Detection and adjustment of substrate position

Abstract

To provide systems and methods for positioning a wafer in relation to a datum structure such as an edge ring or chuck.SOLUTION: A system comprises a camera arrangement 200 of cameras 1, 2 including at least two cameras, each of the at least two cameras including fields 200', 200" of view when positioned in the camera arrangement, each field of view including a peripheral edge 204 of a wafer 206 and a peripheral edge 202 of a datum structure 210. A processor receives positional data from each of the at least two cameras and determines, in relation to each field of view, a gap size 208 between the respective peripheral edges of the wafer and the datum location included in the respective fields of view. A controller adjusts a position of the wafer relative to the datum structure, on the basis of the determined respective gap sizes.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] Claim of Priority This application claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 802,932, entitled "Wafer Location Detection and Adjustment" by Martin et al., filed on February 8, 2019, the entire content of which is incorporated herein by reference.

[0002] The present disclosure generally relates to detecting and adjusting the position of a substrate (e.g., a wafer) using camera images on a process tool in semiconductor manufacturing. In some examples, systems and methods are provided for positioning a substrate relative to a datum structure such as an edge ring or a chuck. Background Art

[0003] The description of the background provided herein is for the purpose of generally presenting the context of the present disclosure. To the extent described in this Background section, the research by the currently named inventors, as well as aspects of the description that may not otherwise be considered prior art as of the filing date of the present application, are not admitted to be prior art against the present disclosure, either expressly or impliedly.

[0004] One approach for centering a wafer on an edge ring or an electrostatic chuck (ESC) relies on obtaining blanket etch rate and backside particle data with a wafer placed at a "best guess" wafer center position. The blanket etch rate is obtained on the wafer at this position, after which post-etch metrology is performed on the blanket wafer to determine their deviations from the center. In backside particle testing, the backside particle imprint of a pre-coat on the ESC is used to determine the wafer offset relative to the ESC. This information can be used to adjust the calibration of a vacuum transfer module (VTM) robot to achieve wafer centering. This process is expensive and cumbersome, at least because blanket wafers are costly. [Overview of the project]

[0005] In some examples, systems are provided for positioning a wafer relative to a datum structure. An exemplary system comprises a camera configuration including at least two cameras, each of which, when positioned in the camera configuration, includes a field of view, each field of view including the peripheral edge of the wafer and the peripheral edge of the datum structure; a processor that receives position data from each of the at least two cameras and, in relation to each field of view, determines the gap size between the respective peripheral edges of the wafer and datum positions included in each field of view; and a controller that adjusts the position of the wafer relative to the datum structure based on the respective determined gap sizes.

[0006] In some examples, the datum location includes the edge ring. In some examples, the datum location includes the chuck.

[0007] In some examples, the camera configuration is mounted on the wall of the wafer processing chamber.

[0008] In some examples, the camera configuration includes a third camera, which provides the processor with positional data related to each of its third fields of view.

[0009] In some examples, each determined gap size is compared to each predetermined gap size, and each predetermined gap size is associated with the center position of the wafer or a desired position relative to the datum structure.

[0010] In some examples, the controller includes a robotic arm of a vacuum transfer module (VTM).

[0011] In some cases, the processor identifies the center of the wafer based on the determined gap size.

[0012] In some examples, a system for positioning a wafer relative to a datum structure comprises a camera configuration including one or more cameras, each of which, when positioned in the camera configuration, includes a field of view, each field of view including the peripheral edge of the wafer and the peripheral edge of the datum structure; a processor that receives position data from one or each camera and, in relation to each field of view, determines the gap size between the respective peripheral edges of the wafer and datum positions included in each field of view; and a controller that adjusts the position of the wafer relative to the datum structure based on the respective determined gap sizes.

[0013] In some examples, one or more cameras include a single movable camera.

[0014] In some examples, a single movable camera is mounted on a robotic arm.

[0015] In some examples, the robotic arm is mounted on a vacuum transfer module (VTM).

[0016] In some examples, the camera configuration is mounted on the wall of the wafer processing chamber. [Brief explanation of the drawing]

[0017] The attached drawings illustrate several embodiments, but these are illustrative examples and not limitations.

