Centering device and substrate processing device

Abstract

To prevent reduction in centering accuracy of a substrate by suppressing influences caused by a change of an ambient temperature.SOLUTION: A multi-movement section integrally moves a second abutment member and a third abutment member in a first horizontal direction in a state where a center of a substrate holding section is enclosed by the second abutment member and the third abutment member together with a first abutment member in a planar view from a vertically upper side. The multi-movement section includes a multi-support section which integrally supports the second abutment member and the third abutment member, and a slide member which is attached to a guide member which is disposed in a stationary manner at a predetermined position in the first horizontal direction in a freely slidable manner while being coupled with the multi-support section. The multi-support section and the slide member consist of materials where a difference dLE of mutual linear expansion coefficients satisfies the following inequality dLE<AE / (0.8597×dTM).SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] This invention relates to a centering technique for aligning the center of a disk-shaped substrate placed on the upper surface of a substrate holder with the center of the substrate holder, and to a substrate processing apparatus that processes the substrate using this 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 (equivalent to an example of a "substrate holder" in the present invention) and held by suction. In this case, if the center of the spin chuck and the center of the substrate are misaligned, this will result in a decrease in processing quality. Therefore, the apparatus is equipped with a centering device.

[0003] The centering device performs a so-called centering process, which reduces the eccentricity of the substrate relative to the spin chuck. More specifically, this centering device uses three abutment members to surround the substrate placed on the upper surface of the substrate holder. Among these, the first abutment member is provided so as to be movable in a first horizontal direction from a first reference position toward the center of the substrate holder in a horizontal plane, a reference distance from the center of the substrate holder that is longer than the radius of the substrate. Meanwhile, the remaining second and third abutment members are provided on the opposite side of the first abutment member with respect to the center of the substrate holder in a horizontal plane, as follows: The second abutment member is provided so as to be movable in a second horizontal direction, different from the direction from the second reference position toward the center of the substrate holder and approaching the substrate, away from an imaginary line extending from the center of the substrate holder in the first horizontal direction and a reference distance from the center of the substrate holder. The third abutment member is located on the opposite side of the imaginary line from the second abutment member, a reference distance from the center of the substrate holder, and is movable in a third horizontal direction different from the direction from the third reference position toward the center of the substrate holder, and moving toward the substrate. Repeated slight movements of these three abutment members gradually move closer to the substrate while maintaining the same distance from the center of the substrate holder. During this approaching movement, the abutment members sequentially abut against the substrate, moving the substrate horizontally toward the center of the substrate holder. As a result, when the substrate is sandwiched between these three abutment members, the center of the substrate coincides with the center of the substrate holder, completing the centering process. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-114594 Summary of the Invention [Problem to be solved by the invention]

[0005] In the centering device described above, the positioning of the substrate in the X direction, which is parallel to the first horizontal direction, is achieved by clamping the substrate between the first abutment member and the second and third abutment members. Meanwhile, the positioning of the substrate in the Y direction, which is perpendicular to the X direction, is achieved by the second and third abutment members. For example, if the center of the substrate is offset from the center of the substrate holder in the Y2 direction in Patent Document 1, the second abutment member will abut against the edge surface of the substrate during repeated micro-movements. Further micro-movements while maintaining this abutment state displace the substrate so that the center of the substrate shifts in the Y1 direction, and eventually the third abutment member abuts against the edge surface of the substrate. Centering in the Y direction is achieved through this operation. In other words, the center of the substrate in the Y direction is determined by the relative positions of the second and third abutment members in the horizontal plane.

[0006] These second and third contact members are supported by a support member (corresponding to an example of the "multi-support member" of the present invention) that is approximately C-shaped when viewed from above, and the above-mentioned positional relationship is maintained constant. However, when the temperature inside the substrate processing apparatus in which the centering device is installed, i.e., the ambient temperature around the centering device, changes, the above-mentioned positional relationship can change. This is one of the main causes of reduced centering accuracy.

[0007] The present invention has been made in view of the above-mentioned problems, and has as its object to improve the centering accuracy of a substrate by suppressing the influence of changes in the ambient temperature. [Means for solving the problem]

[0008] A first aspect of the present invention is a centering device comprising: a first abutment member capable of abutting against an edge surface of a disk-shaped substrate placed in a horizontal position on the upper surface of a substrate holding part; a single movement unit that moves the first abutment member in a first horizontal direction; second and third abutment members that sandwich the substrate holding part and are capable of abutting against the edge surface of the substrate from the opposite side of the first abutment member; a multi-movement unit that moves the second and third abutment members together in the first horizontal direction while the second and third abutment members surround the center of the substrate holding part in a plan view from vertically above; and a multi-movement unit that moves the second and third abutment members together in the first horizontal direction while the first, second, and third abutment members sandwich the substrate from the first horizontal direction and adjusts the position of the substrate on the substrate holding part so that the center of the substrate coincides with the center of the substrate holding part. and a control unit that controls the single movement unit and the multi movement unit so as to determine the linear expansion coefficient of the multi movement unit, wherein the multi movement unit has a multi support unit that integrally supports the second contact member and the third contact member, a guide member that extends in the first horizontal direction, a slide member that is attached to the multi support unit and slidably in the first horizontal direction relative to the guide member that is fixedly disposed at a predetermined position while being connected to the multi support unit, a drive unit that generates a drive force for moving the multi support unit in the first horizontal direction, and a power transmission unit that transmits the drive force to the multi support unit, wherein when an eccentricity of the substrate with respect to the substrate holding unit that is allowable for a change in ambient temperature dTM is defined as an allowable eccentricity AE, the multi support unit and the slide member have a linear expansion coefficient that satisfies the following inequality: dLE <AE / (0.8597×dTM) The present invention is characterized in that it is made of a material that satisfies the above.

