Substrate transfer apparatus and substrate position deviation measurement program

Abstract

To provide a compact substrate transfer apparatus.SOLUTION: A substrate transfer apparatus (1) includes: a robot (10) having a hand (12) that holds a substrate (W) and an arm (11) that moves the hand (12); a robot control device (15) that sets a movement path (T) for the hand (12) and controls the arm (11) such that the hand (12) moves on the movement path (T) toward a target position (Py); and a camera (6) that is positioned so as to be able to photograph the substrate (W) held by the hand (12) that is positioned at a predetermined confirmation position (Px). The robot control device (15) sets the movement path (T) to pass through the confirmation position (Px), acquires an image (G) taken by the camera (6) when the hand (12) is positioned at the confirmation position (Px), calculates a distance between the substrate (W) shown in the image (G) and a predetermined environment, and calculates a positional deviation amount (L) of the substrate (W) from a reference position (S) on the basis of the distance.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a substrate transport device and a substrate positional deviation measuring method. [Background technology]

[0002] Conventionally, automatic substrate alignment devices have been known. For example, the automatic substrate alignment device disclosed in Patent Document 1 includes two sensors, two light sources, and a transport chuck for transporting the substrate. The sensors and light sources are installed above and below the substrate, symmetrically positioned with respect to the substrate transport direction, with the peripheral edge of the substrate intersecting between the two sensors and the light sources. The transport chuck then suction-holds and moves the substrate, and calculates the center position of the substrate based on the sensor outputs when the two sensors are shielded from light. The device then calculates the amount of deviation of the substrate from the reference point coordinates. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 63-94653 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the automatic alignment device described in Japanese Patent Laid-Open No. 63-94653 requires the substrate to be moved significantly in a straight line in the conveying direction in order to calculate the amount of misalignment, which poses a problem of making the device large in size. [Means for solving the problem]

[0005] In order to solve the above problem, a substrate transport device according to one aspect of the present invention comprises a robot having a hand that holds a substrate and an arm that moves the hand, a robot control device that sets a movement path for the hand and controls the arm so that the hand moves along the movement path toward a target position, and a camera that is positioned so as to be able to photograph the substrate held by the hand that is positioned at a predetermined confirmation position, wherein the robot control device sets the movement path to pass through the confirmation position, acquires an image taken by the camera when the hand is positioned at the confirmation position, calculates the distance between the substrate shown in the image and a predetermined environment, and calculates the amount of positional deviation of the substrate from a reference position based on the distance.

[0006] According to this configuration, it is possible to measure the positional deviation of the substrate at the check position, and it is possible to make the substrate transport device compact so as to compensate for the positional deviation of the substrate. [Effects of the Invention]

[0007] The present invention has the effect of making the substrate transport device compact. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view showing an example of the configuration of substrate processing equipment including a substrate transfer device according to an embodiment; [Figure 2] 2 is a plan view showing an example of the configuration of the substrate processing equipment of FIG. 1. [Figure 3] 1. FIG. 4 is a plan view showing an example of operation of the substrate processing equipment of FIG. 1, showing a state in which a hand is located at a check position. [Figure 4] 1. FIG. 4 is a diagram showing an example of operation of the substrate processing equipment of FIG. 1, showing an image captured by a camera of a hand positioned at a check position. [Figure 5] 1. FIG. 4 is a plan view showing an example of operation of the substrate processing equipment of FIG. 1, showing a state in which the movement path of a hand is corrected. [Figure 6] FIG. 2 is a diagram showing a modification of the substrate transport device of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described with reference to the drawings. Note that the present invention is not limited to the following embodiments. In addition, the same or corresponding elements will be denoted by the same reference numerals throughout the drawings, and redundant description will be omitted.

[0010] Fig. 1 is a perspective view showing an example of the configuration of a substrate processing facility 100 including a substrate transfer device 1 according to an embodiment. Fig. 2 is a plan view showing the example of the configuration of the substrate processing facility 100.

