TWI856726B - Pad raising mechanism in wafer positioning pedestal for semiconductor processing - Google Patents

Abstract

An assembly used in a process chamber for depositing a film on a wafer. A pedestal assembly includes a pedestal movably mounted to a main frame. A lift pad rests upon the pedestal and moves with the pedestal assembly. A raising mechanism separates the lift pad from the pedestal, and includes a hard stop fixed to the main frame, a roller attached to the pedestal assembly, a slide moveably attached to the pedestal assembly, a lift pad bracket interconnected to the slide and a pad shaft extending from the lift pad, and a lever rotatably attached to the lift pad bracket. The lever rests on the roller when not engaged with the upper hard stop. When the pedestal assembly moves upwards, the lever rotates about a pin when engaging the upper hard stop and roller, and separates the lift pad from the pedestal by a process rotation displacement.

Description

Pad lifting mechanism in wafer positioning base for semiconductor processing

Embodiments of the present invention relate to methods and apparatus for processing semiconductor substrates, and more particularly, to a wafer alignment pedestal for processing wafers with different wafer-to-pedestal orientations.

Improved film uniformity is important in plasma enhanced chemical vapor deposition (PECVD) and plasma enhanced atomic layer deposition (ALD) technologies. The chamber systems that perform PECVD and ALD are associated with hardware features that lead to non-uniform film deposition. For example, hardware features can be associated with chamber asymmetry and asymmetry with the pedestal. In addition, many processes experience azimuthal non-uniformity that has many causes. As customers push to place the die closer to the wafer edge, the numerical contribution of this azimuthal non-uniformity to the overall non-uniformity increases. Despite best efforts to minimize damage and/or non-uniform deposition profiles, conventional PECVD and plasma ALD approaches are in need of improvement.

In particular, multi-station modules performing PECVD and ALD are characterized by large open reactors that can cause azimuthal non-uniformities, such as non-uniformity in the theta direction (NU). For example, some non-uniformities can cause characteristic film thicknesses to tilt in the axis delivery mechanism toward the center of the reactor. Non-uniformities also exist in single-station modules due to non-uniform physical chamber geometry, including those caused by assembly and component manufacturing tolerances.

Traditionally, deposition non-uniformity has been compensated by physically tilting the showerhead so that it is intentionally oriented non-parallel to the pedestal. While not a perfect solution, it has historically been effective. However, the effectiveness of this solution has become increasingly limited, especially as die size decreases and the edge of the wafer becomes the source of die buildup.

Processing wafers in multiple orientations without rotating hardware features has been shown to be effective for filtering azimuthal non-uniformity. The most basic prior art approach currently involves partially processing a wafer, removing the wafer from a processing chamber, rotating the wafer in a separate wafer handler, and then reinserting the wafer for further processing at a new orientation. The primary advantage of this approach is that the hardware inside the chamber is not rotated. However, this prior art solution has the disadvantages of throughput, contamination, and significant additional hardware.

Another solution in the prior art is to rotate the entire pedestal during processing. However, this solution has the disadvantageous characteristic of rotating with the wafer with respect to non-uniformities of the pedestal. In this case, the pedestal may have non-uniform characteristics that may not be offset during processing and may appear on the wafer. Moreover, when the entire pedestal is rotated during processing, the edge effect of the wafer in the pocket is another type of non-uniformity that rotates directly with the wafer. That is, the non-uniformity is not significantly improved in the case of pedestal rotation (such as pedestal rotation in ALD oxide deposition). Furthermore, in addition to limited performance, rotating the entire pedestal requires the cost of delivering RF power through the rotating pedestal. This requires expensive circuitry for impedance matching via slip rings to deliver sufficient RF power to the plasma. Rotating the entire base also complicates the delivery of fluids and gases, such as for cooling. In addition, the heating system present in the base also needs to be rotated, adding cost and complexity.

The disclosure is presented in this article.

Embodiments of the present invention provide improved film uniformity during PECVD and ALD processes in single-station and multi-station systems. Embodiments of the present disclosure provide for wafer rotation without rotating the pedestal, which advantageously filters out both chamber and pedestal asymmetries.

Embodiments of the present disclosure include an assembly for depositing a film on a wafer in a processing chamber. The assembly includes a base assembly having a base movably mounted to a main frame. The assembly includes a lift pad configured to be placed on a base top surface of the base and to move with the base assembly. The assembly includes a lift pad raising mechanism configured to separate the lift pad from the base, the lift pad raising mechanism including an upper hard stop, a first roller, a slide, a lift pad bracket, and a lever. The upper hard stop is fixed relative to the main frame. The first roller is attached to the base assembly. The slide is movably attached to the base assembly. The lift pad bracket is interconnected to the slider and to the pad shaft, wherein the pad shaft extends from the lift pad along a central axis. The lever is rotatably attached to the lift pad bracket by a pin, wherein the lever is disposed on the first roller in a neutral position when the lever is not engaged with the upper hard stop. With respect to the lift pad raising mechanism, when the base assembly moves upward, the lever is configured to rotate about the pin when engaged with the upper hard stop and the first roller and separate the lift pad from the base top surface by a process rotational displacement.

Other embodiments of the present disclosure include an assembly for depositing a film on a wafer in a processing chamber. The assembly includes a base assembly having a base movably mounted to a main frame. The assembly includes a lift pad configured to be placed on a base top surface of the base and to move with the base assembly. The assembly includes a lift pad raising mechanism configured to separate the lift pad from the base, the lift pad raising mechanism including an upper hard stop, a lower hard stop, a first roller, a second roller, a slide, a lift pad bracket, and a lever. The upper hard stop is fixed relative to the main frame. The lower hard stop is fixed relative to the main frame and is arranged below the upper hard stop relative to the main frame. The first roller is attached to the base assembly. The second roller is attached to the base assembly. The slide is movably attached to the base assembly. The lift pad bracket is interconnected to the slide and to the pad shaft, wherein the pad shaft extends from the lift pad along a center axis. The lever is rotatably attached to the lift pad bracket by a pin, wherein the lever is disposed on the first roller in a neutral position when the lever is not engaged with the upper hard stop. With respect to the lift pad raising mechanism, when the base assembly moves upward, the lever is configured to rotate about the pin when engaged with the upper hard stop and the first roller and separate the lift pad from the base top surface by a process rotational displacement. With respect to the lift pad raising mechanism, when the base assembly moves downward, the lever is configured to rotate about the pin when engaging with the lower hard stop and the second roller, and to cause the lift pad to be separated from the base top surface by an end effector path displacement.

Still other embodiments of the present disclosure include an assembly for depositing a film on a wafer in a processing chamber. The assembly includes a base assembly, the base assembly including a base movably mounted to a main frame. The assembly includes a lift pad, the lift pad being configured to be placed on a base top surface of the base and to move with the base assembly. The assembly includes a lift pin assembly, the lift pin assembly including a plurality of lift pins extending through a plurality of base shafts disposed within the base. The assembly includes a lift pad elevating mechanism configured to separate the lift pad from the base, wherein the lift pad elevating mechanism includes an upper hard stop, a first roller, a slide, a lift pad bracket, and a lever. The upper hard stop is fixed relative to the main frame. The first roller is configured to be attached to the base assembly. The slider is configured to be movably attached to the base assembly. The lift pad bracket is configured to be interconnected to the slider and to a pad shaft, wherein the pad shaft extends from the lift pad along a central axis. The lever is configured to be rotatably attached to the lift pad bracket by a pin, wherein the lever is disposed on the first roller in a neutral position when the lever is not engaged with the upper hard stop. With respect to the lift pad raising mechanism, when the base assembly moves upward, the lever is configured to rotate about the pin when engaged with the upper hard stop and the first roller and separate the lift pad from the base top surface by a process rotational displacement.

In another embodiment, an assembly for depositing a film on a wafer in a processing chamber is described. The assembly includes: a base assembly mounting device for movably mounting a base assembly including a base to a main frame; a lifting pad moving device for moving a lifting pad together with the base assembly, the lifting pad being configured to be placed on a base top surface of the base; and a lifting pad separating device for separating the lifting pad from the base. The lifting pad separation device for separating the lifting pad from the base includes: an upper hard stop fixing device for fixing the upper hard stop relative to the main frame; a first roller attachment device for attaching the first roller to the base assembly; a slide attachment device for movably attaching the slide to the base assembly; a lifting pad bracket interconnection device for interconnecting the lifting pad bracket to the slide and the pad shaft, wherein the pad shaft is along the center an axis extending from the lifting pad; and a lever attachment device for rotatably attaching the lever to the lifting pad bracket by a pin, wherein when the lever is not engaged with the upper hard stop, the lever is placed on the first roller in a neutral position; wherein when the base assembly moves upward, the lever is configured to rotate about the pin when engaged with the upper hard stop and the first roller and separate the lifting pad from the top surface of the base by a process rotational displacement.

The assembly includes further embodiments. In one embodiment, the assembly further includes means for attaching a base bracket to the base, and means for movably attaching the base bracket to the main frame, wherein the base bracket is configured to move the base relative to the main frame along a central axis; and central axis extension means for extending a central axis from the base along the central axis, the central axis being configured to move with the base; wherein the pad shaft is configured to separate the lifting pad from the base and is disposed within the central axis. In addition, in one embodiment, when the lever pin rotates, the lifting pad bracket and the slider move upwardly relative to the base assembly, so that the lifting pad is configured to move upwardly along the central axis relative to the top surface of the base. Furthermore, in one embodiment, when the lever is rotated around the pin, the lift pad and the base assembly move in a 2 to 1 ratio. Furthermore, in one embodiment, when the lever is in a neutral position and not engaged with the upper hard stop, there is no relative movement between the lever and the base assembly. Furthermore, in one embodiment, the lift pad movement device further includes: a pad top surface extension device for extending the pad top surface from the central axis; and a pad bottom surface placement device for placing the pad bottom surface on the base top surface, the pad top surface being configured to support the wafer when the wafer is placed thereon. Furthermore, in one embodiment, the diameter of the pad top surface is smaller than the wafer diameter. Moreover, in one embodiment, the diameter of the pad top surface is approximately the same size as the wafer diameter. Furthermore, in one embodiment, the pad motion device rotates the pad between at least a first angular orientation and a second angular orientation relative to the base top surface when the pad is separated from the base. Furthermore, in one embodiment, the pad bracket interconnection device for interconnecting the pad bracket to the slider and the pad shaft includes a device for interconnecting the pad bracket to a ferromagnetic seal interconnected to the pad shaft, wherein the ferromagnetic seal is configured to provide a vacuum seal around the pad shaft when the pad shaft is rotating or not rotating.

In yet other embodiments, another assembly for depositing a film on a wafer in a processing chamber is described. The assembly includes: a base assembly mounting device for movably mounting a base assembly including a base to a main frame; a lifting pad placing device for placing the lifting pad on the base top surface of the base and moving the lifting pad together with the base assembly; and a lifting pad separating device for separating the lifting pad from the base. The lifting pad separation device for separating the lifting pad from the base includes: a lever assembly moving device for moving the lever assembly relative to the base assembly when the lever assembly is actuated; a ferromagnetic seal assembly surrounding device for surrounding the ferromagnetic seal assembly around the pad shaft, and a vacuum seal providing device for allowing the ferromagnetic seal assembly to move relative to the base assembly when the lever assembly is actuated. A vacuum seal is provided around the ferromagnetic seal assembly, which is interconnected to the lever assembly; and a yoke assembly interconnection device for interconnecting the yoke assembly to the lever assembly, and an equal force applying device for causing the yoke assembly to apply equal forces to opposite sides of the ferromagnetic seal assembly to offset the torque applied to the ferromagnetic seal assembly when the lever assembly is actuated.

The assembly includes further embodiments. In one embodiment, the lever assembly motion device includes: an upper hard stop fixing device for fixing the upper hard stop relative to the main frame; a first roller attachment device for attaching the first roller to the base assembly; a slider attachment device for movably attaching the slider to the base assembly; a lifting pad bracket interconnection device for interconnecting the lifting pad bracket to the slider and the pad shaft, wherein the pad shaft is self-rotating along the center axis. The lifting pad is extended; and a lever attachment device for rotatably attaching the lever to the lifting pad bracket by a pin, wherein the lever is placed on the first roller in a neutral position when the lever is not engaged with the upper hard stop; wherein when the base assembly moves upward, the lever rotation device rotates the lever around the pin when the lever engages with the upper hard stop and the first roller, and separates the lifting pad from the top surface of the base by a process rotation displacement. In one embodiment, the assembly further includes a ferromagnetic seal assembly attachment device for attaching the ferromagnetic seal assembly to the pad shaft at a first end thereof, wherein the ferromagnetic seal assembly includes a first connector arm and a second connector arm located at a second end opposite to the first end of the ferromagnetic seal assembly, the first connector arm and the second connector arm are located on opposite sides of the ferromagnetic seal assembly and are equidistant from the pad shaft; and a yoke assembly contact device for causing the yoke assembly to contact the ferromagnetic seal assembly at the first connector arm and the second connector arm; and a device for causing the yoke assembly to apply equal forces to the first connector arm and the second connector arm, wherein the first connector arm and the second connector arm are arranged 180 degrees apart about a center axis. In one embodiment, the yoke assembly contacting device for contacting the yoke assembly with the ferromagnetic seal assembly includes: a yoke base attachment device for rotatably attaching the yoke base to the lifting pad bracket by a second pin, wherein the yoke base is rotatable about a pin axis; a yoke arm attachment device for attaching the yoke arm to the yoke base with a parallel pin axis extending from the yoke base, the yoke arm The yoke is deflected from the pin by a radial displacement, wherein the yoke is rotatable about the pin axis; and a fork end setting device is used to set the fork end on the yoke away from the yoke base, the fork end includes a first fork extension and a second fork extension, the first fork extension is configured to contact the first connector arm, and the second fork extension is configured to contact the second connector arm. In one embodiment, the lifting pad partition device for separating the lifting pad from the base further includes: a rotary motor attachment device for attaching the rotary motor to the pad shaft via a belt, the rotary motor and the belt being configured to rotate the pad shaft around a central axis; and a disc attachment device for attaching a belt-driven disc of a ferromagnetic seal assembly to the belt and to the pad shaft. In one embodiment, the base assembly mounting device for movably mounting the base assembly further includes: a device for attaching a base bracket to the base, and a device for movably attaching the base bracket to the main frame, wherein the base bracket is configured to move the base relative to the main frame along a center axis; a center axis extending device for extending the center axis from the base along the center axis, and the center axis is configured to move with the base; and a lifting pad separating device for separating the lifting pad from the base using a pad shaft, and wherein the pad shaft is configured within the center axis. In one embodiment, the means for movably sliding the lift pad bracket upward relative to the base assembly when the lever is rotated about the pin such that the lift pad is configured to move upward along a central axis relative to the base top surface. In another embodiment, when the lever is in a neutral position and not engaged with the upper hard stop, there is no relative movement between the lever and the base assembly. In another embodiment, the diameter of the pad top surface is less than the diameter of the wafer. In another embodiment, the lifting pad partitioning device for separating the lifting pad from the base includes a lifting pad rotating device for rotating the lifting pad between at least a first angular orientation and a second angular orientation relative to the top surface of the base when the lifting pad rotating device is separated from the base.

These and other advantages will be understood by one of ordinary skill in the art upon reading the entire specification and claims.

Although the following detailed description contains many specific details for the purpose of illustration, anyone with ordinary skill in the art will understand that many variations and modifications to the following details are within the scope of the present disclosure. Therefore, the embodiments of the present disclosure described below are intended to illustrate the scope of the patent application that follows this description without any loss of generality and without any limitation.

In general, various embodiments of the present disclosure describe systems and methods that provide improved film uniformity during wafer processing (e.g., PECVD and ALD processing) in single-station and multi-station systems. In particular, embodiments of the present disclosure provide for rotating the wafer without rotating the pedestal to filter out both chamber and pedestal asymmetries. In this manner, azimuthal non-uniformities due to chamber and pedestal asymmetries are minimized to achieve full wafer-wide film uniformity during processing (e.g., PECVD, ALD, etc.).

With the above general understanding of the various embodiments, example details of the embodiments will now be described with reference to the various figures. Like numbered parts and/or components in one or more of the figures are intended to generally have the same configuration and/or function. In addition, the figures may not be drawn to scale, but are intended to illustrate and emphasize novel concepts. Obviously, the embodiments of the present invention can be implemented without some or all of these specific details. On the other hand, well-known process operations are not described in detail to avoid unnecessary confusion of the embodiments of the present invention.

FIG. 1 illustrates a reactor system 100 that may be used to deposit films on a substrate, such as those formed in an atomic layer deposition (ALD) process. These reactors may use more than two heaters, and a common terminal configuration may be used in this example reactor to control temperature for uniformity or custom settings. More specifically, FIG. 1 depicts a substrate processing system 100 that is used to process a wafer 101. The system includes a chamber 102 having a lower chamber portion 102b and an upper chamber portion 102a. A center column is configured to support a base 140, which in one embodiment is a powered electrode. The base 140 is electrically coupled to a power source 104 via a matching network 106. The power source is controlled by a control module 110 (e.g., a controller). The control module 110 is configured to operate the substrate processing system 100 by executing the process input and control 108. The process input and control 108 may include a process recipe, such as power levels, timing parameters, process gases, mechanical movement of the wafer 101, etc., such as to deposit or form a film on the wafer 101.

The center column also includes lift pins (not shown), each of which is actuated by a corresponding lift pin actuation ring 120 as controlled by a lift pin control 122. The lift pins are used to lift the wafer 101 from the base 140 to allow the end effector to pick up the wafer, and to lower the wafer 101 after the end effector has placed the wafer. The substrate processing system 100 further includes a gas supply manifold 112, which is connected to a process gas 114, such as a gas chemical supplied from the facility. The control module 110 controls the delivery of the process gas 114 through the gas supply manifold 112 depending on the process being performed. The selected gas then flows into the showerhead 150 and is distributed in the spatial volume defined between the surface of the showerhead 150 facing the wafer 101 and the wafer 101 disposed on the pedestal 140. In the ALD process, the gas may be a reactant selected to adsorb or react with an adsorbed reactant.

