System and method for automatic correction of substrate misalignment

Abstract

FIELD OF THE INVENTION [0002] Embodiments described herein relate to semiconductor manufacturing and processing. More particularly, a processing system for automatically correcting misalignment of a substrate within a process chamber is provided. The processing system includes a process chamber having a substrate support disposed within a chamber volume of the process chamber. The substrate support includes a pocket for receiving the substrate and a plurality of flow conduits extending between an upper surface of the pocket and a lower surface of the substrate support. An imaging device is connected to the process chamber and configured to monitor the position of the substrate within the pocket of the substrate support.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE Embodiments of the present disclosure relate generally to semiconductor manufacturing and processing. More particularly, the present disclosure relates to a system and method for automatically correcting misalignment of a substrate within a process chamber. [Background technology]

[0002] In semiconductor device manufacturing processes such as CVD, epitaxy, or other thermal processes, substrates are often processed in a chamber or other processing equipment. To process a substrate in a chamber, the substrate may be rigidly secured to a substrate support within the chamber to reduce substrate movement. If the substrate moves during processing, it may become misaligned. Factors that can cause substrate misalignment include gas flow, pressure, and temperature around the substrate support during processing. If the substrate is misaligned, film thickness uniformity and / or film properties may be adversely affected.

[0003] In some semiconductor device manufacturing processing systems, substrates can be transferred between multiple chambers, each of which has a substrate support structure, such as a deposition tool, an etching tool, and an inspection tool. Substrates can be transferred between chambers by a transfer arm with a fork or end effector. This handling of substrate exchange can result in misalignment of the substrate relative to the substrate support, resulting in misalignment. When substrate support structures within a processing system are improperly aligned, the support structures do not hold the substrate at approximately the same tilt or are tilted. Therefore, when one support structure transfers a substrate to another, such as when lift pins remove the substrate from the blade of a transfer chamber substrate handler or place the substrate on a substrate support within a process chamber, one point on the substrate will likely contact the receiving support structure before other points. If substantial movement occurs before the remaining points make contact, the substrate may be in motion. Potentially contaminating particles can be scraped off the contact points of the substrate, causing contamination on the backside of the substrate. These particles can eventually migrate to the top of the substrate and deposit on the processed surface of the substrate, thereby contaminating microcircuits or other structures built on that surface. Furthermore, when not all points of the substrate contact the receiving support structure in close alignment, the substrate may be misaligned from its proper or expected position, resulting in an off-center substrate. Furthermore, temperature differences between the substrate and the substrate support can cause thermal shock, which can lead to substrate warping. Substrate warping can also lead to substrate misalignment. As discussed above, an off-center substrate may be subjected to uneven or otherwise improper processing, may come into contact with surfaces or objects within the processing system, contaminating the substrate, generating potentially contaminating airborne particles, or even damaging the substrate.

[0004] The need for placement accuracy is illustrated in FIG. 1. A typical substrate 10 and a substrate support, e.g., a susceptor 12, for holding the substrate 10 within a single-substrate process chamber are shown. For a given substrate 10, the diameter of the pocket that accommodates the substrate 10 on the substrate-receiving surface of the susceptor 12 is typically only slightly larger than the diameter of the substrate 10. A small gap 14 often exists between the edge of the substrate 10 and the edge of the pocket in the susceptor 12. The substrate 10 is centered within the pocket, maintaining a gap between the edge of the substrate 10 and the sidewalls of the pocket. If the substrate 10 contacts the sidewalls of the pocket, localized temperature variations occur, resulting in temperature gradients across the substrate 10. This can lead to nonuniform process results because most semiconductor processes are temperature-critical. Similarly, misaligned or off-center substrates can be damaged during placement in several different handling situations.

[0005] Substrate misalignment can occur before or during processing of a substrate in a process chamber. As discussed above, substrate misalignment can cause non-uniformity in process results. Therefore, when substrate misalignment is detected, such misalignment should be promptly corrected to prevent non-uniform or otherwise improper processing of the substrate.

[0006] Therefore, a need exists for a system and method for monitoring the position of a substrate and automatically correcting the position of the substrate when misalignment of the substrate is detected. Summary of the Invention

[0007] FIELD OF THE DISCLOSURE Embodiments of the present disclosure relate generally to semiconductor manufacturing and processing. More particularly, embodiments disclosed herein relate to systems and methods for automatically correcting misalignment of a substrate within a process chamber.

[0008] In some embodiments, a processing system for automatically centering a substrate within a process chamber is provided. The processing system includes a process chamber having a substrate support disposed within a chamber volume of the process chamber. The substrate support includes a pocket for receiving the substrate and a plurality of flow conduits extending between an upper surface of the pocket and a lower surface of the substrate support. An imaging device is connected to the process chamber and configured to monitor the position of the substrate within the pocket of the substrate support.

[0009] In some embodiments, a processing system for automatically centering a substrate within a process chamber is provided. The processing system includes a process chamber having a susceptor and a preheat ring disposed within a chamber volume of the process chamber. The susceptor includes a pocket for receiving the substrate, and the preheat ring radially overlaps the susceptor. A plurality of conduits extend through portions of the susceptor. An imaging device is connected to the process chamber and configured to monitor the substrate within the pocket of the susceptor.

[0010] In some embodiments, a method for automatically centering a substrate within a process chamber is provided. The method includes detecting a misalignment of a substrate loaded on a substrate support disposed within a chamber volume of the process chamber. The method includes determining a recommended adjustment to correct the misalignment based on the misalignment, and providing a flow of gas from the chamber volume to the substrate support based on the recommended adjustment. The method includes detecting a corrected position of the substrate on the substrate support, the corrected position corresponding to a center position of the substrate support. The method includes stopping the flow of gas to the substrate support to set the substrate to the corrected position on the substrate support.

