Control method of substrate conveying system and substrate conveying system

Abstract

A control method for a substrate conveying system and a substrate conveying system for improving conveying accuracy are provided. A control method for a substrate conveying system, the substrate conveying system comprising: a conveying mechanism having a holding portion for holding a substrate, the conveying mechanism being used to convey the substrate; and a measuring portion for detecting the outer edge of the substrate conveyed by the conveying mechanism and measuring the center position of the substrate, the substrate conveying system conveys the substrate to a target position, wherein the target position is corrected based on an offset between a reference position of the holding portion and a center position of the substrate measured by the measuring portion, a thermal displacement amount of the reference position of the holding portion caused by thermal expansion of the conveying mechanism at a measuring position where the outer edge of the substrate is detected by the measuring portion, and a thermal displacement amount of the reference position of the holding portion caused by thermal expansion of the conveying mechanism at a target position where the substrate is conveyed, and the conveying mechanism is controlled so that the reference position of the holding portion becomes the corrected target position.

Description

Technical Field

[0001] The present disclosure relates to a control method of a substrate conveying system and a substrate conveying system. Background Art

[0002] There is known a substrate transport system including a transport mechanism for transporting a substrate such as a wafer.

[0003] Patent document 1 discloses a processing system for performing a predetermined processing on a substrate, characterized in that the processing system includes: a plurality of processing chambers for performing the predetermined processing on the substrate; a common conveying chamber having a predetermined length in one direction, and the processing chambers are commonly connected to a side portion of the common conveying chamber; a sliding mechanism having a driving source at one end thereof, and the sliding mechanism having a base that can move in the common conveying chamber along the length direction of the common conveying chamber; a substrate conveying mechanism that is mounted on the base and can bend, extend, and rotate to hold and convey the substrate and to carry the substrate in and out of the processing chamber; a plurality of position shift detection units that are arranged at predetermined intervals corresponding to positions where the base should be stopped to detect position shifts of the substrate held by the substrate conveying mechanism; and a unit control unit that controls the operation of the substrate conveying mechanism to use a detection value of any one of the plurality of position shift detection units as a reference detection value and to perform thermal expansion correction on the detection values ​​of the other position shift detection units.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2007-27378 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] However, the conveyance mechanism may suffer from heat generation of a power source of the conveyance mechanism, conveyance of a high-temperature substrate, and the like, which may cause thermal expansion of various parts of the conveyance mechanism, thereby reducing the conveyance accuracy of the substrate.

[0009] A technical solution of the present disclosure provides a control method of a substrate conveying system and a substrate conveying system for improving conveying accuracy.

[0010] Solutions for solving problems

[0011] A technical solution disclosed herein is a control method for a substrate conveying system, the substrate conveying system comprising: a conveying mechanism having a holding portion for holding a substrate, the conveying mechanism being used to convey the substrate; and a measuring portion for detecting an outer edge of the substrate conveyed by the conveying mechanism and measuring a center position of the substrate, the substrate conveying system conveys the substrate to a target position, wherein the target position is corrected based on an offset between a reference position of the holding portion and a center position of the substrate measured by the measuring portion, an amount of thermal displacement of the reference position of the holding portion caused by thermal expansion of the conveying mechanism at a measuring position where the outer edge of the substrate is detected by the measuring portion, and an amount of thermal displacement of the reference position of the holding portion caused by thermal expansion of the conveying mechanism at a target position where the substrate is conveyed, and the conveying mechanism is controlled so that the reference position of the holding portion becomes the corrected target position.

[0012] Effects of the Invention

[0013] According to a technical solution of the present disclosure, a control method of a substrate conveying system and a substrate conveying system for improving conveying accuracy are provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is an example of a plan view showing the structure of the substrate processing system 1 according to one embodiment.

[0015] Figure 2 This is an example of a perspective view of a conveying mechanism.

[0016] Figure 3 This is an example of a schematic diagram for explaining the structure of the conveying mechanism.

[0017] Figure 4 This is an example of a functional block diagram of a control device.

[0018] Figure 5 This is an example of a diagram schematically showing the posture of the conveying mechanism.

[0019] Figure 6 This is an example of a diagram for explaining the error direction of the angular transmission error.