In addition, the gases may or may not be premixed. Appropriate valve regulation and mass flow control mechanisms may be used to ensure that the correct gas is delivered during the deposition and plasma treatment phases of the process. The process gas leaves the chamber through an outlet. A vacuum pump (e.g., a mechanical dry pump and/or a turbomolecular pump in one or two stages) draws the process gas out, and a suitable low pressure is maintained within the reactor by a closed-loop controlled flow restriction device (e.g., a throttling valve or a swing valve).

Also shown is a support ring 200 that surrounds an outer region of the base 140. The support ring 200 is configured to be located above a support ring support area that is one step down from the wafer support area at the center of the base 140. The support ring includes an outer edge side of its disk structure (e.g., an outer radius), and a wafer edge side of its disk structure (e.g., an inner radius, which is closest to where the wafer 101 is located). The wafer edge side of the support ring includes a plurality of contact support structures that are configured to lift the wafer 101 when the support ring 200 is lifted by the spider fork 180. The load ring 200 is thus lifted together with the wafer 101 and can be rotated to another workstation in a multi-workstation system, for example. In other embodiments, the chamber is a single-workstation chamber.

FIG. 2 depicts a top view of a multi-station processing tool in which four processing stations are provided. This top view is a top view of the lower chamber 102b (the upper chamber 102a is removed for illustration), wherein the four stations are accessed by spider forks 226. Each spider fork (or fork) includes first and second arms, each of which is positioned around a portion of each side of the base 140. In this view, the spider forks 226 are drawn in dashed lines to indicate that they are below the carrier ring 200. The spider fork 226 using the engagement and rotation mechanism 220 is configured to simultaneously lift and elevate the carrier rings 200 from the workstations (i.e., from the bottom surface of the carrier rings 200), and then rotate at least one or more of the workstations before lowering the carrier rings 200 to the next position (where at least one of the carrier rings supports the wafer 101) so that further plasma processing, processing and/or film deposition can occur on each wafer 101.

3 shows a schematic diagram of an embodiment of a multi-station processing tool 300 having an inbound load lock 302 and an outbound load lock 304. A robot 306 under atmospheric pressure is configured to move substrates from a cassette (loaded via a pod 308) into the inbound load lock 302 through an atmospheric port 310. The inbound load lock 302 is coupled to a vacuum source (not shown) so that the inbound load lock 302 can be evacuated when the atmospheric port 310 is closed. The inbound load lock 302 also includes a chamber transfer port 316 that interfaces with the processing chamber 102b. Thus, when the chamber transfer port 316 is opened, another robot (not shown) may move the substrate from the inbound load lock 302 to the base 140 of the first processing station for processing.

The depicted processing chamber 102b includes four processing stations, numbered 1 through 4 in the embodiment shown in FIG3. In some embodiments, the processing chamber 102b can be configured to maintain a low pressure environment so that substrates can be transferred between processing stations without experiencing vacuum break and/or air exposure using the carrier ring 200. Each processing station depicted in FIG3 includes a processing station substrate support (shown as 318 for station 1) and a process gas delivery line inlet.

FIG. 3 also depicts spider forks 226 used to transfer substrates within the processing chamber 102b. The spider forks 226 rotate and allow wafers to be transferred from one workstation to another. The transfer occurs by enabling the spider forks 226 to lift the carrier ring 200 from the outer bottom surface to lift the wafer and rotate the wafer and carrier ring together to the next workstation. In one configuration, the spider forks 226 are made of a ceramic material to withstand high levels of heat during processing. Lifting Pad and Base Configuration for Wafer Positioning

FIG. 4 depicts a substrate processing system including a lift pad and pedestal arrangement 400 according to one embodiment of the present disclosure, wherein a lift pad 430 is sized to substantially match a wafer (not shown) disposed thereon. In some embodiments, the lift pad 430 is sized to substantially allow integration with a carrier ring assembly. The lift pad and pedestal arrangement 400 may be implemented in the systems of FIGS. 1-3 including multi-station and single-station processing tools.

The lift pad and base arrangement 400 includes a lift pad 430 controlled by a lift pad control 455 and a base 140' controlled by a base control 450. A central axis 510' is coupled to the base 140', and a pad axis 560 is coupled to the lift pad 430. The base control 450 controls the movement of the central axis 510' to induce movement of the base 140'. For example, the base control 450 controls the movement of the base 140' (e.g., up and down along the central axis) during pre-processing, processing, and post-processing sequences. The lift pad control 455 controls the movement of the lift pad axis 560 to induce movement of the lift pad 430. For example, the lift pad control 455 controls the movement of the lift pad 430 (e.g., up and down movement along and rotation about the center axis 471) during pre-processing, processing, and post-processing sequences. In particular, the lift pad and base arrangement 400 provides for rotation of the wafer with significantly reduced hardware rotation characteristics compared to rotating the entire base 140'. That is, because the base 140' and/or chamber (not shown) remain stationary relative to the lift pad 430 when rotating the wafer, asymmetries based on the base and chamber are both filtered out, thereby significantly reducing the hardware base and chamber characteristics that are exhibited on the wafer during processing. That is, non-uniformities caused by pedestal features can be distributed symmetrically across the wafer during wafer processing by rotating the wafer using the lift pad without rotating the pedestal.

The lift pad and pedestal arrangement 400 includes a plurality of heating elements 470 for directly heating the pedestal 140' (e.g., by conduction) and, when disposed on the pedestal 140', indirectly heating the lift pad 430. Additionally, in some process modules, the lift pad and pedestal arrangement 400 optionally includes a plurality of cooling elements 480 for cooling the pedestal 140'.

As previously described, the lift pad and base arrangement 400 includes a center column, which is shown as including a coaxial lift pin assembly 415 having a plurality of lift pins controlled by the lift pin control 122. The lift pins are used, for example, to lift the wafer from the lift pad 430 and base 140' to allow the end effector to pick up the wafer during a wafer transfer sequence, and to lower the wafer after it has been placed by the end effector.

The lifting pad and base arrangement 400 includes a telescoping bladder 420. The telescoping bladder 420 is coupled to the lifting pin assembly 415, the base, or the lifting pad, respectively, and is configured for movement of the lifting pin, the base, or the lifting pad. In addition, the lifting pad and base arrangement 400 includes a rotary motor 427 in a belt-pulley arrangement. In addition, a ferromagnetic seal 425 facilitates rotation of the lifting pad 430 in a vacuum environment.

In one embodiment, the wafer-sized lift pad 430 is compatible with an electrostatic chuck (ESC). The ESC 570 is configured to include electrodes biased to a high voltage to induce an electrostatic holding force to hold the wafer in place when the ESC 570 is activated. In addition, in one embodiment, the lift pad and base arrangement 400 includes a compliant shaft 435 that promotes a uniform gap between the lift pad 430 and the base 140', particularly when the lift pad 430 is moved to be placed on the base 140'.

As shown in Figure 4, in one embodiment, a ball screw 437 (e.g., left-handed) is configured to drive the lift pins relative to the base 140' during one of the processing sequences. For example, the ball screw 437 can be engaged during a wafer transfer sequence to extend the lift pins for wafer transfer when the base 140' moves near or at a bottommost position. The ball screw 443 (e.g., right-handed) is used to move the base along the center axis in the Z direction. For example, the ball screw 443 is configured to drive the base 140' in the Z direction along the center axis using the Z motor 445. In addition, a short-stroke coupling mechanism 440 is shown.

Figure 5A is a cross-sectional view of the substrate processing system of Figure 4 according to one embodiment of the present disclosure. In particular, Figure 5A depicts a lift pad and pedestal arrangement 400, wherein the lift pad 430 is sized to substantially match a wafer (not shown).

For illustration purposes only, the base 140' is formed in three parts to accommodate the plurality of heating elements 470 and the plurality of cooling elements 480 during manufacturing. It is understood that the base 140' is considered as a component and can be formed using any suitable manufacturing process.

As shown in FIG5A , the base 140′ and the lift pad 430 are at a height that allows the lift pins 557 to extend for wafer transfer. Each of the lift pins 557 is coupled to a corresponding lift pin support 555 for movement, wherein the movement of the lift pin support 555 is controlled by the lift pin control 122. In one embodiment, the base 140′ is at a bottommost position along the center axis 471 along its Z direction of travel.

As described above, the base control unit 450 controls the movement of the central axis 510'. Since the base 140' is coupled to the central axis 510', the movement of the central axis 510' is transferred to the base 140'. In addition, as described above, the lift pad control unit 455 controls the movement of the pad axis 560. Since the lift pad 430 is coupled to the pad axis 560, the movement of the pad axis 560 is transferred to the lift pad 430.

FIG. 5B is a cross-sectional view of the substrate processing system of FIG. 4 showing an assembly 500B according to one embodiment of the present disclosure, the assembly 500B including the lift pad and pedestal arrangement 400 previously described in FIGS. 4 and 5A. The lift pad 430 is sized to substantially match a wafer (not shown). In yet another embodiment, the diameter of the lift pad 430 is sized to accommodate a carrier ring (not shown). The lift pad and pedestal arrangement 500B provides improved film uniformity by rotating the wafer using the lift pad without rotating the pedestal during deposition processes (e.g., PECVD, ALD, etc.) in single-station and multi-station systems to filter out azimuthal non-uniformities due to chamber and pedestal asymmetries. In particular, the rotating lift pad 430 is much thinner than the entire pedestal 140', and therefore the rotational features of the lift pad 430 are much less of asymmetric hardware contributions to non-uniformity than the rotational features of the pedestal 140' including the heater element 470 and the cooling element 480. That is, non-uniformity caused by the pedestal features can be distributed symmetrically across the wafer during wafer processing by rotating the wafer using the lift pad and without rotating the pedestal.

In assembly 500B, base 140' includes a base top surface 533 extending from a central axis 471 of base 140'. Top surface 533 may include one or more recesses to provide an interface between base 140' and lift pad 430, such as a recess in the center of top surface 533, centered about central axis 471 and configured to facilitate coupling between pad shaft 560 and lift pad 430, and a recess forming outer edge 509. Although base 140' may be described as having a generally circular shape when viewed from above and extending to the base diameter, the footprint of base 140' may vary from a true circle to accommodate different features, such as a load ring mount and end effector access, etc.

As shown, the base 140' is connected to an actuator 515 configured to control the movement of the base 140'. In particular, the base control portion 450 is coupled to the actuator 515 to control the movement of the base 140'. That is, the central axis 510' is coupled to the actuator 515 and the base 140', so that the central axis 510' extends between the actuator 515 and the base 140'. The central axis 510' is configured to move the base 140' along the central axis 471. In this regard, the movement of the actuator 515 is converted into the movement of the central axis 510', which is in turn converted into the movement of the base 140'.

In addition, for illustrative purposes only, the base 140' is shown as having three parts 140a', 140b', and 140c'. For example, the base 140' can be formed in three parts to structurally accommodate a plurality of heating elements 470 and/or a plurality of cooling elements 480 during manufacturing. As previously disclosed, it is understood that the base 140' is considered to be a component and can be formed using any suitable manufacturing process.

In assembly 500B, lift pad 430 includes a pad top surface 575 extending from center axis 471. In one embodiment, pad top surface 575 extends to pad diameter 577. Lift pad 430 includes pad bottom surface 543 configured to rest on base top surface 533. Furthermore, pad top surface 575 is configured to support a wafer when the wafer is placed thereon.

In addition, the lift pad 430 is electrostatic chuck (ESC) compatible, as previously described. For example, the ESC assembly 570 is disposed below the pad top surface 575. The electrostatic chuck assembly 570 prevents wafer movement due to chamber flow disturbances and maximizes wafer contact with the chuck (i.e., lift pad top surface 575). The lift pad 430 combines the benefits of a full wafer ESC for wafers of similar size resulting in minimal wafer backside deposition. In addition, the full wafer ESC does not need to be declamped for twisting and/or rotation.

As shown, the lift pad 430 is connected to an actuator 515 configured to control the movement of the lift pad 430. The lift pad control unit 455 is coupled to the actuator 515 to control the movement of the lift pad 430. That is, the pad shaft 560 is coupled to the actuator 515 and the base 140' so that the pad shaft 560 extends between the actuator 515 and the base 140'. The pad shaft 560 is configured within a central shaft 510' connected to the base 140'. In particular, the pad shaft 560 is configured to move the base 140' along the central axis 471. In this regard, the movement of the actuator 515 is converted into the movement of the pad shaft 560, which is in turn converted into the movement of the lift pad 430. In one embodiment, the actuator 515 controls the movement of both the lift pad 430 and the base 140'.

9A-9C , the pad shaft 560 is configured to separate the lift pad 430 from the base 140′. For example, the lift pad 430 is configured to move upward relative to the base top surface 533 along the central axis 471 when the base 140′ is in the upward position, so that the lift pad 430 is separated from the base top surface 533 by a process rotational displacement to provide for the rotation of the lift pad 430. In one embodiment, the lift pad 430 moves upward relative to the base top surface 533 when the base 140′ has reached the highest upward position. In addition, when the lifting pad 430 is separated from the base top surface 533, the lifting pad 430 is configured to rotate between at least a first angular orientation and a second angular orientation (e.g., between 0 degrees and 180 degrees) relative to the base top surface 533 of the base 140'. The pad shaft 560 is also configured to lower the lifting pad 430 to be placed on the base 140'. In particular, the flexible coupler 435 (shown in Figure 5C) is disposed within the pad shaft 560 and is configured to evenly place the lifting pad 430 on the base 140'.

In preparation for the rotation of the lift pad 430, in one embodiment, the lift pad 430 is moved upward relative to the base 140'. That is, the lift pad 430 is configured to move upward relative to the base top surface 533 along the central axis 471 when the base 140' is in an upward position (e.g., a highest upward position) during wafer processing, so that the lift pad 430 is separated from the base top surface 533 by a process rotation displacement 940 (see FIG. 9B), and the wafer disposed on the lift pad 430 is also separated from the base 140'. In particular, when the lift pad 430 is separated from the base 140', the lift pad 430 is configured to rotate relative to the base top surface 533 between at least a first angular orientation and a second angular orientation. This rotation reduces the effect of hardware features of the pedestal during processing and also reduces the effect of hardware features of the chamber during processing. In addition, the focus ring (not shown) does not rotate with the wafer, thereby reducing hardware features on the wafer during processing.

Assembly 500B includes a lift pin assembly including a plurality of lift pins 557. For purposes of illustration, base 140' and lift pad 430 are at a height that allows lift pins 557 to extend for wafer transfer in accordance with one embodiment of the present disclosure. In particular, lift pins 557 extend from lift pad 430 through a plurality of base shafts 518 disposed in base 140' and through a plurality of lift pad shafts 519 in lift pad 430 in such a manner that an arm (not shown) of an end effector carrying a wafer (with or without a carrier ring) can be moved to a position for transferring a wafer to lift pins 557 or for receiving a wafer from lift pins 557. The corresponding base shafts 518 and pad shafts 519 are aligned and configured to receive corresponding lift pins 557. As shown, one or more lift pin shafts and corresponding lift pins can be configured in the lift pin assembly to lift and place or remove the wafer during wafer transfer. As shown, each lift pin 557 is coupled to a corresponding lift pin support 555 to achieve movement. The lift pin support 555 is coupled to the lift pin actuator 550. In addition, the lift pin control unit 122 controls the movement of the lift pin actuator 550 to achieve the movement of the lift pin 557.

The lift pin support 555 can have any shape (e.g., an annular washer, arms extending from an annular base, etc.). In particular, during operation of the lift pin assembly, lift pins 557 are attached to the lift pin support 555 and are configured to move within the lift pin shafts to raise the wafer above the lift pad top surface 575 and/or lower the wafer to rest on the pad top surface 575 during wafer handling and processing.

FIG. 5C is a diagram of an interface between a lift pad 430 and a base 140' that includes a pad gap setting minimum contact area (MCA) to control and/or mechanically set the gap, particularly during a processing sequence, according to an embodiment of the present disclosure. This results in uniform temperature and impedance control of the pad. The interface shown in FIG. 5C is an example of the interface between the lift pad and base shown in FIGS. 5A and 5B.

It is advantageous for deposition processes that the gap between the lift pad 430 and the pedestal 140' is uniform and small. For example, PECVD and ALD processes may exhibit non-uniform characteristics due to, for example, temperature and plasma impedance. Both of these factors are sensitive to the gap between the wafer and the pedestal. Minimizing the size of the gap and controlling the uniformity of the gap across the lift pad and pedestal configuration reduces characteristics due to temperature and plasma impedance.

In particular, the small gap allows for low impedance coupling of radio frequency (RF) energy between the lift pad 430 and the base 140'. In addition, the small gap provides a lower thermal resistance, thereby allowing heating and/or cooling to be easily transferred from the base 140' to the lift pad 430. Furthermore, the uniform gap between the lift pad 430 and the base 140' ensures uniform heat transfer and uniform RF coupling.

As shown, the base top surface 533 includes a plurality of pad supports 595 (e.g., pad gap settings MCA) defined thereon, wherein the pad supports are configured to support the lift pad 430 at a pad support height above the base top surface 533. Portions 140a' and 140b' of the base 140' are shown in FIG5C. As previously described, the pad supports 595 provide a uniform and small gap between the lift pad 430 and the base 140', thereby ensuring uniform heat transfer and uniform RF coupling between the lift pad 430 and the base 140'. More particularly, the bottom surface 543 of the lift pad 430 is configured to rest on the plurality of pad supports 595 of the base 140'. For example, the base 140' and the lift pad 430 can be configured in a processing position (e.g., when performing plasma processing, treatment and/or film deposition), or in a pre-coating position, such that the lift pad 430 is placed on a plurality of pad supports 595. In addition, the lift pad 430 is configured to move with the base 140' when the base 140' is placed on the pad supports 595. The pad supports can be conductive for DC, low frequency, and RF transmission.

