Centering device, centering method, and substrate processing apparatus

Abstract

To provide a centering technology with excellent design freedom and a substrate processing apparatus using the centering technology.SOLUTION: The present invention surrounds a substrate at the top of a substrate support by a first contacting member positioned in the first reference position, a second contacting member positioned in the second reference position, and a third contacting member positioned in the third reference position, in the horizontal plane. Then, through repetition of minute movement of these three contacting members, they gradually approach the substrate while maintaining the same distance from the center of the substrate support. The substrate is then sandwiched between these three contacting members to align the center of the substrate with the center of the substrate support. Prior to this series of centering, the substrate orientation is adjusted so that the eccentric direction is parallel to the virtual line.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] There is known a substrate processing apparatus that performs chemical treatment, cleaning treatment, or the like by supplying a treatment liquid to the peripheral edge of a substrate such as a semiconductor wafer while rotating the substrate. For example, in the apparatus described in Patent Document 1, a substrate is suction-held while being supported from below by a spin chuck (corresponding to an example of the "substrate support portion" in the present invention). At this time, if the center of the spin chuck is misaligned with the center of the substrate, this leads to deterioration in processing quality. Therefore, it is desirable to equip the above apparatus with a centering device.

[0003] The centering device performs so-called centering processing to reduce the amount of eccentricity of the substrate with respect to the spin chuck. As the centering device, for example, as described in Patent Document 2, a device that reciprocates moving bodies respectively on respective axes radially extending in a direction perpendicular to the central axis of the spin chuck can be employed. [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Unexamined Patent Publication No. 2022-146507 [Patent Document 2] Japanese Unexamined Patent Publication No. 10-209249 [Summary of the Invention] [Problems to be Solved by the Invention]

[0005] In the above-mentioned centering device, it is necessary to move at least three or more moving parts back and forth along their axes, which has resulted in a problem of large device size. Therefore, the inventors of this application have developed a centering device having three contact members, as shown in Figure 3, which will be explained later, in order to minimize the number of moving parts and reduce the size of the device. The three contact members are

[0006] (1) A first contact member that is movable in a first horizontal direction toward the center of the substrate support portion, from a first reference position located at a reference distance from the center of the substrate support portion that is longer than the radius of the substrate in a horizontal plane, and

[0007] (2) In a horizontal plane, the second contact member is located opposite the first contact member with respect to the center of the substrate support portion, deviates from a virtual line extending in the first horizontal direction from the center of the substrate support portion, and is located a reference distance from the center of the substrate support portion, and is movable in a second horizontal direction that is different from the direction toward the center of the substrate support portion from the second reference position and moves toward the substrate, and

[0008] (3) A third contact member that is movable in a third horizontal direction that is different from the direction toward the center of the substrate support and toward the substrate, located in a horizontal plane, on the opposite side of the first contact member with respect to the center of the substrate support and on the opposite side of the second contact member with respect to the imaginary line, and located a reference distance from the center of the substrate support, In this centering device, the first, second, and third contact members are repeatedly moved by a first, second, and third amount, respectively, so that the distance of each member from the center of the substrate support portion is kept the same. The centering process is completed by sandwiching the substrate between the first, second, and third contact members.

[0009] However, the movement of the substrate moved by the contact members includes a movement component in the first horizontal direction (the X direction, which will be explained later) and a movement component in the horizontal direction perpendicular to the first horizontal direction (the Y direction, which will be explained later). In particular, as the eccentricity direction of the substrate deviates from the imaginary line extending from the center of the spin chuck in the first horizontal direction (indicated by VL in Figures 3, 5, 6, and 8, which will be explained later), the latter movement component increases. Therefore, constraints arise such as the need to set the arrangement of the second and third contact members taking this into consideration, and the need to use a relatively high-power movement mechanism to move the second and third contact members. As a result, a new problem arises in which the design freedom of the centering device is greatly limited.

[0010] This invention has been made in view of the above-mentioned problems, and aims to provide a centering technology with excellent design flexibility, and a substrate processing apparatus using said centering technology. [Means for solving the problem]

[0011] A first aspect of this invention is a centering device for positioning a disc-shaped substrate on a substrate support so that the center of the substrate placed horizontally on the upper surface of the substrate support coincides with the center of the substrate support, comprising: a first contact member that is movable in a first horizontal direction toward the center of the substrate support from a first reference position located in a horizontal plane at a reference distance longer than the radius of the substrate from the center of the substrate support; and a second contact member that, in a horizontal plane, deviates from a virtual line extending in a first horizontal direction from the center of the substrate support on the opposite side of the first contact member relative to the center of the substrate support and supports the substrate A second contact member is movable in a second horizontal direction that is different from the direction toward the center of the substrate support and approaches the substrate, from a second reference position located a reference distance from the center of the support portion, and a third contact member is movable in a third horizontal direction that is different from the direction toward the center of the substrate support portion and approaches the substrate, from a third reference position located in the horizontal plane, opposite to the center of the substrate support portion with respect to the first contact member and opposite to the second contact member with respect to the imaginary line, and located a reference distance from the center of the substrate support portion. The first contact member, the second contact member, and the third contact member are each in the first horizontal direction and the second horizontal direction, respectively. The system comprises a moving mechanism that moves in a directional and a third horizontal direction, a rotation drive unit that rotates a substrate support on which a substrate is placed, a measuring unit that measures the peripheral edge of a substrate placed on the substrate support unit with the first, second, and third contact members spaced apart from the end face of the substrate, and a control unit that performs positioning by controlling the moving mechanism and the rotation drive unit, the control unit having an eccentricity information acquisition unit that determines the eccentricity direction in which the center of the substrate is eccentric from the center of the substrate support unit based on peripheral information regarding the peripheral edge of the substrate measured by the measuring unit, and the rotation drive unit The system is characterized by having a substrate orientation adjustment unit that adjusts the orientation of the substrate so that the eccentricity direction is parallel to the virtual line, and a movement control unit that, while the eccentricity direction is parallel to the virtual line, moves the first contact member, second contact member, and third contact member by a first, second, and third movement amount, respectively, so that the distance of each of them from the center of the substrate support portion is kept the same, until all of the first, second, and third contact members have made contact with the substrate.