[0018] [Figure 1] Figure 1 is a schematic diagram of a reaction chamber in which several examples of the methods of this disclosure may be used.

[0019] [Figure 2] Figure 2 illustrates several examples of camera configurations. [Figure 3] Figure 3 illustrates several camera configurations.

[0020] [Figure 4] FIG. 4 is a diagram illustrating a camera image according to some examples. [Figure 5] FIG. 5 is a diagram illustrating a camera image according to some examples. [Figure 6] FIG. 6 is a diagram illustrating a camera image according to some examples. [Figure 7] FIG. 7 is a diagram illustrating a camera image according to some examples. [Figure 8] FIG. 8 is a diagram illustrating a camera image according to some examples.

[0021] [Figure 9] FIG. 9 is a diagram illustrating a camera configuration according to an exemplary embodiment.

[0022] [Figure 10] FIG. 10 is a scatter plot according to one example.

[0023] [Figure 11] FIG. 11 is a diagram illustrating operations in a method of centering a wafer according to one example.

[0024] [Figure 12] FIG. 12 is a diagram illustrating a single camera configuration according to one example. DESCRIPTION OF EMBODIMENTS

[0025] The following description includes systems, methods, and techniques that embody exemplary embodiments of the present invention. In the following description, for purposes of explanation, numerous specific details are set forth to provide a thorough understanding of the exemplary embodiments. However, it will be apparent to one skilled in the art that the subject matter of the present invention may be practiced without these specific details.

[0026] Some disclosures in this patent document include copyrighted material. The copyright holder reserves all copyrights, except to the extent that the patent document or patent disclosure appears in the patent file or records of the Patent and Trademark Office, and will not object to any copying of such patent document or patent disclosure by any person. The following notice applies to the software and data described or illustrated below and constituting part of this document: Lam Research Corporation, 2018-2020, All Rights Reserved. The term “wafer” as used herein as an example is intended to more generally include “substrate.” Substrates may include photomasks, flat panel displays, etc., which can also be processed in the systems and methods described herein.

[0027] Exemplary chambers in which several examples of the present disclosure may be used, with appropriate chamber modifications for film deposition and control testing, are shown in Figure 1 of the accompanying drawings. A typical plasma etching (or deposition) apparatus comprises a reactor containing a chamber through which one or more reactive gases flow. Within the chamber, the gases are typically ionized by high-frequency energy to form a plasma. The highly reactive ions of the plasma gas can react with materials such as polymer masks on the surface of a semiconductor wafer to be processed into an integrated circuit (IC). Prior to etching, the wafer is placed in the chamber and held in place by a chuck or holder that exposes the upper surface of the wafer to the plasma gas. There are several types of chucks known in the art. The chuck provides an isothermal surface and acts as a heat sink for the wafer. In one type, the semiconductor wafer is held in place for etching by mechanical clamping means. In another type of chuck, the semiconductor wafer is held in place by an electrostatic force generated by an electric field between the chuck and the wafer. The method of the present invention is applicable to both types of chucks.

[0028] Figure 1 shows a capacitively coupled plasma processing chamber 100, representing an exemplary plasma processing chamber of a type typically used for etching substrates. Referring to Figure 1, the chuck 102 represents a workpiece holder in which a substrate, such as a wafer 104, is positioned during etching. The chuck 102 can be implemented by any suitable chucking technique (e.g., electrostatic, mechanical, clamping, vacuum, etc.). During etching, the chuck 102 is typically supplied with dual RF frequencies (low frequency and high frequency), for example, 2 MHz and 27 MHz, simultaneously by a dual frequency source 106.

[0029] A vacuum transfer module (VTM) (not shown) can be used to place and center (or position) the wafer 104 on the chuck 102. Accurate wafer positioning or centering is typically a critical aspect when attempting to successfully perform specific processing operations on the wafer 104 within the processing chamber 100. These operations may include, for example, deposition, etching, and edge bevel removal (EBR). Other operations are also possible. In some examples, the VTM includes one or more robotic controls or arms for manipulating the wafer 104 as it is placed on the chuck 102. In the examples of this disclosure, the VTM robotic arm is guided by an array of cameras and feedback or other data generated by the VTM control module, which is further described below, during wafer placement and centering. One or more components of the processing chamber 100 can be used as datum points when determining the position or center of the wafer 104. In some examples, the proximity of one or more locations on the peripheral edge of the wafer 104 to the processing chamber components is used when determining the wafer center. In some examples, locations on two or three peripheral edges of wafer 104 can be used. In some examples, the datum component includes an edge ring 118.

