Automatic teaching of substrate handling for production and process control tools

Abstract

A teaching substrate is loaded into a load port of an equipment front end module (EFEM) of a fabrication or inspection tool. The EFEM includes a substrate handling robot. The teaching substrate includes a plurality of sensors and one or more wireless transceivers. The tool includes a plurality of workstations. With the teaching substrate positioned in the EFEM, the substrate handling robot moves along an initial route and wirelessly receives sensor data from the teaching substrate. Based at least in part on the sensor data, a modified route different from the initial route is determined. The substrate handling robot moves along the modified route to handle the teaching substrate. Based at least in part on the sensor data, positions of the plurality of workstations are determined.

Description

[0001] Related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 897,545, filed on September 9, 2019, which is incorporated herein by reference in its entirety for all purposes. Technical Field

[0003] The present invention relates to substrate (e.g., semiconductor wafer) handling, and more particularly to methods and systems for teaching substrate handling robots. Background Art

[0004] A tool used to fabricate or inspect substrates (e.g., semiconductor wafers) may include an equipment front-end module (EFEM). The EFEM includes a substrate handling robot for moving substrates between various workstations within the tool. As part of setting up or modifying the tool, a teach-in process is performed to enable the substrate handling robot to handle substrates (e.g., accurately and reliably move substrates between workstations). The typical teach-in process involves significant tool downtime, which reduces throughput. Furthermore, some steps in the typical teach-in process are performed by a technician. Summary of the Invention

[0005] Accordingly, there is a need for fast, efficient, and accurate automation techniques for teaching substrate handling robots.

[0006] In some embodiments, an apparatus includes: a substrate to be loaded into an equipment front end module (EFEM) of a fabrication or inspection tool; a first camera positioned on the substrate to image an area on one side of the substrate; a second camera positioned on the substrate to image an area beneath the substrate; and one or more wireless transceivers positioned on the substrate to transmit images captured by the first and second cameras.

[0007] In some embodiments, a method includes loading a teaching substrate into a load port of an EFEM of a fabrication or inspection tool. The EFEM includes a substrate handling robot. The teaching substrate includes a plurality of sensors and one or more wireless transceivers. The tool includes a plurality of workstations. With the teaching substrate positioned in the EFEM, the substrate handling robot moves along an initial route and wirelessly receives sensor data from the teaching substrate. Based at least in part on the sensor data, a modified route different from the initial route is determined. The substrate handling robot moves along the modified route to transport the teaching substrate. Based at least in part on the sensor data, positions of the plurality of workstations are determined. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] For a better understanding of the various described embodiments, reference should be made to the following detailed description taken in conjunction with the accompanying drawings.

[0009] Figure 1 is a block diagram of a fabrication or inspection tool for fabricating or inspecting a substrate.

[0010] Figure 2A is a plan view of a teaching substrate with a sensor and a light guide panel to be used for automated teaching of substrate handling in a fabrication or inspection tool, according to some embodiments.

[0011] Figure 2B According to some embodiments Figure 2A A perspective view of an example of a teaching substrate showing a light guide panel and camera while omitting other components.

[0012] Figure 3 is a plan view of a teaching substrate having cameras and a separate light guide panel to provide illumination for each of the cameras, according to some embodiments.

[0013] Figure 4 is a plan view of a teaching substrate having a camera and LEDs to provide illumination for the camera, according to some embodiments.

[0014] Figure 5A and 5B are corresponding side cross-sectional and plan views of a teaching substrate and a camera's field of view on the teaching substrate according to some embodiments.

[0015] Figure 6 is an optical diagram of a triangulator that may be used as a distance measurement sensor on a teaching substrate, according to some embodiments.

[0016] Figure 7 is an optical diagram of a triangulator with tilt cancellation that may be used as a distance measurement sensor on a teaching substrate, according to some embodiments.

[0017] Figure 8 is an optical diagram of a triangulator including a camera and usable as a distance measurement sensor on a teaching substrate, according to some embodiments.

[0018] Figure 9 is a flow chart illustrating a method of performing automated teaching of substrate handling according to some embodiments.

[0019] Figure 10 is a flow chart illustrating a method of performing automated teaching of substrate handling according to some embodiments.

[0020] Figure 11is a flow chart illustrating a method for performing automated teaching of substrate handling in a load port according to some embodiments.

[0021] Figure 12 is an image captured by a camera on a teach substrate of a target fixture and an end effector in a substrate pod in a load port according to some embodiments.

[0022] Figure 13 is a flow chart illustrating a method of performing automatic teaching of substrate handling for a pre-aligner according to some embodiments.

[0023] Figure 14A is a side image of a pre-aligner taken by a camera on a teaching substrate according to some embodiments.

[0024] Figure 14B is a top image of a pre-aligner taken by a camera on a teaching substrate according to some embodiments.

[0025] Figure 15 is a flow chart illustrating a method of performing automatic teaching of a tool chuck in a tool chamber according to some embodiments.

[0026] Figure 16 is a flow chart illustrating an alternative method of performing automatic teaching of a tool chuck in a tool chamber according to some embodiments.

[0027] Figure 17 is a plan view of a tool chuck according to some embodiments.

[0028] Figure 18 is a block diagram of electronic components of a substrate according to the teachings of some embodiments.

[0029] Figure 19 is a block diagram of a computer communicatively coupled to (eg, part of) a fabrication or inspection tool, according to some embodiments.

[0030] Figure 20A and 20B 1 and 2 are perspective and plan views, respectively, of a teaching substrate with four cameras according to some embodiments.

[0031] Like reference numerals designate corresponding parts throughout the drawings and description. DETAILED DESCRIPTION

[0032] Reference will now be made in detail to various embodiments, examples of which are illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the various described embodiments. However, it will be apparent to those skilled in the art that the various described embodiments can be practiced without these specific details. In other instances, well-known methods, process steps, components, circuits, and networks have not been described in detail to avoid unnecessarily obscuring aspects of the embodiments.

[0033] Figure 1 1 is a block diagram of a fabrication or inspection tool 100 for fabricating or inspecting substrates. Tool 100 may also be referred to as a production tool (if it performs substrate fabrication) or a process control tool (if it performs substrate inspection). Tool 100 includes an equipment front end module (EFEM) 101 having a substrate handling robot 108 for handling a substrate 102. In some embodiments, substrate 102 is a semiconductor wafer and tool 100 is a wafer fabrication or wafer inspection tool. In some embodiments, substrate 102 is a reticle (i.e., a photomask) and tool 100 is a reticle fabrication or reticle inspection tool. Tool 100 may be used in a substrate fabrication facility known as a wafer fab.

[0034] The substrate handling robot 108 has an end effector 109 to pick up the substrate 102 and move it through the EFEM 101 between the various workstations of the tool 100. Examples of workstations include, without limitation, the load port 105 in the tool chamber 111, the pre-aligner 106, and the workstation 107. In some embodiments, the pre-aligner 106 is omitted from the tool 100. The substrate handling robot 108 has various degrees of freedom; for example, it can rotate, translate, raise, and / or lower the substrate 102 on the end effector 109. The substrate handling robot 108 can extend and retract the end effector 109.

[0035] The tool 100 may include one or more load ports 105 for loading substrates 102 into the tool 100. The substrates 102 are carried in pods 104 (e.g., vertically stacked in the pods 104). Pods 104 may also be referred to as substrate pods, front-opening unified pods (FOUPs), cassettes, magazines, or boats (e.g., wafer boats). Each pod 104 may contain multiple substrates 102. Pods 104 may be loaded into the load ports 105 manually by a user (e.g., a technician or operator) or automatically using robotic equipment in the wafer fab (e.g., an aerial transport). A substrate handling robot 108, using an end effector 109, picks up a substrate 102 from the pod 104 loaded into the load port 105 and transports the substrate 102 to a pre-aligner 106. The pre-aligner 106 includes a chuck on which the substrate handling robot 108 places the substrate 102. The pre-aligner 106 rotates the substrate 102 to a specified orientation (e.g., relative to a notch on the substrate 102). The pre-aligner 106 may notify the substrate handling robot 108 to correct its position so that the substrate handling robot 108 can pick up the substrate 102 in the middle. The substrate handling robot 108 picks up the substrate 102 from the pre-aligner 106 using an end effector 109 and moves the substrate 102 to a workstation 107 in a tool chamber 111. The workstation 107 includes a chuck. The tool chamber 111 is separated from the EFEM 101 by a hatch 110. The hatch 110 may be opened and closed or may always be open (i.e., may be an opening). The substrate handling robot 108 inserts the substrate 102 through the hatch 110 and places the substrate 102 on the chuck of the workstation 107. (However, in some embodiments, the teaching substrate (e.g., the teaching substrate 200, as described below) may be positioned relative to the substrate 102 in the workstation 107.) Figures 2A to 2B ;300, Figure 3 ;400, Figure 4 ;500, Figures 5A to 5B ; 2000, Figures 20A to 20B ) is not placed on the chuck of the workstation 107 to reduce contamination. ) The substrate 102 is processed or inspected in the tool chamber 111 and then returned to the pod 104 by reversing the movement used to transfer the substrate 102 to the tool chamber 111. According to some embodiments, the tool 100 is shown with a single tool chamber 111 and corresponding workstation 107, but may include multiple tool chambers 111 with respective workstations 107. For example, the tool 100 may be a cluster tool.

