Substrate handling device and substrate position offset measurement method

Abstract

The substrate handling apparatus (1) of the present invention comprises: a robot (10) having a hand (12) for holding a substrate (W) and an arm (11) for moving the hand (12); a robot control device (15) for setting a movement path (T) of the hand (12) and controlling the arm (11) to move the hand (12) toward a target position (Py) on the movement path (T); and a camera (6) configured to capture an image of the substrate (W) held by the hand (12) at a predetermined confirmation position (Px). The robot control device (15) sets the movement path (T) by means of confirming the position (Px), acquires an image (G) captured by the camera (6) when the hand (12) is at the confirmation position (Px), calculates the distance between the substrate (W) captured in the image (G) and a predetermined environment, and calculates the position offset (L) of the substrate (W) from the reference position (S) based on the distance.

Description

Technical Field

[0001] This invention relates to a substrate handling device and a method for measuring substrate position offset. Background Technology

[0002] Conventionally, an automatic positioning alignment device for a substrate is known. For example, the automatic positioning alignment device for a substrate in Patent Document 1 includes two sensors, two light sources, and a transport chuck for transporting the substrate. The sensors and light sources are positioned vertically and symmetrically relative to the transport direction of the substrate, with the periphery of the substrate passing through the two sensors and the light sources. Furthermore, the transport chuck attracts and fixes the substrate, causing it to move. The center position of the substrate is calculated based on the sensor output when the two sensors are blocked from light, and the offset of the substrate from the reference point coordinates is calculated based on this.

[0003] Patent Document 1: Japanese Patent Application Publication No. 63-94653

[0004] However, the automatic position alignment device described in Japanese Patent Application Publication No. 63-94653 requires the substrate to be moved significantly in a straight line in the transport direction when calculating the position offset, which makes the device prone to large-scale manufacturing. Summary of the Invention

[0005] To address the aforementioned issues, one aspect of the present invention relates to a substrate handling apparatus comprising: 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 to move the hand toward a target position along the movement path; and a camera configured to capture an image of the substrate held by the hand at a predetermined confirmation position. The robot control device sets the movement path by means of the confirmation position, acquires an image captured by the camera when the hand is at the confirmation position, calculates the distance between the substrate captured in the image and a predetermined environment, and calculates the positional offset of the substrate from a reference position based on the distance.

[0006] According to this structure, a substrate handling device that can measure the positional offset of the substrate at a confirmed location and compensate for the positional offset of the substrate can be miniaturized.

[0007] This invention enables the miniaturization of substrate handling devices. Attached Figure Description

[0008] Figure 1 This is a perspective view showing a structural example of a substrate processing apparatus equipped with the substrate handling device according to the embodiment.

[0009] Figure 2 It means Figure 1A top view of an example of the structure of a substrate processing device.

[0010] Figure 3 It means Figure 1 A top view of an example of the operation of a substrate processing device, and a diagram showing the state in which the hand is in the confirmation position.

[0011] Figure 4 It means Figure 1 The diagram shows an example of the operation of a substrate processing device, and also shows an image of a hand being photographed by a camera at a confirmed position.

[0012] Figure 5 It means Figure 1 A top view of an example of the operation of a substrate processing device, showing a state in which the movement path of the hand has been corrected.

[0013] Figure 6 It means Figure 1 A diagram showing a modified example of the substrate handling device. Detailed Implementation

[0014] Hereinafter, embodiments will be described with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments. Furthermore, in all the following figures, the same or equivalent elements will be labeled with the same reference numerals, and repeated descriptions will be omitted.

[0015] Figure 1 This is a perspective view showing a structural example of a substrate processing apparatus 100 equipped with the substrate handling device 1 according to the embodiment. Figure 2 This is a top view showing an example of the structure of the substrate processing apparatus 100.

[0016] like Figure 1 as well as Figure 2 As shown, the substrate processing apparatus 100 is used to perform various processes on the substrate W, such as heat treatment, impurity introduction treatment, thin film formation treatment, photolithography 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. Alternatively, the substrate W can also be a glass substrate, serving as a glass wafer, for example, a glass substrate for FPD (Flat Panel Display) or a glass substrate for MEMS (Micro Electro Mechanical Systems).

