer inspection system;

analyzing the at least one image by means of an image processing operation to determine a rotational misalignment angle and a rotational misalignment direction of the wafer relative to a set of reference axes of a field of view of the film frame and/or the image capture device;

correcting rotational misalignment of the wafer relative to the set of reference axes of the film frame and/or the field of view of the image capture device by means of a film frame handling apparatus separate from the inspection system,

wherein determining the rotational misalignment angle and the rotational misalignment direction of the wafer comprises analyzing a plurality of first and second linear features present on the wafer, the first and second linear features being perpendicular to each other.

15. The method of claim 14, wherein the correcting for the rotational misalignment of the wafer comprises rotating the film frame an angular magnitude corresponding to the rotational misalignment angle in a direction opposite the rotational misalignment direction, wherein a mechanical film frame registration process is avoided prior to initiating an inspection process in which a set of film frame structural features are aligned relative to a corresponding set of registration elements configured to matingly engage with the set of film frame structural features.

16. The method of claim 14, wherein the time required to transfer the film frame through the film frame handling apparatus to the wafer table surface corresponds to the time taken when the rotational misalignment angle is zero, regardless of the time taken to correct the rotational misalignment of the wafer.

17. The method of claim 14, wherein the capturing of the at least one image occurs while the film frame is in motion during the transporting of the film frame to the wafer table surface.

18. The method of claim 14, wherein the capturing of the at least one image occurs after the film frame has been transferred to the wafer table surface.

19. The method of claim 18, wherein the inspection system is an optical inspection system and the capturing of the at least one image is performed by means of an image capturing device of the optical inspection system.

20. The method of claim 14, wherein determining the rotational misalignment angle and the rotational misalignment direction comprises: (i) performing an image processing operation on the at least one image to detect one or more wafer structures and/or visual features relative to an orientation of one or more film frame structures and/or visual features or spatial directions associated with such film frame structures and/or visual features, or (ii) relative to an orientation of the set of reference axes of the field of view of the image capture device.

21. The method of claim 20, wherein the wafer structural and/or visual features comprise at least one of a wafer flat, a set of wafer gridlines, and a film frame flat.

22. The method of claim 14, wherein compensating or correcting for the rotational misalignment of the wafer relative to the film frame is performed only when the rotational misalignment of the wafer relative to the film frame exceeds a programmable or predetermined misalignment angle threshold.

23. The method of claim 16, wherein transferring the film frame to the wafer table surface comprises placing the film frame directly on the wafer table surface.