Method and apparatus for calibration of substrate processing chamber geometry via imaging

Abstract

In one embodiment, a calibration substrate is provided that generally includes a top surface that includes a plurality of first and second marking features configured to be detectable by an imaging device relative to a remainder of the top surface of a body.

Description

[Technical Field]

[0001]

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

[0002]

[0001] Multi-chamber semiconductor manufacturing systems, in which multiple processing chambers are integrated, are used to process substrates for manufacturing semiconductor devices. In multi-chamber manufacturing systems, substrates can be transferred from a substrate load lock chamber to a processing chamber using a transfer robot for processing. One of the challenges in handling and positioning a substrate is the need to position the center of the substrate with sufficient precision to enable accurate placement of the substrate on a substrate support within the processing chamber.

[0003]

[0002] One example of the importance of placement accuracy is that substrate supports (e.g., susceptors) for holding substrates in processing chambers typically include a pocket in which the substrate is placed. For a given substrate, the pocket on the susceptor into which the substrate fits typically has a diameter only slightly larger than that of the substrate. There is often very little clearance between the edge of the substrate and the edge of the susceptor pocket. Therefore, it is important to center the substrate in the pocket so that it does not contact the sidewalls of the susceptor pocket. If the substrate does contact the sidewalls of the pocket, local temperature variations occur, resulting in temperature gradients across the substrate. This can lead to non-uniform processing results.

[0004]

[0003] In many cases, the centering and positioning of a substrate on a susceptor is established by verifying that the center of the substrate coincides with the center of the rotating susceptor. Existing substrate center detection methods typically rely on image processing and detection of the edge of the substrate and / or detection of the gap between the edge of the substrate and the edge of the susceptor. As the substrate and susceptor are rotated on the pedestal, the edge of the substrate or gap is progressively imaged. The use of edge shadow and / or reflectance methods typically relies on a similar principle. A map matrix of edge position versus rotation angle is used as input to an algorithm. This algorithm determines the mathematical center of the substrate. Due to computational requirements, such approaches can require relatively high image processing power and resources and can be time-consuming. Furthermore, such approaches can have limited accuracy. For example, light from a light source used to capture substrate position can have a dispersion effect, distorting the image of the captured substrate edge. Movement of the photodetector or substrate can further introduce inaccuracies into the image. Such inaccurate position readings can therefore produce inaccurate results in determining the center and orientation of the substrate.

[0005]

[0004] Other attempts, including commercial off-the-shelf hardware, have used lasers to detect the edge of a substrate by reflectivity or dispersion. While these methods are somewhat successful at detecting the edge of transparent substrates, they raise significant regulatory and safety concerns and are expensive to implement. Furthermore, these systems are difficult to fully integrate into the substrate chamber or equipment, and therefore present significant challenges in fit and installation, making them at best a substitute for simple sensor arrays. These systems can also be very difficult to tune.

[0006]

[0005] Therefore, there is a need for improved methods, apparatus, and systems for calibrating and positioning a substrate in a processing chamber. Summary of the Invention

[0007]

[0006] Embodiments of the present disclosure provide methods, apparatus, and systems for calibrating the positioning and placement of a substrate in a processing chamber via imaging. In some embodiments, a method for analyzing the placement of a calibration substrate in a processing chamber is provided. The method includes placing the calibration substrate on a substrate support in the processing chamber using a transfer robot. The calibration substrate includes a plurality of marking features and at least one edge marking feature on an upper 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 processing chamber. The method continues by capturing one or more images of the calibration substrate and the substrate support using the imaging device. The one or more images show the plurality of marking features on the calibration substrate relative to one or more predefined features on the substrate support, with the one or more predefined features located at predetermined locations 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 another embodiment, a calibration substrate for use in a processing chamber is provided. The calibration substrate includes a circular body having a top surface and an outer periphery. 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 periphery. The plurality of first marking features and the second marking feature are configured to be detectable by an imaging device relative to a remainder of the top surface of the body.

[0009] In a further embodiment, a processing system for analyzing a calibration substrate in a processing chamber is provided. The processing system includes a processing chamber having a processing space and a substrate support disposed within the processing space. The system includes a calibration substrate disposed on the substrate support by a transfer robot, and an imaging device coupled to the processing 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, with the one or more predefined features disposed at predetermined locations on the substrate support. The controller further 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.

[0010]

[0009] So that the above-mentioned features of the present disclosure can be understood in detail, a more particular description of the present disclosure briefly summarized above can be made by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings illustrate only exemplary embodiments and therefore should not be considered to limit the scope of the present disclosure, which may also admit of other equally effective embodiments.

