Wireless substrate teaching sensor for semiconductor processing

Abstract

A wireless substrate-based sensor (100) for teaching transfer coordinates to a robotic substrate handling system is provided. The sensor (100) includes a base (104) sized and shaped to be similar to a substrate handled by the robotic substrate handling system. An electronics housing (102) is coupled to the base (104). A power module (200) is disposed within the electronics housing (102) and is configured to supply power to components of the sensor (100). At least one edge camera (108, 110, 112, 114) is disposed near an edge (116) of the base (104). The at least one edge camera (108, 110, 112, 114) has a field of view, and the at least one edge camera images an alignment feature (132) of an object within the field of view of the at least one edge camera (108, 110, 112, 114) of the wireless substrate-based sensor (100). A controller (206) is disposed within the electronics housing (102) and is coupled to at least one edge camera (108, 110, 112, 114). The controller (206) is configured to obtain an image from the at least one edge camera (108, 110, 112, 114) and determine a position of the alignment feature (132), and provide the determined position to the robotic substrate handling system.

Description

Background Art

[0001] Almost all modern electronic products use integrated circuits. These integrated circuits are produced in semiconductor processing facilities using semiconductor materials such as silicon. Semiconductors are typically provided in the form of round, thin wafers that are processed into potentially hundreds or thousands of integrated circuits.

[0002] Semiconductor processing facilities use automated robots to handle materials within the processing chamber. Wafers must be positioned for processing with high accuracy and repeatability. Wafers must be carefully returned to their storage location to avoid collisions that create debris; since debris or dust can have a significant adverse effect on processing yields, the processing environment requires to be very clean.

[0003] Wafer handling systems for semiconductor processing can take a variety of forms. These systems are used to remove wafers from storage containers, move wafers to processing stations, move wafers between processing stations, and / or return processed wafers to containers. Typically, a wafer handling system includes a robotic arm with an end effector that is shaped and sized to be inserted into a container for removal / replacement of a wafer. The end effector may include a vacuum system for clamping or otherwise adhering to the wafer to ensure that it does not slip or shift during transport.

[0004] The end effector must be precisely positionable. Positioning errors in the wafer handling system can lead to unintended contact between the wafer, the end effector, and / or other components of the semiconductor processing system. Even a small impact can dislodge a particle that can contaminate other wafers, resulting in very expensive scrap.

[0005] In some processing steps, the wafer must be very accurately centered on the processing tool to ensure uniform process results across the entire wafer surface. Therefore, handling system positioning errors must be minimized.

[0006] During semiconductor processing, it is often necessary to transfer the wafer to a platform commonly referred to as a "process chuck" and properly position it on the platform. The process chuck is a device used to hold the wafer during one or more process steps. It is usually close to the size and circular shape of the wafer. The chuck may also have vacuum holes so that when the wafer is placed on the process chuck, a vacuum can be used to hold the wafer securely on it. If the wafer is not placed correctly on the process chuck, the edge dies of the wafer will not be processed correctly. These dies will have defects, resulting in yield loss. For some processing steps, such as ion etching and others, the chuck may include special sidewalls that help guide the process. The wafer must be placed very accurately within the sidewalls for the process to be successful.

[0007] In order to reduce positional errors, it is useful to periodically realign the wafer handling system with known marks in the processing tool, wafer storage and transfer container, or both. This is often referred to as "teaching" the wafer transfer coordinates to the wafer handling system to reduce or eliminate any differences between the coordinate system of the wafer handling system and the coordinate system of the semiconductor processing system. CyberOptics of Golden Valley, Minnesota, sells a commercial system under the trade name WaferSense ATS. WaferSense ATS (Automatic Teaching System) uses machine vision to provide calibrated "eyes" that help teach the wafer transfer coordinates to the wafer handling system. The system uses a sensor shaped like a wafer so that it can be processed as accurately as a process wafer. In this way, the sensor can be moved around the semiconductor processing system to measure robot handovers without opening the processing chamber. Opening and closing the processing chamber may consume production interruptions of several hours to several days. Wafer-like sensors can also access difficult-to-reach sites such as pre-aligners and load locks for loading and unloading. The WaferSense ATS sensor is taught to recognize a circular target feature (e.g., the center hole on a chuck) and uses machine vision and its onboard signal processing to measure the XYZ offset from the sensor’s calibrated geometric center to the center of the target feature. The ATS sensor allows equipment users to save time by not opening the process chamber during equipment maintenance, and accurate robotic teaching ensures proper transfer of the wafer to the center of the process chuck.