[0017] Furthermore, the substrate processing apparatus 100 includes a chamber 3 and a transport chamber 4, with the chamber 3 connected to the transport chamber 4 via a gate 5. A substrate transport device 1 is provided in the transport chamber 41 of the transport chamber 4. Substrates W are transported to the substrate processing apparatus 100 and connected to the transport chamber 4 while being housed in multiple carriers 110 called FOUP (Front Opening Unified Pod). Then, the substrate transport device 1 removes the substrates W housed in the carriers 110 and moves them through the transport chamber 41 of the transport chamber 4 to the substrate placement position Pp in the space 31 of the chamber 3. A stage 32 for placing the substrates W is provided at the substrate placement position Pp, for example. The space 31 is, for example, a processing chamber for performing various process treatments on the substrates W, or a transport chamber for further transporting the substrates W to another chamber 3. Then, the substrate W, transported from the transport chamber 4 to the chamber 3, passes through the opening 51 of the gate 5 located between the space 31 of the chamber 3 and the transport chamber 41 of the transport chamber 4. The gate 5 divides the space 31 and the transport chamber 41. The opening 51 is a passageway that opens towards both the space 31 and the transport chamber 41 and connects the space 31 and the transport chamber 41. The periphery 52 of the opening 51 is, for example, formed as a generally transversely elongated quadrilateral, and the opening 51 has a width dimension larger than the diameter of the substrate W. Furthermore, the substrate placement position Pp, when viewed from above, is positioned on a straight line extending from the gate 5 toward the depth direction of the space 31. Thus, the substrate W can be positioned at the substrate placement position Pp by inserting it more vertically from the gate 5 (specifically, the confirmation position Px described later).

[0018] Then, the substrate W, transferred to the substrate placement position Pp, is subjected to a predetermined treatment 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 is again housed in the carrier 110. To prevent particles from adhering to the substrate W during the above process, the substrate processing apparatus 100 includes a device (not shown) for maintaining a high level of cleanliness in the space 31 and the transport chamber 41. Additionally, the gate 5 functions as a partition wall for maintaining a high level of cleanliness on the chamber 3 side.

[0019] The substrate handling device 1 is a device for handling substrate W, and includes a robot 10, a robot control device 15, and a camera 6.

[0020] Robot 10 is, for example, a SCARA-type horizontal articulated robot. Robot 10 moves in three dimensions, i.e., in three mutually orthogonal axes, via arm 11. Robot 10 includes a base 14 disposed in a transport chamber 41, arm 11, hand 12, and arm drive unit 13.

[0021] Hand 12 is a passive hand, comprising a support plate 23 and a wrist 24 connected to the base end of the support plate 23. The support plate 23 is generally flat and is held horizontally by the arm 11. Then, the support plate 23 holds the substrate W placed thereon by friction through three pads 23a provided on its upper surface. In addition, hand 12 is not limited to a passive hand, and can also be an adsorption hand that attracts and holds the substrate W in workpieces such as a Bernoulli hand, or an edge gripping hand that holds the edge of the substrate W.

[0022] Arm 11 is a multi-joint structure containing multiple joints, with its base end connected to base 14 and its front end connected to wrist 24. Arm 11 has multiple links (lifting shaft 20, lower arm 21, upper arm 22) that are sequentially connected via joints in the direction from the base end toward the front end.

[0023] The lifting shaft 20 is connected in a manner that allows it to move vertically relative to the base 14. The lower arm 21 is connected to the upper end of the lifting shaft 20 such that its base end can rotate about a rotation axis extending vertically via a joint. The upper arm 22 is connected to the front end of the lower arm 21 such that its base end can rotate about a rotation axis extending vertically via a joint. Furthermore, the wrist 24 is connected to the front end of the upper arm 22 such that its base end can rotate about a rotation axis extending vertically via a joint.