[0011] 1 and 2, the substrate processing equipment 100 is equipment for performing various processes on a substrate W, such as heat treatment, impurity introduction treatment, thin film formation treatment, lithography treatment, cleaning treatment, and planarization treatment. In this embodiment, the substrate W is a semiconductor wafer, and examples thereof include a silicon wafer, a sapphire (single crystal alumina) wafer, and various other wafers. The substrate W may also be a glass substrate, and examples of the glass wafer include a glass substrate for an FPD (Flat Panel Display) and a glass substrate for an MEMS (Micro Electro Mechanical Systems).

[0012] The substrate processing equipment 100 includes a chamber 3 and a transfer chamber 4, and the chamber 3 is connected to the transfer chamber 4 via a gate 5. A substrate transfer device 1 is installed in a transfer chamber 41 of the transfer chamber 4. Substrates W are transported to the substrate processing equipment 100 in a state where multiple substrates W are accommodated in a carrier 110 called a FOUP (Front Opening Unified Pod), which is connected to the transfer chamber 4. The substrate transfer device 1 then removes the substrate W from the carrier 110 and transfers it to a substrate placement position Pp in a room 31 of the chamber 3 via the transfer chamber 41 of the transfer chamber 4. A stage 32 for placing the substrate W is provided at the substrate placement position Pp. The room 31 is, for example, a processing chamber for performing various processes on the substrate W, or a transfer chamber for transporting the substrate W to another chamber 3. The substrate W being transported from the transfer chamber 4 to the chamber 3 passes through an opening 51 of the gate 5 provided between the room 31 of the chamber 3 and the transfer chamber 41 of the transfer chamber 4. The gate 5 separates the room 31 from the transfer chamber 41. The opening 51 is a passageway that opens toward the room 31 and the transfer chamber 41 and connects the room 31 to the transfer chamber 41. An opening periphery 52 of the opening 51 is formed, for example, in a substantially horizontally elongated rectangle, and the opening 51 has a width dimension that is larger than the diameter of the substrate W. Furthermore, the substrate placement position Pp is positioned on a straight line that extends from the gate 5 in the depth direction of the room 31 in a plan view. This allows the substrate W to be positioned at the substrate placement position Pp by inserting it straight through the gate 5 (specifically, from a confirmation position Px, which will be described later).

[0013] The substrate W transferred to the substrate placement position Pp is then subjected to a predetermined process in the chamber 3 or the like. The substrate W is then transferred from the substrate placement position Pp to the carrier 110 by the substrate transfer device 1, and is then accommodated in the carrier 110 again. To prevent particles from adhering to the substrate W during these processes, the substrate processing equipment 100 includes a device (not shown) for maintaining a high level of cleanliness in the room 31 and the transfer chamber 41. The gate 5 also functions as a partition for maintaining a high level of cleanliness on the chamber 3 side.

[0014] The substrate transfer device 1 is a device for transferring a substrate W, and includes a robot 10, a robot control device 15, and a camera 6.

[0015] The robot 10 is, for example, a horizontally articulated SCARA robot. The robot 10 is moved three-dimensionally, i.e., in three mutually perpendicular axis directions, by an arm 11. The robot 10 includes a base 14 installed in a transfer chamber 41, the arm 11, a hand 12, and an arm driver 13.

[0016] The hand 12 is a passive hand and includes a blade 23 and a wrist 24 connected to the base end of the blade 23. The blade 23 is generally flat and is held by the arm 11 so that its upper surface remains horizontal. The blade 23 holds the substrate W placed thereon by friction via three pads 23a provided on its upper surface. Note that the hand 12 is not limited to a passive hand, and may be a suction hand that suction-holds a workpiece such as a Bernoulli hand, or an edge grip hand that grips the edge of the substrate W.

[0017] The arm 11 has a multi-joint structure including multiple joints, with its base end connected to a base 14 and its tip end connected to a wrist 24. The arm 11 includes multiple links (an elevator shaft 20, a lower arm 21, an upper arm 22) that are sequentially connected via joints in the direction from the base end to the tip end.

[0018] The lifting shaft 20 is connected to the base 14 so as to be movable in the vertical direction. The lower arm 21 has a base end connected to the upper end of the lifting shaft 20 via a joint so as to be rotatable about a rotation axis extending in the vertical direction. The upper arm 22 has a base end connected to the tip of the lower arm 21 via a joint so as to be rotatable about a rotation axis extending in the vertical direction. The wrist 24 has a base end connected to the tip of the upper arm 22 via a joint so as to be rotatable about a rotation axis extending in the vertical direction.

