Substrate Transfer Device and Substrate Position Deviation Measurement Method

Abstract

To provide a compact substrate transfer apparatus and a method of measuring positional deviation of a substrate.SOLUTION: A substrate transfer apparatus 1 installed in a conveyance room of a conveyance chamber in a substrate processing facility 100 having a chamber 3 and the conveyance chamber includes: a robot 10 including a hand 12 configured to hold a substrate W, and an arm 11 configured to move the hand 12; a robot control device 15 configured to set a moving path for the hand 12 and control the arm 11 such that the hand 12 moves on the moving path toward a target position; and a camera 6 disposed so as to be able to capture an image of the substrate W held by the hand 12 located at a predetermined confirmation position. The robot control device 15 sets the moving path so as to pass through the confirmation position, obtains an image captured by the camera 6 when the hand 12 is located at the confirmation position, calculates a distance between a predetermined environment and the substrate W which are taken in the image, and calculates a positional deviation amount from a reference position of the substrate W on the basis of the distance.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a substrate transfer device and a method for measuring substrate misalignment.

Background Art

[0002] Conventionally, an automatic alignment device for substrates has been known. For example, the automatic alignment device for substrates in Patent Document 1 includes two sensors, two light sources, and a transfer chuck for transferring the substrate. The sensors and the light sources are installed above and below the substrate, and at positions symmetric with respect to the transfer direction of the substrate, such that the peripheral portion of the substrate crosses between the two sensors and the light sources. Then, the transfer chuck sucks and fixes the substrate and moves it, calculates the center position of the substrate based on the sensor outputs when the two sensors are shaded, and calculates the amount of deviation from the reference point coordinates of the substrate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the automatic alignment device described in Japanese Patent Application Laid-Open No. 63-94653 has a problem that when calculating the amount of misalignment, it is necessary to move the substrate significantly in a straight line in the transfer direction, and the device tends to be large-sized.

Means for Solving the Problems

[0005] To solve the above problems, a substrate transfer device according to an aspect of the present invention includes a robot including a hand that holds a substrate and an arm that moves the hand, a robot control device that sets a movement path of the hand and controls the arm so that the hand moves toward a target position on the movement path, and a camera disposed so as to be able to photograph the substrate held by the hand located at a predetermined confirmation position. The robot control device sets the movement path so as to pass through the confirmation position, acquires an image captured by the camera when the hand is located at the confirmation position, calculates a distance between the substrate shown in the image and a predetermined environment, and calculates an amount of displacement of the substrate from a reference position based on the distance.

[0006] According to this configuration, it is possible to measure the displacement of the substrate at the confirmation position, and it is possible to make the substrate transfer device that can compensate for the displacement of the substrate compact.

Effect of the Invention

[0007] The present invention has an effect that the substrate transfer device can be made compact.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments will be described with reference to the drawings. Note that the present invention is not limited by the following embodiments. Also, in the following, throughout all the drawings, the same or corresponding elements are denoted by the same reference numerals, and the overlapping descriptions thereof are omitted.

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

[0011] As shown in FIGS. 1 and 2, the substrate processing facility 100 is a facility for performing various processings such as heat treatment, impurity introduction processing, thin film formation processing, lithography processing, cleaning processing, and planarization processing on a substrate W. In the present 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. Note that the substrate W may be a glass substrate, and examples of the glass wafer include a glass substrate for FPD (Flat Panel Display) and a glass substrate for MEMS (Micro Electro Mechanical Systems).