[0024] The arm drive unit 13 is a mechanism that rotates the lower arm 21, upper arm 22, and support plate 23 in the joint to move the hand 12 in the horizontal direction. In addition, the arm drive unit 13 is a mechanism that moves the arm 11 as a whole in the vertical direction by raising and lowering the lifting shaft 20, and also moves the hand 12 in the vertical direction.

[0025] The robot control device 15 sets the movement path T of the indicator point P according to a predetermined action procedure. In this embodiment, the movement path T is a path that includes the action of the hand 12 lifting the substrate W of the transport object in the carrier 110, and then the indicator point P moves from the confirmation position Px to the target position Py. The indicator point P is, for example, set on the central axis of a circle defined by the points where the three pads 23a of the tray 23 are located. The confirmation position Px is, for example, set at the center of the opening 51. Furthermore, at the confirmation position Px, the hand 12 can also adopt a posture extending towards the target position Py. The target position Py is set at the center of the substrate placement position Pp, where the hand 12 maintains the posture at the confirmation position Px. Then, the robot control device 15 controls the arm 11 to move the indicator point P of the hand 12 towards the target position Py along the movement path T. Furthermore, the information involved in the movement path T includes not only information defining the displacement of the hand 12's position, but also information defining the displacement of the hand 12's posture. The confirmed position Px and the target position Py also include information defining the posture of the hand 12. Furthermore, the robot control device 15 is configured to correct the movement path T.

[0026] The robot control unit 15 includes, for example, a control unit with an arithmetic logic unit (ALU) such as a CPU, and a storage unit with memory such as ROM and RAM. The control unit can be composed of a single controller for centralized control, or it can be composed of multiple controllers that cooperate to perform distributed control. The storage unit stores a program for generating a movement path T, and the ALU executes the program to control the position and posture of the hand 12.

[0027] Camera 6 is, for example, a stereo camera capable of capturing images of an object in three dimensions. Camera 6 is used to detect positional shifts in the substrate W. Furthermore, camera 6 is configured to capture images of the substrate W held by hand 12 at the confirmation position Px. In this embodiment, camera 6 is mounted below the opening 51 on the side of the gate 5's transport chamber 41 side, allowing simultaneous capture of the substrate W held by hand 12 at the confirmation position Px and the opening 51. Moreover, camera 6 is angled upwards so that the periphery 52 of the opening 51 is included in the field of view. This suppresses reflected light from the surface of the substrate W into which the captured image G is projected, enabling precise image processing. Additionally, by positioning camera 6 on the lower surface of substrate W, adhesion of particles to the upper surface of substrate W is prevented. The image G captured by camera 6 is input to robot control device 15. Furthermore, camera 6 can also be a general-purpose camera for purposes other than detecting positional shifts in substrate W. Furthermore, since camera 6 is a stereo camera capable of capturing images of an object in three dimensions, the distance between camera 6 and substrate W can be obtained.

[0028] [Action Example]

[0029] Next, an example of the operation of the substrate handling device 1 will be described.

[0030] like Figure 2 As shown, firstly, 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 lifts the substrate W of the object to be transported in the carrier 110.

[0031] Figure 3 This is a diagram showing the state where the indicator point P of hand 12 is located at the confirmation position Px. Figure 3 The image shows an example where the center C of the substrate W is offset from the indicator point P of the tray 23, and the substrate W is placed on the tray 23.

[0032] Next, the robot control unit 15 controls the arm 11, causing the pointer P of the hand 12 holding the substrate W to move along the movement path T toward the confirmed position Px, which is the transit point. Then, as... Figure 3 As shown, when the pointer point P of the hand 12 is located at the confirmed position Px, the robot control device 15 causes the hand 12 to temporarily stop.

[0033] Figure 4 This is a diagram showing the image G taken by camera 6 of hand 12 located at the confirmed position Px.