[0036] A computer 103, which may be referred to as a front-end computer (FEC), controls the tool 100. For example, the computer 103 controls the movement of the substrate handling robot 108 and the pre-aligner 106, and controls the opening and closing of the load port 105 and the hatch 110. The computer 103 may communicate with the tool 100 via a wired and / or wireless connection. Although the computer 103 is shown as separate from and communicatively coupled to the tool 100, the computer may be included in the tool 100.

[0037] An automatic teaching (i.e., training) process is performed to identify the positions of workstations in tool 100 and determine a route for moving substrate 102 through tool 100. The automatic teaching process can be performed when tool 100 is first installed and after tool 100 has been modified. For example, the automatic teaching process can be performed after a new component that may affect the movement of substrate 102 (e.g., a potential obstacle to the movement of substrate 102) is installed in tool 100. The automatic teaching process is performed using a teaching substrate that is loaded into EFEM 101 and moved through EFEM 101. The teaching substrate has sensors used in the automatic teaching process. Data from the sensors is wirelessly transmitted from the teaching substrate to computer 103. Computer 103 can wirelessly transmit commands to the teaching substrate and substrate handling robot 108, which execute the commands. The commands transmitted to the teaching substrate include instructions for the sensors on the teaching substrate. The positions of workstations in tool 100 and the route for moving substrate 102 through tool 100 are determined based at least in part on the sensor data.

[0038] Figure 2A is a plan view of a teaching substrate 200 according to some embodiments. The teaching substrate 200 is sized to be loaded into the tool 100 (for example, by being placed in a pod 104 that is loaded into the load port 105). Figure 1 ). In some embodiments, tool 100 is a semiconductor-wafer fabrication or inspection tool and teaching substrate 200 is shaped like a semiconductor wafer (e.g., is round and has the same diameter as a production semiconductor wafer fabricated or inspected using tool 100, e.g., 300 mm, 450 mm, 150 mm, 200 mm, etc.). In some embodiments, tool 100 is a reticle fabrication or inspection tool and teaching substrate 200 is shaped like a reticle (e.g., is a blank reticle with components on its top surface). Teaching substrate 200 (or other teaching substrates disclosed herein) including its components can have a weight that differs from a production substrate by only a specified amount. For example, the teaching substrate can be approximately 100 grams heavier than a production substrate (e.g., within 10% or 5%).

[0039] The teaching substrate 200 has various sensors including: cameras 203, 208, and 210; a distance measurement (DM) sensor (i.e., range sensor) 205; and an inertial measurement unit (IMU) 206. (Equivalently, the sensors may be referred to as being on the teaching substrate 200.) The IMU 206 may include one or more accelerometers. The teaching substrate 200 has other components including one or more processors and memories (e.g., processor 1802 and memory 1830, Figure 18 ) includes a computing unit (CU) 201 (e.g., a microcontroller with embedded memory), one or more wireless transceivers (Tx / Rx) 207, light guide panels 204 and 209, and a battery 202. The battery 202 powers the sensors, computing unit 201, one or more wireless transceivers 207, light guide panels 204 and 209, and any other electronic components on the teaching substrate 200. The sensors and other components, or portions thereof, may be disposed (e.g., mounted) on top of the teaching substrate 200, leaving the bottom of the teaching substrate 200, or a portion thereof, clear for handling by the end effector 109 of the substrate handling robot 108 and placement on the tool 100 ( Figure 1 ) on the chuck in the ).

[0040] The teaching substrate 200 has a camera oriented to image an area below the teaching substrate 200 in the tool 100 (e.g., in the EFEM 101). The camera 203 disposed at or adjacent to the edge of the teaching substrate 200 can image an area below the edge of the teaching substrate 200 (e.g., the area in the field of view 506). Figures 5A to 5B ) imaging. The camera 208, which may be positioned at the center of the teaching substrate 200, may image an area below the center of the teaching substrate 200 (eg, an area in the field of view 504, Figures 5A to 5B) imaging. In some embodiments, the cameras 203 and 208 are mounted on the top side of the teaching substrate 200 and the teaching substrate 200 is transparent, allowing the cameras 203 and 208 to capture images of the area below the teaching substrate 200 through the teaching substrate 200. Alternatively, the teaching substrate 200 may have corresponding holes through which the top-mounted cameras 203 and / or 208 capture images of the area below the teaching substrate 200. For example, the teaching substrate 200 has a first hole to provide the camera 208 with a view of the area below the center of the teaching substrate 200 and a second hole to provide the camera 203 with a view of the area below the edge of the teaching substrate 200. In some embodiments, the cameras 203 and / or 208 are facing downward on the top side of the teaching substrate 200 (i.e., facing downward relative to the teaching substrate 200). Alternatively, cameras 203 and / or 208 face sideways on the top side of teaching substrate 200 and have associated mirrors (e.g., 45° mirrors) that direct the respective fields of view of cameras 203 and / or 208 underneath teaching substrate 200 (e.g., mirror 2006, Figures 20A to 20B ).

[0041] The camera 210 is disposed at or adjacent to a side of the teaching substrate 200 (e.g., an edge of the teaching substrate 200 opposite the edge of the camera 203) and can enable viewing in the tool 100 (e.g., in the EFEM 101) of an area on the side of the teaching substrate 200 (e.g., an area in the field of view 502). Figures 5A to 5B ) imaging. In some embodiments (e.g., some embodiments in which the teaching substrate 200 is wafer-shaped), cameras 203, 208, and 210 are positioned along a diameter 211 of the teaching substrate 200, with cameras 203 and 210 on opposite sides of camera 208. Camera 210 can be disposed (e.g., mounted) on the top side of the teaching substrate 200, facing sideways and outward relative to the teaching substrate 200, such that it has a field of view to the side of the teaching substrate 200.

[0042] Light guide panels 204 and 209 serve as illumination for cameras 203, 208, and 210. Light guide panel 204 faces downward relative to teaching substrate 200 to illuminate an area below the center of teaching substrate 200 for imaging by camera 208 and to illuminate an area below the edge of teaching substrate 200 for imaging by camera 203. For example, light guide panel 204 is on the top side of teaching substrate 200 and faces downward to provide illumination through the transparent teaching substrate 200. Other components (e.g., computing unit 201, distance measurement sensor 205, IMU 206, wireless transceiver 207, and / or battery 202) may be at least partially disposed above light guide panel 204. Light guide panel 209, which may be located behind camera 210, faces sideways and outward relative to teaching substrate 200 to illuminate an area on the side of teaching substrate 200 for imaging by camera 210. In some embodiments, each of light guide panels 204 and 209 contains a plurality of light emitting diodes (LEDs). For example, light guide panel 204 may contain LEDs along its straight sides 212. Light guide panel 209 may contain LEDs along respective sides, e.g., longitudinal edges parallel to the surface of teaching substrate 200. For each of light guide panels 204 and 209, illumination from these LEDs is coupled into the light guide and emitted (e.g., uniformly) across the panel surface.

[0043] Figure 2B is a perspective view of an example of a substrate 200 according to the teachings of some embodiments. Figure 2B The perspective view of FIG shows cameras 203, 208 and 210 and light guide panels 204 and 209. Other components of the teaching substrate 200 are omitted to avoid obscuring portions of the light guide panels 204 and 209. Figure 2B In the example of , the camera 210 is mounted behind the light guide panel 209 (ie, on the back side of the light guide panel 209). The light guide panel 209 may include an aperture (by Figure 2B 200) to provide the camera 210 with a field of view 502 ( Figures 5A to 5B ). Similarly, cameras 203 and 208 are mounted on the light guide panel 204 (ie, on the back side of the light guide panel 204), which may include an aperture (formed by Figure 2B 203 and 208 are covered in the teaching substrate 200 to provide the camera 203 with fields of view 506 and 504 ( Figures 5A to 5B ).

[0044] The teaching substrate 200 uses a single light guide panel 204 to provide illumination for cameras 203 and 208. Alternatively, according to some embodiments, a separate light guide panel is used to provide illumination for each of cameras 203 and 208, such as Figure 3 As shown in . Figure 33 is a plan view of a teaching substrate 300 including a light guide panel 302 for camera 203, a light guide panel 304 for camera 208, and a light guide panel 306 for camera 210. Light guide panel 302 illuminates a field of view 506 ( Figures 5A to 5B ). The light guide panel 304 illuminates the field of view 504 of the camera 208 ( Figures 5A to 5B ). The light guide panel 306 illuminates the field of view 502 of the camera 210 ( Figures 5A to 5B ).

[0045] In some embodiments, the teaching substrate includes cameras on different sides (eg, on opposite sides along diameter 211 ) oriented to image the area beneath the teaching substrate 200 in the tool 100 (eg, in the EFEM 101 ). Figure 20A and 20B 2002 are perspective and plan views, respectively, of a teaching substrate 2000 including cameras 203, 208, and 210, and further including a fourth camera 2002 oriented to image an area beneath the side of the teaching substrate opposite camera 203 (e.g., to image an area beneath camera 210). Camera 203 may thus be on the opposite side of camera 208 from camera 2002 (e.g., along the diameter of the teaching substrate 2000). Cameras 203 and 2002 are side-facing and have associated mirrors 2006 and 2004 (e.g., 45° mirrors), respectively, that direct the respective fields of view of cameras 203 and 2002 downward beneath the teaching substrate 200. (Alternatively, cameras 203 and 2002 may be downward-facing). According to some embodiments, camera 208 is downward-facing. (Alternatively, camera 208 may also be side-facing, with associated mirrors that direct its field of view downward beneath the teaching substrate 200.)

