Conveying device, processing system and conveying method

Abstract

A conveying device according to one embodiment of the present invention comprises: a first holding portion for holding the substrate by contacting an end portion of the substrate; and a second holding portion formed by an elastic component for holding the substrate by contacting only the back side of the substrate.

Description

Technical Field

[0001] The invention relates to a conveying device, a processing system and a conveying method. Background Art

[0002] A pickup having an edge clamping function for holding a wafer at an end portion is known (for example, refer to Patent Document 1).

[0003] <Prior Art Literature>

[0004] <Patent Documents>

[0005] Patent Document 1: Japanese Patent Application Publication No. 2012-74498 Summary of the invention

[0006] <Problems to be Solved by the Invention>

[0007] The present invention provides a technology capable of changing the holding position of a substrate according to the type of the substrate.

[0008] <Methods used to solve the problem>

[0009] A conveying device according to one embodiment of the present invention comprises: a first holding portion for holding the substrate by contacting an end portion of the substrate; and a second holding portion formed by an elastic component for holding the substrate by contacting only the back side of the substrate.

[0010] <Effects of the Invention>

[0011] According to the present invention, the holding position of the substrate can be changed according to the type of the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a diagram showing an example of a processing system according to an embodiment.

[0013] Figure 2 This is a diagram showing an example of the hardware configuration of the control device.

[0014] Figure 3 It is a top view showing an example of a conveying device.

[0015] Figure 4 This is a cross-sectional view (1) showing an example of a conveying device.

[0016] Figure 5 This is a cross-sectional view (2) showing an example of a conveying device.

[0017] Figure 6 This is a cross-sectional view (3) showing an example of a conveying device.

[0018] Figure 7This is a flowchart showing an example of a transportation method according to an embodiment.

[0019] Figure 8 It is a diagram showing an example of a pre-processing conveyance pattern. DETAILED DESCRIPTION

[0020] Hereinafter, non-limiting exemplary embodiments of the present invention will be described with reference to the accompanying drawings. In all the drawings, the same or corresponding components or parts are given the same or corresponding reference numerals, and repeated descriptions are omitted.

[0021] 〔Processing system〕

[0022] Reference Figure 1 , a processing system of an implementation method is described. Figure 1 This is a diagram showing an example of a processing system according to an embodiment.

[0023] The processing system 1 includes a transfer module 10 , four process modules 20 , a loading module 30 , two load lock modules 40 , and a control device 100 .

[0024] The transfer module 10 has a roughly hexagonal shape in a top view. The transfer module 10 is composed of a vacuum chamber and has a conveying device 11 arranged inside. The conveying device 11 is formed by a multi-jointed arm, which can be extended, lifted, and rotated to a position that can reach the process module 20 and the loading and locking module 40. The conveying device 11 has two pickers 12 that can independently extend and retract in opposite directions, so that two wafers W can be conveyed at a time. It should be noted that the conveying device 11 is not limited to any other device as long as it can convey the wafer W between the process module 20 and the loading and locking module 40. Figure 1 The composition shown.

[0025] The process modules 20 are radially arranged around the transfer module 10 and connected to the transfer module 10. The process module 20 is composed of a processing chamber, and has a cylindrical workbench 21 inside for mounting the wafer W. In the process module 20, a predetermined process such as a film forming process is performed on the wafer W mounted on the workbench 21. The transfer module 10 and the process module 20 are separated by a gate valve 22 that can be opened and closed.

[0026] The loading module 30 is arranged opposite to the transfer module 10. The loading module 30 is a rectangular parallelepiped, and is an atmospheric conveying chamber maintained at an atmospheric pressure atmosphere. A conveying device 31 is arranged in the loading module 30. The conveying device 31 is supported so as to be able to slide on a guide rail 32 provided in a manner extending in the central part of the loading module 30 in the longitudinal direction. A linear motor having an encoder, for example, is built into the guide rail 32, and the conveying device 31 moves along the guide rail 32 by driving the linear motor.