FIG6 depicts a substrate processing system including a lift pad and pedestal arrangement 600 according to one embodiment of the present disclosure, wherein the lift pad 630 is smaller than a wafer (not shown). The lift pad and pedestal arrangement 600 may be implemented in the system of FIGS. 1-3 including multi-station and single-station processing tools.

The lift pad and pedestal arrangement 600 includes a lift pad 630 controlled by a lift pad control 455 and a pedestal 140″ controlled by a pedestal control 450. As previously described, the pedestal control 450 controls movement of the pedestal 140″ along the central axis 471′, while the lift pad control 455 controls movement (e.g., upward, downward, and rotation) of the lift pad 630 about the central axis 471′. The lift pad and pedestal arrangement 600 provides for rotation of a wafer (not shown) by the lift pad 630 with significantly reduced hardware rotation features when compared to processing tools with or without pedestal rotation.

The lift pad and pedestal configuration 600 includes a small lift pad 630 that is smaller than the wafer footprint. The lift pad and pedestal configuration 600 may be suitable for some deposition processes when ESC is not selected. In this case, the small lift pad 630 is preferred because it allows the minimum contact area (MCA) of the pedestal supporting the wafer during processing to not rotate with the wafer. In this case, the wafer gap nominally does not rotate with the wafer, which reduces exposure to hardware asymmetries. In addition, the smaller lift pad 630 also provides a further benefit because it provides less mechanical stress on the system because less mass needs to be rotated.

The lift pad and pedestal arrangement 600 includes a plurality of heating elements 470' and thermocouples 607 included in the pad shaft 560' of the lift pad 630 to match the temperature at the surface of the lift pad 630 to the surface of the pedestal 140'. Cooling elements in the pedestal 140' may be included in some process modules.

In one embodiment, although not shown, the lift pad and base arrangement 600 optionally includes a lift pin assembly having a plurality of lift pins controlled by the lift pin control 122 for use in wafer transfer as described above. The flange 605 is included in a coaxial lift pin assembly (not shown). In another embodiment, a small lift pad 630 may be used to provide the lift pin functionality, eliminating the need for a lift pin assembly, and thus providing cost and packaging advantages.

The lift pad and base arrangement 600 includes a bladder 420', each of which is coupled to an optional lift pin assembly, base 140", or lift pad 630 and configured for movement of the lift pin assembly, base 140", or lift pad 630, respectively. In addition, the lift pad and base arrangement 600 also includes a rotary motor in a belt-pulley arrangement (not shown) similar to that shown in FIG. 4. A ferromagnetic seal 425' facilitates rotation of the lift pad 630 in a vacuum environment.

In addition, the Z motor 445' is configured to drive the base 140'' in the Z direction along the central axis 471'. In addition, the sliding member 603 driven by the coupling mechanism is attached to the base and the central axis 510'', and is attached to the ball screw attached to the Z motor 445', all of which are used to promote the movement of the base 140'' along the central axis 471'.

FIG. 7A is a perspective view of the substrate processing system of FIG. 6 according to one embodiment of the present disclosure. In particular, FIG. 7A includes a lift pad and base configuration 600, wherein the lift pad 630 is smaller than the wafer (not shown). As shown in FIG. 7A, the base 140″ and the lift pad 630 are shown in a position and/or height that allows wafer processing.

As described above, the base control unit 450 controls the movement of the central axis 510''. Because the base 140'' is coupled to the central axis 510'', the movement of the central axis 510'' is converted to the base 140''. In addition, as described above, the lifting pad control unit 455 controls the movement of the pad shaft 560'. Because the lifting pad 630 is coupled to the pad shaft 560', the movement of the pad shaft 560' is converted to the lifting pad 630.

The base 140″ of the lift pad and base arrangement 600 includes a base top surface 720 extending from a central axis 471′ of the base 140″. A plurality of wafer supports 760 are disposed on the top surface 720. In addition, a raised edge 710 is disposed on an outer edge of the base top surface 720, wherein the raised edge 710 is configured to block lateral movement of a wafer placed on the base 140″.

FIG. 7B is a cross-sectional view of the substrate processing system of FIG. 6 showing an assembly 700B including the lift pad and pedestal arrangement 600 previously described in FIGS. 6 and 7A according to one embodiment of the present disclosure. The lift pad 630 is smaller than the wafer in size according to one embodiment of the present disclosure. For illustrative purposes only, the pedestal 140″ and lift pad 630 are shown in a position and/or height that allows wafer processing. The lift pad and pedestal arrangement assembly 700B provides improved film uniformity by rotating the wafer using the lift pad without rotating the pedestal during deposition processes (e.g., PECVD, ALD, etc.) in single workstation and multi-workstation systems to filter out azimuthal non-uniformities caused by chamber and pedestal asymmetries. In particular, the rotating lift pad 630 is much smaller and thinner than the entire pedestal 140″, and therefore the rotational features of the lift pad 630 are much less of an asymmetric hardware contribution to non-uniformity than the rotational features of the pedestal 140″ including the heating element 470′. That is, non-uniformity caused by the pedestal features can be distributed symmetrically across the wafer during wafer processing by rotating the wafer using the lift pad and without rotating the pedestal.

In assembly 700B, the base 140'' includes a base top surface 720 extending from a central axis 471' of the base 140''. The base top surface 720 is configured to support a wafer when the wafer is placed thereon. The top surface 720 may include one or more recesses to provide an interface between the base 140'' and the lift pad 630, such as a recess 705 configured to facilitate coupling between the pad shaft 560' and the lift pad 630, and a recess forming an outer edge 710. Although the base 140'' may be described as having a generally circular shape when viewed from above and extending to the base diameter, the footprint of the base 140'' may vary from a circle to accommodate different features, such as a load ring support and end effector access.

As shown, the base 140'' is connected to an actuator 515' configured to control the movement of the base 140''. In particular, the base control unit 450 is coupled to the actuator 515' to control the movement of the base 140''. In particular, the central axis 510'' is coupled to the actuator 515' and the base 140'' so that the central axis 510'' extends between the actuator 515' and the base 140''. The central axis 510'' is configured to move the base 140'' along the central axis 471'. In this regard, the movement of the actuator 515' is converted into the movement of the central axis 510'', which is in turn converted into the movement of the base 140''.

In one embodiment, the pedestal top surface 720 includes a plurality of wafer supporters (not shown) defined thereon, wherein the wafer supporters are configured to support a wafer 590 at a wafer support height above the pedestal top surface 720. The wafer supporters provide a uniform and small gap between the pedestal 140″ and any wafer 590 disposed thereon.

The base 140″ includes a recess 705 disposed at the center of the base top surface 720 and extending from the central axis 471′, the recess 705 having a recess height, and wherein the recess 705 has a recess bottom surface 706. That is, the recess 705 is located on a central portion of the base top surface 720. In one embodiment, the recess bottom surface 706 includes a plurality of pad supports defined thereon, wherein the pad supports (e.g., MCAs) are configured to support the lift pad 630 at a pad support height above the recess bottom surface 706. In another embodiment, as further described with respect to FIG. 7F , the MCAs are disposed on the bottom surface of the lift pad 630.

In addition, for illustrative purposes only, the base 140'' is shown as having two parts 140a'' and 140b''. For example, the base 140'' can be formed in two parts to accommodate a plurality of heating elements 470' and/or a plurality of cooling elements (not shown) on the structure during manufacturing. As previously disclosed, it is understood that the base 140'' is considered to be a component and can be formed using any suitable manufacturing process.

In assembly 700B, lift pad 630 includes lift pad top surface 775 extending from center axis 471′ to pad diameter 777. When lift pad 630 is positioned within recess 705, lift pad 630 is configured to rest on recess bottom surface 706, wherein recess 705 is configured to receive lift pad 630. In particular, lift pad top surface 775 is below wafer 590 when wafer 590 is positioned on wafer support of pedestal 140″, such as in a processing position (e.g., when performing plasma processing, treatment, and/or film deposition). That is, when the pad bottom surface 632 of the lift pad 630 is placed on a plurality of pad supports (e.g., MCA 745), the lift pad top surface 775 is located below the wafer support height. In addition, the lift pad 630 is configured to move with the base 140'' when the base 140'' is placed on the pad support.

As shown, the lift pad 630 is connected to an actuator 515' configured to control the movement of the lift pad 630. For example, the lift pad control unit 455 is coupled to the actuator 515' to control the movement of the lift pad 630. In particular, the pad shaft 560' is coupled to the actuator 515' and the base 140'' so that the pad shaft 560' extends between the actuator 515' and the base 140''. The pad shaft 560' is configured within a central shaft 510'' connected to the base 140''. In particular, the pad shaft 560' is configured to move the lift pad 630 along the central axis 471'. In this regard, the motion of the actuator 515' is converted into the motion of the pad 560', which in turn is converted into the motion of the lift pad 630. In one embodiment, the actuator 515' controls the motion of both the lift pad 630 and the base 140'.

Specifically, as will be described more fully below with respect to Figures 10A-10D, the pad shaft 560' is configured to separate the lift pad 630 from the base 140' for rotation of the lift pad. For example, when the base 140'' is in the upward position, the lift pad 630 is configured to move upward along the central axis 471' relative to the base top surface 720 so that the lift pad 630 is separated from the base top surface 720 by a process rotational displacement for rotating the lift pad 630. The pad shaft 560' is also configured to lower the lift pad 630 to be placed on the base 140''. In one embodiment, in preparation for the lift pad to rotate, the lift pad 630 moves upward relative to the base 140''. That is, when the base 140″ is in the upward position, the lifting pad 630 is configured to move upward along the central axis 471′ relative to the base top surface 720, so that the lifting pad 630 is separated from the base top surface 720 by a process rotation displacement 1040 (see Figures 10B and 10C), and the wafer configured on the lifting pad 630 is separated from the base 140″. In one embodiment, the base 140″ is in the highest upward position during the rotation of the lifting pad 630. In particular, when the lifting pad 630 is separated from the base 140″, the lifting pad 630 is configured to rotate between at least a first angular orientation and a second angular orientation (for example, between 0 degrees and 180 degrees) relative to the base top surface 720. This rotation reduces the impact of the base's hardware features during processing, and also reduces the impact of the chamber's hardware features during processing.

In other embodiments, the lift pad 630 provides lift pin functionality to raise and lower the wafer during wafer transfer and processing. Specifically, when the base is in the bottom-most downward position, the lift pad 630 is configured to move upward relative to the center base top surface 720 so that the lift pad 630 is separated from the center base top surface 720 by a displacement large enough to allow the arm of the end effector to enter.

As shown in FIG. 7B , the base 140″ of the lift pad and base arrangement 600 includes a raised edge 710 disposed on the outer edge of the base top surface 720, wherein the raised edge 710 is configured to block lateral movement of a wafer placed on the base 140″. That is, the edge 710 is one step above the base top surface 720 and at a height sufficient to block the movement of the wafer. For example, when the wafer is placed on the base top surface 720, the raised edge 710 forms a groove that blocks the lateral movement of the wafer.

FIG. 7C shows a cross-sectional view of the substrate processing system of FIG. 6 including an assembly 700C of a lift pad and base configuration 600′ based on the configuration previously described in FIGS. 6, 7A, and 7B, wherein the lift pad 630 is smaller than the wafer, according to one embodiment of the present disclosure. The lift pad and base configuration 600′ includes a base 140′″ and a lift pad 630. More specifically, the lift pad and base configuration 600′ of FIG. 7C is similar to the lift pad and base configuration 600 of FIG. 7B and provides the same benefits and advantages previously described with respect to FIG. 7B (e.g., improved fill uniformity during a deposition process). That is, non-uniformities caused by base features can be distributed symmetrically across the wafer during wafer processing by rotating the wafer using the lift pad and without rotating the base. However, the lift pad and base arrangement 600' also includes a lift pin assembly configured for delivery of a corresponding wafer (e.g., wafer 590).

The lift pin assembly of assembly 700C includes a plurality of lift pins 557'. For purposes of illustration, the base 140''' and lift pad 630 are used for wafer delivery at a height that allows the lift pins 557' to extend in accordance with one embodiment of the present disclosure. In particular, the lift pins 557' extend from a plurality of base shafts 518' that translate from the center axis 471' and are disposed in the base 140''' in such a manner that an arm (not shown) of an end effector carrying a wafer (with or without a carrier ring) can be moved to a position for delivering a wafer to the lift pins 557' or for receiving a wafer from the lift pins 557'. The corresponding base shaft 518' is configured to receive a corresponding lift pin 557'. As shown, one or more base shafts 518' and corresponding lift pins 557' may be configured within the lift pin assembly to lift and place or remove wafers during wafer transfer. As shown, each lift pin 557' is coupled to a corresponding lift pin support 555' and is configured to move within the base shaft 518' to lift the wafer above the base top surface 720 and/or lower the wafer to the base top surface 720 during wafer transfer and processing. The lift pin support 555' is configured to move parallel to the center axis 471' relative to the base top surface 720. In addition, the lift pin support 555' is coupled to the lift pin actuator 550'. In addition, the lift pin control unit 122 previously introduced controls the movement of the lift pin actuator 550' to achieve the movement of the lift pins 557'. The lift pin support 555' can have any shape (e.g., an annular washer, an arm extending from an annular base, etc.).

7D is a cross-sectional view of a lift pad to pedestal interface in the substrate processing system of FIG. 6 including the lift pad and pedestal configuration 600 or 600' of FIGS. 7A-7C , wherein the lift pad is smaller than the wafer, according to one embodiment of the present disclosure.

The high temperature bearing 755 is disposed within the washer shaft 560' and is configured to uniformly position the lift pad 630 within the recess 705 of the base 140'' or 140'''. To handle the high temperatures, the wear resistant surface is preferably made of a hard, chemically compatible material such as sapphire. The bearing centering is insensitive to the relative thermal expansion of the bearing elements, shaft, and base materials. In one embodiment, the tapered clamping surface of the sapphire bearing ring can be spring loaded using an assembly of load distribution washers, spring washers, and retaining rings of materials suitable for high temperature and corrosive operations. The bearing is clamped at its center position with minimal energy and remains centered under temperature changes. The sapphire contact ring prevents dents in softer base materials.

In particular, the interface between the lift pad 630 and the base 140''/140''' is shown and includes a pad gap setting MCA to control and/or mechanically set the gap, particularly during a processing sequence. For example, Figure 7D shows sapphire balls 740 and 745 (e.g., MCA) pressed into the lift pad 630. In particular, the balls 740 and 745 protrude slightly above the corresponding surface of the operating system on the order of a few millimeters at process temperatures. The sapphire balls operate to contact the base 140''/140''' with a minimum contact area to minimize heat transfer by contacting poor heat conducting materials. In addition, the sapphire contact ring prevents dents in softer base materials.

For example, FIG. 7E is a perspective view of the top surface 631 of the lift pad 630 shown in FIG. 7D including the MCA 740 according to one embodiment of the present disclosure. In one embodiment, the wafer-based MCA 740 is disposed 0.002 inches above the top surface 631 such that when the lift pad 630 is placed on the recess bottom surface 706, the pad top surface 631 is below the wafer support height. In one embodiment, when the lift pad 630 is placed on the pedestal 140''/140''', the wafer-based MCA 740 does not contact the wafer 590 because the separate pedestal wafer support (e.g., MCA) located on the pedestal top surface 720 is about 0.002 inches higher. The wafer support disposed on the base top surface 720 of the base 140''/140''' is configured to support the wafer 590 when the wafer 590 is placed thereon at a wafer supporting height on the top surface 720.

Additionally, FIG. 7F is a perspective view of the bottom surface 632 of the lift pad 630 shown in FIG. 7D including the MCA 745 according to one embodiment of the present disclosure. In one embodiment, the wafer reference MCA 745 is 0.004 inches above the bottom surface 632. This ensures a uniform, repeatable gap between the lift pad 630 and the base 140''/140''' to provide a uniform, repeatable thermal resistance to the base 140''/140'''. In one embodiment, the MCA 745 works in conjunction with a plurality of pad supports (not shown) disposed on the recess bottom surface 706, which are configured to support the lift pad 630 at a pad support height on the recess bottom surface 706.

FIG. 8 is a flow chart 800 depicting a method for operating a processing chamber configured for depositing a film on a wafer, wherein the method provides for rotating the wafer without rotating the pedestal during processing within the processing chamber, which advantageously filters out both chamber and pedestal asymmetries, according to an embodiment of the present disclosure. In an embodiment of the present disclosure, flow chart 800 is implemented within the system and lift pad and pedestal configuration of FIGS. 1-7 . The operations in flow chart 800 are applied to lift pad and pedestal configurations of wafer size as shown in FIGS. 4 and 5A-5C of the embodiments, and in other embodiments, to lift pad and pedestal configurations including lift pads smaller than the wafer, as shown in FIGS. 6 and 7A-7F .

At operation 805, the method includes moving a lift pad and base configuration to a bottom-facing position to receive a wafer. In one embodiment, the base is in its bottom-most downward position. In a lift pad and base configuration that includes a lift pin assembly, the lift pins may be extended for wafer delivery. In a lift pad and base configuration that does not include a lift pin assembly, the lift pad (e.g., smaller than the wafer) may be separated from the base top surface by a displacement large enough to allow the arm of the end effector to enter for wafer delivery. At operation 810, a wafer is placed on an assembly including a lift pad and base configuration, wherein the lift pad is configured to be placed on the base. For example, this may involve placing the wafer on extended lift pins, or placing the wafer on an extended lift pad. The lift pins or lift pad are lowered so that the wafer rests on a wafer support on the top surface of the base, the top surface of the lift pad, or the surface of the ESC chuck.

The movement of the base is controlled so that the base moves up and down along the center axis of the base. In one embodiment, the coupling mechanism converts the movement of the base to the lift pad in the lift pad and base configuration. For example, after delivering the wafer, the lift pad and base configuration is moved to a processing position in operation 820. In the processing position, the lift pad is placed on the base as described above. In addition, the lift pad is in a first orientation relative to the base and/or chamber. The first orientation can be arbitrary. For example, both the lift pad and the base can be configured in an angle orientation of 0 degrees within the chamber.

