Centering device, centering method, and substrate processing apparatus

Abstract

To match a center of a disc-shaped substrate mounted on a top face of a substrate support section to a center of the substrate support section with high throughput.SOLUTION: On a top face of a substrate support section, a substrate is enclosed by a first abutment member located at a first reference position, a second abutment member located at a second reference position and a third member located at a third reference position in a horizontal plane. The three abutment members are made gradually proximate to the substrate while keeping equal distances from a center of the substrate support section by repeating fine movements of the three abutment members. The abutment members are successively abutted to the substrate during the proximate movement and the substrate is horizontally moved toward the center of the substrate support section. As a result, at a time point in which the substrate is held by the three abutment members, a center of the substrate is matched to the center of the substrate support section, and centering processing is completed.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a centering technique for aligning the center of a disk-shaped substrate placed on the upper surface of a substrate support with the center of the substrate support, and to a substrate processing apparatus that processes the substrate using the centering technique, including bevel etching. [Background technology]

[0002] Substrate processing apparatuses are known that rotate substrates such as semiconductor wafers and supply processing liquids to the peripheral edges of the substrates to perform chemical processing, cleaning, and other processes. For example, in the apparatus described in Patent Document 1, the substrate is supported from below by a spin chuck (an example of a "substrate support unit" in the present invention) and held by suction. If the center of the spin chuck and the center of the substrate are misaligned, processing quality will be reduced. Therefore, in the above apparatus, a so-called centering process is performed to reduce the eccentricity of the substrate relative to the spin chuck before processing the substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-149423 Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional device described above, the centering process is performed in two stages. First, the eccentricity of the substrate relative to the spin chuck is measured. Next, the substrate on the spin chuck is pushed horizontally with a pusher, moving the center of the substrate toward the center of the spin chuck (the axis of rotation). Therefore, there is still room for improvement in terms of throughput.

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a centering technique that can align the center of a disk-shaped substrate placed on the upper surface of a substrate support part with the center of the substrate support part with excellent throughput, and a substrate processing apparatus that uses this centering technique. [Means for solving the problem]

[0006] A first aspect of the present invention is a centering device that positions a disk-shaped substrate placed on the upper surface of a substrate support part by moving the substrate horizontally on the upper surface of the substrate support part so that the center of the substrate coincides with the center of the substrate support part, the centering device comprising: a first abutting member that is movable in a first horizontal direction from a first reference position toward the center of the substrate support part in a horizontal plane, the first abutting member being a reference distance longer than the radius of the substrate from the center of the substrate support part; a second abutting member that is movable in a second horizontal direction different from the direction from a second reference position toward the center of the substrate support part and approaching the substrate on the opposite side of the first abutting member with respect to the center of the substrate support part in the horizontal plane, the second abutting member being deviated from an imaginary line extending from the center of the substrate support part in the first horizontal direction and being a reference distance from the center of the substrate support part; a third abutment member that is movable in a third horizontal direction different from the direction from the third reference position toward the center of the substrate support portion and that approaches the substrate, the third abutment member being on the opposite side of the second abutment member with respect to the virtual line and a reference distance away from the center of the substrate support portion; a movement mechanism that moves the first abutment member, the second abutment member, and the third abutment member in the first horizontal direction, the second horizontal direction, and the third horizontal direction, respectively; and a control unit that controls the movement mechanism, wherein the control unit repeats minute movements of moving the first abutment member, the second abutment member, and the third abutment member by a first movement amount, a second movement amount, and a third movement amount, respectively, so that the distances of the first abutment member, the second abutment member, and the third abutment member from the center of the substrate support portion are kept constant, and stops the minute movements when it is confirmed that the first abutment member, the second abutment member, and the third abutment member have sandwiched the substrate. and finish the centering process for the board. It is characterized by the following.

[0007] A second aspect of the present invention is a centering method for aligning the center of a disk-shaped substrate with the center of a substrate support part, the method comprising the steps of: positioning a first abutment member at a first reference position in a horizontal plane that is a reference distance away from the center of the substrate support part that is longer than a radius of the substrate; positioning a second abutment member at a second reference position on the opposite side of the first abutment member with respect to the center of the substrate support part, that is off an imaginary line extending from the first reference position through the center of the substrate support part and that is the reference distance away from the center of the substrate support part; and positioning a third abutment member at a third reference position on the opposite side of the first abutment member with respect to the center of the substrate support part and that is the reference distance away from the center of the substrate support part, that is the opposite side of the second abutment member with respect to the imaginary line and a step of repeating micro-movements, while the substrate is placed on the upper surface of the substrate support section so as to be freely movable horizontally, moving the first abutment member in a first horizontal direction from a first reference position toward the center of the substrate support section, moving the second abutment member by a second movement amount in a second horizontal direction different from the direction from the second reference position toward the center of the substrate support section and approaching the substrate, so that the distances from the center of the substrate support section of the first abutment member, the second abutment member, and the third abutment member are kept constant; and stopping the micro-movements when it is confirmed during the repetition of the micro-movements that the substrate is sandwiched between the first abutment member, the second abutment member, and the third abutment member. and finish the centering process for the board. The method is characterized by comprising the steps of:

