TWI830410B - Semiconductor process equipment and wafer condition monitoring method - Google Patents

Abstract

A semiconductor process equipment includes a process chamber, a controller and a bearing disc arranged in the process chamber. The bearing disc is provided with a wafer lifting mechanism for supporting wafers, and the top of the process chamber is provided with a plurality of distance monitoring devices for monitoring the distance between itself and a plurality of different positions on the bearing disc. The controller is used to obtain the monitoring results of multiple distance monitoring devices in real time during the wafer lifting action of the wafer lifting mechanism, and determine the abnormal state of the wafer when the monitoring results of multiple distance monitoring devices are inconsistent.

Description

Semiconductor process equipment and wafer status monitoring method

The present invention relates to the field of semiconductor processing equipment, and specifically, to a wafer status monitoring method and a semiconductor processing equipment capable of implementing the method.

In the integrated circuit chip manufacturing industry, the process of processing wafers generally includes photolithography, etching, ion implantation, metal deposition, core packaging and other processes. Among them, the plasma etching process uses an etching machine to accurately transfer photoresist patterns such as lines, surfaces or holes to the material underneath the photoresist through the photolithography process to form the complex structure that the entire integrated circuit should have; The packaging process is to thin the device wafer as a whole before back packaging, which also requires a plasma etching process.

In the plasma etching process, it is usually necessary to place the wafer on an electrostatic chuck (ESC) in the process chamber of the semiconductor processing equipment, and then process the wafer. During the processing, the electrostatic chuck plays a role. It supports and fixes the wafer, and controls the temperature of the wafer during the manufacturing process. The electrostatic chuck uses electrostatic force to fix the wafer, which can effectively avoid the shortcomings of the mechanical chuck such as complex structure and reduced effective processing area of the wafer.

However, in the solution of using an electrostatic chuck to fix the wafer, the Dechuck step (the step of unloading the electrostatic attraction force of the electrostatic chuck on the wafer and removing the wafer from the electrostatic chuck) Abnormal wafer status often occurs. After the semiconductor process is completed, there is often residual charge on the electrostatic chuck, resulting in an electrostatic adsorption force still existing between the wafer and the electrostatic chuck, making it impossible to completely release the wafer. At this time, the ejector pin jacking up the wafer is very likely to cause the wafer to break, or the wafer is tilted after the ejector pin jacks up the wafer, and the robot arm reaches into the process chamber and performs the wafer transfer action. A collision occurs, causing damage to the wafer. Not only does it take a lot of time to clean the process chamber after the wafer is broken, but the chamber contamination caused by the wafer breakage may also affect the cleanliness inside the process chamber in subsequent semiconductor manufacturing processes, thereby affecting product yield.

The present invention aims to provide a wafer status monitoring method and a semiconductor processing equipment that can implement the method. The wafer status monitoring method can timely detect abnormal wafer status problems and improve the safety of the wafer.

In order to achieve the above object, as an aspect of the present invention, a semiconductor processing equipment is provided, which includes a process chamber and a carrier tray disposed in the process chamber. The carrier tray is used to carry wafers. The carrier tray is provided with a wafer. A circular lifting mechanism is used to lift the wafer. A plurality of distance monitoring devices are provided on the top of the process chamber. The plurality of distance monitoring devices are used to respectively monitor the distance between itself and multiple different positions on the carrier plate. distance; the semiconductor process equipment also includes: a controller, used to instantly obtain the monitoring results of multiple distance monitoring devices during the lifting action of the wafer lifting mechanism, and determine the monitoring results of multiple distance monitoring devices Whether the results are consistent, and when the monitoring results of multiple distance monitoring devices are inconsistent, it is determined that the state of the wafer is abnormal.

Optionally, a mobile recorder is also included. The mobile recorder is used to record the theoretical height of the lifting of the wafer lifting mechanism: the controller is also used to lift the wafer during the process of the wafer lifting mechanism. , instantly obtain the lifting information of the wafer lifting mechanism recorded by the mobile recorder The theoretical distance measurement value is calculated based on the theoretical height, the pre-obtained distance between the distance monitoring device and the bearing surface of the carrier plate, and the thickness of the wafer. The theoretical distance measurement value is The distance between the distance monitoring device and the bearing surface of the carrier plate is the difference obtained by subtracting the thickness of the wafer and then subtracting the theoretical height; the controller is also used to compare the theoretical distance measurement value with multiple distances According to the monitoring results of the monitoring device, when the monitoring results of multiple distance monitoring devices are consistent with the theoretical ranging value, the wafer is determined to be in a normal state; when the monitoring result of at least one distance monitoring device is greater than the theoretical ranging value , it is determined that the wafer has a sticking abnormality.

Optionally, the controller is also configured to determine that a local sticking abnormality occurs in the wafer when the monitoring results of some of the distance monitoring devices among the plurality of distance monitoring devices are greater than the theoretical distance measurement value.

Optionally, the controller is also configured to determine that a jump abnormality occurs in the wafer when the monitoring results of some of the distance monitoring devices among the plurality of distance monitoring devices are less than the theoretical distance measurement value.

Optionally, the controller is also configured to control the wafer lifting mechanism to descend to place the wafer back on the bearing surface of the bearing tray after determining that the wafer has abnormal adhesion.

Optionally, a wafer transfer structure is also included, the wafer transfer structure is used to cooperate with the wafer lifting mechanism to transfer the wafer to the carrier tray and transfer the wafer on the carrier tray out of the process chamber; The controller is also used to obtain the monitoring results of multiple distance monitoring devices and determine the monitoring results of multiple distance monitoring devices after the wafer transfer structure and the wafer lifting mechanism cooperate to transfer the wafer to the carrier tray. Whether the results are consistent, and when the monitoring results of multiple distance monitoring devices are inconsistent, it is determined that the state of the wafer is abnormal.

Optionally, the controller is also used to obtain monitoring results of a plurality of distance monitoring devices after the wafer transfer structure cooperates with the wafer lifting mechanism to transfer the wafer to the carrier tray. As a result, the initial ranging value is compared with the monitoring results of multiple distance monitoring devices. When the monitoring results of multiple distance monitoring devices are consistent with the initial ranging value, it is determined that the film transmission is abnormal, wherein the initial ranging value This is the distance between the distance monitoring device itself and the bearing surface of the bearing plate.