At operation 825, the method includes processing the wafer in the first orientation for a first number of processing cycles. For example, deposition of one or more films may be performed using an atomic layer deposition (ALD) process, also known as atomic layer chemical vapor deposition (ALCVD). ALD produces very thin films that are highly conformal, smooth, and have excellent physical properties. ALD uses volatile gases, solids, or vapors that are sequentially introduced (or pulsed) onto a heated substrate. In an ALD cycle, four operations are performed and may be defined as an A-P-B-P sequence. In step A, a first precursor is introduced as a gas that is absorbed (or adsorbed) into the substrate. In step P, which follows step A, the reactor chamber is purged of the gaseous precursors. In step B, a second precursor is introduced as a gas, which reacts with the absorbed precursor to form a monolayer of the desired material. In step P, which follows step B, the reactor chamber is again purged of the gaseous second precursor. By adjusting this A-P-B-P sequence, the film produced by ALD is deposited a monolayer at a time by repeatedly switching the sequential flow of two or more reactive gases on the substrate. In this way, the thickness of the film can be adjusted depending on the number of cycles performed of the A-P-B-P sequence. The first number of cycles can be defined as a value X. To illustrate embodiments of the present invention that disclose a lift pad and pedestal configuration that is capable of rotating a wafer during processing within a processing chamber without rotating the pedestal while advantageously filtering out both chamber and pedestal asymmetries, the X number of cycles may be 50 cycles.

In operation 830, the method includes raising the base to an upward position. In one embodiment, the base is raised to its highest upward position. By moving the base to the upward position, the lift pad is also raised upward relative to the base (e.g., the top surface of the base) so that the wafer disposed on the lift pad is separated from the base. In one embodiment, the coupling mechanism raises the lift pad when the base approaches the top of its travel. That is, the surface contact of the lift pad to the base is broken, which allows the lift pad to rotate freely. In particular, the lift pad is separated from the base by a process rotational displacement (e.g., on the order of 1 mm). In this way, the wafer supported by or disposed on the lift pad is also separated from the base.

At operation 840, the method includes rotating the lift pad relative to the base (e.g., a top surface of the base) when the lift pad is separated from the base. In particular, the lift pad is rotated from a first orientation to a second orientation relative to the base. For example, the second orientation may differ from the first orientation by 180 degrees (e.g., the first orientation is at 0 degrees).

At operation 845, the method includes lowering the lift pad to rest on the base. And, at operation 850, the method includes moving the base and correspondingly the lift pad back to the processing position. In one embodiment, the operations performed at 845 and 850 occur simultaneously through the action of the coupling mechanism, so that by lowering the base back to the processing position, the lift pad is also lowered until the lift pad rests on the base.

At operation 855, the method includes processing the wafer for a second number of processing cycles (e.g., each cycle including an A-P-B-P sequence) with the lift pad in a second orientation relative to the pedestal. The second number of cycles may be defined as a value Y. To illustrate embodiments of the present invention that disclose lift pad and pedestal configurations that can rotate a wafer during processing in a processing chamber without rotating the pedestal to advantageously filter out both chamber and pedestal asymmetries, the number of cycles Y may be 50 cycles.

In this way, the thickness of the film can be adjusted based on the total number of cycles (e.g., X+Y) performed by the A-P-B-P sequence. Because the wafer is also rotated with respect to the pedestal for a second number of cycles, both chamber and pedestal asymmetries are filtered out, which provides improved film uniformity during wafer processing.

In the example provided above, the first number of cycles is X and the second number of cycles is Y, where both X and Y comprise 50 cycles of the total 100 cycles of performing the A-P-B-P sequence. That is, the first number of processing cycles (X) may be half of the total number of cycles performed in the first orientation, and the second number of processing cycles (Y) may also be half of the total number of cycles performed in the second orientation. In this regard, 50 cycles are performed in a first angular orientation (e.g., 0 degrees), and another 50 cycles are performed in a second angular orientation (e.g., 180 degrees).

Although embodiments of the present disclosure are described with reference to first and second orientations, other embodiments are well suited for performing wafer processing using one or more orientations (e.g., 1, 2, 3, etc.). The orientations may be separated by equal angles in one embodiment, or may be separated by unequal angles in another embodiment. In addition, one or more cycles of wafer processing (e.g., ALD, PECVD, etc.) are performed in each direction. The number of cycles performed in each orientation may be equally distributed in one embodiment, or may be unequally distributed in another embodiment. That is, other embodiments are well suited for two or more groups of cycles in two or more opposing angular orientations (e.g., between a lift pad and a base), where each group may include an equal number of processing cycles (e.g., each cycle includes an A-P-B-P sequence) or a different number of processing cycles.

At operation 860, the method includes moving the lift pad and base configuration to a bottom-facing position to remove a wafer from an assembly including the lift pad and base configuration. In one embodiment, the base is in its bottom-most downward position. As previously described, in a lift pad and base configuration that includes a lift pin assembly, the lift pins may be extended for wafer transfer. In a lift pad and base configuration that does not include a lift pin assembly, the lift pad (e.g., smaller than the wafer) may be separated from the base top surface by a displacement large enough to allow the arm of the end effector to enter for wafer transfer. In this regard, the wafer may be removed from the extended lift pins or the extended lift pad using the arm of the end effector.

9A and 9B are diagrams depicting a motion sequence of a lift pad and pedestal configuration according to an embodiment of the present disclosure, wherein the lift pad is sized to approximately match the wafer and includes rotation of the wafer during processing within the processing chamber without rotation of the pedestal, which advantageously filters out both chamber and pedestal asymmetries.

In particular, FIG. 9A shows a wafer-sized lift pad and base configuration 400 first introduced in FIGS. 4 and 5A-5B. The lift pad and base configuration 400 includes a base 140', a lift pad 430, and a lift pin assembly including lift pins 557. In a delivery position, the lift pad and base configuration 400 is configured so that the base 140' is in a bottom-facing position with the lift pad resting on the base. As shown in the dashed circle labeled "A," the lift pins 557 extend from the top surface of the lift pad 430 for wafer delivery. FIG. 9A also shows the lift pad and base configuration 400 in a pre-coating position, where pre-coating and undercoating layers of a film are deposited within a processing chamber prior to processing a wafer. As shown in the dashed circle labeled "B", the lift pad 430 is placed on the pedestal 140'. In addition, the lift pins 557 are configured so that when pre-coating deposition occurs, the tops of the lift pins 557 just fill the holes corresponding to the pad shafts in the lift pad 430, which is a proper position during chamber pre-coating, and there is no wafer on the lift pad and pedestal configuration 400. Figure 9A also shows the lift pad and pedestal configuration 400 in a processing position, where one or more films can be deposited during wafer processing (e.g., PECVD and ALD processes) in single-station and multi-station systems. For example, wafer processing can perform an atomic layer deposition (ALD) process, which is also called atomic layer chemical vapor deposition (ALCVD). ALD produces highly conformal, smooth, very thin films with excellent physical properties. As previously described, four operations are performed in an ALD cycle (e.g., an A-P-B-P sequence). As shown in the dashed circle labeled "C", the lift pad 430 is placed on the base 140' and the lift pin 557 has been retracted to a position within the body of the base 140'. Figure 9A also shows the lift pad and base configuration 400 in a rotational position, wherein the base is in an upward position (e.g., a highest upward position). As shown in the dashed circle labeled "D", the lift pad 430 is separated from the base 140' by a process rotational displacement so that the lift pad can be rotated to a second angular orientation relative to the base 140'.

FIG. 9B provides further detail of FIG. 9A and depicts the motion sequence of the lift pad and pedestal arrangement 400 first described in FIGS. 4 and 5A-5B , wherein the lift pad is sized to approximately match the wafer and includes rotation of the wafer during processing within the processing chamber without rotation of the pedestal, which advantageously filters out both chamber and pedestal asymmetries, according to one embodiment of the present disclosure.

In the delivery position, the lift pad and pedestal arrangement 400 is configured such that the pedestal 140' is in a bottom-facing position with the lift pad 430 disposed on the pedestal 140'. In particular, the lift pad and pedestal arrangement 400 is in a delivery position ready to receive and/or remove wafers such that the bottom of the pedestal 140' is at a height indicated by line 901 within a corresponding chamber. In particular, in one embodiment, the pedestal 140' is at its bottom-most height and is lower than the pre-coating position (where the bottom of the pedestal 140' is at a height indicated by line 902), and the height indicated by line 903 of the associated processing position, and the height indicated by line 904 of the associated rotational position. As shown, the lift pad 430 is disposed on the pedestal 140' as previously described. Additionally, lift pins 557 extend beyond the top surface of lift pad 430, such as in a position to receive a wafer delivered by an end effector arm.

FIG. 9B shows the lift pad and pedestal configuration 400 at a pre-coating height, wherein the bottom of the pedestal 140′ is at the height indicated by line 902 within the corresponding chamber. It is important to note that the pre-coating position can be defined anywhere within the chamber and is not limited to the height indicated by line 902. For example, the pre-coating position can be the same as the processing position, wherein the lift pad and pedestal configuration is configured for wafer processing (e.g., ALD, PECVD, etc.). As shown, the lift pad 430 is placed on the pedestal 140′ as previously described. In addition, the lift pins 557 are configured so that when pre-coating deposition occurs, the tops of the lift pins just fill the holes in the lift pad 430, which is an appropriate position during chamber pre-coating, and there is no wafer on the lift pad and pedestal configuration.

In particular, prior to processing the wafer, a pre-coat and undercoat layer of the film is deposited within the processing chamber. When a carrier ring is included in a lift pad and pedestal arrangement that contacts the wafer, the pre-coat and/or undercoat film may also coat the carrier ring. It is believed that applying a pre-coat layer to the chamber and lift pad and pedestal arrangement (e.g., in contact with a support structure such as an MCA), and optionally a carrier ring having a pre-coat film similar to the film formed on the wafer during processing, improves film formation on the wafer. In this regard, the pre-coat film is formed prior to introducing the wafer onto the lift pad and pedestal arrangement. In addition, the pre-coating and any further undercoating layers of the wafer processing environment are combined to improve the wafer film uniformity. For example, a typical undercoating thickness may be about 3 microns, while the pre-coating thickness is about 0.5 microns.

FIG9B also shows the lift pad and pedestal configuration 400 in a processing position, wherein one or more films may be deposited during wafer processing (e.g., PECVD and ALD processes) in both single-station and multi-station systems. In particular, the pedestal 140′ is at a height within the corresponding chamber indicated by line 903. As shown, the pedestal 140′ is at approximately its highest position or height within the chamber. It is important to note that depending on the chamber and/or the process being implemented, the processing position may be defined at any position and/or height within the chamber and is not limited to the height indicated by line 903. As shown, the lift pad 430 is placed on the pedestal 140′, as previously described. In addition, the lift pins 557 are configured such that the top of the lift pins is within the body of the pedestal 140′, such that the top may also be placed anywhere within the pedestal 140′ or lift pad 430. Additionally, the lift pad 430 is in a first angular orientation relative to the base 140'.

FIG. 9B also shows the lift pad and base configuration 400 in a rotational position, wherein the base is in an upward position. In one embodiment, the bottom of the base 140′ is at the highest elevation within the corresponding chamber, indicated by line 904. The lift pad 430 is separated from the base 140′ by a process rotational displacement 940 (e.g., on the order of 1 mm). In one embodiment, when the base 140′ approaches the top of its travel, the coupling mechanism raises the lift pad 430 so that the lift pad is separated from the top surface of the base by a rotational displacement 940. In particular, when the base 140′ reaches the top of its travel after a specific distance “d” traveled by the base 140′, the lift pad 430 may move a larger distance that is a factor of “d”. For example, when the base 140' reaches the top of its travel, the lift pad 430 is separated from the base 140' by a rotational displacement 940 of two times "d". Thereafter, the lift pad 430 may be rotated, for example, relative to the base 140' from a first angular orientation to a second angular orientation. Thereafter, the lift pad and base arrangement 400 may be returned to the processing station for additional processing cycles, or returned to the delivery position for wafer delivery.

FIG9C is a diagram depicting the orientation of a lift pad 430 of a pedestal 140′ in a lift pad and pedestal arrangement 400 during a first processing sequence, a rotational sequence, and a second processing sequence in accordance with an embodiment of the present disclosure, wherein the lift pad is approximately the size of a wafer. In particular, FIG9C depicts the relative orientation (within a chamber relative to each other and/or relative to a coordinate system 950) of the lift pad 430 and pedestal 140′ when the lift pad and pedestal arrangement 400 is in a processing position for a first number of processing cycles, when the arrangement 400 is in a rotational position, and when the arrangement 400 is in a processing position for a second number of processing cycles.

As shown, during a first number of processing cycles, the lift pad and pedestal arrangement 400 is in a processing position. In particular, both the lift pad 430 and the pedestal 140′ have an angular orientation of 0 degrees relative to a coordinate system 950 within the chamber. Furthermore, the lift pad 430 has a first angular orientation of 0 degrees relative to the pedestal 140′ (i.e., the pedestal 140′ provides the coordinate system).

9C depicts the rotation of lift pad 430 relative to base 140' when lift pad and base arrangement 400 is in a rotated position. In particular, base 140' remains stationary at an angular orientation of 0 degrees (e.g., relative to coordinate system 950) as lift pad 430 rotates from an angular orientation of 0 degrees to 180 degrees. That is, base 140' does not rotate. As shown, lift pad 430 is halfway through its orientation, at an angular orientation of 71 degrees.

Additionally, during the second number of processing cycles, the lift pad and pedestal arrangement 400 is again in the processing position. However, due to the rotation of the lift pad, the pedestal 140' still has an angular orientation of 0 degrees relative to the coordinate system 950 within the chamber, while the lift pad has an angular orientation of 180 degrees. In other words, when processing the first number of cycles, the lift pad 430 has an angular orientation of 0 degrees relative to the pedestal 140', while when processing the second number of cycles, the lift pad 430 has an angular orientation of, for example, 180 degrees relative to the pedestal 140' after the rotation.

FIGS. 10A-10C are diagrams illustrating a motion sequence of a lift pad and pedestal arrangement according to an embodiment of the present disclosure, wherein the lift pad is smaller than the wafer and includes rotation of the wafer during processing within a processing chamber without rotation of the pedestal, which advantageously filters out both chamber and pedestal asymmetries. More specifically, FIG. 10B shows a lift pad and pedestal arrangement 600 first introduced in FIGS. 6 and 7A-7B. FIG. 10C shows a lift pad and pedestal arrangement 600' first introduced in FIG. 7C and additionally includes a lift pin assembly.

In particular, Figure 10A shows a lift pad and base configuration 600 including a base 140'' and a lift pad 630. The lift pad and base configuration 600 is configured such that the lift pad 630 provides a lift motion and eliminates the need for a lift pin assembly. Specifically, in a delivery position, the lift pad and base configuration 600 is configured such that the base 140'' is in a bottom-facing position, wherein the lift pad 630 is separated from the base 140'' by a sufficient displacement for the arm of the end effector to enter. Figure 10A also shows the lift pad and base configuration 600 in a processing position, wherein one or more films can be deposited during wafer processing (e.g., PECVD and ALD processes) in single workstation and multi-workstation systems. FIG. 10A also shows the lift pad and base configuration 600 in a rotational position, wherein the base 140″ is in an upward position (e.g., a highest upward position) and the lift pad 630 is separated from the base 140″ by a process rotational displacement (e.g., 1 mm).

FIG. 10B provides more detail of FIG. 10A and depicts a motion sequence of a lift pad and pedestal arrangement 600 according to one embodiment of the present disclosure, wherein the lift pad is smaller than the wafer and includes rotation of the wafer during processing within the processing chamber without rotation of the pedestal, which advantageously filters out both chamber and pedestal asymmetries.

In the delivery position of the lift pad and pedestal configuration, the bottom of the pedestal 140'' is within the corresponding chamber at the height indicated by line 901. In particular, in one embodiment, the pedestal 140'' is at its bottommost height. In one embodiment, the delivery position is below the pre-coating position indicated by line 902, the processing position indicated by line 903, and the rotation position indicated by line 904. As shown, the lift pad 630 is separated from the pedestal 140'' by a displacement 969 sufficient to allow the end effector arm to deliver (place a wafer on the lift pad 630, or remove a wafer from the lift pad 630), as shown in Figure 10B. In one embodiment, when the base 140'' approaches the bottom of its travel, the coupling mechanism lifts the lift pad 630 so that the lift pad 630 is displaced 969 away from the top surface of the base.

FIG. 10B also shows the lift pad and pedestal configuration 600 in a pre-coating position, where pre-coating and undercoating layers of the film are deposited within a processing chamber prior to processing a wafer. For example, in the pre-coating position, the bottom of the pedestal 140″ is at the height indicated by line 902 within the corresponding chamber. The pre-coating position can be defined anywhere within the chamber and is not limited to the height indicated by line 902. As shown, the lift pad 630 is placed on the pedestal 140″, as previously described.

In the processing position of the lift pad and pedestal arrangement 600, the bottom of the pedestal 140'' is within the corresponding chamber at the height indicated by line 903. In one embodiment, the pedestal 140'' is near its highest position or height within the chamber, however, as previously described, the processing position may be at any height within the chamber depending on the chamber and/or the process being performed. As shown, the lift pad 630 is placed on the pedestal 140''. In addition, the lift pad 630 is in a first angular orientation relative to the pedestal 140''.

In the rotational position of the lift pad and base configuration 600, in one embodiment, the bottom of the base 140'' is at the highest height indicated by line 904 within the corresponding chamber. The lift pad 630 is separated from the base 140'' by a process rotational displacement 1040 (e.g., on the order of 1 mm). In one embodiment, when the base 140'' approaches the top of its travel, the coupling mechanism lifts the lift pad 630 via the pad shaft 560' so that the lift pad 630 is separated from the top surface of the base by a rotational displacement 1040. In one embodiment, when the base 140'' approaches the top of its travel, the coupling mechanism lifts the lift pad 630 so that the lift pad 630 is separated from the top surface of the base by a rotational displacement 1040. For example, when the pedestal 140″ reaches the top of its travel after a particular distance “f” traveled by the pedestal 140″, the lift pad 630 may move a greater distance that is a factor of “f” (e.g., twice “f”). Thereafter, the lift pad 630 may rotate from a first angular orientation to a second angular orientation (e.g., relative to the pedestal 140″), and then return to the processing position for additional processing cycles or return to the transfer position for wafer transfer.

