Substrate processing device

Abstract

To suppress a fluctuation of a distance between a substrate and an electrode so that etching on the substrate is performed properly.SOLUTION: A substrate processing device 1 includes: a substrate holding part that holds a disc-shaped substrate 9; a rotation mechanism that rotates the substrate 9 together with the substrate holding part; an electrode unit 5 that has a first electrode 51 and a second electrode 52 and that is disposed in a processing position facing the substrate 9 when etching is performed; a processing liquid filling part 6 that fills a gap between the substrate 9 and the first and second electrodes 51, 52 with processing liquid; a power supply 50 that applies a voltage between the first electrode 51 and the second electrode 52; an electrode movement mechanism 73 that moves the first electrode 51 and the second electrode 52 in a direction perpendicular to main surfaces 91, 92 of the substrate 9; and a control part that acquires warpage information of the substrate 9 and that controls the electrode movement mechanism 73 on the basis of the rotation angle of the substrate 9 input from the rotation mechanism and the warpage information, when etching is performed.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a substrate processing apparatus. [Background technology]

[0002] Conventionally, in the manufacturing process of semiconductor substrates (hereinafter simply referred to as "substrates"), various processes are performed on the substrates. For example, in the substrate processing apparatuses of Patent Documents 1 and 2, a processing liquid is discharged by a processing liquid supply unit to a plurality of different positions on a substrate on which a precious metal film has been formed, and the precious metal film on the substrate is etched by contacting an anode with the processing liquid at one position and contacting a cathode with the processing liquid at another position.

[0003] Patent Document 3 discloses a substrate processing apparatus in which a substrate is rotated while being held by a plurality of support pins by generating a negative pressure in the space between the bottom surface of the substrate and the facing surface of a facing member as the substrate rotates. In this apparatus, a positioning sensor measures the vertical position of the top surface of the substrate over the entire circumference as the substrate rotates, thereby confirming whether or not a sufficient negative pressure is generated for the support pins to hold the substrate. Patent Document 4 discloses a resist film forming module in which a resist supply nozzle and an upper sensor are provided on an arm. The upper sensor moves above the center of the wafer to obtain the distance between the center of the wafer and the lower end of the upper sensor, and the height of the resist supply nozzle is adjusted by raising and lowering the resist supply nozzle based on the distance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-158300 [Patent Document 2] Patent Publication No. 2023-8390 [Patent Document 3] JP 2020-198339 A [Patent Document 4] International Publication No. 2022 / 050117 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the substrate may warp due to the stress of the deposited film. In this case, if an electrode is placed opposite the substrate to perform etching as in the substrate processing apparatuses of Patent Documents 1 and 2, the substrate may come into contact with the electrode, or the distance between the substrate and the electrode may become too large, causing the processing liquid to be cut off between the two. As a result, the substrate may not be etched properly.

[0006] The present invention has been made in consideration of the above problems, and has an object to suppress fluctuations in the distance between the substrate and the electrode and to appropriately etch the substrate. [Means for solving the problem]

[0007] A first aspect of the present invention is a substrate processing apparatus that etches a metal film on a substrate, comprising: a substrate holding section that holds a disk-shaped substrate; a rotation mechanism that rotates the substrate together with the substrate holding section; an electrode unit having a first electrode and a second electrode and that is arranged at a processing position facing the substrate when etching is performed; a processing liquid filling section that fills processing liquid between the first electrode and the second electrode and the substrate; a power source that applies a voltage between the first electrode and the second electrode; an electrode moving mechanism that moves the first electrode and the second electrode in a direction perpendicular to a main surface of the substrate; and a control section that acquires warpage information of the substrate and controls the electrode moving mechanism based on the rotation angle of the substrate input from the rotation mechanism and the warpage information when etching is performed.

[0008] A second aspect of the present invention is a substrate processing apparatus according to the first aspect, further comprising a sensor for measuring the position of the substrate in a direction perpendicular to the main surface of the substrate at a predetermined position in the circumferential direction, and the measurement value by the sensor is input to the control unit, thereby acquiring the warpage information in the control unit.

[0009] A third aspect of the present invention is the substrate processing apparatus of the second aspect, wherein the control unit performs measurement by the sensor while rotating the substrate by the rotation mechanism, acquires the warpage information, and then performs the etching.

[0010] A fourth aspect of the present invention is the substrate processing apparatus of the third aspect, wherein, in a circumferential direction, a position of the electrode unit disposed at the processing position is the same as a position of a measurement point on the substrate measured by the sensor.

[0011] A fifth aspect of the present invention is the substrate processing apparatus of the second aspect, wherein the control unit acquires the warpage information by performing measurement with the sensor in parallel with the execution of the etching.

[0012] A sixth aspect of the present invention is a substrate processing apparatus according to any one of the first to fifth aspects, wherein the electrode unit arranged at the processing position faces a peripheral portion of the substrate, and the warpage information indicates an amount of warpage of the peripheral portion.

[0013] A seventh aspect of the present invention is a substrate processing apparatus according to the sixth aspect, wherein the electrode unit arranged at the processing position faces a target portion which is part of the peripheral portion, and the processing liquid filling section ejects the processing liquid from an outlet, thereby forming a liquid filling state in which the processing liquid is filled between the target portion, the first electrode, and the second electrode.

[0014] Aspect 8 of the present invention is a substrate processing apparatus of aspect 7, wherein the first electrode is located on one main surface side of the substrate, the second electrode is located on the other main surface side of the substrate, and the first electrode and the second electrode at least partially overlap when viewed along a direction perpendicular to both main surfaces of the substrate. Effect of the Invention

[0015] According to the present invention, it is possible to suppress fluctuations in the distance between the substrate and the electrode, and to appropriately etch the substrate. [Brief description of the drawings]

[0016] [Figure 1] FIG. 2 is a diagram showing the layout of the substrate processing system. [Diagram 2] 1 is a diagram showing a configuration of a substrate processing apparatus according to a first embodiment. [Diagram 3] FIG. 2 is a diagram showing the vicinity of an electrode unit disposed at a processing position. [Figure 4] 1 is a diagram showing a flow of substrate processing in a substrate processing apparatus; [Diagram 5] FIG. 13 is a perspective view showing the electrode unit and the sensor when acquiring warpage information. [Figure 6] FIG. 4 is a perspective view showing the electrode unit and the sensor during etching. [Figure 7] 11A and 11B are diagrams for explaining movement of the electrode unit by an electrode moving mechanism. [Figure 8] FIG. 4 is a perspective view showing the electrode unit and the sensor during etching. [Figure 9] FIG. 11 is a plan view showing another example of the electrode unit. [Figure 10] FIG. 11 is a cross-sectional view showing another example of the electrode unit. [Figure 11] FIG. 11 is a cross-sectional view showing another example of the electrode unit. [Figure 12] FIG. 13 is a diagram showing a substrate processing apparatus according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] 1 is a diagram showing the layout of a substrate processing system 10. The substrate processing system 10 is a system that processes a disk-shaped semiconductor substrate 9 (hereinafter simply referred to as "substrate 9"). The substrate processing system 10 includes an indexer block 101 and a processing block 102 coupled to the indexer block 101.

[0018] The indexer block 101 includes a carrier holding unit 104, an indexer robot 105, and an IR moving mechanism 106. The carrier holding unit 104 holds a plurality of carriers 107, each capable of accommodating a plurality of substrates 9. The plurality of carriers 107 (e.g., FOUPs) are held by the carrier holding unit 104 in a state of being arranged in a predetermined carrier arrangement direction. The IR moving mechanism 106 moves the indexer robot 105 in the carrier arrangement direction. The indexer robot 105 performs an unloading operation of unloading the substrate 9 from the carrier 107, and an loading operation of loading the substrate 9 into the carrier 107. The substrate 9 is transported in a horizontal position by the indexer robot 105. A path unit 103 is provided between a center robot 109 described later in the processing block 102 and the indexer robot 105, and the indexer robot 105 transports the substrate 9 between the path unit 103 and the carrier 107. In the path section 103, the substrate 9 is temporarily held in a horizontal position.