[0012] Furthermore, a second aspect of this invention is a centering method for positioning a disc-shaped substrate on a substrate support such that the center of the substrate placed horizontally on the upper surface of the substrate support coincides with the center of the substrate support, wherein (a) a first contact member is positioned in a horizontal plane at a first reference position that is a reference distance from the center of the substrate support that is longer than the radius of the substrate, and the opposite side of the first contact member relative to the center of the substrate support is deviated from a virtual line extending from the first reference position through the center of the substrate support and is a reference distance from the center of the substrate support (b) With the second contact member positioned at a distant second reference position, and the third contact member positioned at a third reference position on the opposite side of the first contact member from the center of the substrate support and on the opposite side of the second contact member from the imaginary line, and a reference distance away from the center of the substrate support, the substrate is placed on the upper surface of the substrate support; and (b) with the substrate placed on the upper surface of the substrate support so as to be able to move horizontally, the first water from the first reference position toward the center of the substrate support is moved such that the distances of the first contact member, the second contact member and the third contact member from the center of the substrate support are kept the same. (a) A step of repeatedly performing minute movements, moving the first contact member in the horizontal direction, moving the second contact member by a second amount in a second horizontal direction that is different from the direction toward the center of the substrate support from the second reference position and is closer to the substrate, and moving the third contact member by a third amount in a third horizontal direction that is different from the direction toward the center of the substrate support from the third reference position and is closer to the substrate; (c) A step of stopping the minute movements when it is confirmed that the substrate is sandwiched between the first contact member, the second contact member and the third contact member during the repetition of minute movements; and (d) Step (a) The process (c) includes a step of adjusting the orientation of the substrate placed on the upper surface of the substrate support before performing the process (c), wherein the process (d) includes (d-1) a step of measuring the peripheral edge of the substrate placed on the upper surface of the substrate support, (d-2) a step of determining the eccentricity direction in which the center of the substrate is eccentric from the center of the substrate support based on peripheral information regarding the peripheral edge of the substrate, and (d-3) a step of adjusting the orientation of the substrate by rotating the substrate support so that the eccentricity direction is parallel to a virtual line extending through the center of the substrate support.

[0013] Furthermore, a third aspect of this invention is a substrate processing apparatus comprising: a substrate support portion having an upper surface for supporting a substrate in a horizontal position; a centering device; a suction portion that exhausts the space between the substrate positioned by the centering device and the substrate support portion to hold the substrate by suction to the substrate support portion; a rotation drive portion that rotates the substrate support portion that holds the substrate by suction around the center of the substrate support portion; and a processing liquid supply mechanism that supplies processing liquid to the peripheral edge of the substrate which is rotated integrally with the substrate support portion around the center of the substrate support portion.

[0014] In this configuration, the substrate is surrounded in the horizontal plane by a first contact member positioned at a first reference position, a second contact member positioned at a second reference position, and a third contact member positioned at a third reference position. These three contact members gradually approach the substrate while maintaining a constant distance from the center of the substrate support through repeated minute movements. In this invention, prior to the start of movement of the contact members, the substrate orientation is adjusted so that the eccentricity direction is parallel to the imaginary line. In other words, the eccentricity of the substrate in the horizontal plane consists only of a component parallel to the imaginary line (corresponding to the X-direction component, which will be explained later), and the horizontal component perpendicular to the eccentricity direction (corresponding to the Y-direction component, which will be explained later) becomes almost zero. Therefore, during the approach movement, the contact members sequentially contact the substrate and push the substrate along the imaginary line. In other words, all of the pushing force is used to move the substrate in the opposite direction to the eccentricity direction, making it possible to position the substrate with a small force. Furthermore, since the substrate does not move in a horizontal direction perpendicular to the eccentric direction during the positioning operation, it becomes possible to reduce the spacing between the second and third contact members in that horizontal direction. As a result, there are fewer constraints on the configuration of the movement mechanism and the arrangement of the second and third contact members. [Effects of the Invention]

[0015] As described above, the present invention makes it possible to perform substrate centering with excellent design flexibility. [Brief explanation of the drawing]

[0016] [Figure 1]It is a plan view showing the schematic configuration of a substrate processing system equipped with a first embodiment of the substrate processing apparatus according to the present invention. [Figure 2] It is a diagram schematically showing the configuration of the first embodiment of the substrate processing apparatus. [Figure 3] It is a perspective view showing the configuration of a substrate holding unit and a centering mechanism of the substrate processing apparatus. [Figure 4] It is a diagram schematically showing the configuration of an abutment member that can be employed in the centering mechanism and the relationship with the notch of a substrate. [Figure 5] It is a diagram schematically showing the operation of the centering mechanism. [Figure 6] It is a diagram schematically showing the positional relationship between the abutment member and the center of a spin base before and after micro-movement. [Figure 7] It is a graph showing the fluctuation of load torque with respect to a change in the distance from the center of the base to the abutment surface in the first embodiment. [Figure 8] It is a flowchart showing the operation of the substrate processing apparatus shown in FIG. 2. [Figure 9] It is a diagram schematically showing the configuration of an abutment member employed in a third embodiment of the centering apparatus according to the present invention and the relationship with the notch of a substrate. [Figure 10] It is a diagram schematically showing how the positional relationship between the abutment member and the notch changes by adjusting the posture of the substrate. [Figure 11] It is a flowchart showing the operation of a fourth embodiment of the centering apparatus according to the present invention. [Figure 12] It is a flowchart showing the operation of a fifth embodiment of the centering apparatus according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Figure 1 is a plan view showing the schematic configuration of a substrate processing system equipped with a first embodiment of the substrate processing apparatus according to the present invention. This does not show the external appearance of the substrate processing system 100, but is a schematic diagram that clearly shows its internal structure by excluding the outer wall panels and some other components of the substrate processing system 100. This substrate processing system 100 is a single-wafer type device that is installed, for example, in a clean room and processes substrates S one by one, on which circuit patterns, etc. (hereinafter referred to as "patterns") are formed only on one main surface. Substrate processing is performed using a processing liquid in a processing unit equipped in the substrate processing system 100. In this specification, of the two main surfaces of the substrate, the pattern-forming surface (one main surface) on which a pattern is formed is referred to as the "front surface," and the other main surface on the opposite side on which no pattern is formed is referred to as the "back surface." Also, the surface facing downwards is referred to as the "bottom surface," and the surface facing upwards is referred to as the "top surface." In this specification, "pattern-forming surface" means a surface on the substrate on which an uneven pattern is formed in an arbitrary area.

[0018] In this embodiment, the "substrate" can be any type of substrate, such as a semiconductor wafer, a glass substrate for a photomask, a glass substrate for a liquid crystal display, a glass substrate for a plasma display, a substrate for a Field Emission Display (FED), a substrate for an optical disk, a substrate for a magnetic disk, or a substrate for a magneto-optical disk. The following explanation will primarily use a substrate processing apparatus used for processing semiconductor wafers as an example, with reference to the drawings, but the method can also be applied to processing the various types of substrates exemplified above.

