Substrate transport system and substrate positioning method

Abstract

To improve throughput when conveying at least two substrates.SOLUTION: A substrate conveyance system includes: conveyance means which has a holding member that collectively holds at least two substrates by arranging them in the horizontal direction and conveys each held substrate to the conveyance destination from the conveyance source; a plurality of placement tables which are provided on the conveyance destination and on which each substrate held by the holding member is placed at the conveyance destination; a support member which is provided on each placement table, can move in the vertical direction relatively to each placement table, supports each substrate once while each substrate is placed on each placement table from the holding member, and separates each substrate from the holding member; and a plurality of pieces of movement means which moves each support member independently in the horizontal direction. The position adjustment of each substrate to each placement table is performed by the first substrate movement which moves each substrate held by the holding member on each placement table by the conveyance means, and the second substrate movement which moves each substrate supported by each support member on each placement table by the movement means.SELECTED DRAWING: Figure 2J

Description

Technical Field

[0001] The present disclosure relates to a substrate transfer system and a substrate position adjustment method.

Background Art

[0002] When performing plasma treatment on a wafer, for example, it is necessary to accurately place the wafer at a predetermined position in a process chamber. Therefore, various wafer alignment methods have been proposed conventionally. For example, Patent Document 1 discloses an apparatus including a transfer arm for transferring a wafer, a mounting table on which the wafer is placed, a substrate transfer device for transferring the wafer from the transfer arm to the mounting table, and a substrate position detection device for detecting the horizontal position of the wafer during wafer transfer. In the apparatus described in Patent Document 1, the substrate transfer device has a plurality of pins for supporting the wafer and driving means for driving the pins in the horizontal directions (X direction and Y direction). Further, the substrate position detection device has a plurality of imaging means for imaging the peripheral portion of the wafer. And in the apparatus described in Patent Document 1, when the substrate transfer device that has received the wafer from the transfer arm places the wafer on the mounting table, based on the imaging results by each imaging means, the pins are driven horizontally for each wafer, thereby correcting the horizontal position deviation of the wafer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The technology according to the present disclosure improves the throughput when transferring at least two substrates.

Means for Solving the Problems

[0005] One aspect of the technology described herein includes a holding member that holds at least two substrates side by side horizontally, a transport means for transporting each of the substrates held by the holding member from a transport source to a transport destination, a plurality of mounting tables provided at the transport destination on which each of the substrates held by the holding member is placed, a support member provided on each of the mounting tables and movable vertically relative to each of the mounting tables, which temporarily supports each of the substrates as they are being placed from the holding member onto each of the mounting tables to separate each of the substrates from the holding member, and a plurality of moving means for independently moving each of the support members horizontally, wherein the position adjustment of each of the substrates with respect to each of the mounting tables is performed by a first substrate movement, in which each of the substrates held by the holding member on each of the mounting tables is moved by the transport means, and a second substrate movement, in which each of the substrates supported by each of the support members on each of the mounting tables is moved by the moving means. [Effects of the Invention]

[0006] According to this disclosure, it is possible to improve throughput when transporting at least two substrates. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic top view illustrating an example of the configuration of a substrate transport system as a first embodiment of the technology relating to this disclosure. [Figure 2A] Figure 1 is a three-view diagram showing an example of the operating state of the substrate transport system. [Figure 2B] Figure 1 is a three-view diagram showing an example of the operating state of the substrate transport system. [Figure 2C] Figure 1 is a three-view diagram showing an example of the operating state of the substrate transport system. [Figure 2D] Figure 1 is a three-view diagram showing an example of the operating state of the substrate transport system. [Figure 2E] Figure 1 is a three-view diagram showing an example of the operating state of the substrate transport system. [Figure 2F]Figure 1 is a three-view diagram showing an example of the operating state of the substrate transport system. [Figure 2G] Figure 1 is a three-view diagram showing an example of the operating state of the substrate transport system. [Figure 2H] Figure 1 is a three-view diagram showing an example of the operating state of the substrate transport system. [Figure 2I] Figure 1 is a three-view diagram showing an example of the operating state of the substrate transport system. [Figure 2J] Figure 1 is a three-view diagram showing an example of the operating state of the substrate transport system. [Figure 3] This is a schematic top view illustrating an example of the configuration of a substrate transport system as a second embodiment of the technology relating to this disclosure. [Modes for carrying out the invention]

[0008] In the technology described in Patent Document 1 above, the pins need to be driven in both the X and Y directions, which complicates the structure of the pin driving mechanism and increases costs. Therefore, it has been proposed to eliminate the need to move the wafer with pins by using a transport arm for wafer alignment. Furthermore, it has been proposed that the transport arm transport multiple wafers to improve wafer transport and processing efficiency.