[0019] The arm driver 13 is a mechanism that rotates the lower arm 21, the upper arm 22, and the blade 23 at their joints to move the hand 12 in the horizontal direction. The arm driver 13 also moves the entire arm 11 up and down by raising and lowering the lifting shaft 20, thereby moving the hand 12 up and down.

[0020] The robot control device 15 sets a movement path T of the indication point P according to a predetermined operation program. In this embodiment, the movement path T includes a path along which the hand 12 picks up the substrate W to be transported from the carrier 110, and thereafter, the indication point P passes through the confirmation position Px and reaches the target position Py. The indication point P is set, for example, on the central axis of a circle defined by the points where the three pads 23a of the blade 23 are located. The confirmation position Px is set, for example, at the center of the opening 51. Note that, at this confirmation position Px, the hand 12 may take a posture extending toward the target position Py. The target position Py is set at the center of the substrate placement position Pp, and at this position, the hand 12 maintains the posture at the confirmation position Px. Then, the robot control device 15 controls the arm 11 so that the indication point P of the hand 12 moves along the movement path T toward the target position Py. The information related to the movement path T includes not only information that defines the displacement of the position of the hand 12, but also information that defines the displacement of the posture of the hand 12. Similarly, the confirmation position Px and the target position Py also include information that defines the posture of the hand 12. The robot control device 15 is configured to be able to correct the movement path T.

[0021] The robot control device 15 includes, for example, a control unit having a computing unit such as a CPU, and a storage unit having memory such as ROM and RAM. The control unit may be configured as a single controller for centralized control, or may be configured as multiple controllers for distributed control in cooperation with each other. The storage unit stores a program for generating a movement path T, and the computing unit executes the program to control the position and posture of the hand 12.

[0022] The camera 6 is, for example, a stereo video camera capable of capturing a stereoscopic image of an object. The camera 6 is used to detect misalignment of the substrate W. The camera 6 is positioned so as to capture an image of the substrate W held by the hand 12 located at the confirmation position Px. In this embodiment, the camera 6 is attached to a position below the opening 51 on the side of the gate 5 facing the transfer chamber 41, so as to simultaneously capture an image of the substrate W held by the hand 12 located at the confirmation position Px and the opening 51. The camera 6 is directed obliquely upward so as to include the periphery 52 of the opening 51 in its field of view. This reduces reflected light from the surface of the substrate W that appears in the captured image G, enabling accurate image processing. Furthermore, positioning the camera 6 on the underside of the substrate W prevents particles from adhering to the upper surface of the substrate W. The image G captured by the camera 6 is input to the robot control device 15. The camera 6 may be a general-purpose camera that can be used for purposes other than detecting misalignment of the substrate W. Furthermore, since the camera 6 is a stereo video camera that can capture an object in three dimensions, the distance between the camera 6 and the substrate W can be obtained.

[0023] [Example of operation] Next, an example of the operation of the substrate transfer device 1 will be described.

[0024] 2, first, the robot control device 15 sets a movement path T. Then, the robot control device 15 controls the arm 11 so that the hand 12 picks up the substrate W to be transported from the carrier 110.

[0025] 3 is a diagram showing a state in which the indication point P of the hand 12 is located at the check position Px. In FIG. 3, an example is shown in which the center C of the substrate W is shifted from the indication point P of the blade 23 and the substrate W is placed on the blade 23.

[0026] Next, the robot control device 15 controls the arm 11 so that the indication point P of the hand 12 holding the substrate W moves on the movement path T toward the confirmation position Px, which is a via point. Then, as shown in Fig. 3, the robot control device 15 temporarily stops the hand 12 when the indication point P of the hand 12 is located at the confirmation position Px.

[0027] FIG. 4 is a diagram showing an image G captured by the camera 6 of the hand 12 positioned at the check position Px.