[0019] The processing block 102 includes a plurality of (for example, four or more) processing units 108 that process the substrate 9, and a center robot 109. The processing units 108 are arranged to surround the center robot 109 in a plan view. The processing units 108 perform various processes on the substrate 9. A substrate processing apparatus described below is one of the processing units 108. The center robot 109 transfers the substrate 9 to and from the path section 103. The center robot 109 also performs a loading operation to load the substrate 9 into the processing unit 108, and an unloading operation to unload the substrate 9 from the processing unit 108. The center robot 109 also transports the substrate 9 between the processing units 108. The substrate 9 is transported by the center robot 109 in a horizontal position.

[0020] Fig. 2 is a diagram showing the configuration of the substrate processing apparatus 1 according to the first embodiment. Fig. 2 shows a part of the configuration of the substrate processing apparatus 1 in a cross section taken along a plane including a predetermined central axis J1. The substrate processing apparatus 1 is a single-wafer type apparatus that processes substrates 9 one by one, and performs electrolytic etching on a peripheral portion 93 of the substrate 9. The peripheral portion 93 of the substrate 9 includes an edge end face (apex), a bevel portion, and portions of a first main surface 91 and a second main surface 92, which will be described later, near the bevel portion.

[0021] The substrate processing apparatus 1 includes a spin chuck 2, a cleaning liquid supply unit 3, a cup unit 4, an electrode unit 5, a processing liquid filling unit 6, an electrode moving unit 7, a sensor 81, a sensor moving unit 82, a housing 11, and a control unit 19. The spin chuck 2, a part of the cleaning liquid supply unit 3, the cup unit 4, the electrode unit 5, a part of the processing liquid filling unit 6, a part of the electrode moving unit 7, the sensor 81, and a part of the sensor moving unit 82 are accommodated in the internal space of the housing 11. An airflow forming unit 12 is provided in the canopy of the housing 11, which supplies gas to the internal space and forms an airflow (so-called downflow) that flows downward. For example, an FFU (fan filter unit) is used as the airflow forming unit 12. The control unit 19 is disposed outside the housing 11 and controls each component of the substrate processing apparatus 1. The control unit 19 is realized, for example, by a computer having a CPU, a memory, etc., executing a predetermined program. A part or the whole of the control unit 19 may be realized by a programmable logic controller (PLC) or the like.

[0022] The spin chuck 2 shown in FIG. 2 includes a chuck section 21 and a rotation mechanism 22. The chuck section 21 is a substrate holding section that is substantially disk-shaped and centered on a central axis J1 extending substantially parallel to the vertical direction, and holds the substrate 9 in a horizontal position from below. The chuck section 21 is, for example, a vacuum chuck, and contacts and adsorbs the center of the lower main surface 92 of the substrate 9. Typically, the diameter of the chuck section 21 is smaller than the diameter of the substrate 9. The center of the substrate 9 on the chuck section 21 approximately overlaps with the central axis J1. In the following description, in the substrate 9 held in a horizontal position by the chuck section 21, the main surface 92 facing downward is referred to as the "second main surface 92," and the main surface 91 facing upward is referred to as the "first main surface 91." In addition, the radial direction and the circumferential direction centered on the central axis J1 are simply referred to as the "radial direction" and the "circumferential direction." The radial direction is also the radial direction of the substrate 9, and the circumferential direction is also the circumferential direction of the substrate 9.

[0023] A metal film 96, which is a processing target in the substrate processing apparatus 1, is provided on the peripheral portion 93 of the substrate 9. The thickness of the metal film 96 is, for example, several tens of nm. The metal film 96 is provided on the entirety or part of the peripheral portion 93. The metal film 96 may be present at least on the peripheral portion 93, and may be present on the first main surface 91 or the second main surface 92 in an area inside the peripheral portion 93 in addition to the peripheral portion 93. The metal film 96 may extend over substantially the entirety of the first main surface 91 or the second main surface 92 of the substrate 9. In FIG. 2, the metal film 96 is indicated by a thick line. The metal film 96 includes, for example, ruthenium (Ru). The metal film 96 may be a film including a ruthenium compound other than a film of simple ruthenium. The metal film 96 may also be a film including a metal other than ruthenium. In the present embodiment, the metal film 96 includes ruthenium.

[0024] The rotation mechanism 22 is disposed below the chuck portion 21. The rotation mechanism 22 rotates the substrate 9 together with the chuck portion 21 around the central axis J1. The rotation mechanism 22 includes a shaft 221 and a motor 222. The shaft 221 is a substantially columnar or cylindrical member centered on the central axis J1. The shaft 221 extends in the vertical direction and is connected to the center of the lower surface of the chuck portion 21. The motor 222 is an electric rotary motor that rotates the shaft 221. The rotation mechanism 22 may be a motor having another structure (e.g., a hollow motor, etc.). The rotation mechanism 22 is provided with a rotary encoder, and a signal indicating the rotation angle of the chuck portion 21 and the substrate 9 (e.g., the rotation angle of the notch of the substrate 9 based on a predetermined position in the circumferential direction) is output to the control portion 19 at a predetermined cycle.

[0025] The cleaning liquid supply unit 3 includes a cleaning liquid nozzle 31 and a cleaning liquid supply source 32. The cleaning liquid nozzle 31 is supported by a nozzle moving mechanism (not shown). The nozzle moving mechanism has, for example, a motor and a ball screw, and moves the cleaning liquid nozzle 31 approximately horizontally between a supply position above the substrate 9 and a retracted position radially outward from the substrate 9. The cleaning liquid nozzle 31 is connected to the cleaning liquid supply source 32 via a cleaning liquid line provided with a valve 321. The cleaning liquid supply source 32 supplies the cleaning liquid to the cleaning liquid nozzle 31. The cleaning liquid is, for example, pure water such as DIW (deionized water). The cleaning liquid may be an organic solvent such as IPA, or another type of liquid.

[0026] The cup section 4 includes a cup 41 and a cup lifting mechanism (not shown). The cup 41 is an annular member centered on a central axis J1. The cup 41 is disposed around the entire circumference of the substrate 9 and the chuck section 21 in the circumferential direction, and covers the sides and the bottom of the substrate 9 and the chuck section 21. The cup 41 is a liquid receiving container that receives liquid that splashes from the rotating substrate 9 toward the surroundings. The inner surface of the cup 41 is formed of, for example, a water-repellent material. The cup 41 remains stationary in the circumferential direction regardless of whether the substrate 9 is rotating or stationary. A liquid drainage port (not shown) is provided at the bottom of the cup 41 to drain the liquid received in the cup 41 to the outside of the housing 11.

[0027] The cup lifting mechanism moves the cup 41 in the vertical direction relative to the chuck unit 21. The cup lifting mechanism has, for example, a motor or an air cylinder as a drive source. The cup 41 can be moved in the vertical direction between a processing position around the substrate 9 shown in FIG. 2 and a retracted position below the processing position by the cup lifting mechanism. The cup unit 4 may include multiple cups 41 stacked in the radial direction. When the cup unit 4 includes multiple cups 41, each of the multiple cups 41 can move independently in the vertical direction, and the multiple cups 41 are switched to be used to receive the liquid according to the type of liquid splashed from the substrate 9.

[0028] The electrode unit 5 includes a first electrode 51 and a second electrode 52. Each of the first electrode 51 and the second electrode 52 is rod-shaped or cylindrical and extends in the vertical direction. The diameter of each of the electrodes 51, 52 is, for example, 2 mm or more and 20 mm or less, and preferably 4 mm or less. The material of each of the electrodes 51, 52 is, for example, platinum (Pt) or glassy carbon. The material of the electrodes 51, 52 may be other conductive materials that can be appropriately etched as described below.