FIG. 10C provides more detail of FIG. 10A and depicts a motion sequence of a lift pad and pedestal arrangement 600′ including a lift pin assembly, wherein the lift pad 630 is smaller than the wafer and includes rotation of the wafer during processing within the processing chamber without rotation of the pedestal 140′″, which advantageously filters out both chamber and pedestal asymmetries, according to one embodiment of the present disclosure. As previously described, the lift pad and pedestal arrangement 600′ includes the lift pad 630, the pedestal 140′″, and the lift pin assembly.

In the delivery position of the lift pad and base configuration 600', the bottom of the base 140''' is at the height indicated by line 901 within the corresponding chamber. In particular, in one embodiment, the base 140''' is at its bottommost height. In one embodiment, the delivery position is below the pre-coating position indicated by line 902, the processing position indicated by line 903, and the rotation position indicated by line 904. As shown, the lift pad 630 is placed on the base 140''' as described above. In addition, the lift pins 557' extend beyond the top surface of the base 140''' and the lift pad 630, for example in a position to receive a wafer delivered by the arm of the end effector or for removing a wafer by the end effector.

FIG. 10C also shows the lift pad and pedestal configuration 600' in a pre-coating position, where pre-coating and undercoating layers of the film are deposited within a processing chamber prior to processing the wafer. For example, in the pre-coating position, the bottom of the pedestal 140''' is at the height indicated by line 902 within the corresponding chamber. The pre-coating position can be defined anywhere within the chamber and is not limited to the height indicated by line 902. As shown, the lift pad 630 is placed on the pedestal 140''', as previously described. Additionally, lift pins 557' are configured so that when pre-coat deposition occurs, the tops of the lift pins exactly fill the holes in lift pad 630, which is the proper position during chamber pre-coating and there is no wafer on the lift pad and pedestal configuration.

In the processing position of the lift pad and base configuration 600', the bottom of the base 140'' is within the corresponding chamber at the height indicated by line 903. As shown, the base 140'' is near its highest position or height within the chamber, although as previously described, the processing position can be at any height within the chamber. As shown, the lift pad 630 is placed on the base 140'', as previously described. In addition, the lift pins 557' are configured so that the tops of the lift pins are within the base 140'', although the tops can be configured anywhere within the base 140''.

In the rotational position of the lift pad and base configuration 600', in one embodiment, the bottom of the base 140''' is at the highest height indicated by line 904 within the corresponding chamber. The lift pad 630 is separated from the base 140''' by a process rotational displacement 1040 (e.g., on the order of 1 mm). In one embodiment, when the base 140''' approaches the top of its stroke, the coupling mechanism lifts the lift pad 630 via the pad shaft 560' so that the lift pad 630 is separated from the top surface of the base by a rotational displacement 1040. In one embodiment, when the base 140''' approaches the top of its stroke, the coupling mechanism lifts the lift pad 630 so that the lift pad 630 is separated from the top surface of the base by a rotational displacement 1040. For example, when the pedestal 140''' reaches the top of its travel after a particular distance "f" traveled by the pedestal 140''', the lift pad 630 may move a greater distance that is a factor of "f" (e.g., twice "f"). Thereafter, the lift pad 630 may rotate from a first angular orientation to a second angular orientation (e.g., relative to the pedestal 140'''), and then return to the processing position for additional processing cycles or return to the delivery position for wafer delivery.

FIG. 10D is a diagram illustrating an orientation of a lift pad 630 relative to a pedestal 140″ in a lift pad and pedestal arrangement 600 or relative to a pedestal 140″ in a lift pad and pedestal arrangement 600′ during a first processing sequence, a rotational sequence, and a second processing sequence, wherein the lift pad 630 is smaller than a wafer. In particular, FIG. 10D illustrates a relative orientation (e.g., relative to each other and/or relative to a coordinate system 1050 within a chamber) of the lift pad 630 and pedestal 140″/pedestal 140″ when the lift pad and pedestal arrangement 600/600′ is in a processing position for a first number of processing cycles, when in a rotational position, or when in a processing position for a second number of processing cycles.

As shown, during a first number of processing cycles, the lift pad and pedestal arrangement 600/600' is in a processing position. In particular, both the lift pad 630 and the pedestal 140''/140''' have an angular orientation of 0 degrees with respect to a coordinate system 1050 within the chamber. Furthermore, the lift pad 630 has a first angular orientation of 0 degrees with respect to the pedestal 140''/140''' (i.e., the pedestal 140''/140''' provides a coordinate system).

Additionally, FIG. 10D depicts the rotation of lift pad 630 relative to base 140″/140″” when lift pad and base arrangement 600/600′ is in a rotated position. In particular, base 140″/140″’ remains stationary at an angular orientation of 0 degrees (e.g., relative to coordinate system 1050) as lift pad 630 rotates from an angular orientation of 0 degrees to 180 degrees. That is, bases 140″ and 140″’ do not rotate. As shown, lift pad 630 is midway through its orientation, at an angular orientation of 71 degrees.

Furthermore, during the second number of processing cycles, the lifting pad and base arrangement 600/600' are again in the processing position. However, due to the rotation of the lifting pad, the base 140''/140''' still has an angular orientation of 0 degrees relative to the coordinate system 1050 within the chamber, while the lifting pad has an angular orientation of 180 degrees. In other words, when processing the first number of cycles, the lifting pad 630 has an angular orientation of 0 degrees relative to the base 140''/140''', and when processing the second number of cycles, the lifting pad 630 has an angular orientation of, for example, 180 degrees relative to the base 140''/140''' after the rotation. Lifting Pad Raising Mechanism

In embodiments of the present disclosure, the lift pad raising mechanism disclosed in FIGS. 11-17 is generally applicable to the lift pad and base configuration previously described in FIGS. 1-10. That is, many embodiments of the disclosed lift pad raising mechanism can be used to separate the lift pad from the base in a lift pad and base configuration including a lift pad having a diameter approximately equal to the wafer diameter and/or a lift pad having a diameter less than the wafer diameter.

FIG. 11A is a perspective view of a substrate processing system including a lift pad and pedestal arrangement 1100, and depicts a short-stroke pad lift mechanism 440-A configured to separate a lift pad (not shown) from a pedestal 140-A, according to one embodiment of the present disclosure. The lift pad and pedestal arrangement 1100 is located within a main frame 1105, wherein the main frame 1105 is placed into (e.g., secured within) a processing chamber. Movement of the pedestal 140-A is provided relative to the main frame, and movement of the lift pad is provided relative to both the main frame 1105 (the lift pad moves with the pedestal 140-A) and the pedestal 140-A (the lift pad is separated from the pedestal 140-A). The lift pad may be spaced apart from the base 140-A for the purpose of rotating the lift pad (and the wafer disposed thereon) relative to the base 140-A. The lift pad may also be spaced apart for the purpose of allowing access by an end effector for wafer delivery (e.g., placement or removal of a wafer from the lift pad).

In an embodiment, the lift pad and base configuration 1100 including the short-stroke pad lift mechanism 440-A is configured to support a lift pad substantially similar in size to a wafer (e.g., substantially similar in diameter to the lift pad and the wafer), such as the lift pad and base configurations shown in Figures 4, 5A-5C, and 9A-9C. In addition, according to an embodiment of the present disclosure, the lift pad and base configuration 1100 including the short-stroke pad lift mechanism 440-A is configured to support a lift pad smaller than a wafer (e.g., the diameter of the lift pad is smaller than the diameter of the wafer), such as the lift pad and base configurations shown in Figures 6, 7A-F, and 10A-10D. In some embodiments, the lifting pad and base configuration 1100 allows integration with a carrier ring assembly (not shown). In yet other embodiments, the lifting pad and base configuration 1100 can be implemented within a single workstation and/or a multi-workstation processing tool.

The base 140-A of the lift pad and base configuration 1100 can be controlled by the base control unit 450 of Figures 4 and 6, so that the movement of the base 140-A is achieved by the base and lift pad actuator 515 of Figure 5B and/or the base and lift pad actuator 515' of Figures 7B-7C. In particular, the central axis 510-A is interconnected to the base 140-A and to the base bracket 1101, so that the movement of the base bracket relative to the main frame 1105 is converted into the movement of the base 140-A. For example, the base control unit 450 controls the movement of the base bracket to induce the movement of the base 140-A (e.g., upward and downward along the central axis 471-A shown in Figure 14C) through the central axis 510-A during the pre-processing, processing, and post-processing sequences. In particular, the Z motor 445-A is configured to drive a ball screw (not shown) (e.g., ball screw 443 of FIG. 4 ) that is interconnected to a slider/carrier (not shown) via a ball screw nut such that rotation of the ball screw is converted into motion of the carrier parallel to the center axis 471-A (e.g., in the z-direction). The Z motor 445-A and ball screw (and other necessary accessories) remain fixed relative to the main frame 1105 such that motion of the carrier is relative to the main frame 1105. Additionally, the base bracket 1101 is interconnected to the carrier such that motion of the carrier is converted into motion of the base bracket 1101. The telescoping bladder 420-A facilitates motion of the base 140-A.

The lift pad of the lift pad and base configuration 1100 can be controlled by the lift pad control unit 455 of Figures 4 and 6, so that the movement of the lift pad is achieved by the base and lift pad actuator 515 of Figure 5B and/or the base and lift pad actuator 515' of Figures 7B-7C. In particular, the lift pad control unit 455 controls the movement of the lift pad shaft 560-A to induce the movement of the lift pad. In particular, the pad shaft 560-A extends from the lift pad along the center axis 471-A, as shown in Figure 14C. For example, the pad shaft 560-A is interconnected to the ferromagnetic seal assembly 425-A, which is interconnected to the base bracket via the short-stroke lift pad lifting mechanism 440-A. The pad lift mechanism 440-A is first introduced in FIG. 4 and further shown in FIG. 11A as a short-stroke coupling mechanism 440 configured to provide movement of the lift pad relative to the base 140-A. The ferromagnetic seal assembly 425-A is movably attached to the base bracket 1101 via the short-stroke lift pad lift mechanism 440-A. In this regard, movement of the base bracket 1101 is translated into movement of the base 140-A and the coupled lift pad, as previously described. In particular, movement of the base bracket 1101 without engaging the short-stroke lift pad lift mechanism 440-A provides movement of the base 140-A and the lift pad such that there is no gap between the lift pad and the base 140-A. When the lift pad raising mechanism 440-A is engaged, the lift pad moves additionally relative to the base 140-A to create the gap. The ferromagnetic seal assembly 425-A includes a short-stroke telescoping bladder configured to facilitate movement of the lift pad through the pad shaft. The ferromagnetic seal assembly 425-A is configured to provide a vacuum seal about the pad shaft when the pad shaft 560-A is rotating and when the pad shaft 560-A is not rotating.

In addition, the ferromagnetic seal assembly 425-A facilitates the rotation of the lift pad shaft 560-A contained in the vacuum environment. For example, the ferromagnetic seal assembly 425-A includes a rotation/theta motor 427-A in a belt-pulley configuration for the rotation of the lift pad shaft 560-A and the corresponding rotation of the lift pad relative to the base 140-A. The electric slip ring 1125 is configured to provide transmission of power and/or electrical signals through the lift pad shaft 560-A for rotation.

In addition, the lift pad and base configuration 1100 includes an upper bearing assembly 755-A (first introduced in FIG. 7D as high temperature bearing 755, and discussed more fully with respect to FIGS. 16-17), and a lower bearing assembly 1120. The upper bearing assembly 755-A and the lower bearing assembly 1120 are configured to be centered on the lift pad shaft 560-A within the central shaft 510-A.

FIG. 11B is a perspective view of the substrate processing system of FIG. 11A including a lift pad and base arrangement 1100, and further depicts elements of a short-stroke pad lift mechanism 440-A, according to one embodiment of the present disclosure. In particular, the pad lift mechanism 440-A includes an upper hard stop 1210 and a lower hard stop 1211, both of which are fixed relative to the main frame 1105. The carriage rollers 1221 and 1222 are fixed relative to the base bracket so that movement of a slide/plate (not shown) interconnected to a ball screw (not shown) in the Z direction is translated into corresponding movement of the carriage rollers 1221 and 1222 in the Z direction. The movement of the short-stroke pad lift mechanism 440-A is more fully described with respect to FIGS. 12-13.

When the short stroke pad lifting mechanism 440-A is not engaged, it is in a neutral position and is configured to provide simultaneous movement of the base 140-A and the lifting pad so that there is no gap between the lifting pad and the base 140-A. In the neutral position, the upper hard stop 1210 and the lower hard stop 1211 are not engaged (e.g., not engaged with the lever 1225), and the lever 1225 is loosely constrained between the bracket rollers 1221 and 1222.

On the other hand, when the lift pad raising mechanism 440-A is engaged, the lift pad performs additional movement relative to the base 140-A to create a gap between the lift pad and the base 140-A. In particular, the lever 1225 engages with the upper hard stop 1210 to induce movement of the lift pad relative to the base 140-A, thereby providing rotation of the lift pad relative to the base 140-A. In addition, the lever 1225 engages with the lower hard stop 1211 to induce movement of the lift pad relative to the base 140-A to allow entry of the end effector for wafer delivery. In addition, the pivoted yoke 1240 is configured to counteract and/or eliminate torque applied to the upper and lower bearings of the pad shaft 560-A due to actuation of the lift pad raising mechanism 440-A. More particularly, the lift pad raising mechanism 440-A is configured to repeatedly separate the lift pad relative to the base 140-A in a manner that maximizes the life of each component. For example, without any torque being counteracted or eliminated, the bearing assembly on the pad shaft 560-A (e.g., the high temperature bearing assembly 755-B) will fail prematurely. In this regard, the plurality of yoke assemblies implemented within the lift pad raising mechanism 440-A are configured to offset and/or eliminate the torque applied to the bearings of the pad shaft 560-A resulting from the raising of the lift pad to minimize wear.

FIG12A is a perspective view of a short-stroke pad lift mechanism 440-A of a substrate processing system including the pad and pedestal arrangement 1100 of FIG11A-11B according to one embodiment of the present disclosure. The pad and pedestal arrangement 1100 including the short-stroke pad lift mechanism 440-A is configured to support a pad having a size (e.g., diameter) substantially similar to that of a wafer, or a pad having a size (e.g., diameter) smaller than that of a wafer.

In one embodiment, the lift pad raising mechanism 440-A shown in FIG. 12A is configured to raise the lift pad for rotation relative to the base 140-A by engaging with the upper hard stop 1210, and to raise the lift pad relative to the base 140-A for entry by the end effector by engaging with the lower hard stop 1211. In other embodiments, the lift pad and base configuration 1100 can be modified to provide one of a plurality of lift pad raising actions provided by the short-stroke lift pad raising mechanism 440-A. For example, the lift pad raising mechanism 440-A can be modified to include only the upper hard stop 1210 configured for raising the lift pad for rotation relative to the base 140-A. In this case, a lift pin assembly may be configured within the lift pad and base configuration 1100 to allow entry of the end effector.

As shown in FIG. 12A , the lift pad and base arrangement 1100 is located within a main frame 1105, wherein the main frame 1105 is placed into (e.g., fixed within) a processing chamber. An upper hard stop 1210 and a lower hard stop 1211 are fixed relative to the main frame 1105. For example, the upper hard stop 1210 can be fixed directly to the main frame 1105, or fixed to the main frame 1105 through one or more intermediate elements. In particular, a main frame extension 1106 is attached to the main frame 1105, and both the upper hard stop 1210 and the lower hard stop 1211 are attached to the main frame extension 1106. In this manner, the upper hard stop 1210 and the lower hard stop 1211 do not move relative to the main frame 1105.

The lift pad and base arrangement 1100 includes a base bracket 1101 that is movably interconnected to a main frame 1105 via a slider/plate and ball screw/Z motor 445-A arrangement, as previously described. For example, the base bracket 1101 is attached to the center axis 510-A of the base 140-A (e.g., via a telescoping bladder 420-A) so that any movement of the base bracket 1101 caused by actuation of the ball screw/Z motor 445-A arrangement is converted into movement of the base 140-A. In addition, the slider 1235 is fixed relative to the base bracket 1101. In this way, the slider 1235 moves together with the base bracket 1101 in the same linear Z direction.

The base bracket extension 1231/1232 is fixed with respect to the base bracket 1101. For example, the base bracket extension 1231/1232 can be directly attached to the base bracket 1101. In addition, the bracket roller 1221 is attached to the base bracket extension 1231. Moreover, the bracket roller 1222 is attached to the base bracket extension 1232. In this way, the bracket roller 1221/1222 moves together with the base bracket 1101 in the same linear z direction.

The lift pad and base arrangement 1100 includes a lift pad bracket 1230 movably attached to a slider 1235. Because the slider 1235 is fixed relative to the base bracket 1101, any movement of the base bracket 1101 is translated into the same movement of the slider 1235 in the linear z-direction. In addition, because the lift pad bracket 1230 is movably attached to the slider 1235, the lift pad bracket 1230 can have additional movement relative to the base bracket 1101 (e.g., to create a spacing of the lift pad from the base 140-A). The interface between the base bracket 1101, the slider 1235, and the lift pad bracket 1230 will be described more fully with respect to FIG. 13.