[0009] However, when a transport arm transports multiple wafers, if the transport arm aligns the wafers, it is necessary to move the transport arm in the X and Y directions each time the wafers are aligned. Therefore, the throughput of aligning all wafers may deteriorate.

[0010] Hereinafter, an embodiment of the technology relating to this disclosure will be described with reference to the drawings. However, the configuration described in the following embodiment is merely illustrative and does not limit the invention to this configuration. For example, each part and means included in this configuration can be replaced with any other part that can perform a similar function. In addition, any additional components may be included.

[0011] <First Embodiment> The first embodiment will be described below with reference to Figures 1 to 2J. In each figure, three mutually orthogonal directions are assumed, with two mutually orthogonal directions in the horizontal direction being called the "X direction" and the "Y direction," respectively, and the vertical direction being called the "Z direction." The direction in which the arrows in each direction point is called the "positive side (or +)," and the opposite direction is called the "negative side (or -)." Figure 1 is a schematic top view schematically showing an example of the configuration of a substrate transport system as the first embodiment of the technology according to this disclosure. The substrate transport system 1 shown in Figure 1 is a system that transports semiconductor wafers (hereinafter referred to as "wafer W") with a diameter of, for example, 300 mm to 450 mm (φ300 mm to φ450 mm) as substrates. The substrate transport system 1 comprises a load port 11, a loader module (loader chamber) 12, a load lock module (load lock chamber) 13, a transfer module (substrate transport chamber) 14, and a process module (substrate processing chamber) 15.

[0012] A hoop (not shown), which is a container for holding multiple wafers W, is placed on the load port 11. In this embodiment, four load ports 11 are arranged along the Y direction, but the number of load ports 11 is not limited to four. Loader modules 12 are arranged adjacent to these four load ports 11 on the negative X side. The inside of the loader module 12 is always at atmospheric pressure. A transport robot (not shown) for loading and unloading wafers W to and from the hoop is also arranged inside the loader module 12. In this way, the loader module 12 transports wafers W between the hoop placed on the load port 11 and the load lock module 13. Two load lock modules 13 are arranged adjacent to the negative X side of the load module 12. The two load lock modules 13 are arranged along the Y direction. Each load lock module 13 is configured so that its interior can be selectively switched between a vacuum atmosphere and an atmospheric pressure atmosphere. Furthermore, the interior of each load lock module 13 is maintained under atmospheric pressure when communicating with the loader module 12, and under a vacuum when communicating with the transfer module 14. Each load lock module 13 serves as an intermediate transport chamber for transporting wafers W between the loader module 12 and the transfer module 14.

[0013] A transfer module 14 is positioned adjacent to the negative X-direction side of the two load lock modules 13. The interior of the transfer module 14 is always maintained at a predetermined vacuum level. A transfer robot 16 is also positioned in the transfer module 14 as a means of transporting wafers W. The transfer robot 16 has a multi-joint arm 161 and a fork (pick) 162 attached to the tip of the multi-joint arm 161, which is roughly U-shaped (long) in plan view. The fork 162 is a holding member that holds at least two wafers W in a row in the horizontal direction. In this embodiment, the number of wafers W that the fork 162 can hold is a maximum of four (see, for example, Figure 2A), but is not limited to this. The fork 162 can also stably hold each wafer W by, for example, static electricity. The transfer robot 16 can transport each wafer W from the transport source to the transport destination by extending and retracting the multi-joint arm 161 while each wafer W is held by the fork 162. This transport includes transport between each process module 15 and transport between the process module 15 and the load lock module 13.

[0014] In addition, the substrate transfer system 1 includes a sensor pair 23 as detection means for detecting the position of each wafer W with respect to the fork 162 during this transfer. The sensor pair 23 is arranged inside the transfer module 14 so as to face the front of each process module 15, and has a left sensor 23L on the left side facing the process module 15 and a right sensor 23R on the right side facing the process module 15. In each sensor pair 23, the right sensor 23R and the left sensor 23L are separated from each other at an interval smaller than the diameter of the wafer W, and both are arranged so as to face the back surface of the wafer W transported by the transfer robot 16. Each of the right sensor 23R and the left sensor 23L detects the passage of the outer edge (hereinafter simply referred to as "edge") of the wafer W above. Further, the substrate transfer system 1 includes a control unit 17 that controls the operation of each component of the substrate transfer system 1 (such as the transfer robot 16, etc.). The control unit 17 has a CPU, a memory, and the like. The CPU executes a substrate position adjustment method described later according to a program stored in the memory or the like. The control unit 17 calculates the position of each wafer W with respect to the fork 162 when the edge of the wafer W passes above the right sensor 23R or the left sensor 23L, specifically, the center of gravity position of each wafer W from the encoder values of the three motors of the transfer robot 16. Note that the sensor position for detecting the position of each wafer W is not limited to that shown in FIG. 1.