[0029] As described later, the electrode unit 5 is supported by the electrode moving part 7, and is disposed at a processing position facing a part of the peripheral portion 93 when etching the peripheral portion 93 of the substrate 9. When the electrode unit 5 is disposed at the processing position, the first electrode 51 is disposed on the first main surface 91 side of the substrate 9, and the second electrode 52 is disposed on the second main surface 92 side of the substrate 9. In this embodiment, when viewed along the up-down direction, the first electrode 51 and the second electrode 52 have substantially the same size and are disposed at the same position. That is, when viewed in a plan view, substantially the entire first electrode 51 overlaps the entire second electrode 52. As described later, since etching of the metal film 96 is performed at a portion on the peripheral portion 93 facing the electrode unit 5, the portion is hereinafter referred to as a "target portion."

[0030] FIG. 3 is a diagram showing the vicinity of the electrode unit 5 arranged at the processing position. In FIG. 3, the substrate 9 is shown in cross section (cross section on a plane including the central axis J1). When the electrode unit 5 is arranged at the processing position, the surface 511 facing downward in the first electrode 51 is approximately parallel to the first main surface 91 of the substrate 9, and the surface 511 faces the peripheral portion 93 on the first main surface 91 side of the substrate 9. In addition, the surface 521 facing upward in the second electrode 52 is approximately parallel to the second main surface 92 of the substrate 9, and the surface 521 faces the peripheral portion 93 on the second main surface 92 side of the substrate 9. In the following description, the surface 511 of the first electrode 51 and the surface 521 of the second electrode 52 are referred to as "opposing surfaces 511, 521". In the example of FIG. 3, both the opposing surfaces 511, 521 are circular. A power source 50 is electrically connected to the first electrode 51 and the second electrode 52. When etching the peripheral portion 93, as described below, the processing liquid L1 is filled between the target portion of the peripheral portion 93, the first electrode 51, and the second electrode 52 by the processing liquid filling section 6, and a predetermined voltage is applied between the first electrode 51 and the second electrode 52.

[0031] As shown in FIG. 2, the processing liquid filling unit 6 includes a processing liquid nozzle 61, a processing liquid line 62, and a processing liquid supply source 63. The processing liquid nozzle 61 is supported by the electrode moving unit 7 together with the electrode unit 5. The processing liquid nozzle 61 is connected to the processing liquid supply source 63 via the processing liquid line 62. The processing liquid supply source 63 supplies the processing liquid to the processing liquid nozzle 61. A valve 621 is provided in the processing liquid line 62. As shown in FIG. 3, the processing liquid nozzle 61 is disposed radially inward from the first electrode 51 on the first main surface 91 side of the substrate 9. The processing liquid nozzle 61 is inclined with respect to the up-down direction so that the lower end where the discharge port 611 is provided is positioned radially outward from the upper end. The discharge port 611 opens toward the gap between the first electrode 51 and the peripheral portion 93. When etching the peripheral portion 93, the processing liquid L1 is discharged from the discharge port 611 toward the gap.

[0032] Typically, the treatment liquid L1 is an electrolyte, for example, an aqueous solution containing hydrogen chloride (HCl) or ammonium chloride (NH4Cl) as a solute. The concentration of the solute is, for example, 5 wt% or more, and preferably 10 wt% or more. The upper limit of the concentration of the solute is not particularly limited, but is, for example, 25 wt%. The electrolyte may contain additives, etc. The electrolyte may be non-aqueous.

[0033] As shown in FIG. 2, the electrode moving unit 7 includes a support unit 71, an arm unit 72, and an electrode moving mechanism 73. The support unit 71 supports the processing liquid nozzle 61, the first electrode 51, and the second electrode 52. In detail, as shown in FIG. 3, the support unit 71 includes a support unit main body 710 and an auxiliary moving mechanism 711. The second electrode 52 is fixed to the support unit main body 710. The auxiliary moving mechanism 711 has a fixed body and a moving body, and the fixed body is fixed to the support unit main body 710. The moving body is movable in the vertical direction relative to the fixed body. The processing liquid nozzle 61 and the first electrode 51 are fixed to the moving body. In this way, the support unit 71 supports the processing liquid nozzle 61, the first electrode 51, and the second electrode 52 in a state in which the processing liquid nozzle 61 and the first electrode 51 are movable in the vertical direction relative to the second electrode 52. The auxiliary moving mechanism 711 includes, for example, a motor and a ball screw. The auxiliary movement mechanism 711 may be realized by a linear motor or the like.

[0034] The arm portion 72 is a member extending in the radial direction. A support portion 71 is attached to one end of the arm portion 72, and the other end is supported by an electrode moving mechanism 73. The electrode moving mechanism 73 has, for example, a motor and a ball screw, and can move the arm portion 72 in the radial direction (the longitudinal direction of the arm portion 72) and the up-down direction. In other words, the electrode moving mechanism 73 moves the electrode unit 5 and the processing liquid nozzle 61 in the radial direction and the up-down direction. When etching the peripheral portion 93, the electrode moving mechanism 73 positions the electrode unit 5 and the processing liquid nozzle 61 at a processing position facing a part of the peripheral portion 93 of the substrate 9 (i.e., the target portion). When etching is completed, the electrode unit 5 and the processing liquid nozzle 61 are positioned at a retracted position radially outward of the substrate 9. The electrode moving mechanism 73 may be realized by a linear motor or the like.

[0035] The sensor 81 shown in FIG. 2 is a non-contact type positioning sensor or distance sensor, and is disposed facing the first main surface 91 of the substrate 9 at a predetermined position in the circumferential direction. The sensor 81 emits light toward the first main surface 91 of the substrate 9, and receives the light reflected from the first main surface 91. This measures the vertical position perpendicular to the main surfaces 91, 92 (i.e., the vertical position based on the sensor 81) of the measurement point irradiated with the light. The measurement value by the sensor 81 is output to the control unit 19. The sensor 81 may be one that performs measurement using ultrasonic waves or the like. Depending on the design of the substrate processing apparatus 1, the sensor 81 may be disposed facing the second main surface 92 of the substrate 9.

[0036] The sensor moving unit 82 includes an arm unit 821 and a sensor moving mechanism 822. The arm unit 821 is a member extending in a direction perpendicular to the central axis J1. The sensor 81 is attached to one end of the arm unit 821, and the other end is supported by the sensor moving mechanism 822. The sensor moving mechanism 822 has, for example, a motor and a ball screw, and is capable of moving the arm unit 821 together with the sensor 81 in a direction along the main surfaces 91 and 92 of the substrate 9. In the example of FIG. 2, the sensor moving mechanism 822 moves the sensor 81 in two directions perpendicular to the central axis J1 and perpendicular to each other. The sensor moving mechanism 822 may be realized by a linear motor, etc.

[0037] Next, a flow of processing the substrate 9 in the substrate processing apparatus 1 will be described with reference to FIG. 4. In processing the substrate 9, each component is controlled by the control unit 19 in FIG. 2. First, the substrate 9 provided with the metal film 96 is carried into the substrate processing apparatus 1 and placed on the chuck unit 21 (step S11). The substrate 9 is held by the chuck unit 21 by vacuum suction. At this time, the electrode unit 5 and the processing liquid nozzle 61 are positioned at retracted positions that do not hinder the carrying in and out of the substrate 9. The same is true for the cleaning liquid nozzle 31. After the substrate 9 is transported, a cleaning process (pre-cleaning) may be performed on the substrate 9 in the same manner as in step S16 described later.

[0038] When the substrate 9 is held, the rotation mechanism 22 starts rotating the substrate 9 at a predetermined rotation speed. As shown in Fig. 5, the sensor 81 is disposed above the peripheral portion 93 of the substrate 9, and a measurement point P by the sensor 81 is set on the peripheral portion 93 of the substrate 9. As the substrate 9 rotates, the measurement point P on the peripheral portion 93 moves in the circumferential direction relative to the substrate 9, and the position of the peripheral portion 93 in the up-down direction is measured over the entire circumference by the sensor 81. The measurement value by the sensor 81 is input to the control unit 19. The value of the rotation angle of the substrate 9 (encoder signal) is also input to the control unit 19 from the rotation mechanism 22.