[0009] A second aspect of the present invention is a centering device comprising: a first abutment member capable of abutting against an edge surface of a disk-shaped substrate placed in a horizontal position on the upper surface of a substrate holding part; a single movement unit that moves the first abutment member in a first horizontal direction; second and third abutment members that sandwich the substrate holding part and are capable of abutting against the edge surface of the substrate from the opposite side of the first abutment member; a multi-movement unit that moves the second and third abutment members together in the first horizontal direction while the second and third abutment members surround the center of the substrate holding part in a plan view from vertically above; and a base on the substrate holding part so that the center of the substrate coincides with the center of the substrate holding part when the first, second, and third abutment members sandwich the substrate in the first horizontal direction. and a control unit that controls the single moving unit and the multi-moving unit to position the plate, wherein the multi-moving unit has a multi-support unit that integrally supports the second abutment member and the third abutment member, a guide member extending in the first horizontal direction, a slide member that is attached so as to be freely slidable in the first horizontal direction relative to the guide member that is fixedly arranged at a predetermined position with the multi-support unit stacked and connected on its upper surface, a drive unit that generates a drive force to move the multi-support unit in the first horizontal direction, and a power transmission unit that transmits the drive force to the multi-support unit, wherein the multi-support unit and the slide member have shapes that are plane-symmetrical with respect to a vertical imaginary plane that includes the center of the substrate holding unit and is parallel to the first horizontal direction.

[0010] Furthermore, a third aspect of the present invention is a substrate processing apparatus characterized by comprising: a substrate holding section having an upper surface that supports a horizontally oriented substrate; the above-mentioned centering device; a suction section that evacuates the space between the substrate positioned by the centering device and the substrate holding section to adsorb and hold the substrate on the substrate holding section; a rotation drive section that rotates the substrate holding section that adsorbs and holds the substrate around the center of the substrate holding section; 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 holding section integrally with the substrate holding section.

[0011] In this invention, similar to the centering device described in Patent Document 1, the first abutment member, the second abutment member, and the third abutment member sandwich the substrate from a first horizontal direction to center the substrate. In particular, the second abutment member and the third abutment member are respectively located at one end and the other end of the multi-support portion and move integrally with the multi-support portion. This raises concerns about deterioration of centering accuracy due to changes in the ambient temperature of the centering device. However, the present invention employs at least one of the following: selection of materials for the multi-support portion and the slider member, and plane-symmetrical finishing of the multi-support portion and the slider member with respect to a vertical imaginary plane (symbol VS in Figure 4, which will be described later). As a result, deterioration of centering accuracy due to changes in the ambient temperature is suppressed. [Effects of the Invention]

[0012] As described above, according to the present invention, it is possible to suppress the influence of changes in the ambient temperature and prevent a decrease in the centering accuracy of the substrate. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a plan view showing a schematic configuration of a substrate processing system equipped with a first embodiment of a substrate processing apparatus according to the present invention. [Figure 2] 1 is a diagram schematically illustrating a configuration of a first embodiment of a substrate processing apparatus. [Figure 3] FIG. 2 is a perspective view partially showing the configuration of a substrate holding unit and a centering mechanism of the substrate processing apparatus. [Figure 4] FIG. 2 is a perspective view showing the configuration of a multi-movement unit, which is one of the main components of the centering mechanism. [Figure 5] 10 is a graph showing the amount of change in centering accuracy caused by a 1° C. change in the ambient temperature of the centering mechanism. [Figure 6] FIG. 10 is a perspective view showing the configuration of a multi-movement unit provided in a second embodiment of a centering device according to the present invention. [Figure 7]FIG. 10 is a perspective view showing the configuration of a multi-movement unit equipped in a third embodiment of a centering device according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] FIG. 1 is a plan view showing the schematic configuration of a substrate processing system equipped with a first embodiment of a substrate processing apparatus according to the present invention. This is not an external view of the substrate processing system 100, but a schematic view showing the internal structure of the substrate processing system 100 by excluding the exterior wall panels and other components. The substrate processing system 100 is a single-wafer processing apparatus installed, for example, in a clean room, for processing substrates S, each of which has a circuit pattern or the like (hereinafter referred to as a "pattern") formed on only one main surface. The substrates are processed using a processing solution in a processing unit installed in the substrate processing system 100. In this specification, the pattern-formed surface (one main surface) of the two main surfaces of a substrate on which a pattern is formed is referred to as the "front surface," and the opposite main surface on which no pattern is formed is referred to as the "rear surface." The surface facing downward is referred to as the "lower surface," and the surface facing upward is referred to as the "upper surface." In this specification, the "pattern-formed surface" refers to the surface of a substrate on which a concave-convex pattern is formed in any region.