[0012] And the substrate processing equipment 100 includes a chamber 3 and a transfer chamber 4. The chamber 3 is connected to the transfer chamber 4 via a gate 5. A substrate transfer device 1 is installed in the transfer chamber 41 of the transfer chamber 4. The substrate W is transferred to the substrate processing equipment 100 in a state where a plurality of substrates are accommodated in a carrier 110 called a FOUP (Front Opening Unified Pod), and is connected to the transfer chamber 4. Then, the substrate transfer device 1 takes out the substrate W accommodated in the carrier 110 and transfers it to the substrate placement position Pp in the room 31 of the chamber 3 through the transfer chamber 41 of the transfer chamber 4. At the substrate placement position Pp, for example, a stage 32 for placing the substrate W is provided. The room 31 is, for example, a processing chamber for performing various processings on the substrate W, or a transfer chamber for transferring the substrate W to another chamber 3. And the substrate W carried into the chamber 3 from the transfer chamber 4 passes through the 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 partitions the room 31 and the transfer chamber 41. The opening 51 opens toward the room 31 and the transfer chamber 41 and is a passage connecting the room 31 and the transfer chamber 41. The peripheral edge 52 of the opening 51 is formed, for example, in a substantially horizontally long rectangular shape, and the opening 51 has a width dimension larger than the diameter of the substrate W. Also, the substrate placement position Pp is positioned on a straight line extending in the depth direction of the room 31 from the gate 5 in a plan view. Thereby, the substrate W can be positioned at the substrate placement position Pp by inserting the substrate W straight from the gate 5 (specifically, a confirmation position Px described later).

[0013] And the substrate W transferred to the substrate placement position Pp is subjected to predetermined processing in the chamber 3 or the like. Then, the substrate transfer device 1 transfers the substrate from the substrate placement position Pp to the carrier 110 and accommodates it in the carrier 110 again. To prevent the adhesion of particles to the substrate W in these processes, the substrate processing equipment 100 includes a device (not shown) for keeping the cleanliness of the room 31 and the transfer chamber 41 high. Also, the gate 5 functions as a partition wall for keeping the cleanliness on the chamber 3 side high.

[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 scalar-type horizontal articulated robot. The robot 10 is moved three-dimensionally by the arm 11, that is, in three axial directions orthogonal to each other. The robot 10 includes a base 14 installed in the transfer chamber 41, an arm 11, a hand 12, and an arm drive unit 13.

[0016] The hand 12 is a passive hand and includes a blade 23 and a list 24 connected to the base end of the blade 23. The blade 23 is flat as a whole and is held by the arm 11 so that its upper surface remains horizontal. Then, the blade 23 holds the substrate W placed thereon by frictional force via three pads 23a provided on the upper surface. Note that the hand 12 is not limited to a passive hand, and may be a suction hand that sucks and holds the substrate W 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 a plurality of joints, with its base end connected to the base 14 and its tip end connected to the list 24. The arm 11 includes a plurality of links (lifting shaft 20, lower arm 21, upper arm 22) 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 its base end connected to the upper end of the lifting shaft 20 so as to be rotatable around a rotation axis extending in the vertical direction via a joint. The upper arm 22 has its base end connected to the tip end of the lower arm 21 so as to be rotatable around a rotation axis extending in the vertical direction via a joint. And the list 24 has its base end connected to the tip end of the upper arm 22 so as to be rotatable around a rotation axis extending in the vertical direction via a joint.

[0019] The arm drive unit 13 is a mechanism that rotates the lower arm 21, the upper arm 22, and the blade 23 at the joints to move the hand 12 in the horizontal direction. Further, the arm drive unit 13 is a mechanism that moves the entire arm 11 in the vertical direction by raising and lowering the lifting shaft 20, and moves the hand 12 in the vertical direction.