[0039] In the control unit 19, a measurement value of the sensor 81 when the substrate 9 held by the chuck unit 21 is not warped is preset as a reference value, and a difference between an actual measurement value by the sensor 81 and the reference value is treated as the amount of warping of the substrate 9 at the measurement point P. The sensor 81 is essentially a warping amount measurement unit that measures the amount of warping of the substrate 9. Each measurement value of the sensor 81 is associated with the value of the rotation angle of the substrate 9 when the measurement value is obtained. In this way, warping information indicating each value of the rotation angle of the substrate 9 and the amount of warping of the peripheral portion 93 at the measurement point P at the corresponding rotation angle value is obtained (step S12). When the warping information is obtained, the rotation of the substrate 9 is stopped and the measurement by the sensor 81 is terminated. The amount of warping of the peripheral portion 93 at each value of the rotation angle of the substrate 9 may be an average value of a plurality of measurement values ​​of the sensor 81 during a plurality of rotations of the substrate 9, or the like.

[0040] Next, the electrode moving mechanism 73 moves the arm 72, so that the electrode unit 5 and the processing liquid nozzle 61 are disposed at the processing position. As a result, as shown in FIG. 6, the electrode unit 5 and the processing liquid nozzle 61 face the target portion of the peripheral portion 93 of the substrate 9. At this time, the first electrode 51 and the second electrode 52 are positioned almost directly below the sensor 81, and the position of the electrode unit 5 disposed at the processing position and the position of the measurement point P on the substrate 9 measured by the sensor 81 are the same in the circumferential direction. In the example of FIG. 6, the positions of both electrodes in the radial direction are also approximately the same. In addition, the auxiliary moving mechanism 711 shown in FIG. 3 separates the first electrode 51 and the second electrode 52 by a set distance, and the distance between the facing surface 511 of the first electrode 51 and the facing surface 521 of the second electrode 52 and the substrate 9 (the peripheral portion 93) is several mm or less. For example, when the set distance is 1 mm and the thickness of the substrate 9 is 0.8 mm, the distance between each of the electrodes 51, 52 and the substrate 9 is 0.1 mm.

[0041] When the electrode unit 5 is placed at the processing position, the rotation mechanism 22 resumes the rotation of the substrate 9. In the control unit 19, the control of the electrode moving mechanism 73 based on the warpage information is started in parallel with the rotation of the substrate 9 (step S13). Specifically, the electrode moving mechanism 73 is controlled so that the electrode unit 5 moves up and down by the warpage amount corresponding to the rotation angle value in the warpage information at the timing when each value of the rotation angle is input from the rotation mechanism 22 to the control unit 19. For example, when the amount of warpage indicates an upward warpage, the first electrode 51 and the second electrode 52 are moved upward as shown in FIG. 7. In FIG. 7, the substrate 9 with a warpage amount of 0 and the positions of the first electrode 51 and the second electrode 52 relative to the substrate 9 are indicated by two-dot chain lines. When the amount of warpage indicates a downward warpage, the electrode unit 5 is moved downward. In reality, the rotation angle value of the substrate 9 is input from the rotation mechanism 22 to the control unit 19 at a small period, so that the electrode unit 5 is moved up and down almost continuously by the electrode moving mechanism 73. As a result, the distance between the substrate 9 and each of the facing surface 511 of the first electrode 51 and the facing surface 521 of the second electrode 52 is kept approximately constant.

[0042] Next, by opening the valve 621 of the processing liquid line 62 shown in FIG. 2, the processing liquid L1 is discharged from the discharge port 611 of the processing liquid nozzle 61 toward the gap between the first electrode 51 and the peripheral portion 93. As shown in FIG. 3, the processing liquid L1 enters the gap between the first electrode 51 and the peripheral portion 93 and fills the gap. A part of the processing liquid L1 may flow radially outward around the gap. The processing liquid L1 also flows around the second main surface 92 side of the peripheral portion 93 and fills the gap between the second electrode 52 and the peripheral portion 93 by capillary action. In this way, a liquid-filled state is formed in which the processing liquid L1 is filled between the target portion of the peripheral portion 93, the first electrode 51, and the second electrode 52. In the liquid-filled state, the processing liquid L1 flows continuously between the target portion, the first electrode 51, and the second electrode 52 without interruption. In reality, on each of the first main surface 91 and the second main surface 92 of the substrate 9, the processing liquid L1 spreads slightly radially inward from the gaps between the electrodes 51, 52 and the substrate 9. Excess processing liquid L1 flows downward and is collected by the cup 41. As long as the liquid-filled state is maintained, the supply of the processing liquid L1 from the processing liquid nozzle 61 to the peripheral portion 93 may be either continuous or intermittent.

[0043] Next, a predetermined voltage is applied between the first electrode 51 and the second electrode 52 by the power source 50. In the example of FIG. 3, a higher potential is applied to the second electrode 52 than to the first electrode 51, so that the first electrode 51 becomes a cathode and the second electrode 52 becomes an anode. By applying a voltage to the electrode unit 5, the metal film 96 is etched in the target portion of the peripheral portion 93 (step S14). In reality, the portion of the metal film 96 close to the cathode is preferentially etched. The reason why the metal film 96 is etched is not necessarily clear, but it is presumed that, for example, the following chemical reaction occurs between the first electrode 51 and the second electrode 52.

[0044] On the opposing surface 511 of the first electrode 51, 2H + +2e - →H2···(1) A chemical reaction occurs, represented by

[0045] On the first electrode 51 side of the metal film 96, Ru → Ru 3+ +3e - (2) 2Cl - →Cl2+2e - (3) 2H2O→O2+4H + +4e - (4) As a result, the metal film 96 dissolves in the processing liquid L1.

[0046] On the second electrode 52 side of the metal film 96, 2H + +2e - →H2···(5) A chemical reaction occurs, represented by

[0047] On the opposing surface 521 of the second electrode 52, 2Cl - →Cl2+2e - (6) 2H2O→O2+4H + +4e - (7) In an experiment in which a processing solution was filled between the metal film and the first and second electrodes and a voltage was applied to the processing solution via the first and second electrodes, it was confirmed that the metal film was actually etched.

[0048] As described above, the substrate 9 rotates with respect to the electrode unit 5, and the target portion in the peripheral portion 93 moves in the circumferential direction relative to the substrate 9. As a result, the metal film 96 is etched over the entire circumference of the peripheral portion 93. An imaging unit (not shown) is provided above the peripheral portion 93 of the substrate 9, and an image of the peripheral portion 93 is acquired over the entire circumference. The image of the peripheral portion 93 is input to the control unit 19, and the state of the peripheral portion 93 is confirmed. Specifically, it is confirmed whether or not the metal film 96 has been removed over the entire peripheral portion 93. The presence or absence of the metal film 96 in the peripheral portion 93 can be acquired by a known inspection algorithm. The presence or absence of the metal film 96 may be confirmed by other methods. For example, the presence or absence of the metal film 96 may be detected by measuring the current flowing between the second electrode 52 and the first electrode 51.

[0049] When the metal film 96 is removed from the entire peripheral portion 93, the application of the voltage between the electrodes 51, 52 and the discharge of the processing liquid L1 from the processing liquid nozzle 61 are stopped, and etching is completed. The rotation of the substrate 9 is stopped, and the control of the electrode moving mechanism 73 based on the warpage information is terminated (step S15). Thereafter, the electrode moving mechanism 73 moves the arm portion 72 radially outward, so that the electrode unit 5 and the processing liquid nozzle 61 move away from the peripheral portion 93 to the retreated position. The electrode unit 5 may move to the retreated position while continuing the rotation of the substrate 9. In this case, the control of the electrode moving mechanism 73 based on the warpage information is continued until the electrode unit 5 moves away from the substrate 9.

[0050] Next, the rotation of the substrate 9 is resumed, and the cleaning liquid nozzle 31 is placed at a supply position above the substrate 9. Then, the cleaning liquid is supplied from the cleaning liquid nozzle 31 toward the center of the first main surface 91 of the substrate 9. The cleaning liquid spreads over the entire first main surface 91 of the substrate 9, and a cleaning process is performed to wash away the processing liquid L1 and the like adhering to the peripheral portion 93 of the substrate 9 (step S16). The cleaning liquid is scattered radially outward from the peripheral portion 93 of the substrate 9 by centrifugal force caused by the rotation of the substrate 9, and is collected by the cup 41. The cleaning liquid nozzle 31 may eject the cleaning liquid toward the peripheral portion 93. In addition, another nozzle that ejects the cleaning liquid toward the second main surface 92 side of the peripheral portion 93 may be provided.