[0011]

[0010] However, it should be noted that the present disclosure may allow for other equally effective embodiments, and therefore the attached drawings illustrate only typical embodiments of the present disclosure and should not be considered as limiting the scope of the present disclosure. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic cross-sectional side view of a processing chamber according to certain embodiments of the present disclosure. [Figure 2A] 1 illustrates a top view of an exemplary calibration substrate, in accordance with certain embodiments of the present disclosure. [Figure 2B] 2B illustrates a top view of the calibration substrate of FIG. 2A positioned on a substrate support, according to certain embodiments of the present disclosure. [Figure 3] 2 is a flow diagram of a method for analyzing a calibration substrate placed in the processing chamber of FIG. 1 by a transfer robot, according to certain embodiments of the present disclosure. [Figure 4] 1 is a schematic cross-sectional side view of a processing chamber according to certain embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013]

[0016] For ease of understanding, where possible, identical reference numerals have been used to designate identical elements that are common to multiple figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further description.

[0014]

[0017] Reference will now be made in detail to the embodiments. Examples of embodiments are illustrated in the accompanying drawings, some, but not all, of which embodiments are shown in the drawings. Indeed, the concepts of the present disclosure may be embodied in many different forms and should not be construed as limited herein. Rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Wherever possible, like reference numbers are used to refer to like components or parts.

[0015]

[0018] The present disclosure relates generally to substrate processing systems, and more particularly to methods, apparatus, and systems that facilitate positioning, setup, and monitoring of a substrate within a processing chamber. In semiconductor manufacturing, prior to processing a substrate within a processing chamber, the setup process of the processing chamber generally includes analyzing the placement of the substrate relative to a substrate support, thereby ensuring that the substrate is properly and optimally positioned by a transfer robot for processing. Proper positioning of the substrate by the transfer robot includes confirming 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 processing chamber. As described above, analyzing the placement and position of the substrate includes determining the center of the positioned substrate from the captured images for comparison with the center of the substrate support. If the positioning of the center of the substrate obtained from the captured images is determined to be 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.

[0016]

[0019] Embodiments disclosed herein include a calibration substrate for use during process chamber setup. The calibration substrate can help ensure proper substrate placement by a transfer robot by facilitating detection and correction of the substrate's center during process chamber calibration operations prior to processing. The calibration substrate includes a plurality of marking features, each 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 viewed and analyzed relative to one or more defined features on a substrate support and / or preheat ring in the process chamber that also have known sizes and positions, data about the calibration substrate and substrate support can be obtained to determine, among other things, the location of the center of the positioned calibration substrate, the location of the center of the substrate support holding the calibration substrate, the rotation angle of the calibration substrate and substrate support, a reference measurement for direct scaling of the substrate level in the captured image, any offset between the calibration substrate and the substrate support that requires correction, and any offsets between corrections.

[0017]

[0020] Typically, a processing system has a centralized transfer chamber mounted on a monolithic platform. The transfer chamber is the center of activity for movement of substrates being processed within the system. One or more processing 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.

[0018]

[0021] 1 is a schematic cross-sectional side view of a processing chamber 100 according to certain embodiments. The processing chamber 100 is a deposition chamber. In one embodiment, which can be combined with other embodiments, the processing chamber 100 is an epitaxial deposition chamber. The processing chamber 100 is utilized to grow an epitaxial film on a substrate 108. The processing chamber 100 generates a cross-flow of precursors across the top surface of the substrate 108.

[0019]

[0022] The processing chamber 100 may include, among other components, an array of radiant heat lamps 102 for heating a substrate support 106 (which may be, for example, a susceptor) disposed within the processing 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 disk-shaped substrate support 106 as shown, or may be a ring-shaped substrate support 107 without a central opening (which would support the substrate from its edge to facilitate exposure of the substrate to the thermal radiation of the lamps 102).

[0020]

[0023] As shown, a controller 120 and a camera 166 are in communication with the processing chamber 100. The controller 120 may be used to control processes and methods, such as the operation of the methods described herein. The camera 166 may be used to capture images of the substrate 108 and / or components (e.g., calibration substrates) inside the processing chamber 100 for use with processes and methods, such as the operation of the method 300 described herein. The controller 120, camera 166, and processing chamber 100 may be part of a substrate processing system.

[0021]

[0024] The substrate support 106 is positioned within the processing 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 the interior region of the processing chamber 100. A substrate 108 (not to scale) may be loaded into the processing chamber 100 via a loading port 103 and placed on the substrate support 106.

[0022]

[0025] The substrate support 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, which allows lift pins 105, which pass through holes in the substrate support 106 and through the central shaft 132, to contact the lower dome 114 and lift the substrate 108 off the substrate support 106. A robot (not shown) can then enter the processing chamber 100 to engage the substrate 108 and remove it from the processing chamber 100 via the loading port 103. The substrate support 106 can then be moved upward to the processing position, and the substrate 108 can be placed on the upper surface 110 of the substrate support 106 with its device side 116 facing up.

[0023]

[0026] While in the processing position, the substrate support 106 divides the interior space of the processing chamber 100 into a process gas region 156 above the substrate and a purge gas region 158 below the substrate support 106. The substrate support 106 is rotated by a central shaft 132 during processing to minimize the effects of spatial biases in heat and process gas flow within the processing chamber 100, thus promoting uniform processing of the substrate 108. The substrate support 106 is supported by the central shaft 132, which moves the substrate 108 up and down in a direction 134 during loading and unloading of the substrate 108, and optionally during processing of the substrate 108. To absorb radiant energy from the lamps 102 and transfer the radiant energy to the substrate 108, The substrate support 106 may be formed from silicon carbide or silicon carbide coated graphite.

