Centering device

Abstract

With excellent throughput, the center of the disc-shaped substrate placed on the upper surface of the substrate support is aligned with the center of the substrate support. [Solution] This invention comprises a first contact member, a second contact member, and a third contact member. The first contact member is capable of contacting the end face of a disc-shaped substrate placed horizontally on the upper surface of the substrate support. The second and third contact members are supported integrally by a slider, surrounding the center of the first contact member and the substrate support when viewed from a vertically upward plane, and are capable of moving in the opposite horizontal direction to the horizontal direction. The movement of the first contact member in the horizontal direction and the movement of the second and third contact members in the opposite horizontal direction cause the first, second, and third contact members to clamp the substrate, completing the positioning of the substrate on the substrate support. As a result, the center of the substrate coincides with the center of the substrate support, completing the centering process.

Description

Technical Field

[0001] The present invention relates to a centering device that aligns the center of a disk-shaped substrate placed on the upper surface of a substrate support portion with the center of the substrate support portion.

Background Art

[0002] There is known a substrate processing apparatus that supplies a processing liquid to the peripheral portion of a substrate while rotating the substrate such as a semiconductor wafer to perform chemical liquid treatment, cleaning treatment, or the like. For example, in the apparatus described in Patent Document 1, the substrate is adsorbed and held while being supported from below by a spin chuck (corresponding to an example of the "substrate support portion" of the present invention). At this time, if the center of the spin chuck and the center of the substrate are displaced, the processing quality will deteriorate. Therefore, in the above apparatus, before processing the substrate, a so-called centering process is performed to reduce the amount of eccentricity of the substrate with respect to the spin chuck

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above conventional apparatus, the centering process is performed in two steps. First, the amount of eccentricity of the substrate with respect to the spin chuck is measured. Next, the substrate on the spin chuck is horizontally pushed by a pusher, so that the center of the substrate moves toward the center (rotation axis) of the spin chuck. Therefore, there is room for improvement in terms of throughput.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a centering device that can align the center of a disk-shaped substrate placed on the upper surface of a substrate support portion with the center of the substrate support portion with excellent throughput. [Means for solving the problem]

[0006] One aspect of this invention is a centering device comprising: a first contact member capable of contacting the end face of a disc-shaped substrate placed horizontally on the upper surface of a substrate support; a single moving part for moving the first contact member in the horizontal direction; a second contact member and a third contact member capable of contacting the end face of the substrate from the opposite side of the first contact member across the substrate support; a multi-moving part for integrally moving the second contact member and the third contact member in the reverse horizontal direction opposite to the horizontal direction; and the movement of the first contact member in the horizontal direction and the movement of the second contact member and the third contact member in the reverse horizontal direction, thereby moving the first contact member and the second contact member The system includes a control unit that controls a single-moving unit and a multi-moving unit so that the material and the third contact member sandwich the substrate and align the center of the substrate with the center of the substrate support unit to complete the positioning of the substrate on the substrate support unit, wherein the multi-moving unit is characterized by having a slider that is movable in the reverse horizontal direction while integrally supporting the second contact member and the third contact member in a plan view from vertically above, with the second contact member and the third contact member surrounding the center of the first contact member and the center of the substrate support unit, and a drive unit that generates a driving force to move the slider in the reverse horizontal direction.

[0007] In this configuration, a first contact member is provided on the upper surface of the substrate support portion, which is capable of contacting the end face of a disc-shaped substrate placed horizontally on the substrate support portion. Furthermore, the second and third contact members are supported integrally by a slider, surrounding the center of the first contact member and the substrate support portion in a plan view from vertically above, and are movable in the inverse horizontal direction opposite to the horizontal direction. As the first contact member moves horizontally and the second and third contact members move in the inverse horizontal direction, the first, second, and third contact members clamp the substrate, completing the positioning of the substrate on the substrate support portion, and the center of the substrate coincides with the center of the substrate support portion. [Effects of the Invention]