Optionally, the controller is also configured to compare the slide distance measurement value with the detection results of multiple distance monitoring devices when the monitoring results of multiple distance monitoring devices are inconsistent with the initial ranging value. When the detection results of the distance monitoring device are all consistent with the distance measurement value of the slide, it is determined that the film transfer is normal; when the detection results of multiple distance monitoring devices are inconsistent with the distance measurement value of the slide, it is determined that the thickness of the wafer is abnormal. Wherein, the slide distance measurement value is the difference value obtained by subtracting the thickness of the wafer from the distance between the distance monitoring device itself and the bearing surface of the bearing plate.

Optionally, there are two distance monitoring devices, and the two distance monitoring devices are symmetrical with respect to the axis of the bearing plate.

Optionally, the distance monitoring device is a distance measuring sensor.

As a second aspect of the present invention, a wafer status monitoring method is provided, which is applied to the aforementioned semiconductor processing equipment, including: during the lifting action of the wafer lifting mechanism, obtaining multiple distances in real time Monitoring results of the monitoring device; determine whether the monitoring results of multiple distance monitoring devices are consistent; if the monitoring results of multiple distance monitoring devices are inconsistent, determine that the state of the wafer is abnormal.

The wafer status monitoring method and semiconductor process equipment provided by the present invention can instantly obtain the distance monitoring results of multiple distance monitoring devices on the top of the process chamber (i.e., distance monitoring devices) during the lifting action of the wafer lifting mechanism. distance between itself and different positions on the carrier tray), so that abnormal wafer status problems (such as abnormal angle, abnormal thickness, abnormal wafer sticking, abnormal wafer jump, abnormal wafer transfer) can be discovered in time, and subsequent actions can avoid damaging the wafer. Causes further damage, improves wafer safety, reduces process chamber maintenance costs, and ensures Product yield of semiconductor manufacturing process.

1:Media window

2: Inductive coupling coil

3: Matcher

4: Up excitation RF source

5: Process chamber

6:Plasma

7:wafer

8:Thimble mechanism

9:Refrigerant gas channel

10:Electrode

11:Electrostatic chuck

12:Chuck base

13:Lower matcher

14: Down bias RF power source

15: DC power supply

16:Manipulator

100: Carrying tray

210: First ranging sensor

220: Second ranging sensor

300:Thimble structure

310:Controller

320:Motor controller

330:Motor

340:Mobile recorder

400:wafer

The present disclosure is best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be noted that in accordance with standard practice in the industry, the various components are not drawn to scale. In fact, the dimensions of the various components may be arbitrarily increased or reduced for clarity of discussion.

Figure 1 is a schematic structural diagram of a process chamber of an existing plasma processing equipment; Figure 2 is a schematic diagram of the principle of the ejection pin in the plasma processing equipment in Figure 1 driving the wafer to rise; Figure 3 is a schematic diagram of a fault in the plasma processing equipment in Figure 1 A schematic diagram of one situation; Figure 4 is a schematic diagram of another situation in which a fault occurs in the plasma processing equipment in Figure 1; Figure 5 is a schematic structural diagram of a semiconductor processing equipment provided by an embodiment of the present invention; Figure 6 is a semiconductor provided by an embodiment of the present invention. A schematic diagram of the wafer lifting mechanism driving the wafer up in the process equipment; Figure 7 is a schematic diagram of an abnormal state of the wafer in the semiconductor process equipment provided by the embodiment of the present invention; Figure 8 is the semiconductor process provided by the embodiment of the present invention A schematic diagram of another situation where the wafer status in the equipment is abnormal; Figure 9 is a schematic diagram of another situation where the wafer status is abnormal in the semiconductor processing equipment provided by an embodiment of the present invention; Figure 10 is a wafer status monitoring provided by an embodiment of the present invention A schematic flowchart of the method; Figure 11 is a partial schematic flowchart of a wafer status monitoring method provided by another embodiment of the present invention; Figure 12 is a partial schematic flowchart of a wafer status monitoring method provided by another embodiment of the present invention.

The following disclosure provides many different embodiments or examples of different means for implementing the disclosure. Specific examples of components and configurations are described below to simplify the present disclosure. Of course, these are examples only and are not intended to be limiting. For example, the following description in which a first member is formed over or on a second member may include embodiments in which the first member and the second member are formed in direct contact, and may also include embodiments in which additional members Embodiments may be formed between the first member and the second member such that the first member and the second member may not be in direct contact. Additionally, the present disclosure may repeat reference numbers and/or letters in various instances. This repetition is for simplicity and clarity and does not inherently indicate a relationship between the various embodiments and/or configurations discussed.

In addition, for ease of description, spatially relative terms such as “below,” “below,” “lower,” “above,” “upper,” and the like may be used herein to describe one element or component in relation to another(s). The relationship between components or components, as illustrated in the figure. Spatially relative terms are intended to cover different orientations of the device in use or operation other than the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the disclosure are approximations, the values stated in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Furthermore, as used herein, the term "about" generally means within 10%, 5%, 1% or 0.5% of a given value or range. Alternatively, the term "approximately" means within one acceptable standard error of the mean when considered by one of ordinary skill in the art. Except in operating/working examples, or unless otherwise expressly specified, all numerical ranges such as quantities, durations of time, temperatures, operating conditions, ratios of quantities, and the like for materials disclosed herein, number Amounts, values, and percentages should be understood to be modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the patent claims of this disclosure and accompanying invention claims are approximations that may vary as necessary. At a minimum, each numerical parameter should be interpreted in light of the number of reported significant digits and by applying ordinary rounding techniques. Ranges may be expressed herein as from one endpoint to the other endpoint or between two endpoints. All ranges disclosed herein include endpoints unless otherwise specified.

Figure 1 shows a schematic structural diagram of a process chamber of an existing plasma processing equipment. The top of the process chamber 5 is provided with a dielectric window 1. An inductive coupling coil 2 is installed above the dielectric window 1, and the upper excitation RF source 4 passes through the matcher. 3 provides a radio frequency signal to the inductive coupling coil 2 to excite the process gas in the process chamber into plasma 6 through the upper electrode composed of the upper excitation RF power source 4, the upper matcher 3 and the inductive coupling coil 2. The lower bias RF power source 14 is connected to the electrostatic chuck 11 through the lower matching device 13. The lower electrode composed of the lower bias RF power source 14, the lower matching device 13 and the electrostatic chuck 11 can generate DC self-bias on the surface of the wafer 7 Pressure is applied to attract plasma to impact the wafer 7 , thereby processing the surface of the wafer 7 .