[0015] Six process modules 15 are arranged adjacent to the transfer module 14, each connected by a gate valve 18. In this embodiment, three of the six process modules 15 are arranged along the X direction on the positive Y direction side of the transfer module 14, and the remaining three process modules 15 are arranged along the X direction on the negative Y direction side of the transfer module 14. The gate valve 18 controls the communication between the transfer module 14 and the process modules 15. The interior of each process module 15 is kept under vacuum at a predetermined level. Multiple mounting tables 19 are also arranged inside each process module 15. Each wafer W held by the fork 162 is placed one by one on a mounting table 19. The wafers W placed on the mounting tables 19 are then subjected to a predetermined plasma treatment, such as plasma etching. In this embodiment, four mounting tables 19 are arranged inside each process module 15. These four mounting tables 19 are arranged two each along the X direction and the Y direction. The number and arrangement of the mounting platforms 19 are not limited to those shown in Figure 1.

[0016] As shown in Figures 2A to 2J, each mounting base 19 is provided with a lifter 24 that is movable vertically relative to the mounting base 19, i.e., in the Z direction. The lifter 24 is a support member that temporarily lifts and supports each wafer W from below as it is being placed from the fork 162 onto each mounting base 19. This support allows each wafer W to be separated from the fork 162. Each lifter 24 has three pins 25 that protrude upward, i.e., toward the positive Z direction, and are spaced apart from each other horizontally. These three pins 25 allow the wafer W to be supported at three points. This allows the wafer W to be kept in a stable horizontal position. The number of pins 25 on the lifter 24 does not need to be more than three. The lifter 24 is also connected to a drive source (not shown), such as a motor or air cylinder, and can be moved vertically by the drive source.

[0017] Each lifter 24 is connected with a piezo actuator 26 as moving means for independently moving the lifter 24 in the horizontal direction. Note that the direction in which each piezo actuator 26 moves the lifter 24 varies depending on the lifter 24 to which the piezo actuator 26 is connected, but is either one of the X direction and the Y direction. The piezo actuator 26 is used for position adjustment (fine adjustment) when the wafer W is placed on the mounting table 19. The piezo actuator 26 is relatively small in size depending on its type, is easy to connect to the lifter 24, and has high resolution in position adjustment. Note that, in this embodiment, the piezo actuator 26 is used as the moving means for independently moving the lifter 24 in the horizontal direction, but the present invention is not limited thereto, and for example, a servo motor or the like can also be used.

[0018] Next, a substrate position adjustment method will be described with reference to FIGS. 2A to 2J. FIGS. 2A to 2J are three views sequentially showing an example of the operating state of the substrate transfer system shown in FIG. 1. (a) of these drawings is a top view, and (b) and (c) are side views, respectively. The substrate position adjustment method includes a position adjustment step of performing position adjustment of each wafer W with respect to each mounting table 19 using the substrate transfer system 1. Here, one of the six process modules 15 will be typically described as the transfer destination where the position adjustment step is performed.

[0019] As shown in Figure 2A, within the process module 15, two wafers W are held at the tip end (positive Y-direction side) of the fork 162, and two wafers W are held at the base end (negative Y-direction side). In other words, within the process module 15, two wafers W are held on the fork 162 along the X-direction and the Y-direction. Hereinafter, of these four wafers W, the wafer W located on the most positive side in the X-direction and Y-direction will be referred to as "wafer W1", the wafer W located on the negative X-direction side of wafer W1 will be referred to as "wafer W2", the wafer W located on the negative Y-direction side of wafer W1 will be referred to as "wafer W3", and the wafer W located on the negative X-direction side of wafer W3 will be referred to as "wafer W4". Furthermore, the mounting platform 19 on which wafer W1 is placed is called "mounting platform 191," the mounting platform 19 on which wafer W2 is placed is called "mounting platform 192," the mounting platform 19 on which wafer W3 is placed is called "mounting platform 193," and the mounting platform 19 on which wafer W4 is placed is called "mounting platform 194." Also, the lifter 24 that raises and lowers wafer W1 is called "lifter 241," the lifter 24 that raises and lowers wafer W2 is called "lifter 242," the lifter 24 that raises and lowers wafer W3 is called "lifter 243," and the lifter 24 that raises and lowers wafer W4 is called "lifter 244." Furthermore, the piezo actuator 26 that moves the lifter 241 horizontally is called "piezo actuator 261", the piezo actuator 26 that moves the lifter 242 horizontally is called "piezo actuator 262", the piezo actuator 26 that moves the lifter 243 horizontally is called "piezo actuator 263", and the piezo actuator 26 that moves the lifter 244 horizontally is called "piezo actuator 264". Also, the direction in which piezo actuator 261 moves the lifter 241 is the Y direction, the direction in which piezo actuator 262 moves the lifter 242 is the X direction, the direction in which piezo actuator 263 moves the lifter 243 is the Y direction, and the direction in which piezo actuator 264 moves the lifter 244 is the X direction.