[0008] Current ATS sensors require a circular shaped target in the center of the wafer chuck so that the ATS can use it to calculate the deviation between the wafer and the chuck. Additionally, the robot blade or end effector needs to have an unobstructed opening or port so that the ATS sensor's camera can look through it to find the circular shape of the process chuck. However, a large percentage of semiconductor processing equipment (~>70%) does not have a circular target on the process chuck, or the end effector does not have the required center opening. In these cases, current ATS sensors are limited and may not be suitable for teaching wafer transfer coordinates to a wafer handling system. Therefore, it would be beneficial to provide an automatic teaching sensor for a wafer handling system that can perform the teaching function without the need for a center hole in the process chuck or a center opening in the end effector. Such a sensor would allow the benefits of automatic wafer transfer coordinate teaching to reach more applications. Summary of the invention

[0009] A wireless substrate-based sensor for teaching transfer coordinates to a robotic substrate processing system is provided. The sensor includes a base that is sized and shaped to be similar to a substrate processed by the robotic substrate processing system. An electronic housing is coupled to the base. A power module is disposed within the electronic housing and is configured to supply power to components of the sensor. At least one edge camera is disposed near an edge of the base of the wireless substrate-based sensor. The at least one edge camera has a field of view, and the at least one edge camera images alignment features of an object within the field of view of the at least one edge camera of the wireless substrate-based sensor. A controller is disposed within the electronic housing and coupled to the at least one edge camera. The controller is configured to obtain an image from the at least one edge camera, determine a position of the alignment feature, and provide the determined position to the robotic substrate processing system. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figures 1A to 1C is a schematic diagram of a substrate sensor with process chuck edge detection according to an embodiment of the present invention.

[0011] Figure 2 is a schematic diagram of an edge camera of the improved sensor that images a portion of the edge of a chuck in the field of view (FOV) of the edge camera, and the FOV is illuminated by a point light source.

[0012] Figure 3 is a schematic diagram showing an example of structured light that can be imaged by a camera, with subsequent images processed by the sensor for accurate determination of pitch.

[0013] Figure 4A and Figure 4B is a schematic diagram of a wireless wafer shape teaching sensor according to an embodiment of the present invention.

[0014] Figure 5 is a flow chart of a method for training a wafer processing robot according to an embodiment of the present invention. DETAILED DESCRIPTION

[0015] Known automated teach systems for semiconductor processing tools typically employ a single centered camera that looks for a single centered circular object on the process chuck (wafer platform). The camera looks almost perfectly straight down, perpendicular to the sensor body. Relatively simple processing is used to locate the circular object in the camera image and compare its center to the calibrated sensor center. A ring light surrounding the camera's FOV provides illumination.

[0016] According to embodiments described herein, an automatic teaching wireless substrate-like sensor for semiconductor processing tools is provided with multiple cameras located near the outer edge of the sensor. The new system and method use one or more cameras located near the edge of the sensor to observe the physical edge of the process chuck and measure its positioning and / or curvature relative to the sensor. Alignment marks visible to one or more edge cameras can be used instead of or in addition to the chuck edge. These cameras can be used without a center camera, or they can be used to supplement the center camera. The line of sight of these edge observation cameras must adapt to a relatively large viewing angle to view the edge of a process chuck with a nominal diameter that is the same as the diameter of the sensor. Because this viewing angle tightly couples the lateral positioning (XY) with the distance (Z or range) from the camera to the process chuck, it is important to accurately know the Z (range) in order to report accurate XY. In one embodiment, the measurement of the Z range is performed using structured lighting, so it is important to pair each edge camera with an illuminator that uses some structured light and calibrate it using it. This structured light and calibration of the camera and illuminator allows accurate determination of the spacing to the edge of the chuck and compensation for lateral offsets caused by small changes in spacing. This also provides a method for calculating and reporting the accurate Z (spacing) between the wireless substrate-based sensor and the process chuck surface at the edge camera position. Other embodiments of the present invention may use other methods to determine the spacing from the camera to the chuck. An example of another method of obtaining Z is by ultrasonic ranging or time of flight.