The electrostatic chuck 11 is installed on the chuck base 12. There are electrodes 10 embedded inside the chuck. The electrodes 10 are surrounded by insulating materials. The 15 pairs of electrodes of the DC power supply load DC high-voltage static electricity, so that the 10 pairs of electrodes of the electrostatic chuck are crystallized. The circle 7 produces an adsorption effect, thereby fixing the wafer 7 on the electrostatic chuck 11 . The electrostatic chuck 11 is also provided with a refrigerant liquid channel (not shown). Constant-temperature refrigerant liquid circulates in the refrigerant liquid channel to control the temperature of the electrostatic chuck 11 and the wafer 7 . The interior of the electrostatic chuck 11 can also be provided with a refrigerant gas channel 9. The back blow air path controls the refrigerant gas with a certain pressure or flow rate to blow the back of the wafer 7 (ie, the lower surface of the wafer 7 in the figure), so that the During the manufacturing process, the temperature of the wafer 7 is controlled. The electrostatic chuck 11 fixes the wafer 7 through electrostatic force to prevent refrigerant gas from leaking from the back of the wafer 7 .

The electrostatic chuck 11 is also provided with an ejection pin mechanism 8 inside, which can be raised and lowered freely. During the manufacturing process, the ejector pin drops below the upper surface of the electrostatic chuck 11 . After the process is completed, as shown in Figure 2, the ejection pin mechanism 8 rises to lift the wafer 7 from below. The external manipulator 16 enters the process chamber and extends into the lower part of the wafer 7. The ejection pin mechanism 8 descends to the electrostatic chuck. Below the carrying surface of the tray 11, the wafer 7 is transferred to the robot arm 16, and then the robot arm 16 is retracted to transfer the wafer 7 out of the chamber.

However, since the electrostatic chuck 11 is usually made of ceramic, and the main material is aluminum oxide (Al ₂ O ₃ ), the fluorine (F)-based gas used in the manufacturing process will gradually generate fluorine with the aluminum oxide in the ceramic. chemical reaction to produce aluminum fluoride (AlF ₃ ). Aluminum fluoride materials have the property of easily absorbing negative charges. Therefore, after a long-term semiconductor manufacturing process, even if the voltage of the adsorption electrode in the electrostatic chuck 11 is turned off, the electrostatic chuck 11 still has residual negative charges, causing corresponding positive charges to be generated on the wafer. Although the amount of residual charge is not large, the distance between the carrying surface of the electrostatic chuck 11 and the wafer 7 is extremely small, so the electrostatic chuck 11 can still produce a large adsorption force on the wafer 7, thereby causing the wafer to transfer. Dechuck problem occurs during the process of exiting the chamber.

In some cases, as shown in Figure 3, due to the adsorption effect generated by the residual charge, after the electrostatic chuck is discharged, when the ejection pin mechanism 8 rises, the wafer 7 is still adsorbed by the electrostatic chuck 11, which in turn causes the ejection pin mechanism 8 to rise. When the ejection pin mechanism 8 is raised, the wafer 7 is ejected into pieces; in other cases, as shown in Figure 4, after the ejection pin mechanism 8 is raised, one side of the wafer 7 is still adsorbed to the electrostatic chuck 11, causing the wafer 7 to be tilted state, which in turn causes the robot 16 to collide with the wafer 7 after extending into the process chamber, resulting in damage to the wafer 7 .

In order to solve the above technical problems, as an aspect of the present invention, a semiconductor processing equipment is provided. As shown in FIGS. 5 to 8 , the semiconductor processing equipment includes a process chamber and a carrier tray 100 disposed in the process chamber. The carrier tray 100 is used to carry the wafer 400. The carrying tray 100 is provided with a wafer lifting mechanism (including the ejection pin structure 300 and other structures) for lifting. operation to realize lifting the wafer 400 times. A plurality of distance monitoring devices (for example, may include a first distance sensor 210 and a second distance sensor 220) are disposed on the top of the process chamber, and the multiple distance monitoring devices are used to monitor themselves and the carrier tray 100 respectively. the distance between different locations on. It is easy to understand that if the carrier tray 100 carries the wafer 400, the distance is the distance between the multiple distance monitoring devices themselves and the different positions of the wafer 400 on the carrier tray 100; if the carrier tray 100 does not carry a wafer 400, then the distance is the distance between the multiple distance monitoring devices themselves and different positions of the bearing surface of the bearing tray 100.

The semiconductor process equipment also includes: a controller 310, used to obtain monitoring results of multiple distance monitoring devices in real time during the lifting action of the wafer lifting mechanism, and determine whether the monitoring results of the multiple distance monitoring devices are consistent; And when the monitoring results of the multiple distance monitoring devices are inconsistent, it is determined that the state of the wafer 400 is abnormal.

In the semiconductor processing equipment provided by the present invention, the controller 310 can instantly obtain the distance monitoring results of multiple distance monitoring devices on the top of the process chamber during the lifting action of the wafer lifting mechanism, so that the wafer lifting mechanism can timely detect the distance monitoring results. Abnormal wafer status problems are avoided to avoid further damage to the wafer 400 caused by subsequent actions (for example, the ejection pin rises and breaks the wafer 400, when the wafer 400 is tilted, the wafer transfer structure (such as a robot) performs a pick-up action and collides with the wafer 400, etc. situation), improves the safety of the wafer 400, reduces the maintenance cost of the process chamber, and ensures the product yield of the semiconductor process.