[0020] Figure 7 This is an example of a schematic diagram for explaining correction of a target position. DETAILED DESCRIPTION

[0021] Hereinafter, the mode for implementing the present disclosure will be described with reference to the drawings. In each of the drawings, the same components are sometimes denoted by the same reference numerals, and repeated descriptions are omitted.

[0022] <Substrate processing system>

[0023] use Figure 1 An example of the overall configuration of the substrate processing system 1 according to one embodiment will be described. Figure 1 FIG. 1 is an example of a top view showing the structure of a substrate processing system 1 according to an embodiment. Figure 1 In the figure, the substrate W is illustrated with dotted hatching. In the following description, the substrate W is held by the third arm 53 of the transport mechanism 5 and is transported from the vacuum transport chamber 3 to the placement unit 41 of the processing chamber 4.

[0024] Figure 1 The substrate processing system 1 shown is a system of combined structure (multi-chamber type). The substrate processing system 1 includes a load lock chamber 2, a vacuum transfer chamber 3, a processing chamber 4, a transfer mechanism 5, a sensor 6, and a control device 7. In addition, the substrate conveying system for conveying the substrate W includes the conveying mechanism 5, the sensor 6, and the control device 7.

[0025] The load lock chamber 2 is provided between the vacuum transfer chamber 3 and the atmospheric transfer chamber (not shown). The load lock chamber 2 has a loading portion 21 for loading the substrate W. The load lock chamber 2 is configured to be switchable between atmospheric atmosphere and vacuum atmosphere. The load lock chamber 2 and the vacuum transfer chamber 3 of the vacuum atmosphere are connected by opening and closing the gate valve 22. The load lock chamber 2 and the atmospheric transfer chamber (not shown) of the atmospheric atmosphere are connected by opening and closing the gate valve (not shown). In addition, the switching to the vacuum atmosphere or the atmospheric atmosphere in the load lock chamber 2 is controlled by the control device 7.

[0026] The vacuum transfer chamber 3 is decompressed to a predetermined vacuum atmosphere. A transfer mechanism 5 for transferring the substrate W is provided inside the vacuum transfer chamber 3 .

[0027] The processing chamber 4 is arranged adjacent to the vacuum transfer chamber 3. The processing chamber 4 has a loading portion 41 for loading the substrate W. The processing chamber 4 is decompressed to a predetermined vacuum atmosphere, and a desired process (e.g., etching process, film forming process, cleaning process, ashing process, etc.) is performed on the substrate W loaded on the loading portion 41 inside the processing chamber 4. The processing chamber 4 and the vacuum transfer chamber 3 are connected by opening and closing a gate valve 42. In addition, the operation of each part of the processing chamber 4 for processing is controlled by a control device 7.

[0028] The conveying mechanism 5 carries out the transfer of the substrate W between the load lock chamber 2 and the vacuum transfer chamber 3 according to the opening and closing of the gate valve 22. In addition, the conveying mechanism 5 carries out the transfer of the substrate W between the processing chamber 4 and the vacuum transfer chamber 3 according to the opening and closing of the gate valve 42. In addition, the operation of the conveying mechanism 5 and the opening and closing of the gate valves 22 and 42 are controlled by the control device 7.

[0029] The conveying mechanism 5 is configured as a multi-joint arm including a base 50, a first arm 51, a second arm 52, a third arm 53, and a fourth arm 54, for example. One side of the first arm 51 in the longitudinal direction is connected to the base 50 in a manner that allows rotation around a rotation axis 55. The other side of the first arm 51 in the longitudinal direction is connected to one side of the second arm 52 in the longitudinal direction in a manner that allows rotation around a rotation axis 56. The other side of the second arm 52 in the longitudinal direction is connected to one side of the third arm 53 in the longitudinal direction in a manner that allows rotation around a rotation axis 57. The other side of the third arm 53 in the longitudinal direction has a holding portion 53a for holding (carrying) a substrate W. In addition, the other side of the second arm 52 in the longitudinal direction is connected to one side of the fourth arm 54 in the longitudinal direction in a manner that allows rotation around a rotation axis 57. The other side of the fourth arm 54 in the longitudinal direction has a holding portion 54a for holding (carrying) a substrate W.