[0008] Furthermore, a third aspect of the present invention is characterized by comprising a substrate support part having an upper surface that supports a substrate in a horizontal position; the above-mentioned centering device; a suction part that evacuates the space between the substrate positioned by the centering device and the substrate support part to adsorb and hold the substrate on the substrate support part; a rotation drive part that rotates the substrate support part that adsorbs and holds the substrate around the center of the substrate support part; and a processing liquid supply mechanism that supplies processing liquid to the peripheral edge of the substrate that is rotated around the center of the substrate support part integrally with the substrate support part.

[0009] In the invention configured as described above, the substrate is surrounded in a horizontal plane by a first abutment member located at a first reference position, a second abutment member located at a second reference position, and a third abutment member located at a third reference position. These three abutment members are gradually moved closer to the substrate by repeated micro-movements while maintaining the same distance from the center of the substrate support part. During this approaching movement, the abutment members sequentially abut against the substrate, moving the substrate horizontally toward the center of the substrate support part. As a result, the center of the substrate sandwiched between these three abutment members coincides with the center of the substrate support part. [Effects of the Invention]

[0010] As described above, according to the present invention, the center of a disk-shaped substrate placed on the upper surface of a substrate support part can be aligned with the center of the substrate support part simply by repeating the small movements of three abutment members, thereby enabling substrate centering processing to be performed with excellent throughput. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram showing a substrate processing system equipped with an embodiment of a substrate processing apparatus according to the present invention; [Figure 2] 1 is a diagram schematically illustrating a configuration of an embodiment of a substrate processing apparatus. [Figure 3] FIG. 2 is a perspective view showing the configuration of a substrate holding unit and a centering mechanism of the substrate processing apparatus. [Figure 4] 10A to 10C are diagrams illustrating the operation of a centering mechanism. [Figure 5] 5 is a graph showing the variation in load torque with respect to the change in the distance from the center of the base to the protruding portion in the first embodiment. [Figure 6] FIG. 4 is a diagram schematically illustrating the configuration of a second embodiment of a centering device according to the present invention. [Figure 7] FIG. 10 is a diagram schematically illustrating the configuration of a third embodiment of a centering device according to the present invention. [Figure 8] 11 is a graph showing a change in the amount of movement accompanying a change in the distance from the center of the base to the protrusion in the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] 1 is a diagram showing a substrate processing system equipped with an embodiment of a substrate processing apparatus according to the present invention. The substrate processing system 100 includes a substrate processing unit 110 that processes substrates S, and an indexer unit 120 coupled to the substrate processing unit 110. The indexer unit 120 includes a container holder 121 that can hold a plurality of containers C for accommodating substrates S (e.g., FOUPs (Front Opening Unified Pods), SMIF (Standard Mechanical Interface) pods, and OCs (Open Cassettes) that hermetically accommodate a plurality of substrates S), and an indexer robot 122 that accesses the containers C held by the container holder 121 to remove unprocessed substrates S from the container C and store processed substrates S into the container C. Each container C accommodates a plurality of substrates S in a substantially horizontal position.

[0013] The indexer robot 122 comprises a base 122a fixed to the apparatus housing, an articulated arm 122b rotatable about a vertical axis relative to the base 122a, and a hand 122c attached to the tip of the articulated arm 122b. The hand 122c is structured so that a substrate S can be placed on its upper surface and held thereon. Indexer robots having such articulated arms and hands for holding substrates are well known, and therefore a detailed description thereof will be omitted.

[0014] The substrate processing section 110 includes a substrate transfer robot 111 disposed approximately in the center in a plan view, and a plurality of processing units 1 disposed to surround the substrate transfer robot 111. Specifically, the plurality of processing units 1 are disposed facing the space in which the substrate transfer robot 111 is disposed. The substrate transfer robot 111 randomly accesses these processing units 1 to hand over substrates S. Meanwhile, each processing unit 1 performs a predetermined process on the substrate S. In this embodiment, one of these processing units 1 corresponds to the substrate processing apparatus 10 according to the present invention.

[0015] FIG. 2 is a diagram showing a schematic configuration of one embodiment of a substrate processing apparatus. FIG. 3 is a perspective view showing the configuration of a substrate holding unit and a centering mechanism of the substrate processing apparatus. FIG. 4 is a diagram showing a schematic operation of the centering mechanism. The substrate processing apparatus 10 performs bevel etching as an example of the "processing" of the present invention, and supplies a processing liquid to the peripheral portion of the upper surface of a substrate S in a processing chamber. For this purpose, the substrate processing apparatus 10 is equipped with a substrate holding unit 2, a centering mechanism 3 which is the main component of the centering apparatus of the present invention, and a processing liquid supply mechanism 4. The operations of these components are controlled by a control unit 9 which controls the entire apparatus.

