Substrate conveyance device and cooling method for arm

Abstract

The present disclosure relates to a substrate conveyance device and a cooling method for an arm. A substrate conveyance device for conveying a substrate includes: a conveyance arm having a substrate support portion for supporting the substrate and an arm linked to the substrate support portion for moving the substrate support portion; a cooling mechanism that supplies cooling fluid from a fluid supply source to each of a plurality of cooling target regions of the arm; a measurement portion that measures the temperature of each of the cooling target regions; and a control portion that, for each of the cooling target regions, calculates a thermal index based on the amount of change in the temperature of the cooling target region measured by the measurement portion with respect to a reference temperature and the degree to which the temperature of the cooling target region affects the movement accuracy of the substrate support portion, and that determines the distribution ratio at which the cooling mechanism distributes the cooling fluid from the fluid supply source based on the thermal index.

Description

Technical Field

[0001] This disclosure relates to a substrate conveying device and a cooling method for the arm. Background Technology

[0002] Patent Document 1 discloses an industrial robot for transporting objects in a vacuum. This industrial robot includes a hand for carrying the object, a hollow arm connected to the hand at its front end, and a cooling mechanism for cooling the interior of the arm. The hand and arm are positioned in a vacuum. The arm has multiple hollow arm sections connected to each other in a manner that allows relative rotation. The interior of each arm section is at atmospheric pressure. A temperature sensor for measuring the internal temperature of each arm section is disposed within its respective section. The cooling mechanism includes a cooling air supply port disposed within each arm section, and adjusts the amount of cooling air supplied from the supply port based on the temperature sensor readings, thereby individually cooling the interior of each arm section.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2015-37701 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] The technology disclosed herein efficiently cools the arm in a substrate conveying apparatus, thereby suppressing a decrease in the movement accuracy of the substrate support.

[0008] Solution for solving the problem

[0009] One aspect of this disclosure is a substrate conveying apparatus for conveying a substrate, the substrate conveying apparatus comprising: a conveying arm having a substrate support portion for supporting the substrate, and an arm connected to the substrate support portion for moving the substrate support portion; a cooling mechanism that distributively supplies cooling fluid from a fluid supply source to each of a plurality of cooling target areas of the arm; a measuring unit that measures the temperature of each of the cooling target areas; and a control unit, wherein the control unit calculates a thermal index for each cooling target area based on the amount of change in temperature of the cooling target area measured by the measuring unit relative to a reference temperature and the degree of influence of the temperature of the cooling target area on the movement accuracy of the substrate support portion, and the control unit determines the distribution ratio of the cooling fluid from the fluid supply source distributed by the cooling mechanism based on the thermal index.

[0010] The effects of the invention

[0011] According to this disclosure, the arm can be cooled efficiently in the substrate conveying device, thereby suppressing the decrease in the movement accuracy of the substrate support. Attached Figure Description

[0012] Figure 1 This is a top view showing the outline of the structure of a wafer processing system having a vacuum conveying apparatus, which is the substrate conveying apparatus according to this embodiment.

[0013] Figure 2 This is a schematic longitudinal cross-sectional view illustrating a structural example of a wafer transport mechanism.

[0014] Figure 3 This is a graph used to illustrate the effect αn of the temperature of the cooled object area on the movement accuracy of the fork.

[0015] Figure 4 This is a flowchart illustrating a specific example of the cooling process for the arm.

[0016] Figure 5 This is a top view schematically illustrating another example of the structure of a vacuum conveying device.

[0017] Figure 6 This is a longitudinal cross-sectional view schematically illustrating another example of the structure of a wafer transport mechanism. Detailed Implementation

[0018] For example, in the manufacturing process of semiconductor devices, a substrate processing apparatus performs prescribed processes such as film deposition and etching on substrates such as semiconductor wafers (hereinafter referred to as "wafers"). The above-mentioned processes are performed in a processing apparatus having a mounting stage for placing the substrate, and a substrate transport apparatus is used for moving the substrate into and out of the processing apparatus.

[0019] The substrate conveying device includes a conveying arm, which has a substrate support portion such as a fork for supporting the substrate, and an arm connected to the fork for moving the fork. The conveying arm is, for example, a multi-joint arm, capable of moving the fork by bending and extending.

[0020] In addition, in order to obtain appropriate processing results such as uniform processing results within the substrate surface, the substrate needs to be accurately aligned and placed on the mounting stage. Therefore, it is necessary to move the fork relative to the mounting stage with high precision.

[0021] Furthermore, sometimes high-temperature substrates are transported by substrate conveying devices. In such cases, the drive mechanism used to drive the movement of the fork, i.e., the bending and stretching of the conveying arm, is heated by radiant heat from the high-temperature substrate, which can sometimes reduce the accuracy of the fork's movement. For example, the degree of meshing of the gears in the drive mechanism may vary depending on the temperature, which can sometimes also reduce the accuracy of the fork's movement.

[0022] Furthermore, it is required that the fork move at high speed to process the substrate with high throughput. However, when the fork moves at high speed, the motor of the drive mechanism, which is the drive source for the movement of the fork, heats up, and the gears are heated by this heat, which sometimes reduces the movement accuracy of the fork.

[0023] Within the arm, there are multiple locations where temperature variations can affect the fork's movement accuracy. As a method to suppress a decrease in fork movement accuracy, the following approach is considered: measuring the temperature of each of these multiple locations and supplying each location with cooling air at a flow rate corresponding to the measured value. However, in this method, when limiting the maximum total flow rate of the cooling air to reduce costs (i.e., energy saving), sufficient cooling may not be achieved, leading to a decrease in fork movement accuracy. In other words, there is room for improvement in the efficiency of arm cooling with this method.