[0030] Inside the vacuum transfer chamber 3, a sensor (measurement unit) 6 for detecting the substrate W transported by the transport mechanism 5 is provided corresponding to the processing chamber 4 and the load lock chamber 2. The sensor 6 is provided at a position where the substrate W passes when the transport mechanism 5 transports the substrate W from the vacuum transfer chamber 3 to the processing chamber 4 or the load lock chamber 2 or when the transport mechanism 5 transports the substrate W from the processing chamber 4 or the load lock chamber 2 to the vacuum transfer chamber 3.

[0031] The sensor 6 has two sensors 6a and 6b. The sensors 6a and 6b are, for example, photoelectric sensors. The substrate W transported by the transport mechanism 5 passes through the sensors 6a and 6b, thereby being able to detect four points of the outer edge of the substrate W. The control device 7 detects the outer edge coordinates of the substrate W held by the third arm 53 based on the detection of the outer edge of the substrate W by the sensor 6 (sensors 6a and 6b) and the operation of the transport mechanism 5 at this time. Then, the control device 7 calculates the center position of the substrate W based on the detected outer edge coordinates of the four points. Thus, the sensor 6 and the control device 7 function as a measuring unit that measures the center position of the substrate W held by the third arm 53. Thus, the control device 7 detects the offset (eccentricity) between the preset reference position of the substrate W mounted on the third arm 53 (the center position of the holding portion 53a) and the center position of the substrate W held by the third arm 53 detected by the sensor 6.

[0032] The control device 7 has a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and a HDD (Hard Disk Drive). The control device 7 is not limited to having a HDD, and may also have other storage areas such as an SSD (Solid State Drive). In the storage areas such as the HDD and RAM, a recipe for setting processing steps, processing conditions, and conveying conditions is stored.

[0033] The CPU controls the processing of the substrate W in each processing chamber according to the process and controls the conveyance of the substrate W. Alternatively, the HDD or RAM may store a program for executing the processing of the substrate W in each processing chamber and the conveyance of the substrate W. The program may be provided by being stored in a storage medium or provided from an external device via a network.

[0034] <Conveying mechanism>

[0035] Next, use Figure 2 and Figure 3 The conveying mechanism 5 will be further described. Figure 2 This is an example of a perspective view of the transport mechanism 5 . Figure 3 This is an example of a schematic diagram for explaining the structure of the conveying mechanism 5 .

[0036] The first arm 51 is provided with temperature sensors (temperature detection units) 81 and 82. As the temperature sensors 81 and 82, for example, thermocouples can be used. The temperature sensor 81 is provided on one side in the length direction of the first arm 51 (the side of the rotation axis 55). The temperature sensor 82 is provided on the other side in the length direction of the first arm 51 (the side of the rotation axis 56). The temperature of the first arm 51 detected by the temperature sensors 81 and 82 is input to the control device 7.

[0037] The second arm 52 is provided with temperature sensors (temperature detection units) 83 and 84. As the temperature sensors 83 and 84, for example, thermocouples can be used. The temperature sensor 83 is provided on one side in the length direction of the second arm 52 (the side of the rotation axis 56). The temperature sensor 84 is provided on the other side in the length direction of the second arm 52 (the side of the rotation axis 57). The temperature of the second arm 52 detected by the temperature sensors 83 and 84 is input to the control device 7.

[0038] A first shaft motor 91 is provided in the first arm 51. The first shaft motor 91 rotates a gear 92. The gear 93 is fixed to the base portion 50 and is arranged coaxially with the rotation axis 55. The gear 92 and the gear 93 constitute a meshing power transmission mechanism. Thus, the first shaft motor 91 rotates the first arm 51 around the rotation axis 55 relative to the base portion 50.

[0039] A second shaft motor 94 is provided in the first arm 51. The second shaft motor 94 rotates a gear 95. A gear 96 is fixed to the second arm 52 and is arranged coaxially with the rotation axis 56. The gear 95 and the gear 96 constitute a meshing power transmission mechanism. Thus, the second shaft motor 94 rotates the second arm 52 around the rotation axis 56 relative to the first arm 51.