[0015] Here, the "substrate" in this embodiment can be any of various substrates, such as semiconductor wafers, glass substrates for photomasks, glass substrates for liquid crystal displays, glass substrates for plasma displays, substrates for FEDs (Field Emission Displays), substrates for optical disks, substrates for magnetic disks, substrates for magneto-optical disks, etc. The following description will be given with reference to the drawings, taking as an example a substrate processing apparatus used primarily for processing semiconductor wafers, but the invention can also be applied to processing the various substrates exemplified above.

[0016] As shown in FIG. 1, the substrate processing system 100 has a substrate processing area 110 where disk-shaped substrates S are processed. An indexer unit 120 is provided adjacent to the substrate processing area 110. The indexer unit 120 has a container holder 121 that can hold a plurality of containers C for accommodating the substrates S (such as a FOUP (Front Opening Unified Pod), an SMIF (Standard Mechanical Interface) pod, or an OC (Open Cassette) that accommodates a plurality of substrates S in a sealed state). The indexer unit 120 also has an indexer robot 122 that accesses the containers C held in the container holder 121 to remove unprocessed substrates S from the container C or store processed substrates S in the container C. Each container C accommodates a plurality of substrates S in a substantially horizontal position.

[0017] 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.

[0018] In the substrate processing area 110, a mounting table 112 is provided so that a substrate S from an indexer robot 122 can be placed thereon. In addition, a substrate transfer robot 111 is arranged approximately in the center of the substrate processing area 110 in a plan view. Furthermore, a plurality of processing units 1 are arranged surrounding the substrate transfer robot 111. The substrate transfer robot 111 randomly accesses these processing units 1 to transfer the substrate 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.

[0019] FIG. 2 is a diagram showing a schematic configuration of a first embodiment of a substrate processing apparatus. FIG. 3 is a perspective view showing a portion of the configuration of a substrate holding unit and a centering mechanism of the substrate processing apparatus. The substrate processing apparatus 10 is an apparatus that 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 device 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.

[0020] 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 (dashed 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.

[0021] 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 and grooves. These suction holes and grooves are connected to a suction pump 24 via a suction pipe 241. The suction pump 24 functions as an example of a "suction unit" of the present invention. 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 rotates around the vertical axis AX along 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, i.e., if the substrate S is eccentric, the quality of the bevel etching process will be reduced.

[0022] Therefore, in this embodiment, a centering mechanism 3 is provided, which functions as a "centering device" according to the present invention by working in cooperation with the control unit 9. The centering mechanism 3 has a measurement unit 37 that measures the peripheral edge of the substrate S held by suction on the spin base 21. As shown in FIG. 3 , the measurement unit 37 is positioned at the peripheral edge of the substrate S held by suction on the spin base 21 and is capable of acquiring peripheral information regarding the peripheral edge of the substrate S. Furthermore, in the radial direction D4 of the spin base 21, the measurement unit 37 is movable to a retracted position spaced apart from the peripheral edge of the substrate S. For example, the edge detection sensor described in Japanese Patent Application Laid-Open No. 2021-54562 can be used as the measurement unit 37. More specifically, the measurement unit 37 detects the edge position of the substrate S in the radial direction of the spin base 21 while the substrate S rotates at least once around the vertical axis AX together with the rotation of the spin base 21, and outputs an edge detection signal indicating the edge position as peripheral information to the control unit 9. Therefore, by analyzing the edge detection signal, it is possible to determine the amount of eccentricity of the center SC of the substrate S in the X and Y directions from the center 21C of the spin base 21. In addition to the edge detection sensor, an imaging unit that images the peripheral edge of the substrate S may be used as the measurement unit 37. In this case, the continuous images captured by the imaging unit while the substrate S rotates at least once around the vertical axis AX together with the rotation of the spin base 21 correspond to the peripheral edge information. Since methods for deriving the amount of eccentricity in the X and Y directions based on the edge detection signal and the continuous images of the peripheral edge are well known, a detailed description thereof will be omitted here.

[0023] The spin base 21 rotates while suction-holding the substrate S. When suction by the suction pump 24 is stopped, the substrate S becomes movable horizontally on the upper surface 211 of the spin base 21. In this state, a centering process is performed. 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 basic operation of the centering mechanism 3, including the attitude adjustment, is the same as that of the device described in Patent Document 1. Furthermore, even after the centering process, if the amount of eccentricity exceeds an allowable value, the reference position is adjusted based on the amount of eccentricity, which is also the same as that of the device described in Patent Document 1. However, in this embodiment, in order to suppress a decrease in centering accuracy due to changes in the ambient temperature of the centering mechanism 3, some of the configuration of the centering mechanism 3 differs from that of the device described in Patent Document 1. This point will be described in detail later.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] Next, the configuration of the centering mechanism 3 will be described with reference to Figures 2 to 5. 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 Figure 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.