[0034] Next, the robot control device 15 acquires the image G captured by the camera 6 at the moment when the indicated point P on the hand 12 is located at the confirmed position Px. Then, as... Figure 4 As shown, the robot control device 15 calculates the distance between the substrate W captured in image G and the substrate transport device 1, as well as the defined environment in which the substrate W is located, and calculates the positional offset L of the substrate W from the reference position S based on this distance. In this embodiment, the defined environment refers to the periphery 52 of the opening, and more specifically, to the left and right side edges of the periphery 52 extending in the vertical direction. The robot control device 15 calculates the size of the gap 53 between the substrate W and the periphery 52 of the opening located in an adjacent position, and calculates the positional offset L of the substrate W from the reference position S based on the size of the gap 53. Furthermore, the positional offset of the substrate W can also be caused by the positional offset of the hand 12. The positional offset of the hand 12 may occur, for example, due to the low repeatability of the robot 10.

[0035] Specifically, the robot control device 15 calculates the dimensions La of the first gap 53a between the first end We1 of the substrate W, which is in the position offset direction D, and the second gap 53b between the second end We2 and the opening periphery 52, as captured in the image G. Furthermore, the position offset direction D refers to the direction in which the position offset is measured, for example, the width direction of the opening 51. Moreover, the first end We1 and the second end We2 can also be locations on a straight line Ls extending through the center C of the substrate W in the position offset direction D. Additionally, the first gap 53a can also be the gap between the first end We1 and the location where the straight line Ls passes through the opening periphery 52. ​​Similarly, the second gap 53b can also be the gap between the second end We2 and the location where the straight line Ls passes through the opening periphery 52. ​​Then, the position offset L is calculated using the following formula.

[0036] L=(La+Lb) / 2-La

[0037] That is, the position offset L is the signed position offset of the substrate W from the reference position S, which is the position where the dimensions of a pair of gaps 53a and 53b are equal. In this way, the robot control device 15 calculates the position offset L of the substrate W from the reference position S based on the dimensions of a pair of gaps 53a and 53b between the ends We1 and We2 and the environment.

[0038] Figure 5 This is a diagram showing the state where the indicator point P of hand 12 is located at the correction confirmation position Pxa.

[0039] Next, as Figure 5 As shown, the robot control device 15 corrects the movement path T and the target position Py based on the position offset L. Specifically, the robot control device 15 calculates the corrected movement path Ta after moving the movement path T from the confirmed position Px to the target position Py by a displacement of -L along the position offset direction D.

[0040] Next, the robot control device 15 restarts the movement of the temporarily stopped hand 12, moving (displacement) by a position offset L in the position offset direction D, such that the pointer point P of the hand 12 is located at the correction confirmation position Pxa, which serves as the starting point of the correction movement path Ta. Thus, in the position offset direction D, the position of the substrate W is compensated so that the center C of the substrate W coincides with the confirmation position Px.

[0041] Next, the robot control device 15 moves the hand 12 along the corrected movement path Ta, positioning the hand 12 at the corrected target position Pya, which is the endpoint of the corrected movement path Ta. Furthermore, as described above, the posture of the hand 12 at the corrected target position Pya is the same posture as that of the hand 12 at the corrected confirmation position Pxa, thus preventing the positional shift of the substrate W from occurring again.

[0042] As described above, the substrate transport device 1 of the substrate processing apparatus 100 can measure the positional shift of the substrate W caused by the transport of the substrate W by the substrate transport device 1 during the transfer of the carrier 110, and the positional shift L of the substrate W caused by the low repeatability of the substrate transport device 1, without moving the substrate W at the confirmed position Px. Therefore, the substrate transport device capable of detecting the positional shift of the substrate W can be miniaturized. Furthermore, the structure for measuring the positional shift L of the substrate W from the reference position S can be simplified, which is beneficial for manufacturing and reduces manufacturing costs.

[0043] Furthermore, the robot control device 15 can also correct the target position Py based on the position offset L. This allows for compensation of the position offset of the substrate W in the position offset direction D, originating from the substrate placement position Pp.

[0044] Furthermore, since the hand 12 allows for positional displacement from the reference position S to the positional displacement direction D, the robot control device 15 can also calculate the positional displacement L from the reference position S of the substrate W based on the dimensions of a pair of gaps 53 between a pair of ends of the substrate W in the positional displacement direction D captured in the image G and the environment. Thus, the positional displacement L of the substrate W from the reference position S can be appropriately measured.