[0024]

[0027] Generally, 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. "Optical transparent," as used herein, generally means that radiation is transmitted through it, but not necessarily 100%. As described in more detail below with respect to FIG. 1, the thickness and curvature of upper dome 128 can be configured in accordance with the present invention to achieve a flatter profile for uniform flow within the processing chamber.

[0025]

[0028] One or more lamps, such as an array of lamps 102, may be arranged in a particular configuration around the central shaft 132 near and below the lower dome 114 to separately control the temperature at various regions of the substrate 108 as process gases pass through, thereby facilitating the deposition of material on 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, among other materials.

[0026]

[0029] The lamps 102 may include bulbs 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 coupled to a power distribution board (not shown), through which power is supplied to each lamp 102. The lamps 102 are positioned within a lamp head 145, which may be cooled during or after processing, for example, by a cooling fluid introduced into channels 149 located between the lamps 102. Due in part to the proximity of the lamp head 145 to the lower dome 114, the lamp head 145 cools the lower dome 114 conductively and radiatively. The lamp head 145 may also cool the lamp walls and the walls of a reflector (not shown) surrounding the lamp. Alternatively, the lower dome 114 may be cooled by a convective approach. Depending on the application, the lamp head 145 may or may not contact the lower dome 114.

[0027]

[0030] Optionally, a circular shield 167 may be positioned around the substrate support 106 and surrounded by the liner assembly 163. The shield 167 prevents or minimizes thermal / light noise leakage from the lamps 102 to the device side 116 of the substrate 108, as well as providing a preheat zone for the process gases. The shield 167 may be made from CVD SiC, SiC-coated sintered graphite, grown SiC, opaque quartz, coated quartz, or any similarly suitable material that is resistant to chemical decomposition by the process and purge gases.

[0028]

[0031] 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 shields the processing space (i.e., the process gas region 156 and the purge gas region 158) from the metal walls of the processing chamber 100, which can react with precursors and cause contamination within the processing space. Although the liner assembly 163 is shown as a single body, the liner assembly 163 can include one or more liners of various configurations.

[0029]

[0032] As a result of heating the substrate 108 by the substrate support 106, it is possible to implement the use of an optical pyrometer 118 for temperature / measurement control on the substrate support 106. 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 top surface 110 of the substrate in this manner is emissivity independent. As a result, the optical pyrometer 118 can only sense radiation from the hot substrate 108 that is transmitted through the substrate support 106, where background radiation reaching the optical pyrometer 118 directly from the lamps 102 is minimal.

[0030]

[0033] Optionally, a reflector 122 may be positioned outside the upper dome 128 to reflect infrared radiation emitted from the substrate 108 back to the substrate 108. The reflector 122 may be secured to the upper dome 128 using a clamp ring 130. The reflector 122 may be made of a metal such as aluminum or stainless steel. Coating the reflector region with a highly reflective coating such as gold may improve reflective efficiency. 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 part or all of the surface of the reflector 122 to cool it.

[0031]

[0034] Process gas supplied from a process gas source 172 is introduced into the process gas region 156 through process gas inlets 174 formed in a sidewall of the base ring 136. The process gas inlets 174 are configured to direct the process gas generally radially inward. During a 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 inlets 174, allowing the process gas to flow upward along flow paths 173 across the upper surface of the substrate 108 in a laminar manner. The process gas is exhausted from the process gas region 156 (along flow paths 175) through a gas outlet 178 located on the opposite side of the processing chamber 100 from the process gas inlet 174. Removal of the process gas through the gas outlet 178 can be facilitated by a vacuum pump 180 connected to the gas outlet 178. Because the process gas inlet 174 and gas outlet 178 are aligned with one another and positioned at approximately the same height, it is believed that this parallel arrangement, when combined with the flatter upper dome 128 (discussed in more detail below), allows for a generally planar and uniform gas flow across the substrate 108. Additionally, rotation of the substrate 108 via the substrate support 106 can provide radial uniformity.

[0032]

[0035] Controller 120 includes a central processing unit (CPU), memory containing instructions, and support circuitry for the CPU. Controller 120 controls various items directly or through other computers and / or controllers. In one or more embodiments, controller 120 is communicatively coupled to a dedicated controller, with controller 120 functioning as a central controller.

[0033]

[0036] The controller 120 is any form of general-purpose computer processor used in industrial settings to control various substrate processing chambers and equipment, as well as sub-processors located thereon or therein. The memory, or non-transitory computer-readable medium, is one or more of readily available memory (e.g., 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 circuitry of the controller 120 is coupled to the CPU (processor) to support the CPU. The support circuits include cache, power supplies, clock circuits, input / output circuits and subsystems, etc. Operational 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 gases) and operations are stored in memory as software routines that are executed or called to transform the controller 120 into a special-purpose controller for controlling the operation of the various chambers / modules described herein. The controller 120 is configured to perform any of the methods described herein. The instructions stored in the memory, when executed, cause one or more of the operations of the method 300 (described below) to be performed.