[0017] Additionally, the camera views should be calibrated to accurately relate the positioning of each field of view to all other fields of view and to a single global coordinate system of the sensor. One camera field of view (e.g., the field of view of the center camera) can be used to define a single global coordinate system. Alternatively, a single global coordinate system can be defined based on physical features of the sensor (e.g., the outer edge of the sensor, an alignment notch, or an alignment hole).

[0018] The embodiments described herein typically utilize multiple cameras disposed on a substrate-based sensor in order to image geometric features (e.g., edges) of a process chuck. Thus, instead of using only a centered circular mark, detection of other alignment marks at or near the edge of the process chuck can now be used to align the end effector and process chuck. The wireless substrate-based sensor is shaped and sized to be similar to the wafer to be processed. In addition, other alignment features within the views of the multiple cameras can be used as a reference for the system to automatically calculate X&Y distances and (optionally) Z distances and angular directions to realign and realign the end effector.

[0019] Figures 1A to 1Cis a schematic diagram of a wireless substrate-based sensor with improved chuck edge detection according to one embodiment. Figure 1A shows a top view, while Figure 1B shows a side view, and Figure 1C A bottom view is shown.

[0020] Figure 1A and Figure 1C A wireless substrate-type sensor 100 having a circular shape is shown, which has a circular raised portion 102, and the circular raised portion 102 accommodates an electronic device therein (refer to Figure 4A and Figure 4B 100 is a wafer-like sensor having a circular shape (similar to a circular wafer), it is clearly contemplated that other shapes may be used. An important aspect of the substrate-like feature is that it allows the sensor 100 to move in the processing environment in the same manner as the substrate as it is processed. Thus, in a reticle processing facility, the substrate-like sensor may be shaped as a rectangle. Figure 1A and Figure 1C In the illustrated embodiment, the sensor 100 includes a base that preferably has the same diameter as the diameter of the processed wafer. In one example, for a processing system processing a 300 mm diameter wafer, the outer diameter is 300 mm. In another embodiment, for a system processing a 200 mm wafer, the diameter of the base 104 is 200 mm. The base 104 is preferably formed of a relatively rigid material such as carbon fiber or chemically hardened glass (e.g., Gorilla Glass available from Dow Corning of Midland, Michigan).

[0021] Figure 1C A central camera 106 is shown arranged along with four additional cameras 108, 110, 112, and 114 arranged near an outer edge 116 of the sensor 100. The sensor 100 also includes one or more structured illumination sources ( Figure 2 Preferably, a structured illuminator or structured illumination source is provided for each of the cameras 108, 110, 112 and 114. Figure 1C In the illustrated embodiment, four cameras 108, 110, 112, and 114 are arranged at approximately 90 degree intervals near the edge 116 of the sensor 100. However, those skilled in the art will recognize that more or fewer cameras away from the center may be used in accordance with embodiments of the present invention. In addition, although the outer edge cameras 108, 110, 112, and 114 are evenly spaced from each other, it is also contemplated that embodiments of the present invention may be practiced with unequal spacing between the cameras.

[0022] Figure 2 1 is a schematic diagram of an edge camera (e.g., camera 108) of a wireless substrate-based sensor that images a portion 130 of a process chuck edge 132 in the FOV 134 of the edge camera 108 when a structured illuminator 136 (schematically shown as a point light source) illuminates the field of view (FOV) 134. The illustration is intended to show a paired camera and illuminator. As described above, the pairing of the camera and illuminator facilitates calibration of the camera, which allows accurate determination of the spacing to the edge 132 of the process chuck 138. The camera 108 can be any suitable device capable of obtaining a useful image of the field of view. The camera 108 can be a monochrome camera or a color camera. Typically, the camera 108, as well as the cameras 110, 112, and 114, are area array devices, such as charge coupled devices (CCDs) or complementary metal oxide semiconductor (CMOS) image devices. These cameras can include or be coupled to a suitable optical system (not separately shown) to focus the image on the array within the camera.