[0028] The movement mechanism 34 has a single movement unit 35 for moving the contact member 31 and a multi-movement unit 36 ​​for moving the contact members 32 and 33 collectively. With respect to the center 21C of the spin base 21, the single movement unit 35 is disposed on the X2 side, while the multi-movement unit 36 ​​is disposed on the X1 side. The single movement unit 35 and the multi-movement unit 36 ​​differ only in the shape and size of the support members that support the contact members, and are otherwise basically identical in configuration. Therefore, the following description will focus on the configuration of the multi-movement unit 36, which is directly related to the technical problem of the present invention, and only a brief description of the configuration of the single movement unit 35 will be provided.

[0029] FIG. 4 is a perspective view showing the configuration of a multi-movement unit, which is one of the main components of the centering mechanism. In the multi-movement unit 36, a base member 361 is fixed to a frame (not shown) of the substrate processing apparatus 10. The base member 361 has a motor base portion 361a and a linear guide base portion 361b. A motor 362 is attached to the motor base portion 361a with its rotation axis facing the linear guide base portion 361b. A linear guide 363, such as an LM Guide (registered trademark), is attached to the linear guide base portion 361b. The linear guide 363 has a rail 363a extending in the X direction and a block 363b slidably mounted in the X direction along the rail 363a. In this embodiment, the block 363b is fixed at a predetermined position on the upper surface of the linear guide base portion 361b with fasteners such as bolts. The rail 363a is mounted above the block 363b so as to be reciprocable in the X direction relative to the block 363b. That is, in this embodiment, the rail 363a and the block 363b correspond to the "slide member" and the "guide member" of the present invention, respectively. Of course, the relationship between the rail 363a and the block 363b may be reversed. That is, the linear guide base portion 361b may be finished in a shape extending in the X direction, and the rail 363a may be fixedly disposed on its upper surface, while the block 363b may be configured to be reciprocable in the X direction relative to the rail 363a. In this case, the rail 363a and the block 363b correspond to the "guide member" and the "slide member" of the present invention, respectively.

[0030] In the first embodiment, as shown in FIG. 4, a multi-support part 364 is attached to a rail 363a that functions as a slide member. The multi-support part 364 includes a slide base 364a that is stacked and fixed on the upper surface of the rail 363a, and a multi-support member 364b that is stacked and fixed on the slide base 364a. In this embodiment, the slide base 364a and the multi-support member 364b are independent plate materials of the same composition, and the multi-support part 364 is formed by connecting them. Of course, a molded body in which the slide base 364a and the multi-support member 364b are integrally molded may also be used as the multi-support part 364. Alternatively, the multi-support part 364 may be formed only by the multi-support member 364b. In this case, the multi-support member 364b is directly attached to the rail 363a.

[0031] Similar to the device described in Patent Document 1, the multi-support member 364b has a substantially C-shape in plan view from above. A second abutment member 32 is attached to an end 364b2 of the multi-support member 364b on the Y2 side, with its abutment surface 321 facing the substrate S on the spin base 21. A third abutment member 33 is attached to an end 364b1 of the multi-support member 364b on the Y1 side, with its abutment surface 331 facing the substrate S on the spin base 21. As will be described next, when a driving force generated by the motor 362 is applied to the multi-support member 364 via a power transmission unit 365, the second abutment member 32 and the third abutment member 33 move in the X direction integrally with the multi-support member 364.

[0032] As shown in FIG. 4, the power transmission unit 365 has a pinion gear 365a attached to the rotation shaft of the motor 362 and a rack gear 365b that can mesh with the pinion gear 365a. The rack gear 365b is attached to the multi-support unit 364 with its teeth 365b1 aligned in the X direction facing the pinion gear 365a and meshing with the pinion gear 365a. Therefore, when the motor 362 operates in response to a rotation command from a motor control unit 93 provided in the control unit 9 that controls the entire device, the driving force generated by the motor 362 is transmitted to the multi-support unit 364 via the pinion gear 365a and the rack gear 365b. As a result, as the multi-support unit 364 moves in the X2 direction, the second abutment member 32 and the third abutment member 33 move in the D2 direction and the D3 direction, respectively.

[0033] As shown in FIG. 3 , the single movement unit 35 has a single support unit 351 that is generally I-shaped in plan view, similar to the device described in Patent Document 1. A first contact member 31 is attached to the end of the single support unit 351 in the X1 direction, with its contact surface 311 facing the substrate S on the spin base 21. Although not shown, the single movement unit 35 also includes a base member, a motor, a linear guide, and a power transmission unit, similar to the multi-movement unit 36, to move the single support unit 351 in the X direction. Therefore, when the motor of the single movement unit 35 operates in response to a rotation command from the motor control unit 93, the rotation is transmitted to the single support unit 351. As a result, the first contact member 31 moves in the D1 direction as the single support unit 361 moves in the X1 direction.