[0030] Referring again to Figure 1, the upper electrode 108 is located on the wafer 104. The upper electrode 108 is grounded. Figure 1 shows an etching reactor where the surface of the upper electrode 108 is larger than the surface of the chuck 102 and the wafer 104. During etching, plasma 110 is formed from etchant gas supplied through the gas line 112 and discharged through the exhaust line 114. An electrical insulating ring 109 insulates the upper electrode 108 from the processing chamber 100.

[0031] The confinement ring 116 may be placed between the upper electrode 108 and the lower electrode, such as the chuck 102 in Figure 1. Generally, the confinement ring 116 helps to confine the etching plasma 110 to an area on the wafer 104, improving process control and ensuring repeatability.

[0032] When RF power is supplied from the dual-frequency source 106 to the chuck 102, equipotential lines are established on the wafer 104. Equipotential lines are electric field lines that traverse the plasma sheath between the wafer 104 and the plasma 110. In some examples, the equipotential planes and electric field lines are perpendicular to each other. Equipotential planes exist between the wafer 104 and the plasma 110. The electric field lines accelerate charged particles across these equipotential planes. During plasma processing, cations are accelerated across the equipotential lines and collide with the surface of the wafer 104, thereby providing desired etching effects such as improved etching directivity. Due to the geometric shapes of the upper electrode 108 and the chuck 102, the electric field lines may not be uniform across the wafer surface and may differ significantly at the edges of the wafer 104. Therefore, an edge (or focus) ring 118 is typically provided to improve process uniformity across the wafer surface. Referring to Figure 1, the wafer 104 is shown positioned within an edge ring 118, which can be formed from a suitable dielectric material such as ceramic, quartz, or plastic. Thus, the presence of the edge ring 118 allows equipotential field lines to be distributed substantially uniformly across the entire surface of the wafer 104.

[0033] The conductive shield 120 substantially surrounds the edge ring 118. The conductive shield 120 is configured to be substantially grounded within the processing chamber 100. The conductive shield 120 prevents the presence of unwanted equipotential lines outside the edge ring 118.

[0034] As described above, significant challenges can exist associated with the use of blanket wafers in wafer centering operations. Examples of this disclosure do not require blanket wafer images, but instead use images captured by a camera mounted on wafer 104 to measure and guide the wafer centering operation. The wafer centering operation can be performed on an edge ring 118 or a chuck 102 within a process module, such as an electrostatic chuck (ESC). In some examples, position data is sent as feedback to a wafer transfer module (e.g., VTM) to adjust its calibration until wafer 104 is properly centered on chuck 102.

[0035] One example of this disclosure involves performing in-situ measurements of a wafer 104 during a wafer centering operation and providing immediate feedback to the controller user interface (UI) of a control module. With the wafer 104 placed on a chuck 102 in a processing chamber 100, an array of one or more measuring cameras captures images that may include one or more locations or portions of the outer edge of the wafer 104 and at least one inner edge of the edge ring 118. Image processing software identifies the wafer periphery and inner edges of the edge ring 118 and calculates the separation distance, or gap, between them. In some examples, this measurement is performed at several points around the wafer 104. The measurement results are then used to adjust the VTM robot control for placing the wafer 104 on the chuck 102 in the processing chamber 100. By repeating the above procedure, the progress of the wafer centering operation can be quickly monitored.

[0036] Referring to Figure 2, a configuration 200 of one or more cameras (e.g., camera 1 and camera 2) associated with the processing chamber 100 can capture images and perform image measurements. In some examples, cameras 1 and 2 each have their respective fields of view 200' and 200'', which can detect the inner edge 202 of the edge ring 210 and the peripheral edge 204 of the wafer 206. The separation distance or gap 208 between the inner edge 202 and the peripheral edge 204 of the edge ring 210 can be detected and measured by cameras 1 and 2. A convenient exemplary configuration for performing gap measurement involves providing a vacuum seal window within the wall of the processing chamber 100 and positioning cameras 1 and 2 within the window. In some examples, image capture and gap measurement are performed during the startup and maintenance phases of the processing chamber 100. In other examples, cameras 1 and 2 are mounted on a robotic arm of a vacuum transfer module (VTM) to facilitate centering and gap measurement performed under the control of an operator of the processing chamber 100. In some examples, illumination is controlled during gap image measurement.