The above-mentioned wafer status abnormality problems include, for example, abnormal angle, abnormal thickness, abnormal wafer sticking, abnormal wafer jump, abnormal wafer transfer, etc. Specifically, the wafer sticking abnormality occurs when the wafer lifting mechanism lifts the wafer 400. If the entire wafer sticks to the bearing surface of the carrier tray 100, the overall wafer sticking abnormality will occur (i.e., the situation shown in Figure 9 ); if part of the wafer is separated from the bearing surface when the wafer lifting mechanism is lifting, and the other part is still stuck to the bearing surface of the bearing tray 100, Partial adhesion abnormalities will occur. In this case, the monitoring results of multiple distance monitoring devices can be obtained instantly by lifting the wafer 400 by the wafer lifting mechanism (that is, the multiple distance monitoring devices themselves are respectively connected with the surface of the wafer 400 distances between multiple different positions) to determine whether abnormal bonding occurs. For example, during the process of lifting the wafer 400 by the wafer lifting mechanism, if the wafer is tilted due to bonding, the distance between different positions will result. If there is a difference between the monitoring results of the monitoring device, it can be determined that an abnormal sticking film has occurred.

The abnormal chip jump occurs when the wafer lifting mechanism lifts the wafer 400. If the wafer height is higher than its theoretical height (that is, the self-loading surface of the wafer rises normally when being lifted by the wafer lifting mechanism). displacement), a jump exception occurs.

The wafer transfer abnormality occurs when the wafer transfer structure and the wafer lifting mechanism cooperate to transfer the wafer 400 to the bearing surface of the carrier tray 100. If the wafer 400 does not land normally on the bearing surface of the carrier tray 100, the wafer transfer occurs. Abnormality, for example, if the monitoring results of multiple distance monitoring devices are still equal to the distance between the distance monitoring device and the bearing surface of the bearing tray 100, it means that the wafer 400 has not landed on the bearing surface of the bearing plate 100 normally, and then it can be determined that the transmission Film is abnormal.

Thickness anomalies are thickness inconsistencies at multiple different locations on the wafer surface. If the detection results of multiple distance monitoring devices are inconsistent with the carrier distance measurement value (the difference obtained by subtracting the thickness of the wafer 400 from the distance between the distance monitoring device itself and the bearing surface of the carrier tray 100), then it can be It is determined that the thickness of wafer 400 is abnormal.

Angle abnormality refers to the tilt of the wafer. If the monitoring results of multiple distance monitoring devices are inconsistent, it can be determined that the angle is abnormal.

As an optional embodiment of the present invention, the distance monitoring device may be a distance sensor, used to vertically monitor the distance between itself and the corresponding position on the surface of the wafer 400 (or the bearing surface of the carrier 100). , that is, the distance monitoring device monitors itself based on optical principles The distance from the surface of the wafer 400 (or the bearing surface of the bearing tray 100). Specifically, the distance monitoring device (periodically) emits a beam of light (for example, infrared light) vertically downward, and receives the reflected light reflected by the surface of the wafer 400 (or the bearing surface of the carrier 100). Therefore, the total distance traveled by the light can be determined based on the time elapsed between emitting the light and receiving the reflected light, and then determining the distance between itself and the surface of the wafer 400 (or the bearing surface of the carrier 100).

In order to reduce the installation cost and material cost of the distance monitoring device, as a preferred embodiment of the present invention, as shown in Figure 5, two distance monitoring devices are provided on the top of the process chamber (the distance monitoring device is a distance sensor. At this time, that is, the first distance sensor 210 and the second distance sensor 220 are provided on the top of the process chamber), and the two distance monitoring devices are symmetrical with respect to the axis of the bearing tray 100 .

In order to improve the accuracy of monitoring the status of the wafer 400 through the two distance monitoring devices, as a preferred embodiment of the present invention, as shown in Figure 5, the projection positions of the distance monitoring devices on the surface of the wafer 400 are close to the corresponding side of the wafer 400. edge, so that when the wafer angle changes by the same amount, the monitoring result of the distance monitoring device will produce a greater change, and the monitoring accuracy of monitoring the state of the wafer 400 will be improved.

As an optional embodiment of the present invention, the semiconductor processing equipment also includes a wafer transfer structure. The wafer transfer structure is used to cooperate with the wafer lifting mechanism to transport the wafer 400 on the carrier tray 100 and to transfer the wafer 400 on the carrier tray 100. Wafer 400 is transferred out of the process chamber.

It should be noted that the step of judging whether the monitoring results of the multiple distance monitoring devices are consistent (that is, judging whether the angle of the wafer 400 is abnormal) can be continuously performed in a loop throughout the semiconductor process, that is, from putting the wafer into the process chamber. During the process from inserting the wafer 400 to the end of the process and taking out the wafer 400 from the process chamber, the monitoring results of the multiple distance monitoring devices are continuously compared. Comparatively, when the wafer 400 is tilted in each process step, the problem can be detected in time, ensuring the safety of the wafer 400.

For example, in order to ensure the accuracy of the initial state of the wafer 400 when the wafer 400 is placed in the process chamber and further improve the safety of the wafer 400, as a preferred embodiment of the present invention, the controller 310 is also used to place the wafer 400 in the process chamber. After the transmission structure and the wafer lifting mechanism cooperate to transfer the wafer 400 to the carrier tray 100, the monitoring results of the multiple distance monitoring devices are obtained, whether the monitoring results of the multiple distance monitoring devices are consistent, and the monitoring results of the multiple distance monitoring devices are determined. When the monitoring results are inconsistent, it is determined that the state of the wafer 400 is abnormal.

As a preferred embodiment of the present invention, the controller 310 can not only determine whether the wafer is in a level state, but also determine other parameters of the wafer (such as thickness) based on the changes in the monitoring results of multiple distance monitoring devices before and after the wafer is transferred. , location, etc.) is normal, specifically:

The controller 310 is also used to obtain the monitoring results of multiple distance monitoring devices after the wafer transfer structure and the wafer lifting mechanism cooperate to transfer the wafer 400 to the carrier tray 100, and compare the initial distance measurement value with the multiple distance monitoring devices. When the monitoring results of multiple distance monitoring devices are consistent with the initial ranging value, it is determined that the film transmission is abnormal, where the initial ranging value is the distance H between the distance monitoring device itself and the bearing surface of the bearing tray 100 .

As shown in Figure 7, after the wafer transfer structure transfers the wafer to the process chamber, if the monitoring results (H1, H2) of the multiple distance monitoring devices are still equal to the distance between the distance monitoring device and the bearing surface of the bearing tray 100 H, it means that the wafer 400 does not land on the bearing surface of the bearing tray 100 normally, and it can be determined that the wafer transfer is abnormal.

