Method and apparatus for calibrating substrate processing chamber placement via imaging

Abstract

An apparatus, method, and system for calibrating substrate positioning and placement on a substrate support in a process chamber via imaging. In one embodiment, a calibration substrate is provided. The calibration substrate generally includes a top surface having a plurality of first marking features and a second marking feature configured to be detectable by an imaging device relative to a remainder of the top surface of the body.

Description

Technical Field

[0001] The present disclosure relates to semiconductor manufacturing and processing. More particularly, the present disclosure relates to methods, apparatus, and systems for fabricating devices on semiconductor substrates. Specifically, embodiments of the present disclosure provide methods, apparatus, and systems for calibrating substrate positioning and placement in a process chamber via imaging. Background Art

[0002] Multi-chamber semiconductor manufacturing systems, which integrate multiple process chambers, are used to process substrates for semiconductor device manufacturing. In multi-chamber manufacturing systems, substrates can be transferred from a substrate load lock chamber to a process chamber equipped with a transfer robot for processing. One of the challenges of substrate handling and positioning is the need to accurately locate the center of the substrate to allow it to be accurately placed on a substrate support in the process chamber.

[0003] As an example of the importance of placement accuracy, a substrate support (e.g., a susceptor) used to hold a substrate in a process chamber typically includes a recess in which the substrate is placed. For a given substrate, the diameter of the recess on the susceptor into which the substrate fits is typically only slightly larger than the diameter of the substrate. There is often minimal clearance between the edge of the substrate and the edge of the susceptor recess. Therefore, it is important that the substrate is centered in the recess so that it does not contact the sidewalls of the susceptor recess. If the substrate contacts the sidewalls of the recess, localized temperature variations will occur, resulting in a temperature gradient across the substrate. This can lead to uneven process results.

[0004] Centering and placement of a substrate on a base is often achieved by confirming that the center of the substrate coincides with the center of the rotating base. Existing methods for finding the center of the substrate typically rely on image processing and detection of the substrate edge and / or the gap between the substrate edge and the base. As the substrate and base rotate on the base, the substrate edge or gap is captured incrementally. Methods using edge shadows and / or reflections typically rely on similar principles. A matrix of images of edge positions and rotation angles is used as input to an algorithm that determines the mathematical center of the substrate. Due to the computational requirements, such methods may require relatively high image processing power and resources and may be time-consuming. In addition, such methods may also have accuracy limitations. For example, the light from the light source used to image the substrate position may have dispersion effects, resulting in a distorted image of the substrate edge being captured. Additional inaccuracies in the image may arise from movement of the light detector or the substrate. Therefore, such inaccurate position readings may produce inaccurate results in determining the center and orientation of the substrate.

[0005] Other attempts, including commercial off-the-shelf hardware, have employed lasers to detect substrate edges through reflection or dispersion. These methods are slightly better at detecting the edges of transparent substrates, but raise significant regulatory and safety concerns and are expensive to implement. Furthermore, fully integrating these systems into substrate chambers or equipment is challenging, making adaptation and installation problematic, with the exception of simple sensor arrays. These systems are also extremely difficult to tune.

[0006] Therefore, there is a need for improved methods, apparatus, and systems for aligning and positioning substrates in a process chamber. Summary of the Invention

[0007] Embodiments of the present disclosure provide methods, apparatus, and systems for calibrating substrate positioning and placement in a process chamber via imaging. In some embodiments, a method for analyzing the placement of a calibration substrate in a process chamber is provided. The method includes placing a calibration substrate on a substrate support in a process chamber using a transfer robot. The calibration substrate includes a plurality of marking features and at least one edge marking feature on a top surface of the calibration substrate. The plurality of marking features and the at least one edge marking feature are configured to be detectable by an imaging device coupled to the process chamber. The method proceeds to capture one or more images of the calibration substrate and the substrate support using the imaging device. The one or more images show a plurality of marking features on the calibration substrate relative to one or more predefined features on the substrate support, the one or more predefined features being positioned at predetermined positions on the substrate support. The one or more images are analyzed to determine a center of the substrate support and a true center of the calibration substrate.

[0008] In other embodiments, a calibration substrate for use in a process chamber is provided. The calibration substrate includes a circular body having a top surface and a circumference. A plurality of first marking features are disposed on the top surface of the body, and a second marking feature is disposed on the top surface of the body along a portion of the circumference. The plurality of first marking features and the second marking feature are configured to be detectable by an imaging device relative to a remaining portion of the top surface of the body.

[0009] In a further embodiment, a processing system for analyzing a calibration substrate in a process chamber is provided. The processing system includes a process chamber having a processing volume and a substrate support disposed in the processing volume. The system also includes a calibration substrate placed on the substrate support by a transfer robot and an imaging device coupled to the process chamber and connected to a controller. The controller includes instructions that, when executed, cause the imaging device to capture one or more images of the calibration substrate and the substrate support. The one or more images show a plurality of marking features on the calibration substrate relative to one or more predefined features on the substrate support, the one or more predefined features being disposed at predetermined locations on the substrate support. The controller also includes instructions that, when executed, cause a processor to determine a true center of the calibration substrate and a center of the substrate support using the one or more images. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order that the manner in which the above-mentioned features of the present disclosure can be understood in detail, the disclosure briefly summarized above may be described in more detail with reference to embodiments, some of which are shown in the accompanying drawings. It should be noted, however, that the drawings illustrate only exemplary embodiments and are therefore not to be considered as limiting the scope of the present disclosure, and other equally effective embodiments may be admitted.

[0012] It is to be noted, however, that the appended drawings illustrate only typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.

[0013] Figure 1 is a schematic cross-sectional side view of a process chamber according to certain embodiments of the present disclosure.

[0014] Figure 2A Shown is a top view of an example calibration substrate according to certain embodiments of the present disclosure.

[0015] Figure 2B A schematic diagram showing a substrate support disposed on a substrate support according to certain embodiments of the present disclosure. Figure 2A Top view of the calibration substrate in .