[0034]

[0037] The various operations described herein (e.g., the operations of method 300) may be performed automatically using controller 120, or may be performed automatically or manually with certain operations performed by a user.

[0035]

[0038] The controller 120 is configured to control the camera and rotational positioning within the processing chamber 100 by providing outputs for controls for the heat sources 141, 143, gas flows, and motion assembly 121. Such 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.

[0036]

[0039] The controller 120 is configured to adjust the output for control based on sensor readings, a system model, and stored readings and calculations. The controller 120 includes embedded software and one or more correction algorithms for calibrating measurements. The controller 120 may include one or more machine learning and / or artificial intelligence algorithms that estimate optimized parameters for the deposition, purge, and / or cleaning operations. The one or more machine learning and / or artificial intelligence algorithms may use, for example, regression models (e.g., linear regression models) or clustering techniques to estimate the optimized parameters. The algorithms may be unsupervised or supervised.

[0037]

[0040] Substrates (including calibration substrates) can be transferred in and out of the interior space of the processing chamber 100 through a transfer door 137 (e.g., a slit valve). When the transfer door 137 is open, the transfer robot (on which the substrate is disposed) can extend through the transfer door 137 into the interior space, allowing the lift pins 105 to lift the substrate from the transfer robot and place it on the substrate support 106 for processing. After processing, the lift pins 105 can lift the substrate from the substrate support 106 and place the substrate back onto the transfer robot, which can be retracted through the open transfer door 137 to remove the substrate from the processing chamber 100.

[0038]

[0041] As described above, systems and methods are provided herein for calibrating the placement and positioning of a substrate by a transfer robot within a processing chamber using image processing, using a plurality of marking features disposed on a calibration substrate. Processing images of the substrate support and the calibration substrate thereon can also be used to assist in detecting the rotation, angle, and gap between the edge of the calibration substrate and the substrate support. Thus, a visualization system including an imaging device (e.g., camera 166 shown in FIG. 1 ) either inside or outside a processing chamber (e.g., processing chamber 100) and having a field of view through an aperture in the chamber can be used to capture images of a calibration substrate disposed within processing chamber 100.

[0039]

[0042] As shown in FIG. 1 , the processing chamber 100 may include a camera 166 for viewing the substrate 108, the substrate support 106, and / or a preheat ring (not shown) coupled to the substrate support 106 within the processing chamber 100. The camera 166 may be positioned above the top of the processing chamber 100, and a collection device for the camera (e.g., a light pipe) may be disposed through the top of the processing chamber 100 into the processing gas region 156. Alternatively, the camera 166 may be positioned inside the processing chamber 100. For example, the camera 166 may be disposed in an opening 186 in the upper dome 128 between the upper dome 128 and the reflector 122. The camera 166 or a collection device for the camera may be disposed through an inlet connecting the conduit 126 to the processing chamber 100, or alternatively, the camera 166 may be coupled to the chamber using a chassis. The camera 166 may be operable at vacuum or atmospheric pressure. A camera 166 may be present in the processing chamber 100 to capture images of the substrate 108, the edge ring, the mask, and / or the substrate support 106. The position of the camera 166 relative to the upper dome 128 and the substrate support 106, as well as the optical properties of the camera 166, may be determined to ensure a field of view that includes an area of ​​interest on the substrate support 106.

[0040]

[0043] The camera 166 may be electrically connected to the controller 120, which controls the operation of the camera 166 (e.g., on / off, focusing, imaging, etc.). It should be noted that the camera 166 is merely one example of a device that can be used to capture the calibration substrate and substrate support, and any other type of imaging device can be used as a position detection device. In some embodiments, more than one camera can be used to capture images of the substrate support 106. In some embodiments, the camera 166 is an imaging device that can include a high-efficiency, low-voltage complementary metal oxide semiconductor (CMOS) sensor and can therefore function as a single-chip video camera. The CMOS sensor can be of the VGA type. The camera 166 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 the camera 166. It will be apparent to those skilled in the art that various lenses (e.g., a telephoto lens or a rotating prism lens) can be used for various applications. It will be further understood that other types of cameras or optical sensors may be utilized, including, but not limited to, SVGA, XGA, MEGA pixel type cameras, or other imaging devices. If desired, multiple imaging devices with different resolutions may be used in combination with various lens types and focal lengths. The camera or sensor may be of the static (still image) or dynamic (video) type and may be of the charged coupled device (CCD) type. Additionally, the camera 166 may be used to output a video signal in any standard TV format.