[0008] As described above, according to the present invention, the first contact member, the second contact member, and the third contact member clamp the substrate by moving the first contact member horizontally and moving the second and third contact members in the reverse horizontal direction while being integrally supported by the slider. As a result, once the positioning of the substrate on the substrate support is complete, the center of the disc-shaped substrate placed on the upper surface of the substrate support can be aligned with the center of the substrate support, enabling substrate centering processing with excellent throughput. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows a substrate processing system equipped with one embodiment of a substrate processing apparatus incorporating a centering device according to the present invention. [Figure 2] This diagram schematically shows the configuration of one embodiment of a substrate processing apparatus. [Figure 3] This is a perspective view showing the configuration of the substrate holding section and centering mechanism of a substrate processing apparatus. [Figure 4] This diagram schematically illustrates the operation of the centering mechanism. [Figure 5] This graph shows the variation in load torque with respect to the change in distance from the base center to the protruding portion in the first embodiment. [Figure 6] This figure schematically shows the configuration of a second embodiment of the centering device according to the present invention. [Figure 7] This figure schematically shows the configuration of a third embodiment of the centering device according to the present invention. [Figure 8] This graph shows the change in the amount of movement when the distance from the base center to the protruding part is changed in the third embodiment. [Modes for carrying out the invention]

[0010] Figure 1 shows a substrate processing system equipped with one embodiment of a substrate processing apparatus incorporating a centering device according to the present invention. The substrate processing system 100 comprises 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 comprises a container holding unit 121 that can hold multiple containers C for housing substrates S (such as FOUP (Front Opening UnifiedPod), SMIF (Standard Mechanical Interface) pod, OC (Open Cassette), etc., which house multiple substrates S in a sealed state), and an indexer robot 122 for accessing the containers C held by the container holding unit 121 to remove unprocessed substrates S from the containers C or to store processed substrates S in the containers C. Each container C houses multiple substrates S in a nearly horizontal position.

[0011] The indexer robot 122 comprises a base portion 122a fixed to the device housing, a multi-joint arm 122b rotatably mounted on the base portion 122a around a vertical axis, and a hand 122c attached to the tip of the multi-joint arm 122b. The hand 122c is structured to hold a substrate S placed on its upper surface. Since indexer robots having such a multi-joint arm and a hand for holding a substrate are well known, a detailed explanation will be omitted.

[0012] The substrate processing unit 110 comprises a substrate transport robot 111 positioned approximately in the center in a plan view, and a plurality of processing units 1 arranged to surround the substrate transport robot 111. Specifically, the plurality of processing units 1 are arranged facing the space in which the substrate transport robot 111 is positioned. The substrate transport robot 111 randomly accesses these processing units 1 to receive the substrate S. Meanwhile, each processing unit 1 performs predetermined processing 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.

[0013] Figure 2 is a schematic diagram showing the configuration of one embodiment of the substrate processing apparatus. Figure 3 is a perspective view showing the configuration of the substrate holding section and the centering mechanism of the substrate processing apparatus. Figure 4 is a schematic diagram showing the operation of the centering mechanism. The substrate processing apparatus 10 is an apparatus that performs bevel etching as an example of the "processing" of the present invention, and supplies processing liquid to the peripheral edge of the upper surface of the substrate S in the processing chamber. For this purpose, the substrate processing apparatus 10 is equipped with a substrate holding section 2, a centering mechanism 3 which is the main component of the centering apparatus according to the present invention, and a processing liquid supply mechanism 4. These operations are controlled by a control unit 9 which controls the entire apparatus.

[0014] The substrate holder 2 is equipped with a spin base 21, which is a disc-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 lower surface, so that its upper surface 211 is horizontal. The rotation support shaft 22 is rotatably supported by a rotation drive unit 23. The rotation drive unit 23 has a built-in rotary motor 231, which rotates in response to control commands from the control unit 9. Receiving this rotational driving force, the spin base 21 rotates around a vertical axis AX (dotted line) that passes through the center 21C of the spin base 21 and extends vertically. In Figure 2, the up and down direction is the vertical direction. Also, the plane perpendicular to the plane of Figure 2 is the horizontal plane. To clarify the directional relationships in Figures 2 and beyond, a coordinate system in which the Z axis is the vertical direction and the XY plane is the horizontal plane is appropriately attached.