[0023] Figure 3 is a schematic diagram showing a very simple example of structured illumination that can be calibrated and used for accurate determination of pitch. Figure 3 In FIG. 1 , the structured illumination is in the form of a single point. Through calibration, the size and nominal positioning of point 140 are known to the sensor controller (e.g., Figure 4A and Figure 4B 108). When an image of point 140 is acquired by a camera (e.g., camera 108), comparing the apparent size and position of point 140 in the image with known calibration information facilitates the camera / illuminator pair to provide an accurate standoff (i.e., distance to an object) determination. The positioning of the structured illumination in the camera image is calibrated with respect to height so that the observed positioning in the image can be processed to provide an accurate Z measurement. Figure 3 A simple example is shown, but those skilled in the art will recognize that the structured lighting pattern can take many forms, such as but not limited to: a dot, more than one dot, a cross, a circle, multiple lines, a sinusoidally varying pattern, a diamond, and a checkerboard.

[0024] Figure 4A is a schematic diagram of a wireless wafer shape teaching sensor according to an embodiment of the present invention. Figure 4Ais a schematic diagram of the circuitry within the circular raised portion 102 according to an embodiment of the present invention. As shown, the power module 200 preferably includes a battery 202 to power the sensor 100 when it is moved within a semiconductor processing facility. Preferably, the battery 202 is a rechargeable battery. The power module 200 is configured to provide necessary power to various other components of the sensor 100, as shown by the arrow 204 labeled "To All". In one example, the power module 200 can include a power management integrated circuit available from Texas Instruments under the trade name TPS5602.

[0025] The controller 206 is coupled to the power module 200 and receives power from the power module 200. The controller 206 is configured to programmatically execute instructions through hardware, software, or a combination thereof to obtain image data from a camera coupled thereto. The controller 206 may be configured to use a communication circuit 207 to send an image to a receiving hardware external to the sensor wafer, where the image may be stored or processed. In a preferred embodiment, the sensor controller will perform processing to identify features in the image indicating a reference position (e.g., an edge portion of a process chuck), and calculate a reference position (i.e., the center of the process chuck) based on the reference position and the stored calibration information. In addition, the controller 206 is configured to use the communication circuit 207 to send information indicating the reference position to a robot handling system or other suitable device to teach the reference position to the robot handling system. In one example, the controller is a microprocessor, such as a microprocessor sold under the trade name TMS320C6211 obtained from Texas Instruments. The controller 206 is also coupled to or includes a memory 208, which may take the form of any type of memory. Preferably, however, the memory 208 comprises a module of synchronous dynamic random access memory (SDRAM), preferably having a size of at least 16M×16. The memory 208 also preferably comprises a flash memory having a size of 256K×8. The flash memory is used to store non-volatile data such as programs, calibration data, and / or additional other non-changing data that may be required. The random access memory is used to store volatile data, such as acquired images or data related to program operation. The memory 208 contains instructions that, when executed by the controller 206, perform the functions described herein.

[0026] The lighting module 210 is coupled to the controller 206 and structured illuminators 212, 214, 216, and 218. Each structured illuminator 212, 214, 216, 218 is preferably located on the underside of the base 104, near the corresponding camera 108, 110, 112, and 114. The structured illuminator generates lighting with a specific structure, such as Figure 3As shown, this particular structure allows the spacing to be calibrated for each camera / illuminator pair. The structured light illuminator can apply sufficient monochromatic or polychromatic light to the camera FOV to allow a suitable image to be recorded. The structured illuminator can include an LED, a laser diode, or any other suitable device.

[0027] like Figure 4A As shown, the controller 206 is coupled to all of the cameras 220, 222, and 224. The camera 220 may be a center camera similar to cameras used in the prior art. In addition, in an environment where the camera 220 has an unobstructed view of the center hole on the process chuck, the controller 200 may perform coordinate teaching using prior art techniques. The controller 200 is also coupled to various edge cameras 222, 224 to provide coordinate teaching according to embodiments of the present invention. The camera 224 may be a center camera similar to cameras used in the prior art. In addition, in an environment where the camera 220 has an unobstructed view of the center hole on the process chuck, the controller 200 may perform coordinate teaching using prior art techniques. Figure 4A and Figure 4B 224. The edge cameras 222, 224 may be used in any suitable number of embodiments. In addition, the controller 200 may be adjusted by hardware, software, or a combination thereof to determine if the camera 220 has an obstructed view, or if a center hole or feature is not provided on the process chuck and automatically employ an edge camera to calculate the center of the process chuck.