[0040] A third-axis motor 97 is provided in the second arm 52. The third-axis motor 97 rotates a gear 98. The gear 99 is fixed to the third arm 53 and is arranged coaxially with the rotation axis 57. The gear 98 and the gear 99 constitute a meshing power transmission mechanism. Thus, the third-axis motor 97 rotates the third arm 53 around the rotation axis 57 relative to the second arm 52. Similarly, a motor (not shown) and a power transmission mechanism (not shown) are provided in the second arm 52, and the motor rotates the fourth arm 54 around the rotation axis 57 relative to the second arm 52.

[0041] In addition, the interaxial distance between the rotation axis 55 and the rotation axis 56 (the connecting rod length of the first arm 51) is set to L1. The interaxial distance between the rotation axis 56 and the rotation axis 57 (the connecting rod length of the second arm 52) is set to L2. The interaxial distance between the gear 92 and the gear 93 is set to Lg1. The interaxial distance between the gear 95 and the gear 96 is set to Lg2. The interaxial distance between the gear 98 and the gear 99 is set to Lg3. In addition, the material of the gears 92, 95, and 98 is Fe, and the material of the first arm 51, the second arm 52, the third arm 53, and the gears 93, 96, and 99 is Al.

[0042] Here, for the conveying mechanism 5, the first axis motor 91 and the like provided in the conveying mechanism 5 become heat sources and generate heat. In addition, heat is input from the high-temperature processing chamber 4 to the conveying mechanism 5. In addition, heat is input from the high-temperature substrate W processed in the processing chamber 4 to the conveying mechanism 5. As a result, thermal expansion occurs in the conveying mechanism 5.

[0043] like Figure 2 As shown by the black arrows, the first arm 51, the second arm 52, and the third arm 53 of the conveying mechanism 5 thermally expand in the longitudinal direction.

[0044] In addition, the backlash between the gears 92 and 93 increases due to the thermal expansion of the gears 92 and 93. Figure 2In FIG. 5 , a dashed line is used to indicate the position of the center axis of the first arm 51 in the longitudinal direction, and a dashed line is used to indicate the position of the center axis of the first arm 51 in the longitudinal direction under the influence of the backlash. Figure 2 As shown by the blank arrows, an angle transmission error occurs when the first arm 51 is rotated about the rotation axis 55 by the gears 92 and 93. Similarly, the backlash of the gears 95 and 96 and the gears 98 and 99 increases, and an angle transmission error occurs.

[0045] Next, use Figure 4 The control device 7 that controls the conveying mechanism 5 will be described. Figure 4 This is an example of a functional block diagram of the control device 7.

[0046] The first-axis angle sensor 91a detects the rotation angle of the first-axis motor 91. The detection value of the first-axis angle sensor 91a is input to the control device 7. The second-axis angle sensor 94a detects the rotation angle of the second-axis motor 94. The detection value of the second-axis angle sensor 94a is input to the control device 7. The third-axis angle sensor 97a detects the rotation angle of the third-axis motor 97. The detection value of the third-axis angle sensor 97a is input to the control device 7.

[0047] In addition, the detection values ​​of the temperature sensors 81 to 84 are input to the control device 7. The detection value of the sensor 6 is input to the control device 7.

[0048] In addition, the control device 7 controls the first axis motor 91, the second axis motor 94, and the third axis motor 97. The control device 7 controls the first axis motor 91, the second axis motor 94, and the third axis motor 97 based on the detection values ​​of the first axis angle sensor 91a, the second axis angle sensor 93a, and the third axis angle sensor 97a, thereby controlling the operation of the conveying mechanism 5.

[0049] Furthermore, the control device 7 includes a thermal expansion amount estimation unit 71 , an angle transmission error estimation unit 72 , an angle error direction estimation unit 73 , and a target position correction unit 74 .

[0050] The thermal expansion amount estimation unit 71 estimates the thermal expansion amounts of the first arm 51 and the second arm 52 .

[0051] The amount of thermal expansion of the first arm 51 is estimated based on, for example, the temperature of the first arm 51, the thermal expansion coefficient of the first arm 51, and the reference connecting rod length L1 of the first arm 51. In addition, the temperature of the first arm 51 is detected by the temperature sensors 81 and 82. For example, the average value of the temperature sensors 81 and 82 may be used as the temperature of the first arm 51. In addition, when the first arm 51 is formed of Al, the thermal expansion coefficient of the first arm 51 may be set to the thermal expansion coefficient of Al. The reference connecting rod length L1 of the first arm 51 is the connecting rod length of the first arm 51 at the reference temperature.