[0020] As shown in Figure 2A, the fork 162 enters the process module 15 and stops while holding wafers W1 to W4. At this time, wafer W1 is located on the mounting table 191, wafer W2 is located on the mounting table 192, wafer W3 is located on the mounting table 193, and wafer W4 is located on the mounting table 194. Furthermore, wafers W1 to W4 have not yet been aligned. Specifically, wafer W1 has a misalignment of "+ΔX1" in the X direction and a misalignment of "+ΔY1" in the Y direction. Wafer W2 has a misalignment of "+ΔX2" in the X direction and a misalignment of "+ΔY2" in the Y direction. Wafer W3 has a misalignment of "+ΔX3" in the X direction and a misalignment of "+ΔY3" in the Y direction. The wafer W4 is in a state where it has a positional displacement of "+ΔX4" in the X direction and a positional displacement of "+ΔY4" in the Y direction. The amount of each positional displacement (displacement) is calculated by the control unit 17 based on the detection results detected by the sensor pair 23. Therefore, in this embodiment, the control unit 17 functions as a calculation means. The position adjustment process starts from this state.

[0021] First, starting from the state shown in Figure 2A, the X-direction misalignment of wafer W1 (one of the wafers W) located at the tip side is eliminated. As shown in Figure 2B, the fork 162 (transport robot 16) is moved by "+ΔX1" to the negative X-direction (first substrate movement). This first substrate movement eliminates the X-direction misalignment of wafer W1, that is, cancels it out (no X-direction misalignment), and the X-direction position adjustment of wafer W1 is completed. At this time, wafer W2 has a new X-direction misalignment amount "+ΔX1" added to the original X-direction misalignment amount "+ΔX2" due to the first substrate movement of wafer W1. As a result, the total X-direction misalignment amount of wafer W2 (total misalignment amount) becomes "+ΔX2-(+ΔX1)". Similarly, for wafer W3, the first substrate movement of wafer W1 adds a new displacement amount "(+ΔX1)" to the original displacement amount "+ΔX3" in the X direction on the negative side of the X direction. As a result, the total displacement amount of wafer W3 in the X direction becomes "+ΔX3-(+ΔX1)". Also, for wafer W4, the first substrate movement of wafer W1 adds a new displacement amount "+ΔX1" to the original displacement amount "+ΔX4" in the X direction on the negative side of the X direction. As a result, the total displacement amount of wafer W4 in the X direction becomes "+ΔX4-(+ΔX1)". These calculations of each total displacement amount are also performed in the control unit 17 (the same applies to the total displacement amounts below, i.e., the amount of movement in each substrate movement).

[0022] Next, from the state shown in Figure 2B, the Y-direction misalignment of wafer W2 (the other wafer W) is corrected. As shown in Figure 2C, the fork 162 is moved to the negative Y-direction by "+ΔY2" (first substrate movement). This first substrate movement corrects the Y-direction misalignment of wafer W2 (no Y-direction misalignment), and the Y-direction position adjustment with respect to wafer W2 is completed. At this time, for wafer W1, the first substrate movement of wafer W2 adds a new misalignment amount "+ΔY2" to the original Y-direction misalignment amount "+ΔY1" in the negative Y-direction. Similarly, for wafer W3, the first substrate movement of wafer W2 adds a new misalignment amount "+ΔY2" to the original Y-direction misalignment amount "+ΔY3" in the negative Y-direction. As a result, the total Y-direction misalignment amount of wafer W3 becomes "+ΔY3-(+ΔY2)". Furthermore, as wafer W2 moves forward for the first time, a new displacement amount "(+ΔY2)" is added to the original displacement amount "+ΔY4" in the Y direction for wafer W4. As a result, the total displacement amount of wafer W4 in the Y direction becomes "+ΔY4-(+ΔY2)".

[0023] Next, as shown in Figure 2D, lifter 241 is moved to the positive Z-direction (upward), and lifter 242 is also moved to the positive Z-direction. At this time, wafer W1 rises while its X-direction misalignment is eliminated and moves away from fork 162. Wafer W2 rises while its Y-direction misalignment is eliminated and moves away from fork 162.