[0015] The upper surface 211 of the spin base 21 has a size capable of supporting the substrate S, and the substrate S can be placed on the upper surface 211 of the spin base 21. Although not shown in the figure, a plurality of suction holes, suction grooves, etc. are provided on this upper surface 211. These suction holes and the like are connected to the suction pump 24 via the suction pipe 241. When the suction pump 24 operates according to the control command from the control unit 9, a suction force is applied from the suction pump 24 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 adsorbed and held by the spin base 21. The substrate S thus adsorbed and held is rotated around the vertical axis AX together with the rotation of the spin base 21. Therefore, when the center SC of the substrate S does not coincide with the center 21C of the spin base 21, that is, when the substrate S is eccentric, it causes a deterioration in the quality of the bevel etching process.

[0016] Therefore, in the present embodiment, a centering mechanism 3, which is an embodiment of the centering device of the present invention, is provided. The centering mechanism 3 executes a centering process while the suction by the suction pump 24 is stopped (that is, while the substrate S can move horizontally on the upper surface 211 of the spin base 21). By this centering process, the above eccentricity is eliminated, 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.

[0017] In order to perform a bevel etching process on the substrate S that has undergone the centering process, a processing liquid supply mechanism 4 is provided. The processing liquid supply mechanism 4 includes a processing liquid nozzle 41, a nozzle moving unit 42 that moves the processing liquid nozzle 41, and a processing liquid supply unit 43 that supplies the processing liquid to the processing liquid nozzle 41. The nozzle moving unit 42 moves the processing liquid nozzle 4 from a retracted position where the processing liquid nozzle 41 is retracted from above the substrate S to the side as shown by the solid line in FIG. 2 to a processing position above the peripheral edge of the substrate S as shown by the dotted line in the same figure.

[0018] The processing liquid nozzle 41 is connected to the processing liquid supply unit 43. When an appropriate processing liquid is fed from the processing liquid supply unit 43 to the processing liquid nozzle 41 positioned at the processing position, the processing liquid is discharged from the processing liquid nozzle 41 to the peripheral edge of the rotating substrate S. Thereby, bevel etching processing with the processing liquid is executed on the entire peripheral edge of the substrate S.

[0019] Although not shown in FIG. 2, a splash guard portion is provided so as to surround the substrate holding portion 2 from the side. The splash guard portion collects droplets of the processing liquid thrown off from the substrate S during the bevel etching process, and effectively prevents the droplets from scattering around the apparatus.

[0020] Next, the configuration of the centering mechanism 3 will be described while referring to FIGS. 2 to 4. The centering mechanism 3 has a 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 includes an abutting member 31 disposed on the X2 direction (right hand direction in the figure) side with respect to the center 21C of the spin base 21 in the X direction, and abutting members 32 and 33 disposed on the X1 direction (left hand direction in the figure) side. Further, the centering mechanism 3 has a moving mechanism 34 for moving the abutting members 31 to 33 in the horizontal direction.

[0021] The moving mechanism 34 includes a single moving portion 35 for moving the abutting member 31, and a multi moving portion 36 for moving the abutting members 32 and 33 together. The single moving portion 35 is disposed on the X2 direction side with respect to the center 21C of the spin base 21, while the multi moving portion 36 is disposed on the X1 direction side.

[0022] The single-moving unit 35 comprises a fixed base 351, a rotary motor 352, a power transmission unit 353, and a slider 354. The rotary motor 352 is mounted on the fixed base 351, and the power transmission unit 353 and the slider 354 are stacked on the fixed base 351 in that order. The rotary motor 352 is a drive source for moving the contact member 31 in the X direction. When the rotary motor 352 operates in response to a control command from the control unit 9, the rotating shaft (not shown) rotates. This rotating shaft extends from the top 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, for example, by 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 moves in the X direction as the slider 354 moves.