[0046] In some embodiments, the teaching substrate 2000 also includes light guide panels 204 and 209. The light guide panel 204 provides illumination for the cameras 203, 208, and 2002. (Alternatively, by a method similar to Figure 3 , each of the cameras 203, 208, and 2002 may have its own light guide panel, and / or may use other lighting devices (e.g., LEDs). ) The light guide panel 209 (or other lighting devices, such as LEDs) provides illumination for the camera 210. The teaching substrate 2000 may include a distance measurement sensor 205 (e.g., two distance measurement sensors 205 adjacent to the mirrors 2004 and 2006, respectively). For clarity, the distance measurement sensor 205 is shown in FIG. Figures 20A to 20B Other components of the teaching substrate 2000 (eg, computing unit 201, IMU 206, wireless transceiver 207, and battery 202) are omitted.

[0047] By including the camera 2002 and the distance measurement sensor 205 on the same side of the teaching substrate 2000 as the camera 210 (e.g., adjacent to the camera 210), a facing-down image and downward distance measurement can be obtained for an area imaged using the camera 210 without first rotating the teaching substrate 2000 using the pre-aligner 106. The teaching substrate 2000 can thus be used in a tool 100 that does not have a pre-aligner 106.

[0048] In some embodiments, other types of lighting devices are used instead of or in addition to the light guide panels used to provide illumination for cameras 203 , 208 , and 210 . Figure 4 FIG. 4 is a plan view of a teaching substrate 400 having LEDs for providing such illumination according to some embodiments. LEDs 402 face downward relative to the teaching substrate 400 to illuminate areas below the center and edges of the teaching substrate 400 (e.g., illuminating fields of view 506 and 504, Figures 5A to 5B ) to provide illumination for cameras 203 and 208. The teaching substrate 200 may be transparent or may have holes through which light from corresponding LEDs 402 passes. LEDs 404 face sideways and outward relative to the teaching substrate 400 to illuminate areas on the sides of the teaching substrate 400 (e.g., illuminating field of view 502, Figures 5A to 5B ) to provide illumination for camera 210. In some embodiments, different LEDs 402 face downward at different angles to provide different illumination angles. Similarly, different LEDs 404 can face outward at different angles to provide different illumination angles.

[0049] In some embodiments, a teaching substrate has multiple light sources (e.g., LEDs) and a diffuser to even out the light from the multiple light sources. For example, the teaching substrate may have an LED array and a diffuser positioned between the array and the area to be illuminated to even out the light from the array. The even light illuminates the field of view of one or more cameras. For example, the multiple light sources face downward and the diffuser is positioned between the multiple light sources and the top surface of the transparent teaching substrate.

[0050] Figure 5A and 5B Respective fields of view 502 , 504 , and 506 of cameras 210 , 208 , and 203 are shown in accordance with some embodiments. Figure 5A is a side cross-sectional view of a teaching substrate 500, which may be a teaching substrate 200 ( Figures 2A to 2B )、300( Figure 3 ) or 400( Figure 4 ) instance. Figure 5B is a plan view of the teaching substrate 500. Figure 5A and 5B Teaching of other components of the substrate 500 is omitted.

[0051] Return to Figure 2A 、 3 and 4, teaching substrate 200 ( Figure 2A )、300( Figure 3 ) or 400( Figure 4 ) transmits sensor data from the various sensors on the teaching substrate 200 to the computer 103 ( Figure 1 ) and receives commands from computer 103. One or more transceivers 207 provide commands to computing unit 201, which executes the commands (e.g., causes the corresponding sensors to perform the operations specified by the commands). Sensor data includes: images from cameras 203, 208, and / or 210; distance measurements from distance measurement sensor 205; and / or movement measurements from IMU 206 (e.g., acceleration measurements from one or more accelerometers in IMU 206). In some embodiments, one or more wireless transceivers 207 include a transceiver for a wireless local area network (WLAN) and / or a transceiver for a personal area network (PAN). For example, one or more wireless transceivers 207 include a WiFi transceiver and / or a Bluetooth transceiver. WiFi provides higher bandwidth than Bluetooth and therefore provides more efficient transmission of sensor data. However, the fab may restrict the use of WiFi, in which case Bluetooth or another PAN protocol may be used.

[0052] In some embodiments, the distance measurement sensor 205 is positioned relative to the teaching substrate (e.g., the teaching substrate 200, Figure 2A ;300, Figure 3 ;400, Figure 4 ; 2000, Figures 20A to 20B ) facing downward to measure the distance (e.g., axial distance) to a surface below the teaching substrate (e.g., a surface below and parallel to the teaching substrate). In some embodiments, the distance measurement sensor 205 is positioned relative to the teaching substrate (e.g., the teaching substrate 200, Figure 2A ;300, Figure 3 ;400, Figure 4 ; 2000, Figures 20A to 20B ) facing sideways and outwards to measure the distance from a surface next to the teaching substrate. In some embodiments, the teaching substrate includes both a downward facing distance measurement sensor 205 and a sideways, outward facing distance measurement sensor 205.

[0053] The distance measurement sensor 205 may be (or include) a triangulator. Figure 66 is an optical diagram of a triangulator 600 that can be used as a distance measurement sensor 205 according to some embodiments. The triangulator includes a collimated light source (e.g., a laser) 602, a cylindrical lens 604 (or alternatively, a spherical lens or a Fresnel lens), a folding mirror (i.e., tilted mirror) 606 (e.g., a 45° mirror), and a segmented photodiode 608 (e.g., a two-element or four-element photodiode). The collimated light beam from the collimated light source 602 is focused by the cylindrical lens 604 and directed downward (away from the surface) by the folding mirror 606. Figure 6 The surface reflection is folded back by the fold mirror 606 to Figure 6 6 and directed by cylindrical lens 604 to a segmented photodiode 608. Segmented photodiode 608 is positioned so that if the optical distance from cylindrical lens 604 to the surface is equal to the focal length of cylindrical lens 604 (i.e., the surface is in the focal plane), each cell of segmented photodiode 608 receives light of equal intensity. If the surface is at a different distance, each cell of segmented photodiode 608 receives light of a different intensity than the other cells. Using the intensity ratios between the cells and the calibration data of triangulator 600, the distance to the surface can be determined.

[0054] Figure 7 FIG2 is an optical diagram of a triangulator 700 that can be used as a distance measurement sensor 205 according to some embodiments. Although measurements obtained using the triangulator 600 can be affected by the tilt of a surface relative to a teaching substrate, the triangulator 700 allows the effects of the tilt to be canceled. The triangulator 700 includes a cylindrical lens 604 (or alternatively, a spherical lens or a Fresnel lens) and a folding mirror 606 (e.g., a 45° mirror). The triangulator 700 also includes two collimated light sources (e.g., lasers) 602-1 and 602-2, a pair of beam splitters 610-1 and 610-2, and a pair of segmented photodiodes 608-1 and 608-2 (e.g., two-element or four-element diodes). The collimated light sources 602-1 and 602-2 generate respective collimated light beams that are reflected by the beam splitters 610-1 and 610-2 toward the cylindrical lens 604. The beams are focused by the cylindrical lens 604 and folded downward toward the surface by the folding mirror 606. The surface reflection is folded back by fold mirror 606 to Figure 76 and directed by cylindrical lens 604 to beam splitters 610-2 and 610-1, which provide (e.g., transmit) respective reflected beams to segmented photodiodes 608-2 and 608-1. The beam from collimated light source 602-1 is initially reflected by beam splitter 610-1 and, after reflection from the surface, is provided by beam splitter 610-2 to segmented photodiode 608-2. The beam from collimated light source 602-2 is initially reflected by beam splitter 610-2 and, after reflection from the surface, is provided by beam splitter 610-1 to segmented photodiode 608-1. Segmented photodiodes 608-1 and 608-2 are used to measure distance, as for Figure 6 However, if the surface is tilted, the distances measured by segmented photodiodes 608-1 and 608-2 will differ. Because triangulator 700 directs beams onto the surface from opposite directions, tilt has opposite effects on the distances measured by segmented photodiodes 608-1 and 608-2. Triangulator 700 thus allows the effects of tilt to be canceled, resulting in more accurate distance measurements.

[0055] Figure 8 FIG2 is an optical diagram of a triangulator 800 that can be used as a distance measurement sensor 205 according to some embodiments. The triangulator 800 includes a collimated light source (e.g., a laser) 802, a folding (i.e., tilting) mirror 804, and an imager 806 on a top surface 810 of a teaching substrate. In some embodiments, the imager 806 is a camera or a combination of a lens and a segmented photodiode (e.g., a two-cell or four-cell photodiode). The collimated light source 802 produces a collimated light beam 808. The folding mirror 804 directs the beam 808 downward and sideways at a known angle (e.g., a tilt angle) through the teaching substrate, which can be transparent or have a hole to allow the beam 808 to pass through. The beam 808 is incident on a surface 812. The imager 806 captures an image showing the location of the beam 808 incident on the surface 812 (i.e., the location of the light point of the beam 808 on the surface 812). The distance from imager 806 to surface 812 (e.g., axial distance) is determined based on the position of the light point in the image, the field of view of imager 806, and the angle of collimated light beam 808 (as reflected by fold mirror 804) relative to the axis of imager 806. In some embodiments, imager 806 is camera 203 or 208, such that the same camera is used to capture image data and perform distance measurements. Alternatively, imager 806 is distinct from cameras 203 and 208 (e.g., such that it is used only to perform distance measurements).

[0056] In some embodiments, the triangulator used as or in the distance measurement sensor 205 is different from the triangulators 600, 700, and 800 ( Figures 6 to 8). For example, a commercially available (eg, off-the-shelf) triangulator may be used.