[0016] Figure 3 is placed by the transfer robot according to some embodiments of the present disclosure Figure 1 Flowchart of a method for calibrating a substrate in a process chamber.

[0017] Figure 4 is a schematic cross-sectional side view of a processing system according to certain embodiments of the present disclosure.

[0018] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation. DETAILED DESCRIPTION

[0019] Reference will now be made in detail to the embodiments, examples of which are illustrated in the accompanying drawings, which show some, but not all, embodiments. Indeed, the concepts may be embodied in many different forms and should not be construed as limiting herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Whenever possible, the same reference numerals are used to refer to the same components or parts.

[0020] The present disclosure relates generally to a substrate processing system, and more particularly to methods, apparatus, and systems for facilitating the positioning, setup, and monitoring of substrates in a process chamber. In semiconductor manufacturing, prior to processing a substrate in a process chamber, the setup process of the process chamber typically includes analyzing the placement of the substrate relative to a substrate support to ensure that the positioning of the substrate by a transfer robot is appropriate and optimal for processing. Proper positioning of the substrate by the transfer robot includes ensuring that the substrate is centered on the substrate support such that the center of the substrate coincides with the center of the substrate support. The placement of the substrate on the substrate support by the transfer robot can be analyzed by processing images of the substrate and substrate support captured by a camera coupled to the process chamber. As mentioned above, analyzing the placement and position of the substrate includes determining the center of the placed substrate based on the captured image for comparison with the center of the substrate support. If it is determined that the positioning of the center of the substrate obtained based on the captured image is different from the center of the substrate support holding the substrate, the placement of the substrate by the transfer robot can be adjusted and corrected accordingly.

[0021] Embodiments disclosed herein include a calibration substrate for use during setup of a process chamber. The calibration substrate can help ensure proper substrate placement by a transfer robot during a process chamber calibration operation prior to processing by facilitating substrate center detection and correction. The calibration substrate includes a plurality of marking features, each marking feature having a predetermined and known size and position on the calibration substrate. The plurality of marking features can be configured to be detectable by an imaging device (e.g., a camera) coupled to the process chamber. When the detected plurality of marking features are observed and analyzed relative to one or more defining features on a substrate support and / or preheat ring in the process chamber that also have a known size and position, data about the calibration substrate and the substrate support can be obtained for determining the position of the center of a placed calibration substrate, the position of the center of a substrate support holding the calibration substrate, the rotation angle of the calibration substrate and the substrate support, a reference metric for direct scaling at the substrate level in a captured image, and any offset between the calibration substrate and the substrate support that needs to be corrected, among other things.

[0022] Typically, a processing system has a centralized transfer chamber mounted on a monolithic platform. The transfer chamber is the active hub for the movement of substrates being processed in the system. One or more process chambers are attached to the transfer chamber at slit valves, through which substrates are transferred by a substrate handler or transfer robot. Access to the transfer chamber is typically from a clean ambient environment via one or more load lock chambers attached to other slit valves. The load lock chambers can lead to an extremely clean room (called a white zone) or to an optional substrate handling chamber (often called a microenvironment).

[0023] Figure 1 FIG2 is a schematic cross-sectional side view of a process chamber 100 according to certain embodiments. The process chamber 100 is a deposition chamber. In one embodiment, which may be combined with other embodiments, the process chamber 100 is an epitaxial deposition chamber. The process chamber 100 is used to grow an epitaxial film on a substrate 108. The process chamber 100 generates a crossflow of precursors across the top surface of the substrate 108.

[0024] The process chamber 100 may include an array of radiant heat lamps 102 for heating a substrate support 106 (e.g., which may be a susceptor) and other components disposed within the process chamber 100. In some embodiments, the array of radiant heat lamps may be disposed above an upper dome 128. The substrate support 106 may be a dish-shaped substrate support 106 as shown, or may be an annular substrate support 107 without a central opening that supports the substrate from its edge to facilitate exposure of the substrate to thermal radiation from the lamps 102.

[0025] As shown, a controller 120 and a camera 166 are in communication with the process chamber 100. The controller 120 can be used to control processes and methods, such as the operations of the methods described herein. The camera 166 can be used to capture images of the substrate 108 and / or components (such as a calibration substrate) used in processes and methods (such as the operations of method 300 described herein) within the process chamber 100. The controller 120, camera 166, and process chamber 100 can be part of a substrate processing system.

[0026] The substrate support 106 is positioned within the process chamber 100 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 an interior region of the process chamber 100. A substrate 108 (not to scale) may be brought into the process chamber 100 via a loadport 103 and positioned onto the substrate support 106.

[0027] The substrate support 106 is shown in a raised processing position, but can be vertically transversely moved by an actuator (not shown) to a loading position below the processing position to allow the lift pins 105 to contact the lower dome 114, pass through the holes in the substrate support 106 and the central shaft 132, and lift the substrate 108 from the substrate support 106. A robot (not shown) can then enter the process chamber 100 to engage the substrate 108 and remove it via the loadport 103. The substrate support 106 can then be actuated upward to the processing position to place the substrate 108 on the top surface 110 of the substrate support 106 with the device side 116 of the substrate facing upward.

[0028] When in the processing position, the substrate support 106 divides the interior volume of the process chamber 100 into a process gas zone 156 above the substrate and a purge gas zone 158 below the substrate support 106. The substrate support 106 rotates during processing by the central axis 132 to minimize the effects of thermal and process gas flow spatial anomalies within the process chamber 100 and thereby promote uniform processing of the substrate 108. The substrate support 106 is supported by the central axis 132, which moves the substrate 108 in an up-down direction 134 during loading and unloading, and in some cases during processing of the substrate 108. The substrate support 106 may be formed of silicon carbide or graphite coated with silicon carbide to absorb radiant energy from the lamps 102 and conduct the radiant energy to the substrate 108.