[0052] The amount of thermal expansion of the second arm 52 is estimated based on, for example, the temperature of the second arm 52, the thermal expansion coefficient of the second arm 52, and the reference connecting rod length L2 of the second arm 52. In addition, the temperature of the second arm 52 is detected by the temperature sensors 83 and 84. For example, the average value of the temperature sensors 83 and 84 may be used as the temperature of the second arm 52. In addition, when the second arm 52 is formed of Al, the thermal expansion coefficient of the second arm 52 may be set to the thermal expansion coefficient of Al. The reference connecting rod length L2 of the second arm 52 is the connecting rod length of the second arm 52 at the reference temperature.

[0053] The angle transmission error estimation unit 72 estimates the amount of angle transmission error caused by the backlash of the gears.

[0054] The amount of angular transmission error when the first arm 51 is rotated around the rotation axis 55 is estimated based on, for example, the temperature of the gears 92 and 93, the difference in thermal expansion coefficients of the gears 92 and 93, and the reference axis distance Lg1 of the gears 92 and 93. In addition, the temperature of the gears 92 and 93 is detected by, for example, the temperature sensor 81. In addition, when the gear 92 is formed of Fe and the gear 93 is formed of Al, the difference in thermal expansion coefficients of the gears 92 and 93 may be set to the difference between the thermal expansion coefficients of Fe and the thermal expansion coefficients of Al. The reference axis distance Lg1 is the axis distance of the gears 92 and 93 at the reference temperature.

[0055] The amount of angular transmission error when the second arm 52 is rotated around the rotation axis 56 is estimated based on, for example, the temperature of the gears 95 and 96, the difference in thermal expansion coefficients of the gears 95 and 96, and the reference axis distance Lg2 of the gears 95 and 96. In addition, the temperature of the gears 95 and 96 is detected by, for example, the temperature sensor 82. In addition, when the gear 95 is formed of Fe and the gear 96 is formed of Al, the difference in thermal expansion coefficients of the gears 95 and 96 may be set to the difference between the thermal expansion coefficients of Fe and the thermal expansion coefficients of Al. The reference axis distance Lg2 is the axis distance of the gears 95 and 96 at the reference temperature.

[0056] The amount of angular transmission error when the third arm 53 is rotated around the rotation axis 57 is estimated based on, for example, the temperature of the gears 98 and 99, the difference in thermal expansion coefficients of the gears 98 and 99, and the reference axis distance Lg3 of the gears 98 and 99. In addition, the temperature of the gears 98 and 99 is detected by, for example, the temperature sensor 84. In addition, in the case where the gear 98 is formed of Fe and the gear 99 is formed of Al, the difference in thermal expansion coefficients of the gears 98 and 99 may be set to the difference between the thermal expansion coefficients of Fe and the thermal expansion coefficients of Al. The reference axis distance Lg3 is the axis distance of the gears 98 and 99 at the reference temperature. In addition, the amount of angular transmission error when the fourth arm 54 is rotated around the rotation axis 57 is similarly estimated.

[0057] The angle error direction estimation unit 73 estimates the direction of the angle transmission error.

[0058] Figure 5 This is an example of a diagram schematically showing the posture of the conveying mechanism 5 . Figure 5 (a) is a diagram showing an example of the posture of the transport mechanism 5 at a measurement position where the substrate W is measured by the sensor 6 . Figure 5 (b) is a diagram showing an example of the posture of the transport mechanism 5 at the target position of the substrate W being transported.

[0059] As indicated by the dotted arrows, the link lengths of the first arm 51 and the second arm 52 thermally expand. In addition, since the reference position of the third arm 53 for mounting the substrate W is set at a predetermined distance from the rotation axis 57, the thermal expansion of the third arm 53 may not be considered.