[0028] Next, the robot control device 15 acquires an image G captured by the camera 6 when the indication point P of the hand 12 is located at the confirmation position Px. Then, as shown in FIG. 4 , the robot control device 15 calculates the distance between the substrate W captured in the image G and a predetermined environment surrounding the substrate transport device 1 and the substrate W, and calculates the amount of positional deviation L of the substrate W from the reference position S based on this distance. In this embodiment, the predetermined environment is the opening periphery 52, and more specifically, the left and right side edges extending in the vertical direction of the opening periphery 52. ​​The robot control device 15 calculates the dimension of a gap 53 between the substrate W and the adjacent opening periphery 52, and calculates the amount of positional deviation L of the substrate W from the reference position S based on the dimension of the gap 53. Note that the positional deviation of the substrate W may be caused by a positional deviation of the hand 12. The positional deviation of the hand 12 occurs, for example, due to low repeatability of the robot 10.

[0029] Specifically, the robot control device 15 calculates a dimension La of a first gap 53a, which is a gap between a first end We1 of the substrate W and the opening periphery 52 in the misalignment direction D shown in the image G, and a dimension Lb of a second gap 53b, which is a gap between a second end We2 and the opening periphery 52. ​​The misalignment direction D is a direction in which the amount of misalignment is measured, for example, the width direction of the opening 51. The first end We1 and the second end We2 may be portions on a straight line Ls that extends in the misalignment direction D and passes through the center C of the substrate W. The first gap 53a may be a gap between the first end We1 and a portion where the straight line Ls passes through the opening periphery 52. ​​Similarly, the second gap 53b may be a gap between the second end We2 and a portion where the straight line Ls passes through the opening periphery 52. ​​The amount of misalignment L is then calculated using the following equation: L=(La+Lb) / 2-La That is, the position where the dimensions of the pair of gaps 53a, 53b are equal is taken as the reference position S, and the positional deviation amount L is a signed positional deviation amount of the substrate W in the positional deviation direction D from this reference position S. In this way, the robot control device 15 calculates the positional deviation amount L of the substrate W from the reference position S based on the dimensions of the pair of gaps 53a, 53b between the pair of ends We1, We2 and the environment.

[0030] FIG. 5 is a diagram showing a state in which the indication point P of the hand 12 is located at the correction confirmation position Pxa.

[0031] 5, the robot control device 15 corrects the movement path T and the target position Py based on the positional deviation amount L. Specifically, the robot control device 15 calculates a corrected movement path Ta by moving (shifting) the movement path T from the confirmation position Px to the target position Py by −L in the positional deviation direction D.

[0032] Next, the robot control device 15 resumes the movement of the hand 12 that was temporarily stopped, and moves (shifts) the hand 12 by the positional deviation amount L in the positional deviation direction D so that the indication point P of the hand 12 is positioned at the correction confirmation position Pxa, which is the starting point of the corrected movement path Ta. As a result, the position of the substrate W is compensated in the positional deviation direction D so that the center C of the substrate W coincides with the confirmation position Px.

[0033] Next, the robot control device 15 moves the hand 12 on the correction movement path Ta and positions the hand 12 at the correction target position Pya, which is the end point of the correction movement path Ta. As described above, the posture of the hand 12 at the correction target position Pya is a posture that maintains the posture of the hand 12 at the correction confirmation position Pxa, so that it is possible to prevent the substrate W from shifting position again.

[0034] As described above, the substrate transport device 1 of the substrate processing equipment 100 can measure, at the confirmation position Px, the positional deviation L of the substrate W that occurs when the carrier 110 is transferred, when the substrate W is transported by the substrate transport device 1, etc., and the positional deviation L of the substrate W that occurs due to low repeatability of the substrate transport device 1, without moving the substrate W. This makes it possible to make the substrate transport device that can detect the positional deviation of the substrate W compact. Furthermore, the configuration for measuring the positional deviation L of the substrate W from the reference position S can be simplified, which is advantageous for manufacturing and reduces manufacturing costs.

[0035] Then, the robot control device 15 may correct the target position Py based on the positional deviation amount L. This makes it possible to compensate for the positional deviation of the substrate W from the substrate placement position Pp in the positional deviation direction D.

[0036] Furthermore, the hand 12 may be allowed to be misaligned in the misalignment direction D from the reference position S, and the robot control device 15 may calculate the amount of misalignment L of the substrate W from the reference position S based on the dimensions of a pair of gaps 53 between a pair of ends of the substrate W and the environment in the misalignment direction D captured in the image G. This allows the amount of misalignment L of the substrate W from the reference position S to be measured appropriately.