[0024] Therefore, the technology disclosed herein efficiently cools the arm in the substrate conveying apparatus, thereby suppressing the decrease in the movement accuracy of the substrate support.

[0025] The substrate conveying apparatus and cooling method of the arm according to this embodiment will now be described with reference to the accompanying drawings. Furthermore, in this specification and the accompanying drawings, elements having substantially the same functional structure are labeled with the same reference numerals, thereby omitting repeated descriptions.

[0026] <Wafer Processing System>

[0027] Figure 1 This is a top view showing the outline of the structure of the wafer processing system 1, which includes a vacuum conveying apparatus that serves as the substrate conveying apparatus according to this embodiment.

[0028] Figure 1 The wafer processing system 1 is a system that performs prescribed processes on a wafer W, which serves as a substrate, such as film deposition, diffusion, and etching, under reduced pressure.

[0029] The wafer processing system 1 has a structure that connects a carrier station 10 and a processing station 11 into one unit. The carrier station 10 is used to load and unload a carrier C capable of accommodating multiple wafers W. The processing station 11 has multiple processing devices for performing the aforementioned processing on the wafers W under reduced pressure. The carrier station 10 and the processing station 11 are connected via two loading interlocking devices 12 and 13.

[0030] Loading interlock devices 12 and 13 have loading interlock chambers 12a and 13a configured to switch between atmospheric pressure and vacuum conditions. Loading interlock devices 12 and 13 are configured to connect the atmospheric pressure conveying device 20 (described later) to the vacuum conveying device 30, which serves as a substrate conveying device.

[0031] The carrier station 10 includes an atmospheric pressure conveying device 20 and a carrier placement stage 21. Additionally, the carrier station 10 may also include an alignment device (not shown) for adjusting the orientation of the wafer W.

[0032] The atmospheric pressure transport device 20 has an atmospheric transport chamber 22 whose interior is set to atmospheric pressure. The atmospheric transport chamber 22 is connected to the loading interlock chambers 12a and 13a of the loading interlock devices 12 and 13 via gate valves (not shown). A transport mechanism 23 is provided inside the atmospheric transport chamber 22. The transport mechanism 23 is configured to transport the wafer W between the loading interlock chambers 12a and 13a under atmospheric pressure.

[0033] The conveying mechanism 23 includes a conveying arm 23a for supporting the wafer W during conveying, a rotary table 23b for supporting the conveying arm 23a in a manner that allows the conveying arm 23a to rotate, and a base 23c on which the rotary table 23b is mounted. Additionally, a guide rail 23d extending along the length of the atmospheric conveying chamber 22 is provided inside the atmospheric conveying chamber 22. The base 23c is mounted on the guide rail 23d in a manner that allows the conveying mechanism 23 to move along the guide rail 23d.

[0034] The carrier platform 21 is located on the side of the atmospheric pressure conveying device 20 opposite to the loading interlocking devices 12 and 13. In the illustrated example, the carrier platform 21 can hold multiple, for example, five carriers C. The conveying arm 23a of the conveying mechanism 23 of the atmospheric pressure conveying device 20 moves the wafer W placed in the carrier C on the carrier platform 21 into and out of the atmospheric conveying chamber 22.

[0035] The processing station 11 has a vacuum conveying device 30 and processing devices 40-43.

[0036] The vacuum transport apparatus 30 has a vacuum transport chamber 31 in which the chamber is maintained in a depressurized state (vacuum state). The vacuum transport chamber 31 is connected to the loading interlock chambers 12a and 13a of the loading interlock devices 12 and 13 via gate valves (not shown). Furthermore, the vacuum transport chamber 31 is connected to the vacuum processing chambers 44 to 47 (described later) via gate valves G1 to G4, respectively. A wafer transport mechanism 32, serving as a substrate transport mechanism for transporting wafers W, is provided within the vacuum transport chamber 31. The wafer transport mechanism 32 is used to transport wafers W into and out of the processing apparatuses 40 to 43. The wafer transport mechanism 32 includes a transport arm 32a, which has an arm 302 and a fork 301 serving as a substrate support. The fork 301 supports the wafer W. The arm 302 is connected to the fork 301 to move the fork 301. Details of the structure of the wafer transport mechanism 32 will be described later.

[0037] Processing apparatuses 40-43 perform prescribed processes on wafer W under reduced pressure, such as film deposition, diffusion, and etching. Furthermore, processing apparatuses 40-43 each have vacuum processing chambers 44-47 for performing the aforementioned prescribed processes on wafer W under reduced pressure.

[0038] Furthermore, the wafer processing system 1 includes a control device 50. The control device 50 includes a control unit 51 and a display unit 52.

[0039] The control unit 51 includes, for example, a computer equipped with a processor such as a CPU, memory, etc., and has a storage unit (not shown) for storing various information. The storage unit stores programs for controlling wafer processing of the wafer processing system 1 and programs for controlling the cooling process of the arm 302. Alternatively, the programs may be recorded on a computer-readable storage medium and installed from that storage medium to the control unit 51. Furthermore, the storage medium may be a transient or non-transient storage medium. Part or all of the program may also be implemented using dedicated hardware (circuit board).

[0040] The display unit 52 is used to display various information and is composed of display devices such as liquid crystal displays and organic displays.

[0041] <Wafer Processing>

[0042] Next, an example of wafer processing using the wafer processing system 1 configured as described above will be described. Furthermore, the following processing is performed under the control of the control unit 51.

[0043] First, the wafer W is removed from the carrier C by the transfer arm 23a of the transfer mechanism 23, and the atmospheric gate valve (not shown) for the loading interlock device 12 is set to the open state. Then, the wafer W is moved into the loading interlock device 12 by the transfer arm 23a.