[0019] As shown in Figure 1, the substrate processing system 100 has a substrate processing area 110 for processing substrates S. An indexer unit 120 is provided adjacent to this substrate processing area 110. The indexer unit 120 has a container holding unit 121 that can hold multiple containers C for housing substrates S (such as FOUP (Front Opening Unified Pod), SMIF (Standard Mechanical Interface) pod, OC (Open Cassette), etc., which house multiple substrates S in a sealed state). The indexer unit 120 also includes 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 and store processed substrates S in the containers C. Each container C contains multiple substrates S in a nearly horizontal position.

[0020] 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.

[0021] In the substrate processing area 110, a mounting table 112 is provided to allow substrates S from the indexer robot 122 to be placed on it. In a plan view, a substrate transport robot 111 is positioned approximately in the center of the substrate processing area 110. Furthermore, multiple processing units 1 are arranged surrounding this substrate transport robot 111. The substrate transport robot 111 randomly accesses these processing units 1 to receive the substrates S. Meanwhile, each processing unit 1 performs predetermined processing on the substrates S. In this embodiment, one of these processing units 1 corresponds to the substrate processing apparatus 10 according to the present invention.

[0022] Figure 2 is a schematic diagram showing the configuration of the first 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 configuration of the contact member that can be used in the centering mechanism and its relationship with the notch on the substrate. Figure 5 is a schematic diagram showing the operation of the centering mechanism. Figure 6 is a schematic diagram showing the positional relationship between the contact member and the center of the spin base before and after minute movement. 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.

[0023] 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 rotation motor 231, which rotates in response to a control command 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.

[0024] The upper surface 211 of the spin base 21 has a width sufficient 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 in the figure, the upper surface 211 is provided with a plurality of suction holes and suction grooves. These suction holes are connected to the suction pump 24 via the suction pipe 241. This suction pump 24 functions as an example of the "suction unit" of the present invention. When this suction pump 24 operates in response to a control command from the control unit 9, a suction force is applied to the spin base 21 from the suction pump 24. 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, held in this adsorbed position, rotates around the vertical axis AX together with the rotation of the spin base 21. Therefore, if the center SC of the substrate S does not coincide with the center 21C of the spin base 21, that is, if the substrate S is eccentric, it will lead to a decrease in the quality of the bevel etching process.

[0025] Therefore, in this embodiment, a centering mechanism 3 is provided, and in cooperation with the control unit 9, functions as a "centering device" according to the present invention. The centering mechanism 3 has a measuring unit 37 that measures the peripheral edge of the substrate S held by adsorption on the spin base 21. As shown in Figure 3, this measuring unit 37 is located on the peripheral edge of the substrate S held by adsorption 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 measuring unit 37 is movable to a retracted position spaced away from the peripheral edge of the substrate S. As the measuring unit 37, for example, an edge detection sensor described in Japanese Patent Application Publication No. 2021-54562 can be used. More specifically, the measuring 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 eccentricity direction (indicated by D5 in Figure 8, which will be explained later), the amount of eccentricity, and the relative position of the notch NT with respect to the eccentricity direction, as the center SC of the substrate S is eccentric 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 information. Since the method for deriving the eccentricity direction, amount of eccentricity, and notch position based on the edge detection signal and continuous images of the peripheral edge is well known, a detailed explanation is omitted here.

[0026] The spin base 21 rotates by an angle corresponding to the eccentricity direction thus acquired, while still holding the substrate S by suction. This adjusts the orientation of the substrate S so that the eccentricity direction coincides with the imaginary line described later. Subsequently, the suction by the suction pump 24 is stopped, meaning that the substrate S becomes capable of horizontal movement on the upper surface 211 of the spin base 21. In this state, the 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 detailed configuration and operation of the centering mechanism 3, including the orientation adjustment described above, will be explained later.

[0027] A processing liquid supply mechanism 4 is provided to perform bevel etching on a substrate S that has undergone centering. 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 processing liquid to the processing liquid nozzle 41. The nozzle moving unit 42 moves the processing liquid nozzle 41 between a retracted position, where it is moved laterally 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.

[0028] The processing liquid nozzle 41 is connected to the processing liquid supply unit 43. When an appropriate amount of 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 discharged from the processing liquid nozzle 41 to the periphery of the rotating substrate S. As a result, bevel etching is performed on the entire periphery of the substrate S using the processing liquid.

[0029] Although not shown in Figure 2, the splash guard is provided so as to surround the substrate holding section 2 from the side. The splash guard collects droplets of the processing liquid that are shaken off the substrate S during the bevel etching process, and effectively prevents these droplets from scattering around the apparatus.

[0030] Next, the configuration of the centering mechanism 3 will be described with reference to Figures 2 to 6. 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 positioned on the X2 direction side (right-hand direction in the figure) with respect to the center 21C of the spin base 21 in the X direction, and contact members 32 and 33 positioned on the X1 direction side (left-hand direction in the figure). The centering mechanism 3 also has a moving mechanism 34 for moving the contact members 31 to 33 in the horizontal direction.

[0031] The moving mechanism 34 includes a single moving section 35 for moving the contact member 31 and a multi-moving section 36 for moving the contact members 32 and 33 together. With respect to the center 21C of the spin base 21, the single moving section 35 is positioned on the X2 direction side, while the multi-moving section 36 is positioned on the X1 direction side.

[0032] 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 this 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.

[0033] 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 vertically 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.

[0034] Each of the contact members 31 to 33 has a contact surface 311 to 331 that can contact the end face Se of the substrate S. With these contact surfaces 311 to 331 facing the end face Se of the substrate S, the contact members 31 to 33 are arranged in the XY plane (horizontal plane) to surround the substrate holding portion 2. The contact surfaces 311 to 331 have a planar shape, and their surface normals point to the vertical axis AX. For example, as shown in column (a) of Figure 4, on the contact surface 321, a linear region 322 that intersects with a virtual horizontal plane containing the substrate S placed on the upper surface of the substrate holding portion 2 functions as a contactable region, and its length L is longer than the arc length Ln of the notch NT that cuts off the circumference of the substrate S. Therefore, during centering, when the contact member 32 is moved toward the end face Se of the substrate S, it contacts the end face Se of the substrate S at one or two points in the linear region 322. In other words, as shown in the figure, when the notch NT is placed on the upper surface of the spin base 21 in a position facing the contact surface 321, the two contact points CP1 and CP2 on the linear region 322 contact the end face Se of the substrate S. On the other hand, in all other cases, one contact point on the linear region 322 contacts the end face Se of the substrate S. The same applies to the contact surfaces 311 and 331. The reason for configuring the contact members 31 to 33 as described above will be explained in detail later with reference to Figure 4.