[0041]

[0044] FIG. 2A illustrates a top view of an exemplary calibration substrate 200 that can be used in accordance with the methods and operations disclosed herein, in accordance with certain embodiments of the present disclosure. The calibration substrate 200 can be handled by a transfer robot and placed on a substrate support 106 in a processing chamber 100. The calibration substrate 200 can be formed similarly to the devices (e.g., wafers or substrates) that are handled by the transfer robot and processed by the processing 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 with an alignment point on the transfer robot. The alignment point can be a corresponding hole or depression on the transfer robot that mates with the notch aligner in the calibration substrate 200. The notch aligner can help provide consistent handling of the calibration substrate 200 by the transfer robot.

[0042]

[0045] 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 assist in calibrating the placement of the substrate by a transfer robot. In certain embodiments, the plurality of marking features 204 can help determine the location of the center of the calibration substrate 200 placed by the transfer robot, as well as the location of the center of the substrate support holding the calibration substrate 200. The locations of the center of the calibration substrate 200 and the center of the substrate support 106 can then be used to determine a calculated offset between the calibration substrate 200 and the substrate support 106 that needs to be corrected. In certain embodiments, the calibration substrate 200 can further include at least one edge marking feature 206 formed along the periphery of the calibration substrate 200. The at least one edge marking feature 206 can assist in determining a corresponding rotation angle and rotation angle correlation when analyzing captured images of the calibration substrate 200 inside the processing chamber 100.

[0043]

[0046] In some embodiments that can be combined with other embodiments herein, the plurality of marking features 204 can be disposed or formed on the top surface 202 of the substrate support 200 and can be any type of designation that can be detected by the camera 166 for image analysis. In some embodiments that can be combined with other embodiments described herein, the plurality of marking features 204 can be surface features formed on the top surface 202 of the calibration substrate 200. In other embodiments, the plurality of marking features 204 can be surface features etched into the top surface 202 of the calibration substrate 200. In certain embodiments, the designation of the plurality of marking features 204 can include any numbers, letters, symbols, shapes, or patterns, including, but not limited to, bar codes, numeric codes, alphanumeric codes, QR codes, custom shapes, patterns of shapes, patterns of symbols, series of letters, special characters, and the like. In the embodiment shown in FIG. 2A, the plurality of marking features 204 are formed as circles, and at least one edge marking feature 206 is formed as a curved arc that follows a portion of the edge 207 of the calibration substrate 200.

[0044]

[0047] To use the plurality of marking features 204, including the at least one edge marking feature 206, as relative reference points in an imaged image of the calibration substrate 200, the plurality of marking features 204 and the at least one edge marking feature 206 may be formed on the top surface 202 of the calibration substrate 200 with predetermined dimensions and locations. By forming the plurality of marking features 204 of known sizes, the plurality of marking features 204 may be used to provide reference measurements for direct scaling at substrate level in an imaged image of the calibration substrate 200.

[0045]

[0048] 2B illustrates a top view of the calibration substrate of FIG. 2A positioned on a substrate support within the processing chamber of FIG. 1 , according to certain embodiments. Once the calibration substrate 200 is positioned within the processing chamber 100, images of the plurality of marking features 204 and at least one edge marking feature 206 on the calibration substrate 200 may 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 within the processing chamber 100. Once an image of the calibration substrate 200 positioned on the substrate support 106 within the processing chamber is acquired, the plurality of marking features 204 within the image of the calibration substrate 200 may be detected and analyzed. Image analysis performed on such images allows the positions of the plurality of marking features 204 to be determined as coordinate points on the top surface 202 of the calibration substrate 200 relative to one or more predetermined features 208 on the substrate support 106 and / or preheat ring within the processing chamber 100. The positions of the multiple marking features 204 can then be used to determine the true center of the calibration substrate 200. Thus, being able to use multiple marking features 204 detected in images acquired by the camera 166 may advantageously allow for more efficient and accurate determination of the true center of the calibration substrate 200 via imaging.

[0046]

[0049] Although some examples are described herein as applying a plurality of marking features 204 to a calibration substrate 200, embodiments of the disclosure described herein with respect to forming marking features 204 on a calibration substrate 200 may be equally applicable to applying one or more predefined features 208 to a substrate support 106 and / or a preheat ring in a processing chamber 100. Thus, in some embodiments, the one or more predefined features 208 may be formed on the substrate support 106 and / or a preheat ring, similar to the formation of a plurality of marking features 204 formed on a calibration substrate 200 described herein. In other embodiments, the one or more predefined features 208 on the substrate support 106 holding the calibration substrate 200 and / or the preheat ring may be digitally implemented on an image of the substrate support 106 and / or the preheat ring captured by the camera 166.

[0047]

[0050] As shown in FIG. 2B , one or more predetermined features 208 may be formed on the top surface of the substrate support 106 and / or preheat ring. The one or more predetermined features 208 may be formed on a portion of the substrate support 106 and / or preheat ring at a predetermined location within the field of view of the camera 166. The one or more predetermined features 208 captured in the 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 predetermined features 208 on the substrate support 106 and / or preheat ring within the processing 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 position of the calibration substrate 200 thereon. In certain embodiments in which the calibration substrate 200 is accommodated within a pocket of the substrate support 106, the center 214 of the substrate support 106 may correspond to the center of the pocket of the substrate support 106.