The lift pad and base arrangement 1100 includes a yoke 1240 rotatably attached to a lift pad bracket 1230. When the short-stroke lift pad raising mechanism 440-A is engaged (e.g., the lever 1225 is engaged with the upper hard stop 1210 or the lower hard stop 1211), the yoke 1240 interfaces with the ferromagnetic seal assembly 425-A via rollers 1255/1256. The ferromagnetic seal assembly 425-A, first introduced in FIGS. 4 and 6, includes connector arms 1251/1252 that are disposed on opposite sides of the ferromagnetic seal assembly 425-A. Roller 1255 is attached to one end of connector arm 1251 and roller 1256 is attached to one end of connector arm 1252 such that rollers 1255/1256 are disposed on opposite sides of ferromagnetic seal assembly 425-A. When pad lift mechanism 440-A is actuated to separate the lift pad from base 140-A, yoke 1240 is configured to counteract and/or eliminate torque applied to pad shaft 560-A. The interface between the yoke and ferromagnetic seal assembly 425-A will be described more fully with respect to FIG. 13.

The lift pad and base arrangement 1100 includes a lever 1225 that is rotatably attached to the lift pad bracket 1230 via a pin 1226. In this regard, any movement of the pin 1226 will be translated into similar movement of the ferromagnetic seal assembly 425-A relative to the base 140-A and the base bracket 1101. For example, movement of the pin 1226 is induced by engagement between the lever 1225 and the upper hard stop 1210 or the lower hard stop 1211. Accordingly, any movement of the pin 1226 is translated into similar movement of the pad shaft 560-A and the attached lift pad relative to the base 140-A. The interfaces between the pin 1226, lever 1225, lift pad bracket 1230, ferromagnetic seal assembly 425-A, and pad shaft 560-A will be more fully described with respect to Figures 13 and 14A-14D.

FIG. 12B is a diagram depicting a motion sequence of the short-stroke pad lift mechanism 440-A of the lift pad and pedestal arrangement 1100 of FIGS. 11A-11B and 12A according to one embodiment of the present disclosure. In one embodiment, the short-stroke pad lift mechanism 440-A may be implemented in a lift pad and pedestal arrangement 1100 in which the diameter of the lift pad is smaller than the diameter of the wafer, so that the lift pad may be lifted to allow rotation of the lift pad relative to the pedestal 140-A and also to provide lifting of the lift pad to allow access to an end effector for wafer transfer. Moreover, in another embodiment, the short stroke pad lifting mechanism 440-A can be implemented in a lift pad and pedestal configuration 1100 where the diameter of the lift pad is approximately the same size as the wafer diameter, so that the lift pad can be raised to allow rotation of the lift pad relative to the pedestal 140-A. In this case, wafer transfer can be accomplished by a lift pin assembly.

The lift pad and base configuration 1100 is shown in state 1203 with the short-stroke lift pad elevation mechanism 440-A in a neutral state. The short-stroke pad elevation mechanism 440-A when not engaged is in a neutral position and is configured to provide simultaneous movement of the base 140-A and the lift pad, wherein the lift pad is placed on the base 140-A using a base referencing force (e.g., about 1 pound during processing and about 15 pounds when the chamber is at atmosphere) such that there is no gap between the lift pad and the base 140-A. For example, the base reference force is applied in part by the weight of the pad shaft 560-A, the ferromagnetic seal assembly 425-A, and the spring (e.g., by the force applied by its spring constant) so that when the pad lift mechanism 440-A is in a neutral state, the lift pad is constantly referenced to the base 140-A. Because the theta motor 427-A is offset from the pad shaft 560-A, the spring 1411 is used to compensate and/or eliminate any torque induced by the theta motor 427-A acting on the pad shaft 560-A.

More specifically, when the pad lift mechanism 440-A is in a neutral state, the lever 1225 rotationally attached to the pin 1226 is not engaged with the upper hard stop 1210 or the lower hard stop 1211, both of which are fixed relative to the main frame 1105. That is, the lever 1225 is loosely constrained between the bracket rollers 1221 and 1222, both of which are fixed relative to the base bracket 1101 and also move with the slider/carrier movably attached to the ball screw. In this regard, when the short-stroke pad lift mechanism 440-A is in the neutral position, the pin 1226 moves with the base bracket 1101, and any movement of the base bracket 1101 by the actuation of the Z motor 445-A and the ball screw is converted into simultaneous movement of the base 140-A and the lift pad. For example, when the base 140-A moves with the base bracket 1101 attached to the slider/carrier in response to the ball screw, the lift pad moves with the base 140-A because the lift pad is placed on the base.

On the other hand, when the lift pad raising mechanism 440-A is engaged, the lift pad performs additional movement relative to the base 140-A to create a gap between the lift pad and the base 140-A. In particular, states 1204 and 1205 of the lift pad and base configuration 1100 show the engagement of an upper hard stop 1210 (e.g., a roller) that separates the lift pad from the base 140-A to allow rotation of the lift pad. States 1201 and 1202 of the lift pad and base configuration 1100 show the engagement of a lower hard stop 1211 (e.g., a roller) that separates the lift pad from the base 140-A to allow entry of the end effector arm for wafer delivery.

In state 1204 of the lift pad and base configuration 1100, the short-stroke lift pad raising mechanism 440-A begins to engage the upper hard stop 1210. Specifically, the base bracket 1101 approaches its highest point of upward travel in the z-direction. As shown, as the lift pad and base configuration 1100 travels upward in the z-direction relative to the main frame 1105, the lift pad and base configuration 1100 approaches its highest position. That is, as the base 140-A and base bracket 1101 move upward (e.g., as the base 140-A approaches its highest position), the lever 1225 begins to engage the upper hard stop 1210. In this regard, the pad raising mechanism 440-A is about to or begins to leave the neutral state.

In state 1205, the lift pad and base arrangement 1100 is configured to raise the lift pad by upward movement of the base (e.g., about 1 mm) to create a gap between the lift pad and the base 140-A to allow rotation of the lift pad by actuation of the short-stroke pad lift mechanism 440-A. In particular, the short-stroke lift pad lift mechanism 440-A is fully engaged with the upper hard stop 1210. That is, the base 140-A and the base bracket 1101 continue to move upward until the base bracket 1101 reaches its highest position. In this case, the lever 1225 is fully engaged with the upper hard stop 1210, and the lever 1225 is fully rotated around the pin 1226. That is, upper hard stop 1210 applies a downward force to lever 1225 and bracket roller 1222 applies an upward force to lever 1225, causing lever 1225 to rotate (e.g., clockwise) about pin 1226. Because the lever is rotationally fixed to pin 1226 and the pin is movably attached to slider 1235 (fixed relative to base bracket 1101), the rotation of lever 1225 is converted into linear motion (z direction) of pin 1226 relative to base 140-A and base bracket 1101. Moreover, because the resulting force (from the interaction of the lever with the upper hard stop 1210 and the carriage roller 1222) is relatively close to the pin 1226, the linear motion of the pin 1226 is small (e.g., about 1 mm). In addition, the linear motion of the pin 1226 is converted into linear motion of the pad shaft 560-A through interaction with the yoke 1240 and the ferromagnetic seal assembly 425-A to create a gap between the lift pad and the base 140-A, as will be more fully described with respect to Figures 14A-14D.

In state 1201 of the lift pad and base configuration 1100, the short-stroke lift pad raising mechanism 440-A begins to engage the lower hard stop 1211. Specifically, the base bracket 1101 is nearing its lowest point of downward travel in the z-direction. As shown, as the lift pad and base configuration 1100 travels downward in the z-direction relative to the main frame 1105, the lift pad and base configuration 1100 approaches its lowest position. That is, as the base 140-A and base bracket 1101 move downward (e.g., as the base 140-A approaches its lowest position), the lever 1225 begins to engage the lower hard stop 1211. In this regard, the pad raising mechanism 440-A will or begins to leave the neutral state.

In state 1202, the lift pad and base arrangement 1100 is configured to raise the lift pad (e.g., about 14-18 mm) by downward movement of the base to create a gap between the lift pad and the base 140-A to facilitate entry of the end effector for wafer delivery by actuation of the short-stroke pad lift mechanism 440-A. In particular, the short-stroke lift pad lift mechanism 440-A is fully engaged with the lower hard stop 1211. That is, the base 140-A and the base bracket 1101 continue to move downward until the base bracket 1101 reaches its bottommost position. In this case, the lever 1225 is fully engaged with the lower hard stop 1211, and the lever 1225 is fully rotated around the pin 1226. That is, lower hard stop 1211 applies an upward force to lever 1225 and bracket roller 1221 applies a downward force to lever 1225 to cause lever 1225 to rotate (e.g., clockwise) about pin 1226. Because the lever is rotationally fixed to pin 1226 and the pin is movably attached to slider 1235 (fixed relative to base bracket 1101), the rotation of lever 1225 is converted into linear motion (z-direction) of pin 1226 relative to base 140-A and base bracket 1101. Because the resulting forces (from the interaction of the lever with the lower hard stop 1211 and the carriage roller 1221) are relatively far from the pin 1226, the linear motion of the pin 1226 is more significant (e.g., about 14-18 mm). In addition, the linear motion of the pin 1226 is converted into linear motion of the pad shaft 560-A by interaction with the yoke 1240 and the ferromagnetic seal assembly 425-A to create a gap between the lift pad and the base 140-A, as will be more fully described with respect to Figures 14A-14D.

FIG. 13 is a perspective view of the short-stroke lift pad raising mechanism 440-A of FIG. 12A according to an embodiment of the present disclosure, and more specifically shows the interface between the slider 1235 and the yoke 1240 that provides the lift pad with respect to the base 140-A. In particular, the slider 1235 is fixed with respect to the base bracket 1101. For example, the slider 1235 can be directly attached to the base bracket 1101, or attached to the base bracket 1101 through one or more intermediate elements (such as through a base bracket extension 1233 that can be directly attached to the base bracket 1101). In this regard, any linear movement of the base bracket 1101 (e.g., in the z-direction) is converted into a similar movement of the slider 1235 (e.g., in the z-direction).

In addition, the lift pad bracket 1230 is movably attached to the slider 1235. When the short-stroke lift pad raising mechanism 440-A is in its neutral state, the lift pad bracket 1230 moves with the slider 1235 so that no relative motion is experienced between the lift pad bracket 1230 and the base bracket 1101. In this regard, any linear motion of the base bracket 1101 (e.g., in the z-direction) is converted into a similar motion of the lift pad bracket 1230 (e.g., in the z-direction). On the other hand, when the pad raising mechanism 440-A is engaged with the upper hard stop 1210 or the lower hard stop 1211, the lift pad bracket moves upward relative to the base bracket 1101 by the action of the slider 1235. 13 depicts a yoke 1240 rotatably attached to a lift pad bracket 1230 via a pin 1227.

FIG. 14A is a perspective view of the lift pad raising mechanism 440-A of FIG. 12A according to one embodiment of the present disclosure, and more specifically shows the interface between the yoke 1240 and the ferromagnetic seal assembly 425-A that provides the lift pad with respect to the base. In particular, the yoke 1240 is rotatably attached to the lift pad bracket 1230 by the pin 1227. The yoke 1240 is configured to interface with the ferromagnetic seal assembly 425-A. In this regard, any linear movement of the pin 1226 is translated to the lift pad bracket 1230 as previously described, further translated to the yoke 1240 by the pin 1227, and further translated to the ferromagnetic seal assembly 425-A. In particular, any linear motion of the yoke 1240 is further converted into similar linear motion of the pad shaft 560-A and the lift pad by the ferromagnetic seal assembly 425-A.

FIG. 14B is a perspective view of a yoke 1240 interfacing with a ferromagnetic seal assembly 425-A according to one embodiment of the present disclosure. The yoke 1240 is rotatably attached to the lift pad bracket 1230 by a pin 1247. As shown, a yoke base 1245 is rotatably attached to the lift pad bracket 1230. A yoke arm 1246 extends from the yoke base 1245. In addition, a yoke extension 1241 and a yoke extension 1242 both extend from the yoke arm 1246. More specifically, FIG. 14B depicts the interface between the yoke extensions 1241/1242 and the connector arms 1251/1252 of the ferromagnetic seal assembly of the lift pad raising mechanism 440-A of FIG. 13A that provides movement of the lift pad relative to the base 140-A, according to one embodiment of the present disclosure. In particular, upward movement of the yoke 1240 engages the yoke extensions 1241/1242 with the rollers 1255/1256. That is, the yoke extension 1241 engages the roller 1255 attached to the ferromagnetic seal connector arm 1251, while the yoke extension 1242 engages the roller 1256 attached to the ferromagnetic seal connector arm 1252. Because the pin 1226 is fixed relative to the yoke 1240, and the yoke 1240 is fixed relative to the pad shaft 560-A via the ferromagnetic seal assembly 425-A when the pad lifting mechanism 440-A is engaged (for example, by engagement of the yoke extension 1241/1242 with the roller 1255/1256), when the pin 1226 undergoes linear motion in the z direction relative to the base 140-A and the base bracket 1101 (for example, when the lever 1225 engages with the upper hard stop 1210 or the lower hard stop 1211), this is converted into linear motion of the pad shaft 560-A in the z direction to create a gap between the lifting pad and the base 140-A.

In addition, the pivoting yoke 1240 is configured to offset and/or eliminate the torque applied to the upper and lower bearings of the pad shaft 560-A due to the actuation of the lift pad raising mechanism 440-A. In particular, the yoke 1240 pivots about the pin 1247 and is configured to balance the forces along the center axis 471-A of the stroke so that no torque or insignificant torque is applied to the upper and lower bearings of the pad shaft 560-A. That is, contact through the fork extension 1241/1242 of the yoke 1240 is achieved in a manner that offsets and/or eliminates the torque applied to the upper and lower bearings of the pad 560-A by utilizing equal forces on the rollers 1255/1256, which are fixed relative to the ferromagnetic seal assembly 425-A via their respective connector arms 1251/1252.

FIG. 14C provides a perspective view of a clamping mechanism for connecting elements of a ferromagnetic seal assembly 425-A to a pad shaft 560-A extending from a lift pad according to an embodiment of the present disclosure. In this regard, any linear motion of the ferromagnetic seal assembly 425-A (e.g., in the z-direction) is converted into a similar linear motion of the lift pad (e.g., in the z-direction). In particular, the bottom of the ferromagnetic seal assembly 425-A includes a disk 1440 and a clamp 1430 extending from the disk 1440. The clamp 1430 is clamped to the pad shaft 560-A such that any rotation of the disk 1440 is converted into a rotation of the pad shaft 560-A. For example, the rotation of the disk 1440 is achieved by the motion of the belt-pulley 1420, such as provided by the theta motor 427-A. FIG. 14D is a perspective view of the clamp 1430 of FIG. 14C , wherein the disk 1440 and the clamp 1430 are securely attached to the pad 560-A by a clamping mechanism provided by the clamp 1430, according to one embodiment of the present disclosure.

FIG. 15A is a perspective view of a substrate processing system including a lift pad and pedestal arrangement 1500, wherein a lift pin assembly (not shown) provides wafer delivery, according to one embodiment of the present disclosure. FIG. 15A depicts another short stroke pad lift mechanism 440-B, which provides elevation of the lift pad relative to the pedestal by upward movement of the pedestal to allow rotation of the lift pad, according to one embodiment of the present disclosure, wherein the lift pad may be substantially similar in size to or smaller than the wafer.

According to one embodiment of the present disclosure, the short stroke pad lift mechanism 440-B is configured to separate a lift pad (not shown) from a base 140-A. The lift pad and base arrangement 1500 is located within a main frame 1105, wherein the main frame 1105 is placed into (e.g., secured within) a processing chamber. Movement of the base 140-A is provided relative to the main frame, and movement of the lift pad is provided relative to both the main frame 1105 (e.g., the lift pad moves with the base bracket 1101) and the base 140-A (the lift pad is separated from the base 140-A). For the purpose of rotating the lift pad (and a wafer disposed thereon) relative to the base 140-A, the lift pad can be separated from the base 140-A.

The base 140-A of the lift pad and base configuration 1500 may be controlled by the base control 450 of Figures 4 and 6 such that movement of the base 140-A is achieved by the base and lift pad actuator 515 of Figure 5B and/or the base and lift pad actuator 515' of Figures 7B-7C. The lift pad of the lift pad and base configuration 1500 may be controlled by the lift pad control 455 of Figures 4 and 6 such that movement of the lift pad is achieved by the base and lift pad actuator 515 of Figure 5B and/or the base and lift pad actuator 515' of Figures 7B-7C.

FIG. 15B is a perspective view of the substrate processing system of FIG. 15A including a lift pad and base arrangement 1500, and depicts elements of a short-stroke pad lift mechanism 440-B, according to one embodiment of the present disclosure. In particular, the pad lift mechanism 440-B includes a base support roller 1521 fixed relative to the base bracket 1101. In addition, a lever 1525 is rotatably attached to the ferromagnetic seal assembly 425-A via a pin 1526, such as via a connector arm 1251/1252. The pad lift mechanism 440-B includes two levers 1525 on opposite sides of the ferromagnetic seal assembly 425-A that act together to lift the ferromagnetic seal assembly 425-A relative to the base bracket 1101.

FIG. 15C is a perspective view of the lift pad raising mechanism 440-B of FIG. 15A according to an embodiment of the present disclosure, and more specifically shows the interface between one of the levers 1525 and the ferromagnetic seal assembly 425-A that provides movement of the lift pad relative to the base 140-A. In particular, the pad raising mechanism 440-B includes a hard stop 1510 attached to the main frame 1105. When the base bracket 1101 moves upward relative to the main frame 1105, the lever 1525 also moves with the base bracket 1101 until it engages with the hard stop 1510. When the lever 1525 engages the hard stop 1510, the lever 1525 rotates about the pin 1526 and induces linear motion (e.g., in the z-direction) of the pin 1526 relative to the base bracket 1101. For example, the lever 1525 experiences forces due to the hard stop 1510 and the base support roller 1521. Because the pin 1526 is fixed relative to the ferromagnetic seal assembly 425-A, the linear motion of the pin 1526 is converted into similar linear motion of the ferromagnetic seal assembly 425-A and, accordingly, the pad 560-A. In this regard, when the pad lift mechanism 440-B engages the hard stop 1510, the lift pad is separated from the base 140-A for the purpose of rotation of the lift pad relative to the base 140-A.