[0011] So that the above-mentioned features of the present disclosure may be understood in detail, a more particular description of the present disclosure briefly summarized above will be had by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings depict only exemplary embodiments and therefore should not be considered as limiting the scope of the present disclosure, as other equally effective embodiments may also be permitted. [Brief explanation of the drawings]

[0012] [Figure 1] 1A-1C are schematic diagrams illustrating a 200 mm substrate in place in a pocket of a substrate holder of a susceptor in both a top view and a cross-sectional view, according to certain embodiments of the present disclosure. [Figure 2] 1 illustrates a schematic diagram of an exemplary processing system that can be used to perform the processing methods described herein, according to certain embodiments of the present disclosure. [Figure 3] 2B is a flow diagram illustrating an exemplary method for detecting substrate misalignment in the processing system of FIG. 2A, according to certain embodiments of the present invention. [Figure 4] 2B is a cross-sectional view of an exemplary susceptor that may be used in the processing system of FIG. 2A, according to certain embodiments of the present disclosure. [Figure 5] 3 is a flow diagram illustrating an exemplary method for automatically correcting misalignment of a substrate on the susceptor of FIG. 2, according to certain embodiments of the present disclosure. [Figure 6A] 3 is a cross-sectional view of an exemplary susceptor that may be used in the processing system of FIG. 2, in accordance with certain embodiments of the present disclosure. [Figure 6B] 3 is a cross-sectional view of an exemplary susceptor that may be used in the processing system of FIG. 2, in accordance with certain embodiments of the present disclosure. [Figure 7] 7 is a flow diagram illustrating an exemplary method for automatically correcting misalignment of a substrate on the susceptor of FIG. 6, according to certain embodiments of the present disclosure. [Figure 8A-B] 2B is a schematic diagram illustrating an exemplary susceptor that may be used in the processing system of FIG. 2A, according to certain embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further description.

[0014] The present disclosure relates generally to semiconductor manufacturing and processing, and more particularly to a system and method for automatically correcting misalignment of a substrate on a substrate support (e.g., a susceptor).

[0015] Processing systems for processing substrates are commonly known. Typically, such processing systems have a central transfer chamber mounted on an integrated platform. The transfer chamber is the center of action for moving substrates to be processed within the system. One or more process chambers are attached to the transfer chamber at slit valves through which substrates are passed by a substrate handler or robot. Access to the transfer chamber from the clean ambient environment is typically through one or more load lock chambers attached to other slit valves. The load lock chambers can open to a very clean room called a white area or to an optional substrate handling chamber, commonly called a mini-environment.

[0016] 2 is a schematic cross-sectional view of a processing system 100 that may be used to perform the processes described herein, where processing system 100 is configured to automatically correct the positioning of a substrate 108 on a substrate support, such as a susceptor 106, in a process chamber 101 when misalignment of the substrate 108 on the susceptor 106 is detected. The processing chamber 101 may be used for processing one or more substrates 108, including depositing material on an upper surface of the substrate 108 (which may be similar to substrate 10, for example).

[0017] The process chamber 101 may include, among other components, an array of radiant heat lamps 102 for heating the backside 104 of a susceptor 106 (which may be, for example, the susceptor 12 shown in FIG. 1 ) disposed within a chamber volume 123 of the process chamber 101. In some embodiments, the array of radiant heat lamps may be disposed on an upper dome 128. The susceptor 106 may be a disk-shaped susceptor 106 as shown, or may be a ring-shaped susceptor (not including a central opening) that supports the substrate from its edge to facilitate exposure of the substrate to the thermal radiation of the lamps 102.

[0018] The susceptor 106 is located within the process chamber 101 between an upper dome 128 and a lower dome 114. The upper dome 128, the lower dome 114, and a base ring 136 disposed between the upper dome 128 and the lower dome 114 generally define the interior region of the process chamber 101. A substrate 108 (not to scale) can be brought into the process chamber 101 and placed on the susceptor 106 via a loading port 103.

[0019] The susceptor 106 is shown in an elevated processing position, but can be moved vertically by an actuator (not shown) below the processing position to a loading position where the lift pins 105, passing through holes in the susceptor 106 and the central shaft 132, contact the lower dome 114 and lift the substrate 108 off the susceptor 106. A robot (not shown) can then enter the process chamber 101, engage the substrate 108, and remove it therefrom via the loading port 103. The susceptor 106 can then be moved upward to the processing position, and the substrate 108 can be placed on the front side 110 of the susceptor 106 with the device side 116 facing up.

[0020] While in the processing position, the susceptor 106 divides the interior space 123 of the process chamber 101 into a process gas region 156 above the substrate and a purge gas region 158 below the susceptor 106. To minimize the effects of spatial biases in heat and process gas flow within the process chamber 101, the susceptor 106 is rotated by a central shaft 132 during processing, thereby promoting uniform processing of the substrate 108. The susceptor 106 is supported by the central shaft 132 and moves the substrate 108 in an up-down direction 134 during loading and unloading of the substrate 108, and in some instances, during processing of the substrate 108. The susceptor 106 may be formed from silicon carbide or silicon carbide-coated graphite to absorb radiant energy from the lamps 102 and transfer the radiant energy to the substrate 108.

[0021] Typically, the central window portion of upper dome 128 and the bottom of lower dome 114 are formed of an optically transparent material, such as quartz. As used herein, "optically transparent" generally means that radiation passes through, but not necessarily 100%. As described in more detail below with respect to FIG. 2A, the thickness and curvature of upper dome 128 can be configured in accordance with the present invention to provide a flatter profile for uniform flow within the process chamber.

[0022] One or more lamps, such as an array of lamps 102, may be arranged around the central shaft 132 in a particular optimum desired configuration adjacent to and beneath the lower dome 114 to separately control the temperature of various regions of the substrate 108 while process gases are passing through, thereby promoting the deposition of material onto the upper surface of the substrate 108. Although not described in detail herein, the deposited material may include gallium arsenide, gallium nitride, or aluminum gallium nitride.