[0027] The conveying device 31 has two multi-joint arms 33 configured in upper and lower stages as conveying arms. A picker 34 formed in a forked shape is installed at the top end of each multi-joint arm 33. Wafer W is held on each picker 34. Each multi-joint arm 33 can be extended and retracted from the center in the radial direction and raised and lowered. In addition, the extension and retraction action of each multi-joint arm 33 can be controlled individually. Each rotation axis of the multi-joint arm 33 is connected in a manner that can rotate coaxially relative to the base 35, for example, it can rotate integrally in the rotation direction relative to the base 35. The guide rail 32 and the multi-joint arm 33 act as a driving mechanism for moving the picker 34. The conveying device 31 is used to convey wafers W between the loading and locking module 40, the conveying container 51, and the aligner 60 described later. It should be noted that the conveying device 31 is not limited to any other device as long as it can convey wafers W between the loading and locking module 40, the conveying container 51, and the aligner 60. Figure 1 The composition shown.

[0028] Two loading lock modules 40 are connected to one side along the length direction of the loading module 30. On the other hand, one or more carrying ports 36 for introducing wafers W are provided on the other side along the length direction of the loading module 30. In the example shown in the figure, three carrying ports 36 are provided. At each carrying port 36, an opening and closing door 37 that can be opened and closed is provided. In addition, a loading port 50 is provided corresponding to each carrying port 36. A conveying container 51 for accommodating and conveying wafers W is placed in the loading port 50. The conveying container 51 can be a FOUP (Front-Opening Unified Pod), which accommodates multiple wafers W (for example, 25 wafers) by placing them in multiple stages with a predetermined interval.

[0029] An aligner 60 is connected to one side surface along the width direction of the loading module 30. The aligner 60 positions the wafer W. The aligner 60 has a rotating table 62 that rotates under the action of a driving motor (not shown), and rotates in a state where the wafer W is placed on the rotating table 62. The rotating table 62 has a diameter smaller than the diameter of the wafer W. An optical sensor 63 for detecting the peripheral edge of the wafer W is provided on the outer periphery of the rotating table 62. The aligner 60 detects the center position of the wafer W and the direction of the notch relative to the center of the wafer W through the optical sensor 63, and adjusts the position of the transported wafer W in such a way that the center position of the wafer W and the direction of the notch in the loading lock module 40 become a predetermined position and direction.

[0030] The load lock module 40 is arranged between the transfer module 10 and the loading module 30. The load lock module 40 is composed of a variable internal pressure chamber that can switch between vacuum and atmospheric pressure. A cylindrical workbench 41 for placing the wafer W is provided inside the load lock module 40. The workbench 41 has a diameter smaller than the diameter of the wafer W. When the load lock module 40 carries the wafer W from the loading module 30 to the transfer module 10, the internal pressure is maintained at atmospheric pressure, and the wafer W is received from the loading module 30, and then the internal pressure is reduced to carry the wafer W into the transfer module 10. In addition, when the wafer W is carried out from the transfer module 10 to the loading module 30, the internal pressure is increased to atmospheric pressure, and the wafer W is carried into the loading module 30 after the internal pressure is increased to atmospheric pressure. The load lock module 40 and the transfer module 10 are separated by an openable and closable gate valve 42. In addition, the load lock module 40 and the loading module 30 are separated by an openable and closable gate valve 43.

[0031] The control device 100 controls the operation of each component of the processing system 1. Figure 2 As shown, the control device 100 is a computer having a drive device 101, an auxiliary storage device 102, a memory device 103, a CPU 104, an interface device 105, a display device 106, etc., which are connected to each other via a bus 108. The program for realizing the processing in the control device 100 is provided by a storage medium 107 such as a CD-ROM. If the storage medium 107 storing the program is placed in the drive device 101, the program is installed from the storage medium 107 to the auxiliary storage device 102 through the drive device 101. However, the installation of the program does not necessarily have to be performed through the storage medium 107, and it can be downloaded from other computers through the network. The auxiliary storage device 102 is used to store necessary information such as the installed program and scheme. The memory device 103 reads and stores the program from the auxiliary storage device 102 when there is a program startup instruction. The CPU 104 executes the function of the processing system 1 according to the program stored in the memory device 103. The interface device 105 is used as an interface for connecting to the network. The display device 106 displays various information and functions as an operation unit for receiving the operation of the operator.

[0032] 〔Conveying device〕

[0033] Reference Figure 3 to Figure 6 , an example of the conveying device 31 in the above-mentioned processing system 1 is described. It should be noted that the conveying device 11 can be the same as the conveying device 31. Figure 3 It is a plan view showing an example of the conveying device 31 . Figures 4 to 6 is a cross-sectional view showing an example of the conveying device 31, which shows Figure 3 The cross section cut at the dotted line AB.

