Substrate transport device and substrate misalignment 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 transfer device and a method for measuring substrate misalignment.

Background Art

[0002] Conventionally, an automatic substrate alignment device has been known. For example, the automatic substrate alignment device of 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 in a position symmetric with respect to the transfer direction of the substrate, such that the peripheral edge 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 output 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 enlarged.

Means for Solving the Problems

[0005] To solve the above problems, a substrate transport device according to one aspect of the present invention comprises a robot having a hand for holding a substrate and an arm for moving 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 positioned to photograph the substrate held by the hand at a predetermined confirmation position. 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 at the confirmation position, calculates the distance between the substrate shown in the image and a predetermined environment, and calculates the amount of displacement of the substrate from a reference position based on the distance.

[0006] This configuration allows for the measurement of the substrate's misalignment at the verification point, and enables the substrate transport device, which can compensate for the substrate's misalignment, to be made more compact. [Effects of the Invention]

[0007] This invention has the effect of making substrate transport devices more compact. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view showing an example configuration of a substrate processing facility equipped with a substrate transport device according to an embodiment. [Figure 2] Figure 1 is a plan view showing an example of the configuration of a substrate processing facility. [Figure 3] Figure 1 is a plan view showing an example of the operation of the substrate processing equipment, illustrating the state in which the hand is positioned in the confirmation position. [Figure 4] Figure 1 shows an example of the operation of the substrate processing equipment, and is a diagram showing an image taken by a camera of a hand positioned at the inspection location. [Figure 5] Figure 1 is a plan view showing an example of the operation of the substrate processing equipment, with the hand's movement path modified. [Figure 6] This figure shows a modified example of the substrate transport device shown in Figure 1. [Modes for carrying out the invention]

[0009] The embodiments will be described below with reference to the drawings. However, the present invention is not limited to the embodiments described below. Furthermore, throughout the following drawings, the same or corresponding elements are denoted by the same reference numerals, and redundant descriptions thereof are omitted.

[0010] Figure 1 is a perspective view showing an example configuration of a substrate processing facility 100 equipped with a substrate transport device 1 according to an embodiment. Figure 2 is a plan view showing an example configuration of the substrate processing facility 100.

[0011] As shown in Figures 1 and 2, the substrate processing equipment 100 is equipment for performing various process treatments on the 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 include silicon wafers, sapphire (single crystal alumina) wafers, and various other wafers. The substrate W may also be a glass substrate, and examples of glass wafers include glass substrates for FPDs (Flat Panel Displays) and glass substrates for MEMS (Micro Electro Mechanical Systems).

[0012] The substrate processing equipment 100 comprises a chamber 3 and a transport chamber 4, with chamber 3 connected to transport chamber 4 via a gate 5. A substrate transport device 1 is installed in the transport chamber 41 of transport chamber 4. Multiple substrates W are transported to the substrate processing equipment 100 in carriers 110 called FOUPs (Front Opening Unified Pods) and connected to transport chamber 4. The substrate transport device 1 then removes the substrates W from the carriers 110 and transfers them through the transport chamber 41 of transport chamber 4 to the substrate placement position Pp in chamber 31 of chamber 3. At the substrate placement position Pp, for example, a stage 32 for placing the substrates W is provided. Chamber 31 is, for example, a processing chamber for performing various process treatments on the substrates W, or a transport chamber for transporting the substrates W to another chamber 3. The substrates W being transported from transport chamber 4 to chamber 3 pass through the opening 51 of the gate 5, which is located between chamber 31 of chamber 3 and transport chamber 41 of transport chamber 4. Gate 5 separates room 31 and transport room 41. The opening 51 opens toward room 31 and transport room 41 and is a passage connecting room 31 and transport room 41. The periphery 52 of this opening 51 is formed, for example, in the shape of a roughly elongated rectangle, and the opening 51 has a width dimension larger than the diameter of the substrate W. In addition, the substrate placement position Pp is positioned on a straight line extending from gate 5 in the depth direction of room 31 in a plan view. This allows the substrate W to be positioned at the substrate placement position Pp by inserting it straight from gate 5 (specifically the confirmation position Px described later).