FIG. 15D is a perspective view of the lift pad raising mechanism 440-B of FIG. 15A according to one embodiment of the present disclosure, and more specifically shows the interface between the yoke 1540 and the base bracket 1101 that provides the lift pad with respect to the base. As shown, the yoke 1540 is rotatably attached to the base bracket 1101. The yoke 1540 provides a balanced force to the ferromagnetic seal connector arms 1251/1252. That is, the yoke 1540 balances the force by its rotation to apply equal force on either side of the ferromagnetic seal assembly 425-A. In this regard, there is no torque or insignificant torque (eg, no effective radial force on the bearing) applied to the pad shaft 560-A by any actuation of the pad lift mechanism 440-B.

FIG. 16A is a diagram depicting the movement of the lift pad raising mechanism 440-B of FIG. 15A at a point in time just prior to separating the lift pad from the base, according to one embodiment of the present disclosure. As shown, in the lift pad and base configuration 1500, the short-stroke lift pad raising mechanism 440-B is beginning to engage with the hard stop 1510. Specifically, the base bracket 1101 is approaching its highest point of upward travel in the z-direction. As shown, the lift pad and base configuration 1500 is approaching its highest position as it travels upward in the z-direction relative to the main frame 1105. That is, as the base 140-A and base bracket 1101 move upward (e.g., the base 140-A is approaching its highest position), the lever 1525 begins to engage with the hard stop 1510. In this regard, the pad lift mechanism 440-B is about to or begins to leave the neutral state. At this point in time, the lift pad 630-A is placed on the base 140-A. For example, the MCA 595-A of the reference base is still in contact with the lift pad 630-A.

FIG. 16B is a diagram depicting the movement of the lift pad raising mechanism 440-B of FIG. 15A at a point in time after the lift pad 630-A is separated from the base 140-A according to an embodiment of the present disclosure. The lift pad and base arrangement 1500 is configured to raise the lift pad 630-A by upward movement of the base 140-A (e.g., approximately 1 mm) to create a gap between the lift pad 630-A and the base 140-A to allow rotation of the lift pad 630-A by actuation of the short-stroke pad raising mechanism 440-B. In particular, the short-stroke lift pad raising mechanism 440-B is fully engaged with the hard stop 1510. That is, the base 140-A and the base bracket 1101 continue to move upward until the base bracket 1101 reaches its highest position. In this case, the lever 1525 is fully engaged with the hard stop 1510, and the lever 1525 is fully rotated around the pin 1526. That is, the hard stop 1510 applies a downward force to the lever 1525, and the base support roller 1521 applies an upward force to the lever 1525, causing the lever 1525 to rotate around the pin 1526 (e.g., clockwise). Because the lever is rotationally fixed to pin 1526, and pin 1526 is movably attached to slider 1531 (fixed relative to base bracket 1101), rotation of lever 1525 is converted into linear motion (z direction) of pin 1526 relative to base 140-A and base bracket 1101. In addition, linear motion of pin 1526 is converted into linear motion of pad shaft 560-A through ferromagnetic seal assembly 425-A to create a gap between the lift pad and base 140-A.

FIG. 17A is a diagram of the lift pad and base arrangement 1100 of FIGS. 11-14 and a high temperature bearing assembly 755-A suitable for use in the lift pad and base arrangement 1500 of FIGS. 15-16 according to one embodiment of the present disclosure. The high temperature bearing assembly 755-A was first introduced with respect to FIG. 7D. Although FIG. 17A is described with respect to a small lift pad 630-A having a diameter less than the wafer diameter, the high temperature bearing assembly 755-A is implemented using a lift pad having a diameter substantially similar to the wafer diameter. In an embodiment, the high temperature bearing assembly 755-A is configured to operate in a high temperature environment, such as a chamber above 300 degrees Celsius.

The high temperature bearing assembly 755-A of FIG. 17A is similar in configuration to the high temperature bearing assembly 755-B of FIGS. 16A-16B and the high temperature bearing assembly 755 of FIG. 7D , except for the length of the inner sapphire bushing 1724. In particular, the length of the inner sapphire bushing 1724 of FIG. 17A is configured to accommodate the spacing between the lift pad and the base 140-A for the purpose of rotating the lift pad (and the wafer disposed thereon) relative to the base 140-A, and for the purpose of allowing end effector access for wafer delivery (e.g., placement or removal of wafers from the lift pad). The travel of the lift pad relative to the base 140-A is approximately 1 mm, and the travel of the lift pad for access to the end effector is approximately 14-18 mm. In this regard, the length L of the high temperature bearing assembly 755-A of FIG. 17A is configured to accommodate the longer travel of the lift pad for the end effector passage. On the other hand, the high temperature bearing assembly 755-B of FIGS. 16A-16B is configured to accommodate only the spacing between the lift pad and the base 140-A for the purpose of rotating the lift pad (and the wafer disposed thereon) relative to the base 140-A. For example, the lift pin assembly is provided for the end effector passage. In this regard, the length of the high temperature bearing assembly 755-B does not need to accommodate the longer travel of the lift pad for the end effector passage, and the length is much shorter than the length of the high temperature bearing assembly 755-A. The description provided for high temperature bearing assembly 755-A is applicable to each of the high temperature bearing assemblies described throughout this application.

In addition, the configuration of the previously described lifting pad raising mechanism 440-A does not generate torque or generates insignificant torque (e.g., radial force) on the high temperature bearing assembly 755-A (e.g., A-heat high temperature bearing assembly). Specifically, when the lifting pad raising mechanism 440-A raises the pad shaft 560-A to separate the lifting pad 630-A from the base 140-A, insignificant torque or no torque is applied to the high temperature bearing assembly 755-A.

As shown in FIG. 17A , the high temperature bearing assembly 755-A includes an outer stack on the inner wall of the center shaft 510-A of the base 140-A, and an inner stack on the outer diameter of the pad shaft 560-A.

In particular, the inner stack includes a retaining/snagging ring 1720, a load distribution washer 1721, a spring wave washer 1722, a load neutralizing and distribution washer 1723, and an inner sapphire bushing 1724. The inner sapphire bushing 1724 has a top edge surface 1791 and a bottom edge surface 1792, wherein both surfaces have conical, angled, or pushed surfaces. In one embodiment, FIG. 17D shows the inner sapphire bushing 1724 having the annular shape of the high temperature bearing assembly 755-A. In this regard, the inner sapphire bushing 1724 has a conical cross-section. In addition, the negative load centering and distribution gasket 1723 has a wedge-shaped, conical, angled, or pushed surface. The conical surface for the negative load centering and distribution gasket 1723 and the inner sapphire bushing 1724 helps to center the gasket 560-A within the central shaft 510-A.

In addition, the outer stack includes a retaining/snapping ring 1710, a load distribution washer 1711, a spring wave washer 1712, a load neutralizing and distribution washer 1713, and an outer sapphire bushing 1714. The outer sapphire bushing 1714 has a top edge surface 1781 and a bottom edge surface 1782, wherein both surfaces have conical, angled, or pushed surfaces. FIG. 17C shows the outer sapphire bushing 1714 having the annular shape of the high temperature bearing assembly 755-A according to an embodiment of the present disclosure. In this regard, the outer sapphire bushing 1714 has a conical cross-section. In addition, the negative load centering and distribution gasket 1713 has a wedge-shaped, conical, angled, or pushed surface. The conical surface for the negative load centering and distribution gasket 1713 and the outer sapphire bushing 1714 helps to center the pad shaft 560-A within the central shaft 510-A. The outer sapphire bushing 1714 is configured to contact (e.g., rub) the inner sapphire bushing 1724 when the lifting pad 630-A is separated from the base 140-A.

The lifting pad and base configuration shown in FIG17A includes centering chamfers 1751/1752 configured together to support high temperature bearing assemblies. For example, centering chamfer 1751 is located on the inner wall of center shaft 510-A and can provide a fixing capability to stack and hold the high temperature bearing assembly 755-A outside of center shaft 510-A. In addition, centering chamfer 1752 is located on the outer diameter of pad shaft 560-A and can provide a fixing capability to stack and hold the high temperature bearing assembly 755-A inside pad shaft 560-A.

The high temperature bearing assembly 755-A is configured to provide constant centering of the pad 560-A within the central shaft 510-A during operation of the pad 560-A (e.g., rotation, elevation, movement, etc.). In addition, the high temperature bearing assembly 755-A is configured to provide constant centering when exposed to varying temperatures. That is, the high temperature bearing assembly 755-A can accommodate different thermal expansion rates between the base 140-A and the pad 560-A and other components. For example, the sapphire composition of the inner sapphire bushing 1724 and the outer sapphire bushing 1714 within the high temperature bearing assembly 755-A allows for thermal mismatch between the washer 560-A and the base 140-A to provide constant centering of the washer 560-A within the central axis 510-A of the base 140-A. More specifically, due to thermal expansion, the inner and outer stacked metal elements provide a preload force that causes the corresponding tapered elements (e.g., washers and bushings) to remain centered.

FIG. 17B is a perspective view of the high temperature bearing assembly 775-A of FIG. 17A according to one embodiment of the present disclosure. In particular, the inner stack of the high temperature bearing assembly 755-A disposed on the outer diameter of the washer 560-A is shown. The inner stack includes a retaining/snapping ring 1720, a load distribution washer 1721, a spring wave washer 1722, a load neutralization and distribution washer 1723, and an inner sapphire bushing 1724. In addition, a chamfer 1752 is shown located on the inner sapphire bushing 1724.

In one embodiment, the wave washer 1722 in the inner stack has three contact points to promote the load distribution washer 1721 to evenly distribute the force throughout the collar 1720. In addition, the wave washer 1712 in the outer stack has three contact points to promote the load distribution washer 1711 to evenly distribute the force throughout the collar 1710.

FIG. 18 shows a control module 1800 for controlling the above-described system. In one embodiment, the control module 110 of FIG. 1 may include some example components of the control module 1800. For example, the control module 1800 may include a processor, a memory, and one or more interfaces. The control module 1800 may be used to control devices within the system based in part on sensed values. By way of example only, the control module 1800 may control one or more valves 1802, filter heaters 1804, pumps 1806, and other devices 1808 based on sensed values and other control parameters. By way of example only, the control module 1800 receives sensed values from a pressure gauge 1810, a flow meter 1812, a temperature sensor 1814, and/or other sensors 1816. The control module 1800 may also be used to control process conditions during the delivery and deposition of precursors to the film. The control module 1800 typically includes one or more memory devices and one or more processors.

The control module 1800 can control the activities of the precursor delivery system and the deposition equipment. The control module 1800 executes a computer program including a set of instructions for controlling the following: processing timing, temperature of the delivery system, and pressure differential across filters, valve positions, gas mixing, chamber pressure, chamber temperature, substrate temperature, RF power level, substrate chuck or base position, and other parameters of a particular process. The control module 1800 can also monitor the pressure differential and automatically switch the delivery of gaseous precursors from one or more paths to one or more other paths. Other computer programs stored in a memory device associated with the control module 1800 can be used in some embodiments.

There will usually be a user interface associated with the control module 1800. The user interface may include a display 1818 (e.g., a display screen and/or a graphics software display for displaying equipment and/or process conditions), and a user input device 1820 (e.g., a pointing device, a keyboard, a touch screen, a microphone, etc.).

Computer programs that control the delivery, deposition, and other steps of precursors in a processing sequence may be written in any conventional computer-readable programming language: assembly language, C, C++, Pascal, Fortran, or others. The compiled object code or script is executed by the processor to perform the tasks specified in the program.

The control module parameters are related to process conditions such as filter pressure differential, process gas composition and flow rate, temperature, pressure, plasma conditions (such as RF power level and low frequency RF frequency), cooling gas pressure, and chamber wall temperature.

System software can be designed or configured in many different ways. For example, subroutines or control objects for various chamber components can be written to control the operation of the chamber components necessary to perform the deposition processes of the present invention. Examples of programs or portions of programs for this purpose include substrate positioning code, process gas control code, pressure control code, heater control code, and plasma control code.

The substrate positioning program may include code for controlling chamber components for loading the substrate onto a pedestal or chuck and for controlling the distance between the substrate and other parts of the chamber, such as gas inlets and/or targets. The process gas control program may include code for controlling gas composition and flow rate, and optionally for flowing gas into the chamber to stabilize the pressure in the chamber prior to deposition. The filter monitoring program may include code for comparing measured pressure differentials to predetermined values and/or for switching paths. The pressure control program may include code for controlling the pressure in the chamber by adjusting, for example, a throttle valve in the chamber exhaust system. The heater control program may include code for controlling the flow of current to a heating unit for heating components within the precursor delivery system, a substrate and/or other parts of the system. Alternatively, the heater control program may control the delivery of a heat transfer gas such as helium to the substrate chuck.

Examples of sensors that may be monitored during deposition include, but are not limited to, mass flow control modules, pressure sensors (such as pressure gauge 1810), and thermocouples (such as temperature sensor 1814/607) located in the delivery system, base, or chuck. Appropriately programmed feedback and control algorithms may be used with data from these sensors to maintain desired process conditions. The above describes implementations of embodiments of the present disclosure in single or multi-chamber semiconductor processing tools.

In some embodiments, the controller is part of a system, which may be part of the examples above. Such systems may include semiconductor processing equipment, which includes a processing tool or multiple processing tools, a chamber or multiple chambers, a platform or multiple platforms for processing, and/or specific processing components (substrate base, gas flow system, etc.). These systems may be integrated with electronic equipment that is used to control the operation of these systems before, during, and after semiconductor wafer or substrate processing. The electronic equipment may be referred to as a "controller" and it can control many components or sub-parts of the system or multiple systems. Depending on the processing requirements and/or type of system, the controller can be programmed to control any of the processes disclosed herein, including: delivery of process gases, temperature settings (e.g., heating and/or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and operation settings, substrate transfer in and out of a tool and other transfer tools and/or a loading lock connected or interfaced with a particular system.

Broadly speaking, a controller may be defined as an electronic device having integrated circuits, logic, memory, and/or software that receives commands, issues commands, controls operations, enables cleaning operations, enables endpoint measurements, etc. The integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and/or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). The program instructions may be instructions communicated to the controller in the form of a number of individual settings (or program files) that define operating parameters for a semiconductor substrate or system to perform a particular process. In some embodiments, the operating parameters may be part of a recipe defined by a process engineer to perform one or more processing steps during die fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and/or wafers.

In some embodiments, the controller may be part of or coupled to a computer that is integrated with the system, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller may be in the "cloud" of all or part of a wafer fab host computer system that allows remote access to substrate processing. The computer may allow remote access to the system to monitor the current progress of a manufacturing operation, review the history of past manufacturing operations, review trends or performance metrics from multiple manufacturing operations, to change parameters of a current process, to set processing steps after the current operation, or to initiate a new process. In some examples, a remote computer (e.g., a server) may provide process recipes to the system via a network, which may include a local area network or the Internet.

The remote computer may include a user interface that allows the input or programming of parameters and/or settings, which are then transmitted from the remote computer to the system. In some examples, the controller receives instructions in the form of data that specifies parameters for various processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process to be performed and the type of tool to which the controller is configured to interface or control. Thus, as described above, the controller may be distributed, such as by including one or more distributed controllers that are networked together and work toward a common purpose (such as the process and control described herein). An example of a distributed controller used for these purposes would be one or more integrated circuits in the chamber that communicate with one or more integrated circuits located remotely (such as at the platform level or as part of a remote computer) to combine to control the process in the chamber.

Without limitation, example systems may include plasma etching chambers or modules, deposition chambers or modules, spin-clean chambers or modules, metal plating chambers or modules, cleaning chambers or modules, bevel etching chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, atomic layer deposition (ALD) chambers or modules, atomic layer etching (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and any other semiconductor processing system that may be associated or used in the fabrication and/or production of semiconductor wafers.

As described above, depending on the process step or multiple process steps to be performed by the tool, the controller may communicate with one or more of the following: other tool circuits or modules, other tool components, group tools, other tool interfaces, adjacent tools, adjacent tools, tools located throughout the factory, a host computer, another controller, or tools used for material transfer, which carry containers of wafers to and from tool locations and/or load ends within a semiconductor production factory.

The description of the above embodiments is provided for the purpose of illustration and description. It is not intended to be exhaustive or to limit the present disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but where appropriate, are interchangeable and can be used in the selected embodiment even if not specifically shown or described. The above elements or features can also be varied in many ways. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are intended to be included within the scope of the present disclosure.

Although the above embodiments have been described in some detail for the purpose of clarity of understanding, it will be apparent that several changes and modifications may be implemented within the scope of the appended claims. Therefore, the present embodiments are to be considered illustrative rather than restrictive, and the embodiments are not limited to the details provided herein, but may be modified within the scope of the claims and equivalents.