[0016] The substrate holder 2 includes a spin base 21, which is a disk-shaped member smaller than the substrate S. The spin base 21 is supported by a rotation support shaft 22 extending downward from the center of its bottom surface so that its top surface 211 is horizontal. The rotation support shaft 22 is rotatably supported by a rotation drive unit 23. The rotation drive unit 23 incorporates a rotation motor 231, which rotates in response to a control command from the control unit 9. This rotation drive force causes the spin base 21 to rotate around a vertical axis AX (dash-dotted line) that passes through the center 21C of the spin base 21 and extends vertically. In FIG. 2, the up-down direction is the vertical direction. The plane perpendicular to the paper surface of FIG. 2 is the horizontal plane. To clarify the directional relationships in FIG. 2 and subsequent drawings, a coordinate system is appropriately provided in which the Z axis is the vertical direction and the XY plane is the horizontal plane.

[0017] The upper surface 211 of the spin base 21 is large enough to support the substrate S, allowing the substrate S to be placed on the upper surface 211 of the spin base 21. Although not shown, the upper surface 211 is provided with a plurality of suction holes, suction grooves, and the like. These suction holes and grooves are connected to a suction pump 24 via a suction pipe 241. When the suction pump 24 operates in response to a control command from the control unit 9, the suction pump 24 applies suction force to the spin base 21. As a result, air is exhausted from between the upper surface 211 of the spin base 21 and the lower surface of the substrate S, and the substrate S is suction-held on the spin base 21. The substrate S thus suction-held is rotated around the vertical axis AX together with the rotation of the spin base 21. Therefore, if the center SC of the substrate S does not coincide with the center 21C of the spin base 21, that is, if the substrate S is eccentric, the quality of the bevel etching process will be reduced.

[0018] Therefore, in this embodiment, a centering mechanism 3 is provided. The centering mechanism 3 performs a centering process while suction by the suction pump 24 is stopped (that is, while the substrate S is horizontally movable on the upper surface 211 of the spin base 21). This centering process eliminates the eccentricity, and the center SC of the substrate S coincides with the center 21C of the spin base 21. The detailed configuration and operation of the centering mechanism 3 will be described later.

[0019] A processing liquid supply mechanism 4 is provided to perform a bevel etching process on the substrate S that has been subjected to the centering process. The processing liquid supply mechanism 4 has a processing liquid nozzle 41, a nozzle movement unit 42 that moves the processing liquid nozzle 41, and a processing liquid supply unit 43 that supplies a processing liquid to the processing liquid nozzle 41. The nozzle movement unit 42 moves the processing liquid nozzle 41 between a retracted position where it is retracted to the side from above the substrate S as shown by the solid line in Figure 2, and a processing position above the peripheral edge of the substrate S as shown by the dotted line in the same figure.

[0020] The processing liquid nozzle 41 is connected to a processing liquid supply unit 43. When an appropriate processing liquid is supplied from the processing liquid supply unit 43 to the processing liquid nozzle 41 positioned at the processing position, the processing liquid is ejected from the processing liquid nozzle 41 onto the peripheral edge of the rotating substrate S. As a result, a bevel etching process using the processing liquid is performed on the entire peripheral edge of the substrate S.

[0021] 2, a splash guard is provided to surround the sides of the substrate holder 2. The splash guard collects droplets of the processing liquid shaken off from the substrate S during the bevel etching process, and effectively prevents the droplets from scattering around the apparatus.

[0022] 2 to 4, the configuration of the centering mechanism 3 will be described. The centering mechanism 3 has the function of horizontally moving and positioning the substrate S on the upper surface 211 of the spin base 21 so that the center SC of the substrate S placed on the upper surface 211 of the spin base 21 coincides with the center 21C of the spin base 21. As shown in Fig. 3, the centering mechanism 3 has a contact member 31 arranged on the X2 direction (right-hand direction in the figure) side of the center 21C of the spin base 21 in the X direction, and contact members 32 and 33 arranged on the X1 direction (left-hand direction in the figure). The centering mechanism 3 also has a movement mechanism 34 for moving the contact members 31 to 33 in the horizontal direction.

[0023] The movement mechanism 34 has a single movement unit 35 for moving the contact member 31, and a multi-movement unit 36 ​​for collectively moving the contact members 32 and 33. With respect to the center 21C of the spin base 21, the single movement unit 35 is disposed on the X2 direction side, while the multi-movement unit 36 ​​is disposed on the X1 direction side.