In order to further ensure the accuracy of the initial state of the wafer 400 when placing the wafer 400 into the process chamber, as a preferred embodiment of the present invention, the controller 310 is also used to When the monitoring results of the distance monitoring device are inconsistent with the initial ranging value, compare the slide ranging value with the detection results of multiple distance monitoring devices. When the detection results of the multiple distance monitoring devices are consistent with the slide ranging value, determine The film transfer is normal. When the detection results of multiple distance monitoring devices are inconsistent with the distance measurement value of the carrier, it is determined that the thickness of the wafer 400 is abnormal. The distance measurement value of the carrier is the difference between the distance monitoring device itself and the bearing surface of the carrier tray 100. The difference obtained by subtracting the thickness X of the wafer 400 from the distance H between them.

In the embodiment of the present invention, the controller 310 can further control the distance monitoring device when the monitoring result of the distance monitoring device is inconsistent with the initial distance measurement value H, that is, after determining that the wafer 400 has smoothly landed on the bearing surface of the bearing tray 100 Verify whether the monitoring results H1 and H2 are the carrier distance measurement values (H-X), further ensuring the accuracy of the initial state of the wafer 400 when placing the wafer 400 in the process chamber.

It should be noted that both the initial distance measurement value H and the slide distance measurement value (H-X) can be directly monitored and determined by the distance monitoring device under normal conditions, for example, when a first distance measurement sensor is provided on the top of the process chamber. 210 and the second distance sensor 220, when the wafer 400 is not placed, the distance of the bearing surface can be measured by the first distance sensor 210 and the second distance sensor 220 to obtain the initial distance value H. , and after the wafer 400 is placed normally, the distance on the surface of the wafer 400 is measured through the first distance sensor 210 and the second distance sensor 220 to obtain the slide distance value (H-X).

Specifically, the reading of the first ranging sensor 210 can be defined as H1, and the reading of the second ranging sensor 220 can be defined as H2; when the wafer is not placed, the reading of the first ranging sensor 210 is H11. , the reading of the second ranging sensor 220 is H21; when the wafer is placed, the reading of the first ranging sensor 210 is H12, the reading of the second ranging sensor 220 is H22, and the reading of the first ranging sensor 210 is H22. The basic monitoring data corresponding to the detector 210 and the second ranging sensor 220 is as shown in Table 1-1 below. Before starting the semiconductor manufacturing process, first perform machine calibration and adjust the level of the carrier plate 100 (electrostatic chuck) degree, and adjust the position of the ranging sensor to ensure H11=H21=H.

As an optional implementation of the present invention, as shown in Figure 5, the semiconductor processing equipment also includes a mobile recorder 340. The mobile recorder 340 is used to record the theoretical height of the lifting mechanism of the wafer. When the wafer is normal During film transfer, the mobile recorder 340 is also used to record the theoretical height of the wafer lifting mechanism wafer 400 rising.

Specifically, as shown in FIG. 5 , the wafer lifting mechanism includes an ejection pin structure 300 , a motor controller 320 and a motor 330 . The ejector pin structure 300 includes a plurality (eg, three) ejector pins extending in the vertical direction and having the same height. A plurality of ejector pin holes extending to the bearing surface are formed on the bearing plate. The plurality of ejector pins are arranged on the plurality of ejector pins in one-to-one correspondence. In each of the ejector pin holes, the motor 330 is used to drive the ejector pin structure 300 to move in the vertical direction, so that the plurality of ejector pins extend upward into the multiple ejector pin holes or retract downward into the multiple ejector pin holes.

The controller 310 is a programmable logic controller (PLC) or an industrial computer. The controller 310 can control the feed amount of the motor 330 through the motor controller 320 (for example, it can be a servo driver), thereby controlling the motor 330 The height to drive the ejection pin structure 300 to rise and fall. The movement recorder 340 may be a motor encoder, and the controller 310 can also read the feed amount of the motor through the movement recorder 340 to obtain the height of the ejection pin structure 300 rising or driving the wafer 400 to rise.

As shown in Figure 6, when the ejector pin is raised from the lowest position (the position of the ejector pin structure 300 shown by the double-dotted line in the figure) to the exit of the ejector pin hole (that is, it is in contact with the bottom of the wafer 400), The reading G1 of the mobile recorder 340 is recorded as the basic reading, and the theoretical height that the ejector pin structure 300 drives the wafer 400 to rise is the reading G of the mobile recorder 340 minus the basic reading G1, that is, (G-G1).

It should be noted that even if the initial state of the wafer 400 is normal, there is still a risk of tilting due to the electrostatic force when the wafer 400 is lifted up (as shown in FIG. 6 ). For example, as shown in FIG. 8 , when the wafer lifting mechanism lifts the wafer 400 to rise, one side of the wafer 400 is attracted to the bearing surface of the carrier tray 100 due to electrostatic force, thereby causing an angle of the wafer 400 Abnormally, the wafer transfer structure will collide with the wafer 400 after entering the process chamber when picking up the wafer; or, as shown in Figure 9, the surrounding sides of the wafer 400 are adsorbed on the bearing surface of the bearing tray 100, and the wafer holder When the lifting mechanism lifts the wafer 400, it lifts up the central part of the wafer 400, which causes excessive pressure on the wafer 400 and causes it to break.

Among them, the problem of abnormal angle of the wafer 400 during the lifting process can be monitored by comparing the monitoring results of multiple distance monitoring devices. However, the situation that only the center of the wafer 400 is lifted cannot be effectively monitored by the above method.

In order to solve the above technical problems and prevent the wafer 400 from being fragmented when it is lifted up, as a preferred embodiment of the present invention, the controller 310 is also used to lift the wafer 400 during the process of the wafer lifting mechanism. Instantly obtain the theoretical height (G-G1) of the wafer lifting mechanism lifting the wafer 400 recorded by the mobile recorder, and monitor the bearing surface of the device and the bearing tray based on the theoretical height (G-G1) and the pre-obtained distance. and the thickness of the wafer 400, the theoretical distance measurement value is calculated and obtained. The theoretical distance measurement value is the distance H between the distance monitoring device and the bearing surface of the carrier tray 100 minus the thickness X of the wafer 400 and then minus The theoretical height (G-G1) at which the wafer lifting mechanism lifts the wafer 400 recorded by the mobile recorder is the difference obtained after H-X-(G-G1), which is H-X-(G-G1).