[0029] Typically, the central window portion of the upper dome 128 and the bottom of the lower dome 114 are formed of an optically transparent material such as quartz. "Optically transparent" here means generally transparent to radiation, but not necessarily 100% transparent. As will be described below, Figure 1 As discussed in more detail, the thickness and curvature of the upper dome 128 may be configured in accordance with the present invention to provide a flatter geometry for achieving uniform flow uniformity within the process chamber.

[0030] One or more lamps, such as an array of lamps 102, may be positioned adjacent to and beneath the lower dome 114 in a designated pattern about the central axis 132 to independently control the temperature at various regions of the substrate 108 as process gases pass therethrough, thereby facilitating deposition of material onto the upper surface of the substrate 108. Although not discussed in detail herein, the deposited material may include gallium arsenide, gallium nitride, or aluminum gallium nitride, among other materials.

[0031] The lamps 102 can be configured to include bulbs and are configured to heat the substrate 108 to a temperature in the range of about 200 degrees Celsius to about 1600 degrees Celsius. Each lamp 102 is coupled to a power distribution board (not shown), via which power is supplied to each lamp 102. The lamps 102 are located within a lamp head 145, which can be cooled during or after processing by, for example, a cooling fluid introduced into a channel 149 located between the lamps 102. In part due to the close proximity of the lamp heads 145 to the lower dome 114, the lamp heads 145 cool the lower dome 114 by conduction and radiation. The lamp heads 145 can also cool the lamp walls and the walls of a reflector (not shown) surrounding the lamp. Alternatively, the lower dome 114 can be cooled by convection. Depending on the application, the lamp heads 145 may or may not contact the lower dome 114.

[0032] A circular shroud 167 may optionally be positioned around the substrate support 106 and surrounded by the liner assembly 163. The shroud 167 prevents or minimizes heat / light noise leakage from the lamps 102 to the device side 116 of the substrate 108 while providing a preheat zone for the process gases. The shroud 167 may be made of CVD SiC, sintered graphite coated with SiC, grown SiC, opaque quartz, coated quartz, or any similar suitable material that resists chemical breakdown by the process and purge gases.

[0033] The liner assembly 163 is sized to nest within, or be surrounded by, the inner circumference of the base ring 136. The liner assembly 163 shields the processing volume (i.e., the process gas region 156 and the purge gas region 158) from the metal walls of the process chamber 100. The metal walls can react with the precursors and cause contamination within the processing volume. While the liner assembly 163 is shown as a single body, the liner assembly 163 may include one or more liners having different configurations.

[0034] Because the substrate support 106 heats the substrate 108, the optical pyrometer 118 can be used to perform temperature measurement / control of the substrate support 106. Such temperature measurements by the optical pyrometer 118 can also be performed on the substrate device side 116, where the emissivity is unknown, since heating the substrate top surface 110 in this manner is independent of emissivity. Thus, the optical pyrometer 118 can only sense radiation from the hot substrate 108 that is conducted through the substrate support 106, while minimal background radiation from the lamp 102 directly reaching the optical pyrometer 118.

[0035] A reflector 122 may optionally be positioned outside the upper dome 128 to reflect infrared light radiating from the substrate 108 back onto the substrate 108. The reflector 122 may be secured to the upper dome 128 using a clamping 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 high-reflectivity coating such as gold. The reflector 122 may have one or more conduits 126 connected to a cooling source (not shown). The conduits 126 are connected to channels (not shown) formed on one side of the reflector 122. The channels are configured to carry a flow of a fluid, such as water, and may be arranged 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.

[0036] A process gas supplied from a process gas supply 172 is introduced into the process gas region 156 via a process gas inlet 174 formed in a 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 the film formation process, the substrate support 106 can be positioned in a processing position adjacent to and at approximately the same height as the process gas inlet 174, allowing the process gas to flow in a laminar manner along a flow path 173 upward and around the upper surface of the substrate 108. The process gas exits the process gas region 156 (along a flow path 175) via a gas outlet 178 located on a side of the process chamber 100 opposite 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 the gas outlet 178 are aligned with each other and disposed at approximately the same height, it is believed that such a parallel arrangement, when combined with the flatter upper dome 128 (as discussed in detail below), will achieve a substantially flat, uniform gas flow across the substrate 108. Further radial uniformity can be provided by rotation of the substrate 108 via the substrate support 106.

[0037] Controller 120 includes a central processing unit (CPU), a memory containing instructions, and support circuits for the CPU. Controller 120 controls various items directly or via other computers and / or controllers. In one or more embodiments, controller 120 is communicatively coupled to a dedicated controller, and controller 120 serves as a central controller.

[0038] The controller 120 is any form of general-purpose computer processor used in an industrial environment for controlling various substrate processing chambers and equipment and the sub-processors thereon or therein. The memory or non-transitory computer-readable medium is one or more of readily available memory such as random access memory (RAM), dynamic random access memory (DRAM), static RAM (SRAM), and synchronous dynamic RAM (SDRAM (e.g., DDR1, DDR2, DDR3, DDR3L, LPDDR3, DDR4, LPDDR4, etc.), read-only memory (ROM), floppy disk, hard disk, flash drive, or any other form of local or remote digital storage. The support circuits of the controller 120 are coupled to the CPU to support the CPU (processor). The support circuits include cache, power supplies, clock circuits, input / output circuitry and subsystems, etc. Operating parameters (such as the temperature of the substrate 108, the temperature of the substrate support 106, and / or the pressure and / or temperature of the process gas) and operations are stored in the memory as software routines that are executed or called to transform the controller 120 into a dedicated controller to control the operation of the various chambers / modules described herein. The controller 120 is configured to perform any of the operations described herein.When executed, the instructions stored on the memory cause one or more of the operations of the method 300 (described below) to be performed.

[0039] Various operations described herein, such as the operations of method 300 , may be performed automatically using controller 120 , or may be performed automatically or manually by certain operations performed by a user.