[0048]

[0051] Once the calibration substrate 200 is placed on the substrate support 106, the coordinates of each of the plurality of marking features 204 can be determined using the same coordinate system 212, using one or more predetermined features 208 on the substrate support 106 and / or preheat ring as relative reference points. To assist in determining the location of the center of the calibration substrate 200 mounted on the substrate support 106, the plurality of marking features 204 on the calibration substrate 200 includes a sufficient number of marking features 204 to determine a mathematical representation of at least three chords 216 each extending across a diameter of the calibration substrate 200 (e.g., at least six marking features 204 representing six coordinate points on the calibration substrate 200). The three chords 216 can then be used to determine 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 with the coordinates of the center 214 of the substrate support 106 that have already been determined to analyze whether the placement of the calibration substrate 200 on the substrate support 106 by the transfer robot is appropriate.

[0049]

[0052] Advantageously, in contrast to rotated images required when relying on gap detection, the plurality of marking features 204 on the calibration substrate 200 and the one or more predetermined features 208 on the substrate support 106 and / or preheat ring allow 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 still images of the calibration substrate 200 captured by the camera 166. This reduces the need for tedious image processing, which may also require additional corresponding data regarding the rotation angle and correlation of each rotated image, without the need to analyze a series of images of the calibration substrate 200 being rotated by the substrate support 106.

[0050]

[0053] In certain embodiments, the at least one edge marking feature 206 includes an arc design formed along a portion of the edge 207 of the calibration substrate 200. The arc design along the edge 207 of the calibration substrate 200 can be used to determine, via image analysis, the rotation angles of the calibration substrate 200 and the substrate support 106, as well as the correlation between the rotation angles of the calibration substrate 200 and the substrate support 106 and the home angle. Accordingly, an image of the at least one edge marking feature 206 on the calibration substrate 200 can be used to help monitor the positioning of the calibration substrate 200 as the calibration substrate 200 is rotated to confirm a calculated offset between the calibration substrate 200 and the substrate support 106. For example, the at least one edge marking feature 206 on the calibration substrate 200 can be used to monitor the gap offset via imaging as the calibration substrate is rotated.

[0051]

[0054] 3 shows a flow diagram of a method 300 for determining the offset of a calibration substrate placed on a substrate support in a processing 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 a substrate processing system. The method 300 is used to determine and compare the coordinates of the true center 218 of the calibration substrate 200 and the coordinates of the center 214 of the substrate support 106.

[0052]

[0055] The method 300 begins at operation 302, in which the calibration substrate 200 is placed by a transfer robot onto a substrate support within a processing chamber (e.g., the substrate support 106 within the processing chamber 100). When the calibration substrate 200 is placed on the substrate support 106, at least a portion of the plurality of marking features 204 on the calibration substrate 200 and at least a portion of the one or more predefined features 208 on the substrate support 106 may be within the field of view of the camera 166.

[0053]

[0056] In 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 positions of the plurality of marking features 204 on the calibration substrate 200 relative to the substrate support 106. In some embodiments, all of the marking 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 marking features 204 may be formed such that only some of the plurality of marking 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 specific portions of the calibration substrate 200 and capture any remaining marking features 204 of the plurality of marking features 204 formed on the calibration substrate 200. Alternatively, the calibration substrate 200 can be rotated by the substrate support 106 to move a specific portion of the calibration substrate 200 having the remaining features of the plurality of marking features 204 within the field of view of the camera 166 for imaging.

[0054]

[0057] In certain embodiments, the image of the substrate support 106 includes one or more predefined features 208 formed on the top surface of the substrate support 106 at known locations. Alternatively, the one or more predefined features 208 may be digitally implemented for image analysis after the one or more images are acquired by the camera 166. In both cases, the one or more images may include an indication of the positions of the multiple marking features 204 relative to the one or more predefined features 208 on the substrate support 106.

[0055]

[0058] In operation 306, 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 one or more predefined features 208 on the substrate support 106. The one or more predefined features 208 on the substrate support 106 may be used to define a coordinate system, where the known locations of the one or more predefined features 208 are used as reference points for defining all other positioning coordinates. In some embodiments, a standardized center finder software algorithm (e.g., a best-fit type 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 predefined features 208 on the substrate support 106.

[0056]

[0059] In operation 308, coordinates of the plurality of marking features 204 shown 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 described above, the one or more predefined features 208 may be used as reference points to define a coordinate system. The same coordinate system may extend across the top surface of the substrate support 106 such that the coordinate system may 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 marking features 204 on the same coordinate system may 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 marking features 204 relative to the predefined features 208 shown in the one or more images captured by the camera 166 and detected by image analysis.