[0020] The robot control device 15 sets the movement path T of the instruction point P according to a predetermined operation program. In the present embodiment, the movement path T includes a path for the hand 12 to pick up the substrate W to be conveyed on the carrier 110, and then, the instruction point P passes through the confirmation position Px and reaches the target position Py. The instruction 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 posture of the hand 12 at the confirmation position Px is maintained. Then, the robot control device 15 controls the arm 11 so that the instruction point P of the hand 12 moves on the movement path T toward the target position Py. Note that the information related to the movement path T includes not only information defining the displacement of the position of the hand 12 but also information defining the displacement of the posture of the hand 12. Similarly, the confirmation position Px and the target position Py also include information defining the posture of the hand 12. And 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 an arithmetic unit such as a CPU and a storage unit having a memory such as a ROM and a RAM. The control unit may be composed of a single controller for centralized control or may be composed of a plurality of controllers that cooperate with each other for distributed control. A program for generating the movement path T is stored in the storage unit, and the arithmetic 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 three-dimensionally imaging an object. The camera 6 is used to detect the positional deviation of the substrate W. Also, the camera 6 is arranged so as to be able to photograph the substrate W held by the hand 12 located at the confirmation position Px. In the present embodiment, the camera 6 is attached at a position corresponding to below the opening 51 on the side surface of the conveyance chamber 41 side of the gate 5, and can simultaneously photograph the substrate W held by the hand 12 located at the confirmation position Px and the opening 51. And the camera 6 is directed obliquely upward so as to include the opening edge 52 of the opening 51 in the visual field. Thereby, the reflected light on the surface of the substrate W reflected in the photographed image G can be suppressed, and image processing can be accurately performed. Also, by positioning the camera 6 on the lower surface side of the substrate W, adhesion of particles to the upper surface of the substrate W can be prevented. Then, the image G photographed by the camera 6 is input to the robot control device 15. Note that the camera 6 may be a general-purpose camera used for purposes other than detecting the positional deviation of the substrate W. Also, since the camera 6 is a stereo video camera capable of three-dimensionally imaging an object, the distance between the camera 6 and the substrate W can be obtained.

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

[0024] As shown in FIG. 2, first, the robot control device 15 sets the 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 transferred in the carrier 110.

[0025] FIG. 3 is a diagram showing a state where the indicated point P of the hand 12 is located at the confirmation position Px. In FIG. 3, an example is shown in which the center C of the substrate W is deviated from the indicated 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 to move on the movement path T toward the confirmation position Px where the instruction point P of the hand 12 holding the substrate W is the passing point. Then, as shown in FIG. 3, when the instruction point P of the hand 12 is positioned at the confirmation position Px, the robot control device 15 temporarily stops the hand 12.

[0027] FIG. 4 is a diagram showing an image G obtained by the camera 6 photographing the hand 12 positioned at the confirmation position Px.

[0028] Next, when the instruction point P of the hand 12 is positioned at the confirmation position Px, the robot control device 15 acquires the image G photographed by the camera 6. Then, as shown in FIG. 4, the robot control device 15 calculates the distance between the substrate W shown in the image G, the substrate transfer device 1, and the predetermined environment surrounding the substrate W, and calculates the amount of displacement L from the reference position S of the substrate W based on this distance. In the present embodiment, the predetermined environment is the opening edge 52, and more specifically, the left and right side edges extending in the vertical direction of the opening edge 52. The robot control device 15 calculates the dimension of the gap 53 between the substrate W and the adjacent opening edge 52, and calculates the amount of displacement L from the reference position S of the substrate W based on the dimension of the gap 53. Note that the displacement of the substrate W may be caused by the displacement of the hand 12. The displacement of the hand 12 is caused, for example, by the low repetitive accuracy of the robot 10.

[0029] Specifically, the robot control device 15 calculates a dimension La of a first gap 53a between the 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 between the 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 extending in the misalignment direction D passing 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 misalignment amount L is calculated using the following formula. 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 manner, 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 check position Pxa.

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

[0032] Next, the robot control device 15 resumes the movement of the hand 12 that was temporarily stopped, and moves (shifts) the indication point P of the hand 12 by the positional deviation amount L in the positional deviation direction D so that it is positioned at the correction confirmation position Pxa, which is the start point of the corrected movement path Ta. This compensates the position of the substrate W 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 along the corrected movement path Ta and positions the hand 12 at the corrected target position Pya which is the end point of the corrected movement path Ta. As described above, since the posture of the hand 12 at the corrected target position Pya is the posture maintaining the posture of the hand 12 at the corrected confirmation position Pxa, it is possible to prevent the positional deviation of the substrate W from occurring again.