[0044] Next, the gate valve is set to the closed state to seal the loading interlock device 12 and reduce the pressure.

[0045] When the pressure inside the loading interlock device 12 falls below the specified pressure, the gate valve (not shown) on the vacuum atmosphere side is set to the open state, and the wafer W is received from the loading interlock device 12 by the conveying arm 32a of the wafer conveying mechanism 32. The wafer W is then removed from the loading interlock device 12 and moved into the vacuum conveying chamber 31.

[0046] Next, after closing the aforementioned gate valve, the gate valve for the processing unit used for target processing (here, gate valve G1 for processing unit 40) is opened. Then, the wafer W is moved into the processing unit 40 by the transfer arm 32a. Afterward, gate valve G1 is closed, and the wafer W is processed as desired in the processing unit 40.

[0047] After the desired processing is completed, the gate valve G1 is opened, and the wafer W is removed from the processing unit 40 by the conveying arm 32a of the wafer conveying mechanism 32. Then, the wafer W is removed from the vacuum conveying chamber 31 in the reverse process of moving the wafer W into the vacuum conveying chamber 31, thus completing a series of wafer processing steps.

[0048] <Wafer Transfer Mechanism>

[0049] Next, use Figure 2 To illustrate an example of wafer transport mechanism 32. Figure 2 This is a schematic longitudinal cross-sectional view illustrating a structural example of the wafer transport mechanism 32.

[0050] Wafer transport mechanism 32 Figure 2 As shown, it has a conveying arm 32a. In this example, the wafer conveying mechanism 32 has one conveying arm 32a, but it can also have multiple arms. The conveying arm 32a is, for example, a multi-joint arm, and as described above, the conveying arm 32a has a fork 301 for supporting the wafer W, and an arm 302 connected to the fork 301 for moving the fork 301.

[0051] Arm 302, for example, has a first arm 311 and a second arm 312. The first arm 311 and the second arm 312 each have a cuboid shell 313 and 314. The shells 313 and 314 are hollow and their interiors are set to a non-vacuum atmosphere.

[0052] The fork 301 holds the wafer W at its front end. The fork 301 is connected to the front end of the first arm 311 in a manner that allows it to rotate freely horizontally around its base end. Specifically, a columnar shaft portion 320, serving as a joint axis, is provided extending vertically downward from the lower surface of the base end of the fork 301. The shaft portion 320 is rotatably connected to the front end of the first arm 311. The front end of the shaft portion 320 is inserted into the housing 313 of the first arm 311. Alternatively, multiple forks 301 may be provided for the first arm 311.

[0053] A sealing mechanism 330 is provided on the upper part of the front end side of the first arm 311. The sealing mechanism 330 airtightly seals the shaft portion 320 of the fork 301 between the shaft portion 320 and the housing 313, and supports the shaft portion 320 in a manner that allows the shaft portion 320 to rotate. The sealing mechanism 330 has, for example, a sealing member made of resin.

[0054] The first arm 311 is rotatably connected to the front end of the second arm 312 with its base end side as an axis. Specifically, a cylindrical shaft portion 340, serving as a joint axis, is provided extending vertically downward from the lower surface of the base end side of the housing 313 of the first arm 311. The shaft portion 340 is rotatably connected to the front end of the second arm 312. The front end of the shaft portion 340 is connected to the interior of the housing 314 of the second arm 312. The interior of the housing 313 of the first arm 311 and the interior of the housing 314 of the second arm 312 are connected via the hollow portion of the cylindrical shaft portion 340.

[0055] A sealing mechanism 350 is provided on the upper part of the front end side of the second arm 312. The sealing mechanism 350 airtightly seals the shaft portion 340 of the first arm 311 and the housing 314, and supports the shaft portion 340 in a manner that allows the shaft portion 340 to rotate. The sealing mechanism 350 has, for example, a sealing member made of resin.

[0056] The second arm 312 is connected to the cylindrical lifting shaft 360 in a manner that allows it to rotate freely around its base end. Specifically, the cylindrical lifting shaft 360, which serves as a joint axis, is provided through the bottom wall of the housing 314 of the second arm 312, and is configured to allow the housing 314 to rotate around the lifting shaft 360. The base end of the lifting shaft 360 is located inside the housing 314 of the second arm 312, and the front end of the lifting shaft 360 penetrates the bottom wall 31a of the vacuum transfer chamber 31.

[0057] Additionally, a sealing mechanism 370 is provided at the lower base of the second arm 312. This sealing mechanism 370 airtightly seals the front end of the lifting shaft 360 and the housing 314, and supports the housing 314 on the lifting shaft 360. The sealing mechanism 370 may have, for example, a magnetic fluid seal.

[0058] The lifting shaft 360 is equipped with a drive mechanism 380 for driving the lifting of the lifting shaft 360. The drive mechanism 380 has a drive source such as a motor that generates a driving force for the lifting of the lifting shaft 360. By raising and lowering the lifting shaft 360, the second arm 312 is raised and lowered, thereby raising and lowering the conveying arm 32a.

[0059] In addition, a bellows 390 is provided to airtightly seal the gap between the lifting shaft 360 and the bottom wall 31a of the vacuum conveying chamber 31.

[0060] In addition, the interior of the housing 314 of the second arm 312 is connected to the exterior of the vacuum transport chamber 31 in a non-vacuum atmosphere (e.g., atmospheric atmosphere) via the hollow portion of the cylindrical lifting shaft 360.

[0061] Furthermore, the conveying arm 32a includes drive mechanisms 401 to 403, which drive the flexion and extension of the conveying arm 32a by driving relative rotation between the parts connected via joint shafts such as the shaft portion 340. Drive mechanism 401 is disposed inside the housing 313 of the first arm 311, and drive mechanisms 402 and 403 are disposed inside the housing 314 of the second arm 312.