[0057] In some embodiments, instead of a triangulator, the distance measurement sensor 205 includes a structured light projector and a camera. The structured light projector projects a structured light pattern onto a surface in the tool 100 (e.g., in the EFEM 101), and the camera captures an image of the surface as illuminated by the structured light pattern. Based on the image and the structured light pattern, the distance to the surface and / or the surface tilt are determined.

[0058] Other examples of distance measurement sensors 205 include a pair of cameras that perform dual-camera triangulation, capacitive proximity sensors, and ultrasonic range sensors. Figure 2A 、 3 and 4) can be used as a distance measurement sensor 205 by estimating the distance traveled by the arm of the substrate handling robot 108 before it impacts a surface (e.g., a wall), where the impact is a sudden deceleration detected by the accelerometer in the IMU 206. One or more distance measurement sensors 205 can be used to generate a depth map that indicates the tilt of the mapped surface.

[0059] In some embodiments, the distance measurement sensor 205 ( Figure 2A 、 3 and 4) (e.g., triangulator 600, Figure 6 ;700, Figure 7 ; or 800, Figure 8 ) is used to measure the tilt of the surface relative to the teaching substrate. Then, the wafer handling robot 108 ( Figure 1 ) will teach the substrate and therefore position the distance measurement sensor 205 at three or more different horizontal positions above the surface. The distance measurement sensor 205 measures the distance from each position to the surface. These measurements are sufficient to define the plane of the surface and extract the tilt angles (e.g., pitch and roll) accordingly.

[0060] Figure 9 is a flow chart illustrating a method 900 for performing automatic teaching of substrate handling according to some embodiments. The method 900 may be performed by the computer 103 ( Figure 1 and 19 ) is executed. For example, when the processing or inspection tool 100 ( Figure 1 ) and after the tool 100 has been modified (e.g., after a new component that can affect the movement of the substrate 102 is installed in the tool 100).

[0061] In method 900, a method for obtaining (902) a tool 100 ( Figure 1) in the substrate handling robot 108. The data may include: nominal teaching position 904; EFEM position, specifications and limits 906; and data for teaching substrates (e.g., teaching substrate 200, Figures 2A to 2B ;300, Figure 3 ;400, Figure 4 ;500, Figures 5A to 5B ; 2000, Figures 20A to 20B ) calibration data 908. The nominal taught positions 904 may include nominal positions from which the substrate handling robot 108 will pick up substrates and place them on various workstations in the tool 100. The nominal taught positions 904 and the EFEM positions, specifications, and limits 906 may be specified according to the design of the tool 100 and may be stored in the memory 1910 ( Figure 19 ) and obtained from memory 1910. Calibration data 908 may be obtained wirelessly from the teaching substrate. Using the obtained data, an initial route for the substrate handling robot 108 is planned (910). Commands corresponding to the initial route are determined for the EFEM 101 and the teaching substrate and sent (912) to the EFEM 101 and the teaching substrate, respectively. The EFEM 101 executes (914) its commands. The teaching substrate records (914) data including sensor data according to its commands.

[0062] Data is received 916 from the teaching substrate and the EFEM 101. The received data includes sensor data from the teaching substrate. The data is analyzed 918 and the planned route is modified (ie, updated) accordingly.

[0063] A determination is made (920) as to whether automatic teaching of the current workstation is complete. If not (920-No), the method returns to step 912, where additional commands are sent to the EFEM 101 and the substrate is taught (e.g., according to the modified route). If completed (920-Yes), the taught position of the current workstation is updated (922). Once the method 900 is completed, the taught position becomes the position used by the substrate handling robot 108 during production. In some embodiments, the taught position is determined based on the coordinate axes of the substrate handling robot 108.

[0064] A determination is made (924) as to whether auto-teach is complete for all workstations. If not complete (924-No), the next workstation is selected (926) for auto-teach and the method 900 returns to step 912 where additional commands are sent to the EFEM 101 and the teach substrate. If complete (924-Yes), the teach substrate is returned (928) to the pod 104 (which is used to load the teach substrate into the EFEM 101 through the load port 105). Figure 1), and the method 900 ends. The teaching substrate (ie, the pod 104 containing the teaching substrate) can now be unloaded from the load port 105, and the tool 100 can be used for production (eg, can be used to fabricate or inspect production substrates).

[0065] Figure 10 1 is a flow chart illustrating a method 1000 for performing automatic teaching of substrate handling according to some embodiments. The method 1000 may be an example of the method 900 or a portion thereof. The method 1000 may be performed by the computer 103 ( Figure 1 and 19 )implement.

[0066] In method 1000, a teaching substrate (eg, teaching substrate 200, Figures 2A to 2B ;300, Figure 3 ;400, Figure 4 ;500, Figures 5A to 5B ; 2000, Figures 20A to 20B ) loaded (1002) into tool 100 ( Figure 1 ) in the loading port 105 of the EFEM 101. The EFEM 101 includes a substrate handling robot 108. A plurality of sensors and one or more wireless transceivers 207 ( Figure 2A 、 3 , 4) on the teaching substrate (i.e., the teaching substrate includes the plurality of sensors and one or more wireless transceivers 207). The tool 100 includes a plurality of workstations. In some embodiments, the plurality of sensors include (1004): a first camera 210 for imaging an area on one side of the teaching substrate in the EFEM; a second camera (e.g., camera 208) for imaging an area below the teaching substrate (e.g., below the center of the teaching substrate) in the EFEM; a third camera 203 for imaging an area below the edge of the teaching substrate in the equipment front end module; one or more distance measurement sensors 205 facing downward and / or sideways relative to the teaching substrate; an IMU 206; and / or one or more accelerometers (which may be part of the IMU 206). In some embodiments, a pod 104 containing the teaching substrate is loaded into a loading port 105. The teaching substrate is oriented in the pod 104 so that the corresponding sensor (e.g., first camera 210) faces the desired direction.

[0067] With the taught substrate in the EFEM 101, the substrate handling robot 108 moves along an initial route (1006). The initial route may be the initial route planned in step 910 of method 900, and the substrate handling robot 108 may move along an initial route in response to step 912 of method 900 ( Figure 9 ) and moves along the initial route.

[0068] With the teaching substrate located in the EFEM 101, sensor data is wirelessly received (1008) from the teaching substrate (e.g., as in step 916 of method 900). Figure 9 In some embodiments, the sensor data includes one or more images captured by the first camera 210, one or more images captured by the second camera (e.g., camera 208), one or more images captured by the third camera 203, one or more distances (e.g., axial distances from a surface below the teaching substrate) determined by the distance measurement sensor 205 (e.g., distances from objects next to the teaching substrate), data from the IMU 206 (e.g., motion measurements), and / or data from one or more accelerometers (e.g., acceleration measurements). The motion measurements may include acceleration measurements or a portion thereof. Once the substrate handling robot 108 has reached a specified location and / or if the substrate handling robot 108 is at a plurality of specified locations, the sensor data may be acquired as the substrate handling robot 108 moves along the initial route.

[0069] Based at least in part on the sensor data, a modified route is determined (1010) (e.g., as in step 918 of method 900, Figure 9 The modified route is different from the initial route. The substrate handling robot 108 moves along the modified route (1012) (e.g., in response to the command sent in the iteration of step 912 of method 900, Figure 9 ). Moving the substrate transport robot 108 includes transporting the teaching substrate with the substrate transport robot 108. For example, moving the substrate transport robot 108 includes picking up the teaching substrate using the end effector 109 and / or moving the teaching substrate as loaded on the end effector 109.

[0070] Based at least in part on the sensor data, determining (1014) the locations of the plurality of workstations (e.g., according to step 922 of method 900, Figure 9 ). In some embodiments, the determined positions include taught positions of the substrate handling robot 108, which the substrate handling robot 108 will use during production to deliver production substrates to and retrieve production substrates from respective ones of the plurality of workstations. In some embodiments, the positions are determined according to coordinate axes of the substrate handling robot 108. A production route through the EFEM 101 is determined (1016) based at least in part on the determined positions of the plurality of workstations. For example, the production route may be determined based on the determined positions and sensor data (e.g., sensor data indicating the location of an obstacle in the tool 100). In some embodiments, the positions and the production route are stored in the memory 1910 ( Figure 19 )middle.

[0071] The teaching substrate may be rotated one or more times during method 1000 using the pre-aligner 106 to achieve the desired positioning of the sensor on the teaching substrate and thereby allow the desired sensor data to be obtained.

[0072] In some embodiments, steps 1006, 1008, 1010, 1012, 1014, and / or 1016 are performed automatically without intervention by a user (e.g., a technician or operator). Automating these steps speeds up the teaching process, thereby reducing system downtime and increasing throughput. Automating these steps also increases teaching accuracy because human error is eliminated.

[0073] The teach substrate is unloaded 1018 from the EFEM 101. After the teach substrate has been unloaded, a production substrate is loaded 1020 into the EFEM 101 and moved along a production route through the EFEM 101 using the substrate handling robot 108. For example, the production substrate is picked up using the end effector 109 and moved from workstation to workstation by the substrate handling robot 108.

[0074] Figure 10 Several operations are shown that appear to occur in a particular order. However, method 1000 may include more or fewer operations. Two or more operations may be combined into a single operation. Non-sequence-dependent operations may be performed in a different order than shown and / or may overlap. For example, steps 1006 and 1008 may overlap. In another example, steps 1006, 1008, 1010, 1012, 1014, and / or 1016 may be performed repeatedly. Other examples are possible.