[0024] Next, from the state shown in Figure 2D, the X-direction displacement of wafer W3 (one of the wafers W) located on the base end side is corrected. As shown in Figure 2E, the fork 162 is moved to the negative X-direction by the aforementioned total displacement amount "+ΔX3-(+ΔX1)" (first substrate movement). This first substrate movement corrects the X-direction displacement of wafer W3 (no X-direction displacement), and the X-direction position adjustment for wafer W3 is completed. At this time, wafer W4 has a new displacement amount "+ΔX3-(+ΔX1)" added to the previous (original) X-direction displacement amount "+ΔX4-(+ΔX1)" due to the first substrate movement of wafer W3. As a result, the total X-direction displacement amount of wafer W4 becomes "+ΔX4-(+ΔX1)-(+ΔX3-(+ΔX1))".

[0025] Next, from the state shown in Figure 2E, the Y-direction displacement of wafer W4 (the other wafer W) is corrected. As shown in Figure 2F, the fork 162 is moved to the negative Y-direction by the total displacement amount "+ΔY4-(+ΔY2)" mentioned above (first substrate movement). This first substrate movement corrects the Y-direction displacement of wafer W4 (no Y-direction displacement), and the Y-direction position adjustment of wafer W4 is completed. At this time, wafer W3 has a new displacement amount "+ΔY4-(+ΔY2)" added to the previous Y-direction displacement amount "+ΔY3-(+ΔY2)" due to the first substrate movement of wafer W4. As a result, the total Y-direction displacement amount of wafer W3 becomes "+ΔY3-(+ΔY2)-(+ΔY4-(+ΔY2))".

[0026] Next, as shown in Figure 2G, lifter 243 is moved to the positive Z-direction (upward), and lifter 244 is also moved to the positive Z-direction. At this time, wafer W3 rises while its X-direction misalignment is eliminated and moves away from fork 162. Wafer W4 rises while its Y-direction misalignment is eliminated and moves away from fork 162.

[0027] As mentioned above, wafers W1 to W4 are all separated from the fork 162. From this state, as shown in Figure 2H, the fork 162 is moved to the negative side in the Y direction to retract it from the process module 15.

[0028] Next, from the state shown in Figure 2H, the misalignment of wafer W1 in the Y direction, the misalignment of wafer W2 in the X direction, the misalignment of wafer W3 in the Y direction, and the misalignment of wafer W4 in the X direction are corrected. As mentioned above, the misalignment of wafer W1 in the X direction, the misalignment of wafer W2 in the Y direction, the misalignment of wafer W3 in the X direction, and the misalignment of wafer W4 in the Y direction have all already been corrected. As shown in Figure 2I, the piezo actuator 261261 moves the lifter 241 to the negative side of the Y direction by "+ΔY1" (second substrate movement). This second substrate movement corrects the misalignment of wafer W1 in the Y direction (no misalignment in the Y direction), and the Y-direction position adjustment with respect to wafer W1 is completed. Furthermore, the piezo actuator 262 moves the lifter 242 to the negative side in the X direction by the aforementioned total misalignment amount "+ΔX2-(+ΔX1)" (second substrate movement). This second substrate movement eliminates the X-direction misalignment of wafer W2 (no X-direction misalignment), completing the X-direction position adjustment of wafer W2. Furthermore, the piezo actuator 263 moves the lifter 243 to the negative side in the Y direction by the aforementioned total misalignment amount "+ΔY3-(+ΔY2)-(+ΔY4-(+ΔY2))" (second substrate movement). This second substrate movement eliminates the Y-direction misalignment of wafer W3 (no Y-direction misalignment), completing the Y-direction position adjustment of wafer W3. Furthermore, the piezo actuator 264 moves the lifter 244 to the negative side in the X direction by the total displacement amount "+ΔX4-(+ΔX1)-(+ΔX3-(+ΔX1))" mentioned above (second substrate movement). This second substrate movement eliminates the X-direction misalignment of the wafer W4 (no X-direction misalignment), and the X-direction position adjustment of the wafer W4 is completed.

[0029] Next, as shown in Figure 2J, lifters 241 to 244 are moved to the negative side (downward) in the Z direction. As a result, wafer W1 descends while its positional misalignment in the X and Y directions is eliminated, and is placed on the mounting table 191 in an accurately positioned state. Similarly, wafer W2 descends while its positional misalignment in the X and Y directions is eliminated, and is placed on the mounting table 192 in an accurately positioned state. Wafer W3 also descends while its positional misalignment in the X and Y directions is eliminated, and is placed on the mounting table 193 in an accurately positioned state. Wafer W4 also descends while its positional misalignment in the X and Y directions is eliminated, and is placed on the mounting table 194 in an accurately positioned state.