[0034] As described above, the substrate transfer device 1 of the substrate processing facility 100 can measure, at the confirmation position Px, without moving the substrate W, the positional deviation of the substrate W caused by the transfer of the carrier 110, the transfer of the substrate W by the substrate transfer device 1, etc., and the amount of positional deviation L of the substrate W caused by the low repetitive accuracy of the substrate transfer device 1. As a result, it is possible to make the substrate transfer device capable of detecting the positional deviation of the substrate W compact. In addition, the configuration for measuring the amount of positional deviation L of the substrate W from the reference position S of the substrate W can be simplified, which is advantageous for manufacturing and also reduces the manufacturing cost.

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

[0036] Further, the hand 12 allows the positional deviation in the positional deviation direction D from the reference position S, and the robot control device 15 calculates the amount of positional deviation L of the substrate W from the reference position S of the substrate W based on the dimensions of a pair of gaps 53 between a pair of end portions of the substrate W and the environment in the positional deviation direction D shown in the image G. Thereby, the amount of positional deviation L of the substrate W from the reference position S can be appropriately measured.

[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 confirmation position Px. Thereby, the amount of positional deviation L of the substrate W from the reference position S can be appropriately measured.

[0038] Further, the environment may be the peripheral edge 52 of the opening of the gate 5 of the substrate processing facility 100 through which the substrate W moving on the moving path passes. Thereby, the amount of displacement L of the substrate W from the reference position S can be appropriately measured.

[0039] <Modification> In the above embodiment, the camera 6 was attached to the gate 5, but it is not limited thereto. Instead, as shown in FIG. 6, the camera 6 may be attached to the list 24.

[0040] Also, in the above embodiment, the hand 12 was once stopped at the confirmation position Px to measure the displacement of the substrate W, but it is not limited thereto. Instead, the robot control device 15 may measure the displacement based on the image G when the instruction point P passes through the confirmation position Px while moving the hand 12. Then, the robot control device 15 may compensate for the displacement of the substrate W near the substrate placement position Pp based on the measurement result.

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

[0042] Also, in the above embodiment, the amount of displacement L was measured based on the dimension of the gap 53, but it is not limited thereto. For example, the substrate W and the stage 32 positioned at a predetermined position may be photographed so as to be included in the image at the same time, and the amount of displacement 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 improvements 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 of carrying out the present invention. Without departing from the spirit of the present invention, the details of its structure and / or function can be substantially changed.

Explanation of Reference Numerals

[0044] G Image L Amount of Misalignment Px Confirmation Position Py Target Position S Reference Position T Movement Path W Substrate 1 Substrate Conveyor 6 Camera 10 Robot 11 Arm 12 Hand 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 that is provided on the hand so as to be able to photograph a moving direction of the hand, and that photographs the substrate held by the hand located at a predetermined confirmation position and a predetermined environment surrounding the substrate; 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 the specified environment, and calculates the amount of positional deviation of the substrate from a reference position based on the distance, in a substrate transport device.

2. A substrate conveying device as described in claim 1, wherein the camera is a stereo video camera that captures images of the substrate and the environment in three dimensions.

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 a positional deviation in a positional deviation direction from the reference position, The substrate transport device according to any one of claims 1 to 3, 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 transport apparatus according to claim 4 , wherein the reference position is a position where the dimensions of a pair of gaps are equal to each other in the check position.

6. A substrate conveying device as described in any one of claims 1 to 5, wherein the environment is the periphery of the opening of a gate of substrate processing equipment through which the substrate moving on the moving path passes.

7. Set the movement route so that it passes through the specified confirmation position, a hand of a substrate transport device that holds a substrate, the hand moving on the movement path being positioned at the confirmation position, and an image captured by a camera provided on the hand capable of capturing an image of a moving direction of the hand is acquired; Calculating a distance between the substrate captured in the image and a predetermined environment surrounding the substrate; and calculating an amount of positional deviation from a reference position of the substrate based on the distance.

Images