[0040] The controller 120 is configured to control the camera and rotational positioning in the process chamber 100 by providing outputs to controls for the heat sources 141, 143, gas flows, and the motion assembly 121. The controls include controls for the upper heat source 141, the lower heat source 143, the process gas source 151, the purge gas source 162, the motion assembly 121, and the exhaust pump 157.

[0041] The controller 120 is configured to adjust the output of the control device based on sensor readings, system models, and stored readings and calculations. The controller 120 includes embedded software and compensation algorithms for calibrating the measurement results. The controller 120 may include one or more machine learning algorithms and / or artificial intelligence algorithms to estimate optimized parameters for the deposition operation, the purge operation, and / or the cleaning operation. For example, the one or more machine learning algorithms and / or artificial intelligence algorithms may use a regression model (such as a linear regression model) or clustering techniques to estimate the optimized parameters. The algorithms may be unsupervised or supervised.

[0042] Substrates (including calibration substrates) may be transferred into and out of the interior volume of the process chamber 100 via a transfer door 137 (such as a slit valve). When the transfer door 137 is open, a transfer robot (with a substrate positioned thereon) may be extended into the interior volume through the transfer door 137 so that the lift pins 105 may lift the substrate from the transfer robot and place it on the substrate support 106 for processing. After processing, the lift pins 105 may lift the substrate from the substrate support 106 and place it back on the transfer robot, and the transfer robot may be retracted through the open transfer door 137 to remove the substrate from the process chamber 100.

[0043] As discussed above, systems and methods are provided herein for calibrating the placement and positioning of substrates by a transfer robot in a process chamber using a plurality of marking features disposed on a calibration substrate via image processing. Processing of images of a substrate support and the calibration substrate thereon can also be used to assist in detecting rotation, angle, and gap between the edge of the calibration substrate and the substrate support. Thus, an image of a calibration substrate disposed within the process chamber 100 can be captured using a visualization system comprising an imaging device (e.g., such as a Figure 1 The camera 166 is shown, located within a process chamber (such as process chamber 100, for example), or located outside the chamber but with a view through an aperture in the chamber.

[0044] like Figure 1 As shown, the process chamber 100 may include a camera 166 for observing the substrate 108, the substrate support 106, and / or a preheat ring coupled to the substrate support 106 (not shown) in the process chamber 100. The camera 166 may be positioned above the top of the process chamber 100, and a collection device for the camera (e.g., a light pipe) may be placed through the top of the process chamber 100 into the process gas region 156. Alternatively, the camera 166 may be positioned within the process chamber 100. For example, the camera 166 may be placed in an opening 186 in the upper dome 126 between the upper dome 128 and the reflector 122. The camera 166 or a collection device for the camera may be placed through a port for connecting the conduit 126 to the process chamber 100, or alternatively, the camera 166 may be coupled to the chamber using a frame. The camera 166 may be capable of operating in a vacuum or at atmospheric pressure. A camera 166 may be positioned within the process chamber 100 to capture images of the substrate 108, edge ring, mask, and / or substrate support 106. The position of the camera 166 relative to the upper dome 128 and substrate support 106, as well as the optical characteristics of the camera 166, may be determined to ensure that the field of view includes the region of interest on the substrate support 106.

[0045] The camera 166 may be electrically coupled to the controller 120, which controls the operation of the camera 166 (e.g., on / off, focusing, image capture, etc.). It should be noted that the camera 166 is only one example of a device that may be used to image the calibration substrate and substrate support, and any other type of imaging device may be used as a position detection device. In some embodiments, more than one camera may be used to capture images of the substrate support 106. In some embodiments, the camera 166 is an image capture device that may include a high-efficiency, low-voltage complementary metal oxide semiconductor (CMOS) sensor and, thus, may function as a single-chip video camera. The CMOS sensor may be of the VGA type. The camera 166 may include a lens, such as a wide-angle lens or a plano-convex lens with an appropriate focal length, that provides sufficient visual clarity within the desired operating range of the camera 166. It will be apparent to those skilled in the art that different lenses (e.g., telescopic or rotating prism lenses) may be used for different applications. It will also be appreciated that other types of cameras or optical sensors may be used, including but not limited to SVGA, XGA, or MEGA pixel cameras, or other image capture devices. If desired, multiple image capture devices of different resolution types may be used in combination with lenses of different types or focal lengths. The camera or sensor may be of static (still) or dynamic (video) type, and may be of charge coupled device (CCD) type. Additionally, the camera 166 may be used to output the video signal to any standard TV format.

[0046] Figure 2A A top view of an example calibration substrate 200 that can be used in accordance with the methods and operations disclosed herein, according to certain embodiments of the present disclosure, is shown. The calibration substrate 200 can be handled by a transfer robot and placed on a substrate support 106 in the process chamber 100. The calibration substrate 200 can be formed similarly to a device (e.g., a wafer, a substrate) handled by the transfer robot and processed by the process chamber 100. In certain embodiments, the calibration substrate 200 can include a body having a circular shape and a notch aligner (not shown) to properly align the calibration substrate 200 to an alignment point of the transfer robot. The alignment point can be a corresponding hole or recess on the transfer robot for mating with a notch aligner in the calibration substrate 200. The notch aligner can help provide consistent handling of the calibration substrate 200 by the transfer robot.

[0047] The calibration substrate 200 includes a top surface 202 having a plurality of marking features 204 formed thereon. The plurality of marking features 204 on the calibration substrate 200 can facilitate calibration of substrate placement by a transfer robot. In certain embodiments, the plurality of marking features 204 can facilitate determining the center position of the calibration substrate 200 placed by the transfer robot, as well as the center position of the substrate support 106 holding the calibration substrate 200. The center positions of the calibration substrate 200 and the substrate support 106 can then be used to determine a calculated offset between the calibration substrate 200 and the substrate support 106 that requires correction. In certain embodiments, the calibration substrate 200 can also include at least one edge marking feature 206 formed along a circumference of the calibration substrate 200. The at least one edge marking feature 206 can facilitate determining a corresponding rotation angle and rotation angle correlation when analyzing a captured image of the calibration substrate 200 within the process chamber 100.