[0035] When the contact member 31 is moved in the X1 direction by the single moving part 35, the contact surface 311 of the contact member 31 moves toward the center 21C of the spin base 21 and contacts the end face Se 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 horizontally moving it in the X1 direction on the upper surface 211 of the spin base 21. Thus, in this embodiment, in order to aid in understanding the content of 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, 5, and 6. This corresponds to the "virtual line" of the present invention. The explanation of the configuration of the centering mechanism 3 will continue below, making appropriate use of the virtual line VL.

[0036] 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 5, 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 contact surface 321 of the contact member 32 comes into contact with the substrate end face on the Y2 direction side of the imaginary line VL, and the contact surface 331 of the contact member 33 comes into contact with the substrate end face 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 contact surfaces 311, 321, and 331 while maintaining the same distance from the center 21C of the spin base 21 to each contact surface 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 Figures 5 and 6, and a centering process using the above movement method will be explained.

[0037] In order to place the substrate S on the upper surface 211 of the spin base 21, it is desirable that the contact surfaces 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 contact surfaces 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 5, 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.

[0038] Next, we consider the case where the contact members 31 to 33 are positioned so that the contact surfaces 311, 321, and 331 are located on the reference circle, and then the contact surfaces 311, 321, and 331 are moved toward the substrate S. In this case, the position of the contact member 31 for positioning the contact surface 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 contact surface 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 contact surface 331 on the reference circle corresponds to the "third reference position" of the present invention.

[0039] 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 contact surfaces 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.

[0040] In contrast, as shown in column (b) of Figure 5 and in Figure 6, by moving the contact member 31 by a small amount Δd1 in the D1 direction, the contact member 32 is moved by a small amount Δd2 in the D2 direction, and the contact member 33 is moved by a small amount Δd3 (=Δd2) in the D3 direction, thereby moving the contact surfaces 311, 321, and 331 while maintaining the same distance from the center 21C of the spin base 21 to each contact surface 311, 321, and 331.

[0041] Figure 6 schematically shows the positional relationship between the contact member 32 and the center 21C of the spin base 21 before and after a small movement. Figure 6 shows the positional relationship between the contact member 32 and a circle with radius r1 centered at the center 21C of the spin base 21, and the positional relationship between the contact member 32 and a circle with radius r2 centered at the center 21C of the spin base 21. In Figure 6, the contact member 32 before being moved by a second movement amount Δd2 in the D2 direction is shown by a solid line, and the contact member 32 after being moved by a dashed line. Figure 6 shows the contact point 324 between the circle with radius r1 centered at the center 21C of the spin base 21 and the contact member 32, and the contact point 325 between the circle with radius r2 centered at the center 21C of the spin base 21 and the contact member 32.

[0042] As shown in Figure 6, contact point 324 and contact point 325 are located at different positions on the contact member 32. On the other hand, the straight line connecting the center 21C of the spin base 21 and contact point 324 coincides with the straight line connecting the center 21C of the spin base 21 and contact point 325. Furthermore, the angle between the straight line connecting the center 21C of the spin base 21 and contact point 324 and the imaginary line VL is the same as the angle between the straight line connecting the center 21C of the spin base 21 and contact point 325 and the imaginary line VL.

[0043] Therefore, 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-r2) / cosθ=Δd1 / cosθ r1=r0 r² = r¹ - Δd¹ however, r1: Distance from the center 21C to the contact surface 321 before the small movement. θ: The angle between the line connecting the center 21C of the spin base 21 and the contact points 324 and 325, and the imaginary line VL. r2: Distance from the center 21C to the contact surface 321 after 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 contact surfaces 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 contact surfaces 311, 321, and 331. Then, for example, if eccentricity occurs as shown in Figure 5, 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 5). 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 5, when the distance from the center 21C of the spin base 21 to the contact surfaces 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.

[0044] 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 which is composed 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.

[0045] 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 5. 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 contact surfaces 311, 321, and 331 (distance from the base center to the contact surface) changes while the minute movement is repeated, the load torque fluctuates as shown in Figure 7, 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. These points are also true when the contact members 31-33 are moved by separate motors. Furthermore, when the contact members 31-33 are moved by a single motor, the calculation may be based on the load torque or motor current value of that motor.

[0046] To ensure proper centering operation as shown in Figures 5 and 6, it is necessary to improve the positional accuracy of the substrate S in the direction of travel of the contact members 31-33 (X-direction) and the horizontal direction perpendicular to it (Y-direction). In particular, to improve the positional accuracy of the substrate S in the Y-direction, one approach is to widen the distance between the contact members 32 and 33 in the Y-direction. However, this approach inevitably increases the size of the device, and interference with other devices becomes a problem. Furthermore, a high-output rotary motor 362 is required as the drive source for moving the contact members 32 and 33. As a result, a new problem arises in which the design freedom of the centering mechanism 3 is greatly restricted.

[0047] Therefore, in this embodiment, before the contact members 31 to 33 shown in Figure 5 move onto the substrate S, the eccentricity direction is acquired and the orientation of the substrate S is adjusted. This centering process, including the acquisition of the eccentricity direction and the adjustment of the substrate orientation, is performed by the arithmetic processing unit 91 controlling each part of the device according to the centering program. After this centering process, the bevel etching process is performed. Thus, in this embodiment, as shown in Figure 8, the arithmetic processing unit 91 functions as an eccentricity information acquisition unit that acquires eccentricity information including the eccentricity direction, a substrate orientation adjustment unit that adjusts the orientation of the substrate S, and a movement control unit that repeats the above minute movements to position the contact members 31 to 33 until all contact with the substrate S is completed. The operation of the substrate processing device 10 equipped with the centering device according to the first embodiment will be described below with reference to Figure 8.

[0048] Figure 8 is a flowchart showing the operation of the substrate processing apparatus shown in Figure 2. In the substrate processing apparatus 10, the arithmetic processing unit 91 controls each part of the apparatus to perform a centering process (step S1) before the bevel etching process (step S2). More specifically, the following steps S11 to S17 are performed.

[0049] The arithmetic processing unit 91 moves the contact members 31-33 and the measuring unit 37 to a position radially away from the spin base 21 via the motor control unit 93. This creates sufficient transport space above the spin base 21 for the hand (not shown) of the substrate transport robot 111 to enter, and prevents the substrate S being transported by the substrate transport robot 111 from interfering with the contact members 31-33 and the measuring unit 37.

[0050] Once the completion of the transport space and prevention of interference with the substrate S are confirmed, the arithmetic processing unit 91 requests the substrate transport robot 111 to load the substrate S, and waits for the unprocessed substrate S to be transported to the substrate processing device 10 and placed on the upper surface of the spin base 21. Then, the substrate S is placed on the spin base 21 (step S11). At this point, the suction pump 24 is stopped, and the substrate S is able to move horizontally on the upper surface of the spin base 21.