The controller 310 is also used to compare the above theoretical distance measurement value with multiple distance monitoring devices. When the monitoring results of multiple distance monitoring devices are consistent with the theoretical distance measurement value, the status of the wafer 400 is determined to be normal (i.e., the situation shown in Figure 6); when there is at least one distance monitoring device whose monitoring result is greater than the theoretical distance measurement value. When measuring the distance value, it is determined that the state of the wafer 400 is abnormal.

As an optional implementation mode of the present invention, the controller 310 is also used when the monitoring results of all distance monitoring devices are greater than the theoretical distance measurement value H-X-(G-G1) (that is, when the height of the wafer 400 is lower than its theoretical height) ), it is determined that the overall bonding abnormality of the wafer 400 occurs (ie, the situation shown in FIG. 9 ).

As another optional implementation of the present invention, the controller 310 is also used to detect when the monitoring results of some distance monitoring devices among the plurality of distance monitoring devices are greater than the theoretical distance measurement value H-X-(G-G1) (i.e., the wafer 400 When the height of a part of the position is lower than its theoretical height), it is determined that a local sticking abnormality occurs in the wafer 400 .

In order to further improve the safety of the wafer 400, as a preferred embodiment of the present invention, the controller 310 is also used to control the wafer 400 after determining that the state of the wafer 400 is abnormal (for example, an overall bonding abnormality or a local bonding abnormality occurs). The circular lifting mechanism descends to put the wafer 400 back on the bearing surface of the bearing tray 100, thereby restoring the strain on the surface of the wafer 400 in time and preventing the wafer 400 from being broken.

In order to further improve the safety of the wafer 400, as a preferred embodiment of the present invention, the controller 310 is also used to detect that the monitoring results of some distance monitoring devices among the plurality of distance monitoring devices are less than the theoretical distance measurement value H-X-(G- G1) (that is, when the height of the wafer 400 is higher than its theoretical height), it is determined that a jump abnormality occurs in the wafer 400 .

In order to facilitate operators to promptly detect abnormal wafer status problems and take corresponding measures in a timely manner, and further improve the safety of semiconductor processing equipment, as a preferred embodiment of the present invention, the controller 310 is also used to determine whether the wafer 400 status is abnormal (angle Abnormal, abnormal Normal, abnormal thickness, abnormal sheet sticking, abnormal sheet jumping, etc.), an alarm signal will be output. The embodiment of the present invention does not specifically limit the form of the alarm signal. For example, optionally, the alarm signal may include a flashing alarm of a semiconductor process equipment indicator light, a buzzer alarm, a pop-up alarm window on a display screen, etc.

As a second aspect of the present invention, a wafer status monitoring method is provided, which is applied to the semiconductor processing equipment (implemented by the controller 310) provided by the embodiment of the present invention. As shown in Figure 10, the method includes: step S1, During the lifting action of the wafer lifting mechanism, the monitoring results of multiple distance monitoring devices are obtained instantly; step S2 is to determine whether the monitoring results of the multiple distance monitoring devices are consistent; if the monitoring results of the multiple distance monitoring devices are inconsistent, Then it is determined that the state of wafer 400 is abnormal.

In the wafer status monitoring method provided by the present invention, the controller 310 can instantly obtain the distance monitoring results (i.e., distance monitoring results) of multiple distance monitoring devices on the top of the process chamber during the lifting action of the wafer lifting mechanism. Monitor the distance between the device itself and different positions on the carrier tray), so that abnormal wafer status problems (such as abnormal angle, abnormal thickness, abnormal wafer sticking, abnormal wafer jump, abnormal wafer transfer) can be detected in time to avoid subsequent actions that may cause damage to the wafer. Further damage is caused to the wafer 400, thereby improving the safety of the wafer 400, thereby reducing the maintenance cost of the process chamber, and ensuring the product yield of the semiconductor process.

In order to ensure the accuracy of the initial state of the wafer 400 when the wafer 400 is placed in the process chamber and further improve the safety of the wafer 400, as a preferred embodiment of the present invention, the method also includes: step S01. After the transmission structure and the wafer lifting mechanism cooperate to transfer the wafer 400 to the carrier tray 100, the monitoring results of multiple distance monitoring devices are obtained, and multiple distance monitoring devices are judged. Whether the monitoring results of the distance monitoring devices are consistent, and when the monitoring results of the multiple distance monitoring devices are inconsistent, it is determined that the state of the wafer 400 is abnormal (the wafer 400 is tilted).

As a preferred embodiment of the present invention, the controller 310 can not only determine whether the wafer is in a level state, but also determine other parameters of the wafer (such as thickness) based on the changes in the monitoring results of multiple distance monitoring devices before and after the wafer is transferred. , position, etc.) is normal. Specifically, the method also includes: Step S02: After the wafer transfer structure and the wafer lifting mechanism cooperate to transfer the wafer 400 to the carrier tray 100, obtain the monitoring results of multiple distance monitoring devices. , compare the initial ranging value with the monitoring results of multiple distance monitoring devices. When the monitoring results of multiple distance monitoring devices are consistent with the initial ranging value, it is determined that the wafer transfer is abnormal (there is no wafer on the electrostatic chuck after the wafer transfer ). The initial distance measurement value is the distance H between the distance monitoring device and the bearing surface of the bearing tray 100 .

In order to further ensure the accuracy of the initial state of the wafer 400 when the wafer 400 is placed in the process chamber, as a preferred embodiment of the present invention, the method also includes: step S03, monitoring results of multiple distance monitoring devices and the initial state of the wafer 400. When the ranging values are inconsistent, compare the slide ranging values with the detection results of multiple distance monitoring devices. When the detection results of the multiple distance monitoring devices are consistent with the slide ranging values, it is determined that the slide transfer is normal. When the detection results of the monitoring device are inconsistent with the carrier distance measurement value, it is determined that the thickness of the wafer 400 is abnormal, where the carrier distance measurement value is the distance H between the distance monitoring device and the bearing surface of the carrier tray 100 minus the wafer 400 The thickness of X.