[0048] In some embodiments, which may be combined with other embodiments herein, the plurality of marking features 204 may be any type of marking that can be placed or formed on the top surface 202 of the calibration substrate 200 and detected by the camera 166 for image analysis. In some embodiments, which may be combined with other embodiments discussed herein, the plurality of marking features 204 may be surface features formed on the top surface 202 of the calibration substrate 200. In other embodiments, the plurality of marking features 204 may be surface features etched into the top surface 202 of the calibration substrate 200. In certain embodiments, the markings of the plurality of marking features 204 may include any number, letters, symbols, shapes, or patterns, including but not limited to bar codes, numeric codes, alphanumeric codes, QR codes, custom shapes, shape patterns, symbol patterns, character strings, special characters, and the like. Figure 2A In the example shown, the plurality of marking features 204 are formed as circles on a portion of an edge 207 of the calibration substrate 200 , and at least one edge marking feature 206 is formed as a curved arc along the portion.

[0049] In order to use the plurality of mark features 204 including the at least one edge mark feature 206 as relative reference points in a captured image of the calibration substrate 200, the plurality of mark features 204 and the at least one edge mark feature 206 may be formed at predetermined sizes and positions on the top surface 202 of the calibration substrate 200. By forming the plurality of mark features 204 with known sizes, the plurality of mark features 204 may also be used to provide a reference metric for direct scaling at the substrate level in a captured image of the calibration substrate 200.

[0050] Figure 2B Display according to some embodiments Figure 1 on the substrate support in the process chamber Figure 2A1. A top view of a calibration substrate 200 is provided. When the calibration substrate 200 is positioned within the process chamber 100, an image of a plurality of mark features 204 and at least one edge mark feature 206 on the calibration substrate 200 can be captured by the camera 166 and analyzed to determine the placement, rotation, and / or positioning of the calibration substrate 200 relative to the substrate support 106 in the process chamber 100. When an image of the calibration substrate 200 positioned on the substrate support 106 in the process chamber is obtained, the plurality of mark features 204 in the image of the calibration substrate 200 can be detected and analyzed. Performing image analysis on such an image enables the positions of the plurality of mark features 204 to be determined as coordinate points on the top surface 202 of the calibration substrate 200 relative to one or more predefined features 208 on the substrate support 106 and / or the preheat ring in the process chamber 100. The positions of the plurality of mark features 204 can then be used to determine the true center of the calibration substrate 200. Thus, being able to use multiple marker features 204 detected in an image obtained by the camera 166 may advantageously enable more efficient and accurate determination of the true center of the calibration substrate 200 via imaging.

[0051] While some examples described herein apply a plurality of marking features 204 to a calibration substrate 200, the embodiments of the present disclosure described herein with respect to forming marking features 204 on a calibration substrate 200 may be similarly applied to applying one or more predefined features 208 to a substrate support 106 and / or a preheat ring in a process chamber 100. Thus, in some embodiments, similar to the formation of the plurality of marking features 204 formed on the calibration substrate 200 discussed herein, one or more predefined features 208 may be formed on the substrate support 106 and / or the preheat ring. In other embodiments, the one or more predefined features 208 on the substrate support 106 and / or the preheat ring holding the calibration substrate 200 may be digitally implemented on an image of the substrate support 106 and / or the preheat ring captured by the camera 166.

[0052] like Figure 2BAs shown, one or more predefined features 208 may be formed on the top surface of the substrate support 106 and / or the preheat ring. The one or more predefined features 208 may be formed on portions of the substrate support 106 and / or the preheat ring at predetermined locations within the field of view of the camera 166. The one or more predefined features 208 captured in an image of the calibration substrate 200 and the plurality of marking features 204 formed thereon may be used as reference points for analyzing the placement and positioning of the calibration substrate 200 on the substrate support 106. The one or more predefined features 208 on the substrate support 106 and / or the preheat ring in the process chamber 100 may be used to define a coordinate system 212 for determining the coordinates of a center 214 of the substrate support 106 and the relative positioning of the calibration substrate 200 on the substrate support. In certain embodiments where the calibration substrate 200 is received in a recess in the substrate support 106, the center 214 of the substrate support 106 may correspond to the center of the recess in the substrate support 106.

[0053] When the calibration substrate 200 is placed on the substrate support 106, the coordinates of each of the plurality of mark features 204 can be determined using the same coordinate system 212 that is used as a relative reference point by one or more predefined features 208 on the substrate support 106 and / or the preheat ring. To facilitate determining the center position of the calibration substrate 200 placed on the substrate support 106, the plurality of mark features 204 on the calibration substrate 200 can include a sufficient number of mark features 204 (e.g., at least six mark features 204 representing six coordinate points on the calibration substrate 200) to determine a mathematical representation of at least three chords 216, each chord extending across a diameter of the calibration substrate 200. The three chords 216 can then be used to determine the coordinates corresponding to the true center 218 of the calibration substrate 200. The coordinates of the true center 218 of the calibration substrate 200 can then be compared to the previously determined coordinates of the center 214 of the substrate support 106 to analyze whether the calibration substrate 200 was properly placed on the substrate support 106 by the transfer robot.

[0054] Advantageously, the plurality of marking features 204 on the calibration substrate 200 and the one or more predefined features 208 on the substrate support 106 and / or preheat ring enable the coordinates of the true center 218 of the calibration substrate 200 and the center 214 of the substrate support 106 to be determined by analyzing a still image of the calibration substrate 200 captured by the camera 166, rather than relying on the rotational images required for gap detection. This reduces the need for cumbersome image processing, which may also require additional corresponding data regarding the rotation angles and correlations of the respective rotated images, without having to analyze a series of images of the calibration substrate 200 rotated by the substrate support 106.