[0024] The single movement unit 35 has a fixed base 351, a rotary motor 352, a power transmission unit 353, and a slider 354. The rotary motor 352 is attached to the fixed base 351, and the power transmission unit 353 and slider 354 are stacked on the fixed base 351 in this order. The rotary motor 352 is a drive source for moving the abutting member 31 in the X direction. When the rotary motor 352 is activated in response to a control command from the control unit 9, a rotary shaft (not shown) rotates. This rotary shaft extends from the upper part of the fixed base 351 to the power transmission unit 353, and the rotational driving force generated by the rotary motor 352 is transmitted to the power transmission unit 353. The power transmission unit 353 converts the rotational motion corresponding to the rotational driving force into linear motion in the X direction using, for example, a rack-and-pinion structure and transmits it to the slider 354. As a result, the slider 354 reciprocates in the X direction by a distance corresponding to the amount of rotation. As a result, the contact member 31 attached to the upper part of the slider 354 is moved in the X direction in conjunction with the movement of the slider 354.

[0025] The multi-movement unit 36 ​​is basically configured similarly to the single-movement unit 35, except for a partial difference in the structure of the slider 364. Specifically, the multi-movement unit 36 ​​applies a rotational driving force generated by a rotary motor 362 attached to a fixed base 361 to the slider 364 via a power transmission unit 363, moving the slider 364 in the X direction. The upper portion of the slider 364 has two arms 364a and 364b extending in the X2 direction and spaced apart from each other in the Y direction, forming a roughly C-shape in a vertically upward planar view. Abutment members 32 and 33 are attached to the ends of the arms 364a and 364b on the X2 direction, respectively. Therefore, when the rotary motor 362 is actuated in response to a control command from the control unit 9, the slider 364 reciprocates in the X direction by a distance corresponding to the rotation amount of the rotary motor 362, similar to the single-movement unit 35. As a result, the abutment members 32 and 33 attached to the slider 364 move in the X direction in conjunction with the movement of the slider 364.

[0026] Each of the contact members 31 to 33 has a beak-shaped protruding end that faces the substrate S. That is, the protruding portions (tips) of the contact members 31 to 33 have a sharpened shape. Therefore, the contact members 31 to 33 can make point contact with the side surface of the substrate S supported on the upper surface 211 of the spin base 21. When the contact member 31 is moved in the X1 direction by the single moving unit 35, the protruding portion 311 of the contact member 31 moves toward the center 21C of the spin base 21 and comes into contact with the side surface of the substrate S. As described above, in this embodiment, the movement direction D1 of the contact member 31 to come into contact with the substrate S is the X1 direction, which corresponds to the "first horizontal direction" of the present invention. Then, by further moving in the D1 direction after contact, the substrate S is moved horizontally in the X1 direction on the upper surface 211 of the spin base 21 while pressing against the X1 direction. In this embodiment, to facilitate understanding of the invention, an imaginary line VL extending in the X1 direction from the center 21C of the spin base 21 is additionally shown in Figures 3 and 4. This corresponds to the "imaginary line" of the present invention. Below, we will continue to explain the configuration of the centering mechanism 3, making appropriate use of the imaginary line VL.

[0027] The manner in which the abutment members 32 and 33 are moved by the multi-movement unit 36 ​​is partially different from that of the abutment member 31. This is because, in the horizontal plane, the abutment members 32 and 33 are arranged symmetrically with respect to the imaginary line VL and are moved in the X direction while maintaining this arrangement. More specifically, as shown in FIG. 4(a), the abutment member 32 is arranged offset from the imaginary line VL by a predetermined distance W (which is shorter than the radius rs of the substrate S) toward the Y2 direction. On the other hand, the abutment member 33 is arranged on the opposite side of the imaginary line VL from the abutment member 32, i.e., toward the Y1 direction, offset by the same distance W as the abutment member 32. Therefore, when the abutment members 32 and 33 are moved in the X2 direction by the multi-movement unit 36, the protruding portion 321 of the abutment member 32 abuts against the side surface of the substrate on the Y2 direction side of the imaginary line VL, and the protruding portion 331 of the abutment member 33 abuts against the side surface of the substrate on the Y1 direction side of the imaginary line VL. As described above, in this embodiment, the movement direction D2 of the contact member 32 for contacting the substrate S is the X2 direction, which corresponds to the "second horizontal direction" of the present invention. The movement direction D3 of the contact member 33 for contacting the substrate S is also the X2 direction, which corresponds to the "third horizontal direction" of the present invention. Therefore, in order to move the protrusions 311, 321, and 331 while maintaining the same distance from the center 21C of the spin base 21 to each of the protrusions 311, 321, and 331, it is necessary to make the movement amount per unit time different between the contact member 31 and the contact members 32 and 33. This point will be described in detail with reference to FIG. 4, and a centering process using the above-mentioned movement mode will also be described.

[0028] In order to place the substrate S on the upper surface 211 of the spin base 21, it is desirable to position the protruding portions 311, 321, and 331 at the reference position taking into account at least the maximum value of the outer diameter tolerance of the substrate S. For example, for a substrate S with a diameter of 300 mm, the outer diameter tolerance is 0.2 mm. Therefore, the protruding portions 311, 321, and 331 must be 150.1 mm or more away from the center 21C of the spin base 21. In this embodiment, this distance is referred to as the "reference distance r0," and as shown in FIG. 4(a), the reference circle is a circle (dashed line) whose center is the center 21C of the spin base 21 and whose radius is the reference distance r0.