[0034] The single movement unit 35 and multi-movement unit 36 ​​configured as described above are controlled by a control unit 9, and similar to the device described in Patent Document 1, a centering process is performed by sandwiching the substrate S between the three contact members 31 to 33. This control unit 9 has an arithmetic processing unit 91 configured by a computer having a CPU (Central Processing Unit), RAM (Random Access Memory), etc., a storage unit 92 such as a hard disk drive, and a motor control unit 93, and performs a bevel etching process in addition to the centering process.

[0035] The arithmetic processing unit 91 appropriately reads out a centering program, a bevel etching program, and the like stored in advance in the storage unit 92, expands them into RAM (not shown), and executes the centering process and the bevel etching process. In particular, when performing the centering process, the arithmetic processing unit 91 controls the single movement unit 35 and the multi-movement unit 36, similar to the device described in Patent Document 1. More specifically, the single movement unit 35 slightly moves the first contact member 31, and the multi-movement unit 36 ​​slightly moves the second contact member 32 and the third contact member 33, so that the distances from the center 21C of the spin base 21 of the first contact member 31, the second contact member 32, and the third contact member 33 are kept constant. This slight movement is repeated until the first contact member 31, the second contact member 32, and the third contact member 33 have all been brought into contact with the substrate S.

[0036] The calculation processor 91 also calculates the load torque at the single movement unit 35 from the motor current value applied to a motor (not shown) equipped in the single movement unit 35, and calculates the load torque at the multi-movement unit 36 ​​from the motor current value applied to the motor 362 (FIG. 4). Here, the load torque fluctuates as the distance from the center 21C of the spin base 21 to the contact surfaces 311, 321, and 331 (the distance from the base center to the contact surfaces) changes while the minute movements are repeated. However, when this distance matches the radius of the substrate S, that is, when the contact members 31 to 33 sandwich the substrate S, the load torque increases rapidly almost simultaneously at the single movement unit 35 and the multi-movement unit 36. Therefore, the calculation processor 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 to 33.

[0037] The centering mechanism 3 positions the substrate S on the spin base 21 in the X direction by sandwiching the substrate S between the contact members 31 to 33 so that the center SC of the substrate S coincides with the center 21C of the spin base 21. To stably perform this centering process inside the substrate processing apparatus 10, that is, to maintain excellent centering accuracy even when the ambient temperature of the centering mechanism 3 changes, the configuration and arrangement of each part of the centering mechanism 3 were examined. As a result, the inventors of the present application found that in order to suppress the effect of the ambient temperature change on the centering accuracy, it is important that the multi-movement unit 36 ​​satisfy at least one of the material selection requirements and the symmetrical shape requirements described in detail below.

[0038] The material selection requirement refers to selecting the constituent materials of the multi-support portion 364 and the rail 363a so that the difference between the linear expansion coefficient of the multi-support portion 364 and the linear expansion coefficient of the rail 363a (slider member) is equal to or less than a certain value. Because the multi-support portion 364 and the rail 363a are in close contact with each other, if they are made of different materials, warping may occur at the contact body between the multi-support portion 364 and the rail 363a due to a bimetal phenomenon caused by changes in ambient temperature. As the amount of warping increases, the amount of displacement of the second contact member 32 and the third contact member 33 from their preset positions also increases. As a result, the amount of displacement from the target centering position also increases, which can deteriorate centering accuracy.

[0039] Therefore, the inventors of the present application measured the amount of change in the centering position per 1°C temperature change for the following two cases, Cases A and B. Then, they compiled the measurement results and Case C (zero change) in which the linear expansion coefficient is the same and no warping occurs, into a graph. <Case A> The linear guide 363 is composed of a rail 363a and a block 363b. The linear guide 363 is an LM guide (linear expansion coefficient: 12×10 6 / °C), and the multi-support part 364 is made of aluminum (linear expansion coefficient: 23.5×10 6 / °C). In this case, the difference in the linear expansion coefficient dLE is 11.5 × 10 6 / °C, and the amount of change in centering position per 1°C temperature change was 10.545 μm. <Case B> The linear guide 363, which is composed of a rail 363a and a block 363b, is an LM guide (linear expansion coefficient: 12×10 6 / °C), and the multi-support part 364 is made of SUS304 (stainless steel, linear expansion coefficient: 17.3 × 10 6 / °C). In this case, the difference in the linear expansion coefficient dLE is 5.3 × 10 6 / °C, and the amount of change in centering position per 1°C temperature change was 3.636 μm. <Case C> As the linear guide 363 composed of the rail 363a and the block 363b, an LM guide (linear expansion coefficient: 12×10 6 / °C) was used, and the multi-support part 364 was made of a material having the same linear expansion coefficient as that of the LM guide. In this case, the difference dLE in the linear expansion coefficient is zero, and the amount of change in the centering position per 1°C change in temperature is theoretically zero.