[0045] Furthermore, the reference position S can also be a position where the dimensions of a pair of gaps 53 are equal at the confirmed position Px. Therefore, the positional offset L of the substrate W from the reference position S can be appropriately measured.

[0046] Alternatively, the environment can be the periphery 52 of the gate 5 of the substrate processing equipment 100 through which the substrate W moves along the movement path. Therefore, the positional offset L of the substrate W from the reference position S can be appropriately measured.

[0047] <Variation Example>

[0048] In the above embodiment, although the camera 6 is installed on the gate 5, it is not limited to this. It can also be replaced by, for example... Figure 6 As shown, camera 6 can also be mounted on wrist 24.

[0049] Furthermore, in the above embodiment, although the hand 12 is temporarily stopped at the confirmed position Px to measure the positional offset of the substrate W, it is not limited to this. Alternatively, the robot control device 15 can move the hand 12 while measuring the positional offset based on the image G at the moment when the indicator point P passes the confirmed position Px. Moreover, the robot control device 15 can also compensate for the positional offset of the substrate W near the substrate placement position Pp based on the measurement results.

[0050] Furthermore, in the above embodiment, the positional displacement of the substrate W in the horizontal plane in a direction orthogonal to the positional displacement direction D is not compensated, but it can be compensated. For example, the positional displacement of the substrate W in the horizontal plane in a direction orthogonal to the positional displacement direction D can be compensated based on the image G captured by the camera 6, which is a stereo camera.

[0051] Furthermore, while the position offset L is measured based on the size of the gap 53 in the above embodiment, it is not limited to this. For example, an image can be captured simultaneously of the substrate W and the stage 32 located at a predetermined position, and the position offset L can be measured based on the positional relationship between the substrate W and the stage 32 captured in the image.

[0052] Based on the foregoing description, many improvements and other embodiments of the present invention will be apparent to those skilled in the art. Therefore, the foregoing description should be interpreted as illustrative only, provided for the purpose of teaching those skilled in the art the best mode for carrying out the invention. Substantial changes can be made to the details of its structure and / or function without departing from the spirit of the invention.

[0053] Explanation of reference numerals in the attached figures

[0054] G...Image; L...Position offset; Px...Confirmed position; Py...Target position; S...Reference position; T...Movement path; W...Substrate; 1...Substrate handling device; 6...Camera; 10...Robot; 11...Arm; 12...Hand; 15...Robot control device.

Claims

1. A substrate handling device, wherein, have: A robot having a hand that holds a substrate and an arm that moves the hand; A robot control device that sets the movement path of the hand and controls the arm to make the hand move toward a target position along the movement path; as well as A camera configured to photograph the substrate held by the hand, which is located in a predetermined confirmation position. The robot control device sets the movement path by confirming the position, obtains an image captured by the camera when the hand is in the confirmed position, calculates the distance between the substrate captured in the image and a specified environment, and calculates the positional offset of the substrate from the reference position based on the distance. The environment is the periphery of the gate opening of the substrate processing equipment through which the substrate moving on the moving path passes.

2. The substrate handling apparatus according to claim 1, wherein, The robot control device corrects the target position based on the position offset.

3. The substrate handling apparatus according to claim 1 or 2, wherein, The hand is allowed to shift its position from the reference position in the position offset direction. The robot control device calculates the positional offset 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 a pair of gaps in the environment along the positional offset direction captured in the image.

4. The substrate handling apparatus according to claim 3, wherein, The reference position is a position where a pair of gaps at the confirmed position are of equal size.

5. A method for determining substrate position offset, wherein, The movement path is set by confirming the specified location. The image is captured by the camera when the hand, which is holding the substrate and moving along the movement path, is in the confirmed position. Calculate the distance between the substrate captured in the image and the specified environment. The positional offset of the substrate from the reference position is calculated based on the distance. The environment is the periphery of the gate opening of the substrate processing equipment through which the substrate moving on the moving path passes.

Images