[0051] When the cleaning process of the substrate 9 has been performed for a predetermined time, the supply of the cleaning liquid from the cleaning liquid nozzle 31 to the substrate 9 is stopped. Then, the rotation speed of the substrate 9 is increased, and the cleaning liquid on the substrate 9 is shaken off and removed. That is, the drying process of the substrate 9 is performed (step S17). When the drying process of the substrate 9 is completed, the rotation of the substrate 9 is stopped. Thereafter, the substrate 9 is unloaded from the substrate processing apparatus 1 (step S18). With the above processes, the processing of the substrate 9 in the substrate processing apparatus 1 is completed.

[0052] In the above processing example, the position of the electrode unit 5 arranged at the processing position and the position of the measurement point P of the sensor 81 are the same in the circumferential direction, but the positions of both may be shifted in the circumferential direction (see FIG. 8 described later). In this case, in the control of the electrode moving mechanism 73 based on the warpage information, a warpage amount corresponding to a rotation angle value shifted by the difference (angle) between the positions of both in the circumferential direction is used with respect to the rotation angle value of the substrate 9 input from the rotation mechanism 22. Also, when the positions of both are shifted in the circumferential direction, the measurement by the sensor 81 may be performed with the electrode unit 5 arranged at the processing position. In this case, it is preferable that the auxiliary moving mechanism 711 makes the distance between the first electrode 51 and the second electrode 52 larger than the set distance during etching, thereby avoiding contact between the substrate 9 and the electrodes 51, 52 during measurement by the sensor 81.

[0053] As described above, the substrate processing apparatus 1 of FIG. 2 includes a substrate holding section (chuck section 21 in the above), a rotation mechanism 22, an electrode unit 5, a processing liquid filling section 6, a power source 50, an electrode movement mechanism 73, and a control section 19. The substrate holding section holds a disk-shaped substrate 9. The rotation mechanism 22 rotates the substrate 9 together with the substrate holding section. The electrode unit 5 has a first electrode 51 and a second electrode 52, and is disposed at a processing position facing the substrate 9 when etching is performed. The processing liquid filling section 6 fills the processing liquid L1 between the first electrode 51 and the second electrode 52 and the substrate 9. The power source 50 applies a voltage between the first electrode 51 and the second electrode 52. The electrode movement mechanism 73 moves the first electrode 51 and the second electrode 52 in a direction perpendicular to the main surfaces 91 and 92 of the substrate 9 (here, in the up-down direction). The control unit 19 acquires the warpage information of the substrate 9, and controls the electrode moving mechanism 73 based on the rotation angle of the substrate 9 input from the rotation mechanism 22 and the warpage information when etching is performed.

[0054] Here, a comparative substrate processing apparatus is assumed in which the control of the electrode movement mechanism 73 based on the warpage information is omitted. In the comparative substrate processing apparatus, when the substrate 9 is warped, the distance between the substrate 9 and the electrodes 51, 52 varies, and the substrate 9 cannot be etched appropriately. Specifically, the substrate 9 may come into contact with the electrodes 51, 52, or the distance between the substrate 9 and the electrodes 51, 52 may become excessively large, causing the processing liquid L1 to be interrupted between them (no continuity to be obtained). In contrast, the substrate processing apparatus 1 of FIG. 2 controls the electrode movement mechanism 73 based on the warpage information, thereby suppressing the variation in the distance between the substrate 9 and the electrodes 51, 52, and allowing the substrate 9 to be etched appropriately.

[0055] Preferably, the substrate processing apparatus 1 further includes a sensor 81 for measuring the position of the substrate 9 in a direction perpendicular to the main surfaces 91, 92 of the substrate 9 at a predetermined position in the circumferential direction. The measurement value by the sensor 81 is input to the control unit 19, whereby the warpage information is acquired in the control unit 19. In this manner, by using the sensor 81 to measure the amount of warpage of the substrate 9 while it is held by the substrate holding unit, the variation in the distance between the substrate 9 and the electrodes 51, 52 can be more reliably suppressed.

[0056] Preferably, the control unit 19 performs etching after acquiring warpage information by performing measurement with the sensor 81 while rotating the substrate 9 with the rotation mechanism 22. By acquiring the warpage information in advance in this manner, even when the rotation speed of the substrate 9 is relatively high during etching, the electrode moving mechanism 73 can be accurately controlled in accordance with the warpage of the substrate 9, and fluctuations in the distance between the substrate 9 and the electrodes 51, 52 can be more reliably suppressed.

[0057] Preferably, the position of the electrode unit 5 arranged at the processing position and the position of the measurement point P on the substrate 9 by the sensor 81 are the same in the circumferential direction. In this way, when there is no positional deviation in the circumferential direction between the electrode unit 5 arranged at the processing position and the measurement point P of the sensor 81, the electrode movement mechanism 73 can be easily controlled based on the warpage information. In addition, when the positions of both in the radial direction are also approximately the same, the amount of warpage of the substrate 9 at the arrangement position of the electrode unit 5 can be measured, and the variation in the distance between the substrate 9 and the electrodes 51, 52 can be more reliably suppressed. In the substrate processing apparatus 1, when viewed along a direction perpendicular to the main surfaces 91, 92 of the substrate 9, the electrode movement mechanism 73 can change the position of the electrode unit 5, and when the sensor 81 is used for measurement, the electrode unit 5 is arranged at a position away from the measurement point P of the sensor 81 as described above. The electrode unit 5 arranged at the processing position and the measurement point P of the sensor 81 may be arranged at different positions in the radial direction.

[0058] Next, another processing example in the substrate processing apparatus 1 will be described. In this processing example, the metal film 96 on the substrate 9 is etched while acquiring warpage information of the substrate 9. Specifically, when the substrate 9 is carried into the substrate processing apparatus 1 and placed on the chuck unit 21 (FIG. 4: step S11), the electrode moving mechanism 73 places the electrode unit 5 and the processing liquid nozzle 61 at the processing position. As a result, as shown in FIG. 8, the electrode unit 5 and the processing liquid nozzle 61 face the target portion of the peripheral portion 93 of the substrate 9. After the rotation mechanism 22 starts to rotate the substrate 9, the processing liquid L1 is discharged from the processing liquid nozzle 61, and a liquid-filled state in which the processing liquid L1 is filled between the target portion, the first electrode 51, and the second electrode 52 is formed. The electrode unit 5 and the processing liquid nozzle 61 may be placed at the processing position after the substrate 9 starts to rotate.

[0059] Further, the sensor 81 is disposed above the peripheral portion 93 at a predetermined position in the circumferential direction by the sensor moving unit 82 so that the position of the measurement point P of the sensor 81 is shifted from the position of the electrode unit 5 disposed at the processing position in the circumferential direction. In the example of FIG. 8, the measurement point P of the sensor 81 is set at a position close to the upstream side of the electrode unit 5 in the rotation direction of the substrate 9. The sensor 81 measures the position of the peripheral portion 93 in the up-down direction in parallel with the rotation of the substrate 9. Each measurement value of the sensor 81 is associated with the value of the rotation angle of the substrate 9 when the measurement value is obtained. In this way, warpage information indicating each value of the rotation angle of the substrate 9 and the warpage amount of the peripheral portion 93 at the measurement point P at the corresponding rotation angle value is obtained (step S12).

[0060] In parallel with acquiring the warpage information, the control unit 19 controls the electrode moving mechanism 73 based on the warpage information (step S13). As described above, since the position of the electrode unit 5 arranged at the processing position and the position of the measurement point P of the sensor 81 are shifted in the circumferential direction, the control of the electrode moving mechanism 73 based on the warpage information uses the amount of warpage corresponding to the rotation angle value of the substrate 9 input from the rotation mechanism 22 shifted by the difference (angle) between the positions of the two in the circumferential direction.