[0023] The lamps 102 may include bulbs 141 and may be configured to heat the substrate 108 to temperatures ranging from approximately 200 degrees Celsius to approximately 1600 degrees Celsius. Each lamp 102 is connected to a power distribution board (not shown), through which power is supplied to each lamp 102. The lamps 102 are disposed within lamp heads 145, which may be cooled during or after processing, for example, by cooling fluid introduced into channels 149 located between the lamps 102. Due in part to the lamp heads' close proximity to the lower dome 114, the lamp heads 145 cool the lower dome 114 conductively and radiatively. The lamp heads 145 may also further cool the lamp walls and the walls of a reflector (not shown) surrounding the lamps. Alternatively, the lower dome 114 may be cooled by a convective approach. Depending on the application, the lamp heads 145 may or may not contact the lower dome 114.

[0024] A circular shield 167 may optionally be positioned around the susceptor 106 and surrounded by the liner assembly 163. The shield 167 provides a preheat zone for the process gases while preventing or minimizing the leakage of thermal / light noise from the lamps 102 to the device side 116 of the substrate 108. The shield 167 may be made from CVD SiC, SiC-coated sintered graphite, grown SiC, opaque quartz, coated quartz, or any similar suitable material that is resistant to chemical decomposition by the process and purging gases.

[0025] The liner assembly 163 is sized to nest within or be surrounded by the inner periphery of the base ring 136. The liner assembly 163 protects the chamber volume 123 (i.e., the process gas region 156 and the purge gas region 158) from the metal walls of the process chamber 101, which can react with precursors and cause contamination within the processing volume 123. Although the liner assembly 163 is shown as a single unit, the liner assembly 163 may include one or more liners of various configurations.

[0026] The backside heating of the substrate 108 from the susceptor 106 results in the use of an optical pyrometer 118 for temperature measurement / control at the susceptor. This temperature measurement by the optical pyrometer 118 can also be performed on the device side 116 of a substrate with unknown emissivity, because heating the substrate front side 110 in this manner is emissivity independent. As a result, the optical pyrometer 118 can only sense radiation from the hot substrate 108 that is conducted from the susceptor 106, where background radiation reaching the optical pyrometer 118 directly from the lamps 102 is minimal.

[0027] Optionally, a reflector 122 may be positioned on the outside of the upper dome 128 to reflect infrared radiation emitted from the substrate 108 back toward the substrate 108. The reflector 122 may be secured to the upper dome 128 using a retaining ring 130. The reflector 122 may be made of a metal such as aluminum or stainless steel. Reflection efficiency may be improved by coating the reflector area with a highly reflective coating such as gold. The reflector 122 may have one or more conduits 126 connected to a cooling source (not shown). The conduits 126 connect to passages (not shown) formed on one side of the reflector 122. The passages are configured to carry a flow of fluid, such as water, and may extend horizontally along one side of the reflector 122 in any desired pattern covering a portion or the entire surface of the reflector 122 to cool the reflector 122.

[0028] Process gas supplied from a process gas source 172 is introduced into the process gas region 156 through a process gas inlet 174 formed in the sidewall of the base ring 136. The process gas inlet 174 is configured to direct the process gas in a generally radially inward direction. During a film formation process, the susceptor 106 can be positioned in a processing position proximate to and at approximately the same height as the process gas inlet 174, allowing the process gas to flow along flow paths 173 across, over, and around the upper surface of the substrate 108 in a laminar flow pattern. The process gas exits the process gas region 156 (along flow conduit 175) through a gas outlet 178 located on the opposite side of the process chamber 101 from the process gas inlet 174. Removal of the process gas through the gas outlet 178 can be facilitated by a vacuum pump 180 coupled to the gas outlet 178. Because the process gas inlet 174 and gas outlet 178 are aligned with one another and located at approximately the same height, it is believed that this parallel arrangement, when combined with the flatter upper dome 128, allows for a generally planar and uniform gas flow across the substrate 108. Rotation of the substrate 108 via the susceptor 106 can provide further radial uniformity.

[0029] Purge gas supplied from a purge gas source 162 is introduced into the purge gas region 150 through a purge gas inlet 164 formed in the sidewall of the base ring 136. The purge gas inlet 164 may be located at an elevation below the susceptor 106, allowing the purge gas to flow along a flow path 165 across, under, and over the bottom surface of the susceptor 106. The purge gas may be an inert gas such as hydrogen or nitrogen. The flow of purge gas within the purge gas region 158 helps prevent or reduce the flow or diffusion of process gas from the process region 156 above the susceptor 106 to the purge gas region 158 below the susceptor 106. The purge gas exits the purge gas region 158 through a gas outlet 179. Alternatively, purge gas region 158 may further include a vent (not shown) for exhausting purge gas from purge gas region 158 directly into gas outlet 178. Removal of purge gas via gas outlet 179 may also be facilitated by vacuum pump 180.

[0030] As described above, the substrate 108 may become misaligned on the substrate receiving surface of the susceptor 106 (e.g., due to deterioration or other factors), and / or the susceptor 106 may become misaligned and not rotated evenly, tilted, or off-center. Such misalignment may result in uneven processing of the substrate 108. A position sensing device, such as a camera 200, may be utilized within the processing system 100 and connected to the process chamber 101 to detect such misalignment for automatic correction by the processing system 100.

[0031] 2, the process chamber 101 may include a camera 200 for monitoring the position of the substrate 108 and for detecting misalignment and subsequent correction of the substrate 108 on the susceptor 106. The camera 200 may be communicatively connected to a controller 202 that controls the operation of the camera 200 (e.g., on / off, focusing, imaging, etc.). In some embodiments, the controller 202 is communicatively connected to a central processing unit (CPU) 204. The controller 202 may download a program stored in a storage medium via an input / output (I / O) device (not shown) and control the camera 200 in accordance with the program to execute a position detection method, which will be described below.