[0037] Configuration 200 in Figure 2 includes two cameras, but other configurations are possible. For example, a single movable camera can be positioned at two different locations to obtain fields of view 200' and 200'' respectively. In yet another exemplary configuration 1200 shown in Figure 12, a single movable camera can be moved between positions 1202, 1204, and 1206 to obtain or generate one or more fields of view 1200', 1200'', and 1200'' respectively at those camera positions. Some or all of the cameras in the various examples described herein may be fixed or movable. Some examples may include or generate a single field of view captured by a single camera that includes or encompasses a composite field of view, e.g., multiple subviews. Exemplary subviews may include those at positions 1202, 1204, and 1206 in Figure 12. Other combinations of fields of view and camera configurations are also possible.

[0038] An alternative camera configuration 300 is shown in Figure 3. The illustrated configuration includes three cameras 1, 2, and 3 (labeled 302, 304, and 306 in the figure) positioned to take images of an edge ring 310 and wafer 312 located inside a processing chamber, such as the processing chamber 100 in Figure 1. Each camera 1, 2, and 3 has its own field of view 300', 300'', and 300''''. The VTM 308 (not shown to scale) may be positioned adjacent to the processing chamber 100 being monitored. In some examples, a single VTM 308 has a rectangular footprint spanning an area large enough to serve multiple adjacent processing chambers 100. In some examples, a single VTM 308 has five processing chambers 100 positioned along each of its sides. The VTM308 (Figure 3) may include a robotic arm 310 (not shown to scale) for manipulating one or more cameras between the respective fields of view 302, 304, and 306. Since a single camera or multiple cameras can be mounted on the VTM arm 310, field of view or gap measurements can be established or performed at the operator's discretion or by an automated processor. In some examples, illumination of the field of view is controlled, for example, while performing gap measurements or when monitoring the field of view. While the configuration in Figure 3 includes three cameras 1-3, such measurements can be performed using a single moving camera or multiple stationary cameras.

[0039] Figure 4 shows exemplary images 402 and 404 of photographs captured by cameras 1 and 2 in various embodiments described herein. Image 402 on the left illustrates a relatively small gap 406 between the inner edge 202 of the edge ring 210 and the peripheral edge 204 of the wafer 206. Thus, camera 1 has detected that the wafer placement is relatively close to the edge ring 210. Image 404 on the right illustrates a larger gap 408 between the inner edge 202 of the edge ring 210 and the peripheral edge 204 of the wafer 206. Camera 2 has detected that the wafer placement is further away from the edge ring 210. In some examples, the ring gap 208 from the wafer to the edge in Figure 2 (or 406 and 408 in Figure 4) can be adjusted or set based on different VTM robot settings. Bare silicon (Si) wafers 206 (e.g.) can be used, but other types of wafers 206 are also possible. Other examples may include the use of a calibration wafer having markings indicating a reference angle and / or wafer radius, which in some examples may be provided in distinguishable colors within images 402 and 404. Information regarding gaps 406 and 408 (position data) may be dynamically transmitted as feedback to the VTM308 during the wafer centering operation. Based on the received feedback, the wafer position can be adjusted stepwise or continuously until a preset or predetermined gap value for the wafer center position is established.

[0040] Figures 5–8 show exemplary images of the peripheral edge 204 of the wafer 502 corresponding to the position of each camera adjacent to the relevant inner edge 202 of the edge ring 210 (for example, in fields 300', 300'', and 300'' captured by cameras 1, 2, and 3 in Figure 3). The wafer 502 is positioned on the chuck 102 in the processing chamber 100. Although the peripheral edges of the wafer 502 are represented by straight lines, it will be understood that in reality they are slightly curved. The position of the VTM 512 adjacent to the processing chamber 100 is shown in Figure 5. The VTM 512 is positioned similarly in each of the figures in Figures 6–8. In Figure 500 of Figure 5, the initial positions or datum positions 504, 506, and 508 of the upper, lower, and right edge of the wafer 502 are shown in Figure 5, respectively. The separation distance or top gap 510 (for the purposes of this example) may be correspondingly derived and recorded.