[0023] The multi-movement unit 36 ​​is basically configured the same as the single-movement unit 35, except that the structure of the slider 364 is slightly different. That is, the multi-movement unit 36 ​​applies 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, causing the slider 364 to move in the X direction. The upper part of the slider 364 has two arms 364a and 364b extending in the X2 direction, spaced apart from each other in the Y direction, forming a roughly C shape when viewed from above. Contact members 32 and 33 are attached to the X2 direction ends of the arms 364a and 364b, respectively. Therefore, when the rotary motor 362 operates 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 amount of rotation of the rotary motor 362, similar to the single-movement unit 35. As a result, the contact members 32 and 33 attached to the slider 364 move in the X direction along with the movement of the slider 364.

[0024] In each of the contact members 31 to 33, the end facing the substrate S is beak-shaped. In other words, the protruding portion (tip) of the contact members 31 to 33 has a sharp shape. Therefore, the contact members 31 to 33 can make point contact with the side surface of the substrate S supported by the upper surface 211 of the spin base 21. When the contact member 31 is moved in the X1 direction by the single moving portion 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. Thus, in this embodiment, the direction of movement D1 of the contact member 31 for contacting the substrate S is the X1 direction, which corresponds to the "first horizontal direction" of the present invention. After contact, the contact member 31 moves further in the D1 direction, pressing the substrate S in the X1 direction while moving horizontally in the X1 direction on the upper surface 211 of the spin base 21. Thus, in this embodiment, to aid in understanding the invention, a virtual 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 "virtual line" of the present invention. The following description of the configuration of the centering mechanism 3 will continue, making appropriate use of the virtual line VL.

[0025] The movement of the contact members 32 and 33 by the multi-movement unit 36 ​​differs in part from that of the contact member 31. This is because, in the horizontal plane, the contact members 32 and 33 are arranged symmetrically with respect to the imaginary line VL, and are moved in the X direction while maintaining that arrangement. More specifically, as shown in column (a) of Figure 4, the contact member 32 is positioned a predetermined distance W (however, shorter than the radius rs of the substrate S) away from the imaginary line VL in the Y2 direction. On the other hand, the contact member 33 is positioned on the opposite side of the imaginary line VL from the contact member 32, i.e., in the Y1 direction, by the same distance W as the contact member 32. Therefore, when the contact members 32 and 33 are moved in the X2 direction by the multi-movement unit 36, the protruding portion 321 of the contact member 32 comes into contact with the substrate side on the Y2 direction side of the imaginary line VL, and the protruding portion 331 of the contact member 33 comes into contact with the substrate side on the Y1 direction side of the imaginary line VL. Thus, in this embodiment, the movement direction D2 of the contact member 32 for contacting the substrate S is in the X2 direction, which corresponds to the "second horizontal direction" of the present invention. Similarly, the movement direction D3 of the contact member 33 for contacting the substrate S is also in the X2 direction, which corresponds to the "third horizontal direction" of the present invention. Therefore, in order to move the protruding parts 311, 321, and 331 while maintaining the same distance from the center 21C of the spin base 21 to each protruding part 311, 321, and 331, it is necessary to make the amount of movement per unit time different for the contact member 31 and the contact members 32 and 33. This point will be described in detail with reference to Figure 4, and a centering process using the above movement method will be explained.

[0026] In order to place the substrate S on the upper surface 211 of the spin base 21, it is desirable that the protruding portions 311, 321, and 331 be positioned at a reference position, taking into account at least the maximum 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 need to be at a distance of 150.1 mm or more 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 column (a) of Figure 4, the reference circle is a circle (dotted line) with a radius of reference distance r0 centered at the center 21C of the spin base 21.

[0027] Next, we 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 positioning 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 positioning 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 positioning the protruding portion 331 on the reference circle corresponds to the "third reference position" of the present invention.

[0028] Here, we consider the case where contact members 31 to 33 are initially positioned at the first, second, and third reference positions, respectively, and then contact member 31 is moved a small amount Δd1 toward the substrate S in the D1 direction (X1 direction). If contact members 32 and 33 are moved a small amount by the same distance in the D2 direction (X2 direction) in response, the distances from the center 21C of the spin base 21 to the protruding parts 311, 321, and 331 will be uneven. Therefore, if the small movements of contact members 31 to 33 are repeated while maintaining a uniform amount of movement per unit time, the center SC of the substrate S will never coincide with the center 21C of the spin base 21.