[0051] Once the loading of the substrate S is complete, the substrate transport robot 111 retracts from the substrate processing device 10. Subsequently, the arithmetic processing unit 91 uses the suction pump 24 to attract and hold the substrate S on the spin base 21. The arithmetic processing unit 91 also moves the measurement unit 37 from its retracted position along the radial direction D4 to the periphery of the substrate S. After that, the arithmetic processing unit 91 rotates the spin base 21 at least once around the vertical axis AX via the motor control unit 93. As a result, the substrate S rotates together with the spin base 21 and then stops rotating. During this rotation, the arithmetic processing unit 91 receives the edge detection signal output from the measurement unit 37 as periphery information and derives the eccentricity direction D5, the amount of eccentricity, and the relative position of the notch NT (see Figure 3) where the center SC of the substrate S is eccentric from the center 21C of the spin base 21 (step S12). Here, the relative position of the notch NT means the relative position of the notch NT with respect to the eccentricity direction D5. In the first embodiment and the second and third embodiments described later, information regarding the relative position of the notch NT (corresponding to an example of the "notch position information" of the present invention) is not used. Therefore, in these embodiments, obtaining notch position information is not essential.

[0052] Next, the arithmetic processing unit 91 derives the inclination angle α of the eccentricity direction D5 with respect to the virtual line VL (step S13). Subsequently, the motor control unit 93 rotates the spin base 21 by an angle (-α) around the vertical axis AX (step S14). As a result, the eccentricity direction D5 of the substrate S becomes parallel to the virtual line VL and faces the X1 direction, and coincides with the virtual line VL. In other words, the eccentricity of the substrate S in the horizontal plane consists only of an X component, and the Y component is almost zero. After adjusting to this substrate orientation, the arithmetic processing unit 91 moves the contact members 31 to 33 by a small amount toward the substrate S from their positions at the first reference position, second reference position, and third reference position, respectively, as shown in Figure 5. By repeating this small movement, the substrate S is moved in the X2 direction by the amount of eccentricity derived in step S12. As a result, the center SC of the substrate S coincides with the center 21C of the spin base 21 (step S15).

[0053] Step S15 may be executed only once to complete the centering process, but in the first embodiment, in order to aim for higher precision positioning, the eccentricity direction of the substrate S is reacquired in the same manner as in step S12 (step S16). If the reacquired eccentricity exceeds a preset tolerance value (NO in step S17), the calculation processing unit 91 returns to step S13 and repeats steps S13 to S17.

[0054] On the other hand, if the answer in step S17 is "YES," meaning the reacquired eccentricity is less than or equal to a preset allowable value, the calculation processing unit 91 moves the contact members 31-33 and the measuring unit 37 to a position radially away from the spin base 21 using the motor control unit 93, and then proceeds to the bevel etching process (step S2).

[0055] In the bevel etching process, with the center SC of the substrate S aligned with the center 21C of the spin base 21, the arithmetic processing unit 91 rotates the substrate S around the vertical axis AX using the motor control unit 93. Then, while rotating the substrate S at, for example, 1800 revolutions per minute, the arithmetic processing unit 91 controls the processing liquid supply unit 43 to supply processing liquid to the processing liquid nozzle 41. As a result, the processing liquid is discharged from the processing liquid nozzle 41 to the periphery of the rotating substrate S. Consequently, bevel etching is performed on the entire periphery of the substrate S using the processing liquid.

[0056] Then, when the arithmetic processing unit 91 detects the elapsed processing time required for the bevel etching process of the substrate S, it issues a command to stop supplying the processing liquid to the processing liquid supply unit 43, and stops the discharge of the processing liquid. The arithmetic processing unit 91 also stops the rotation of the spin base 21. With this, the bevel etching process is completed, and the arithmetic processing unit 91 unloads the substrate S from the substrate processing device 10 in the reverse order of the substrate S loading process.

[0057] As described above, according to the first embodiment, prior to the centering operation of the substrate S (step S15), the substrate orientation is adjusted so that the eccentricity direction D5 is parallel to the imaginary line VL. Therefore, the eccentricity of the substrate S in the horizontal plane consists only of the X-direction component parallel to the imaginary line VL, and the Y-direction component perpendicular to the eccentricity direction D5 is almost zero. Consequently, the contact members 31-33 that contact the substrate S during the centering operation of the substrate S (step S15) push the substrate S along the imaginary line VL. In other words, all of the pushing force is used to move the substrate S to the opposite side of the eccentricity direction D5. Therefore, it is possible to position the substrate S with a small force. The rotary motors 352 and 362, which are the power sources of the moving mechanism 34, can be miniaturized.

[0058] Furthermore, during the centering operation, it is no longer necessary to move the substrate S in the Y direction perpendicular to the eccentricity direction D5 to correct the eccentricity. This means that movement of the substrate S in the Y direction by the contact members 32 and 33 is unnecessary, and it becomes possible to reduce the spacing between the second contact member 32 and the third contact member 33 in the Y direction. As a result, the substrate processing apparatus 10 equipped with the centering mechanism 3 can be miniaturized. Thus, according to this embodiment, there are fewer constraints regarding the arrangement of the moving mechanism 34 and the contact members, and the centering device can be designed with a high degree of freedom.

[0059] Furthermore, the elimination of the need for Y-direction correction by the contact members 32 and 33 offers the following advantages. Specifically, after the contact members 31 to 33 come into contact with the substrate S, they maintain contact and push the substrate S. Therefore, no slippage occurs between the contact members 31 to 33 and the substrate S, and wear of the contact members 31 to 33 can be suppressed. As a result, the extended lifespan of the contact members 31 to 33 reduces the frequency of replacement, thereby reducing the burden on the operator and lowering running costs.

[0060] 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. As a result, the centering process can be completed at the appropriate timing without damaging the substrate S.

[0061] Furthermore, as shown in column (a) of Figure 4, since the contact members 31 to 33 have linear regions 312, 322, and 332 that intersect with the XY plane, other effects can also be obtained. This point will be explained with reference to Figure 4.

[0062] To move the end face Se of the substrate S by pushing it from the horizontal direction, a contact member having a semi-circular tip (second embodiment) or a sharp tip, as shown in column (b) of Figure 4, or a roller-shaped contact member may be used. The same effects as in the first embodiment can be obtained when using these contact members.