In order to avoid fragmentation when the wafer 400 is lifted up, as a preferred embodiment of the present invention, the semiconductor processing equipment also includes a mobile recorder, and the mobile recorder is used to record the lifting of the wafer 400 by the wafer lifting mechanism. Theoretical height, the method also includes: step S3, during the process of lifting the wafer 400 by the wafer lifting mechanism, immediately Obtain the theoretical height (G-G1) at which the wafer lifting mechanism lifts the wafer 400 recorded by the mobile recorder, and monitor the distance between the device and the bearing surface of the carrier plate based on the theoretical height (G-G1) and the pre-obtained distance. and the thickness of the wafer 400, and calculate to obtain a theoretical distance measurement value. The theoretical distance measurement value is the distance H between the distance monitoring device and the bearing surface of the carrier tray 100 minus the thickness X of the wafer 400 and then minus the movement. The theoretical height (G-G1) at which the wafer lifting mechanism lifts the wafer 400 recorded by the recorder is the difference obtained after H-X-(G-G1), which is H-X-(G-G1). Compare the theoretical ranging value with the monitoring results of multiple distance monitoring devices. When the monitoring results of the multiple distance monitoring devices are consistent with the theoretical ranging value, it is determined that the status of wafer 400 is normal (i.e., the situation shown in Figure 6); when there is When the monitoring result of at least one distance monitoring device is greater than the theoretical distance measurement value, it is determined that the state of the wafer 400 is abnormal. For example, when the monitoring results of all distance monitoring devices are greater than the theoretical distance measurement value H-X-(G-G1) (that is, when the height of the wafer 400 is lower than its theoretical height), it is determined that the overall sticking abnormality of the wafer 400 has occurred (that is, The situation shown in Figure 9).

As an optional implementation mode of the present invention, the method also includes: step S4, when the monitoring results of some of the distance monitoring devices among the plurality of distance monitoring devices are greater than the theoretical distance measurement value H-X-(G-G1) (i.e., the wafer 400 is lower than its theoretical height), it is determined that a local sticking abnormality occurs in the wafer 400 .

In order to further improve the safety of the wafer 400, as a preferred embodiment of the present invention, the method also includes: step S41, after determining that the state of the wafer 400 is abnormal (for example, an overall sticking abnormality or a local sticking abnormality occurs), The wafer lifting mechanism is controlled to descend to place the wafer 400 back on the bearing surface of the bearing tray 100, thereby restoring the strain on the surface of the wafer 400 in a timely manner and preventing the wafer 400 from being broken.

In order to further improve the safety of the wafer 400, as a preferred method of the present invention In one embodiment, the method further includes: step S5: when the monitoring results of some of the distance monitoring devices among the plurality of distance monitoring devices are less than the theoretical distance measurement value H-X-(G-G1) (that is, the height of the wafer 400 is higher than its theoretical height) ), it is determined that a skip abnormality occurs in the wafer 400 .

In order to facilitate operators to timely detect abnormal wafer status problems and take corresponding measures in a timely manner, and further improve the safety of semiconductor processing equipment, as a preferred embodiment of the present invention, the method also includes: step S6, determining whether the wafer 400 status is abnormal (Abnormal angle, abnormal film transfer, abnormal thickness, abnormal film sticking, abnormal film jumping, etc.), an alarm signal is output. The embodiment of the present invention does not specifically limit the form of the alarm signal. For example, optionally, the alarm signal may include a flashing alarm of a semiconductor process equipment indicator light, a buzzer alarm, a pop-up alarm window on a display screen, etc.

In order to facilitate the understanding of technicians, the following provides a situation where two distance monitoring devices, namely the first distance sensor 210 and the second distance sensor 220 are provided on the top of the process chamber. The controller 310 executes the present invention. Specific examples of the wafer status monitoring method provided by the embodiment:

As shown in FIG. 11 , after the wafer transfer structure and the wafer lifting mechanism cooperate to transfer the wafer 400 to the carrier tray 100 , the controller 310 obtains the monitoring result H1 and the second distance measurement result of the first ranging sensor 210 The sensor 220 monitors the result H2 and determines whether the two monitoring results H1 and H2 are consistent. When H1 and H2 are not equal, it is determined that the state of the wafer 400 is abnormal (the wafer 400 is tilted).

When H1 and H2 are equal, further determine whether the two monitoring results H1 and H2 are consistent with the initial ranging value H. If H1 and H2 are consistent with the initial ranging value H, it is determined that the film transmission is abnormal. Normal (there is no wafer on the electrostatic chuck after transferring). If H1 and H2 are not the same as the initial ranging value H, then compare the slide ranging value H-X with the monitoring results H1 and H2 of the two distance monitoring devices. Both monitoring results H1 and H2 are consistent with the slide ranging value H-X. When, it is determined that the film transfer is normal; when the two monitoring results H1 and H2 are inconsistent with the film distance measurement value H-X, it is determined that the thickness of the wafer 400 is abnormal.

After the semiconductor process is completed, the electrostatic adsorption force (dechuck) of the electrostatic chuck on the wafer is unloaded. During the process of lifting the wafer 400 by the wafer lifting mechanism, as shown in Figure 12, the controller 310 judges the two monitoring results again. Whether H1 and H2 are consistent. If H1 and H2 are not equal, it is determined that the state of the wafer 400 is abnormal (the wafer 400 is tilted); if H1 and H2 are equal, the wafer is not tilted and the wafer 400 can continue to be lifted.

During the rising process of the wafer 400, the controller 310 reads the feed amount of the motor through the mobile recorder 340, and obtains the theoretical height G-G1 of the ejection pin structure 300 driving the wafer 400 to rise, and then obtains the first distance sensor. 210 and the theoretical ranging value H-X-(G-G1) of the second ranging sensor 220.

As shown in FIG. 12 , when the monitoring results H1 and H2 of the first ranging sensor 210 and the second ranging sensor 220 are both consistent with the theoretical ranging value H-X-(G-G1), the controller 310 determines The status of wafer 400 is normal (i.e., the situation shown in Figure 6); when there is at least one distance monitoring device whose monitoring result is greater than the theoretical distance measurement value (i.e., when H1 and/or H2 is greater than H-X-(G-G1)), it is determined Wafer 400 has a sticking abnormality (i.e., the situation shown in Figure 9); when the monitoring results of some of the two distance monitoring devices are smaller than the theoretical distance measurement value H-X-(G-G1) (i.e., H1 or H2 is smaller than H-X -(G-G1)), it is determined that a jump abnormality occurs in wafer 400.