[0032] In one embodiment, as shown in FIG. 1 , the camera 200 can be positioned above the top of the process chamber 101, and a collection device for the camera, such as a light pipe, can extend through the top of the process chamber 101 and be positioned within the process gas region 156. Alternatively, the camera 200 can be positioned inside the process chamber 101. For example, the camera 200 can be positioned within the opening 186 in the upper dome 128 between the upper dome 128 and the reflector 122. The camera 200, or a collection device for the camera, can be positioned through an inlet connecting the conduit 126 to the process chamber 101, or alternatively, the camera 200 can be connected to the chamber using a housing. The camera 200 can be capable of operating at vacuum or atmospheric pressure. The camera 200 can be present in the process chamber 101 to capture images of the substrate 108, edge ring, mask, and / or susceptor 106. The position of the camera 200 relative to the upper dome 128 and the susceptor 106, as well as the optical properties of the camera 200, can be determined to ensure a field of view of the substrate 108 that includes the edge ring, the mask, and / or the edge of the susceptor 106 for use in position detection.

[0033] Camera 200 is merely one example of a device that can be used for imaging; any other type of imaging device can be used as a position detection device. In embodiments, more than one camera can be used to capture images of substrate 108, edge ring, mask, and / or susceptor 106. In embodiments, camera 200 is an imaging device and can be a high-efficiency, low-voltage complementary metal oxide semiconductor (CMOS) sensor that functions as a single-chip video camera. The CMOS sensor can be a VGA type. Camera 200 can include a lens, such as a wide-angle lens or a plano-convex lens, with an appropriate focal length to provide sufficient visual clarity within the desired operating range of camera 200. Those skilled in the art will recognize that various lenses (e.g., telephoto lenses or rotating prism lenses) can be used for various applications. Furthermore, it will be appreciated that other types of cameras or optical sensors can be used, including, but not limited to, SVGA, XGA, MEGA pixel type cameras, or other imaging devices. If desired, multiple imaging devices with different resolutions can be used, along with lenses of various types and focal lengths. The camera or sensor may be of the static (still) or dynamic (video) type, and may be of the charged coupled device (CCD) type. In addition, the camera may be used to output a video signal in any standard TV format.

[0034] 3 is a flow diagram illustrating an exemplary process 300 for detecting misalignment of an object in a processing system, according to certain embodiments of the present disclosure. At 302, an image of the object may be acquired. The object may be a substrate, a mask, an edge, a susceptor, or the like. The image may be acquired using a high-resolution video camera (e.g., CMOS, SVGA, XGTA, or MEGA pixel type). According to certain embodiments, the image may be acquired while the object is rotating.

[0035] At 304, values (e.g., RGB values) associated with pixels in at least one region of the image may be determined. The values may be from the raw image or a filtered image.

[0036] At 306, object misalignment may be detected based on the values. According to certain embodiments, detecting object misalignment may include blocks 306A and 306B. For example, at 306A, at least one of a centroid value of pixels in the region or an average weight of pixels in the region may be calculated, and at 307B, object misalignment may be detected based on the calculated centroid value or average weight of pixels in the region.

[0037] According to certain embodiments, process 300 may further include acquiring a second image of the object subsequent to (e.g., at a later time) acquiring the first image. Values associated with pixels in at least one region of the second image may be determined and compared to the determined values associated with pixels in at least one region of the first image. Detection of object misalignment may further be based on the comparison (e.g., by monitoring how centroid values and / or average weights of pixels in the at least one region change from the first image to the second image).

[0038] According to certain embodiments, the detected misalignment value can be output to enable correction of the misalignment. In one embodiment, the detected misalignment can be output to a feedback system for use in determining a recommended adjustment to the substrate to correct the misalignment. The feedback system can then initiate a process of moving the position of the substrate on the susceptor to correct the misalignment based on the determined recommended adjustment. In some embodiments, the determined recommended adjustment can shift the position of the substrate within the susceptor pocket by between about 0.1 mm and about 0.5 mm. Additionally or alternatively, the misalignment value can be stored in a memory connected to the optical imaging device. The center of gravity and weight values can be output as a signal and monitored for vibrations that may be indicative of misalignment, such as when output on a screen, monitor, or printed.

[0039] Additional information regarding systems and methods for detecting substrate misalignment can be found, for example, in US Pat. No. 9,959,610.

[0040] Once misalignment of the substrate 108 on the susceptor 106 is detected, the misalignment of the substrate 108 can be corrected, thereby preventing errors in the manufacturing or processing of the substrate.

[0041] 4 is a cross-sectional view of an exemplary susceptor 400 that may be used in the process chamber 101 of FIG. 1, in accordance with certain embodiments of the present disclosure. As described above, a substrate 108 may be brought into the chamber volume 123 of the process chamber 101 and placed in a pocket 404 on a substrate receiving surface 403 of the susceptor 400 for processing of the substrate 108.

[0042] 4, a susceptor 400 includes a plurality of flow conduits 402 disposed within the susceptor 106, the plurality of flow conduits 402 being in fluid communication with a purge gas region 158 below the susceptor 106. The plurality of flow conduits 402 described herein can direct a flow of gas from the purge gas region 158 toward a pocket 404 portion of the susceptor 400 and any substrates 108 disposed within the pocket. The flow of gas through the flow conduits 402 at any substrate 108 disposed within the pocket 404 can be configured such that the pressure from the gas is sufficient to lift and move the substrate 108. The plurality of flow conduits 402 can be communicatively connected to and controlled by a feedback system described herein.

[0043] A feedback system can be connected between the plurality of flow conduits 402 in the susceptor 400, the controller 202, and the camera 200, such that the plurality of flow conduits 402 operate in response to misalignment of the substrate position detected by the camera 200 and correction of the substrate position. As described above, the camera 200 can be used by the feedback system to actively monitor the position of the substrate 108 in the pocket 404 to detect misalignment of the substrate 108 on the susceptor 106 and to determine when the misalignment has been corrected after a procedure to move the substrate has been initiated. When misalignment of the substrate 108 on the susceptor 106 is detected, the feedback system can then initiate an automatic correction procedure that provides a flow of gas through the plurality of conduits 402 to move the substrate 108 and correct the misalignment. The feedback system can also use the controller 202 to control each of the flow valves 412 to start and stop the flow of gas through the plurality of flow conduits 402 to control the flow of gas into the pocket 404.