100: Reactor system/substrate processing system 101: Wafer 102: Chamber 102a: Upper chamber 102b: Lower chamber 104: Power supply 106: Matching network 108: Process input and control 110: Control module 112: Gas supply manifold 114: Process gas 120: Lift pin actuator ring 122: Lift pin control unit 140: Base 140’: Base 140’’: Base 140’’’: Base 140a’: Partial 140a’’: Partial 140b’: Partial 140b’’: Partial 140c’: Partial 140-A: Base 150: Shower head 180: Spider fork 200: Carrier Ring 220: Engagement and Rotation Mechanism 226: Spider Fork 300: Multi-Station Processing Tool 302: Inbound Loader Locking Unit 304: Outbound Loader Locking Unit 306: Robot 308: Wafer Transfer Box 310: Atmosphere Port 316: Chamber Transfer Port 318: Substrate Support 400: Lift Pad and Base Configuration 415: Lift Pin Assembly 420: Telescopic Capsule 420’: Telescopic Capsule 420-A: Telescopic Capsule 425: Ferromagnetic Seal 425’: Ferromagnetic Seal 425-A: Ferromagnetic Seal Assembly 427: Rotary Motor 427-A: Rotary/θ Motor 430: Lifting pad 435: Compliant shaft/flexible coupler 437: Ball screw 440: Short-stroke coupling mechanism 440-A: Pad lifting mechanism/short-stroke coupling mechanism 440-B: Pad lifting mechanism 443: Ball screw 445: Z motor 445’: Z motor 445-A: Z motor 450: Base control unit 455: Lifting pad control unit 470: Heating element 470’; Heating element 471: Center axis 471’: Center axis 471-A: Center axis 480: Cooling element 500B: Assembly 509: Outer edge 510’: Center axis 510’’: Center axis 510-A: Center axis 515: Actuator 515’: Actuator 518: Base axis 518’: Base axis 519: Pad 533: Top surface 543: Bottom surface 550: Lift pin actuator 550’: Lift pin actuator 555: Lift pin support 555’: Lift pin support 557: Lift pin 557’: Lift pin 560: Pad 560’: Pad 560-A: Pad 570: ESC/ESC assembly 575: Pad top surface 577: Pad diameter 590: Wafer 595: Pad support 595-A: MCA 600: Lift pad and base configuration 600’: Lift pad and base configuration 603: Slide 605: Flange 607: Thermocouple 630: Lift pad 630-A: Lift pad 631: Top surface 632: Bottom surface 700B: Assembly 700C: Assembly 705: Recess 706: Recess bottom surface 710: Edge 720: Top surface 740: Sapphire ball/MCA 745: Sapphire ball/MCA 755: High temperature bearing 755-A: Bearing assembly 755-B: High temperature bearing assembly 760: Wafer support 775: Lift pad top surface 777: Pad diameter 800: Flowchart 805: Operation 810: Operation 820: Operation 825: Operation 830: Operation 840: Operation 845: Operation 850: Operation 855: Operation 860: Operation 901: Line 902: Line 903: Line 904: Line 940: Rotational displacement 950: Coordinate system 969: Displacement 1040: Rotational displacement 1050: Coordinate system 1100: Lift pad and base configuration 1101: Base bracket 1105: Main frame 1106: Main frame extension 1120: Lower bearing assembly 1125: Electric slip ring 1201: Status 1202: Status 1203: Status 1204: Status 1205: Status 1210: Upper hard stop 1211: Lower hard stop 1221: Bracket roller 1222: Bracket roller 1225: Lever 1226: Pin 1227: Pin 1230: Lifting pad bracket 1231: Base bracket extension 1232: Base bracket extension 1233: Base bracket extension 1235: Slider 1240: Yaw 1241: yoke extension/fork extension 1242: yoke extension/fork extension 1245: yoke base 1246: yoke arm 1247: pin 1251: connector arm 1252: connector arm 1255: roller 1256: roller 1411: spring 1420: belt-pulley 1430: clamp 1440: plate 1500: lift pad and base configuration 1510: hard stop 1521: base support roller 1525: lever 1526: pin 1531: slide 1540: yoke 1710: Retaining/Securing Ring 1711: Load Distribution Gasket 1712: Corrugated Gasket 1713: Load Neutralizing Gasket 1714: External Sapphire Bushing 1720: Retaining/Securing Ring 1721: Load Distribution Gasket 1722: Corrugated Gasket 1723: Load Neutralizing Gasket 1724: Internal Sapphire Bushing 1751: Chamfer 1752: Chamfer 1781: Top Edge Surface 1782: Bottom Edge Surface 1791: Top Edge Surface 1792: Bottom Edge Surface 1800: Control Module 1802: Valve 1804: Filter heater 1806: Pump 1808: Other devices 1810: Pressure gauge 1812: Flow meter 1814: Temperature sensor 1816: Other sensors 1818: Display 1820: Input device

The embodiments may be best understood by reference to the following description taken in conjunction with the accompanying drawings.

FIG. 1 illustrates a substrate processing system for processing wafers, for example, to form films thereon.

FIG. 2 illustrates a top view of a multi-workstation processing tool in which four processing workstations are provided, according to one embodiment.

3 is a schematic diagram showing an embodiment of a multi-workstation processing tool having an inbound load lock and an outbound load lock according to one embodiment.

FIG. 4 depicts a substrate processing system including a lift pad and pedestal arrangement according to one embodiment of the present disclosure, wherein the lift pad is sized to substantially match the wafer.

FIG. 5A is a cross-sectional view of the substrate processing system of FIG. 4 according to one embodiment of the present disclosure.

5B is a cross-sectional view of the substrate processing system of FIG. 4 showing a lift pad and pedestal configuration, wherein the lift pad is sized to approximately match the wafer, and wherein the pedestal and lift pad are at a height that allows lift pins to be extended for wafer transfer purposes, according to one embodiment of the present disclosure.

5C is a diagram of an interface between a lift pad and a base including a pad gap setting minimum contact area (MCA) according to one embodiment of the present disclosure.

FIG. 6 depicts a substrate processing system including a lift pad and pedestal arrangement according to one embodiment of the present disclosure, wherein the lift pad is smaller than the wafer.

7A is a perspective view of the substrate processing system of FIG. 6 including a lift pad and pedestal arrangement according to one embodiment of the present disclosure, wherein the lift pad is smaller than the wafer.

7B is a cross-sectional view of the substrate processing system of FIG. 6 including a lift pad and pedestal arrangement according to one embodiment of the present disclosure, wherein the lift pad is smaller than the wafer.

7C is a cross-sectional view of the substrate processing system of FIG. 6 including a lift pad and base configuration including a lift pin assembly, wherein the lift pad is smaller than the wafer, according to one embodiment of the present disclosure.

7D is a cross-sectional view of a lift pad to pedestal interface in the substrate processing system of FIG. 6 including a lift pad and pedestal arrangement wherein the lift pad is smaller than the wafer according to an embodiment of the present disclosure.

7E is a perspective view of a top surface of a lift pad in the substrate processing system of FIG. 6 including a lift pad and base arrangement according to one embodiment of the present disclosure.

7F is a perspective view of a bottom surface of a lift pad in the substrate processing system of FIG. 6 including a lift pad and base arrangement according to one embodiment of the present disclosure.

FIG. 8 is a flow chart depicting a method for operating a processing chamber configured for depositing a film on a wafer, wherein the method provides for rotating the wafer during processing in the processing chamber without rotating the pedestal, which advantageously filters out both chamber and pedestal asymmetries, according to an embodiment of the present disclosure.

9A and 9B are diagrams depicting a motion sequence of a lift pad and pedestal configuration according to an embodiment of the present disclosure, wherein the lift pad is sized to approximately match the wafer and includes rotation of the wafer during processing within the processing chamber without rotation of the pedestal, which advantageously filters out both chamber and pedestal asymmetries.

9C depicts a diagram of the orientation of a lift pad relative to a pedestal in a lift pad and pedestal configuration during a first processing sequence, a rotation sequence, and a second processing sequence, wherein the lift pad is approximately the same size as the wafer, according to an embodiment of the present disclosure.

10A and 10B are diagrams illustrating a motion sequence of a lift pad and pedestal configuration according to an embodiment of the present disclosure, wherein the lift pad is smaller than the wafer, wherein the lift pad is configured to allow transfer of the wafer (e.g., by an end effector arm) and include rotation of the wafer during processing within a processing chamber without rotation of the pedestal, which advantageously filters out both chamber and pedestal asymmetries.

FIG. 10C is a diagram illustrating the motion sequence of a lift pad and pedestal configuration including a lift pin assembly according to an embodiment of the present disclosure, wherein the lift pad is smaller than the wafer and includes rotation of the wafer during processing within the processing chamber without rotation of the pedestal, which advantageously filters out both chamber and pedestal asymmetries.

10D is a diagram illustrating an orientation of a lift pad relative to a pedestal in a lift pad and pedestal configuration wherein the lift pad is smaller than the wafer during a first processing sequence, a rotation sequence, and a second processing sequence according to an embodiment of the present disclosure.

11A is a perspective view of a substrate processing system including a lift pad and pedestal configuration and depicting a short-stroke lift pad elevation mechanism according to an embodiment of the present disclosure, wherein the lift pad may be substantially similar in size to or smaller than a wafer.

11B is a perspective view of the substrate processing system of FIG. 11A including a lift pad and base configuration and depicting elements of a short-stroke lift pad elevation mechanism according to one embodiment of the present disclosure.

12A is a perspective view of a lift pad raising mechanism of a substrate processing system including the lift pad and base arrangement of FIGS. 11A-11B according to one embodiment of the present disclosure.

FIG. 12B is a diagram illustrating the movement sequence of the short-stroke pad lifting mechanism of the lift pad and base configuration of FIGS. 11A-11B and 12A according to an embodiment of the present disclosure, and depicts the lifting of the lift pad by the upward movement of the base to allow rotation of the lift pad, and the lifting of the lift pad by the downward movement of the base to facilitate entry of the end effector for wafer delivery.

13 is a perspective view of the lift pad raising mechanism of FIG. 12A and more specifically shows the interface between the slider and the yoke that provides movement of the lift pad relative to the base, according to one embodiment of the present disclosure.

14A is a perspective view of the lift pad elevation mechanism of FIG. 12A and more specifically shows the interface between the yoke and the ferromagnetic seal assembly that provides movement of the lift pad relative to the base, according to one embodiment of the present disclosure.

14B is a perspective view of the yoke of FIG. 14A interfaced with a ferromagnetic seal assembly according to one embodiment of the present disclosure.

FIG. 14C provides a perspective view of a clamping mechanism for connecting a ferromagnetic seal assembly to a pad shaft of a lift pad, such that movement of the ferromagnetic seal assembly is converted into movement of the lift pad, according to one embodiment of the present disclosure.

FIG. 14D is a perspective view of the clamp in the clamping mechanism of FIG. 14C according to an embodiment of the present disclosure.

FIG. 15A is a perspective view of a substrate processing system including a lift pad and pedestal configuration in which a lift pin assembly provides wafer delivery, and depicts another short-stroke pad lift mechanism that provides lift pad elevation relative to the pedestal by upward movement of the pedestal to allow rotation of the lift pad, wherein the lift pad may be substantially similar in size to or smaller than the wafer, according to one embodiment of the present disclosure.

15B is a perspective view of the substrate processing system of FIG. 15A including a lift pad and pedestal configuration and depicting elements of a short-stroke pad lift mechanism according to one embodiment of the present disclosure.

15C is a perspective view of the lift pad raising mechanism of FIG. 15A and more specifically shows the interface between the lever and the ferromagnetic seal assembly that provides movement of the lift pad relative to the base, according to one embodiment of the present disclosure.

15D is a perspective view of the lift pad raising mechanism of FIG. 15A and more specifically shows the interface between the yoke and the base bracket that provides movement of the lift pad relative to the base, according to one embodiment of the present disclosure.

FIG. 16A is a diagram illustrating the motion of the lift pad raising mechanism of FIG. 15A at a point in time just prior to separation of the lift pad from the base, according to an embodiment of the present disclosure.

FIG. 16B is a diagram illustrating the movement of the lift pad raising mechanism of FIG. 15A at a point in time after the lift pad is separated from the base according to an embodiment of the present disclosure.

FIG. 17A depicts a high temperature bearing assembly of a lift pad and base configuration according to one embodiment of the present disclosure.

FIG. 17B is a perspective view of the high temperature bearing assembly of FIG. 17A according to one embodiment of the present disclosure.

FIG. 17C shows an outer sapphire bushing having a ring shape of a high temperature bearing assembly according to one embodiment of the present disclosure.

FIG. 17D shows an inner sapphire bushing having a ring shape of a high temperature bearing assembly according to one embodiment of the present disclosure.

FIG18 shows a control module for controlling the above system.

425-A: Ferromagnetic seal assembly

440-A: Pad lifting mechanism/short stroke coupling mechanism

1101: Base bracket

1105: Main frame

1106: Main frame extension

1210: Upper hard stop

1211: Lower hard stop

1221: Bracket Roller

1222: Bracket Roller

1225: Leverage

1226: Sales

1230: Lifting pad bracket

1231: Base bracket extension

1232: Base bracket extension

1235: Sliding parts

1240: yoke

1251: Connector arm

1252: Connector arm

1255: Roller

1256: Roller

Claims (20)

A lifting pad elevating mechanism for use in a processing chamber, the lifting pad elevating mechanism comprising: a lifting pad for being movably mounted to a base of a main frame; a main frame extension fixedly coupled to the main frame; a lower hard stop fixedly coupled to the main frame extension; a base bracket movably coupled to the main frame, the base bracket fixedly interconnected to the base, wherein movement of the base bracket is converted into movement of the base; a first base bracket extension fixedly coupled to the base bracket and comprising a first bracket roller; a second base bracket extension fixedly coupled to the base bracket and comprising a second bracket roller; a sliding member fixedly coupled to the base bracket; a lift pad bracket movably coupled to the slider, the lift pad bracket interconnected to the lift pad; a lever rotatably connected to a pin of the lift pad bracket, wherein the lever is loosely constrained between the first bracket roller and the second bracket roller when the lever is not engaged with the lower hard stop in a neutral position; wherein when the base bracket moves downward toward a bottommost downward position, the lever is configured to rotate about the pin when engaged with the lower hard stop and the first bracket roller and separate the lift pad from a base top surface of the base. A lifting pad lifting mechanism for a processing chamber as claimed in claim 1, wherein the lifting pad is placed in a recess of the base so that a lifting pad surface is coplanar with a top surface of the base. As claimed in claim 1, a lifting pad lifting mechanism for a processing chamber, wherein when the lever rotates around the pin of the lifting pad bracket, the lifting pad bracket moves upward relative to the base bracket via the sliding member, so that the lifting pad moves upward relative to the base. A lift pad lifting mechanism for use in a processing chamber as claimed in claim 1, wherein the displacement of the lift pad away from the top surface of the base is sufficient for entry of an end effector. A lift pad lifting mechanism for a processing chamber as claimed in claim 1, further comprising: wherein when the base bracket moves upward toward the uppermost upward position, the lever is configured to rotate about the pin when engaging with an upper hard stop and the second bracket roller, and separate the lift pad from the top surface of the base by a process rotational displacement. A lift pad elevating mechanism for use in a processing chamber as claimed in claim 5, wherein the lift pad is configured to rotate relative to a top surface of the base when separated from the base between at least a first angular orientation and a second angular orientation. The lifting pad lifting mechanism for use in a processing chamber as claimed in claim 1 further comprises: A pad shaft extending from the lifting pad, wherein the lifting pad bracket is interconnected with the pad shaft. A lift pad raising mechanism for use in a processing chamber as claimed in claim 7, further comprising: A yoke movably interconnected to the second base bracket extension and movably interconnected to the lift pad via the pad shaft, wherein the yoke eliminates torque induced in the pad shaft when the lever engages an upper hard stop. A lift pad raising mechanism for use in a processing chamber as claimed in claim 1, wherein the first bracket roller is laterally offset from the second bracket roller relative to the base bracket, and wherein the first bracket roller is vertically offset from the second bracket roller relative to the base bracket. A lift pad raising mechanism for use in a processing chamber as claimed in claim 1, wherein when the lever is not engaged with an upper hard stop or the lower hard stop, movement of the base bracket is converted into movement of the lift pad and the base. An assembly for a processing chamber, comprising: a base assembly, comprising a base movably mounted to a main frame; a lift pad, configured to be placed near a base top surface of the base and move with the base assembly; a lift pad raising mechanism, configured to separate the lift pad from the base, the lift pad raising mechanism comprising: a main frame extension, fixedly coupled to the main frame; a lower hard stop, fixedly coupled to the main frame extension; a base bracket, movably coupled to the main frame, the base bracket fixedly interconnected to the base, wherein movement of the base bracket is converted into movement of the base; a first base bracket extension, fixedly coupled to the base bracket and comprising a first bracket roller; a second base bracket extension, fixedly coupled to the base bracket and comprising a second bracket roller; a slide interconnected to the base bracket; a lift pad bracket movably coupled to the slide, the lift pad bracket interconnected to the lift pad; a lever rotatably connected to a pin of the lift pad bracket, wherein the lever is loosely constrained between the first bracket roller and the second bracket roller when the lever is not engaged with the lower hard stop in a neutral position; wherein when the base bracket moves downward toward a bottommost downward position, the lever is configured to rotate about the pin when engaged with the lower hard stop and the first bracket roller and separate the lift pad from a base top surface of the base. An assembly for a processing chamber as claimed in claim 11, wherein the lift pad is placed in a recess of the base so that a lift pad surface is coplanar with a top surface of the base. As claimed in claim 11, an assembly for a processing chamber, wherein when the lever rotates around the pin of the lifting pad bracket, the lifting pad bracket moves upward relative to the base bracket via the sliding member, so that the lifting pad moves upward relative to the base. An assembly for a processing chamber as claimed in claim 11, wherein the displacement of the lift pad away from the top surface of the base is sufficient to allow entry of an end effector. As claimed in claim 11, the assembly for a processing chamber further comprises: wherein when the base bracket moves upward toward the uppermost upward position, the lever is configured to rotate about the pin when engaging with an upper hard stop and the second bracket roller and separate the lifting pad from the top surface of the base by a process rotational displacement. An assembly for a processing chamber as claimed in claim 15, wherein the lift pad is configured to rotate relative to a top surface of the base when separated from the base between at least a first angular orientation and a second angular orientation. The assembly for a processing chamber as claimed in claim 11 further comprises: A pad shaft extending from the lifting pad, wherein the lifting pad bracket is interconnected with the pad shaft. An assembly for a processing chamber as claimed in claim 17, further comprising: a yoke movably interconnected to the second base bracket extension and movably interconnected to the lift pad via the pad shaft, wherein the yoke eliminates torque induced in the pad shaft when the lever engages an upper hard stop. An assembly for a processing chamber as claimed in claim 11, wherein the first support roller is laterally offset from the second support roller relative to the base support, and wherein the first support roller is vertically offset from the second support roller relative to the base support. An assembly for a processing chamber as claimed in claim 11, wherein when the lever is not engaged with an upper hard stop or the lower hard stop, movement of the base bracket is converted into movement of the lift pad and base.

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