[0034] The conveying device 31 includes a multi-joint arm 410, a picker 420, a restricting body 430, a pressing and holding portion 440, and an elastic body 450. The multi-joint arm 410 and the picker 420 are respectively equivalent to Figure 1 The multi-jointed arm 33 and the picker 34 are provided.

[0035] The pickup 420 is formed in a plate shape and has a substantially U-shape in a plan view. In the pickup 420 , a base end portion 421 is connected to the top end of the multi-joint arm 410 .

[0036] The limiting body 430 is provided at the tip portion 422 of the pickup 420. The limiting body 430 is provided, for example, at a position not close to the wafer W held by the elastic body 450 (see Figure 6 ) contact position. The limiting body 430 has a limiting wall 431 that limits the wafer W on the pickup 420 so that it does not move in the horizontal direction. The limiting wall 431 is provided at a position higher than the position where the elastic body 450 holds the wafer W, and holds the wafer W at this position. The limiting wall 431, for example, includes a vertical portion 431a and a tapered portion 431b inclined below the vertical portion 431a. However, the limiting wall 431 may include a vertical portion 431a and a horizontal portion extending horizontally below the vertical portion 431a. Since the limiting body 430 contacts the end of the wafer W, it is preferably made of a material that does not damage the wafer W, such as a resin.

[0037] The pressing and holding portion 440 is provided at a position separated from the limiting body 430, for example, provided at the base end portion 421 of the pickup 420 and not in contact with the wafer W held by the elastic body 450 (see Figure 6 However, the pressing and holding part 440 may also be provided on the multi-joint arm 410. The pressing and holding part 440 includes a pressing body 441 and a driving part 442.

[0038] The pressing body 441 is in free contact with the end of the wafer W, and abuts against and presses the end of the wafer W. The pressing body 441 is provided at a position higher than the position where the elastic body 450 holds the wafer W, and holds the wafer W at this position. Since the pressing body 441 is in contact with the end of the wafer W, it is preferably made of a material that does not damage the wafer W, such as a resin.

[0039] The driving unit 442 drives the pressing body 441 to move the pressing body 441 to a plurality of positions. The plurality of positions include a receiving position, a holding position, and a retreat position. Figure 4 As shown, the receiving position is the position where the wafer W is received by the limiting body 430 and the pressing body 441, and is a position between the holding position and the retreat position. Figure 5As shown, the holding position is the position where the pressing body 441 is stretched, and is the position where the wafer W is held between the limiting body 430 and the pressing body 441 by pressing the end of the wafer W against the limiting wall 431 of the limiting body 430. Figure 6 As shown, the retreat position is a position where the pressing body 441 is retracted, and is a position where the pressing body 441 does not contact the wafer W when only the back side of the wafer W is held by the elastic body 450. The driving unit 442 is composed of, for example, an electric cylinder. However, the driving unit 442 may also be composed of, for example, a linear motor, a stepping motor, a DC motor, or a cylinder.

[0040] The elastic body 450 is provided on the upper surface of the pickup 420 and is provided at a position that does not contact the wafer W held by the limiting body 430 and the pressing body 441. The elastic body 450 does not contact the side surface of the wafer W, but only contacts the back surface of the wafer W to hold the wafer W. In addition, the horizontal position and vertical position of the wafer W held by the elastic body 450 (refer to Figure 6 ) and the horizontal position and vertical position of the wafer W held by the limiting body 430 and the pressing body 441 (refer to Figure 5 ) is different. A plurality of (eg, four) elastic bodies 450 are provided at, for example, the tip portion 422 of the pickup 420. The elastic body 450 is formed of an elastic member such as an O-ring.

[0041] In the conveying device 31, as Figure 4 As shown in FIG. 1 , the pressing body 441 is moved to the receiving position and the wafer W is received by the limiting body 430 and the pressing body 441. Figure 5 As shown, the pressing body 441 is moved to the holding position. As a result, the end of the wafer W is pressed against the limiting wall 431 of the limiting body 430, and the wafer W is held between the limiting body 430 and the pressing body 441. In other words, the limiting body 430 and the pressing body 441 function as a first holding portion that contacts the end of the wafer W and holds the wafer W.

[0042] In addition, Figure 6 As shown, after the pressing body 441 is moved to the retreat position, the wafer W is received by the elastic body 450, so that the wafer W is held in a state where only the back surface of the wafer W contacts the elastic body 450. In other words, the elastic body 450 functions as a second holding portion that contacts only the back surface of the wafer W and holds the wafer W.