[0062] The drive mechanism 401 specifically drives the rotation of the fork 301. More specifically, the drive mechanism 401 drives the rotation of the shaft portion 320 disposed on the fork 301. The drive mechanism 401 has a motor 411 that generates a driving force for the rotation of the shaft portion 320, and a gear unit 412 having a plurality of gears that transmit the driving force of the motor 411 to the shaft portion 320. The gear unit 412 is connected to the shaft portion 320, for example, via a timing belt (not shown).

[0063] The drive mechanism 402 specifically drives the rotation of the first arm 311. More specifically, the drive mechanism 402 drives the rotation of the shaft 340 disposed on the first arm 311. The drive mechanism 402 has a motor 421 that generates a driving force for the rotation of the shaft 340, and a gear unit 422 having a plurality of gears that transmit the driving force of the motor 421 to the shaft 340. The gear unit 422 is connected to the shaft 340, for example, via a timing belt (not shown).

[0064] The drive mechanism 403 specifically drives the rotation of the second arm 312. More specifically, the drive mechanism 403 drives the rotation of the second arm 312 about the lifting shaft 360. The drive mechanism 403 has a motor 431 that generates a driving force for the rotation of the second arm 312, and a gear unit 432 having a plurality of gears that transmit the driving force of the motor 431 to the lifting shaft 360. The gear unit 432 is connected to the lifting shaft 360, for example, via a timing belt (not shown).

[0065] Motors 411, 421, and 431 are controlled by the control unit 51.

[0066] In addition, the arm 302 of the conveying arm 32a is configured with m (m is a natural number greater than 2. In this example, m = 3), that is, multiple cooling target areas R.

[0067] A drive mechanism 401 is provided in the cooling target area R1, and a sealing mechanism 330 faces the cooling target area R1. A drive mechanism 402 is provided in the cooling target area R2, and a sealing mechanism 350 faces the cooling target area R2. A drive mechanism 403 is provided in the cooling target area R3, and a sealing mechanism 370 faces the cooling target area R3.

[0068] Furthermore, the wafer transport mechanism 32 has a cooling mechanism 500 capable of individually cooling each cooling target area R. The cooling mechanism 500 supplies compressed gas, which serves as a cooling fluid, from the compressed gas source 501, which serves as a fluid supply source, to each cooling target area R in a distributed manner.

[0069] The cooling mechanism 500 has distribution pipes 511 to 513 for each cooling target area R, with a compressed gas source 501 provided at the front end.

[0070] The drive mechanism 401 and the sealing mechanism 330 are cooled by compressed gas ejected from the above-mentioned nozzle of the distribution pipe 511. For example, the distribution pipe 511 is configured in such a way that the compressed gas from the above-mentioned nozzle is directly blown to the gear unit 412, which has the greatest impact on the movement accuracy of the fork 301 (i.e. the transport accuracy of the wafer W) in the cooling target area R1.

[0071] The drive mechanism 402 and the sealing mechanism 350 are cooled by compressed gas ejected from the aforementioned nozzle of the distribution pipe 512. For example, the distribution pipe 512 is configured such that the compressed gas from the aforementioned nozzle is directly blown to the gear unit 422, which has the greatest impact on the movement accuracy of the fork 301 within the cooling target area R2.

[0072] The drive mechanism 403 and the sealing mechanism 370 are cooled by compressed gas ejected from the aforementioned nozzle of the distribution pipe 513. For example, the distribution pipe 513 is configured such that the compressed gas from the aforementioned nozzle is directly blown to the gear unit 432, which has the greatest impact on the movement accuracy of the fork 301 within the cooling target area R3.

[0073] Furthermore, the compressed gas ejected from the distribution pipes 511-513 passes through the interior of the arm 302 and is released to the non-vacuum atmosphere outside the vacuum transport chamber 31 via the hollow portion of the lifting shaft 360.

[0074] Additionally, the base ends of distribution pipes 511-513 merge and connect to the front end of main pipe 520. The base end of main pipe 520 is connected to compressed gas source 501.

[0075] As described below, the control unit 51 determines the distribution ratio of the cooling fluid. Flow adjustment device groups 531 to 533 are respectively provided in the distribution pipes 511 to 513, so that the cooling mechanism 500 can supply compressed gas from the compressed gas source 501 to each cooling target area R1 to R3, etc., according to the cooling fluid distribution ratio determined by the control unit 51. The flow adjustment device groups 531 to 533 include, for example, flow adjustment valves (not shown) for adjusting the flow rate and on / off valves (not shown) for switching the supply / stop of compressed fluid.

[0076] The main pipe 520 is equipped with an on / off valve 540 for switching the supply / stop of compressed fluid to the distribution pipes 511-513.

[0077] The flow adjustment equipment group 531-533 and the on / off valve 540 are controlled by the control unit 51.

[0078] In addition, the wafer transport mechanism 32 includes temperature sensors 551 to 553 as measuring units for measuring the temperature of each of the cooling target areas R1 to R3. Specifically, the wafer transport mechanism 32 has a temperature sensor 551 for measuring the temperature of the cooling target area R1, a temperature sensor 552 for measuring the temperature of the cooling target area R2, and a temperature sensor 553 for measuring the temperature of the cooling target area R3. The measurement results of the temperature sensors 551 to 553 are output to the control unit 51.

[0079] <Arm Cooling Method>

[0080] In this embodiment, the control unit 51 determines the allocation ratio of compressed gas from the compressed gas source 501 to each of the multiple cooling target areas R.

[0081] Specifically, the control unit 51 determines the above distribution ratio based on the following thermal index P.