[0041] The image in Figure 6 shows the movement of a wafer in direction 602 under the control of the VTM512's robotic arm, away from the VTM512's position (Figure 5). The top gap 510 widens accordingly.

[0042] The image in Figure 7 shows the wafer movement to 702, returning to its initial position or datum wafer position towards VTM512. The size of the top gap 510 is restored accordingly.

[0043] For further purposes of this example, the initial side gap 704 (Figure 7) can be derived and recorded. The image in Figure 8 shows the movement of the wafer under the control of the VTM512 robotic arm in the rightward direction 802. The side gap 704 narrows accordingly. Position data representing such wafer movement, derived from top and side gap images captured by the array of cameras 1, 2, and 3, is dynamically sent back to the VTM512 control module to facilitate the identification and centering of the wafer 502 during wafer placement and centering operations.

[0044] Referring to Figure 9, the configuration 900 of the wafer 206 and edge ring 210 is shown. Using the edge ring 210 as a datum, the center of the wafer 206 of a known diameter (and therefore known radius) can be determined based on measurements of the top gap 510 and side gaps 704, or based on positions relative to the gaps 510 and 704. Based on images taken by cameras 1 and 2 shown in the figure, the separation distance or top gap 510 between a position X on the peripheral edge 204 of the wafer 206 and an adjacent position X' on the inner edge 202 of the edge ring 210 can be determined. The separation distance or side gap 704 can be determined in a similar manner for positions Y and Y'. For simplification, cameras 1 and 2 are shown in the camera positions in the right and lower quadrants, as shown in the figure, rather than in their actual positions in the upper and left quadrants where images of the top gap 510 and side gaps 704 are actually taken.

[0045] In some examples, the positions of points X' and Y' are known or can be derived based on known positions or dimensions of the edge ring 210, which can, for example, function as a datum component with respect to these points. The center 908 of the edge ring 210 can be correspondingly established as a reference for wafer centering and processing purposes.

[0046] Using the known positions of points X' and Y', the top and side gaps 510 and 704 can be applied, respectively, to determine the positions of points X and Y on the peripheral edge 204 of wafer 206. The radius of wafer 206 is known, and a conceptual circumference (or arc portion of the circumference) based on the wafer radius can correspondingly tangent around each point X and Y. The conceptual circumference of point X is labeled 902 and 904 with respect to point Y, respectively. The intersection of the conceptual circumferences 902 and 904 within the periphery of wafer 206 establishes the center of wafer 206 at center 910. Since it is understood that the center of wafer 206 lies within its periphery, the intersection of the circumferences 902 and 904 outside the periphery of wafer 206 (at point 906) can be discarded as an invalid result. The determined center 910 of wafer 206 can be compared, on a dynamic basis, with the true center 908 of the edge ring 210 to derive offset or position data 912.

[0047] In some examples, feedback based on offset data is provided to the VTM512 control module to adjust the position or path of the wafer 206 during wafer centering. During the wafer centering operation, positional adjustments to the wafer 206 may be performed by the VTM512 control module based on the determination of the top and side gaps 510 and 704, or the determination of the positions of the edge ring 210 and wafer centers 908 and 910, or based on a combination of both sets of data or parts thereof.

[0048] Figure 10 illustrates a scatter plot 1000 showing the measured changes in wafer centers obtained from camera measurements (solid ring dots 1002) and VTM robot setting value commands (dashed ring dots 1004). Lines 1006 and 1008 link the measured wafer centers 1002 to their associated robot setting values ​​1004. The relatively short line segment 1008, indicated by a solid contour, indicates that each measured wafer center 1002 is within the specifications of the VTM robot wafer setting value 1004. This reflects the robot repeatability specification described above. The relatively long line segment 1006 indicates that the measured wafer centers 1002 are, for example, within 133% of the VTM robot specification. Other precision margins may be used. The hash line 1010 indicates, for example, a single wafer measurement exceeding 133% of the robot setting value. The dotted line 1012 indicates, for example, a camera measurement that correctly captures an error in robot placement. Other indicators are also possible.