[0029] Next, consider the case where the contact members 31 to 33 are positioned so that the protruding portions 311, 321, and 331 are located on the reference circle, and then the protruding portions 311, 321, and 331 are moved toward the substrate S. In this case, the position of the contact member 31 for locating the protruding portion 311 on the reference circle corresponds to the "first reference position" of the present invention, the position of the contact member 32 for locating the protruding portion 321 on the reference circle corresponds to the "second reference position" of the present invention, and the position of the contact member 33 for locating the protruding portion 331 on the reference circle corresponds to the "third reference position" of the present invention.

[0030] Here, consider the case where contact member 31 is slightly moved in direction D1 (X1 direction) by a first movement amount Δd1 toward substrate S from states in which contact members 31 to 33 are located at the first reference position, second reference position, and third reference position, respectively. If contact members 32 and 33 are correspondingly slightly moved by the same distance in direction D2 (X2 direction), the distances from center 21C of spin base 21 to protruding portions 311, 321, and 331 will become irregular. Therefore, if the slight movements of contact members 31 to 33 are repeated while keeping the movement amounts per unit time constant, center SC of substrate S will not coincide with center 21C of spin base 21.

[0031] In contrast to this, as shown in FIG. 4(b), the distance Δd2 (corresponding to the "second movement amount" of the present invention) by which the contact member 32 is slightly moved and the distance Δd3 (corresponding to the "third movement amount" of the present invention) by which the contact member 33 is slightly moved are set as follows: Δd2=Δd3=r1·cosθ1-r2·cosθ2 =r1·cos(sin -1 (W / r1))- r2·cos(sin -1 (W / r2)) r1=r0 r2=r1-Δd1 however, r1: distance from the center 21C to the protruding portion 321 before the minute movement, θ1: the angle between the imaginary line VL and the straight line connecting the center 21C and the protruding portion 321 before the minute movement, r2: distance from the center 21C to the protruding portion 321 after the minute movement, θ2: the angle between the imaginary line VL and the straight line connecting the center 21C and the protruding portion 321 after the minute movement, W: distance from the imaginary line VL to the contact member 32, In this case, even after the minute movement, the distances from the center 21C of the spin base 21 to the protruding portions 311, 321, and 331 remain constant. By repeating such minute movements, the contact members 31 to 33 approach the substrate S while maintaining the same distances from the center 21C of the spin base 21 to the protruding portions 311, 321, and 331. Then, if eccentricity as shown in FIG. 4 occurs, for example, during the repetition of the minute movements, the contact member 31 first comes into contact with the substrate S and moves the substrate S in the direction D1 (see section (c) of FIG. 4). Subsequently, the contact member 32 comes into contact with the substrate S being pushed by the contact member 31 and moves it horizontally. Then, as shown in section (d) of FIG. 4, when the distance from the center 21C of the spin base 21 to the protruding portions 311, 321, and 331 becomes equal to the radius of the substrate S, the last contact member 33 also comes into contact with the substrate S. In this way, the substrate S is sandwiched between the contact members 31 to 33, the movement of the substrate S is stopped, and the center SC of the substrate S coincides with the center 21C of the spin base 21. In this way, the centering process of the substrate S can be performed.

[0032] In this embodiment having the centering mechanism 3, the control unit 9 controls each section of the substrate processing apparatus 10 to perform the centering process and the subsequent bevel etching process. The control unit 9 includes an arithmetic processing section 91 configured by a computer having a CPU (Central Processing Unit), RAM (Random Access Memory), etc.; a storage section 92 such as a hard disk drive; and a motor control section 93.

[0033] The arithmetic processing unit 91 appropriately reads out a centering program and a bevel etching program stored in advance in the storage unit 92, expands them into RAM (not shown), and performs the centering process and the bevel etching process shown in FIG. 4. In particular, when performing the centering process, the arithmetic processing unit 91 calculates first to third movement amounts Δd1 to Δd3 and controls the rotation motors 352 and 362 of the movement mechanism 34 via the motor control unit 93 based on these movement amounts Δd1 to Δd3. The arithmetic processing unit 91 also calculates the load torque at the single movement unit 35 from the motor current value applied to the rotation motor 352, and calculates the load torque at the multi-movement unit 36 ​​from the motor current value applied to the rotation motor 362. Here, as the distance from the center 21C of the spin base 21 to the protruding portions 311, 321, and 331 (the distance from the center of the base to the protruding portions) changes during repeated minute movements, the load torque fluctuates, for example, as shown in FIG. 5. As shown in the figure, when the distance coincides with the radius rs of the substrate S, i.e., when the contact members 31-33 clamp the substrate S, the load torque increases rapidly almost simultaneously in the single movement unit 35 and the multi-movement unit 36. Therefore, the calculation processing unit 91 determines that the centering process is complete when the load torque exceeds a threshold value, and stops the movement of the contact members 31-33. In this embodiment, the load torque fluctuations are monitored for all motors 352, 362, but the timing for stopping the movement of the contact members 31-33 may also be determined by monitoring only one of the motors. It goes without saying that the load torque may also be calculated based on factors other than the motor current value.