[0044] In certain embodiments, each of the plurality of flow conduits 402 includes an inlet opening 408 in a bottom surface 413 of the susceptor 400, which is in fluid communication with an outlet opening 410 in a top surface 414 of a pocket 404 of the susceptor 400. In one embodiment, the outlet openings 410 may be located near the outer edge of the pocket 404 so that gas flow through the flow conduits 402 is directed toward the bottom edge 111 and bottom surface 109 of the substrate 108 within the pocket 404. The outlet openings 410 may also be formed along an inner sidewall of the pocket 404, which may direct gas flow from each outlet opening 410 toward a side of the substrate 108. Alternatively, the outlet openings 410 may be located in any other portion of the pocket 404 to enable gas flow to be directed from the top surface 414 to any portion of the substrate 108. In other embodiments, the size of the outlet openings 410 in each of the plurality of flow conduits 402 may be approximately the same. Alternatively, the size of the outlet opening 410 can be varied to provide greater gas flow to particular portions of the pocket 404 .

[0045] In another embodiment, each of the plurality of flow conduits 402 may further include a controllable flow valve 412 for controlling the respective flow rate of gas through the respective plurality of flow conduits 402. In one embodiment, each of the flow valves 412 of the plurality of flow conduits 402 may be communicatively coupled to the controller 202 and the camera 200 in a feedback system. The feedback system may also be coupled to the CPU 204 for misalignment detection and correction detection by the camera 200. The CPU 204 may also be communicatively coupled to the susceptor 400 and may determine recommended adjustments when a misalignment is detected. The CPU 204 may provide instructions to the controller 202 to control the flow valves 412 of the plurality of flow conduits 402 to start and stop the flow of gas through the flow conduits 402 based on the recommended adjustments.

[0046] A plurality of flow valves 412 in the susceptor 400 are communicatively coupled to the controller 202, which can dynamically control the operation (e.g., opening and closing) of the flow valves 412 in a feedback system. When movement of the substrate 108 is desired (e.g., to correct a detected misalignment), the flow valves 412 are opened to allow gas from the purge gas region 158 below the susceptor 106 to enter and pass through the flow conduits 402 to a pocket 404 on the substrate receiving surface 403 of the susceptor 400. When the flow valves 412 are open, gas flowing through the plurality of flow conduits 402 described herein can be used to lift the substrate 108 from the surface 403 of the pocket 404 and move the substrate 108 along the horizontal XY plane of the pocket 404 using the pressure of the gas flowing from the flow conduits 402. In one embodiment, the flow valves 412 may be controlled to selectively flow gas through particular flow conduits 402 based on the desired direction of movement of the substrate 108. When an automatic correction procedure is initiated by the feedback system to move the substrate 108 to correct misalignment of the substrate 108, multiple flow valves 412 opened by the feedback system may be actuated together, separately, and / or sequentially in response to movement of the substrate 108 to correct the detected misalignment and center the substrate 108 within the pocket 404. In other embodiments, the flow valves 412 may be configured to be fixed flow valves that can be controlled by the feedback system to dynamically adjust and set the pressure of the gas flowing through the flow conduits 402 to control the amount of force applied to the substrate 108.

[0047] In certain embodiments, the control of the flow valves 412 is connected to a feedback system to move the substrate 108 when misalignment of the substrate 108 is detected. The feedback system can be connected between the camera 200, which monitors the position of the substrate 108, and the plurality of flow valves 412, such that the flow valves 412 selectively operate to correct the detected misalignment in response to the misalignment of the substrate 108 detected by the camera 200. As described herein, the camera 200 is used by the feedback system to detect misalignment of the substrate 108 within the pocket 404 of the susceptor 106. Based on the misalignment of the substrate 108 detected by the camera 200, the feedback system determines recommended adjustments to properly center the substrate 108 within the pocket 404. The feedback system then selectively controls the flow valves 412 to provide gas flow through specific flow conduits 402 based on the recommended adjustments, allowing and directing gas to specific portions of the substrate 108 to move the substrate 108 along the horizontal XY plane of the pocket 404.

[0048] For example, if the recommended adjustment includes moving the substrate 108 to the right of its current position, the feedback system can open the flow valves 412 of the multiple flow conduits 402 near the left side of the opposite substrate 108 to apply gas flow to the left side of the substrate 108 and push the substrate 108 to the right.

[0049] 5 is a flow diagram illustrating exemplary steps of a method 500 for automatically correcting misalignment of a substrate 108 by the processing system 100 when the substrate 108 is placed on the susceptor 400 of FIG. 4, according to certain embodiments of the present disclosure. The method 500 begins at 502 by detecting misalignment of the substrate 108 from the center position of the pocket 404 of the susceptor 400 in the processing system 100.

[0050] At 504, if a misalignment of the substrate 108 is detected, the processing system 100 determines a recommended adjustment to correct the detected misalignment and move the substrate 108 to a center position of the pocket 404. The recommended adjustment may be determined based on a first position of the substrate 108 from which the misalignment was detected by the camera 200.

[0051] At 506, the processing system 100 supplies a flow of gas to the pocket 404 of the susceptor 400 based on the recommended adjustment to move the substrate 108 along the horizontal XY plane of the pocket 404. In one embodiment, the gas is supplied by flowing through the plurality of flow conduits 402 of the susceptor 400 based on the recommended adjustment to lift the substrate 108 from its current misaligned position and move it to its expected center position. In one embodiment, if the detection of misalignment at step 502 and the supply of gas at step 506 occur during processing of the substrate 108, gas may already be flowing in the purge gas region 158 of the chamber volume 123 near the inlet openings 408 of the plurality of flow conduits 402, such that opening the flow valve 412 may be all that is necessary to flow gas through the plurality of flow conduits 402. Alternatively, if the detection of misalignment in step 502 and the supply of gas in step 506 are performed before processing begins, the supply of gas flow to pocket 404 in step 506 may further include initiating gas flow from purge gas source 162 into purge gas region 158 of chamber space 123.