[0075] Figure 11 is a diagram showing the execution load port 105 ( Figure 1 ) in a flow chart of a method 1100 for automatically teaching substrate handling. The method 1100 may be a flowchart of the method 900 ( Figure 9 ) and / or method 1000( Figure 10 ). Method 1100 may be performed by computer 103 ( Figure 1 and 19 )implement.

[0076] In method 1100, a pod 104 is loaded (1102) onto a loading port 105 of an EFEM 101 ( Figure 1 ). The pod 104 contains a teaching substrate (e.g., a teaching substrate 200, Figures 2A to 2B ;300, Figure 3 ;400, Figure 4 ;500, Figures 5A to 5B ; 2000, Figures 20A to 20B ) and target fixture 1208 ( Figure 12 ). The target fixture 1208 is aligned with the coordinates of the pod 104; for example, the target fixture 1208 indicates a center position in the pod 104 and may also include other markings (e.g., radial markings). The teaching substrate has multiple sensors. The teaching substrates are oriented and sufficiently separated in the pod 104 to allow imaging of the target fixture 1208 (e.g., as described below for step 1106). For example, the target fixture 1208 is in the first slot of the pod 104 and the teaching substrate is in the last slot of the pod 104. Loading 1102 the pod 104 into the load port 105 may be a step in the method 1000 of loading the teaching substrate 1002, Figure 10 ) to the instance in the loading port.

[0077] The end effector 109 of the substrate handling robot 108 in the EFEM 101 is inserted (1104) into the pod 104 (e.g., loaded into the load port 105). Inserting the end effector 109 into the pod 104 may be to move the substrate handling robot 108 along the initial path (1006, Figure 10 ). The end effector 109 can be inserted into the substrate pod between the target fixture 1208 and the teaching substrate, with the bottom surface of the teaching substrate facing the end effector 109.

[0078] The plurality of sensors include cameras (eg, cameras 203 or 208, Figures 2A to 5B ) to image the area beneath the teaching substrate in the EFEM 101. Sensor data is wirelessly received (1106) from the teaching substrate, the sensor data including an image 1200 taken by a camera showing the end effector 109 and a target fixture 1208. Figure 12 An example of image 1200 is shown in which tines 1202 and 1204 of end effector 109 are visible above target fixture 1208. According to some embodiments, tines 1202 and 1204 have vacuum pads 1206 that will be used to pick up a teaching substrate. Image 1200 can be analyzed to determine the angular offset between end effector 109 and the teaching substrate in pod 104 (e.g., in the coordinate system provided by target fixture 1208). Image 1200 can also be analyzed to determine the eccentricity of end effector 109 relative to the teaching substrate and pod 104 (i.e., how off-center end effector 109 is). For example, the location of scribe line 1210 on tines 1202 and 1204 is used to determine the eccentricity of end effector 109 relative to a camera, whose offset in the coordinate system of the teaching substrate is known, and then relative to the teaching substrate.

[0079] The substrate handling robot 108 raises (1108) the end effector 109 toward the teaching substrate. In some embodiments, raising the end effector 109 includes moving the end effector 109 along a route determined at least in part based on the image 1200 (1110): the image 1200 or multiple images including the image 1200 can be used to guide the end effector 109 upward toward the teaching substrate. Raising the end effector 109 can be causing the substrate handling robot 108 to move along the modified route (1012, Figure 10 ) an instance or portion of ).

[0080] The plurality of sensors further include a distance measurement sensor 205 ( Figure 2A 、 3 , 4 and 20A-20B). Sensor data is wirelessly received (1112) from the teaching substrate, the sensor data including the distance of the end effector 109 from the teaching substrate measured by the distance measurement sensor 205 after the end effector 109 is raised toward the teaching substrate.

[0081] The position of the teaching substrate in the pod 104 as loaded into the load port 105 is determined 1114 as the position of the end effector 109 in the pod 104. These determinations are made at least in part based on the image 1200 and the distance of the end effector 109 from the teaching substrate (i.e., the distance measured in step 1112), and may be further based at least in part on other sensor data from the teaching substrate (e.g., other images, data from the IMU 206, etc.) and the known placement of the target fixture 1208 and the teaching substrate in the pod 104. For example, the image 1200 is used to determine the x- and y-positions of the teaching substrate relative to the target fixture 1208; the image 1200 is used to determine the angle between the end effector 109 and the target fixture 1208; the eccentricity of the end effector 109 is determined using the scribe line 1210 as shown in the image 1200; and the z-position of the teaching substrate is determined using the distance measured in step 1112. Determining this location may be determined in method 1000 (1014, Figure 10 ) is part of a plurality of workstations, the pod 104 in the load port 105 being one of the workstations. The teaching substrate can be picked up (ie, loaded onto the end effector 109) from its determined position.

[0082] Figure 13 1 is a flow chart illustrating a method 1300 for performing automatic teaching of substrate handling for a pre-aligner 106 according to some embodiments. The pre-aligner 106 is a tool 100 ( Figure 1 ) in one of the workstations. Method 1300 may be method 900 ( Figure 9 ) and / or method 1000( Figure 10 ). Method 1300 may be performed by computer 103 ( Figure 1 and 19 )implement.

[0083] In method 1300, based on the known nominal position of the pre-aligner 106, a teaching substrate (e.g., teaching substrate 200, Figures 2A to 2B ;300, Figure 3 ;400, Figure 4 ;500, Figures 5A to 5B ; 2000, Figures 20A to 20B ) carries (1302) the teaching substrate toward the pre-aligner 106. For example, the teaching substrate is carried to a "ready position" at the side of the pre-aligner 106. Carrying (1302) the teaching substrate toward the pre-aligner 106 may be moving the substrate handling robot 108 along the initial route (1006, Figure 10 ) an instance or portion of ).

[0084] The teaching substrate has a plurality of sensors including a first camera 210 ( Figures 2A to 5B ) and a second camera (e.g., camera 203 or 208, ) for imaging the area beneath the teaching substrate in the EFEM 101. Figures 2A to 5B ). Sensor data is wirelessly received (1304) from the teaching substrate, the sensor data comprising a side image 1400 (e.g., from a prepared position to the side of the pre-aligner 106) of the pre-aligner 106 taken by the first camera 210. Figure 14A ). The pre-aligner 106 is identified in the side image 1400 using object recognition (e.g., a trained machine learning model). In some embodiments, the substrate handling robot 108 moves upward and / or downward to position the top of the pre-aligner 106 in the middle of the side image 1400, thereby eliminating the height of the pre-aligner 106. The distance to the pre-aligner 106 (e.g., from the prepared position to the pre-aligner 106) can be estimated based on the width of the pre-aligner 106 in the image 1400.

[0085] After the first camera 210 has captured the side image 1400 of the prealigner 106, the substrate handling robot 108 moves the teaching substrate over the prealigner 106 (1306) (e.g., using the estimated height of and distance from the prealigner 106). The substrate handling robot 108 may move the end effector 109 over the prealigner 106 along a route determined at least in part based on the side image 1400 of the prealigner 106 (1308). Moving the teaching substrate over the prealigner 106 may be moving the substrate handling robot 108 along a modified route (1012, Figure 10 ) an instance or portion of ).

[0086] In some embodiments, the substrate handling robot 108 moves 1310 the teach substrate to a plurality of sequential positions above the pre-aligner 106 to determine the coordinate axes of the substrate handling robot 108 relative to the pre-aligner 106 .

[0087] Sensor data is wirelessly received (1312) from the teaching substrate, the sensor data including data acquired by a second camera (e.g., camera 203 or 208, Figures 2A to 5B ) of the top image 1420 of the pre-aligner 106 ( Figure 14B ). The second camera captures a top image 1420 with the taught substrate positioned above the pre-aligner 106. In some embodiments, respective top images of the pre-aligner 106 captured by the second camera from respective ones of the plurality of positions (e.g., from each position) are wirelessly received 1314.

[0088] The plurality of sensors further include a distance measurement sensor 205 ( Figure 2A 、 3 , 4, and 20A-20B). Sensor data is wirelessly received 1316 from the teaching substrate, the sensor data including the distance from the teaching substrate to the pre-aligner 106 (e.g., the axial distance from the pre-aligner 106). This distance is determined by the distance measurement sensor 205 when the teaching substrate is located above the pre-aligner 106. The wafer handling robot 108 may lower the teaching substrate toward the pre-aligner 106 before the distance measurement sensor 205 measures this distance.

[0089] The position of the pre-aligner 106 (e.g., the position of the innermost vacuum pad 1422 of the pre-aligner, e.g., the position of the innermost vacuum pad 1422 of the pre-aligner) is identified (1318) based at least in part on the top image 1420 and / or the distance from the teaching substrate to the pre-aligner 106. Figure 14B ). For example, object recognition (eg, a trained machine learning model) is used (eg, in addition to the distance measurement data) to identify the location of the pre-aligner 106 in the top image 1420.

[0090] In some embodiments, the image is generated based at least in part on corresponding top images taken from multiple locations (including top image 1420, Figure 14B ) and / or the distance from the teach substrate to the pre-aligner 106 to identify (1320) the position of the pre-aligner 106. The computer 103 knows the movement reach of the wafer handling robot 108 to each of the plurality of positions: this movement occurs in response to commands from the computer 103 and can also be measured by the IMU 206. The computer 103 can identify the position of the pre-aligner 106 in each of the corresponding top images. This information (e.g., in addition to the distance measurement data) is used to identify the position of the pre-aligner 106. Identifying the position of the pre-aligner 106 can be determined in method 1000 (1014, Figure 1 ) is part of a location where multiple workstations are located.