[0055] In certain embodiments, the at least one edge mark feature 206 includes a curved design formed along a portion of an edge 207 of the calibration substrate 200. The curved design along the edge 207 of the calibration substrate 200 can be used to determine the rotation angle of the calibration substrate 200 and the substrate support 106, and the correlation between the rotation angle of the calibration substrate 200 and the substrate support 106 and the home angle via image analysis. Thus, an image of the at least one edge mark feature 206 on the calibration substrate 200 can be used to assist in monitoring the positioning of the calibration substrate 200 as the calibration substrate 200 is rotated to confirm the calculated offset between the calibration substrate 200 and the substrate support 106. For example, the at least one edge mark feature 206 on the calibration substrate 200 can be used to monitor the gap offset via imaging as the calibration substrate is rotated.

[0056] Figure 3 A flow chart illustrating a method 300 for determining the offset of a calibration substrate placed on a substrate support in a process chamber by a transfer robot, according to certain embodiments of the present disclosure. The method 300 may be executed as a software routine by the controller 120 in the substrate processing system. The method 300 may be used to determine and compare the coordinates of the true center 218 of the calibration substrate 200 and the center 214 of the substrate support 106.

[0057] The method 300 begins at operation 302, where a calibration substrate 200 is placed by a transfer robot on a substrate support in a process chamber, such as the substrate support 106 in the process chamber 100. When the calibration substrate 200 is positioned on the substrate support 106, at least some of the plurality of marking features 204 on the calibration substrate 200 and at least some of the one or more pre-defined features 208 on the substrate support 106 may be within a field of view of the camera 166.

[0058] At operation 304, one or more images of the calibration substrate 200 and the substrate support 106 are captured by the camera 166. The one or more images show the position of the plurality of mark features 204 on the calibration substrate 200 relative to the substrate support 106. In some embodiments, all of the mark features 204 on the calibration substrate 200 may be within the field of view of the camera 166 and may be captured in a single still image. In other embodiments, the plurality of mark features 204 may be formed such that only some of the plurality of mark features 204 may be within the field of view of the camera 166 at any one time. In such cases, the camera 166 may be moved and / or adjusted to capture additional images of a particular portion of the calibration substrate 200, thereby imaging any remaining mark features 204 in the plurality of mark features 204 formed on the calibration substrate 200. Alternatively, the calibration substrate 200 may be rotated by the substrate support 106 to move the particular portion of the calibration substrate 200 with the remaining mark features 204 within the field of view of the camera 166 for imaging.

[0059] In some embodiments, the image of the substrate support 106 includes one or more predefined features 208 formed at known locations on the top surface of the substrate support 106. Alternatively, the one or more predefined features 208 may be digitally implemented after the camera 166 acquires the one or more images to facilitate image analysis. In either case, the one or more images may include a display showing the positions of the plurality of marking features 204 relative to the one or more predefined features 208 on the substrate support 106.

[0060] In operation 306, the one or more images captured by the camera 166 may be analyzed to determine the coordinates of the center 214 of the substrate support holding the calibration substrate 200 based on the one or more pre-defined features 208 on the substrate support 106. The one or more pre-defined features 208 on the substrate support 106 may be used to define a coordinate system such that the known positions of the one or more pre-defined features 208 serve as reference points for defining all other positioning coordinates. In some embodiments, a standardized center finder software algorithm, such as a best fit center finder routine, may be used to determine the center of the substrate support 106 based on the known coordinates of the one or more pre-defined features 208 on the substrate support 106.

[0061] In operation 308, the coordinates of the plurality of mark features 204 depicted in the one or more images are determined based on the coordinates of the one or more predefined features 208 used in operation 306. As mentioned above, the one or more predefined features 208 can be used as reference points for defining a coordinate system. The same coordinate system can extend across the top surface of the substrate support 106 so that the coordinate system can be overlaid on the calibration substrate 200 disposed on the top surface of the substrate support 106. The coordinates of each of the plurality of mark features 204 on the same coordinate system can then be determined based on the known coordinates of the one or more predefined features 208 and the position of each of the plurality of mark features 204 relative to the predefined features 208 depicted in the one or more images captured by the camera 166 and detected through image analysis.

[0062] In operation 310, the coordinates of the true center 218 of the calibration substrate 200 are determined based on the coordinates of the plurality of marking features 204. The coordinates of the true center 218 of the calibration substrate 200 may be determined based on the coordinates of the plurality of marking features 204 obtained as described above in operation 306 using the same or similar standardized center finder software algorithm used to determine the coordinates of the center 214 of the substrate support 106. For example, the coordinates of the plurality of marking features 204 on the calibration substrate 200 may be used to create a mathematical representation of at least three chords extending across a diameter of the calibration substrate 200, such as Figure 1 B. The perpendicular lines of the chords can then be checked to determine the intersection of the chords, and the coordinates of the true center 218 of the calibration substrate 200 can be calculated based on the intersection. Thus, the plurality of marking features 204 on the calibration substrate 200 can be analyzed and the true center 217 of the calibration substrate 200 can be determined.

[0063] In operation 312, the coordinates of the true center 218 calculated from operation 310 may be compared to the coordinates of the center 214 of the substrate support 106 to determine whether the coordinates of the two centers are within a predetermined threshold limit of each other. If the calculated coordinates of the calibration substrate 200 and the center of the substrate support 106 are within the threshold limit, the placement of the calibration substrate 200 on the substrate support 106 may be deemed appropriate and / or at least sufficient for performing processing on the substrate in the process chamber 100. In operation 314, if the coordinates of the center of the calibration substrate 200 and the substrate support 106 are outside the threshold limit, an offset correction may be determined based on the difference.