[0052] In step 508, while gas is being supplied through the plurality of flow conduits 402 based on the recommended adjustment, the position of the substrate 108 within the pocket 404 is continuously monitored by the camera 200 and re-evaluated to determine whether the misalignment has been corrected so that the substrate 108 is in a centered position in the pocket 404. If the substrate remains off-center in the pocket 404 such that the current flow of gas supplied through the plurality of flow conduits 402 in step 506 no longer matches the recommended adjustment based on the second offset position of the substrate 108, steps 504 and 506 are repeated, where a new recommended adjustment is determined based on the second offset position of the substrate 108, and the gas flow is modified and supplied in step 506 based on the new recommended adjustment for the second offset position of the substrate 108.

[0053] If, in step 508, it is determined that the misalignment of the substrate 108 has been corrected, thereby moving the substrate 108 to a new position corresponding to the center position of the pocket 404, then, in step 510, the processing system 100 stops the flow of gas through the flow conduit 402 to set the substrate 108 to the new position of the pocket 404 corresponding to the center position.

[0054] 6A-6B are schematic cross-sectional views of a portion of an exemplary susceptor in a processing system 600, according to certain embodiments of the present disclosure.

[0055] The process chamber 600 includes a susceptor 602 having a pocket 603 for receiving a substrate 108 therein, and a preheat ring 604. Heating of the susceptor 602 and the preheat ring 604 contributes to the thermal decomposition of process gases on the substrate 108 disposed in the pocket 603 of the susceptor 602 to form one or more layers on the substrate 108. The preheat ring 604 may be coupled to a liner assembly 163 of the process chamber 600 for supporting and positioning the preheat ring 604. The preheat ring 604 extends radially inward from the liner assembly 163. The preheat ring 604 is configured to be positioned around the outer edge of the susceptor 602 when the susceptor 602 is in a processing position such as that shown in FIG.

[0056] The susceptor 602 has a raised boundary 605 that radially outwardly surrounds the pocket 603 of the susceptor 602. The raised boundary 605 has an upper surface 607 that faces the process gas volume 156 of the process chamber 101. The susceptor 602 has a radially outwardly extending outer flange 614 that is configured to overlap a corresponding overlapping portion of the preheat ring 604, as described in more detail below. The outer flange 614 extends radially outward relative to the raised boundary 605. An upper surface 622 of the outer flange 614 is recessed below the upper surface 607 of the raised boundary 605.

[0057] The preheat ring 604 includes a body 606 (e.g., annular) having an upper surface 608 that is flush with an upper surface 610 of the susceptor 602. The body 606 of the preheat ring 604 has a radially inwardly extending inner flange 612 that is configured to overlap an outer flange 614 of the susceptor 602. A lower surface 616 of the inner flange 612 is recessed above (from below) a lower surface 618 of the body 606. The inner flange 612 of the preheat ring 604 is positioned above the outer flange 614 of the susceptor 602, allowing the susceptor 602 to be lowered relative to the preheat ring 604 for substrate loading and unloading. As shown in Figures 6A and 6B, the inner flange 612 of the preheat ring 604 and the outer flange 614 of the susceptor 602 are spaced apart (e.g., do not touch each other). Figure 6A shows the susceptor 602 raised to the processing position. Figure 6B shows the susceptor 602 lowered to the loading position.

[0058] In certain embodiments, the susceptor 602 may further include a plurality of flow conduits 609 extending through the raised boundary 605. Each of the plurality of flow conduits 609 may include an inlet opening 611 in a side 619 of the raised boundary 605, the inlet opening 611 being in fluid communication with an outlet opening 613 in an inner surface 615 of the raised boundary 605 that leads to the pocket 603. In one embodiment, the outlet opening 613 of the flow conduit 609 may be positioned near a top surface 617 of the pocket 603 such that gas passing through the outlet opening 613 is directed toward the bottom edge 111 of the substrate 108. The plurality of flow conduits 609 described herein may direct gas flow from the purge gas region 158 toward the portion of the substrate 108 disposed within the pocket 603 such that the flow of gas from the flow conduit 609 is sufficient to move the substrate 108 within the pocket 603. The flow of gas through the plurality of flow conduits 402 can be controlled using a feedback system communicatively connected to the susceptor 602 and the camera 200. As described above, the camera 200 monitors the position of the substrate 108 within the pocket 603 and provides feedback as to when misalignment of the substrate 108 on the susceptor 106 is detected and corrected.

[0059] When movement of the substrate 108 within the pocket 603 is desired (e.g., to correct a detected misalignment), a feedback system initiates an automatic correction procedure according to the methods described herein to move the substrate 108. To move the substrate 108, the susceptor 602 is lowered to a predetermined centering position (shown in FIG. 6B ), which allows gas from the purge gas region 158 to flow through the flow conduits 609 toward the substrate 108 within the pocket 603. In one embodiment, when the susceptor 602 is lowered to the predetermined centering position, the susceptor 602 may be lowered approximately 5 mm relative to the preheat ring 604. As the susceptor 602 is lowered, gas from the purge gas region 158 may flow into the plurality of flow conduits 609 through a vertical gap 620 between an upper surface 622 of the outer flange 614 of the susceptor 602 and a lower surface 616 of the inner flange 612 of the preheat ring 604. Gas flow through the flow conduits 609 described herein can lift and move the substrate 108 along the top surface 617 of the pocket 603 and can enable movement of the substrate 108 along the horizontal XY plane of the pocket 603. When the feedback system determines that the substrate 108 is centered in the pocket 603, the susceptor 602 is raised to the processing position (shown in FIG. 6A ) so that the top surface of the susceptor 602 is flush with the top surface of the preheat ring 604. As the susceptor 602 moves to the processing position, the vertical gap 620 between the top surface 622 of the outer flange 614 of the susceptor 602 decreases, redirecting gas flow from the purge gas region 158 upward along the side 619 of the raised boundary 605 toward the process gas region 156. In the processing position, the vertical gap 620 between the upper surface 622 of the outer flange 614 of the susceptor 602 and the lower surface 616 of the inner flange 612 of the preheat ring 604 is about 1 mm or less, for example, about 0.5 mm to about 1 mm, for example, about 0.6 mm to about 0.8 mm, for example, about 0.6 mm.