[0013] The substrate W, after being transferred to the substrate placement position Pp, undergoes predetermined processing in the chamber 3, etc. Then, it is transferred from the substrate placement position Pp to the carrier 110 by the substrate transport device 1 and stored again in the carrier 110. To prevent the adhesion of particles to the substrate W during these processes, the substrate processing equipment 100 includes devices (not shown) to maintain a high level of cleanliness in the room 31 and the transport room 41. The gate 5 also functions as a partition to maintain a high level of cleanliness on the chamber 3 side.

[0014] The substrate transfer device 1 is a device for transferring the 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 through 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 is connected to the upper end of the lifting shaft 20 via a joint so as to be rotatable around a rotation axis extending in the vertical direction. The upper arm 22 is connected to the tip end of the lower arm 21 via a joint so as to be rotatable around a rotation axis extending in the vertical direction. And the list 24 is connected to the tip end of the upper arm 22 via a joint so as to be rotatable around a rotation axis extending in the vertical direction.

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

[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. 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 modify 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 for distributed control that cooperate with each other. 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] Camera 6 is, for example, a stereo video camera capable of capturing three-dimensional images of an object. Camera 6 is used to detect misalignment of the substrate W. Camera 6 is positioned to capture images of the substrate W held by the hand 12 located at the confirmation position Px. In this embodiment, camera 6 is mounted below the opening 51 on the side of the gate 5 on the transport chamber 41 side, so that it can simultaneously capture images of the substrate W held by the hand 12 at the confirmation position Px and the opening 51. Camera 6 is angled upward so that its field of view includes the periphery 52 of the opening 51. This suppresses reflected light from the surface of the substrate W that appears in the captured image G, allowing for accurate image processing. Furthermore, by positioning camera 6 on the underside of the substrate W, particle adhesion to the upper surface of the substrate W can be prevented. The image G captured by camera 6 is input to the robot control device 15. Note that camera 6 may be a general-purpose camera used for purposes other than detecting misalignment of the substrate W. Furthermore, since camera 6 is a stereo video camera capable of capturing three-dimensional images of an object, it is possible to obtain the distance between camera 6 and the substrate W.

[0023] [Example of operation] Next, we will explain an example of the operation of the substrate transport device 1.

[0024] As shown in Figure 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 transported from the carrier 110.

[0025] Figure 3 shows the state where the indicator point P of the hand 12 is located at the confirmation position Px. In Figure 3, an example is shown where the center C of the substrate W is offset from the indicator 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 instruction point P of the hand 12 holding the substrate W moves along the movement path T toward the confirmation position Px, which is an intermediate point. Then, as shown in Figure 3, when the instruction point P of the hand 12 is located at the confirmation position Px, the robot control device 15 stops the hand 12.

[0027] Figure 4 shows an image G captured by camera 6 of hand 12 located at confirmation position Px.

[0028] Next, the robot control device 15 acquires an image G captured by the camera 6 when the instruction point P of the hand 12 is located at the confirmation position Px. Then, as shown in Figure 4, the robot control device 15 calculates the distance between the substrate W shown in the image G and the substrate transport device 1 and a predetermined environment surrounding the substrate W, and calculates the amount of displacement 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 vertically from the opening periphery 52. ​​The robot control device 15 calculates the dimension of the gap 53 between the substrate W and the opening periphery 52 adjacent to it, and calculates the amount of displacement L of the substrate W from the reference position S based on the dimension of the gap 53. Note that the displacement of the substrate W may be due to a displacement of the hand 12. The displacement of the hand 12 may occur, for example, due to the low repeatability of the robot 10.

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

[0030] Figure 5 shows the state where the instruction point P of the hand 12 is located at the correction confirmation position Pxa.

[0031] Next, as shown in Figure 5, the robot control device 15 corrects the movement path T and target position Py based on the positional displacement L. Specifically, the robot control device 15 calculates a corrected movement path Ta by shifting the movement path T from the confirmation position Px to the target position Py by -L in the positional displacement direction D.

[0032] Next, the robot control device 15 resumes the movement of the hand 12, which had been temporarily stopped, and shifts the hand 12 by a displacement amount L in the displacement direction D so that the instruction point P of the hand 12 is located at the corrected 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 so that the center C of the substrate W coincides with the confirmation position Px in the displacement direction D.

[0033] Next, the robot control device 15 moves the hand 12 along the correction movement path Ta, positioning the hand 12 at the correction target position Pya, which is the end point of the correction movement path Ta. As mentioned above, the posture of the hand 12 at the correction target position Pya is the same as the posture of the hand 12 at the correction confirmation position Pxa, thus preventing the substrate W from shifting position again.