[0028] The communication circuit 207 is coupled to the controller 206 to allow the controller 206 to communicate, preferably bidirectionally, during operation within the semiconductor processing environment. The communication circuit 207 may employ any suitable wireless communication protocol and / or frequency. In one example, the communication circuit operates at approximately 2.4 GHz in accordance with the well-known Bluetooth standard (Bluetooth Core Specification Version 1.1 (February 22, 2001)) available from the Bluetooth SIG (www.bluetooth.com). An example of the circuit 207 is available from Mitsumi under the trade name WML-C11.

[0029] In order to provide higher accuracy and precision, the embodiments described herein generally facilitate calibrating each edge camera / illuminator pair so that the spacing to the edge of the process chuck can be accurately determined and used to compensate for lateral offsets caused by spacing variations. According to one embodiment, the sensor is placed in a precision fixture or calibration device with a known spacing. At least one edge camera is caused to record one or more images at one or more known spacings. Then, the controller 206 processes the one or more images obtained to associate the appearance of the structured lighting in the one or more images with the known spacing. The calibration method establishes calibration information, which is used to measure the spacing according to the appearance of the structured light in the image during teaching. The calibration information can be in the form of a lookup table or coefficients of a functional representation of the calibration information. The controller's use of the calibration information may involve interpolation between stored calibration points or extrapolation beyond the stored calibration range. In addition, since the sensor may be sensitive to environmental changes, the calibration information may include reliance on auxiliary measurements of temperature, humidity, pressure and other environmental variables.

[0030] Figure 4B FIG. 4 is a schematic diagram of a wireless wafer shape teaching sensor according to another embodiment of the present invention. Figure 4B The embodiment shown is Figure 4A The embodiments shown have many similarities, and similar components are numbered similarly. The main differences between the embodiments are that Figure 4B It is shown that the distance measuring devices 412, 414, 416 and 418 can be used instead of the structured illuminator. These distance measuring devices can use any suitable technology to determine the spacing or distance from the wireless substrate type sensor to the object or process chuck. In a preferred embodiment, the distance measuring devices 412, 414, 416 and 418 are driven or otherwise controlled by the distance measuring device circuit 410 coupled to the controller 206. Although Figure 4B Multiple ranging devices are shown being used, but it is clearly contemplated that embodiments of the present invention may be practiced using a single ranging device in conjunction with a tilt / tip sensor 420 mounted to a wireless substrate-type sensor and coupled to a controller to provide an indication of sensor tilt / tilt. Such a tilt / tilt sensor may also be used in conjunction with a single structured illuminator such as those described above.

[0031] Figure 5300 is a flow chart of a method for teaching a wafer processing robot according to an embodiment of the present invention. Method 300 begins at box 302, where a sensor is loaded or otherwise disposed on an end effector of a semiconductor processing robot. This can be accomplished 304 by a technician manually placing the sensor on the end effector, or automatically accomplished 306 by causing the semiconductor processing robot to withdraw the sensor from a known sensor location (e.g., a base station, or a location in a wafer processing box or container). Next, at box 308, the sensor is brought to the vicinity of a transfer position by the semiconductor processing robot. As defined herein, a transfer position is any position in a semiconductor processing facility where a semiconductor substrate (e.g., a wafer or mask) leaves the end effector of a semiconductor processing robot, or is picked up or otherwise engaged by the end effector of a semiconductor processing robot. Thus, a process chuck is one such transfer position.

[0032] At box 310, the sensor acquires at least one edge image of the transfer location. In one example, the transfer location is a circular process chuck. As shown in box 312, it is believed that embodiments of the present invention can be practiced using a single camera with a FOV covering the edge of the process chuck. For example, in the acquired image, the curved outer edge can be identified by the image processor (e.g., controller 206). The curved edge can be fit to a circle and the center can be found from the fitted circle. Therefore, even if the sensor cannot see the center of the process chuck, or if the center does not have a reference feature (such as a hole), the embodiments described herein can still provide automatic teaching of wafer transfer coordinates to the semiconductor processing system. Although it is believed that embodiments of the present invention can be practiced using a single edge camera, it is believed that multiple cameras (as shown in Figure numerals 314 and Figure 1C Higher accuracy can be achieved.

[0033] Next, at box 316, a controller (e.g., controller 206) uses one or more images of the curved edge of the process chuck to calculate the center positioning of the process chuck. The center calculation can be completed in any suitable manner. The edge arcs of the circles identified in each camera image can be combined and then mathematically fitted into a single circle using a method stored in the controller 206. Alternatively, the edge arcs of each camera can be fitted into its own circle, and the centers of the resulting circles of each camera can be appropriately combined to obtain a single center result. Adding additional edge cameras will further improve the accuracy of the sensor. Finally, at box 320, the sensor provides the calculated center coordinates to the processing system to teach the processing system the transfer position. Preferably, this is done using wireless communication, such as using wireless communication circuit 207.