[0060] 7 is a flow diagram illustrating an exemplary method 700 for automatically correcting misalignment of a substrate 108 when the substrate 108 is placed on the exemplary susceptor of FIG. 6, according to certain embodiments of the present disclosure. The method 700 begins at 702 with detecting misalignment of the substrate 108 from a center position of a pocket 603 of a susceptor 602 in a processing system 100 at a first position of the substrate 108.

[0061] At 704, if a misalignment of the substrate 108 is detected, the processing system 100 determines a recommended adjustment to correct the detected misalignment and move the substrate 108 to a center position of the pocket 603. The recommended adjustment may be determined based on a first position of the substrate 108 from which the misalignment was detected by the camera 200.

[0062] At 706, the processing system 100 provides a gas flow to the susceptor 602 based on the recommended adjustments to move the substrate 108 along the horizontal XY plane of the pocket 404. In one embodiment, to move the substrate 108 based on the recommended adjustments, the gas is provided by lowering the susceptor 602 and substrate 108 relative to the preheat ring 604 so that the gas flows through a number of flow conduits 609 in the susceptor 602.

[0063] In step 708, while gas is being supplied to the susceptor 602 to move the substrate 108, the position of the substrate 108 within the pocket 603 is continuously reevaluated by the camera 200, and the flow of gas through the flow conduits 609 corrects the misalignment to determine whether the substrate 108 has moved to a central position in the pocket 603. If the substrate remains off-center in the pocket 603 such that the current flow of gas through the plurality of flow conduits 609 supplied in step 706 no longer matches the recommended adjustment based on the second off-center position of the substrate 108 detected by the camera 200, steps 704 and 706 are repeated, where a new recommended adjustment is determined based on the second off-center position of the substrate 108, and the gas flow through the plurality of flow conduits 609 is changed based on the new recommended adjustment for the second off-center position of the substrate 108 and supplied in step 706.

[0064] If, in step 708, it is determined that the misalignment of the substrate 108 has been corrected, thereby moving the substrate 108 to a new position corresponding to the center position of the pocket 603, then, in 710, the flow of gas to the susceptor 602 is stopped so that the substrate 108 can be placed in its new position within the pocket 603 corresponding to the center position. In one embodiment, the flow of gas to the pocket 603 of the susceptor 602 can be stopped by raising the susceptor 602. In one embodiment, the susceptor 602 is raised to the processing position and the gas flow to the flow conduit 609 is redirected and thereby stopped. Once the gas flow has been stopped in step 710, the substrate 108 can be placed in its new position within the pocket 603.

[0065] 8A and 8B show schematic top views of an exemplary susceptor 800 that may be used in the processing system of FIG. 2A, according to certain embodiments of the present disclosure.

[0066] 8A , the susceptor 800 may include a plurality of flow conduits, in which a plurality of outlet openings 804 are arranged in a spiral pattern on the top surface 806 of the pocket 803 of the susceptor 800. Each of the outlet openings 804 and corresponding flow conduits allows gas to flow from the purge gas region 158 of the chamber volume 123 into the pocket 803 of the susceptor 800. Except for the patterned arrangement of the openings 804, the susceptor 800 shown in FIGS. 8A and 8B may be formed generally similar to the exemplary susceptor 400 shown in FIG. 4 . Accordingly, each of the outlet openings 804 of the plurality of flow conduits extends through the susceptor 800 to a corresponding inlet opening in the bottom surface of the susceptor 800.

[0067] As shown, the various outlet openings 804 of each of the plurality of flow conduits within the susceptor 800 are configured to provide a variable flow of gas to various portions of the susceptor 800 and to any substrate 108 (when disposed on the susceptor 800) therein. In addition to arranging the outlet openings 804 of the plurality of flow conduits in a spiral pattern, in other embodiments, the diameters of the plurality of outlet openings 804 may also vary, with the outlet openings 804 closer to the periphery of the pocket 803 being larger compared to the outlet openings 804 closer to the central region 807 of the pocket 803 of the susceptor 800. Thus, in the illustrated example, the spiral pattern of outlet openings 804 may be formed by arranging multiple intertwined lines 808 of outlet openings 804 radiating from the central region 807 of the pocket 803 of the susceptor 800. In each of the radial lines 808 , the plurality of outlet openings 804 may be formed such that the diameter of the plurality of outlet openings 804 increases from a central region 807 of the pocket 803 towards the outer edge of the pocket 803 .

[0068] When the substrate 108 is placed on the susceptor 800 in the chamber volume 123 for processing, the substrate 108 may generally be positioned and centered within the pocket 803 over the central region 807. However, when the substrate 108 is misaligned within the pocket 803, the substrate 108 is misaligned relative to the central region 807. When such misalignment is detected by the camera 200, the feedback system can initiate one of the methods described herein to automatically move the substrate 108 to correct the misalignment without user intervention. With respect to the susceptor 800, automatically correcting the misalignment includes flowing gas through the multiple flow conduits to lift and reposition the substrate 108 over the central region 807 of the pocket 803.

[0069] The diameters of the outlet openings 804 of the plurality of flow conduits may vary between the central region 807 and the outer periphery of the pocket 803, such that when gas is supplied and the flow conduits are in use, the flow rate of gas through some openings 804 may be different compared to other openings 804. Varying the diameter of the outlet openings 804 may allow for different gas flow rates to particular portions of the pocket 803 near the outer periphery of the susceptor 800. In some embodiments, increasing the gas flow rate through openings 804 near the outer periphery of the pocket 803 may allow for a greater gas flow to assist in lifting a substrate 108 disposed over such openings 804.