[0057]

[0060] 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. As described above in operation 306, the coordinates of the true center 218 of the calibration substrate 200 can be determined based on the acquired coordinates of the plurality of marking features 204 using a standardized center finder software algorithm, the same or similar to that used to determine the coordinates of the center 214 of the substrate support 106. For example, as shown in FIG. 1B , the coordinates of the plurality of marking features 204 on the calibration substrate 200 can be used to create a mathematical representation of at least three chords extending across the diameter of the calibration substrate 200. Normals to the chords can then be ascertained to determine the intersection points of the chords, from which the coordinates of the true center 218 of the calibration substrate 200 can be calculated. Thus, the plurality of marking features 204 on the calibration substrate 200 can be analyzed to determine the true center 217 of the calibration substrate 200.

[0058]

[0061] In operation 312, the coordinates of the calculated true center 218 from operation 310 may be compared with the coordinates of the center 214 of the substrate support 106 to determine whether the coordinates of the two centers are within predetermined threshold limits of each other. If the calculated coordinates of the center of the calibration substrate 200 and the center of the substrate support 106 are within the threshold limits, then placement of the calibration substrate 200 on the substrate support 106 may be deemed appropriate and / or at least sufficient for processing of the substrate to be performed in the processing chamber 100. In operation 314, if the coordinates of the center of the calibration substrate 200 and the center of the substrate support 106 are outside the threshold limits, an offset correction is determined based on this difference.

[0059]

[0062] In operation 316, if it is determined that an offset correction is necessary, the placement of the substrates (including the calibration substrate 200 of operation 302) by the transfer robot may be adjusted based on the offset correction determined by the controller 120 (to center the placement of the substrate on the substrate support 106 by the transfer robot). For example, the offset correction may be sent to the transfer robot, which may adjust its programmed substrate handling and placement position by an amount equal to the offset correction.

[0060]

[0063] If adjustments to the transfer robot are made using the calculated offset corrections, operations 302-310 can be repeated to verify that the adjustments made using the calculated offset corrections are sufficient so that the calculated true center 218 of the calibration substrate 200 positioned by the transfer robot is within a threshold limit of the center 214 of the substrate support 106. Once the placement of the calibration substrate 200 by the transfer robot is sufficiently calibrated, the calibration substrate 200 can be stored in a load lock chamber of the processing system. The method 300 for calibrating the placement of substrates by the transfer robot can be performed periodically for maintenance and quality control. In some embodiments, the calibration process can be performed more frequently depending on the extent of use of the processing chamber 100 and whether changes are made to the processing parameters of the processing chamber 100 or the substrates being processed by the transfer robot for processing.

[0061]

[0064] 4 is a schematic top plan view of a processing system 400 according to one implementation. The processing system 400 includes one or more substrate load lock chambers 422, a vacuum-tight processing platform 404, a factory interface 402, and a controller 444. The substrate load lock chambers 422 may be a load lock chamber. In one embodiment, the processing system 400 may be a CENTURA® Integrated Processing System commercially available from Applied Materials, Inc., Santa Clara, California. It is contemplated that other processing systems (including those from other manufacturers) may be adapted to benefit from the present disclosure.

[0062]

[0065] The platform 404 includes multiple 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 processing chamber 100. A factory interface 402 is connected to the transfer chamber 436 by two substrate load lock chambers 422.

[0063]

[0066] In one embodiment, the factory interface 402 includes at least one docking station 408 and at least one factory interface robot 414 to facilitate substrate transfer. The docking station 408 is configured to receive one or more front-opening unified pods (FOUPs). Two FOUPS 406A, 406B are shown in the implementation of FIG. 4. The factory interface robot 414, having a blade 416 located at one end of the robot 414, is configured to transfer one or more substrates from the FOUPs 406A, 406B through substrate load lock chambers 422 to the processing platform 404 for processing. In certain embodiments, the transferred substrates may be stored in the substrate load lock chambers 422. In certain embodiments, the calibration substrate 200 may also be stored in one of the substrate load lock chambers 422.

[0064]

[0067] Each of the substrate load lock chambers 422 has a first port that connects to the factory interface 402 and a second port that connects to the transfer chamber 436. The substrate load lock chambers 422 are coupled to a pressure control system (not shown) that pumps down and vents the substrate load lock chambers 422 to facilitate passage of substrates between the vacuum environment of the transfer chamber 436 and the substantially ambient (e.g., atmospheric) environment of the factory interface 402.

[0065]

[0068] A transfer robot 430 is disposed within 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.

[0066]

[0069] 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 processing chambers 410, 412, 432, 428, 420 of the system 400, or alternatively, by controlling a computer (or controller) associated with the processing chambers 410, 412, 432, 428, 420 and the system 400. In operation, the controller 444 enables data collection and feedback from each chamber and the controller 444 to optimize the performance of the system 400.

[0067]

[0070] The controller 444 is used to control the operation of processes and methods, such as those described herein (e.g., the operation of method 300, described below). The controller 444 includes a central processing unit (CPU) 438, a memory 440 containing instructions, and support circuits 442 for the CPU. The controller 444 controls various items directly or via other computers and / or controllers. In one or more embodiments, the controller 444 is communicatively coupled to a dedicated controller, and the controller 444 functions as a central controller.