[0063] However, in the second embodiment shown in column (b) of Figure 4, for example, the tip portion 393 of the contact member 39 has a semi-disc shape. In this contact member 39, the contact surface 391 facing the end face Se of the substrate S is finished in a convex shape toward the substrate S. Therefore, on the contact surface 391, the curved region 392 that intersects with a virtual horizontal plane including the substrate S placed on the upper surface of the substrate holding portion 2 has a curved shape with the center of curvature located on the contact member 39 side. As a result, when the notch NT is placed on the upper surface of the spin base 21 in a position facing the contact surface 391, a part of the tip portion 393 enters the notch NT and makes contact with the two contact points CP1 and CP2 on the curved region 392. As a result, during centering, the contact surface 391 moves to a position P1 that is advanced toward the substrate S by an eccentricity amount Lb from the position P0 where it contacts and positions the end face Se of the substrate S. As a result, the pressing position of the contact member 39 is shifted from the position for accurate centering. For example, in the centering mechanism 3 shown in Figure 3, when all of the contact members 31 to 33 were replaced with contact member 39 and the centering process was performed, the following experimental results were obtained. Here, when the substrate (semiconductor wafer with a radius of 150 mm) S placed on the spin base 21 was rotated by an appropriate rotation angle (e.g., 32°, 180°, 328°) around the vertical axis AX, and the centering process was performed with the notch NT facing the contact surface 391, the amount of displacement of the pressing position, i.e., the eccentricity, reached a maximum of 240 μm.

[0064] In contrast, in the first embodiment, the contact surfaces 311 to 331 of the contact members 31 to 33 have a planar shape. Therefore, as shown in column (a) of Figure 4, the regions on the contact surfaces 311 to 331 that intersect with a virtual horizontal plane including the substrate S placed on the upper surface of the substrate holding part 2, i.e., the contactable regions, are each linear in shape. Moreover, these linear regions 312, 321, and 332 are all longer than the arc length Ln. Therefore, as shown in the figure, when the notch NT is placed on the upper surface of the spin base 21 in a position facing the contact surface 321, the two contact points CP1 and CP2 on the linear region 322 are locked at the shoulder portion of the notch NT, effectively preventing a part of the contact member 32 from entering the notch NT. Furthermore, although the contact surface 321 moves to a position P2 that is an eccentricity La toward the substrate S side from the position P0 where it contacts and is positioned with the end face Se of the substrate S, the eccentricity La is significantly reduced compared to the eccentricity Lb in the second embodiment.

[0065] The above-described 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. However, the configuration of the contact surfaces 311, 321, and 331 in the centering mechanism 3 is not limited thereto. For example, as shown in Figure 9, the contact surfaces 311, 321, and 331 may be finished so that the contactable region intersecting the XY plane is curved (third embodiment).

[0066] Figure 9 is a schematic diagram showing the configuration of the contact member and its relationship to the notch on the substrate, as adopted in the third embodiment of the centering device according to the present invention. The main difference between this third embodiment and the first embodiment is that the contact surfaces 311, 321, and 331 have a curved shape along the end face Se of the substrate S, while the other configurations are the same as those of the first embodiment. Therefore, the following explanation will focus on the differences, and identical components will be denoted by the same reference numerals and their descriptions will be omitted.

[0067] As shown in column (a) of Figure 9, on the contact surface 321, the curved region 323 that intersects with a virtual horizontal plane including the substrate S placed on the upper surface of the substrate holding portion 2 functions as a contactable region. That is, the contact surface 321 is finished such that the center of curvature of the curved region 323 is located on the substrate S side and the radius of curvature of the curved region 323 is larger than the radius of the substrate S. Therefore, during centering, when the contact member 32 is moved toward the end face Se of the substrate S, it contacts the end face Se of the substrate S at one or two points in the curved region 323. In other words, as shown in the figure, when the notch NT is placed on the upper surface of the spin base 21 in a position facing the contact surface 321, the two contact points CP1 and CP2 on the curved region 323 are locked at the shoulder portion of the notch NT, effectively preventing a part of the contact member 32 from entering the notch NT. Furthermore, although the contact surface 321 moves to a position P3 that is an eccentricity Lc toward the substrate S side from the position P0 where it contacts and positions itself with the end face Se of the substrate S, the eccentricity Lc is reduced compared to the eccentricity La in the first embodiment. The same applies to the contact surface 311 of the contact member 31 and the contact surface 331 of the contact member 33.

[0068] Here, by changing the radius of curvature in multiple steps and determining the amount of eccentricity due to the notch NT (angle 1.119°) provided on the substrate (semiconductor wafer with radius 150 mm) S, the following results were obtained. In other words, as the radius of curvature approaches the radius of the substrate S, the amount of eccentricity L decreases. And, theoretically, when the radius of curvature matches the radius of the substrate S, it is not affected by the notch NT. However, considering the tolerance of the substrate S, it is not practical to make the radius of curvature match the radius of the substrate S. Therefore, in the third embodiment, the contact surfaces 311, 321, and 331 are finished so that the radius of curvature of the curved region 323 is larger than the radius of the substrate S.

[0069] In the first to third embodiments described above, the contact members 31 to 33 may come into contact with a notch NT, which corresponds to an example of the "notch portion" of the present invention, during the centering operation of step S15. However, by configuring the device as follows, the influence of the notch NT can be eliminated, and the centering accuracy can be further improved (fourth embodiment). The fourth embodiment of the centering device according to the present invention will be described below with reference to Figures 10 and 11.

[0070] Figure 10 schematically shows how the positional relationship between the contact member and the notch changes due to the adjustment of the substrate's orientation. For example, when the substrate S is placed on the spin base 21 (step S11), consider the case where the notch NT of the substrate S is located opposite the eccentric direction D5, as shown in column (a) of the same figure. In the first embodiment, the orientation of the substrate S is adjusted so that the eccentric direction D5 is parallel to the virtual line VL and oriented in the X1 direction (first orientation adjustment). Then, as shown in column (b) of the same figure, after this first orientation adjustment, the notch NT of the substrate S is located on the movement path PT1 of the first contact member 31. Therefore, during the centering operation, the first contact member 31 comes into contact with the notch NT.

[0071] Here, in order to obtain the same effects as in the first to third embodiments, the orientation of the substrate S may be adjusted so that the eccentricity direction D5 is parallel to the virtual line VL and oriented in the X2 direction (second orientation adjustment). Moreover, as shown in column (c) of the figure, after this second orientation adjustment, the notch NT of the substrate S is not located on any of the movement paths PT1 to PT3 of the contact members 31 to 33. Therefore, during the centering operation, none of the contact members 31 to 33 come into contact with the notch NT, and the influence of the notch NT can be eliminated.

[0072] Therefore, in the fourth embodiment, the arithmetic processing unit 91 further improves the accuracy of the centering process by controlling each part of the device, as shown in Figure 11.