[0040] FIG. 5 is a graph showing the amount of change in centering accuracy due to a 1°C change in the ambient temperature of the centering mechanism. From the three points in the graph, when a linear function showing the amount of change in the centering position with respect to the difference dLE in the linear expansion coefficient is derived, y = 0.8597×dLE … Equation (1) is obtained. That is, when the ambient temperature of the centering mechanism 3 arranged inside the substrate processing apparatus 10 changes by an amount dTM, the amount of change in the centering position (deterioration of centering accuracy) due to the difference in the linear expansion coefficient is (amount of change in centering position) = 0.8597×dLE×dTM … Equation (2) Here, when the allowable amount of eccentricity (amount of change in centering position) with respect to the change amount dTM of the ambient temperature is defined as the allowable eccentricity AE, the following inequality AE < 0.8597×dLE×dTM … Equation (3) By satisfying this, the deterioration of centering accuracy due to the bimetal phenomenon can be suppressed within the range of the allowable eccentricity AE. Therefore, it is preferable that the multi-support part 364 and the rail 363a (slider member) are made of a material that satisfies the following inequality dLE < AE / (0.8597×dTM) … Equation (4) For example, when it is necessary to suppress the centering accuracy to 20 μm or less under the condition that the change amount dTM of the ambient temperature is 10°C, the material can be selected so that the difference dLE in the linear expansion coefficient is 2.326×10 6 / °C or less.

[0041] Here, it is ideal to configure the linear guide 363 and the multi-support portion 364 using the same material so that the difference dLE in linear expansion coefficients is zero, but if the constituent materials are different, it is desirable to select them taking into consideration the total weight and surface area of ​​the linear guide 363 and the multi-support portion 364, while assuming that the difference dLE in linear expansion coefficients satisfies the above inequality. Therefore, in the first embodiment, the materials for the linear guide 363 and the multi-support portion 364 are set so that this material selection requirement is satisfied.

[0042] Next, the symmetrical shape requirement will be described. The symmetrical shape requirement requires that the multi-support portion 364 and the rail 363a (slide member) be shaped in plane symmetry with respect to a vertical imaginary plane VS, as shown in FIG. 4 . Here, the vertical imaginary plane VS refers to a vertical plane that includes the center 21C of the spin base 21 and is parallel to the X direction, as indicated by the dashed-dotted line in FIG. 4 . By having such symmetry, even if a bimetal phenomenon occurs, deformation of the multi-support portion 364 and the rail 363a in the Y direction can be eliminated or suppressed, and the relative positional relationship between the second contact member 32 and the third contact member 33 in the Y direction can be maintained. As a result, deterioration of centering accuracy can be suppressed. Of course, it is more preferable to shape the linear guide 363, including not only the rail 363a but also the block 363b, in plane symmetry with respect to the vertical imaginary plane VS. In the first embodiment, as shown in FIG. 4 , the symmetrical shape requirement is satisfied.

[0043] As described above, in the first embodiment, the X direction and the Y direction correspond to the "first horizontal direction" and the "second horizontal direction," respectively, of the present invention. The motor 362 corresponds to an example of a "drive unit" of the present invention. The pinion gear 365a and the rack gear 365b correspond to an example of a "first power transmission member" and a "second power transmission member," respectively, of the present invention. The control unit 9 functions as a "control unit" of the present invention. The end 364b2 on the Y2 direction side of the multi-support member 364b corresponds to an example of a "one end in the second horizontal direction" of the present invention, and the end 364b1 on the Y1 direction side of the multi-support member 364b corresponds to an example of a "other end in the second horizontal direction" of the present invention.

[0044] In the above embodiment, as shown in FIG. 4, the rack gear 365b is attached only to the side surface of the slide base 364a of the multi-support portion 364 on the Y1 direction side. Therefore, as shown in FIG. 6, a dummy part 365c of the rack gear 365b having the same structure as the rack gear 365b may be attached to the side surface of the slide base 364a on the Y2 direction side (second embodiment). For example, a part identical to the rack gear 365b may be used as the dummy part 365c, and this part may be attached to the slide base 364a without meshing with the pinion gear 365a. This makes not only the multi-support portion 364 and the rail 363a (slide member), but also the components attached to the multi-support portion 364 (= 365b + 365c) have shapes that are plane-symmetrical with respect to the vertical imaginary plane VS, thereby more reliably suppressing deterioration of centering accuracy.

[0045] Figure 7 is a perspective view showing the configuration of a multi-movement unit equipped in a third embodiment of a centering device according to the present invention. This third embodiment differs significantly from the first embodiment (Figure 4) and the second embodiment (Figure 6) in that linear guides 363 and power transmission units 365 are arranged in the vertical direction, and that slide bases 364a of multi-support units 364 extend in the vertical direction along the arrangement of linear guides 363 and power transmission units 365 and are connected to rack gears 365b and rails 363a (slide members). The configuration of multi-movement unit 36 ​​will be described in detail below, focusing on these differences.