[0037] Furthermore, the reference position S may be a position where the dimensions of the pair of gaps 53 are equal to each other at the check position Px. This allows the amount of positional deviation L of the substrate W from the reference position S to be measured appropriately.

[0038] The environment may also be the opening periphery 52 of the gate 5 of the substrate processing equipment 100 through which the substrate W moving on the movement path passes. This allows the positional deviation L of the substrate W from the reference position S to be measured appropriately.

[0039] <Modification> In the above embodiment, the camera 6 is attached to the gate 5, but this is not limiting. Alternatively, the camera 6 may be attached to a wrist 24, as shown in FIG.

[0040] Furthermore, in the above embodiment, the hand 12 is stopped temporarily at the confirmation position Px to measure the positional deviation of the substrate W, but this is not limited to this. Instead, the robot control device 15 may measure the positional deviation based on the image G at the time when the indication point P passes the confirmation position Px while moving the hand 12. Then, the robot control device 15 may compensate for the positional deviation of the substrate W near the substrate placement position Pp based on the measurement result.

[0041] Furthermore, in the above embodiment, the positional deviation of the substrate W in the direction perpendicular to the positional deviation direction D in the horizontal plane is not compensated for, but may be compensated for. For example, the positional deviation of the substrate W in the direction perpendicular to the positional deviation direction D in the horizontal plane may be compensated for based on the image G captured by the camera 6, which is a stereo camera.

[0042] Furthermore, in the above embodiment, the amount of misalignment L was measured based on the dimension of the gap 53, but this is not limiting. For example, an image may be taken so that the substrate W and the stage 32 positioned at a predetermined position are simultaneously included in the image, and the amount of misalignment L may be measured based on the positional relationship between the substrate W and the stage 32 shown in this image.

[0043] From the above description, many modifications and other embodiments of the present invention will be apparent to those skilled in the art. Therefore, the above description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode for carrying out the present invention. Details of the structure and / or function thereof may be substantially changed without departing from the spirit of the present invention. [Explanation of symbols]

[0044] G Image L position deviation amount Px confirmation position Py target position S reference position T Travel Route W substrate 1. Substrate transport device 6. Camera 10. Robot 11 Arm 12 hands 15 Robot control device

Claims

1. A substrate transport device, a robot including a hand for holding a substrate and an arm for moving the hand; a robot control device that sets a movement path of the hand and controls the arm so that the hand moves along the movement path toward a target position; a camera provided on the hand so as to be able to photograph the moving direction of the hand, and which photographs the substrate held by the hand positioned at a predetermined confirmation position and a predetermined environment surrounding the substrate; The robot control device sets the movement path so that it passes through the confirmation position, acquires an image taken by the camera when the hand is positioned at the confirmation position, calculates the distance between the substrate shown in the image and the specified environment, and calculates the amount of positional deviation of the substrate from a reference position based on the distance.

2. The substrate transport apparatus according to claim 1 , wherein the camera is a stereo video camera that captures stereoscopic images of the substrate and the environment.

3. The substrate transport device according to claim 1 , wherein the robot control device corrects the target position based on the amount of positional deviation.

4. the hand allows positional deviation in a positional deviation direction from the reference position, 4. The substrate transport device according to claim 1, wherein the robot control device calculates the amount of positional deviation of the substrate from the reference position based on the dimensions of a pair of gaps between a pair of ends of the substrate in the positional deviation direction captured in the image and the environment.

5. The substrate transfer apparatus according to claim 4 , wherein the reference position is a position where the dimensions of the pair of gaps are equal to each other at the check position.

6. The substrate transport device according to claim 1 , wherein the environment is a periphery of an opening of a gate of a substrate processing facility through which the substrate moving on the movement path passes.

7. Set the route to pass through the designated check point, a hand of a substrate transport device that holds a substrate, the hand moving on the movement path, when positioned at the confirmation position, is provided with a camera that can capture an image of the moving direction of the hand, and an image is acquired; Calculating a distance between the substrate shown in the image and a predetermined environment surrounding the substrate; A substrate positional deviation measuring method, which calculates the amount of positional deviation from a reference position of the substrate based on the distance.

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