[0073] Figure 11 is a flowchart showing the operation of the fourth embodiment of the centering device according to the present invention. The main difference between this fourth embodiment and the first embodiment is that the following two steps are performed before centering the substrate S (step S15). Specifically, the differences are that notch position information regarding the relative position of the notch NT with respect to the eccentric direction is acquired, and that, based on this notch position information, the substrate S is switched between the first and second orientations so that the notch NT is removed from all movement paths PT1 to PT3 of the contact members 31 to 33. The other configurations are basically the same as those of the first embodiment. Therefore, the following explanation will focus on the differences.

[0074] After the substrate S is placed on the spin base 21 (step S11), the arithmetic processing unit 91 derives information on the eccentricity direction D5, the amount of eccentricity, and the notch position of the notch NT (step S12). Of this information, the notch position information of the notch NT is important. In other words, the arithmetic processing unit 91 uses the notch position information to verify whether the notch NT is located in the movement path PT1 to PT3 when the substrate S is rotated in the opposite direction by an angle α of inclination of the eccentricity direction D5 with respect to the virtual line VL (steps S18, S19). That is, if the arithmetic processing unit 91 determines that the notch NT is not located in any of the movement paths PT1 to PT3 when the substrate S is switched to the first posture, and that no interference with the contact member occurs, the arithmetic processing unit 91 rotates the substrate S by (-α) to adjust it to the first posture (step S141), similar to step S14 of the first embodiment. Conversely, if the calculation processing unit 91 determines that the notch NT is located in one of the movement paths PT1 to PT3 when the substrate S is switched to the first position and interference with the contact member occurs, the calculation processing unit 91 rotates the substrate S by (180-α) to adjust it to the second position (step S142).

[0075] Thus, in this fourth embodiment, the calculation processing unit 91 functions as a substrate orientation adjustment unit that selectively switches between a first orientation in which the eccentric direction D5 faces the opposite side of the first contact member 31, i.e., the X1 direction side, and a second orientation in which the eccentric direction D5 faces the first contact member 31, i.e., the X2 direction side. As a result, the substrate S is adjusted to an orientation in which the notch NT is not located in any of the movement paths PT1 to PT3.

[0076] After this substrate orientation adjustment, the arithmetic processing unit 91 performs a bevel etching process (step S2) in the same manner as in the first embodiment, and unloads the substrate S from the substrate processing device 10.

[0077] As described above, according to the fourth embodiment, not only are the same effects as those of the first to third embodiments obtained, but the influence of the notch NT can also be eliminated. Therefore, the centering accuracy can be further improved.

[0078] In the first to fourth embodiments described above, high-precision centering is possible by adjusting the orientation of the substrate S before performing the centering of the substrate S shown in Figure 5. That is, the centering apparatus and method according to the first to fourth embodiments can perform an example of the "precision positioning mode" of the present invention. Here, if the orientation adjustment of the substrate S is omitted, the positioning of the substrate S can be performed at a higher speed, that is, an example of the "high-speed positioning mode" of the present invention can be performed. Therefore, the substrate processing apparatus 10 having the configuration shown in Figures 2 and 3 may be configured to perform bevel etching after selecting and executing either the precision positioning mode or the high-speed positioning mode (fifth embodiment).

[0079] Figure 12 is a flowchart showing the operation of a fifth embodiment of the centering device according to the present invention. In this fifth embodiment, the calculation processing unit 91 selects either a precision positioning mode or a high-speed positioning mode according to a command from the operator or a preset recipe (step S3). Then, in the next step S4, the calculation processing unit 91 selects and executes either the precision positioning mode (step S1A) or the high-speed positioning mode (= step S1B, in which steps S11 and SS15 are executed in this order) of the first to fourth embodiments, depending on the selected mode. After that, a bevel etching process (step S2) is performed.

[0080] By having two types of positioning modes and configuring them to be executed selectively, substrate processing (= centering process + bevel etching process) can be performed with high versatility.

[0081] 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 31-33, 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 part 35 or 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 31-33 and output a detection signal. In this case, the control unit 9 confirms that the substrate S is clamped by the contact members 31-33 based on the detection signal from the sensor.

[0082] Furthermore, in the above embodiment, 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.

[0083] 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.

[0084] 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 all centering technologies equipped in a substrate processing apparatus that processes a disc-shaped substrate while rotating it. In addition, the centering device according to the present invention may be used independently. [Industrial applicability]

[0085] 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]

[0086] 3… Centering mechanism 4. Processing liquid supply mechanism 9... Control Unit 10... Circuit board processing equipment 21…Spin base (substrate support part) 21C… (Spin Base) Center 23... Rotary drive unit 24... Suction pump (suction unit) 31...First contact member 32...Second contact member 33...Third contact member 34...Movement mechanism 37...Measurement section 91...Calculation processing unit (eccentricity information acquisition unit, substrate attitude adjustment unit, movement control unit) 211…(Spin base) top surface 231,352,362… Rotary motors D1…Movement direction (first horizontal direction) D2…Movement direction (second horizontal direction) D3…Movement direction (third horizontal direction) D5…Eccentric direction S... Circuit board SC... (Center of the circuit board) VL…Virtual Line

Claims

1. A centering device that positions a disc-shaped substrate on a substrate support so that the center of the substrate, which is placed horizontally on the upper surface of the substrate support, coincides with the center of the substrate support, A first contact member is movable in a first horizontal direction toward the center of the substrate support portion, from a first reference position located at a reference distance from the center of the substrate support portion that is longer than the radius of the substrate, within a horizontal plane. Within the aforementioned horizontal plane, a second contact member is movable in a second horizontal direction that is different from the direction toward the center of the substrate support and toward the substrate, from a second reference position located opposite the first contact member with respect to the center of the substrate support, deviating from a virtual line extending in the first horizontal direction from the center of the substrate support, and at a distance equal to the reference distance from the center of the substrate support, Within the aforementioned horizontal plane, a third contact member is movable in a third horizontal direction different from the direction toward the center of the substrate support and toward the substrate, from a third reference position located on the opposite side of the first contact member with respect to the center of the substrate support and on the opposite side of the second contact member with respect to the imaginary line, and at a distance from the center of the substrate support by the aforementioned reference distance, A moving mechanism for moving the first contact member, the second contact member, and the third contact member in the first horizontal direction, the second horizontal direction, and the third horizontal direction, respectively. A rotation drive unit that rotates the substrate support portion on which the substrate is mounted, A measuring unit for measuring the peripheral edge of the substrate placed on the substrate support portion with the first contact member, the second contact member, and the third contact member spaced apart from the end face of the substrate, The system comprises a control unit that performs the positioning by controlling the moving mechanism and the rotational drive unit, The control unit, An eccentricity information acquisition unit that determines the eccentricity direction in which the center of the substrate is eccentric from the center of the substrate support portion based on peripheral information regarding the peripheral edge of the substrate measured by the measurement unit, A substrate orientation adjustment unit that adjusts the orientation of the substrate by rotating the substrate support portion so that the eccentric direction is parallel to the virtual line, A movement control unit that, with the eccentricity direction parallel to the imaginary line, moves the first contact member, the second contact member, and the third contact member by a first, second, and third movement amount, respectively, so that the distance of each member from the center of the substrate support portion of the first contact member, the second contact member, and the third contact member is kept the same, and repeats this minute movement until all contacts of the first contact member, the second contact member, and the third contact member with the substrate are completed. A centering device characterized by having [a certain feature].