[0061] In parallel with the acquisition of the warpage information and the control of the electrode moving mechanism 73 based on the warpage information, a predetermined voltage is applied between the first electrode 51 and the second electrode 52 by the power source 50. This causes etching of the metal film 96 in the target portion of the peripheral portion 93 (step S14). In the substrate processing apparatus 1, each portion of the peripheral portion 93 of the substrate 9 passes under the sensor 81 multiple times until etching of the metal film 96 is completed. In the warpage information, the amount of warpage for each value of the rotation angle of the substrate 9 may be updated, for example, every time measurement is performed by the sensor 81, or the initially acquired amount of warpage may be used until etching of the metal film 96 is completed.

[0062] When the metal film 96 is removed from the entire peripheral portion 93, the application of voltage between the electrodes 51, 52 and the discharge of the processing liquid L1 from the processing liquid nozzle 61 are stopped, and the etching is completed. The rotation of the substrate 9 is also stopped, and the measurement by the sensor 81 and the control of the electrode moving mechanism 73 based on the warpage information are terminated (step S15). The subsequent processing is the same as the processing example described above.

[0063] As described above, in this processing example as well, by controlling the electrode moving mechanism 73 based on the warpage information, it is possible to suppress fluctuations in the distance between the substrate 9 and the electrodes 51, 52, and to appropriately etch the substrate 9. Furthermore, the control unit 19 acquires the warpage information by performing measurements using the sensor 81 in parallel with the execution of etching. This makes it possible to shorten the time required to acquire the warpage information and perform etching.

[0064] In the example of FIG. 8, since the substrate 9 rotates at a low speed, the measurement point P of the sensor 81 is set at a position close to the upstream side of the substrate 9 in the rotation direction relative to the electrode unit 5. However, depending on the rotation speed of the substrate 9, the measurement point P of the sensor 81 may be disposed at a position away from the electrode unit 5 in the rotation direction. In FIG. 8, the sensor 81 is shown by a two-dot chain line when the measurement point P is set at a position 180° away from the electrode unit 5 in the rotation direction. In the substrate processing apparatus 1, the measurement point P of the sensor 81 may be set at a position close to the downstream side of the electrode unit 5 in the rotation direction. In this case, after the measurement value is obtained by the sensor 81, the electrode moving mechanism 73 is controlled using the measurement value after the substrate 9 rotates slightly less than one revolution. In the substrate processing apparatus 1, after the measurement value is obtained by the sensor 81 for each part of the peripheral portion 93, the position of the measurement point P of the sensor 81 with respect to the electrode unit 5 is determined so that the electrode moving mechanism 73 can be controlled based on the measurement value for that part (so that the electrode unit 5 moves up and down in time).

[0065] Incidentally, in the etching of the metal film 96 in the peripheral portion 93, as described above, the portion of the metal film 96 closest to the cathode is preferentially removed. In other words, it takes a certain amount of time to remove the portion of the metal film 96 closest to the anode. Therefore, depending on the position where the metal film 96 is attached, it may take a long time to remove the entire metal film 96 present in the peripheral portion 93.

[0066] Next, a description will be given of a preferred method for efficiently removing the entire metal film 96 present in the peripheral portion 93. In etching the metal film 96 in the peripheral portion 93, when a portion of the metal film 96 adjacent to the first electrode 51, which is the cathode, is removed, the first electrode 51 is moved slightly toward the substrate 9 by the auxiliary movement mechanism 711 shown in Fig. 3. This reduces the distance between the opposing surface 511 of the first electrode 51 and the metal film 96 remaining in the peripheral portion 93, making it possible to shorten the time required to remove the entire metal film 96 present in the peripheral portion 93.

[0067] At this time, the auxiliary movement mechanism 711 moves the processing liquid nozzle 61 together with the first electrode 51, so that the processing liquid L1 can be supplied to an appropriate position between the first electrode 51 and the substrate 9 even in a state in which the first electrode 51 is brought close to the remaining metal film 96. Depending on the design of the substrate processing apparatus 1, the auxiliary movement mechanism 711 may move only the first electrode 51. The timing at which the auxiliary movement mechanism 711 brings the first electrode 51 closer to the substrate 9 is determined based on, for example, an image of the peripheral portion 93 acquired by the imaging unit. The timing may be determined based on a current flowing between the second electrode 52 and the first electrode 51, or may be a predetermined time.

[0068] Also, instead of or together with the movement of the first electrode 51 by the auxiliary movement mechanism 711, the power source 50 may increase the voltage applied between the first electrode 51 and the second electrode 52. This can promote removal of the portion of the metal film 96 away from the first electrode 51. Furthermore, after the portion of the metal film 96 adjacent to the first electrode 51, which is the cathode, is removed, the power source 50 may invert the cathode and the anode (reverse the polarity of the first electrode 51 and the second electrode 52). This makes the first electrode 51 an anode and the second electrode 52 a cathode. As a result, etching of the portion of the metal film 96 adjacent to the second electrode 52, which is the cathode, is promoted, and it is possible to shorten the time required to remove the entire metal film 96 present in the peripheral portion 93 (i.e., the etching time). The above-mentioned method of shortening the etching time may be adopted in other examples.

[0069] FIG. 9 is a plan view showing another example of the electrode unit 5. In the electrode unit 5 of FIG. 9, the second electrode 52 located on the second main surface 92 side of the substrate 9 is a rectangular plate. The surface of the second electrode 52 facing upward is a facing surface 521 facing the substrate 9, and is approximately parallel to the second main surface 92 of the substrate 9. The facing surface 521 of the second electrode 52 is larger than the facing surface 511 of the first electrode 51 (see FIG. 3). The area of ​​the facing surface 521 is, for example, two times or more, and preferably three times or more, the area of ​​the facing surface 511. There is no particular limit to the upper limit of the area of ​​the facing surface 521, but if the facing surface 521 is excessively large, the weight of the second electrode 52 increases, so the area of ​​the facing surface 521 is, for example, 10 times or less than the area of ​​the facing surface 511. When viewed in a plan view, the entire first electrode 51 overlaps the entire second electrode 52.

[0070] As described above, the opposing surface 521 of the second electrode 52 located on the second main surface 92 side of the substrate 9 is larger than the opposing surface 511 of the first electrode 51 located on the first main surface 91 side of the substrate 9, so that the retention of the processing liquid L1 on the second electrode 52 can be improved. As a result, it is possible to easily maintain a liquid-filled state in which the processing liquid L1 is filled between the target portion of the peripheral portion 93, the first electrode 51, and the second electrode 52. In addition, since the opposing surface 521 of the second electrode 52, which is an anode, is large, the reduction reaction on the opposing surface 521 is promoted compared to the electrode unit 5 of FIG. 3. As a result, the oxidation reaction on the opposing surface 511 of the first electrode 51 is also promoted, and the etching rate of the metal film 96 is improved. In the example of FIG. 9 as well, the electrode movement mechanism 73 can be controlled based on the warpage information to suppress the variation in the distance between the substrate 9 and the electrodes 51, 52, so that the substrate 9 can be appropriately etched.

[0071] FIG. 10 is a diagram showing another example of the electrode unit, and shows a cross section of the electrode unit 5a and the processing liquid nozzle 61. In the example of FIG. 10, the processing liquid nozzle 61 is a straight nozzle facing in the vertical direction, and when placed at the processing position, the processing liquid nozzle 61 is placed above the peripheral portion 93 of the substrate 9. The processing liquid nozzle 61 is formed of an insulating material such as resin. The first electrode 51 of the electrode unit 5a is a film of a conductive material provided on the inner circumferential surface of the processing liquid nozzle 61. In other words, the processing liquid nozzle 61 is an electrode-embedded nozzle. As in the example of FIG. 9, the second electrode 52 is plate-shaped. A power source 50 is connected to the first electrode 51 and the second electrode 52.