[0034] Those skilled in the art will readily appreciate that, without departing from the spirit and scope of the present invention, a variety of modifications may be made. Examples of modifications include providing various forms of structured illumination, such as sinusoidal curves or repeated rhombuses. The Z spacing may be determined optically using the structured illumination described in detail above, but may also be determined by other means, such as ultrasonic or capacitive ranging, or by a combination of ranging in various ways in conjunction with accurate determination of the relative inclination of the chuck and the sensor at a single point. In addition, more than one camera may be associated with a single illumination source, and / or more than one illumination source may be associated or paired with a single camera. The illumination of one or two illuminators may be a single wavelength or multiple wavelengths. Similarly, cameras may be used to detect and possibly record color or monochrome images. Single or multiple images may be used to achieve desired XY positioning results. Finally, the height (Z) value may be used for purposes of determining accurate X and Y separation.

[0035] Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.

Claims

1. A wireless substrate sensor for teaching transfer coordinates to a robotic substrate handling system, the sensor comprising: a base sized and shaped to be similar to a substrate handled by the robotic substrate handling system; an electronics housing coupled to the base; a power module disposed within the electronics housing and configured to supply power to components of the sensor; at least one edge camera disposed near an edge of the base, the at least one edge camera having a field of view, the at least one edge camera imaging an edge of a process chuck within the field of view of the at least one edge camera of the wireless substrate-based sensor, the process chuck being configured to receive a semiconductor wafer; a distance measuring device mounted relative to the base and operably coupled to the controller to provide an indication of the spacing between the wireless substrate-based sensor and the process chuck; A controller is disposed in the electronic housing, the controller is coupled to the at least one edge camera and the ranging device, the controller is configured to obtain an image from the at least one edge camera, and determine the position of the process chuck based on at least one image of the edge of the process chuck and the indication of the spacing, wherein the controller is configured to: determine the spacing correction (X, Y) position of the process chuck based on the at least one image and the indication of the spacing, and send the spacing correction position of the process chuck to the robotic substrate processing system to teach the determined positioning to the robotic substrate processing system. 2 . The wireless substrate type sensor according to claim 1 , further comprising an additional camera disposed in a central area of ​​the base and configured to image a central portion of an object located below the wireless substrate type sensor.

3. The wireless substrate type sensor according to claim 1, wherein: The edge is a rounded edge.

4. The wireless substrate-based sensor of claim 1, further comprising a tilt / slope sensor operably coupled to the controller to measure tilt and slope of the wireless substrate-based sensor.

5. The wireless substrate sensor according to claim 4, wherein: The controller is configured to utilize the indication of the standoff and the measurement of tilt and skew to correctly report XY coordinates from the camera image.

6. The wireless substrate sensor according to claim 1, wherein: The at least one edge camera includes four edge cameras, each of the edge cameras being disposed near an edge of the base.

7. The wireless substrate-type sensor according to claim 1 further comprises a structured illuminator, which is mounted near at least one edge camera relative to the base, and the structured illuminator is configured to generate structured illumination in the field of view of the at least one edge camera.

8. The wireless substrate sensor according to claim 7, wherein: The wireless substrate-based sensor includes at least four edge cameras and a structured illuminator disposed near each corresponding edge camera.

9. The wireless substrate type sensor according to claim 7, wherein: The structured illumination has a form selected from the group consisting of: a dot, a circle, a plus sign, a plurality of parallel lines, a sinusoidally varying intensity pattern in at least one of the X-direction and the Y-direction, a diamond shape, and a checkerboard.

10. The wireless substrate type sensor according to claim 7, wherein: The structured illumination is configured to allow a calibration operation to calibrate an apparent distance based on the structured illumination.

11. The wireless substrate type sensor according to claim 10, wherein: The controller is configured to perform the calibration operation for each pair of edge camera and structured illuminator.

12. The wireless substrate type sensor according to claim 10, wherein: The controller is configured to utilize the stored calibration information to accurately calculate the standoff based on the appearance of the structured lighting in the camera image.