[0029] In contrast, as shown in column (b) of Figure 4, the distance Δd2 (corresponding to the "second movement amount" of the present invention) for moving the contact member 32 by a small amount and the distance Δd3 (corresponding to the "third movement amount" of the present invention) for moving the contact member 33 by a small amount are 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 part 321 before minute movement. θ1: The angle between the line connecting the center 21C and the protruding part 321 and the imaginary line VL before the small movement. r2: Distance from the center 21C to the protruding part 321 after a small movement. θ2: The angle between the line connecting the center 21C and the protruding part 321 and the imaginary line VL after a small movement. W: Distance from virtual line VL to contact member 32, This can be set. In this case, even after a small movement, the distance from the center 21C of the spin base 21 to the protruding parts 311, 321, and 331 remains the same. By repeating such small movements, the contact members 31 to 33 approach the substrate S while maintaining the same distance from the center 21C of the spin base 21 to the protruding parts 311, 321, and 331. Then, for example, if eccentricity occurs as shown in Figure 4, during the repetition of the above small movements, the contact member 31 first contacts the substrate S, moving the substrate S in the D1 direction (see column (c) in Figure 4). Subsequently, the contact member 32 contacts the substrate S, which is being pushed by the contact member 31, and moves it horizontally. Then, as shown in column (d) of Figure 4, when the distance from the center 21C of the spin base 21 to the protruding parts 311, 321, and 331 becomes equal to the radius of the substrate S, the last contact member 33 also contacts the substrate S. In this way, the substrate S is sandwiched between the contact members 31-33, stopping its movement, and the center SC of the substrate S coincides with the center 21C of the spin base 21. In this manner, the centering process of the substrate S can be performed.

[0030] In this embodiment having the centering mechanism 3 described above, the control unit 9 controls each part of the substrate processing apparatus 10 to perform the centering process and the subsequent bevel etching process. The control unit 9 is equipped with an arithmetic processing unit 91 consisting of a computer having a CPU (= Central Processing Unit) and RAM (= Random Access Memory), a storage unit 92 such as a hard disk drive, and a motor control unit 93.

[0031] The arithmetic processing unit 91 reads the centering program and bevel etching program stored in the memory unit 92 as appropriate, loads them into RAM (not shown), and performs the centering and bevel etching processes shown in Figure 4. In particular, when performing the centering process, the arithmetic processing unit 91 calculates the first to third movement amounts Δd1 to Δd3 and controls the rotating motors 352 and 362 of the moving 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 moving section 35 from the motor current value supplied to the rotating motor 352 and the load torque at the multi-moving section 36 from the motor current value supplied to the rotating motor 362. Here, as the distance from the center 21C of the spin base 21 to the protruding sections 311, 321, and 331 (distance from the base center to the protruding sections) changes while the minute movement is repeated, the load torque fluctuates as shown in Figure 5, for example. As shown in the figure, when the above distance matches the radius rs of the substrate S, that is, when the contact members 31-33 grip the substrate S, the load torque increases rapidly in the single-movement section 35 and the multi-movement section 36 almost simultaneously. Therefore, the calculation processing unit 91 determines that the centering process is complete when the load torque exceeds a threshold and stops the movement of the contact members 31-33. In this embodiment, the fluctuation of the load torque is monitored for all motors 352 and 362, but the timing of stopping the movement of the contact members 31-33 may be determined by monitoring only one motor. It goes without saying that the load torque may also be calculated based on something other than the motor current value.

[0032] 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 aligned with the center 21C of the spin base 21. In this way, the centering process is performed solely by the repeated minute movements of the contact members 31 to 33, enabling centering with excellent throughput.

[0033] Furthermore, the completion of the centering process is confirmed based on the load torque fluctuation, and the movement of the contact members 31-33 is immediately stopped. Therefore, the centering process can be completed at an appropriate timing without damaging the substrate S. This is also true in the embodiments described later.

[0034] 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," "second contact member," and "third contact member" of the present invention, respectively. The control unit 9 corresponds to an example of the "control unit" of the present invention. The spin base 21 and the center 21C correspond to examples of the "substrate support part" and the "center of the substrate support part" of the present invention, respectively. The suction pump 24 corresponds to an example of the "suction part" of the present invention.