[0068]

[0071] The controller 444 is any form of general-purpose computer processor used in industrial settings to control various substrate processing chambers and equipment, as well as sub-processors located thereon or therein. The memory 440, or non-transitory computer-readable medium, is one or more of readily available memory (e.g., 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 digital storage, local or remote. The support circuits 442 of the controller 444 are coupled to the CPU 438 (processor) for supporting the CPU 438. The support circuits 442 may include cache, power supplies, clock circuits, input / output circuits, , and subsystems, etc. Operating parameters (e.g., 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 one or more software routines that are executed or invoked to transform controller 444 into a special-purpose controller and control the operation of the various systems / chambers / units / modules described herein. When executed by CPU 438, one or more software routines transform CPU 438 into a special-purpose computer. The software routines may also be stored and / or executed by a second controller (not shown) located remotely from system 400.

[0069]

[0072] The controller 444 is configured to perform any of the operations described herein. The instructions stored in the memory, when executed, cause one or more of the operations (described below) of the method 300 to be performed. The various operations described herein may be performed automatically using the controller 444, or certain operations may be performed automatically and / or manually by a user.

[0070]

[0073] The controller 444 is configured to adjust the output to the control unit of the system 400 based on the sensor readings, the system model, and the stored readings and calculations. By way of example, one or more operational parameters can be measured by one or more sensors positioned along the system 400. The controller 444 includes embedded software and correction algorithms for calibrating the measurements. The controller 444 can include one or more machine learning and / or artificial intelligence algorithms that estimate optimized parameters for one or more deposition operations, cleaning operations, etching operations, and / or one or more atomic radical processing operations. The one or more machine learning and / or artificial intelligence algorithms can use, for example, regression models (e.g., linear regression models) or clustering techniques to estimate the optimized parameters. The algorithms can be unsupervised or supervised. The one or more machine learning and / or artificial intelligence algorithms can optimize the operational parameters used in connection with the operations described herein.

[0071]

[0074] Although embodiments of the present disclosure have been described above with reference to particular embodiments, numerous specific details have been set forth to provide a more thorough understanding of the present invention. However, those skilled in the art will recognize that various modifications and changes may be made thereto without departing from the broad spirit and scope of the present invention. Correspondingly, the foregoing specification and drawings are to be regarded as illustrative rather than restrictive.

[0072]

[0075] While the above 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 determined by the claims that follow.

Claims

1. 1. A method for analyzing a calibration substrate in a processing chamber, comprising: using a transfer robot to place a calibration substrate on a substrate support disposed within a processing chamber, the calibration substrate including 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 configured to be detectable by an imaging device coupled to the processing chamber, the at least one edge marking feature being disposed along a periphery 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 features on the calibration substrate relative to one or more predefined features on the substrate support, the one or more predefined features being located at predetermined locations on the substrate support; determining a center of the substrate support and a true center of the calibration substrate; A method comprising:

2. 2. The method of claim 1, further comprising comparing whether a difference between the center of the substrate support being checked and the true center of the calibration substrate is within a predetermined threshold limit to determine whether an offset correction is required.

3. The method of claim 2 , further comprising, if the offset correction is determined to be necessary, adjusting the transfer robot based on the offset correction.

4. 2. The method of claim 1, wherein analyzing the one or more images to determine the center of the substrate support comprises determining the center of the substrate support from the one or more images using the predetermined positions of the one or more predetermined features.

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

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

7. Determining the true center of the calibration substrate 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; using said intersection point to determine the true center of said calibration substrate; The method of claim 6, comprising:

8. 2. The method of claim 1 , wherein capturing one or more images of the calibration substrate and the substrate support comprises capturing one or more images of the one or more predetermined features formed on a top surface of the substrate support.

9. The method of claim 1 , further comprising digitally implementing the one or more predetermined features on the substrate support in the one or more images.

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

11. 3. The method of claim 2, further comprising verifying the offset correction when it is determined that the offset correction is necessary by monitoring a gap offset via imaging using the at least one edge marking feature as the calibration substrate rotates.

12. 1. A calibration substrate for use in a processing chamber, comprising: a circular body having an upper surface and an outer periphery; 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 periphery; Equipped with a calibration substrate configured such that the plurality of first marking features and the second marking feature are detectable by an imaging device relative to the remainder of the top surface of the body;

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

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

15. 13. 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 or etched into the top surface of the body.

17. 13. The calibration substrate of claim 12, wherein the plurality of first marking features comprises a designation, shape, or pattern, including, but not limited to, a custom shape, a pattern of shapes, a symbol, and a special character.

18. 1. A processing system for analyzing a calibration substrate in a processing chamber, comprising: a processing chamber having a processing space; a substrate support disposed within the processing space and configured to receive a substrate; a calibration substrate placed on the substrate support by a transfer robot; an imaging device coupled to the processing chamber and connected to a controller, the controller including 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 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 located at predetermined locations on the substrate support; and a processor for determining a true center of the calibration substrate and a center of the substrate support using the one or more images; A processing system comprising:

19. 20. 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 with a predetermined threshold limit to determine whether an offset correction is required.

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

Images