[0030] As described above, in the position adjustment process, the position of wafer W1 is adjusted by a first substrate movement (see Figure 2B) in which wafer W1, held on the fork 162 on the mounting table 191, is moved in the X direction by the transport robot 16, and a second substrate movement (see Figure 2I) in which wafer W1, supported on the lifter 241 on the mounting table 191, is moved in the Y direction by the piezo actuator 261. In addition, the position of wafer W2 is adjusted by a first substrate movement (see Figure 2C) in which wafer W2, held on the fork 162 on the mounting table 192, is moved in the Y direction by the transport robot 16, and a second substrate movement (see Figure 2I) in which wafer W2, supported on the lifter 242 on the mounting table 192, is moved in the X direction by the piezo actuator 262. Furthermore, to adjust the position of wafer W3, a first substrate movement (see Figure 2E) is performed, in which wafer W3, held by forks 162 on the mounting table 193, is moved in the X direction by the transport robot 16, and a second substrate movement (see Figure 2I) is performed, in which wafer W3, supported by lifter 243 on the mounting table 193, is moved in the Y direction by piezo actuator 263. Furthermore, to adjust the position of wafer W4, a first substrate movement (see Figure 2F) is performed, in which wafer W4, held by forks 162 on the mounting table 194, is moved in the Y direction by the transport robot 16, and a second substrate movement (see Figure 2I) is performed, in which wafer W4, supported by lifter 244 on the mounting table 194, is moved in the X direction by piezo actuator 264.

[0031] Incidentally, conventionally, as mentioned above, when a transport arm transports multiple wafers, if the transport arm aligns the wafers, it is necessary to move the transport arm in the X and Y directions each time the wafer is aligned. As a result, there was a risk that the throughput until all wafers were aligned would deteriorate.

[0032] In contrast, the substrate transport system 1 (substrate position adjustment method) divides the X-direction position adjustment and Y-direction position adjustment of each wafer W between the transport robot 16 and the piezo actuator 26. This eliminates the need to move the transport arm in the X and Y directions during the alignment of each wafer, thereby improving the throughput of wafer alignment from W1 to W4. Furthermore, since the piezo actuator 26 only needs to be responsible for either the X-direction or Y-direction position adjustment, the positioning configuration can be simplified compared to, for example, a configuration where the piezo actuator 26 is responsible for both the X and Y-direction position adjustments.

[0033] Furthermore, in the position adjustment process, the position adjustment of wafers W1 and W2 at the leading edge is performed before the position adjustment of wafers W3 and W4 at the base edge. Therefore, wafers W1 and W2 are separated from the fork 162 before wafers W3 and W4. Conversely, let's consider the case where wafers W3 and W4 are separated from the fork 162 before wafers W1 and W2. In this case, even if the fork 162 is to be retracted from the process module 15 due to various reasons such as an error, wafer W1 on the fork 162 may collide with the pin 25 of the lifter 243, and wafer W2 on the fork 162 may collide with the pin 25 of the lifter 244, potentially hindering its retraction. However, in the position adjustment process described above, wafers W1 and W2 are separated from the fork 162 before wafers W3 and W4, so the fork 162 can be retracted from the process module 15 quickly. Furthermore, if there is no possibility of retracting the fork 162 from the process module 15 during the alignment of each wafer, the positional adjustment for wafers W3 and W4 may be performed before the positional adjustment for wafers W1 and W2.

[0034] Furthermore, the operation to positions where the first substrate movement shown in Figure 2A has not been performed does not need to be performed, and the first substrate movement of wafer W1 in the X direction and the first substrate movement of wafer W2 in the Y direction may be performed at the same time (see Figures 2A, 2B, and 2C). Similarly, the first substrate movement of wafer W3 in the X direction and the first substrate movement of wafer W4 in the Y direction may be performed at the same time (see Figures 2E and 2F). In this case, the first substrate movement of wafers W1 to W2 and the first substrate movement of wafers W3 to W4 are performed at different times. This is because, since the transport robot 16 can adjust only one position each in the X and Y directions at a time, when the fork 162 is maintaining the positional relationship between wafers W1 to W4, wafers W1 to W2 and wafers W3 to W4 cannot perform the first substrate movement in the X direction and the first substrate movement in the Y direction at the same time. On the other hand, the second substrate movement of wafer W1 in the Y direction, the second substrate movement of wafer W2 in the X direction, the second substrate movement of wafer W3 in the Y direction, and the second substrate movement of wafer W4 in the X direction are performed at the same time (see Figure 2I). This is because each piezo actuator 26 is configured to operate independently, allowing the second substrate movement in the X direction and the second substrate movement in the Y direction to be performed at the same time. Furthermore, the simultaneous execution of the second substrate movement in the X direction and the second substrate movement in the Y direction contributes to improving the throughput of wafer alignment.