[0046] In the third embodiment, a base member 361 is fixed to a frame (not shown) of the substrate processing apparatus 10. In the base member 361, a linear guide base member 361b is provided above a motor base member 361a. A motor 362 is attached to the motor base member 361a with its rotation axis facing a slide base 364a. On the other hand, a linear guide 363, such as an LM Guide (registered trademark), is attached to the linear guide base member 361b. The linear guide 363 has a rail 363a extending in the X direction and a block 363b slidably provided in the X direction along the rail 363a. In this embodiment, as shown in FIG. 7, the block 363b and the rail 363a are arranged so as to be sandwiched in this order between the linear guide base member 361b and the slide base 364a. The block 363b is fixed at a predetermined position on the side of the linear guide base member 361b by fasteners such as bolts. Meanwhile, the rail 363a is connected to a slide base 364a so as to be reciprocatable in the X direction relative to the block 363b. Furthermore, a multi-support member 364b is attached to the upper end of the slide base 364a. Therefore, the multi-support portion 364 is reciprocatable in the X direction relative to the block 363b together with the rail 363a. When the driving force generated by the motor 362 is applied to the multi-support portion 364 via the power transmission portion 365, the second abutment member 32 and the third abutment member 33 move in the X direction together with the multi-support portion 364.

[0047] 7, in the third embodiment, the slide base 364a and the multi-support member 364b are independent plate materials of the same composition, and are connected to form the multi-support part 364. Of course, a molded body in which the slide base 364a and the multi-support member 364b are integrally molded may also be used as the multi-support part 364.

[0048] As shown in FIG. 7, the power transmission unit 365 has a pinion gear 365a attached to the rotation shaft of the motor 362 and a rack gear 365b attached to the slide base 364a below the linear guide 363. The rack gear 365b is oriented such that teeth 365b1 aligned in the X direction face the pinion gear 365a, and the teeth 365b1 mesh with the pinion gear 365a. Therefore, when the motor 362 operates in response to a rotation command from a motor control unit 93 provided in the control unit 9, the driving force generated by the motor 362 is transmitted to the multi-support unit 364 via the pinion gear 365a and the rack gear 365b. As a result, as the multi-support unit 364 moves in the X2 direction, the second abutment member 32 and the third abutment member 33 move in the D2 direction (FIG. 3) and the D3 direction (FIG. 3), respectively.

[0049] In the multi-movement section 36 configured in this manner, the material selection requirements are satisfied. That is, the materials constituting the multi-support section 364 and the rail 363a (slider member) are selected so that the above formula (4) is satisfied. Therefore, as in the first and second embodiments, deterioration of centering accuracy due to the bimetal phenomenon can be effectively suppressed.

[0050] Furthermore, the third embodiment employs a so-called vertically-placed structure in which linear guide 363 and power transmission unit 365 are arranged in the vertical direction along slide base 364a that hangs down from multi-support member 364b. As a result, the centering mechanism 3 according to the third embodiment can be made smaller in size in the horizontal plane than the first embodiment (FIG. 4) and the second embodiment (FIG. 6) that employ a so-called horizontally-placed structure in which slide base 364a, to whose side surface rack gear 365b of power transmission unit 365 is attached, is stacked and arranged horizontally on the top surface of linear guide 363.

[0051] As described above, in the third embodiment, slide base 364a and multi-support member 364b correspond to examples of the "hanging member" and the "horizontal support member" of the present invention, respectively.

[0052] The present invention is not limited to the above-described embodiments, and various modifications can be made to the above-described embodiments without departing from the spirit of the present invention. For example, although the first and second embodiments are configured to satisfy both the material selection requirement and the symmetrical shape requirement, they may be configured to satisfy only one of them.

[0053] Furthermore, when the single moving unit 35 is placed horizontally, it may be configured to satisfy at least one of the material selection requirement and the symmetrical shape requirement. When the single moving unit 35 is placed vertically, it may be configured to satisfy the material selection requirement. By using such a single moving unit 35, it is possible to further improve centering accuracy.

[0054] In the above embodiment, the present invention is applied to a centering device installed in the substrate processing apparatus 10 that performs bevel etching, but the centering device according to the present invention can be applied to general centering techniques installed in substrate processing apparatuses that process disk-shaped substrates while rotating them. Also, the centering device according to the present invention may be used alone. [Industrial Applicability]

[0055] 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 holding part with the center of the substrate holding part, and to substrate processing apparatuses in general that use this technique to process substrates. [Explanation of symbols]

[0056] 2...Board holding part 3...Centering mechanism 4...Processing liquid supply mechanism 9...Control unit 10...Substrate processing device 21...Spin base 21C...Center (of the spin base) 23...Rotation drive unit 24...Suction pump (suction part) 31...First contact member 32...Second contact member 33...Third contact member 35...Single moving part 36...Multi-mobile unit 362...Motor (drive unit) 363...Linear guide 363a... Rail (slide member) 363b...Block (guide member) 364...Multi-support part 364a...Slide base 364b...Multi-support member 364b1...End (one end of multi-support part) 364b2...End (other end of multi-support part) 365...Power transmission section 365a... Pinion gear (first power transmission member) 365b...Rack gear (second power transmission member) 365c...dummy parts AE…Allowable eccentricity dLE...(difference in linear expansion coefficient) dTM...(Ambient temperature) change S...Substrate SC: Center (of the board) VS...Vertical imaginary plane X…(Level 1) Direction Y…(Second Horizontal) Direction