[0082] For each cooling target area R1 to R3, the thermal index P is calculated based on the following (1) and (2):

[0083] (1) The change in temperature Tn of the cooling target area Rn (n is any one of 1, 2, or 3) relative to the reference temperature To, as measured by temperature sensor 551, etc.; and

[0084] (2) The influence of the temperature of the cooling object area Rn on the moving accuracy of the fork 301, αn.

[0085] The reference temperature To is the temperature at which the wafer transport mechanism 32 is assembled, for example, room temperature.

[0086] Figure 3 This is a graph used to illustrate the aforementioned influence αn.

[0087] The figure shows the fully extended state of the transport arm 32a in the wafer processing system 1. The movement accuracy (i.e., the transport accuracy of the wafer W) of the moving fork 301 by the arm 302 is worst in this fully extended state of the transport arm 32a. Furthermore, when the cooling target area Rn becomes too hot, causing abnormalities in the gears or other components of the drive mechanism of that cooling target area Rn, the cooling target area R3, which is located furthest from the fork 301, has the greatest impact on the movement accuracy of the fork 301. On the other hand, the cooling target area R1, which is located closest to the fork 301, has the least impact. In the fully extended state of the transport arm 32a, the cooling target area R2 is farther from the fork 301 than the cooling target area R1 is closer to the fork 301 than the cooling target area R3 is closer to the fork 301. Moreover, the influence of the cooling target area R2 on the movement accuracy of the fork 301 is greater than that of the cooling target area R1 and less than that of the cooling target area R3.

[0088] Therefore, in this embodiment, for example, the influence degree αn of the cooling target region Rn is preset based on the distance Ln from the fork 301 to the cooling target region Rn when the conveyor arm 32a is in its most extended state in the wafer processing system 1.

[0089] For example, the aforementioned influence degree α1 of the cooling target area R1 is preset based on the distance L1 from the fork 301 (the designed position at the center of the wafer W placed on the fork 301) to the cooling target area R3 (the central axis of the shaft portion 320, which is the joint axis corresponding to the cooling target area R3) when the conveyor arm 32a is in its most extended state in the wafer processing system 1.

[0090] For example, the aforementioned influence degree α2 of the cooling target area R2 is preset based on the distance L2 from the fork 301 (the designed position of the center of the wafer W placed on the fork 301) to the cooling target area R2 (the central axis of the shaft portion 340 of the joint axis corresponding to the cooling target area R2) in the most extended state of the conveyor arm 32a in the wafer processing system 1.

[0091] For example, the aforementioned influence degree α3 of the cooling target area R3 is preset based on the distance L3 from the fork 301 (the designed position at the center of the wafer W placed on the fork 301) to the cooling target area R3 (the central axis of the shaft portion 360 of the joint axis corresponding to the cooling target area R3) in the most extended state of the conveyor arm 32a in the wafer processing system 1.

[0092] More specifically, for example, the influence degree α1 to α3 of the cooling target areas R1 to R3 is preset as follows.

[0093] α1=L1 / L1=1

[0094] α2=L2 / L1

[0095] α3=L3 / L1

[0096] The control unit 51 calculates the thermal index Pn of the cooling target area Rn based on the change ΔTn of the temperature Tn of the cooling target area Rn relative to the reference temperature To and the aforementioned influence degree αn of the cooling target area Rn.

[0097] For example, the thermal index Pn can be calculated based on the following formula.

[0098] Pn=αn×ΔTn

[0099] Then, as described above, the control unit 51 determines the distribution ratio of compressed gas from the compressed gas source 501 for each of the multiple cooling target areas R1 to R3 based on the aforementioned thermal index Pn.

[0100] Specifically, the control unit 51 determines the aforementioned allocation ratio to preferentially supply compressed gas to the cooling target region Rn, which has the highest thermal index Pn. More specifically, the control unit 51 determines the aforementioned allocation ratio, for example, to make the thermal index Pn equal across the cooling target regions Rn.

[0101] More specifically, the control unit 51 stores in advance in the storage unit (not shown) a table that corresponds the thermal indices P1 to P3 of each of the cooling target areas R1 to R3 to the above-mentioned allocation ratio, and the control unit 51 determines the allocation ratio based on the calculated thermal index Pn and the above-mentioned table.

[0102] The cooling mechanism 500 supplies compressed gas from the compressed gas source 501 in a distribution ratio determined in this way. Thus, the cooling arm 302.

[0103] Furthermore, the control unit 51 can also determine whether the temperature Tn measured by the temperature sensor 551 or the like in each of the multiple cooling target areas R1 to R3 is lower than a threshold (e.g., 80% of the allowable temperature) X determined based on the allowable temperature Tp of the cooling target area R. The allowable temperature Tp is determined based on the heat resistance temperature of the components located in the cooling target area Rn and the components facing the cooling target area Rn (specifically, the heat resistance temperatures of the sealing mechanisms 330, 350, and 370). In addition, the allowable temperature Tp is determined based on the upper limit of the operating temperature guarantee temperature of the gear units 412, 422, and 432. The allowable temperature Tp and the threshold X based on the allowable temperature Tp can also be different for each cooling target area R.

[0104] Furthermore, the method of supplying compressed gas from the cooling unit 500 can be changed based on the determination result related to the threshold X based on the allowable temperature Tp.

[0105] For example, if the measured temperature Tn of all cooling target areas R1 to R3 is lower than the threshold X determined based on the allowable temperature Tp of the cooling target area Rn, the cooling mechanism 500 supplies compressed gas in a distribution ratio determined as described above.

[0106] In addition, for example, if the temperature measured in only a portion of the cooling target area R is higher than the aforementioned threshold X, the cooling mechanism 500 preferentially supplies compressed gas to that portion of the cooling target area R, i.e., the high-temperature cooling target area R.