In the wafer status monitoring method provided by the present invention, during the lifting action of the wafer lifting mechanism, the distances of multiple distance monitoring devices on the top of the process chamber are obtained in real time. The monitoring results (i.e., the distance between the distance monitoring device itself and different positions on the carrier tray) can be used to detect abnormal wafer status problems (such as abnormal angle, abnormal thickness, abnormal wafer sticking, abnormal wafer jump, and abnormal wafer transfer) in a timely manner. ), avoid further damage to the wafer caused by subsequent actions, improve the safety of the wafer, reduce the maintenance cost of the process chamber, and ensure the product yield of the semiconductor process.

The foregoing content summarizes the features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments described herein. Those skilled in the art should also understand that such equivalent constructions do not depart from the spirit and scope of the disclosure, and that they can be variously changed, replaced, and altered herein without departing from the spirit and scope of the disclosure.

210: First ranging sensor

220: Second ranging sensor

300:Thimble structure

310:Controller

320:Motor controller

330:Motor

340:Mobile recorder

400:wafer

100: Carrying tray

Claims (10)

A semiconductor processing equipment, including a process chamber and a carrier tray disposed in the process chamber. The carrier tray is used to carry wafers. The carrier tray is provided with a wafer lifting mechanism for lifting wafers. , wherein a plurality of distance monitoring devices are provided on the top of the process chamber, and the plurality of distance monitoring devices are used to respectively monitor the distances between themselves and multiple different positions on the carrier tray; the semiconductor processing equipment also includes: A controller, used to instantly obtain the monitoring results of multiple distance monitoring devices during the lifting action of the wafer lifting mechanism, determine whether the monitoring results of the multiple distance monitoring devices are consistent, and determine whether the monitoring results of the multiple distance monitoring devices are consistent. When the monitoring results of the distance monitoring device are inconsistent, it is determined that the state of the wafer is abnormal; there are two distance monitoring devices, and the two distance monitoring devices are symmetrical about the axis position of the carrier plate, and the distance monitoring device is on the wafer. The projection positions on the circular surface are close to the edge of the corresponding side of the wafer. The semiconductor processing equipment according to claim 1, further comprising a mobile recorder for recording the theoretical lifting height of the wafer lifting mechanism: the controller is also used for recording the lifting height of the wafer lifting mechanism. During the lifting action of the lifting mechanism, the theoretical height of the wafer lifting mechanism recorded by the mobile recorder is instantly obtained, and based on the theoretical height and the distance obtained in advance, the load capacity of the monitoring device and the carrier plate is The distance between the surfaces and the thickness of the wafer are calculated to obtain a theoretical distance measurement value. The theoretical distance measurement value is the distance between the distance monitoring device and the bearing surface of the bearing tray minus the thickness of the wafer and then minus The difference obtained after the theoretical height; The controller is also used to compare the theoretical distance measurement value with the monitoring results of multiple distance monitoring devices. When the monitoring results of multiple distance monitoring devices are consistent with the theoretical distance measurement value, it is determined that the wafer is in a normal state; When the monitoring result of at least one of the distance monitoring devices is greater than the theoretical distance measurement value, it is determined that the wafer has a sticking abnormality. The semiconductor processing equipment as described in claim 2, wherein the controller is also used to determine that a local occurrence of the wafer occurs when the monitoring results of some of the distance monitoring devices among the plurality of distance monitoring devices are greater than the theoretical distance measurement value. Abnormal stickiness. The semiconductor processing equipment as described in claim 2, wherein the controller is also used to determine that the wafer has jumped when the monitoring results of some of the distance monitoring devices among the plurality of distance monitoring devices are less than the theoretical distance measurement value. Film is abnormal. The semiconductor processing equipment according to claim 2, wherein the controller is also used to control the wafer lifting mechanism to descend to put the wafer back to the carrier tray after determining that the wafer has abnormal adhesion. on the bearing surface. The semiconductor processing equipment of claim 1, further comprising a wafer transfer structure, the wafer transfer structure being used to cooperate with the wafer lifting mechanism to transfer the wafer to the carrier and to place the wafer on the carrier. The wafer is transferred out of the process chamber; the controller is also used to obtain monitoring results of multiple distance monitoring devices after the wafer transfer structure cooperates with the wafer lifting mechanism to transfer the wafer to the carrier tray. , determine whether the monitoring results of multiple distance monitoring devices are consistent, and determine whether the monitoring results of multiple distance monitoring devices are inconsistent. If so, it is determined that the state of the wafer is abnormal. The semiconductor processing equipment of claim 6, wherein the controller is also used to obtain a plurality of the distance monitoring devices after the wafer transfer structure cooperates with the wafer lifting mechanism to transfer the wafer to the carrier tray. The monitoring results are compared with the initial ranging value and the monitoring results of multiple distance monitoring devices. When the monitoring results of multiple distance monitoring devices are consistent with the initial ranging value, it is determined that the film transmission is abnormal, wherein the initial measuring The distance value is the distance between the distance monitoring device itself and the bearing surface of the bearing plate. The semiconductor processing equipment of claim 7, wherein the controller is also used to compare the distance measurement value of the slide with the plurality of distance monitoring devices when the monitoring results of the multiple distance monitoring devices are inconsistent with the initial distance measurement value. The detection results of the device are determined to be normal when the detection results of multiple distance monitoring devices are consistent with the distance measurement value of the slide; when the detection results of multiple distance monitoring devices are inconsistent with the distance measurement value of the slide When , it is determined that the thickness of the wafer is abnormal, wherein the distance measurement value of the slide is the difference obtained by subtracting the thickness of the wafer from the distance between the distance monitoring device itself and the bearing surface of the bearing tray. The semiconductor processing equipment according to any one of claims 1 to 8, wherein the distance monitoring device is a distance measuring sensor. A wafer status monitoring method, applied to the semiconductor process equipment described in any one of claims 1 to 9, including: during the lifting action of the wafer lifting mechanism, instantly acquiring a plurality of the distance monitoring and determine whether the monitoring results of multiple distance monitoring devices are consistent; if the monitoring results of multiple distance monitoring devices are inconsistent, it is determined that the state of the wafer is abnormal.

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