[0060] In addition, Figure 5 In the measurement position shown in (a) of FIG. 1 , the conveying mechanism 5 causes the substrate W to pass over the sensor 6 while accelerating the substrate W. Therefore, the conveyed substrate W is subjected to an inertial force in the direction indicated by the blank arrow. Figure 5 In the target position shown in (b), the transport mechanism 5 moves the substrate W toward the target position of the placement unit 41 while decelerating the substrate W, and then stops. Therefore, the transported substrate W is subjected to an inertial force in the direction shown by the white arrow.

[0061] Here, use Figure 6 The relationship between the acceleration / deceleration state and the error direction of the angle transmission error is explained. Figure 6 This is an example of a diagram for explaining the error direction of the angular transmission error. Figure 6 (a) shows the acceleration of the first-axis motor 91 . Figure 6 (b) shows the deceleration of the first shaft motor 91. In addition, the solid arrows show the rotation direction of each gear.

[0062] exist Figure 6When the first axis motor 91 shown in (a) is accelerated, the gear 92 on the first stage side rotates clockwise, and the gear 93 on the second stage side rotates counterclockwise. At this time, due to the inertial force, the teeth of the gear 92 on the first stage side contact the teeth of the gear 93 on the second stage side in the direction of pressing the teeth of the gear 93 on the second stage side. As a result, an angular transmission error caused by the backlash occurs in the direction indicated by the blank arrow.

[0063] On the other hand, Figure 6 When the first axis motor 91 shown in (b) is decelerated, the gear 92 on the first stage side rotates clockwise, and the gear 93 on the second stage side rotates counterclockwise. At this time, due to the inertial force, the teeth of the gear 93 on the second stage side contact the teeth of the gear 92 on the first stage side in the direction of pressing the teeth of the gear 92 on the first stage side. As a result, an angular transmission error caused by the backlash occurs in the direction indicated by the blank arrow.

[0064] Thus, the direction of the angular transmission error caused by the backlash between gears 92 and 93 is different when the first axis motor 91 is accelerated or decelerated. The direction of the angular transmission error caused by the backlash between gears 95 and 96 and gears 98 and 99 is also the same. Figure 5 In FIG. 1 , a solid arrow is used to show an example of the direction of the angle transmission error. Figure 5 The measurement position shown in (a) Figure 5 In the target position shown in (b), the direction of the angle transfer error changes.

[0065] The angle error direction estimation unit 73 estimates the direction of the angle transmission error when the first arm 51 is rotated around the rotation axis 55 based on the acceleration and deceleration state of the first axis motor 91. Similarly, the angle error direction estimation unit 73 estimates the direction of the angle transmission error when the second arm 52 is rotated around the rotation axis 56 based on the acceleration and deceleration state of the second axis motor 94. The angle error direction estimation unit 73 estimates the direction of the angle transmission error when the third arm 53 is rotated around the rotation axis 57 based on the acceleration and deceleration state of the third axis motor 97. In addition, the direction of the angle transmission error when the fourth arm 54 is rotated around the rotation axis 57 is also estimated in the same manner.

[0066] The target position correction unit 74 corrects the target position based on the offset between the reference position of the third arm 53 and the center position of the substrate W held by the third arm 53, the position offset of the reference position of the third arm 53 caused by thermal expansion at the measurement position, and the position offset of the reference position of the third arm 53 caused by thermal expansion at the target position.

[0067] The deviation between the reference position of the third arm 53 and the center position of the substrate W held by the third arm 53 is estimated based on the detection value of the sensor 6 .

[0068] The positional deviation (thermal displacement) of the reference position of the third arm 53 due to thermal expansion at the measurement position is based on the thermal expansion amounts of the first arm 51 and the second arm 52 estimated by the thermal expansion amount estimation unit 71, the angle transmission error amount estimated by the angle transmission error estimation unit 72, and the measurement position estimated by the angle error direction estimation unit 73 (refer to Figure 5 It is calculated based on the direction of the angular transmission error at (a)) and the posture of the conveying mechanism 5 (the detection values ​​of the angle sensors 91a, 94a, and 97a).