Claims

1. a first contact member that can contact an end surface of a disk-shaped substrate placed in a horizontal position on the upper surface of the substrate holding part; a single moving unit that moves the first contact member in a first horizontal direction; a second contact member and a third contact member that can contact the end surface of the substrate from the opposite side of the first contact member across the substrate holding portion; a multi-movement unit that moves the second contact member and the third contact member integrally in the first horizontal direction in a state in which the second contact member and the third contact member, together with the first contact member, surround the center of the substrate holding unit in a plan view from vertically above; a control unit that controls the single movement unit and the multi-movement unit so that the first contact member, the second contact member, and the third contact member sandwich the substrate in the first horizontal direction and position the substrate on the substrate holding unit so that the center of the substrate coincides with the center of the substrate holding unit, The multi-movement unit includes: a multi-support portion that integrally supports the second contact member and the third contact member; a guide member extending in the first horizontal direction; a slide member attached to the multi-support portion and slidable in the first horizontal direction relative to the guide member fixedly disposed at a predetermined position; a driving unit that generates a driving force for moving the multi-support unit in the first horizontal direction; a power transmission unit that transmits the driving force to the multi-support unit; and When the amount of eccentricity of the substrate relative to the substrate holder that is allowable for a change in ambient temperature dTM is defined as the allowable amount of eccentricity AE, The multi-support portion and the slide member have a linear expansion coefficient difference dLE that satisfies the following inequality: dLE<AE / (0.8597×dTM) A centering device characterized in that it is made of a material that satisfies the above.

2. 2. The centering device according to claim 1, The multi-support portion is a horizontal support member extending in a second horizontal direction perpendicular to the first horizontal direction, the horizontal support member supporting the second contact member at one end in the second horizontal direction and the third contact member at the other end; a hanging member hanging downward from the horizontal support member; and the slide member is connected to a side surface of the hanging member; The power transmission unit is disposed below the slide member.

3. 2. The centering device according to claim 1, The multi-support portion is stacked and connected to the upper surface of the slide member.

4. 4. The centering device according to claim 3, The centering device, wherein the multi-support portion and the slide member have shapes that are plane-symmetrical with respect to a vertical imaginary plane that includes the center of the substrate holding portion and is parallel to the first horizontal direction.

5. 5. The centering device according to claim 1, wherein: A centering device, wherein the multi-support portion and the slide member are made of the same material.

6. 6. The centering device according to claim 5, The centering device, wherein the multi-support portion and the slide member are both made of stainless steel.

7. 5. The centering device according to claim 1, wherein: The centering device, wherein the multi-support portion and the slide member are made of aluminum and stainless steel, respectively.

8. a first contact member that can contact an end surface of a disk-shaped substrate placed in a horizontal position on the upper surface of the substrate holding part; a single moving unit that moves the first contact member in a first horizontal direction; a second contact member and a third contact member that can contact the end surface of the substrate from the opposite side of the first contact member across the substrate holding portion; a multi-movement unit that moves the second contact member and the third contact member integrally in the first horizontal direction in a state in which the second contact member and the third contact member, together with the first contact member, surround the center of the substrate holding unit in a plan view from vertically above; a control unit that controls the single movement unit and the multi-movement unit so that the first contact member, the second contact member, and the third contact member sandwich the substrate in the first horizontal direction and position the substrate on the substrate holding unit so that the center of the substrate coincides with the center of the substrate holding unit, The multi-movement unit includes: a multi-support portion that integrally supports the second contact member and the third contact member; a guide member extending in the first horizontal direction; a slide member attached to the guide member, the slide member being slidable in the first horizontal direction relative to the guide member, the guide member being fixedly disposed at a predetermined position, with the multi-support portion stacked and connected on the upper surface of the slide member; a driving unit that generates a driving force for moving the multi-support unit in the first horizontal direction; a power transmission unit that transmits the driving force to the multi-support unit, The centering device, wherein the multi-support portion and the slide member have shapes that are plane-symmetrical with respect to a vertical imaginary plane that includes the center of the substrate holding portion and is parallel to the first horizontal direction.

9. 9. The centering device according to claim 4 or 8, The power transmission unit includes a first power transmission member attached to the drive unit, a second power transmission member attached to the multi-support unit and receiving the driving force from the first power transmission member, and a dummy part of the second power transmission member attached to the multi-support unit so as to be plane-symmetrical to the second power transmission member with respect to the vertical imaginary plane.

10. a substrate holder having an upper surface for supporting a substrate in a horizontal position; a centering device according to claim 1, 2, 3, 4 or 8; a suction unit that evacuates the space between the substrate positioned by the centering device and the substrate holder, thereby suction-holding the substrate on the substrate holder; a rotation drive unit that rotates the substrate holder, which suction-holds the substrate, around a center of the substrate holder; 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 holding unit integrally with the substrate holding unit; A substrate processing apparatus comprising:

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