[0064] In operation 316, if it is determined that an offset correction is required, placement of substrates (including the calibration substrate 200 in operation 302) by the transfer robot may be adjusted (to center the substrates on the substrate support 106 by the transfer robot) based on the offset correction determined by the controller 120. For example, the offset correction may be communicated to the transfer robot, which may then adjust programmed substrate handling and placement positions by an amount equal to the offset correction.

[0065] If the calculated offset correction is used to adjust the transfer robot, operations 302 through 310 may be repeated to confirm that the adjustments made using the calculated offset correction are sufficient so that the calculated true center 218 of the calibration substrate 200 placed by the transfer robot is within the threshold limit of the center 214 of the substrate support 106. Once the placement of the calibration substrate 200 by the transfer robot is satisfactorily calibrated, the calibration substrate 200 may be stored in a load lock chamber of the processing system. The method 300 of calibrating substrate placement by the transfer robot may be performed periodically for maintenance and quality control purposes. In some embodiments, the calibration process may be performed more frequently depending on the level of use of the process chamber 100 and whether changes are made to the processing parameters of the process chamber 100 or to the substrates handled for processing by the transfer robot.

[0066] Figure 4 FIG4 is a top plan view of a processing system 400 according to one embodiment. The processing system 400 includes one or more substrate load lock chambers 422, a vacuum-sealed processing platform 404, a factory interface 402, and a controller 444. The substrate load lock chamber 422 can be a load lock chamber. In one embodiment, the processing system 400 can be a commercially available substrate load lock chamber from Applied Materials, Inc., located in Santa Clara, California. Integrated Processing Systems. It is contemplated that other processing systems, including those from other manufacturers, may be adapted to benefit from the present disclosure.

[0067] The platform 404 includes a plurality of processing chambers 410, 412, 428, 420, 432 and one or more substrate load lock chambers 422 coupled to a vacuum substrate transfer chamber 436. One or more of the processing chambers 410, 412, 428, 420, 432 in the processing system 400 may include the process chamber 100. The factory interface 402 is coupled to the transfer chamber 436 via two substrate load lock chambers 422.

[0068] In one or more embodiments, the factory interface 402 includes at least one docking station 408 and at least one factory interface robot 414 to facilitate transfer of substrates. The docking station 408 is configured to accommodate one or more front opening unified pods (FOUPs). Figure 4 In the embodiment shown in FIG. 2 , two FOUPs 406A and 406B are shown. The factory interface robot 414 has a blade 416 mounted on one end of the robot 414. The robot 414 is configured to transfer one or more substrates from the FOUPs 406A and 406B to the processing platform 404 via a substrate load lock chamber 422 for processing. In some embodiments, the transferred substrates may be stored in the substrate load lock chambers 422. In some embodiments, the calibration substrate 200 may also be stored in one of the substrate load lock chambers 422.

[0069] Each of the substrate load lock chambers 422 has a first port that interfaces with the factory interface 402 and a second port that interfaces with the transfer chamber 436. The substrate load lock chambers 422 are coupled to a pressure control system (not shown) that pumps down and evacuates the substrate load lock chambers 422 to facilitate transferring substrates between the vacuum environment of the transfer chamber 436 and the substantially ambient (e.g., atmospheric) environment of the factory interface 402.

[0070] A transfer robot 430 is disposed in the transfer chamber 436. The transfer robot 430 has a blade 434 capable of transferring substrates including the calibration substrate 200 between the substrate load lock chamber 422 and the processing chambers 410, 412, 432, 428, 420.

[0071] A controller 444 is coupled to the processing system 400. The controller 444 controls the operation of the system 400 using direct control of the process chambers 410, 412, 432, 428, 420 of the system 400, or alternatively by controlling computers (or controllers) associated with the process chambers 410, 412, 428, 420, 432 and the system 400. In operation, the controller 444 enables data and feedback to be collected from the individual chambers and the controller 444 to optimize the performance of the system 400.

[0072] Controller 444 is used to control processes and methods, such as the operations of the methods described herein (e.g., the operations of method 300 described above). Controller 444 includes a central processing unit (CPU) 438, a memory 440 containing instructions, and support circuits 442 for the CPU. Controller 444 controls various items directly or via other computers and / or controllers. In one or more embodiments, controller 444 is communicatively coupled to a dedicated controller, and controller 444 serves as a central controller.

[0073] The controller 444 is any form of general-purpose computer processor used in an industrial environment for controlling various substrate processing chambers and equipment and sub-processors thereon or therein. The memory 440 or non-transitory computer-readable medium is one or more of readily available memories such as random access memory (RAM), dynamic random access memory (DRAM), static RAM (SRAM), and synchronous dynamic RAM (SDRAM (e.g., DDR1, DDR2, DDR3, DDR3L, LPDDR3, DDR4, LPDDR4, etc.), read-only memory (ROM), floppy disk, hard disk, flash drive, or any other form of local or remote digital storage device. The support circuit 442 of the controller 444 is coupled to the CPU 438 to support the CPU 438 (processor). The support circuit 442 may include cache, power supply, clock circuit, input / output circuit system and subsystems, etc. Operating parameters (such as UV light power, inert gas temperature, inert gas pressure, native oxide content, particle concentration, and / or atomic particle concentration) and operations are stored in memory 440 as software routines that are executed or called to transform controller 444 into a dedicated controller for controlling the operation of the various systems / chambers / units / modules described herein. When executed by CPU 438, the software routines transform CPU 438 into a dedicated computer. The software routines may also be stored and / or executed by a second controller (not shown) remotely located relative to system 400.

[0074] Controller 444 is configured to perform any of the operations described herein. When executed, the instructions stored on the memory cause one or more of the operations of method 300 (described above) to be performed. The various operations described herein may be performed automatically using controller 444, or may be performed automatically and / or manually through certain operations performed by a user.