[0070] 8B , the spiral pattern design and increased diameter of the plurality of outlet openings 804 near the outer edge of the pocket 803 allows for a greater flow of gas to a particular offset portion of the substrate 108 when the substrate 108 is positioned on the susceptor 800 and is misaligned relative to the central region 807. As shown in FIG. 8B , the portion of the substrate 108 that is misaligned relative to the central region 807 tends to be positioned over more and larger outlet openings 804 of the susceptor 800 compared to the portion of the substrate 108 above the central region 807 and / or the portion opposite the misaligned portion that is closer to the central region 807 accordingly. The greater the misalignment of the substrate 108, the greater the number of outlet openings 804 that the substrate 108 may be positioned over.

[0071] By positioning the offset portion of the substrate 108 over more flow conduits 802 and larger exit openings 804, the susceptor 800 allows the feedback system to provide a greater gas flow to specifically lift and move the offset portion of the substrate 108.

[0072] While the forgoing description is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, the scope of which is defined by the following claims.

Claims

1. 1. A processing system for automatically centering a substrate within a process chamber, comprising: a process chamber including a substrate support disposed within a chamber volume of the process chamber, the substrate support including a pocket for receiving a substrate; a plurality of flow conduits extending between a top surface of the pocket of the substrate support and a bottom surface of the substrate support; an imaging device coupled to the process chamber and configured to monitor the position of the substrate within the pocket of the substrate support; A processing system comprising:

2. 10. The processing system of claim 1, wherein each of said plurality of flow conduits further comprises a flow valve for controlling the flow rate of gas through said plurality of flow conduits.

3. The processing system of claim 1 , wherein the imaging device is configured to detect misalignment of the substrate relative to a center position of the pocket of the substrate support.

4. 2. The processing system of claim 1, wherein each of said plurality of flow conduits is configured to direct a flow of gas from said chamber volume towards said top surface of said pocket.

5. 2. The treatment system of claim 1, wherein each of the plurality of flow conduits includes an outlet opening formed in the upper surface of the pocket, the outlet openings of the plurality of flow conduits being formed between a central region of the pocket and a peripheral edge of the pocket.

6. 6. The treatment system of claim 5, wherein each of the outlet openings of the plurality of flow conduits has a diameter, the diameter of the outlet openings closer to the central region of the pocket being smaller than the diameter of the outlet openings further from the central region.

7. 6. The treatment system of claim 5, wherein said outlet openings of said plurality of flow conduits are arranged in a spiral pattern on said top surface of said pocket.

8. 10. The processing system of claim 1, further comprising a controller communicatively connected to the imaging device and the substrate support, the controller configured to provide a flow of gas through at least some of the plurality of flow conduits in response to detection by the imaging device of a misalignment of the substrate within the pocket of the substrate support.

9. 10. The processing system of claim 1, further comprising a CPU communicatively connected to the imaging device and configured to provide instructions for a recommended adjustment in response to a misalignment of the substrate being detected by the imaging device, the recommended adjustment correcting the misalignment of the substrate detected by the imaging device.

10. 10. The processing system of claim 9, further comprising a controller communicatively connected to the imaging device and the substrate support, the controller configured to provide a flow of gas through at least some of the plurality of flow conduits to move the substrate based on the instructions for the recommended adjustment.

11. 1. A processing system for automatically centering a substrate within a process chamber, comprising: a process chamber including a susceptor and a preheat ring disposed within a chamber volume of the process chamber, the susceptor including a pocket for receiving a substrate, and the preheat ring radially overlapping the susceptor; a plurality of flow conduits extending through portions of the susceptor; an imaging device coupled to the process chamber and configured to monitor a substrate in the pocket of the susceptor; A processing system comprising:

12. 12. The processing system of claim 11, wherein the radially overlapping portion of the preheat ring is disposed above the radially overlapping portion of the susceptor.

13. 12. The processing system of claim 11, wherein each of the plurality of flow conduits is configured to flow gas from the chamber volume into the pocket of the susceptor when the susceptor is lowered relative to the preheat ring.

14. 12. The processing system of claim 11, further comprising a controller communicatively connected to the imaging device and the susceptor, the controller configured to lower the susceptor relative to the preheat ring in response to the imaging device detecting misalignment of the substrate within the pocket of the susceptor.

15. 12. The processing system of claim 11, further comprising a CPU communicatively coupled to the imaging device and configured to provide instructions for a recommended adjustment in response to a misalignment of the substrate being detected by the imaging device, the recommended adjustment correcting the misalignment of the substrate detected by the imaging device.

16. 1. A method for automatically centering a substrate in a process chamber, comprising: Detecting misalignment of a substrate loaded on a substrate support disposed within a chamber space of a process chamber; determining a recommended adjustment for the substrate to correct the detected misalignment; providing a gas flow from the chamber volume to the substrate support based on the recommended adjustment; detecting a corrected position of the substrate on the substrate support, the corrected position corresponding to a center position of the substrate support; stopping the gas flow to the substrate support to set the substrate in the corrected position on the substrate support; A method comprising:

17. 17. The method of claim 16, further comprising continuously monitoring a position of the substrate on the substrate support after providing a gas flow to the substrate support to detect a change in the position of the substrate relative to the substrate support.

18. 17. The method of claim 16, wherein determining a recommended adjustment to correct the misalignment of the substrate comprises determining a recommended adjustment to move the substrate to a center position of the substrate support.

19. 17. The method of claim 16, wherein providing a gas flow to the substrate support comprises flowing gas through a plurality of flow conduits disposed within the substrate support, the plurality of flow conduits directing gas from a purge gas region of the chamber volume below the substrate support, through the substrate support, and onto a top surface of the substrate support.

20. 17. The method of claim 16, wherein the substrate support includes a susceptor and a preheat ring radially overlapping the susceptor, and supplying a gas flow to the substrate support includes lowering the susceptor relative to the preheat ring to allow gas from the chamber space to flow through a plurality of flow conduits extending through the susceptor to an upper surface of the susceptor.

Images