[0072] In etching the metal film 96 on the peripheral portion 93 of the substrate 9, the processing liquid L1 is continuously discharged from the discharge port 611 of the processing liquid nozzle 61. The processing liquid L1 covers the metal film 96 on the target portion of the peripheral portion 93 and collides with the second electrode 52. In other words, a liquid column of the processing liquid L1 formed downward from the discharge port 611 contacts both the target portion of the peripheral portion 93 and the second electrode 52. In reality, the processing liquid L1 also flows around the second main surface 92 side of the peripheral portion 93 and fills the gap between the second electrode 52 and the peripheral portion 93. In this way, a liquid-filled state in which the processing liquid L1 is filled between the target portion, the first electrode 51, and the second electrode 52 is maintained. The power source 50 applies a voltage between the first electrode 51 and the second electrode 52, thereby etching the metal film 96. Furthermore, by controlling the electrode moving mechanism 73 based on the warpage information, fluctuations in the distance between the substrate 9 and the electrodes 51, 52 (particularly, fluctuations in the distance between the substrate 9 and the second electrode 52) can be suppressed, allowing etching of the substrate 9 to be performed appropriately.

[0073] FIG. 11 is a cross-sectional view showing another example of the electrode unit. The electrode unit 5b shown in FIG. 11 includes a rectangular plate-shaped first electrode 51 and a rectangular plate-shaped second electrode 52. When the electrode unit 5b is disposed at the processing position, the first electrode 51 is located on the first main surface 91 side of the substrate 9, and the second electrode 52 is located on the second main surface 92 side of the substrate 9. The surface facing downward in the first electrode 51 is a facing surface 511 facing the substrate 9, which is approximately parallel to the first main surface 91 of the substrate 9. The surface facing upward in the second electrode 52 is a facing surface 521 facing the substrate 9, which is approximately parallel to the second main surface 92 of the substrate 9. The facing surface 511 of the first electrode 51 and the facing surface 521 of the second electrode 52 are approximately parallel to each other. The distance between the first electrode 51 and the second electrode 52 is slightly larger than the thickness of the substrate 9.

[0074] The electrode unit 5b further includes an insulating member 53. The insulating member 53 is, for example, in the shape of a block made of resin, and is disposed between an outer end of the first electrode 51 and an outer end of the second electrode 52 in the radial direction. The first electrode 51 and the second electrode 52 are fixed to the insulating member 53. A through hole is provided in the first electrode 51 radially inward of the insulating member 53. A connection member 622 is provided in the processing liquid line 62 (see FIG. 2) of the processing liquid filling unit 6 at an end opposite to the processing liquid supply source 63, and the connection member 622 is inserted into and fixed to the through hole of the first electrode 51. The connection member 622 has a discharge port 623 for the processing liquid L1, and the processing liquid L1 is supplied from the discharge port 623 to a space 54 (hereinafter referred to as "processing space 54") surrounded by the insulating member 53, the first electrode 51, and the second electrode 52. 11, the connection member 622, the first electrode 51, the insulating member 53, and the second electrode 52 are integrally configured as one member. In the electrode moving mechanism 73, the auxiliary moving mechanism 711 (see FIG. 3) is omitted, and the electrode unit 5b is attached to the arm portion 72.

[0075] When etching the peripheral portion 93 of the substrate 9, the electrode unit 5b and the connection member 622 are disposed at the processing position, so that the peripheral portion 93 is inserted into the processing space 54 from the radially inner side. The processing liquid L1 is discharged from the outlet 623 of the connection member 622, and the processing space 54 is filled with the processing liquid L1. That is, a liquid-filled state is formed in which the processing liquid L1 is filled between the target portion of the peripheral portion 93, the first electrode 51, and the second electrode 52. Then, the power source 50 applies a voltage between the first electrode 51 and the second electrode 52, so that the metal film 96 is etched. The control unit 19 controls the electrode movement mechanism 73 based on the warpage information, so that the variation in the distance between the substrate 9 and the electrodes 51 and 52 can be suppressed, and the substrate 9 can be appropriately etched. Note that, as long as the liquid-filled state is maintained in the processing space 54, the processing liquid L1 may be discharged from the outlet 623 continuously or intermittently.

[0076] 11, the insulating member 53 is disposed between the first electrode 51 and the second electrode 52 outside the peripheral portion 93 of the substrate 9 and to which the first electrode 51 and the second electrode 52 are fixed. The processing liquid filling section 6 supplies the processing liquid L1 from the discharge port 623 to the processing space 54 surrounded by the insulating member 53, the first electrode 51, and the second electrode 52. This makes it possible to easily and reliably form a liquid-filled state and to appropriately etch the metal film 96 on the peripheral portion 93.

[0077] In the substrate processing apparatus 1, the substrate 9 does not necessarily need to be held in a horizontal position, and may be held in an upright state, for example. When the substrate 9 is held upright in the substrate processing apparatus 1 of FIG. 11, the orientation of the electrode unit 5b is changed so that the insulating member 53 is disposed below the upright substrate 9 (a state in which FIG. 11 is rotated 90° clockwise). In the electrode unit 5b of FIG. 11, the first electrode 51 may be located on one main surface side (e.g., the first main surface 91 side) of the substrate 9, and the second electrode 52 may be located radially outside the substrate 9. Furthermore, in the electrode unit 5b, the first electrode 51, the insulating member 53, and the second electrode 52 may be arranged in a circumferential direction on one main surface side (e.g., the first main surface 91 side) of the substrate 9.

[0078] On the other hand, in order to increase the etching rate of the metal film 96 of the peripheral portion 93, it is preferable that the first electrode 51 is located on one main surface side of the substrate 9 and the second electrode 52 is located on the other main surface side, as in the electrode units 5, 5a, 5b of FIG. 3, FIG. 9, FIG. 10, and FIG. 11. In this manner, by disposing the substrate 9 between the first electrode 51 and the second electrode 52, the metal film 96 can be etched efficiently. In the electrode units 5, 5a, 5b, when viewed along a direction perpendicular to the main surfaces 91, 92 of the substrate 9, the first electrode 51 overlaps with the second electrode 52 almost entirely, but the first electrode 51 and the second electrode 52 may only partially overlap. In the substrate processing apparatus 1, when viewed along a direction perpendicular to both main surfaces 91, 92 of the substrate 9, the first electrode 51 and the second electrode 52 at least partially overlap with each other, so that the metal film 96 can be etched efficiently.

[0079] In the above-mentioned substrate processing apparatus 1, the first electrode 51 and the second electrode 52 are arranged at approximately the same position in the circumferential direction, but the first electrode 51 and the second electrode 52 may be provided at a distance from each other. FIG. 12 is a diagram showing a substrate processing apparatus 1a according to a second embodiment. In the substrate processing apparatus 1a, both the first electrode 51 and the second electrode 52 are arranged on the first main surface 91 side of the substrate 9. Specifically, when the electrode unit 5c is arranged at a processing position facing the substrate 9, the first electrode 51 is located near the peripheral portion 93 on the first main surface 91 side. The second electrode 52 is located close to the substrate 9, separated from the first electrode 51 in the circumferential direction on the first main surface 91 side. In the example of FIG. 12, the second electrode 52 is also located near the peripheral portion 93.

[0080] The processing liquid filling unit 6 includes a first processing liquid nozzle 61a and a second processing liquid nozzle 61b, both of which are provided on the first main surface 91 side. The first processing liquid nozzle 61a is disposed near the first electrode 51 and ejects the processing liquid L1 toward between the first electrode 51 and the substrate 9. The first electrode 51 is electrically connected to the metal film 96 on the peripheral portion 93 via the processing liquid L1. The second processing liquid nozzle 61b is disposed near the second electrode 52 and ejects the processing liquid L1 toward between the second electrode 52 and the substrate 9. The second electrode 52 is electrically connected to the metal film 96 on the peripheral portion 93 via the processing liquid L1 at a position different from that of the first electrode 51. In this way, the processing liquid filling unit 6 fills the processing liquid L1 between each of the first electrode 51 and the second electrode 52 and the substrate 9, and two different (independent) contact points are provided between the first electrode 51 and the second electrode 52.