[0034] As described above, in this embodiment, by repeatedly making minute movements of the contact members 31 to 33, the contact members 31 to 33 are gradually brought closer to the substrate S while maintaining the same distance from the center 21C of the spin base 21 to the protruding portions 311, 321, and 331. Then, by sandwiching the substrate S between these three contact members 31 to 33, the center SC of the substrate S is made to coincide with the center 21C of the spin base 21. In this way, the centering process is performed simply by repeatedly making minute movements of the contact members 31 to 33, and the centering process can be performed with excellent throughput.

[0035] Furthermore, the completion of the centering process is confirmed based on the load torque fluctuation, and the movement of the contact members 31 to 33 is immediately stopped. This allows the centering process to be completed at an appropriate timing without damaging the substrate S. This also applies to the embodiments described later.

[0036] As described above, in the substrate processing apparatus 10, the combination of the centering mechanism 3 and the control unit 9 corresponds to the first embodiment of the centering device according to the present invention. That is, the contact members 31 to 33 correspond to examples of the "first contact member," the "second contact member," and the "third contact member," respectively. The control unit 9 corresponds to an example of the "control unit" according to the present invention. The spin base 21 and the center 21C correspond to examples of the "substrate support portion" and the "center of the substrate support portion," respectively. The suction pump 24 corresponds to an example of the "suction portion" according to the present invention.

[0037] In the first embodiment, the two contact members 32, 33 are moved in the D2 direction (X2 direction) and the D3 direction (X2 direction) by the multi-movement unit 36, but instead of the multi-movement unit 36, a single movement unit for the contact member 32 and a single movement unit for the contact member 33 configured similarly to the single movement unit 35 may be provided. In this case, the single movement units provided for the contact members 31 to 33 correspond to examples of the "first single movement unit," "second single movement unit," and "third single movement unit" of the present invention, respectively.

[0038] Furthermore, when a single moving section for the abutment member 32 and a single moving section for the abutment member 33 are provided in this manner, there is no need to unify both the D2 direction and the D3 direction into the X2 direction, and at least one of the D2 direction and the D3 direction may be changed from the X2 direction (second embodiment).

[0039] FIG. 6 is a diagram showing a schematic configuration of a second embodiment of a centering device according to the present invention. The second embodiment differs significantly from the first embodiment in that, instead of the multi-movement unit 36, a single movement unit 37 for the abutting member 32 and a single movement unit 38 for the abutting member 33 are provided, each configured similarly to the single movement unit 35, and in that both the D2 and D3 directions are different from the X2 direction. In this second embodiment, the second and third movement amounts are set individually in the same manner as in columns (a) and (b) of FIG. 4 and the considerations of the second and third movement amounts based thereon. Other configurations and operations are essentially the same as those of the first embodiment.

[0040] In the second embodiment configured as described above, the contact members 31 to 33 sequentially contact the substrate S and sandwich the substrate S while maintaining the same distance from the center 21C of the spin base 21 to the protruding portions 311, 321, and 331. This causes the center SC of the substrate S to coincide with the center 21C of the spin base 21. Therefore, the centering process is performed simply by repeating the minute movements of the contact members 31 to 33, and the centering process can be performed with excellent throughput.

[0041] FIG. 7 is a schematic diagram illustrating the configuration of a third embodiment of a centering device according to the present invention. The third embodiment differs significantly from the first embodiment in the shape of the protruding portions 311, 321, and 331 of the contact members 31 to 33. That is, in the first embodiment, the protruding portions 311, 321, and 331 have a pointed shape. Therefore, wear due to contact with the substrate S is relatively severe, raising concerns about increased replacement frequency. Therefore, as shown in FIG. 7, the protruding portions 311, 321, and 331 may be finished in a semicircular shape. However, in the third embodiment, the contact position of the protruding portion 321 with respect to the substrate S is displaced depending on the amount of movement of the contact member 32 in the D2 direction. The same applies to the contact position of the protruding portion 331. Therefore, the second and third movement amounts in the third embodiment cannot be calculated by simply applying columns (a) and (b) of FIG. 4 and the results of the discussion of the second and third movement amounts based thereon.

[0042] Therefore, in the third embodiment, the reference distance r0 was set to 150.25 mm (=300.5 mm / 2), the diameter of the protruding portions 311, 321, and 331 was set to 20 mm, and plan views were created when the double distance (the distance from the center 21C of the spin base 21 to the protruding portions 311, 321, and 331) was 300.5 mm, 300.2 mm, 300.1 mm, 300 mm, 299.9 mm, 299.8 mm, and 299.5 mm. Note that Fig. 7 shows a plan view when the distance is 300.5 mm (see column (a) in the figure) and a plan view when the distance is 300.2 mm (see column (b) in the figure), and other plan views are omitted. From these plan views, the amount of movement of the contact member 31 and the amount of movement of the contact members 32 and 33 required to reduce the distance stepwise from 300.5 mm were calculated. The results are summarized in Figure 8. For reference, Figure 8 also shows a graph showing the fluctuations in the amount of movement of the contact members 32 and 33 calculated in the first embodiment.