[0075] The controller 444 is configured to adjust the output of the control device of the system 400 based on sensor readings, system models, and stored readings and calculations. For example, one or more operating parameters may be measured by one or more sensors positioned along the system 400. The controller 444 includes embedded software and compensation algorithms for calibrating the measurement results. The controller 444 may include one or more machine learning algorithms and / or artificial intelligence algorithms that estimate optimized parameters for deposition operations, cleaning operations, etching operations, and / or atomic radical treatment operations. For example, the one or more machine learning algorithms and / or artificial intelligence algorithms may use regression models (such as linear regression models) or clustering techniques to estimate optimized parameters. The algorithms may be unsupervised or supervised. The one or more machine learning algorithms and / or artificial intelligence algorithms may optimize the operating parameters used with respect to the operations described herein.

[0076] While the embodiments of the present disclosure have been described above with reference to specific embodiments, and numerous specific details have been set forth to provide a more thorough understanding of the present invention, it will be appreciated by those skilled in the art that various modifications and variations may be made without departing from the broader spirit and scope of the present invention. The foregoing description and drawings are therefore to be regarded as illustrative rather than restrictive.

[0077] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope, and the scope is determined by the claims that follow.

Claims

1. A method for analyzing a calibration substrate in a process chamber, the method comprising: placing a calibration substrate on a substrate support disposed in a process chamber using a transfer robot, wherein the calibration substrate includes a plurality of mark features and at least one edge mark feature on a top surface of the calibration substrate, wherein the plurality of mark features and the at least one edge mark feature are configured to be detectable by an imaging device coupled to the process chamber, and wherein the at least one edge mark feature is disposed along a circumference of the calibration substrate; capturing one or more images of the calibration substrate and the substrate support using the imaging device; analyzing the one or more images showing the plurality of marking features on the calibration substrate relative to one or more predefined features on the substrate support, the one or more predefined features disposed at predetermined locations on the substrate support; and The center of the substrate support and the true center of the calibration substrate are determined.

2. The method of claim 1, further comprising: A comparison is made as to whether a difference between the center of the substrate support and the true center of the calibration substrate to be inspected is within predetermined threshold limits to determine whether an offset correction is required.

3. The method of claim 2, further comprising: If it is determined that the offset correction is required, the transfer robot is adjusted based on the offset correction.

4. The method of claim 1 , wherein analyzing the one or more images to determine the center of the substrate support comprises: A center of the substrate support is determined from the one or more images using the predetermined positions of the one or more predefined features.

5. The method of claim 1 , wherein analyzing the one or more images to determine the true center of the calibration substrate comprises: A true center of the calibration substrate is determined from the one or more images using the plurality of marking features and the predetermined positions of the one or more predefined features.

6. The method of claim 1 , wherein analyzing the one or more images to determine the true center of the calibration substrate comprises: A position of each of the plurality of marking features on the calibration substrate is determined from the one or more images using the predetermined positions of the one or more predefined features.

7. The method of claim 6, wherein determining the true center of the calibration substrate further comprises: determining a mathematical representation of at least three chords extending across a diameter of the calibration substrate using the position of each of the plurality of marking features; determining an intersection point of the at least three chords; and The true center of the calibration substrate is determined using the intersection point.

8. The method of claim 1 , wherein capturing one or more images of the calibration substrate and the substrate support comprises: One or more images of the one or more predefined features formed on the top surface of the substrate support are captured.

9. The method of claim 1, further comprising: The one or more predefined features are digitally implemented on the substrate support in the one or more images.

10. The method of claim 1, further comprising: The one or more images from the imaging device are analyzed to determine a rotation angle of the calibration substrate using the at least one edge marking feature.

11. The method of claim 2, further comprising: When it is determined that the offset correction is required, the offset correction is confirmed by monitoring gap offset via imaging using the at least one edge marking feature as the calibration substrate rotates.

12. A calibration substrate for use in a process chamber, the calibration substrate comprising: a circular body having a top surface and a circumference; a plurality of first marking features disposed on the top surface of the body; and a second marking feature disposed on the top surface of the body and extending along a portion of the circumference; Wherein the plurality of first marking features and the second marking features are configured to be detectable by an imaging device relative to the remaining portion of the top surface of the body.

13. The calibration substrate of claim 12, wherein the plurality of first marking features comprises at least six first marking features positioned for determining mathematical representations of at least three chords each extending across a diameter of the body.

14. The calibration substrate of claim 12, wherein the plurality of first marking features and the second marking features comprise known dimensions extending along the top surface of the body, the known dimensions providing direct scaling of the calibration substrate and substrate support in an image of the calibration substrate and substrate support.

15. The calibration substrate of claim 12, wherein the second marking feature provides a reference point for determining a rotation angle of the calibration substrate via imaging.

16. The calibration substrate of claim 12, wherein the plurality of first marking features and the second marking features comprise surface features formed on or etched into the top surface of the body.

17. The calibration substrate of claim 12, wherein the plurality of first marking features comprise markings, shapes, or patterns, including but not limited to custom shapes, patterns of shapes, symbols, and special characters.

18. A processing system for analyzing a calibration substrate in a process chamber, the processing system comprising: a process chamber having a processing volume; a substrate support disposed in the processing volume, the substrate support configured to receive a substrate; a calibration substrate, placed on the substrate support by a transfer robot; An imaging device coupled to the process chamber and connected to a controller, the controller including instructions that, when executed, cause: the imaging device capturing one or more images of the calibration substrate and the substrate support, the one or more images showing a plurality of marking features on the calibration substrate relative to one or more predefined features on the substrate support, the one or more predefined features being positioned at predetermined locations on the substrate support; and A processor is configured to determine a true center of the calibration substrate and a center of the substrate support using the one or more images.

19. The system of claim 18, wherein the controller further comprises instructions that, when executed, cause the processor to compare a difference between the center of the substrate support and the true center of the calibration substrate to a predetermined threshold limit to determine whether an offset correction is required.

20. The system of claim 19, wherein the controller further comprises instructions that, when executed, cause the processor to adjust the placement of the substrate by the transfer robot based on the offset correction if it is determined that the offset correction is needed.

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