[0081] The electrode moving mechanism 73 of the substrate processing apparatus 1a includes a first electrode moving mechanism 73a and a second electrode moving mechanism 73b. The first electrode moving mechanism 73a is connected to the first electrode 51 and the first processing liquid nozzle 61a via an arm unit 72, and moves the first electrode 51 and the first processing liquid nozzle 61a in the vertical direction. The second electrode moving mechanism 73b is connected to the second electrode 52 and the second processing liquid nozzle 61b via the arm unit 72, and moves the second electrode 52 and the second processing liquid nozzle 61b in the vertical direction.

[0082] In the etching in the substrate processing apparatus 1a, a voltage is applied between the first electrode 51 and the second electrode 52 by the power source 50 while rotating the substrate 9. In the example of FIG. 12, the first electrode 51 is a cathode, and the second electrode 52 is an anode. This causes etching of the metal film 96 on the peripheral portion 93. Furthermore, the first electrode moving mechanism 73a and the second electrode moving mechanism 73b are controlled based on the warpage information, and the distance between the substrate 9 and each of the first electrode 51 and the second electrode 52 is kept substantially constant. As a result, the substrate 9 can be appropriately etched. Note that the sensor 81 is not shown in FIG. 12.

[0083] In the substrate processing apparatus 1a, it is also possible to perform etching in a region inside the peripheral portion 93. On the other hand, since the warpage of the substrate 9 is usually large at the peripheral portion 93, the above-mentioned method of controlling the electrode moving mechanism 73 based on the warpage information is particularly effective for etching the metal film 96 on the peripheral portion 93. In other words, in the substrate processing apparatus 1a, similarly to the above-mentioned substrate processing apparatus 1, it is preferable that the electrode unit 5c arranged at the processing position faces the peripheral portion 93 of the substrate 9, and the warpage information indicates the amount of warpage of the peripheral portion 93.

[0084] Incidentally, in the substrate processing apparatus 1a as well, the metal film 96 is etched in the vicinity of the first electrode 51, which is a cathode. However, when the etching progresses to a certain extent and the second electrode 52 (anode) faces the area from which the metal film 96 has been removed, the second electrode 52 is no longer electrically connected to the metal film 96. As a result, no current flows between the first electrode 51 and the second electrode 52, and etching does not progress. Also, when the metal film 96 is scattered in the peripheral portion 93, no current flows between the first electrode 51 and the second electrode 52, and etching does not progress.

[0085] In contrast, in the substrate processing apparatus 1 of FIG. 2, when etching is performed, the first electrode 51 and the second electrode 52 face a target portion, which is a part of the peripheral portion 93 of the substrate 9, and the processing liquid L1 is filled between the target portion, the first electrode 51, and the second electrode 52. As a result, the first electrode 51 and the second electrode 52 are electrically connected to the metal film 96 of the target portion through the same processing liquid L1, that is, substantially at one contact point. As a result, even if there is a region where the metal film 96 has been removed or an isolated metal film 96 exists, it is possible to appropriately etch the metal film 96. In addition, in the substrate processing apparatus 1 that supplies the processing liquid L1 only to one place on the peripheral portion 93, the consumption of the processing liquid L1 can be significantly reduced. Depending on the design of the substrate processing apparatus 1 of FIG. 2, in addition to the processing liquid nozzle 61, another processing liquid nozzle that supplies the processing liquid L1 between the second electrode 52 and the substrate 9 may be provided to more reliably form a liquid-filled state.

[0086] The substrate processing apparatus 1, 1a can be modified in various ways.

[0087] In the above embodiment, the warpage information of the substrate 9 is acquired by using the sensor 81 in the substrate processing apparatus 1, 1a, but the warpage information of the substrate 9 acquired by an external device may be input to the control unit 19 of the substrate processing apparatus 1, 1a. That is, the control unit 19 may acquire the warpage information by inputting the warpage information from the outside. For example, a sensor R1 (shown by a broken line in FIG. 1) similar to the sensor 81 is provided in the path unit 103 of the substrate processing system 10 in FIG. 1. The sensor R1 can move over the entire circumference above the peripheral portion 93 of the substrate 9 held in the path unit 103 by a moving mechanism (not shown). As a result, the warpage information indicating each angular position (for example, an angular position based on the notch) and the warpage amount of the peripheral portion 93 at the angular position is acquired for the substrate 9 before it is carried into the substrate processing apparatus 1, 1a. In the substrate processing apparatus 1, 1a, the electrode moving mechanism 73 is controlled based on the warpage information.

[0088] The substrate processing apparatus 1 of FIG. 2 may be provided with two electrode moving mechanisms for independently moving the first electrode 51 and the second electrode 52, similarly to the substrate processing apparatus 1a of FIG.

[0089] The substrate holding section that holds the substrate 9 and the rotation mechanism that rotates the substrate 9 may have structures other than the chuck section 21 and the rotation mechanism 22 in Fig. 2. For example, a plurality of rollers may be arranged in the circumferential direction around the substrate 9, and the plurality of rollers may contact the edge face or the like of the substrate 9 to hold the substrate 9, while some of the rollers rotate on their own axes to rotate the substrate 9 about the central axis J1.

[0090] The substrates processed in the substrate processing apparatus 1, 1a are not limited to semiconductor substrates, but may be glass substrates or other substrates.

[0091] The configurations in the above-described embodiment and each of the modified examples may be combined as appropriate as long as they are not mutually inconsistent. [Explanation of symbols]

[0092] 1, 1a Substrate processing apparatus 5, 5a~5c Electrode unit 6 Processing liquid filling section 9 Substrate 19 Control section 21 Chuck part 22 Rotation mechanism 50 power supply 51 1st electrode 52 2nd electrode 73 Electrode movement mechanism 81 Sensors 91, 92 (substrate) main surface 93 (Circumference of the board) 96 Metal Film 611,623 Discharge port L1 Processing liquid P measurement point

Claims

1. A substrate processing apparatus for etching a metal film on a substrate, comprising: a substrate holder for holding a disk-shaped substrate; a rotation mechanism that rotates the substrate together with the substrate holder; an electrode unit having a first electrode and a second electrode and disposed at a processing position facing the substrate during etching; a processing liquid filling section that fills a processing liquid between the first electrode and the second electrode and between the substrate and the processing liquid; a power source that applies a voltage between the first electrode and the second electrode; an electrode moving mechanism that moves the first electrode and the second electrode in a direction perpendicular to a major surface of the substrate; a control unit that acquires warpage information of the substrate and controls the electrode moving mechanism based on the rotation angle of the substrate input from the rotation mechanism and the warpage information when performing the etching; A substrate processing apparatus comprising:

2. The substrate processing apparatus according to claim 1 , a sensor for measuring a position of the substrate in a direction perpendicular to the main surface of the substrate at a predetermined position in a circumferential direction; The substrate processing apparatus includes a control unit that acquires the warpage information by inputting a measurement value obtained by the sensor into the control unit.

3. The substrate processing apparatus according to claim 2, The control unit performs the etching after acquiring the warpage information by performing measurement with the sensor while rotating the substrate with the rotation mechanism.

4. The substrate processing apparatus according to claim 3, A substrate processing apparatus, wherein, in a circumferential direction, a position of the electrode unit arranged at the processing position is the same as a position of a measurement point on the substrate measured by the sensor.

5. The substrate processing apparatus according to claim 2, The control unit performs measurement using the sensor to obtain the warpage information in parallel with the execution of the etching.

6. 6. The substrate processing apparatus according to claim 1, The electrode unit disposed at the processing position faces a peripheral portion of the substrate, and the warpage information indicates an amount of warpage of the peripheral portion.

7. 7. The substrate processing apparatus according to claim 6, The electrode unit arranged at the treatment position faces a target site that is a part of the peripheral portion, The substrate processing apparatus, wherein the processing liquid filling section discharges the processing liquid from a discharge port to form a liquid filled state in which the processing liquid fills a space between the target portion, the first electrode, and the second electrode.

8. The substrate processing apparatus according to claim 7, A substrate processing apparatus, wherein the first electrode is located on one main surface side of the substrate, the second electrode is located on the other main surface side of the substrate, and the first electrode and the second electrode at least partially overlap when viewed along a direction perpendicular to both main surfaces of the substrate.

Images