[0043] As described above, the conveying device 31 of the embodiment includes a first holding portion (the limiting body 430 and the pressing body 441) that contacts the end of the wafer W to hold the wafer W, and a second holding portion (the elastic body 450) that contacts only the back surface of the wafer W to hold the wafer W. Thus, the holding position of the wafer W can be changed according to the type of the wafer W.

[0044] 〔Transportation method〕

[0045] Reference Figure 7 An example of the operation of the conveying device 31 conveying the wafer W in the processing system 1 (hereinafter referred to as “conveying method”) will be described. Figure 7 2 is a flowchart showing an example of the transport method according to the embodiment. The following transport method is executed by the control device 100 when the transport container 51 is placed on the load port 50 , for example.

[0046] In step S1, the control device 100 obtains a conveying mode (hereinafter referred to as "pre-processing conveying mode") for a wafer W before processing in the process module 20 (hereinafter referred to as "pre-processing wafer"). For example, the control device 100 obtains a pre-processing conveying mode corresponding to the type of pre-processing wafer contained in the conveying container 51 mounted on the load port 50. As the type of pre-processing wafer, pseudo wafers, product wafers, and bonded wafers can be cited. The pre-processing conveying mode includes information on whether the wafer W can be held at the end (hereinafter referred to as "holding position information") and information on whether the wafer W can be conveyed at a high speed (hereinafter referred to as "conveying speed information"). The correspondence between the pre-processing wafer and the pre-processing conveying mode is stored in the auxiliary storage device 102, for example.

[0047] Figure 8 FIG. 1 is a diagram showing an example of a conveying pattern before processing. Figure 8 As shown, the pre-processing conveying mode has, for example, four conveying modes A to D. Conveying mode A includes information indicating that the wafer W can be held at the end as holding position information and information indicating that it can be conveyed at high speed as conveying speed information. Conveying mode B includes information indicating that the wafer W can be held at the end as holding position information and information indicating that it cannot be conveyed at high speed as conveying speed information. Conveying mode C includes information indicating that the wafer W cannot be held at the end as holding position information and information indicating that it can be conveyed at high speed as conveying speed information. Conveying mode D includes information indicating that the wafer W cannot be held at the end as holding position information and information indicating that it cannot be conveyed at high speed as conveying speed information.

[0048] In addition, for example, the control device 100 may display a screen for the operator to select the pre-processing conveying mode on the display device 106 after the conveying container 51 is placed on the loading port 50. In this case, the control device 100 obtains the pre-processing conveying mode selected by the operator by operating the display device 106. In this way, the selection of the pre-processing conveying mode may be performed automatically or manually.

[0049] In step S2, the control device 100 determines whether the pre-processed wafer contained in the transport container 51 can be held at the end based on the holding position information included in the pre-processing transport pattern obtained in step S1. If it is determined in step S2 that the pre-processed wafer can be held at the end, the control device 100 advances the process to step S3. On the other hand, if it is determined in step S2 that the pre-processed wafer cannot be held at the end, the control device 100 advances the process to step S5.

[0050] In step S3, the control device 100 determines whether the pre-processed wafers contained in the transport container 51 can be transported at high speed based on the transport speed information included in the pre-processing transport mode obtained in step S1. If it is determined in step S3 that the pre-processed wafers can be transported at high speed, the control device 100 advances the process to step S4. On the other hand, if it is determined in step S3 that the pre-processed wafers cannot be transported at high speed, the control device 100 advances the process to step S5.

[0051] In step S4, the control device 100 sets the action of the conveying device 31 for the pre-processed wafer so as to make the limiting body 430 and the pressing body 441 contact the end of the wafer W to hold the wafer W (hereinafter referred to as "end holding conveying"). The action of the conveying device 31 includes information related to the training position, for example.

[0052] In step S5, the control device 100 sets the action of the conveying device 31 for the pre-processed wafer so that the elastic body 450 is in contact with only the back side of the wafer W to hold the wafer W (hereinafter referred to as "back side holding conveying"). The action of the conveying device 31 includes information related to the training position, for example.

[0053] In step S6, the control device 100 obtains a transport mode (hereinafter referred to as a "post-processing transport mode") for the wafer W that has been processed in the process module 20 (hereinafter referred to as a "processed wafer"). For example, the control device 100 obtains a post-processing transport mode corresponding to the type of unprocessed wafers contained in the transport container 51 mounted on the load port 50. The post-processing transport mode is the same as the pre-processing transport mode, including the holding position information and the transport speed information. The selection of the post-processing transport mode is the same as the selection of the pre-processing transport mode, and can be performed automatically or manually.