[0043] FIG. 8 is a graph showing the change in the amount of movement associated with changing the distance from the base center to the protruding portions in the third embodiment. As is clear from the graph, in order to reduce the distance from the center 21C of the spin base 21 to the protruding portions 311, 321, and 331 while maintaining the same distance (the distance from the base center to the protruding portions), it is necessary to appropriately change the amount of movement. The graph also indicates that the change in the amount of movement can be approximated by a linear function. Therefore, in the third embodiment, the linear function is pre-stored in the storage unit 92. Meanwhile, when performing the centering process, the calculation processing unit 91 reads the linear function from the storage unit 92. During the centering process, the calculation processing unit 91 obtains the amount of movement based on the linear function and controls the single movement unit 35 and the multi-movement unit 36. Therefore, similar to the first embodiment, the centering process can be performed effectively by the abutting members 31 to 33 while maintaining the same distance from the center 21C of the spin base 21 to the protruding portions 311, 321, and 331. As a result, the same effects as those of the first embodiment can be achieved.

[0044] In addition, in the third embodiment, the protrusions 311, 321, and 331 have a semidisc shape, which makes them less susceptible to wear than the pointed shapes in the first embodiment. This reduces the frequency of replacement of the contact members 31 to 33, thereby reducing the burden on the operator and the running costs.

[0045] The present invention is not limited to the above-described embodiment, and various modifications can be made to the above-described embodiment without departing from the spirit of the present invention. For example, in the above-described embodiment, the clamping of the substrate S between the contact members 31-33, i.e., the completion of the centering process, is detected based on load torque fluctuations. However, this detection may be performed by other methods. For example, sensors such as load cells or strain gauges may be provided on the single movement units 35, 37, 38 or the multi-movement unit 36, and the sensors may be configured to detect stress or strain when the substrate S is clamped between the contact members 31-33 and output a detection signal. In this case, the control unit 9 confirms the clamping of the substrate S between the contact members 31-33 based on the detection signal from the sensors.

[0046] Furthermore, in the third embodiment described above, the calculation processing unit 91 is configured to calculate the amount of movement based on a linear function, but instead of a linear function, the change in the amount of movement may be compiled into a data table and stored in the memory unit 92.

[0047] In the third embodiment, the protruding portions 321 and 331 are finished in a semi-disc shape, but they may be finished in an inclined shape when viewed from the vertical direction. In this way, the configuration in which the protruding portions 311, 321, and 331 are finished in a semi-disc shape or the protruding portions 321 and 331 are finished in an inclined shape may be applied to the second embodiment.

[0048] Furthermore, in the above embodiment, the present invention is applied to a centering device installed in a substrate processing apparatus 10 that performs bevel etching processing, but the centering device according to the present invention can be applied to centering devices and centering methods in general that are installed in substrate processing apparatuses that process disk-shaped substrates while rotating them. [Industrial Applicability]

[0049] The present invention can be applied to a centering technique for aligning the center of a disk-shaped substrate placed on the upper surface of a substrate support part with the center of the substrate support part, and to substrate processing apparatuses in general that use this technique to process substrates. [Explanation of symbols]

[0050] 3...Centering mechanism 4...Processing liquid supply mechanism 9...Control unit (control section) 10...Substrate processing device 21...Spin base (substrate support part) 21C...Center of (spin base) 23...Rotation drive unit 24...Suction pump (suction part) 31...First contact member 32...Second contact member 33...Third contact member 34...Movement mechanism 35, 37, 38...Single moving part 36...Multi-mobile unit 211...(Spin base) top surface 231,352,362...Rotary motor S...Substrate SC: Center (of the board) VL...Virtual line