[0035] In this embodiment, the number of wafers W held by the fork 162 is even. In the position adjustment process in this case, the position of all wafers W can be adjusted by repeating the position adjustment by first substrate movement and second substrate movement for each pair of wafers W arranged along the X direction. After the state shown in Figure 2D, a second substrate movement of wafer W1 in the Y direction and a second substrate movement of wafer W2 in the X direction may be performed. In this case, the second substrate movement of wafer W1 in the Y direction and the second substrate movement of wafer W2 in the X direction in the state shown in Figure 2I are omitted.

[0036] <Second Embodiment> The second embodiment will now be described with reference to Figure 3, focusing on the differences from the previously described embodiment, and omitting explanations of similar matters. This embodiment is the same as the first embodiment except for the number of wafers held on the fork. Specifically, the number of wafers arranged on the fork was even in the first embodiment, but odd in this embodiment.

[0037] Figure 3 is a schematic top view illustrating an example of the configuration of a substrate transport system as a second embodiment of the technology according to this disclosure. As shown in Figure 3, within the process module 15, wafers W1 and W2 are arranged along the X direction on the tip side of the fork 162, and wafer W3 is arranged on the base side. The X coordinate of wafer W3 is an intermediate coordinate between the X coordinate of wafer W1 and the X coordinate of wafer W2. In the position adjustment step of this embodiment, the same position adjustment as for wafers W1 and W2 in the first embodiment can be used for adjusting the positions of wafers W1 and W2. Furthermore, the position adjustment of wafer W3 is performed by movement in the X and Y directions by the fork 162. This makes it possible to omit horizontal movement of wafer W3 while it is supported by the lifter 24.

[0038] As described above, in this embodiment, when performing the position adjustment process when the number of wafers W arranged on the fork 162 is odd, the position adjustment can be repeated for each of the two wafers W arranged along the X direction by moving the first substrate and moving the second substrate. Then, the position adjustment for the remaining wafer W is performed by movement by the fork 162. As a result, all wafers W can be placed on the mounting table 19 in an accurately positioned state. Note that the position adjustment for the remaining wafer W may also be performed by horizontal movement by the piezo actuator 26.

[0039] While preferred embodiments of this disclosure have been described above, this disclosure is not limited to the embodiments described above, and various modifications and changes are possible within the scope of its essence. [Explanation of symbols]

[0040] 1. Substrate transport system 16 Transport robots 162 Fork (pick) 19, 191, 192, 193, 194 Mounting platform 24, 241, 242, 243, 244 Lifters 26, 261, 262, 263, 264 Piezo actuators W, W1, W2, W3, W4 wafers

Claims

1. A conveying means having a holding member that holds at least two substrates side by side horizontally, and conveying each of the substrates held by the holding member from a conveying source to a conveying destination, A plurality of mounting tables are provided at the transport destination, on which each of the substrates held by the holding member is placed; A support member is provided on each of the aforementioned mounting bases, is movable vertically relative to each of the aforementioned mounting bases, and temporarily supports each of the aforementioned substrates as they are being placed from the holding member onto each of the mounting bases, thereby separating each of the substrates from the holding member. The system comprises a plurality of moving means for independently moving each of the aforementioned support members in the horizontal direction, A substrate transport system in which the position adjustment of each substrate with respect to each mounting table is performed by a first substrate movement, in which each substrate held by the holding member on each mounting table is moved by the transport means, and a second substrate movement, in which each substrate supported by the support member on each mounting table is moved by the transport means.

2. The substrate transport system according to claim 1, wherein the direction of movement in the first substrate transport and the direction of movement in the second substrate transport are orthogonal to each other.

3. The substrate transport system according to claim 2, wherein, of the two substrates, the direction of movement of one substrate in the first substrate transport and the direction of movement of the other substrate in the first substrate transport are mutually orthogonal, and the direction of movement of one substrate in the second substrate transport and the direction of movement of the other substrate in the second substrate transport are mutually orthogonal.

4. The substrate transport system according to claim 2, wherein the movement of the second substrate of one substrate and the movement of the second substrate of the other substrate are performed at the same timing.

5. Assuming mutually orthogonal X and Y directions, and defining the direction of movement of one substrate during the first substrate movement as the X direction, the direction of movement of the other substrate during the first substrate movement as the Y direction, the direction of movement of one substrate during the second substrate movement as the Y direction, and the direction of movement of the other substrate during the second substrate movement as the X direction, The position of the first substrate is adjusted in the X direction by the movement of the first substrate. The substrate transport system according to claim 2, wherein the position of the other substrate is adjusted in the Y direction by the movement of the first substrate of the other substrate.