[0054] In step S7, the control device 100 determines whether the unprocessed wafer contained in the transport container 51 can be held at the end after being processed by the process module 20 based on the holding position information included in the post-processing transport mode obtained in step S6. If it is determined in step S7 that the processed wafer can be held at the end, the control device 100 advances the process to step S8. On the other hand, if it is determined in step S7 that the processed wafer cannot be held at the end, the control device 100 advances the process to step S10.

[0055] In step S8, the control device 100 determines whether the unprocessed wafers contained in the transport container 51 can be transported at high speed after being processed by the process module 20 based on the transport speed information included in the post-processing transport mode obtained in step S6. If it is determined in step S8 that the processed wafers can be transported at high speed, the control device 100 causes the process to proceed to step S9. On the other hand, if it is determined in step S8 that the processed wafers cannot be transported at high speed, the control device 100 causes the process to proceed to step S10.

[0056] In step S9, the control device 100 sets the operation of the transport device 31 for the processed wafer so as to perform end-hold transport, and ends the process. The operation of the transport device 31 includes information related to the training position, for example.

[0057] In step S10, the control device 100 sets the operation of the transport device 31 for the processed wafer so as to perform backside holding transport, and ends the process. The operation of the transport device 31 includes information related to the training position, for example.

[0058] Through the above-described conveying method, the wafer W can be conveyed with its end portion held or with its backside held, depending on the type of the wafer W, using one conveying device 31 .

[0059] For example, the control device 100 controls the conveying device 31 so that when holding a pseudo wafer, the first holding portion is in contact with the end of the wafer W to hold it, and when holding a product wafer, the second holding portion is in contact with only the back surface of the wafer W to hold it. Thus, the operation of holding the end of the wafer W and conveying the pseudo wafer at a high speed, and the operation of conveying the product wafer while keeping the end of the wafer W clean, can be performed by one conveying device 31.

[0060] In addition, for example, the control device 100 controls the conveying device 31 so that when holding a pre-processed wafer, the wafer W is held by one of the first holding unit and the second holding unit, and when holding a processed wafer, the wafer W is held by the other holding unit. Thus, cross contamination can be prevented.

[0061] In addition, for example, the control device 100 controls the conveying device 31 so that when holding a wafer after bonding a plurality of wafers (hereinafter referred to as a "bonded wafer"), the second holding portion is in contact with only the back side of the wafer W for holding. In bonded wafers, there is a case where one wafer is ground to be thinner after the wafers are bonded. In this case, if a strong impact is applied to the end of the wafer, there is a concern that the wafer will peel off from the end as the starting point, or particles will be generated. However, in the conveying method of the embodiment, the bonded wafer can be conveyed while being held by the second holding portion in contact with only the back side of the wafer W. As a result, a strong impact will not be applied to the end of the wafer W, thereby preventing the bonded wafer from peeling off or generating particles.

[0062] It should be noted that, in the above-mentioned conveying method, although the conveying action of the processed wafer is set after the conveying action of the processed wafer is set, the present invention is not limited to this. For example, the conveying action of the processed wafer can be set after the conveying action of the processed wafer is set. In addition, for example, the conveying action of the processed wafer and the conveying action of the processed wafer can be set at the same time.

[0063] The embodiments of the present invention should be considered in all respects as illustrative rather than restrictive. The above embodiments may be omitted, replaced, or modified in various ways without departing from the scope of the claims and the spirit thereof.

[0064] It should be noted that, in the above-mentioned embodiment, although the single-wafer type case where the processing system processes wafers one by one is described, the present invention is not limited thereto. For example, it may be a batch type where the processing system processes a plurality of wafers at a time. In addition, for example, it may be a semi-batch type where the processing system processes the wafers by causing the plurality of wafers disposed on the rotating table in the processing container to revolve through the area where the first gas is supplied and the area where the second gas is supplied in sequence.

[0065] In addition, in the above embodiment, although the object to be transported by the transport device 31 is described as a wafer W, the present invention is not limited thereto. For example, the object to be transported by the transport device 31 may be a large substrate for a flat panel display (FPD), a substrate for an organic EL flat panel, or a substrate for a solar cell.

[0066] This international application claims priority based on Japanese Patent Application No. 2020-008497 filed on January 22, 2020, and the entire contents of that application are cited in this international application.