[0091] Figure 15 is a diagram illustrating an implementation of a chuck 1700 according to some embodiments. Figure 17 ) is a flowchart of a method 1500 for automatically teaching. ( Figure 17 is a plan view of a chuck 1700 according to some embodiments. )Chuck 1700 is a workstation 107 ( Figure 1 ), workstation 107 is part of tool 100 ( Figure 1 ) in one of the workstations in the chuck. The chuck 1700 is shown having a slot 1702 to receive the end effector 109 (e.g., to receive the corresponding tines 1202 and 1204, Figure 12 Alternatively, the chuck 1700 may use lift pins or some other mechanism to receive the substrate. The chuck 1700 is thus located in the tool cavity 111 ( Figure 1 ) and may be referred to as a tool chuck. Method 1500 may be method 900 ( Figure 9 ) and / or method 1000( Figure 10 ). Method 1500 may be performed by computer 103 ( Figure 1 and 19 )implement.

[0092] In method 1500, a substrate handling robot 108 in an EFEM 101 has (1502) an end effector 109 for carrying a substrate. A tool chamber 111 in which a chuck 1700 is positioned is opened through a hatch 110 ( Figure 1 ) is separated from the EFEM 101. The teaching substrate (eg, the teaching substrate 200, Figures 2A to 2B ;300, Figure 3 ;400, Figure 4 ;500, Figures 5A to 5B ; 2000, Figures 20A to 20B) has multiple sensors including a first camera 210 to image an area on one side of the teaching substrate in the EFEM, a second camera 208 to image an area under the center of the teaching substrate, and / or a third camera (e.g., camera 203, Figures 2A to 5B ;Camera 2002, Figures 20A to 20B ).

[0093] With the teach substrate positioned on the end effector 109, the substrate handling robot 108 positions (1504) the teach substrate in front of the hatch 110 so that the hatch 110 is within the field of view 502 ( Figures 5A to 5B This positioning enables the substrate handling robot 108 to move along the initial route (1006, Figure 10 ) an instance or portion of ).

[0094] Sensor data including an image of the hatch 110 is wirelessly received (1506) from the teaching substrate. An image of the hatch 110 is taken by the first camera 210 with the teaching substrate positioned in front of the hatch 110. The computer 103 can use this image to determine the position of the hatch 110. In some embodiments, the substrate handling robot 108 uses the first camera 210 to scan along the edge of the hatch 110, or scan up and down and left and right in front of the hatch 110, thereby generating a series of images of the hatch 110. The computer 103 wirelessly receives these images and uses the images to determine the position of the hatch 110 (e.g., the center of the hatch 110). In some embodiments, the sensor data includes distance measurements obtained using the distance measurement sensor 205, which the computer 103 uses to determine the tilt between the teaching substrate and the hatch 110.

[0095] In some embodiments, the teaching substrate is repositioned (1508) in front of the hatch 110 to allow the third camera (e.g., camera 203, Figures 2A to 5B ) facing the hatch 110. For example, the substrate handling robot 108 returns the teaching substrate to the pre-aligner 106, which rotates the teaching substrate. The substrate handling robot 108 then picks up the rotated teaching substrate from the pre-aligner 106 and returns the teaching substrate to a position in front of the hatch 110, with the third camera facing the hatch 110. If the third camera is on the same side of the teaching substrate as the first camera 210 (e.g., if the third camera is camera 2002, Figures 20A to 20B ), then step 1508 can be omitted.

[0096] After this repositioning, the teaching substrate is inserted (1510) into the tool chamber 111 (now positioned) through the hatch 110 with the teaching substrate positioned on the chuck 1700. Steps 1508 and 1510 may be to move the substrate handling robot 108 along the modified route (1012, Figure 10 ) an instance or portion of ).

[0097] Sensor data is wirelessly received (1512) from the teaching substrate, the sensor data including an image of the chuck 1700 taken by the third camera with the teaching substrate positioned over the chuck 1700. The position of the chuck 1700 is identified (1514) based at least in part on this image of the chuck 1700. For example, a boundary of the chuck 1700, or a portion of the boundary, is identified in the image, and a center of the chuck 1700 is identified based on a curvature of the boundary or portion thereof. The orientation of the chuck 1700 may be determined based on the orientation of the slot 1702 in the image. If the chuck 1700 uses lift pins instead of the slots 1702, the orientation of the chuck 1700 may be determined based on the position of all or a portion of the lift pins in the image (e.g., based on the position of at least two of the lift pins). Identifying the position of the chuck 1700 may be a step of determining (1014, Figure 1 ) is part of a location where multiple workstations are located.

[0098] Figure 16 is a diagram illustrating an implementation of a chuck 1700 according to some embodiments. Figure 17 ) is a flowchart of a method 1600 for automatically teaching. The method 1600 is a flowchart of a method 1500 ( Figure 15 ). Method 1600 may be an alternative to method 900 ( Figure 9 ) and / or method 1000( Figure 10 ). Method 1600 may be performed by computer 103 ( Figure 1 and 19 )implement.

[0099] In method 1600, a substrate handling robot 108 in an EFEM 101 has (1602) an end effector 109 for carrying a substrate. A chuck 1700 is disposed in a tool chamber 111 separated from the EFEM 101 by a hatch 110. A teaching substrate (e.g., teaching substrate 200, Figures 2A to 2B ;300, Figure 3 ;400, Figure 4 ;500, Figures 5A to 5B ; 2000, Figures 20A to 20B) has a plurality of sensors including a first camera 210 for imaging an area on one side of the teaching substrate in the EFEM 101 and a distance measurement sensor 205 facing sideways relative to the teaching substrate.

[0100] With the teach substrate positioned on the end effector 109, the substrate handling robot 108 positions (1504) the teach substrate in front of the hatch 110 so that the hatch 110 is within the field of view 502 ( Figures 5A to 5B ). This positioning can be to move the substrate handling robot along the initial route (1006, Figure 10 ) an instance or portion of ).

[0101] Sensor data is wirelessly received (1506) from the teaching substrate, the sensor data including an image of the hatch 110. The image of the hatch 110 is captured by the first camera 210 with the teaching substrate positioned in front of the hatch 110. As in method 1500 ( Figure 15 ), the computer 103 may use this image (eg, using a series of images resulting from scanning the hatch 110 , including this image) to determine the location of the hatch 110 .

[0102] In some embodiments, the teaching substrate is repositioned (1608) in front of the hatch 110 so that the distance measurement sensor 205 faces the hatch 110. For example, the substrate handling robot 108 returns the teaching substrate to the pre-aligner 106, which rotates the teaching substrate. The substrate handling robot 108 then picks up the rotated teaching substrate from the pre-aligner 106 and returns the teaching substrate to a position in front of the hatch 110 with the distance measurement sensor 205 facing the hatch 110. If the distance measurement sensor 205 is immediately adjacent to the first camera 210, step 1608 can be omitted.

[0103] After this repositioning, the teach substrate is inserted (1610) into the tool chamber 111 through the hatch. Steps 1608 and 1610 may be steps of moving the substrate handling robot 108 along the modified route (1012, Figure 10 ). In the case where the teaching substrate is inserted into the tool chamber 111 , the distance measurement sensor 205 scans the side of the chuck 1700 .

[0104] Sensor data is wirelessly received (1612) from the teaching substrate, the sensor data including distance measurements obtained by the distance measurement sensor 205 when scanning the side of the chuck 1700. The position of the chuck 1700 is identified (1614) based at least in part on the distance measurements. For example, the distance measurements indicate the curvature of the side of the chuck 1700 and thus allow the position of the center of the chuck 1700 to be calculated because the shape of the chuck 1700 is known (e.g., circular). Identifying the position of the chuck 1700 can be determined (1014, Figure 1 ) is part of a location where multiple workstations are located.

[0105] In some embodiments, identifying the position of the chuck 1700 includes identifying 1616 the position of the slot 1702 based at least in part on the distance measurement. Scanning the side of the chuck 1700 with the distance measurement sensor 205 reveals the position of the slot 1702 by finding where the measured distance suddenly increases or decreases.

[0106] Figure 18 is a teaching substrate according to some embodiments (eg, teaching substrate 200, Figures 2A to 2B ;300, Figure 3 ;400, Figure 4 ;500, Figures 5A to 5B ; 2000, Figures 20A to 20B ) is a block diagram of an electronic component 1800. The electronic component 1800 includes one or more processors 1802 (eg, CPU; microcontroller), one or more wireless transceivers 207 ( Figure 2A 、 3 and 4), sensors 1808, lighting devices 1820, memory 1830, and one or more communication buses 1804 that interconnect these components. The one or more communication buses 1804 can be implemented using one or more circuit boards on the teaching substrate (e.g., on the top surface of the teaching substrate). The wireless transceiver 207 allows the teaching substrate to communicate with the computer 103 ( Figure 1 and 19 ) and / or other remote computer systems. In some embodiments, the wireless transceiver 207 includes a WLAN (e.g., WiFi) and / or a PAN (e.g., Bluetooth) transceiver.