[0049] Therefore, in some examples, methods for centering a wafer are provided. Referring to Figure 11, a method 1100 for centering a wafer relative to a datum structure includes, in operation 1102, placing a camera configuration including at least two cameras adjacent to a wafer processing chamber, each of the at least two cameras having a field of view when positioned on the camera configuration, each field of view including the peripheral edge of the wafer and the peripheral edge of the datum structure; in 1104, receiving positional data from each of the at least two cameras and determining, in relation to each field of view, the gap size between the respective peripheral edges of the wafer and datum positions included in each field of view; and in 1106, adjusting the position of the wafer relative to the datum structure based on the respective determined gap sizes.

[0050] In some examples, the datum location includes the edge ring. In some examples, the datum location includes the chuck.

[0051] In some examples, method 1100 further includes providing a camera configuration on the wall of the wafer processing chamber.

[0052] In some examples, method 1100 further includes including a third camera in the camera configuration and providing positional data from the third camera to the processor in relation to each third field of view.

[0053] In some examples, method 1100 further includes comparing each determined gap size with each predetermined gap size, where each predetermined gap size is associated with the center position or desired position of the wafer relative to the datum structure or wafer processing chamber.

[0054] In some examples, Method 1100 further includes including a robotic arm of a vacuum transfer module (VTM) in the controller.

[0055] Accordingly, embodiments are provided for camera-based image detection for positioning a wafer relative to an edge ring 210 within a processing chamber 100. Examples of the disclosure may provide improved speed, cost, and accuracy. Some examples may facilitate rapid in-situ measurements during wafer positioning or centering operations. Typically, a blanket wafer is etched in a process module, and measurements are performed on the wafer 206 to determine wafer centering. In a fab where the wafer 206 is typically tracked, pre-measured, and moved, conventional measurement operations may require a given period of time to complete. In contrast, the process of the present invention can reduce that time to one-eighth. In laboratory process tools, using the methods disclosed herein, performing these operations may take only 12.5% ​​of the conventional time required in a fab.

[0056] Conventional wafer centering methods are typically time-consuming to complete and often involve blanket wafers. Several exemplary methods described herein require only a one-time cost. The camera measurement methods of this disclosure can, in some examples, determine wafer placement within the range of the VTM robot control setpoints in most cases. In all but one example in Figure 10, the camera measurement determined wafer placement within the range of the specifications of conventional back-side particle measurement. Embodiments can be configured or modified as needed by making changes to both the hardware and the image processing algorithms.

[0057] While embodiments have been described with reference to specific exemplary embodiments, it will be apparent that various modifications and changes can be made to these embodiments without departing from a broader range of embodiments. Therefore, this specification and the drawings should be considered in an exemplary rather than restrictive sense. The accompanying drawings, forming part of this specification, illustrate, not restrictively, specific embodiments in which the subject matter can be practiced. The illustrated embodiments are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other embodiments may be utilized, and other embodiments may be derived from the teachings disclosed in this specification, so as to enable structural and logical substitutions and modifications without departing from the scope of this disclosure. Therefore, this detailed description should not be interpreted in a restrictive sense, and the scope of the various embodiments is defined solely by the appended claims and all equivalents to which such claims are entitled.