[0067] Description of Reference Numerals

[0068] 1. Processing system

[0069] 20 Process Modules

[0070] 31 Conveying device

[0071] 100 Control device

[0072] 410 Multi-jointed Arm

[0073] 420 Pickup

[0074] 430 Restriction

[0075] 431 Restriction Wall

[0076] 440 Pressing and holding part

[0077] 441 Pressing Body

[0078] 442 Drive unit

[0079] 450 Elastomer

[0080] W Wafer

Claims

1. A conveying device, comprising: A first holding portion, which is used to contact with an end portion of the substrate to hold the substrate; a second holding portion formed of an elastic member and configured to hold the substrate by contacting only with the back surface of the substrate; and Control device, in, The control device is configured to control the conveying device in such a manner that a conveying speed in a state where the substrate is held by the first holding portion is greater than a conveying speed in a state where the substrate is held by the second holding portion. The first holding portion is provided at a position not in contact with the substrate held by the second holding portion, and the second holding portion is provided at a position not in contact with the substrate held by the first holding portion.

2. The conveying device according to claim 1, in, The first holding portion includes a first wall extending vertically, and a second wall provided apart from the first wall and extending vertically, and is configured such that when the substrate is held, the first wall and the second wall contact the end of the substrate to clamp the substrate. The second holding portion is configured to contact only the back surface of the substrate at a position closer to the center of the substrate than the end portion of the substrate when the substrate is clamped. The first holding portion and the second holding portion are configured to move integrally when the substrate is transported while being held.

3. The conveying device according to claim 1, in, The first holding portion holds the substrate at a position higher than a position at which the second holding portion holds the substrate.

4. The conveying device according to any one of claims 1 to 3, in, The first holding portion comprises: a restricting body that restricts the substrate so that it does not move in a horizontal direction; and The pressing body is provided separately from the restricting body and is movable so as to be in contact with the end of the substrate.

5. The conveying device according to any one of claims 1 to 3, in, A horizontal position of the substrate held by the first holding portion is different from a horizontal position of the substrate held by the second holding portion.

6. The conveying device according to any one of claims 1 to 3, in, A vertical position of the substrate held by the first holding portion is different from a vertical position of the substrate held by the second holding portion.

7. The conveying device according to any one of claims 1 to 3, in, A picker is also provided, which is connected to a conveying arm for conveying the substrate. The second holding portion includes a plurality of O-rings provided on an upper surface of the pickup.

8. The conveying device according to claim 7, in, The first holding portion is provided on the pickup.

9. The conveying device according to claim 7, in, The first holding portion is provided on the conveying arm and the picker.

10. The conveying device according to any one of claims 1 to 3, in, It also has a control device. The control device is configured to control the transport device so that the substrate is held by the first holding portion or the second holding portion according to the type of the substrate.

11. The conveying device according to any one of claims 1 to 3, in, The conveying device is arranged in the atmospheric conveying chamber.

12. A processing system, include: a processing chamber for accommodating a substrate therein and processing the substrate; as well as a conveying device for conveying the substrate contained in the processing chamber, The above-mentioned conveying device has: A first holding portion, which is used to contact with an end portion of the substrate to hold the substrate; a second holding portion formed of an elastic member and configured to hold the substrate by contacting only with the back surface of the substrate; and A control device, wherein The control device is configured to control the conveying device in such a manner that a conveying speed in a state where the substrate is held by the first holding portion is greater than a conveying speed in a state where the substrate is held by the second holding portion. The first holding portion is provided at a position not in contact with the substrate held by the second holding portion, and the second holding portion is provided at a position not in contact with the substrate held by the first holding portion.

13. A method of conveying, comprising the following steps: Acquiring a conveying mode, the conveying mode including information on whether the substrate can be held at the end and information on whether the substrate can be conveyed at a high speed; Based on the obtained conveying mode, determining whether to hold the substrate by contacting with an end of the substrate or to hold the substrate by contacting only with a back surface of the substrate; When it is determined that the substrate is held by contacting with the end of the substrate, an action of bringing the first holding portion into contact with the end of the substrate to hold the substrate is performed; and When it is determined that the substrate is held by contacting only the back surface of the substrate, an action is performed to make a second holding portion different from the first holding portion contact only the back surface of the substrate to hold the substrate, in, The first holding unit and the second holding unit are controlled so that a conveying speed in a state where the substrate is held by the first holding unit is greater than a conveying speed in a state where the substrate is held by the second holding unit.

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