Claims

1. A centering device that positions a disk-shaped substrate placed on an upper surface of a substrate support part by horizontally moving the substrate on the upper surface of the substrate support part so that the center of the substrate coincides with the center of the substrate support part, a first contact member movable in a first horizontal direction from a first reference position toward the center of the substrate support portion, the first reference position being a reference distance longer than a radius of the substrate from the center of the substrate support portion in a horizontal plane; a second abutment member that is movable in a second horizontal direction different from the direction from a second reference position toward the center of the substrate support portion and that approaches the substrate, the second abutment member being located on an opposite side of the first abutment member with respect to the center of the substrate support portion within the horizontal plane, the second abutment member being deviated from an imaginary line extending from the center of the substrate support portion in the first horizontal direction and being spaced apart from the center of the substrate support portion by the reference distance; a third abutment member, which is movable in the horizontal plane on the opposite side of the first abutment member with respect to the center of the substrate support portion and on the opposite side of the second abutment member with respect to the virtual line, and which is spaced from the center of the substrate support portion by the reference distance, and which is different from the direction from a third reference position toward the center of the substrate support portion and moves toward the substrate; a movement mechanism that moves the first contact member, the second contact member, and the third contact member in the first horizontal direction, the second horizontal direction, and the third horizontal direction, respectively; a control unit that controls the movement mechanism, The control unit repeating minute movements of moving the first contact member, the second contact member, and the third contact member by a first movement amount, a second movement amount, and a third movement amount, respectively, so that distances of the first contact member, the second contact member, and the third contact member from the center of the substrate support portion are kept constant; When it is confirmed that the substrate is sandwiched between the first contact member, the second contact member, and the third contact member, the minute movement is stopped and the centering process for the substrate is completed. A centering device characterized by:

2. 2. The centering device according to claim 1, A centering device, wherein the second horizontal direction and the third horizontal direction are directions parallel to the virtual line.

3. 3. The centering device according to claim 2, the third reference position is symmetrical to the second reference position with respect to the virtual line, The second movement amount and the third movement amount are the same value.

4. 4. The centering device according to claim 3, The moving mechanism is a centering device having a single moving unit that moves the first abutment member in the first horizontal direction, and a multi-moving unit that moves the second abutment member and the third abutment member collectively in the second horizontal direction and the third horizontal direction, respectively.

5. 5. The centering device according to claim 4, the single movement unit has a motor for moving the first contact member, the multi-movement unit has a motor for moving the second contact member and the third contact member, The control unit is a centering device that confirms clamping of the substrate by the first abutment member, the second abutment member, and the third abutment member based on load torque fluctuations in at least one of the plurality of motors.

6. 2. The centering device according to claim 1, The moving mechanism is a centering device having a first single moving unit that moves the first abutment member in the first horizontal direction, a second single moving unit that moves the second abutment member in the second horizontal direction, and a third single moving unit that moves the third abutment member in the third horizontal direction.

7. 7. The centering device according to claim 6, the first single moving unit has a motor for moving the first contact member, the second single moving unit has a motor for moving the second contact member, the third single moving unit has a motor for moving the third contact member, The control unit is a centering device that confirms the clamping of the substrate by the first contact member, the second contact member, and the third contact member based on a load torque fluctuation in at least one of the plurality of motors.

8. 7. A centering device according to claim 1, 2, 3, 4 or 6, a sensor that detects stress or strain generated in the moving mechanism when the substrate is sandwiched between the first contact member, the second contact member, and the third contact member, and outputs a detection signal; The control unit is a centering device that confirms that the substrate is sandwiched between the first contact member, the second contact member, and the third contact member based on the detection signal from the sensor.

9. A centering method for aligning a center of a disk-shaped substrate with a center of a substrate support, comprising: placing the substrate on the upper surface of the substrate support part in a state in which a first abutment member is positioned at a first reference position in a horizontal plane, the first reference position being a reference distance longer than a radius of the substrate from the center of the substrate support part; a second abutment member is positioned at a second reference position on an opposite side of the first abutment member with respect to the center of the substrate support part, the second reference position being off an imaginary line extending from the first reference position through the center of the substrate support part and being the reference distance from the center of the substrate support part; and a third abutment member is positioned at a third reference position on an opposite side of the first abutment member with respect to the center of the substrate support part and on an opposite side of the second abutment member with respect to the imaginary line, the third reference position being the reference distance from the center of the substrate support part; a step of repeating minute movements, while the substrate is placed on the upper surface of the substrate support part so as to be freely movable horizontally, of moving the first abutment member in a first horizontal direction from the first reference position toward the center of the substrate support part, moving the second abutment member by a second movement amount in a second horizontal direction different from the direction from the second reference position toward the center of the substrate support part and approaching the substrate, and moving the third abutment member by a third movement amount in a third horizontal direction different from the direction from the third reference position toward the center of the substrate support part and approaching the substrate, so that distances of the first abutment member, the second abutment member, and the third abutment member from the center of the substrate support part are kept constant; a step of stopping the minute movement and terminating the centering process for the substrate when it is confirmed that the substrate has been sandwiched between the first contact member, the second contact member, and the third contact member during the repetition of the minute movement; A centering method comprising:

10. a substrate support portion having an upper surface for supporting a substrate in a horizontal position; A centering device according to any one of claims 1 to 8; a suction unit that evacuates the space between the substrate positioned by the centering device and the substrate support unit to suction-hold the substrate on the substrate support unit; a rotation drive unit that rotates the substrate support unit that suction-holds the substrate around a center of the substrate support unit; a processing liquid supply mechanism for supplying a processing liquid to a peripheral portion of the substrate, which is rotated around the center of the substrate support unit integrally with the substrate support unit; A substrate processing apparatus comprising:

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