2. A centering device according to claim 1, The moving mechanism has at least one motor for moving the first contact member, the second contact member, and the third contact member. The movement control unit is a centering device that stops the repetition of the minute movement when it confirms that all of the first contact member, the second contact member, and the third contact member are in contact with the substrate based on the load torque fluctuation in the motor.

3. A centering device according to claim 1, The substrate support portion is configured to support the substrate having a notch in its peripheral edge, The eccentricity information acquisition unit acquires notch position information relating to the relative position of the notch with respect to the eccentricity direction based on the peripheral information, The substrate orientation adjustment unit is a centering device that adjusts the orientation of the substrate based on the notch position information so that the notch is out of the movement paths of the first contact member, the second contact member, and the third contact member.

4. A centering device according to claim 3, The substrate orientation adjustment unit is a centering device that selectively switches between a first orientation in which the eccentric direction faces the opposite side of the first contact member and a second orientation in which the eccentric direction faces the first contact member.

5. A centering device according to claim 4, The substrate orientation adjustment unit is, Based on the notch position information, it is determined whether the notch is located on the movement path of any of the first contact member, the second contact member, or the third contact member when the orientation of the substrate is set to one of the first orientation and the second orientation. A centering device that adjusts the orientation of the substrate to one side when the notch is not located on the movement path, and adjusts the orientation of the substrate to the other side when the notch is located on the movement path.

6. A centering device according to any one of claims 1 to 5, The control unit, Based on the peripheral information relating to the peripheral edge of the substrate measured by the measurement unit, the eccentricity direction in which the center of the substrate is eccentric from the center of the substrate support is determined, and the orientation of the substrate is adjusted by rotating the substrate support so that the eccentricity direction is parallel to the virtual line, and in a state where the eccentricity direction is parallel to the virtual line, the first contact member, the second contact member, and the third contact member are moved by a first, second, and third movement amount, respectively, so that the distance of each of them from the center of the substrate support is kept the same, and this minute movement is repeated until the contact of the first, second, and third contact members with the substrate is completed, in a precision positioning mode, After the substrate is placed on the upper surface of the substrate support portion, without adjusting the orientation of the substrate, the system is configured to perform a high-speed positioning mode in which minute movements are made by moving the first contact member, the second contact member, and the third contact member by a first, second, and third movement amount, respectively, until all contacts of the first, second, and third contact members with the substrate are completed, so that the distances of the first, second, and third contact members from the center of the substrate support portion are kept the same. A centering device that selectively switches between the high-speed positioning mode and the precision positioning mode.

7. A centering method for positioning a disc-shaped substrate on a substrate support such that the center of the substrate, which is placed horizontally on the upper surface of the substrate support, coincides with the center of the substrate support, (a) The steps of placing the substrate on the upper surface of the substrate support, with the first contact member positioned in a horizontal plane at a first reference position located at a reference distance from the center of the substrate support portion that is longer than the radius of the substrate, the second contact member positioned at a second reference position located on the opposite side of the first contact member relative to the center of the substrate support portion, deviating from a virtual line extending from the first reference position through the center of the substrate support portion and located at the reference distance from the center of the substrate support portion, and the third contact member positioned at a third reference position located on the opposite side of the first contact member relative to the center of the substrate support portion and on the opposite side of the second contact member relative to the virtual line, located at the reference distance from the center of the substrate support portion, (b) While the substrate is placed on the upper surface of the substrate support so as to be able to move horizontally, the first contact member is moved in a first horizontal direction toward the center of the substrate support from the first reference position, the second contact member and the third contact member are moved by a second amount in a second horizontal direction different from the direction toward the center of the substrate support from the second reference position and toward the substrate, and the third contact member is moved by a third amount in a third horizontal direction different from the direction toward the center of the substrate support from the third reference position and toward the substrate, and these minute movements are repeated, (c) During the repetition of the minute movement, if it is confirmed that the substrate is sandwiched between the first contact member, the second contact member and the third contact member, the minute movement is stopped. (d) Before performing steps (a) through (c), the process includes adjusting the orientation of the substrate placed on the upper surface of the substrate support, The above step (d) is, (d-1) A step of measuring the peripheral edge of the substrate placed on the upper surface of the substrate support portion, (d-2) A step of determining the eccentricity direction in which the center of the substrate is eccentric from the center of the substrate support portion based on peripheral information relating to the peripheral edge of the substrate, (d-3) A step of adjusting the orientation of the substrate by rotating the substrate support so that the eccentric direction is parallel to a virtual line extending through the center of the substrate support, A centering method characterized by including [a certain element].

8. A centering method according to claim 7, The above step (d-1) includes the step of supporting the substrate, which has a notch provided on its peripheral edge, with the substrate support portion. The above step (d-2) includes a step of acquiring notch position information relating to the relative position of the notch with respect to the eccentric direction based on the peripheral information, The step (d-3) includes adjusting the orientation of the substrate based on the notch position information so that the notch is removed from all movement paths of the first contact member, the second contact member and the third contact member. Centering method.

9. A centering method according to claim 7 or 8, A high-speed positioning mode is provided in which the positioning is performed by executing steps (a) to (c) without adjusting the orientation of the substrate after the substrate has been placed on the upper surface of the substrate support portion, By performing steps (a) to (d) described above, a precision positioning mode is provided for positioning, A centering method that can be selectively executed.

10. A substrate support portion having an upper surface that supports a substrate in a horizontal position, A centering device according to any one of claims 1 to 5, A suction unit that exhausts air between the substrate positioned by the centering device and the substrate support unit to hold the substrate in place by suction, A rotation drive unit rotates the substrate support unit, which holds the substrate by adsorption, around the center of the substrate support unit. A processing liquid supply mechanism that supplies processing liquid to the peripheral edge of the substrate, which is rotated integrally with the substrate support portion around the center of the substrate support portion, A substrate processing apparatus characterized by comprising:

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