6. The first substrate moves, and the new displacement in the Y direction is added to the original displacement in the Y direction. The total displacement, obtained by adding the new displacement to the Y direction displacement, is then canceled out by the movement of the second substrate, thereby adjusting the position in the Y direction. The substrate transport system according to claim 5, wherein the position of the other substrate is adjusted in the X direction by the movement of the first substrate, the new amount of displacement in the X direction of the first substrate being added to the original amount of displacement in the X direction, and the total amount of displacement obtained by adding the new amount of displacement to the amount of displacement in the X direction being canceled out by the movement of the second substrate.

7. The holding member is elongated, with two of the substrates held at its tip end and two of the substrates held at its base end. The substrate transport system according to claim 1, wherein when performing the position adjustment, the position adjustment for the two substrates on the leading edge side is performed before the position adjustment for the two substrates on the base end side.

8. The substrate transport system according to claim 1, wherein when performing the position adjustment when the number of substrates held by the holding member is even, the position adjustment by moving the first substrate and moving the second substrate is repeated for every two substrates.

9. The substrate transport system according to claim 1, wherein when the position adjustment is performed when the number of substrates held by the holding member is odd, the position adjustment is repeated for every two substrates by moving the first substrate and moving the second substrate, and the position adjustment for the remaining substrate is performed by moving it with the transport means.

10. During the transport of each substrate from the transport source to the transport destination, a detection means is provided to detect the position of each substrate relative to the holding member, The substrate transport system according to claim 1, further comprising: a calculation means for calculating the amount of movement of each substrate during the first substrate movement and the amount of movement of each substrate during the second substrate movement, based at least on the detection results of the detection means.

11. The substrate transport system according to claim 1, wherein the transport means has a piezo actuator.

12. The substrate transport system according to claim 1, wherein the support member places each substrate on each of the mounting tables after the position adjustment.

13. The substrate transport system according to claim 1, wherein the support member supports each of the substrates at at least three points.

14. A conveying means having a holding member that holds at least two substrates side by side horizontally, and conveying each of the substrates held by the holding member from a conveying source to a conveying destination, A plurality of mounting tables are provided at the transport destination, on which each of the substrates held by the holding member at the transport destination is placed, A support member is provided on each of the aforementioned mounting bases, is movable vertically relative to each of the aforementioned mounting bases, and temporarily supports each of the aforementioned substrates as they are being placed from the holding member onto each of the mounting bases, thereby separating each of the substrates from the holding member. A substrate transport system comprising a plurality of moving means for independently moving each of the aforementioned support members in the horizontal direction, The system includes a position adjustment step for adjusting the position of each substrate relative to each mounting base, A substrate position adjustment method comprising: a first substrate movement in which each substrate held by the holding member on each mounting table is moved by the transport means; and a second substrate movement in which each substrate supported by the support member on each mounting table is moved by the moving means.

15. The substrate position adjustment method according to claim 14, wherein the direction of movement in the first substrate movement and the direction of movement in the second substrate movement are orthogonal to each other.

16. The substrate position adjustment method according to claim 15, wherein, of the two substrates, the direction of movement of one substrate in the first substrate movement and the direction of movement of the other substrate in the first substrate movement are mutually orthogonal, and the direction of movement of one substrate in the second substrate movement and the direction of movement of the other substrate in the second substrate movement are mutually orthogonal.

17. The substrate position adjustment method according to claim 15, wherein the movement of the second substrate of one substrate and the movement of the second substrate of the other substrate are performed at the same timing.

18. Assuming mutually orthogonal X and Y directions, and defining the direction of movement of one substrate during the first substrate movement as the X direction, the direction of movement of the other substrate during the first substrate movement as the Y direction, the direction of movement of one substrate during the second substrate movement as the Y direction, and the direction of movement of the other substrate during the second substrate movement as the X direction, The position of the first substrate is adjusted in the X direction by the movement of the first substrate. The substrate position adjustment method according to claim 15, wherein the position of the other substrate is adjusted in the Y direction by the movement of the first substrate of the other substrate.

19. The first substrate moves, and the new displacement in the Y direction is added to the original displacement in the Y direction. The total displacement, obtained by adding the new displacement to the Y direction displacement, is then canceled out by the movement of the second substrate, thereby adjusting the position in the Y direction. The substrate position adjustment method according to claim 18, wherein the position of the other substrate is adjusted by the movement of the second substrate, where the new displacement in the X direction due to the movement of the first substrate is added to the original displacement in the X direction, and the total displacement obtained by adding the new displacement to the displacement in the X direction is canceled out by the movement of the second substrate.

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