[0035] In the first embodiment described above, the multi-movement unit 36 ​​moves the two contact members 32 and 33 in the D2 direction (X2 direction) and the D3 direction (X2 direction), respectively. However, instead of the multi-movement unit 36, a single-movement unit for contact member 32 and a single-movement unit for contact member 33, configured similarly to the single-movement unit 35, may be provided. In this case, the single-movement units provided for each of 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.

[0036] Furthermore, when a single movable part for contact member 32 and a single movable part for contact member 33 are provided in this manner, there is no necessity to unify both the D2 direction and the D3 direction with the X2 direction, and at least one of the D2 direction and the D3 direction may be changed from the X2 direction (second embodiment).

[0037] Figure 6 is a schematic diagram showing the configuration of a second embodiment of the 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 contact member 32 and a single-movement unit 38 for the contact member 33, which are configured similarly to the single-movement unit 35, are provided, and both the D2 direction and the D3 direction 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 Figure 4 and the consideration of the second and third movement amounts based thereon. The other configurations and operations are basically the same as in the first embodiment.

[0038] In this second embodiment, 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. As a result, the center SC of the substrate S coincides with the center 21C of the spin base 21. Therefore, the centering process is performed solely by the repeated minute movements of the contact members 31 to 33, enabling centering with excellent throughput.

[0039] Figure 7 is a schematic diagram showing the configuration of a third embodiment of the centering device according to the present invention. The main difference between the third embodiment and the first embodiment is the shape of the protruding portions 311, 321, and 331 of each contact member 31 to 33. In other words, in the first embodiment, the protruding portions 311, 321, and 331 have a sharp shape. As a result, wear due to contact with the substrate S is relatively severe, raising concerns about an increase in the frequency of replacement. Therefore, as shown in Figure 7, the protruding portions 311, 321, and 331 may be finished in a semi-disc shape. However, in the third embodiment, the contact position of the protruding portion 321 with respect to the substrate S is displaced according to 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 amounts of movement in the third embodiment cannot be calculated by directly applying the contents of columns (a) and (b) in Figure 4 and the consideration of the second and third amounts of movement based thereon.

[0040] Therefore, in the third embodiment, the reference distance r0 was set to 150.25 mm (= 300.5 mm / 2), and the diameters of the protruding parts 311, 321, and 331 were set to 20 mm. Plan views were then created for distances of 300.5 mm, 300.2 mm, 300.1 mm, 300 mm, 299.9 mm, 299.8 mm, and 299.5 mm, which are twice the distance (from the center 21C of the spin base 21 to the protruding parts 311, 321, and 331). In Figure 7, the plan view for a distance of 300.5 mm (see column (a) in the same figure) and the plan view for a distance of 300.2 mm (see column (b) in the same figure) are shown, while other plan views are omitted. Then, from those plan views, the amount of movement of contact member 31 and contact members 32 and 33 required to gradually reduce the above distance from 300.5 mm was determined. Figure 8 summarizes the results. For reference, the same figure also shows a graph illustrating the variation in the amount of movement of contact members 32 and 33 obtained in the first embodiment.

[0041] Figure 8 is a graph showing the change in the amount of movement when the distance from the base center to the protruding portion is changed 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 (the distance from the base center to the protruding portion) while keeping the distance the same, it is necessary to change the amount of movement as appropriate. Furthermore, it can be seen from the graph that the manner in which the amount of movement is changed can be approximated by a linear function. Therefore, in the third embodiment, the above linear function is stored in the memory unit 92 in advance. On the other hand, when performing centering processing, the arithmetic processing unit 91 reads the linear function from the memory unit 92. Then, during centering processing, the arithmetic 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, centering processing by the contact members 31 to 33 can be performed well while keeping the distance from the center 21C of the spin base 21 to the protruding portions 311, 321, and 331 the same. As a result, the same effects as in the first embodiment can be obtained.