[0107] In some embodiments, the sensor 1808 includes one or more cameras 1810 (e.g., cameras 203, 208, and / or 210, Figures 2A to 5B ), one or more distance measuring sensors 205 ( Figure 2A 、 3 and 4) (e.g., triangulator 600, Figure 6 ;700, Figure 7 ; or 800, Figure 8)、IMU 206( Figure 2A 、 3 and 4) and / or one or more accelerometers 1816. Accelerometer 1816 can be part of IMU 206. In some embodiments, lighting device 1820 includes one or more light guide panels 1822 (e.g., panels 204 and / or 209, Figures 2A to 2B ; Panels 302, 304 and / or 306, Figure 3 ) and / or LED 1824 (e.g., LED 402 and / or 404, Figure 4 ).

[0108] Memory 1830 includes volatile and / or nonvolatile memory. Memory 1830 (e.g., nonvolatile memory within memory 1830) includes non-transitory computer-readable storage media. All or a portion of memory 1830 (e.g., nonvolatile memory within memory 1830) may be embedded in processor 1802. For example, memory 1830 may include nonvolatile memory embedded in a microcontroller. Memory 1830 optionally includes one or more storage devices located remotely from processor 1802. In some embodiments, the memory 1830 (e.g., a transitory computer-readable storage medium of the memory 1830) stores the following modules and data, or a subset or superset thereof: an operating system 1832 for handling various basic system services and for performing hardware-dependent tasks; a sensor calibration module 1834 for calibrating the sensors 1808 and storing the resulting calibration data; a sensor control module 1836 for controlling the sensors 1808; a lighting control module 1838 for controlling the lighting devices 1820; and a communication module 1840 for controlling wireless communications with the computer 103 and / or other remote computer systems (e.g., communications performed using one or more wireless transceivers 207). In some embodiments, the sensor control module 1836 turns the corresponding sensor 1808 on and off, reads sensor data, compresses sensor data, stores sensor data in the memory 1830 (e.g., if communication with the computer 103 fails), reads the status of the corresponding sensor 1808, and / or checks whether the battery status is sufficient to operate the sensor 1808. The communication module 1840 can send calibration and sensor data to the computer 103 and receive commands from the computer 103. In some embodiments, the sensor calibration module 1834, the sensor control module 1836, and the lighting control module 1838 execute commands received from the computer 103 wirelessly.

[0109] Memory 1830 (e.g., a non-transitory computer-readable storage medium of memory 1830) thus includes instructions for implementing the functionality of the teaching substrate. Each of the modules stored in memory 1830 corresponds to a set of instructions for performing one or more functions described herein. Individual modules need not be implemented as separate software programs. Modules and various subsets of modules may be combined or otherwise rearranged. In some embodiments, memory 1830 stores a subset or superset of the modules identified above.

[0110] Figure 18 It is intended more as a functional illustration of the various features that may be present on the teaching substrate than as a block diagram. For example, alternatively, a portion of the modules stored in the memory 1830 may be stored in one or more computer systems that are wirelessly communicatively coupled to the teaching substrate via one or more networks.

[0111] Figure 19 is a computer 103 ( Figure 1 ) is a block diagram of a computer 103 communicatively coupled to a fabrication or inspection tool 100 ( Figure 1 ); in some embodiments, the computer 103 is part of the tool 100. The computer 103 includes one or more processors 1902 (e.g., CPUs), one or more wireless transceivers 1906, memory 1910, and one or more communication buses 1904 that interconnect these components. In some embodiments, the one or more communication buses 1904 interconnect these components with the tool 100. In some other embodiments, the computer 103 also includes a wired network interface, which the computer uses to communicate with the tool 100 over one or more wired networks. In still other embodiments, the computer 103 communicates with the tool 100 wirelessly using the wireless transceiver 1906. In some embodiments, the wireless transceiver 1906 includes a WLAN (e.g., WiFi) and / or a PAN (e.g., Bluetooth) transceiver.

[0112] The computer 103 may include one or more user interfaces (not shown), such as a display and one or more input devices (e.g., a keyboard of the display, a mouse, a touch-sensitive surface, etc.). The display may show sensor data (e.g., images) received from the teaching substrate in the tool 100 and may report the status of the methods described herein.

[0113] Memory 1910 includes volatile and / or nonvolatile memory. Memory 1910 (e.g., nonvolatile memory within memory 1910) includes non-transitory computer-readable storage media. Memory 1910 optionally includes one or more storage devices located remotely from processor 1902 and / or non-transitory computer-readable storage media removably inserted into computer 103. In some embodiments, memory 1910 (e.g., non-transitory computer-readable storage media of memory 1910) stores the following modules and data, or a subset or superset thereof: an operating system 1912 including process steps for handling various basic system services and for performing hardware-dependent tasks; a processor for controlling EFEM 101 (e.g., including load port 105, wafer handling robot 108, pre-aligner 106, and hatch 110); Figure 1 ) ; a tool chamber control module 1916 for controlling the tool chamber 111 (e.g., for controlling substrate fabrication or inspection performed in the tool chamber 111); and an auto-teach module 1918 for controlling the performance of an auto-teach process for substrate handling. In some embodiments, the auto-teach module 1918 includes: a teach substrate command module 1920 for determining commands for a teach substrate and sending the commands to the teach substrate; a position determination module 1922 for determining the position of a workstation in the tool 100; a route determination module 1924 for determining a route for the substrate handling robot 108 and for substrates handled by the substrate handling robot 108; and data 1926 (e.g., data 904, 906, and / or 908 of method 900, Figure 9 ; sensor data received from the teaching substrate).

[0114] Memory 1910 (eg, a non-transitory computer-readable storage medium of memory 1910 ) (eg, auto-teaching module 1918 and / or EFEM control module 1914 ) includes instructions for executing method 900 ( Figure 9 )、1000( Figure 10 )、1100( Figure 11 )、1300( Figure 13 )、1500( Figure 15 ) and / or 1600( Figure 16 ) instructions for all or part of the modules described herein. Each of the modules stored in memory 1910 corresponds to a set of instructions for performing one or more functions described herein. Individual modules need not be implemented as separate software programs. Modules and various subsets of modules may be combined or otherwise rearranged. In some embodiments, memory 1910 stores a subset or superset of the modules and data structures identified above.

[0115] Figure 19It is intended more as a functional illustration of various features that may be present in computer 103 than as a schematic diagram. For example, the functionality of computer 103 may be split among multiple devices. Alternatively, a portion of the modules stored in memory 1910 may be stored in one or more other computer systems communicatively coupled to computer 103 via one or more networks.

[0116] The methods and hardware described herein allow for rapid and accurate teaching of the substrate handling robot 108. For example, the teaching can be fully automated so that intervention by a technician (e.g., other than loading the pod 104 into the load port 105) is avoided and human error is eliminated. No data other than the data stored in the computer 103 (e.g., data 904, 906, and 906 of method 900) may be used. Figure 9 ) to perform teaching. Teaching can be performed without installing additional hardware (e.g., sensors) in the tool 100 for the teaching process.

[0117] For purposes of illustration, the foregoing description has been described with reference to specific embodiments. However, the above illustrative discussions are not intended to be exhaustive or to limit the scope of the claims to the precise forms disclosed. Many modifications and variations are possible in light of the above teachings. The embodiments are selected to best illustrate the principles underlying the claims and their practical application, thereby enabling those skilled in the art to best utilize the embodiments with various modifications as appropriate for the particular application contemplated.

Claims

1. A device comprising: a substrate to be loaded into an equipment front end module of a fabrication or inspection tool, wherein the substrate is carried by an end effector of a substrate handling robot of the equipment front end module, and wherein the tool includes a plurality of workstations, and the plurality of workstations include chucks located in a chamber of the tool different from the equipment front end module, the chamber being separated from the equipment front end module by a hatch; a first camera positioned on the substrate to image an area facing outward from one side of the substrate; a second camera positioned on the substrate to image an area beneath the substrate; and one or more wireless transceivers located on the substrate to transmit images captured by the first camera and the second camera, wherein the substrate is positioned in front of the hatch with the substrate on the end effector so that the hatch is in a field of view of the first camera, and wherein the image includes an image of the hatch captured by the first camera; Wherein an initial route for moving the substrate in the tool by the substrate handling robot is modified based at least in part on the images captured by the first camera and the second camera to determine a modified route for moving the substrate in the tool.

2. The apparatus according to claim 1, wherein: The second camera is positioned on the substrate to image an area below the center of the substrate; and The apparatus further includes a third camera positioned above the substrate to image an area below an edge of the substrate; The one or more wireless transceivers are to transmit images captured by the third camera. 3 . The apparatus of claim 2 , further comprising a fourth camera positioned on the substrate to image an area beneath the first camera.

4. The apparatus of claim 3 , wherein the third camera and the fourth camera face sideways relative to the substrate, the apparatus further comprising: a first mirror to direct the field of view of the third camera to the area below the edge of the substrate; and A second mirror is configured to direct the field of view of the fourth camera to the area below the first camera.

5. The apparatus according to claim 2, wherein: The manufacturing or inspection tool is a tool for manufacturing or inspecting semiconductor wafers; The substrate is in the shape of a wafer; The first camera, the second camera, and the third camera are positioned along a diameter of the substrate; and The third camera and the first camera are located on opposite sides of the second camera along the diameter.

6. The apparatus of claim 2, wherein: The first camera, the second camera, and the third camera are located on top of the substrate; the first camera faces sideways relative to the substrate; The second camera and the third camera face downward relative to the substrate; and The substrate is transparent.

7. The apparatus according to claim 2, wherein: The first camera, the second camera, and the third camera are located on top of the substrate; the first camera faces sideways relative to the substrate; the second camera faces sideways relative to the substrate; and The apparatus further includes a mirror to direct the field of view of the second camera to the area below the center of the substrate.