[0107] <Specific example of cooling treatment for arm 302>

[0108] Next, a more specific example of the cooling process for arm 302 will be given. Figure 4 This is a flowchart illustrating a specific example of the cooling process for arm 302.

[0109] (Step S1)

[0110] First, under the control of the control unit 51, the temperatures T1 to T3 of each of the multiple cooling target areas R1 to R3 of the arm 302 are measured by temperature sensors 551 to 553. These temperature measurements are performed at predetermined intervals, for example, every specified time interval.

[0111] (Step S2)

[0112] Next, the control unit 51 determines whether the temperature Tn of the cooling target area Rn is lower than the first threshold (e.g., 80% of the allowable temperature) X1 determined based on the allowable temperature Tp in all cooling target areas R1 to R3.

[0113] (Step S3)

[0114] If, in step S2, it is determined that the temperature Tn is lower than the first threshold X1 in all cooling target areas R1 to R3 (the case of "Yes"), the control unit 51 calculates the thermal index Pn as follows: That is, for each cooling target area R1 to R3, the control unit 51 calculates the thermal index Pn based on the change ΔTn of the measured temperature Tn of the cooling target area Rn relative to the reference temperature To and the degree of influence αn of the temperature of the cooling target area Rn on the movement accuracy of the fork 301.

[0115] (Step S4)

[0116] Next, the control unit 51 determines the distribution ratio of compressed gas from the compressed gas source 501 to the cooling mechanism 500 based on the thermal index Pn calculated for each cooling target area R1 to R3, that is, all thermal indices based on thermal indices P1, P2, and P3.

[0117] (Step S5)

[0118] Then, under the control of the control unit 51, the cooling mechanism 500 supplies compressed gas from the compressed gas source 501 to each cooling target area R1 to R3 according to the determined distribution ratio. Specifically, the control unit 51 controls the flow adjustment device groups 531 to 533 to supply compressed gas from the compressed gas source 501 to the cooling target areas R1 to R3 according to the determined distribution ratio.

[0119] Then, the process returns to step S1.

[0120] Alternatively, if the temperature Tn of all the cooling target areas R1 to R3 is low enough that cooling is not required, the control unit 51 controls the on / off valve 540 to stop supplying compressed gas from the compressed gas source 501 to the cooling target areas R1 to R3.

[0121] Alternatively, a flow regulating valve can be installed in the main pipe 520. When the temperature Tn of all cooling target areas R1 to R3 is relatively low and close to the aforementioned reference temperature To, the control unit 51 controls the flow regulating valve installed in the main pipe 520 to reduce the total flow rate of compressed gas from the compressed gas source 501, that is, the gas supplied to the distribution pipes 511 to 513.

[0122] (Step S6)

[0123] In addition, if in step S2 it is determined that the temperature Tn of any cooling target area R1 to R3 is above the first threshold X1 (in the case of "No"), the control unit 51 determines whether the temperature Tn of the cooling target area Rn in all cooling target areas R1 to R3 is lower than the second threshold (e.g., 90% of the allowable temperature) X2, which is greater than the first threshold X1.

[0124] (Step S7)

[0125] In step S6, if it is determined that the temperature Tn of all cooling target areas R1 to R3 is lower than the second threshold X2 (the "yes" case), under the control of the control unit 51, the cooling mechanism 500 preferentially supplies compressed gas from the compressed gas source 501 to the cooling target areas Rn where the temperature Tn is above the first threshold X1 and below the second threshold X2. Specifically, for example, the control unit 51 controls the flow adjustment device groups 521 to 523 to supply compressed gas from the compressed gas source 501 only to the cooling target areas Rn where the temperature Tn is above the first threshold X1 and below the second threshold X2.

[0126] Furthermore, if the temperature Tn of the entire cooling target area Rn is above the first threshold X1 and below the second threshold X2, the same process as steps S3 to S5 may be performed.

[0127] Then, the process returns to step S1.

[0128] (Step S8)

[0129] Furthermore, if in step S6 it is determined that the temperature Tn of any cooling target area Rn is above the second threshold X2 (the case of "No"), that is, if the temperature of the conveying arm 32a (specifically the internal temperature of the arm 302) is too high, the control unit 51 lowers the moving speed of the fork 301 from the arm 302 to the normal speed. Specifically, the control unit 51, for example, lowers the upper limit of the moving speed of the fork 301 to the upper limit of the normal speed. The normal speed is, for example, the moving speed of the fork 301 when, in step S2 it is determined that the temperature Tn of all cooling target areas R1 to R3 is below the first threshold X1. As a result, the heat generated by the motors 411, 421, and 431 of the drive mechanisms 401 to 403 can be suppressed.

[0130] (Step S9)

[0131] In addition to the control unit 51 reducing the moving speed of the fork 301, the cooling mechanism 500 also prioritizes supplying compressed gas from the compressed gas source 501 to the cooling target area Rn where the temperature Tn is above the second threshold value X2, under the control of the control unit 51. Specifically, for example, the control unit 51 controls the flow adjustment device groups 521 to 523 to supply compressed gas from the compressed gas source 501 only to the cooling target area Rn where the temperature Tn is above the second threshold value X2.

[0132] Furthermore, if the temperature Tn of the entire cooling target area Rn is above the second threshold X2, for example, all operations of the wafer transport mechanism 32 may be stopped.

[0133] Then, the process returns to step S1.

[0134] <Main Effects of This Implementation Method>

[0135] As described above, in the present embodiment, the control unit 51 calculates a heat index Pn for each cooling target region R1 to R3 based on the change amount ΔTn of the measured temperature Tn of the cooling target region Rn with respect to the reference temperature To and the influence degree αn of the temperature of the cooling target region Rn on the movement accuracy of the fork 301. In addition, the control unit 51 determines the distribution ratio of the compressed gas supplied from the compressed gas source 501 to the cooling mechanism 500 based on the heat index Pn calculated for each cooling target region R1 to R3. Therefore, even if the supply amount of the compressed gas from the compressed gas source 501 is restricted for energy saving, the arm 302 can be efficiently cooled so that the movement accuracy of the fork 301 does not decrease.