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

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

[0036] Furthermore, the hand 12 may allow a positional displacement in the displacement direction D from the reference position S, and the robot control device 15 may calculate the amount of positional displacement L of the substrate W from the reference position S based on the dimensions of a pair of gaps 53 between a pair of edges of the substrate W and the environment in the displacement direction D shown in the image G. This allows for appropriate measurement of the amount of positional displacement L of the substrate W from the reference position S.

[0037] Furthermore, the reference position S may be a position at the verification position Px where the dimensions of the pair of gaps 53 are equal. This allows for accurate measurement of the displacement L of the substrate W from the reference position S.

[0038] Furthermore, the environment may also be the peripheral edge 52 of the opening 5 of the gate 5 of the substrate processing equipment 100 through which the substrate W moving along the movement path passes. This allows for the appropriate measurement of the displacement L of the substrate W from the reference position S.

[0039] <Variation> In the above embodiment, the camera 6 was attached to the gate 5, but it is not limited to this. Alternatively, as shown in Figure 6, the camera 6 may be attached to the listing 24.

[0040] Furthermore, in the above embodiment, the hand 12 was temporarily stopped at the confirmation position Px to measure the displacement of the substrate W, but this is not the only method. Alternatively, the robot control device 15 may measure the displacement based on the image G taken when the instruction point P passes the confirmation position Px while moving the hand 12. The robot control device 15 may then compensate for the displacement of the substrate W near the substrate mounting position Pp based on the measurement results.

[0041] Furthermore, in the above embodiment, the misalignment of the substrate W in a direction perpendicular to the misalignment direction D in the horizontal plane is not compensated for, but this may be compensated for. For example, the misalignment of the substrate W in a direction perpendicular to the misalignment 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 dimensions of the gap 53, but this is not the only way. For example, the substrate W positioned at a predetermined location and the stage 32 may be photographed so that they are both in the same image, and the amount of misalignment L may be measured based on the positional relationship between the substrate W and the stage 32 as seen 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 interpreted as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of its structure and / or function can be substantially modified without departing from the spirit of the invention. [Explanation of symbols]

[0044] G Image L Positional displacement Px confirmation position Py target position S reference position T Travel Path W board 1. Substrate transport device 6 cameras 10 Robots 11 Arms 12 Hands 15 Robot control device

Claims

1. A substrate transport device, A substrate transport unit comprising a blade for holding a substrate and a hand including a wrist connected to the base end of the blade, and an arm connected to the base end of the wrist, A 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, The substrate transport unit is equipped with a camera that moves together with the substrate transport unit and is positioned at a predetermined confirmation location, which is held by the hand and takes pictures of the substrate and the predetermined environment surrounding the substrate. A substrate transport device comprising: a control device which 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, and calculates the amount of positional deviation of the substrate from a reference position based on the distance between the substrate and the predetermined environment shown in the image.

2. The substrate transport apparatus according to claim 1, wherein the camera is provided in the list.

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

4. The substrate transport apparatus according to any one of claims 1 to 3, wherein the control device corrects the target position based on the amount of positional deviation.

5. The hand allows for a positional displacement in the direction of displacement from the reference position, The substrate transport apparatus according to any one of claims 1 to 4, wherein the control device calculates the amount of displacement of the substrate from the reference position based on the dimensions of a pair of gaps between a pair of ends of the substrate and the environment in the displacement direction shown in the image.

6. The substrate transport apparatus according to claim 5, wherein the reference position is a position in the confirmation position where the dimensions of a pair of gaps are equal to each other.

7. The substrate transport apparatus according to any one of claims 1 to 6, wherein the environment is the periphery of the opening of the gate of a substrate processing facility through which the substrate moving along the movement path passes.

8. Set a travel path so that it passes through the designated confirmation location. A hand for a substrate transport device that holds a substrate, wherein when the hand moving along the movement path is positioned at the confirmation position, a camera is provided to capture an image of the direction of travel of the hand, and the image is acquired. A substrate displacement measurement program that calculates the amount of displacement of the substrate from a reference position based on the distance between the substrate and a predetermined environment surrounding the substrate as shown in the aforementioned image.

Images