[0069] The positional deviation (thermal displacement) of the reference position of the third arm 53 caused by thermal expansion at the target position is based on the thermal expansion amounts of the first arm 51 and the second arm 52 estimated by the thermal expansion amount estimation unit 71, the angle transmission error amount estimated by the angle transmission error estimation unit 72, and the target position estimated by the angle error direction estimation unit 73 (refer to Figure 5 It is calculated based on the direction of the angular transmission error at (b)) and the posture of the conveying mechanism 5 (the detection values ​​of the angle sensors 91a, 94a, and 97a).

[0070] In addition, when the temperature change of the conveying mechanism 5 during the conveying process of the substrate W is very small, the thermal expansion amount of the first arm 51 and the second arm 52 at the measurement position and the target position and the angular transmission error amount at the rotation axis 55, 56, 57 can also be regarded as unchanged. On the other hand, the direction of the angular transmission error is different between the measurement position where the substrate W is conveyed in an accelerated state and the target position where the substrate W is conveyed in a decelerated state. In addition, the posture of the conveying mechanism 5 is different between the measurement position and the target position. Therefore, the positional offset of the reference position at the measurement position and the positional offset of the reference position at the target position are different.

[0071] Here, use Figure 7 The correction of the target position is further described. Figure 7 1 is an example of a schematic diagram for explaining the correction of the target position. Position 100 shows the target position. Position 101 is the reference position of the third arm 53 when the reference position of the third arm 53 (the center position of the holding portion 53a) is controlled to move to the target position without correction. Arrow 111 shows the offset (thermal displacement) of the reference position of the third arm 53 at the target position caused by thermal expansion. Figure 5 As shown in (b), due to the thermal expansion of the conveying mechanism 5, a deviation of the reference position occurs at the target position.

[0072] Position 102 is the reference position of the third arm 53 when the target position is corrected using the sensor 6 based on the deviation between the reference position of the third arm 53 (the center position of the holding portion 53a) and the center position of the substrate W held by the third arm 53, and when control is performed to move the reference position of the third arm 53 to the corrected target position. Arrow 110 shows the deviation amount of the reference position. Figure 5 As shown in (a), due to the thermal expansion of the conveying mechanism 5, an offset of the reference position is generated at the measurement position. Therefore, the offset between the reference position of the third arm 53 and the center position of the substrate W held by the third arm 53 includes the offset of the reference position at the measurement position. Therefore, when the sensor 6 is used to correct the target position based on the offset between the reference position of the third arm 53 and the center position of the substrate W held by the third arm 53, the offset of the reference position at the measurement position indicated by the arrow 111 is corrected. That is, an offset (arrow 110) is generated by superimposing the inverse of the offset (thermal displacement) of the reference position of the third arm 53 caused by thermal expansion at the measurement position indicated by the arrow 112 and the offset (thermal displacement) of the reference position of the third arm 53 caused by thermal expansion at the target position indicated by the arrow 111.

[0073] Here, when the offset between the reference position of the third arm 53 detected by the sensor 6 and the center position of the substrate W held by the third arm 53 is set to (X0, Y0), the offset of the reference position at the measurement position is set to (X1, Y1), and the offset of the reference position at the target position is set to (X2, Y2), the correction amount of the target position is expressed as (-X0-X2+X1, -Y0-Y2+Y1).

[0074] In other words, the true offset (X0-X1, Y0-Y1) between the reference position and the center position of the substrate W held by the third arm 53 can be obtained based on the offset (X0, Y0) between the reference position of the third arm 53 detected by the sensor 6 and the center position of the substrate W held by the third arm 53, and the offset (X1, Y1) of the reference position at the measurement position. Therefore, the correction amount (-X0-X2+X1, -Y0-Y2+Y1) of the target position can be obtained based on the offset (X2, Y2) of the reference position at the target position and the true offset (X0-X1, Y0-Y1) between the reference position and the center position of the substrate W.

[0075] Then, the control device 7 controls the conveying mechanism 5 so that the reference position of the third arm 53 becomes the corrected target position. For example, the control device 7 calculates the target angle of the rotation axis 55, the target angle of the rotation axis 56, and the target angle of the rotation axis 57 based on the corrected target position. Then, the control device 7 controls the motors 91, 94, 97 so that the detection values ​​of the angle sensors 91a, 94a, 97a become the target angles.