[0136] In addition, in the present embodiment, when the measured temperature Tn in any one of the cooling target regions R1 to R3 is equal to or higher than the first threshold X1 determined based on the allowable temperature Tp and lower than the second threshold X2, the compressed gas from the compressed gas source 501 is not supplied at the distribution ratio determined as described above, but the compressed gas from the compressed gas source 501 is preferentially supplied to the cooling target region Rn where X1 ≤ Tn < X2. Therefore, it is possible to more reliably suppress the temperature of the cooling target regions R1 to R3 from exceeding the allowable temperature Tp. As a result, it is possible to more reliably prevent the resin sealing members of the sealing mechanisms 330 and 350 from being damaged abnormally and breaking the vacuum of the vacuum transfer chamber 31, or prevent the gear unit 412 of the drive mechanism 401 from malfunctioning and causing the wafer W to fall from the transfer arm 32a.

[0137] In addition, in the present embodiment, when the measured temperature Tn in any one of the cooling target regions R1 to R3 is equal to or higher than the second threshold X2, the control unit 51 reduces the movement speed of the fork 301 below the normal speed to suppress the heat generation from the motors 411, 421, and 431. Therefore, by supplying compressed gas to the cooling target region Rn where the temperature Tn is equal to or higher than the second threshold X2, it is possible to more reliably suppress the temperature of the cooling target regions R1 to R3 from exceeding the allowable temperature Tp.

[0138] <Variation of Step S8>

[0139] In the above example, when the temperature Tn in any one of the cooling target regions Rn is equal to or higher than the second threshold X2, that is, when the temperature inside the arm 302 is too high, the control unit 51 uniformly reduces the movement speed of the fork 301 below the normal speed.

[0140] Alternatively, when the temperature inside the arm 302 is too high, the control unit 51 sets the movement speed of the fork 301 to the normal speed at a specific time and reduces the movement speed of the fork 301 below the normal speed at other times.

[0141] The term "specific time" refers to situations such as when the fork 301 supports a wafer W at a temperature higher than a specified temperature (e.g., 50°C), or when the fork 301 enters or exits from any of the processing apparatuses 40-43, where the internal temperature is higher than the specified temperature (e.g., 50°C). The term "other than specific time" refers to situations such as when the fork 301 supports a wafer W at a temperature lower than a specified temperature, or when the fork 301 is moving towards a position where it enters or exits from a high-temperature transport destination.

[0142] Alternatively, if the internal temperature of the arm 302 is too high, the control unit 51 may cause the fork 301 to stop for a predetermined time (e.g., 5 to 10 seconds or more) after each series of actions.

[0143] Alternatively, if the internal temperature of the arm 302 is too high, the fork 301 can be stopped moving after it has been brought into a thermally favorable state.

[0144] "A thermally advantageous state" is, for example, a state in which the conveyor arm 32a is folded and the fork 301 leaves the processing apparatus 40-43, which serves as the conveying destination or source of the wafer W and has a high internal temperature.

[0145] In addition, when the fork 301 supports a wafer W with a temperature higher than the specified temperature, the "thermally advantageous state" can also be the state in which the fork 301 retreats from the transport destination after the high-temperature wafer W is handed over to the transport destination such as the loading interlock device 12.

[0146] In such Figure 5 When a cooling section 600, which is cooled by a cooling medium, is provided in the vacuum transfer chamber 31 as shown, the "thermally advantageous state" can also be that the arm 302 faces the cooling section 600.

[0147] Furthermore, as an exhaust device for venting the vacuum transfer chamber 31, in the case of a cryogenic pump that causes gas molecules to condense and adsorb at extremely low temperatures, the "thermally advantageous state" can also be that the arm 302 faces the exhaust port where the cryogenic pump is installed. In this case, the cooling unit 600 can be omitted.

[0148] Alternatively, when the fork 301 is stopped after it has been brought to a thermally advantageous state, the fork 301 may not stop moving immediately. For example, it may be configured such that if the threshold Y1 (e.g., X2 = Y1) is exceeded but the threshold Y2 is not exceeded, the fork 301 stops moving after all processing of the currently processed batch of substrates is completed; if the threshold Y2 is exceeded but the threshold Y3 is not exceeded, the fork 301 stops moving without loading unprocessed wafers W after they are removed from the processing station 11; and if the threshold Y3 is exceeded, the fork 301 stops moving immediately.

[0149] <Examples of variations of the conveyor arm>

[0150] Figure 6 This is a longitudinal cross-sectional view schematically illustrating another example of the structure of the wafer transport mechanism 32.

[0151] Figure 6 wafer transport mechanism 32 and Figure 2 Unlike the wafer transport mechanism 32, the cooling target area R1 is equipped with a fan 701 that supplies cooling air to the drive mechanism 401, the cooling target area R2 is equipped with a fan 702 that supplies cooling air to the drive mechanism 402, and the cooling target area R3 is equipped with a fan 703 that supplies cooling air to the drive mechanism 403.

[0152] The fans 701-703 can stir the air around the drive mechanisms 401-403, thereby improving the heat exchange efficiency between the compressed air supplied from the distribution pipes 511-513 and the drive mechanisms 401-403. Furthermore, the fans 701-703 can expel the air around the drive mechanisms 401-403 that has become hot due to heat exchange. Therefore, by providing the fans 701-703, the decrease in the movement accuracy of the fork 301, i.e., the decrease in the transport accuracy of the wafer transport mechanism 32 when transporting the wafer W, can be further suppressed.