[0058] Such embodiments of the subject matter of the present invention may be referred to herein individually and / or collectively by the term “invention,” but this is merely a matter of convenience and is not intended to spontaneously limit the scope of this application to any single invention or inventive concept (if more are actually disclosed). Therefore, while specific embodiments are illustrated and described herein, it should be understood that any configuration calculated to achieve the same objective may substitute for any particular embodiment shown. This disclosure is intended to cover all possible adaptations or variations of various embodiments. Combinations of the above embodiments with other embodiments not specifically described herein will be apparent to those skilled in the art upon consideration of the above description. This disclosure may be implemented in the following forms: [Form 1] A system for positioning a wafer relative to a datum structure, A camera configuration comprising at least two cameras, each of which, when positioned in the camera configuration, includes a field of view, each field of view including the peripheral edge of the wafer and the peripheral edge of the datum structure, A processor that receives positional data from each of the at least two cameras and determines, in relation to each field of view, the gap size between the respective peripheral edges of the wafer and datum positions included in each field of view, A controller adjusts the position of the wafer relative to the datum structure based on the respective gap sizes determined above. A system that includes these features. [Form 2] The system described in Form 1, The datum position is part of the system, including the edge ring. [Form 3] The system described in Form 1, The aforementioned datum position is a system including a chuck. [Form 4] The system described in Form 1, The aforementioned camera configuration is a system installed on the wall of a wafer processing chamber. [Form 5] The system described in Form 1, The camera configuration includes a third camera, the third camera providing positional data related to each of the third fields of view to the processor. [Form 6] The system described in Form 1, A system in which each of the determined gap sizes is compared with each predetermined gap size, and each predetermined gap size is associated with the central position or a desired position of the wafer relative to the datum structure. [Form 7] The system described in Form 1, The controller is part of a system including a robotic arm of a vacuum transfer module (VTM). [Form 8] The system described in Form 1, The processor is a system that identifies the center of the wafer based on the respective gap sizes determined. [Form 9] A method for positioning a wafer relative to a datum structure, A camera configuration comprising at least two cameras is placed adjacent to the wafer processing chamber, each of the at least two cameras having a field of view when positioned on the camera configuration, and each field of view having a peripheral edge of the wafer and a peripheral edge of the datum structure. Receiving positional data from each of the at least two cameras, and determining the gap size between the respective peripheral edges of the wafer and datum positions included in each field of view, Based on the respective gap sizes determined above, the position of the wafer relative to the datum structure is adjusted. Methods that include... [Form 10] The method described in Embodiment 9, The datum position includes an edge ring, in a manner. [Form 11] The method described in Embodiment 9, The datum position includes a method including a chuck. [Form 12] The method described in Embodiment 9, A method further comprising providing the camera configuration on the wall of the wafer processing chamber. [Form 13] The method described in Embodiment 9, A method further comprising including a third camera in the camera configuration, and providing positional data from the third camera to the processor in relation to each of the third fields of view. [Form 14] The method described in Embodiment 9, A method further comprising comparing each of the determined gap sizes with each predetermined gap size, wherein each predetermined gap size is associated with the central position or a desired position of the wafer relative to the datum structure or the wafer processing chamber. [Form 15] The method described in Embodiment 9, A method further comprising including a robotic arm of a vacuum transfer module (VTM) in the controller. [Form 16] A system for positioning a wafer relative to a datum structure, A camera configuration comprising one or more cameras, each of which, when positioned in the camera configuration, includes a field of view, and each field of view includes the peripheral edge of the wafer and the peripheral edge of the datum structure. A processor that receives positional data from one or each of the cameras and determines, in relation to each field of view, the gap size between the respective peripheral edges of the wafer and datum positions included in each field of view, A controller adjusts the position of the wafer relative to the datum structure based on the respective gap sizes determined above. A system that includes these features. [Form 17] The system described in Embodiment 16, The system includes one or more cameras, including a single movable camera. [Form 18] The system described in Embodiment 17, The aforementioned single movable camera is attached to a robotic arm as part of the system. [Form 19] The system described in form 18, The system includes a robotic arm that is attached to a vacuum transfer module (VTM). [Form 20] The system described in Embodiment 16, The aforementioned camera configuration is a system installed on the wall of a wafer processing chamber.

Claims

1. A system for positioning a wafer relative to a datum structure, A camera configuration comprising at least two cameras, each of which, when positioned in the camera configuration, includes a field of view, each field of view including the peripheral edge of the wafer and the peripheral edge of the datum structure, A processor that receives positional data from each of the at least two cameras, determines the gap size between the respective peripheral edges of the wafer and datum positions included in each field of view, and determines the offset between the center position of the datum structure and the center position of the wafer, A controller adjusts the position of the wafer relative to the datum structure based on the respective gap sizes and offsets determined above. Equipped with, The processor, in order to determine the offset, (i) Identification of two known positions, the top position and the side position, at the peripheral edge of the datum structure, (ii) Identification of the top gap, which is the gap size at the top position, and the side gap, which is the gap size at the side position, in the field of view of the at least two cameras. (iii) Identifying two points on the peripheral edge of the wafer using the top gap, the side gap, and the two known positions, (iv) Identifying two circles centered on the two points and having the same radius as the wafer, (v) A system that performs the following: identifying the intersection of the two circles located inside the wafer as the center position of the wafer.