[0076] As described above, according to the substrate conveying system of this embodiment, the target position can be corrected in consideration of the thermal displacement of the conveying mechanism 5, thereby improving the conveying accuracy when conveying the substrate W to the target position. The deviation between the center position of the substrate W conveyed by the conveying mechanism 5 and the target position can be reduced. In addition, although the case where the substrate W is conveyed by the third arm 53 is described as an example, the conveying accuracy can also be improved by the same control when the substrate W is conveyed by the fourth arm 54.

[0077] Although the embodiments of the substrate processing system 1 and the substrate transfer system have been described above, the present disclosure is not limited to the above embodiments, and various modifications and improvements can be made within the scope of the gist of the present disclosure described in the claims.

[0078] Although the case where the conveying mechanism 5 is provided with a temperature sensor for each arm has been described, the present invention is not limited thereto. For an arm not provided with a temperature sensor, the temperature of the arm may be estimated based on the temperatures of the preceding and following arms and past data.

Claims

1. A control method for a substrate conveying system, the substrate conveying system comprising: A conveying mechanism having a holding portion for holding a substrate, the conveying mechanism being used to convey the substrate; as well as a measuring unit that detects the outer edge of the substrate conveyed by the conveying mechanism and measures the center position of the substrate, The substrate conveying system conveys the substrate to a target position, wherein: The target position is corrected based on an amount of deviation between a reference position of the holding portion and a center position of the substrate measured by the measuring portion, an amount of thermal displacement of the reference position of the holding portion caused by thermal expansion of the conveying mechanism at a measurement position where the outer edge of the substrate is detected by the measuring portion, and an amount of thermal displacement of the reference position of the holding portion caused by thermal expansion of the conveying mechanism at a target position where the substrate is conveyed, controlling the conveying mechanism so that the reference position of the holding portion becomes the corrected target position, Wherein, the conveying mechanism further comprises: an arm connected in a rotatable manner; and A driving source that rotates the arm by means of a power transmission mechanism including a plurality of gears, wherein the thermal displacement amount of the reference position of the holding portion at the measurement position and the thermal displacement amount of the reference position of the holding portion at the target position are estimated based on the thermal expansion amount of the arm estimated based on the temperature of the arm, the angular transmission error amount of the power transmission mechanism estimated based on the temperature of the power transmission mechanism, and the direction of the angular transmission error estimated based on the acceleration / deceleration state of the driving source, and the angular transmission error amount is estimated based on a reference inter-axial distance that is the inter-axial distance of the gears at a reference temperature.

2. The control method of the substrate conveying system according to claim 1, wherein: The angular transmission error amount is based on the backlash of the gears.

3. The control method of the substrate conveying system according to claim 1 or 2, wherein: The transport mechanism includes a temperature detection unit for detecting a temperature of the transport mechanism.

4. A substrate conveying system, wherein: The substrate conveying system includes: A conveying mechanism having a holding portion for holding a substrate, the conveying mechanism being used to convey the substrate; a measuring unit that detects an outer edge of the substrate conveyed by the conveying mechanism and measures a center position of the substrate; and a control unit, which controls the conveying mechanism, the control unit corrects the target position based on an amount of deviation between a reference position of the holding unit and a center position of the substrate measured by the measuring unit, an amount of thermal displacement of the reference position of the holding unit caused by thermal expansion of the conveying mechanism at a measurement position where the outer edge of the substrate is detected by the measuring unit, and an amount of thermal displacement of the reference position of the holding unit caused by thermal expansion of the conveying mechanism at a target position where the substrate is conveyed, The control unit controls the conveying mechanism so that the reference position of the holding unit becomes the corrected target position. Wherein, the conveying mechanism further comprises: an arm connected in a rotatable manner; and A driving source that rotates the arm by means of a power transmission mechanism including a plurality of gears, wherein the thermal displacement amount of the reference position of the holding portion at the measurement position and the thermal displacement amount of the reference position of the holding portion at the target position are estimated based on the thermal expansion amount of the arm estimated based on the temperature of the arm, the angular transmission error amount of the power transmission mechanism estimated based on the temperature of the power transmission mechanism, and the direction of the angular transmission error estimated based on the acceleration / deceleration state of the driving source, and the angular transmission error amount is estimated based on a reference inter-axial distance that is the inter-axial distance of the gears at a reference temperature.

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