[0153] Furthermore, in the above examples, the technology disclosed herein is applied to the vacuum conveying device 30, but it can also be applied to the atmospheric pressure conveying device 20.

[0154] All points in the embodiments disclosed herein should be considered illustrative rather than restrictive. The above embodiments may be omitted, substituted, or modified in various ways without departing from the appended claims and their spirit.

[0155] Explanation of reference numerals in the attached figures

[0156] 20: Atmospheric pressure conveying device; 23a: Conveying arm; 30: Vacuum conveying device; 32a: Conveying arm; 51: Control unit; 301: Fork; 302: Arm; 500: Cooling mechanism; 501: Compressed gas source; 551: Temperature sensor; 552: Temperature sensor; 553: Temperature sensor; Pn: Thermal index; Rn: Cooling target area; To: Reference temperature; Tn: Temperature; W: Wafer; αn: Influence degree; ΔTn: Change amount.

Claims

1. A substrate conveying apparatus for conveying substrates, the substrate conveying apparatus comprising: A conveying arm having a substrate support for supporting a substrate and an arm connected to the substrate support for moving the substrate support. A cooling mechanism that distributes cooling fluid from a fluid supply source to each of the multiple cooling target areas of the arm; The measuring unit measures the temperature of each of the cooled object areas; and Control Department in, The control unit calculates thermal parameters for each of the cooling target areas based on the change in temperature of the cooling target area relative to a reference temperature measured by the measuring unit, and the influence of the temperature of the cooling target area on the movement accuracy of the substrate support. The control unit determines the distribution ratio of cooling fluid from the fluid supply source by the cooling mechanism based on the thermal index.

2. The substrate conveying device according to claim 1, characterized in that, The conveying arm is a multi-joint arm. The conveying arm has a drive mechanism for driving relative rotation between the portions connected via the joint axes of the multi-joint arm. The drive mechanism is included in each of the aforementioned cooling target areas. The degree to which the temperature of the cooled target area affects the movement accuracy of the substrate support is determined based on the distance from the joint axis driven by the drive mechanism included in the cooled target area to the substrate support.

3. The substrate conveying device according to claim 1 or 2, characterized in that, The control unit determines the distribution ratio to make the thermal index equal across the cooling target areas.

4. The substrate conveying device according to claim 1 or 2, characterized in that, If the temperature measured by the measuring unit in all of the cooling target areas is lower than the threshold determined based on the allowable temperature of the cooling target area, the cooling mechanism distributes the cooling fluid from the fluid supply source according to a distribution ratio determined based on the thermal index. If the temperature measured by the measuring unit is higher than a threshold in only a portion of the area to be cooled, the cooling mechanism preferentially supplies cooling fluid from the fluid supply source to that portion of the area to be cooled.

5. The substrate conveying device according to claim 4, characterized in that, If the temperature measured by the measuring unit in at least one of the plurality of cooling target areas is higher than another threshold greater than the threshold, the control unit causes the moving speed of the substrate support to be lower than the normal speed, which is the speed at which the temperature measured by the measuring unit is lower than the threshold.

6. The substrate conveying device according to claim 4, characterized in that, If the temperature measured by the measuring unit in at least one of the plurality of cooling target areas is higher than another threshold greater than the threshold, the control unit causes the substrate support to stop for a predetermined time after each series of actions.

7. The substrate conveying device according to claim 5, characterized in that, If the temperature measured by the measuring unit in at least one of the plurality of cooling target areas is higher than another threshold greater than the threshold, the control unit makes the moving speed of the substrate support at the normal speed when the substrate support is supporting a substrate with a temperature higher than the specified temperature or when the substrate support enters or exits a transport destination with an internal temperature higher than the specified temperature; otherwise, the moving speed of the substrate support is lower than the normal speed.

8. The substrate conveying device according to claim 4, characterized in that, If the temperature measured by the measuring unit in at least one of the plurality of cooling target areas is higher than another threshold greater than the threshold value, the control unit stops the movement of the substrate support after placing the substrate support in a thermally advantageous state. The conveying arm is a multi-joint arm. The thermally advantageous state is when the articulated arm is folded and the substrate support is removed from the substrate's transport destination or transport source.

9. The substrate conveying device according to claim 4, characterized in that, If the temperature measured by the measuring unit in at least one of the plurality of cooling target areas is higher than another threshold greater than the threshold value, the control unit stops the movement of the substrate support after placing the substrate support in a thermally advantageous state. The substrate conveying device also includes a cooling section cooled by a cooling medium. The thermally advantageous state is when the arm faces the cooling medium.

10. The substrate conveying device according to claim 1 or 2, characterized in that, The conveying arm is a multi-joint arm. The conveying arm has a drive mechanism for driving the flexion and extension of the multi-joint arm. The conveying arm also includes a fan that supplies cooling medium to the drive mechanism.

11. A method for cooling an arm, said arm being the arm of a substrate conveying device for conveying substrates. The substrate conveying device includes a conveying arm, which has a substrate support portion for supporting the substrate and an arm connected to the substrate support portion for moving the substrate support portion. The cooling method for the arm includes the following steps: The temperature of each of the multiple cooling target areas in the arm is measured; For each of the cooling target areas, thermal parameters are calculated based on the measured temperature change of the cooling target area relative to the reference temperature and the influence of the temperature of the cooling target area on the conveying accuracy of the substrate support. The distribution ratio of cooling fluid from the fluid supply source to each of the plurality of cooling target areas is determined based on the thermal index; and Cooling fluid from the fluid supply source is supplied to each of the plurality of cooling target areas according to the determined allocation ratio.

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