8. The apparatus of claim 2, wherein: The first camera, the second camera, and the third camera are located on top of the substrate; the first camera faces sideways relative to the substrate; The second camera and the third camera face downward relative to the substrate; and The substrate has a first aperture to provide the second camera with a field of view of the area below the center of the substrate and a second aperture to provide the third camera with a field of view of the area below the edge of the substrate.

9. The apparatus of claim 2, further comprising lighting apparatus for the first camera, the second camera, and the third camera.

10. The apparatus of claim 9 , wherein the illumination apparatus comprises a first light guide panel facing downward relative to the substrate to illuminate the area below the center of the substrate for imaging by the second camera and to illuminate the area below the edge of the substrate for imaging by the third camera.

11. The apparatus of claim 10, wherein the illumination apparatus further comprises a second light guide panel facing sideways relative to the substrate to illuminate the area on the one side of the substrate for imaging by the first camera.

12. The apparatus of claim 9, wherein the lighting device comprises: a first plurality of light emitting diodes (LEDs) facing downward relative to the substrate to illuminate the area below the center of the substrate for imaging by the second camera and below the edge of the substrate for imaging by the third camera; and A second plurality of LEDs faces sideways relative to the substrate to illuminate the area on the side of the substrate for imaging by the first camera.

13. The apparatus of claim 1 , further comprising a distance measurement sensor facing downward relative to the substrate to measure a distance from a surface below the substrate; The one or more wireless transceivers are to transmit data from the distance measurement sensor, the data including the distance. The device of claim 13 , wherein the distance measuring sensor comprises a triangulator.

15. The apparatus of claim 14, wherein the triangulator comprises: a collimated light source for generating a collimated beam; a lens for focusing the collimated beam; a mirror for folding the collimated beam and reflecting the collimated beam; a pair of segmented photodiodes for receiving the reflection of the collimated beam; and A pair of beam splitters is configured to provide the collimated beam to the lens and to provide the reflection of the collimated beam to the pair of segmented photodiodes, wherein the lens is configured to direct the reflection of the collimated beam to the pair of beam splitters.

16. The apparatus of claim 14, wherein the triangulator comprises: a collimated light source for generating a collimated beam; a folding mirror to direct the collimated beam downward through the substrate at an oblique angle; and An imager is configured to detect a position on the surface where the collimated beam directed downward at the tilt angle by the folding mirror is incident.

17. The apparatus of claim 1 , further comprising a distance measurement sensor facing sideways relative to the substrate to measure a distance from a surface beside the substrate; The one or more wireless transceivers transmit data from the distance measurement sensor.

18. The apparatus of claim 1, further comprising an accelerometer, wherein the one or more wireless transceivers are to transmit data from the accelerometer.

19. The apparatus of claim 1, wherein the substrate is reticle-shaped.

20. The apparatus of claim 1, wherein the one or more wireless transceivers comprise a wireless local area network (WLAN) transceiver.

21. The apparatus of claim 1, wherein the one or more wireless transceivers comprise a personal area network (PAN) transceiver.

22. A method comprising: The teach substrate is loaded into a load port of an equipment front end module of a fabrication or inspection tool, wherein: The equipment front-end module includes a substrate handling robot, and the substrate handling robot includes an end effector for carrying a substrate. The teaching substrate includes a plurality of sensors and one or more wireless transceivers, the plurality of sensors including a first camera for imaging an area outward from a side of the teaching substrate and a second camera for imaging an area below the teaching substrate, The tool includes a plurality of workstations, and the plurality of workstations including a chuck located in a chamber distinct from the tool in the equipment front end module, the chamber being separated from the equipment front end module by a hatch; With the teaching substrate positioned in the equipment front end module, moving the substrate handling robot along an initial route in the tool, comprising: positioning the teaching substrate in front of the hatch so that the hatch is in a field of view of the first camera with the teaching substrate positioned on the end effector; wirelessly receiving sensor data from the teaching substrate with the teaching substrate positioned in the equipment front end module, the sensor data comprising: an image of the hatch captured by the first camera with the teaching substrate positioned in front of the hatch, and an image captured with the second camera; determining a modified route for moving the teach substrate in the tool by the substrate handling robot based at least in part on the sensor data, wherein the modified route is different from the initial route; moving the substrate handling robot along the modified route, including handling the teaching substrate with the substrate handling robot; and Based at least in part on the sensor data, positions of the plurality of workstations are determined.

23. The method of claim 22, further comprising: determining a production route through the equipment front end module based at least in part on the determined positions of the plurality of workstations; unloading the teaching substrate from the equipment front end module; and After unloading the teaching substrate: loading a production substrate into the equipment front end module; and The production substrate is moved along the production route through the equipment front-end module using the substrate handling robot.

24. A method according to claim 22, wherein the following are automatically performed without user intervention: moving the substrate handling robot along the initial route; wirelessly receiving the sensor data from the teaching substrate; determining the modified route; moving the substrate handling robot along the modified route; and determining the positions of the multiple workstations.

25. The method of claim 22, wherein: the second camera being positioned on the teaching substrate to image an area below a center of the teaching substrate; The plurality of sensors further includes a third camera to image an area below an edge of the teaching substrate; and The sensor data further includes images captured with the third camera.

26. The method of claim 25, wherein: The plurality of sensors further includes a fourth camera to image an area below the first camera; and The sensor data further includes images captured with the fourth camera.

27. The method of claim 22, wherein: The plurality of sensors further includes a distance measurement sensor facing downward relative to the teaching substrate; and The sensor data further includes a distance to a surface underlying the teaching substrate as determined by the distance measurement sensor.

28. The method of claim 22, wherein: The plurality of sensors further includes a distance measurement sensor facing sideways relative to the teaching substrate; and The sensor data further includes a distance to an object adjacent to the teaching substrate as determined by the distance measurement sensor.

29. The method of claim 22, wherein: The plurality of sensors further comprises an accelerometer; and The sensor data further includes data from the accelerometer.

30. The method of claim 22, wherein: Loading the teaching substrate into the load port includes loading a substrate pod into the load port, the substrate pod containing the teaching substrate and a target fixture; moving the substrate handling robot along the initial route includes inserting the end effector into the substrate pod; and The sensor data includes images captured by the second camera showing the end effector and the target fixture.

31. The method of claim 30, wherein: moving the substrate handling robot along the modified route includes raising the end effector toward the teach substrate; The plurality of sensors further includes a distance measurement sensor; The sensor data further includes a distance of the end effector from the teaching substrate measured by the distance measurement sensor after raising the end effector toward the teaching substrate; and Determining the positions of the plurality of workstations includes determining a positioning of the teaching substrate in the substrate pod based at least in part on the distance of the end effector from the teaching substrate.

32. The method of claim 22, wherein: The plurality of workstations includes a pre-aligner; moving the substrate handling robot along the initial route includes carrying the teaching substrate toward the pre-aligner with the teaching substrate positioned on the end effector; The sensor data includes a side image of the pre-aligner captured by the first camera; moving the substrate handling robot along the modified route includes moving the teaching substrate over the pre-aligner after the first camera has captured the side image of the pre-aligner; and The sensor data further includes a top image of the pre-aligner taken by the second camera with the teaching substrate positioned above the pre-aligner.

33. The method of claim 32, wherein: The top image is a first top image of the pre-aligner; Moving the teaching substrate over the pre-aligner includes moving the teaching substrate over the pre-aligner to a plurality of positions; The sensor data further includes respective top images of the pre-aligner taken by the second camera from respective ones of the plurality of positions, the respective top images including the first top image; and Determining the positions of the plurality of workstations includes identifying positions of the pre-aligners based at least in part on the respective top images.

34. The method of claim 32, wherein: The plurality of sensors further includes a distance measurement sensor; The sensor data further includes a distance from the teaching substrate to the pre-aligner determined by the distance measurement sensor with the teaching substrate positioned over the pre-aligner; and Determining the positions of the plurality of workstations includes identifying a position of the pre-aligner based at least in part on the distance from the teaching substrate to the pre-aligner.

35. The method of claim 22, wherein: The plurality of sensors further includes a third camera to image an area beneath an edge of the teaching substrate; moving the substrate handling robot along the modified route includes inserting the teaching substrate into the chamber through the hatch with the teaching substrate positioned above the chuck; The sensor data further includes an image of the chuck taken by the third camera with the teaching substrate positioned above the chuck; and Determining the positions of the plurality of workstations includes identifying a position of the chuck based at least in part on the image of the chuck captured by the third camera.

36. The method of claim 35, wherein moving the substrate handling robot along the modified route further comprises repositioning the teaching substrate in front of the hatch so that the third camera faces the hatch before inserting the teaching substrate into the chamber.

37. The method of claim 35, further comprising determining an orientation of the chuck based at least in part on the image of the chuck captured by the third camera.

38. The method of claim 22, wherein: The plurality of sensors further includes a distance measurement sensor facing sideways relative to the teaching substrate; Moving the substrate handling robot along the modified route includes: repositioning the teaching substrate in front of the hatch so that the distance measurement sensor faces the hatch, and inserting the repositioned teaching substrate into the chamber through the hatch; The sensor data further includes distance measurements obtained by the distance measurement sensor used to scan the side of the chuck; and Determining the positions of the plurality of workstations includes identifying a position of the chuck based at least in part on the distance measurements.

39. The method of claim 38, wherein: The chuck has a slot for receiving the end effector; and Identifying the position of the chuck includes identifying a position of the slot based at least in part on the distance measurement.

Images