[0042] Furthermore, in the third embodiment, since the protruding portions 311, 321, and 331 have a semi-disc shape, they are less prone to wear than the first embodiment, which has a sharp shape. Therefore, the frequency of replacement of the contact members 31 to 33 can be reduced, thereby reducing the burden on the operator and running costs.

[0043] It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be made to those described above without departing from the spirit of the invention. For example, in the above embodiments, the completion of the clamping of the substrate S by the contact members 31 to 33, i.e., the completion of the centering process, is detected based on load torque fluctuations, but the above detection may be performed by other methods. For example, sensors such as load cells or strain gauges may be provided on the single moving parts 35, 37, 38 and the multi-moving part 36, and the sensors may be configured to detect stress or strain when the substrate S is clamped by the contact members 31 to 33 and output a detection signal. In this case, the control unit 9 confirms that the substrate S is clamped by the contact members 31 to 33 based on the detection signal from the sensors.

[0044] Furthermore, in the third embodiment described above, the arithmetic 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 summarized in a data table and stored in the storage unit 92.

[0045] Furthermore, in the third embodiment described above, the protruding portions 321 and 331 are finished in a semi-disc shape, but they may also be finished in an inclined shape when viewed from the vertical direction. Thus, a configuration in which the protruding portions 311, 321, and 331 are finished in a semi-disc shape, or in an inclined shape, may also be applied to the second embodiment.

[0046] Furthermore, although the above embodiment applies the present invention to a centering device equipped in a substrate processing apparatus 10 that performs bevel etching, the centering device according to the present invention can be applied to centering devices and centering methods in general that are equipped in a substrate processing apparatus that processes a disc-shaped substrate while rotating it. [Industrial applicability]

[0047] This invention can be applied to a centering technique that aligns the center of a disc-shaped substrate placed on the upper surface of a substrate support with the center of the substrate support, and to substrate processing equipment in general that utilizes this technique for processing substrates. [Explanation of Symbols]

[0048] 3… Centering mechanism 21…Spin base (substrate support part) 21C… (Spin Base) Center 31...First contact member 32...Second contact member 33...Third contact member 34...Movement mechanism 35, 37, 38… Single mobile unit 36…Multi-purpose mobile unit 211…(Spin base) top surface 231,352,362… Rotary motors S... Circuit board SC... (Center of the circuit board)

Claims

1. A first contact member that can contact the end face of a disc-shaped substrate placed horizontally on the upper surface of the substrate support, A single moving part that moves the first contact member in the horizontal direction, A second contact member and a third contact member are provided, which are capable of contacting the end face of the substrate from the opposite side of the first contact member, with the substrate support portion in between. A multi-movement unit that moves the second contact member and the third contact member integrally in the reverse horizontal direction opposite to the aforementioned horizontal direction, The system includes a control unit that controls the single-movement unit and the multi-movement unit, such that the movement of the first contact member in the horizontal direction and the movement of the second and third contact members in the reverse horizontal direction cause the first contact member, the second contact member, and the third contact member to sandwich the substrate, thereby aligning the center of the substrate with the center of the substrate support unit and completing the positioning of the substrate on the substrate support unit. The multi-moving unit is In a plan view from vertically above, the second contact member and the third contact member surround the first contact member and the center of the substrate support portion, and the slider is movable in the reverse horizontal direction while integrally supporting the second contact member and the third contact member. A drive unit that generates a driving force to move the slider in the reverse horizontal direction, A centering device characterized by having [a certain feature].

2. A centering device according to claim 1, The upper part of the slider is provided with a first arm and a second arm that extend in the inverse horizontal direction, spaced apart from each other in a direction perpendicular to the inverse horizontal direction, and has a substantially C-shape when viewed from above in a plan view. A centering device in which the second contact member is attached to the first arm and the third contact member is attached to the second arm.

3. A centering device according to claim 1 or 2, A centering device wherein the slider includes the center of the substrate holding portion and has a shape that is symmetrical with respect to a vertical virtual plane parallel to the horizontal direction and the inverse horizontal direction.

4. A centering device according to claim 3, The multi-movement unit is positioned directly below the slider and further comprises a power transmission unit that transmits the driving force generated by the drive unit to the slider, in a centering device.

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