13. The wireless substrate type sensor according to claim 1, wherein: The controller is configured to utilize the measured separation to correctly report XY coordinates from the camera image.

14. The wireless substrate type sensor according to claim 1, wherein: The controller is configured to employ a camera near the center of the sensor base to attempt to image the center hole of the process chuck and selectively engage the at least one edge camera if the attempt to image the center hole of the process chuck fails.

15. The wireless substrate type sensor according to claim 1, wherein: The at least one edge camera is a monochrome camera.

16. The wireless substrate type sensor according to claim 1, wherein: At least one edge camera is a color camera.

17. The wireless substrate type sensor according to claim 1, wherein: The sensor has a substantially similar form to a semiconductor wafer.

18. The wireless substrate type sensor according to claim 1, wherein: The sensor has a form substantially similar to a semiconductor process mask.

19. The wireless substrate type sensor according to claim 1, wherein: The at least one edge camera is disposed on a bottom side of the base.

20. The wireless substrate type sensor according to claim 1, wherein: The distance measuring device is disposed on the bottom side of the base.

21. The wireless substrate type sensor according to claim 7, wherein: The structured illuminator is disposed on the bottom side of the base.

22. A method of measuring a position of a process chuck of a semiconductor processing tool relative to a sensor held by a robotic manipulator of the semiconductor processing tool, the method comprising: providing a sensor having at least one edge detection camera and a range finding sensor; causing the at least one edge detection camera to obtain at least one image of a circular outer surface of the process chuck; enabling the distance measuring sensor to detect the distance from the process chuck; calculating a position of a center of the process chuck based on analyzing the at least one image of the circular outer surface of the process chuck and the detected spacing; as well as The calculated position of the center of the process chuck is communicated to a controller of the robotic manipulator.

23. The method of claim 22, further comprising providing a structured illuminator for each of the at least one edge camera and calibrating each camera / illuminator pair for range finding using structured illumination.

24. The method of claim 23, further comprising obtaining at least one subsequent image of the circular outer surface of the process chuck using the calibrated sensor.

25. The method of claim 22, further comprising calculating lateral (XY) distances and pitch (Z) distances using the stored calibration information.

26. The method of claim 22, wherein: Transmitting the calculated position includes sending wireless data indicative of the calculated position to the controller of the robotic manipulator.

27. The method of claim 22, wherein: The at least one edge detection camera includes four edge detection cameras, and wherein calculating the location of the center of the process chuck includes analyzing at least one image from each edge detection camera.

28. The method of claim 22, wherein: Providing the sensor includes positioning the sensor with the robotic manipulator at a height above the process chuck to obtain the at least one image of the circular outer surface of the process chuck.

29. The method of claim 22, wherein: The sensor held by the robotic manipulator further comprises a tilt sensor, and wherein a signal of the tilt sensor is at least partially used to calculate the position of the center of the process chuck.

30. A method of measuring a position of a process chuck within a semiconductor processing tool relative to a sensor held by a robotic manipulator of the semiconductor processing tool, the method comprising: providing a sensor having at least one edge detection camera and a range finding sensor; causing the at least one edge detection camera to obtain at least one image of an alignment mark of the process chuck that is within a field of view of the at least one edge camera; enabling the distance measuring sensor to detect the distance from the process chuck; calculating a position of an alignment mark of the process chuck based on the at least one image of the alignment mark and the detected spacing; as well as The calculated position is communicated to a controller of the robotic manipulator.

31. The method of claim 30, further comprising providing a structured illuminator for each of the at least one edge camera and calibrating each camera / illuminator pair for range finding using structured illumination.

32. The method of claim 31 further comprising obtaining at least one subsequent image of an edge of the process chuck using the calibrated sensor.

33. The method of claim 30, further comprising using the stored calibration information to calculate lateral (XY) distances and pitch (Z) distances.

34. The method of claim 30, wherein: Transmitting the calculated position includes sending wireless data indicative of the calculated position to a controller of the robotic manipulator.

35. The method of claim 30, wherein: The at least one edge detection camera includes four edge detection cameras, and wherein calculating the position of the alignment mark includes analyzing at least one image from each edge detection camera.

36. The method of claim 30, wherein: The sensor held by the robotic manipulator further comprises a tilt sensor, and wherein a signal of the tilt sensor is at least partially used to calculate a position of an alignment mark of the process chuck.

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