2. The system according to claim 1, The datum position is part of the system, including the edge ring.

3. The system according to claim 1, The aforementioned datum position is a system including a chuck.

4. The system according to claim 1, The aforementioned camera configuration is a system installed on the wall of a wafer processing chamber.

5. The system according to claim 1, The camera configuration includes a third camera, the third camera providing positional data related to each of the third fields of view to the processor.

6. The system according to claim 1, A system in which each of the determined gap sizes is compared with each predetermined gap size, and each predetermined gap size is associated with the central position or a desired position of the wafer relative to the datum structure.

7. The system according to claim 1, The controller is part of a system including a robotic arm of a vacuum transfer module (VTM).

8. The system according to claim 1, The processor is a system that identifies the center of the wafer based on the respective gap sizes determined.

9. A method for positioning a wafer relative to a datum structure using a processor and a controller, A camera configuration comprising at least two cameras is mounted adjacent to the wafer processing chamber, each of the at least two cameras having a field of view when positioned on the camera configuration, and each field of view having a peripheral edge of the wafer and a peripheral edge of the datum structure. The processor receives positional data from each of the at least two cameras, determines the gap size between the respective peripheral edges of the wafer and datum positions included in each field of view, and determines the offset between the center position of the datum structure and the center position of the wafer, The controller adjusts the position of the wafer relative to the datum structure based on the respective determined gap sizes and offsets. Includes, Determining the aforementioned offset means (i) Identifying two known positions, the top position and the side position, at the peripheral edge of the datum structure, (ii) Identifying the top gap, which is the gap size at the top position, and the side gap, which is the gap size at the side position, in the field of view of at least two cameras. (iii) Identifying two points on the peripheral edge of the wafer using the top gap, the side gap, and the two known positions, (iv) Identifying two circles centered on the two points and having the same radius as the wafer, (v) Identifying the intersection of the two circles located inside the wafer as the center position of the wafer, Methods that include...

10. The method according to claim 9, The datum position includes an edge ring, in a manner.

11. The method according to claim 9, The datum position includes a method including a chuck.

12. The method according to claim 9, A method further comprising providing the camera configuration on the wall of the wafer processing chamber.

13. The method according to claim 9, A method further comprising including a third camera in the camera configuration, and providing positional data from the third camera to the processor in relation to each of the third fields of view.

14. The method according to claim 9, A method further comprising comparing each of the determined gap sizes with each predetermined gap size, wherein each predetermined gap size is associated with the central position or a desired position of the wafer relative to the datum structure or the wafer processing chamber.

15. The method according to claim 9, A method further comprising including a robotic arm of a vacuum transfer module (VTM) in the controller.

16. A system for positioning a wafer relative to a datum structure, A camera configuration comprising one or more cameras, each of which, when positioned in the camera configuration, includes a field of view, and each field of view includes the peripheral edge of the wafer and the peripheral edge of the datum structure. A processor that receives positional data from one or each of the cameras, determines the gap size between the respective peripheral edges of the wafer and datum positions included in each field of view, and determines the offset between the center position of the datum structure and the center position of the wafer, A controller adjusts the position of the wafer relative to the datum structure based on the respective gap sizes and offsets determined above. Equipped with, The processor, in order to determine the offset, (i) Identification of two known positions, the top position and the side position, at the peripheral edge of the datum structure, (ii) Identification of the top gap, which is the gap size at the top position, and the side gap, which is the gap size at the side position, in the field of view of the at least two cameras. (iii) Identifying two points on the peripheral edge of the wafer using the top gap, the side gap, and the two known positions, (iv) Identifying two circles centered on the two points and having the same radius as the wafer, (v) A system that performs the following: identifying the intersection of the two circles located inside the wafer as the center position of the wafer.

17. The system according to claim 16, The system includes one or more cameras, including a single movable camera.

18. The system according to claim 17, The aforementioned single movable camera is attached to a robotic arm as part of the system.

19. The system according to claim 18, The system includes a robotic arm that is attached to a vacuum transfer module (VTM).

20. The system according to claim 16, The aforementioned camera configuration is a system installed on the wall of a wafer processing chamber.

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