Substrate processing device

Abstract

To suppress a variation in an etching width when electrolytic etching is performed on a peripheral edge part of a substrate.SOLUTION: A substrate processing device 1 includes: a substrate holding part that holds a substrate 9 provided with a metal film 96 on a first-main-surface 91 side at a peripheral edge part 93; an electrode unit 5 that has a first electrode 51 and a second electrode 52, the electrode unit being such that, when etching is performed, the first electrode 51 is positioned near the peripheral edge part 93 on the first-main-surface side 91, and the second electrode 52 separates from the first electrode 51 and approaches the substrate 9; 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 L1; a power supply 50 that performs etching on a part of the metal film 96 positioned near the first electrode 51 by applying a voltage between the first electrode 51 and the second electrode 52; and a rotation mechanism that rotates the substrate 9 relative to the electrode unit 5. On the side surface of the first electrode 51, a region 516 of interest, which faces inward in the radial direction and which approaches the first main surface 91, has liquid repelling properties against the processing liquid L1.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. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-158300 [Patent Document 2] Patent Publication No. 2023-8390 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, when electrolytic etching as described in Patent Documents 1 and 2 is performed on a metal film provided on the periphery of a substrate, a processing liquid is filled between the periphery and each electrode facing the periphery. Then, a voltage is applied between the electrodes while rotating the substrate. In this case, the processing liquid filled between the electrode and the periphery may spread radially inward due to surface tension. In electrolytic etching, an etching reaction occurs in the area where the processing liquid spreads while connecting to the electrode (e.g., the cathode), and therefore the etching width of the metal film varies due to the variation in the spreading width of the processing liquid.

[0005] The present invention has been made in consideration of the above problems, and has an object to suppress variations in etching width when electrolytic etching is performed on the peripheral edge of a substrate. [Means for solving the problem]

[0006] A first aspect of the present invention is a substrate processing apparatus that etches a peripheral portion of a substrate, the apparatus comprising: a substrate holding section that holds a substrate having a disk shape having a first main surface and a second main surface, the substrate having a metal film provided on the first main surface side of the peripheral portion; an electrode unit having a first electrode and a second electrode, the first electrode being located near the peripheral portion on the first main surface side and the second electrode being spaced from the first electrode and close to the substrate when etching; a processing liquid filling section that fills a processing liquid between the first electrode and the second electrode and the substrate; a power source that etches a portion of the metal film located near the first electrode by applying a voltage between the first electrode and the second electrode; and a rotation mechanism that rotates the substrate relative to the electrode unit to move the portion of the peripheral portion where etching is to be performed in a circumferential direction, the processing liquid filling section being configured to fill a processing liquid between the first electrode and the second electrode and the substrate;

[0007] A second aspect of the present invention is a substrate processing apparatus of the first aspect, wherein the first electrode comprises an electrode body and a liquid-repellent material on a side of the electrode body, facing radially inward and covering an area adjacent to the first main surface, and the area of ​​interest is included on the surface of the liquid-repellent material.

[0008] A third aspect of the present invention is a substrate processing apparatus according to the first aspect (which may be either the first or second aspect), wherein the processing liquid filling section includes a processing liquid nozzle that ejects the processing liquid from the radially inner side toward the gap between the first electrode and the peripheral portion of the substrate.

[0009] A fourth aspect of the present invention is a substrate processing apparatus according to any one of the first to third aspects, wherein, when performing etching, the first electrode and the second electrode face a target portion which is a part of the peripheral portion of the substrate, and the processing liquid filling section ejects the processing liquid from an outlet, thereby forming a liquid filled state in which the processing liquid is filled between the target portion, the first electrode, and the second electrode.

[0010] A fifth aspect of the present invention is the substrate processing apparatus of the fourth aspect, wherein the first electrode and the second electrode at least partially overlap when viewed along a direction perpendicular to a main surface of the substrate.

[0011] A sixth aspect of the present invention is the substrate processing apparatus of the fourth aspect (which may be either the fourth or fifth aspect), further comprising an electrode moving mechanism for moving the electrode unit in a radial direction. Effect of the Invention

[0012] According to the present invention, when electrolytic etching is performed on the peripheral edge portion of a substrate, variation in etching width can be suppressed. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing a layout of a 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] 4 is an enlarged view showing a gap between a first electrode and a peripheral edge portion of a substrate. FIG. [Figure 6] 13 is an enlarged view showing a gap between a first electrode and a peripheral edge of a substrate in a substrate processing apparatus of a comparative example. FIG. [Figure 7] FIG. 11 is a plan view showing another example of the electrode unit. [Figure 8]FIG. 11 is a cross-sectional view showing another example of the electrode unit. [Figure 9] FIG. 13 is a diagram showing a substrate processing apparatus according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] 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.

[0015] The indexer block 101 includes a carrier holding unit 104, an indexer robot 105, and an IR movement 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 arranged in a predetermined carrier arrangement direction. The IR movement mechanism 106 moves the indexer robot 105 in the carrier arrangement direction. The indexer robot 105 performs an unloading operation to unload the substrate 9 from the carrier 107, and a loading operation to load the substrate 9 into the carrier 107. The substrate 9 is transported in a horizontal position by the indexer robot 105.

[0016] 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 indexer robot 105. 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.

[0017] 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 disk-shaped 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.

[0018] 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 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, and a part of the electrode moving unit 7 are accommodated in the internal space of the housing 11. An airflow forming unit 12 is provided in the canopy of the housing 11 to supply gas to the internal space and form an airflow (so-called downflow) flowing 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, and the like executing a predetermined program. A part or all of the control unit 19 may be realized by a programmable logic controller (PLC) or the like.

[0019] 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.

[0020] A metal film 96, which is a processing target in the substrate processing apparatus 1, is provided on the first main surface 91 side of 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 all or a part of the peripheral portion 93. On the first main surface 91 side, the metal film 96 may be present at least in the peripheral portion 93, and may be present in an area inside the peripheral portion 93 in addition to the peripheral portion 93. The metal film 96 may extend over substantially the entire first main surface 91 of the substrate 9. The metal film 96 may be present on the second main surface 92 side in addition to the first main surface 91 side. 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 this embodiment, the metal film 96 includes ruthenium.

[0021] 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 about 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 (for example, a hollow motor, etc.).

[0022] 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.

[0023] 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.

[0024] 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.

[0025] The electrode unit 5 includes a first electrode 51 and a second electrode 52. The first electrode 51 and the second electrode 52 are each rod-shaped or cylindrical extending in the vertical direction. The first electrode 51 and the second electrode 52 are spaced apart in the vertical direction. 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 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. Since the metal film 96 is etched at a portion on the peripheral portion 93 facing the electrode unit 5, the portion is hereinafter referred to as a "target portion."

[0026] 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). The first electrode 51 includes an electrode body 510 and a liquid-repellent member 512. The second electrode 52 includes an electrode body 520. Each of the electrode bodies 510, 520 is rod-shaped or cylindrical extending in the vertical direction. The diameter of each of the electrode bodies 510, 520 is, for example, 2 mm or more and 20 mm or less, and preferably 4 mm or less. In this embodiment, when viewed along the vertical direction, the electrode body 510 of the first electrode 51 and the electrode body 520 of the second electrode 52 have approximately the same size and are arranged at the same position. That is, when viewed in a plan view, approximately the entire electrode body 510 overlaps the entire electrode body 520. The material of each of the electrode bodies 510, 520 is, for example, platinum (Pt) or glassy carbon. The electrode bodies 510 and 520 may be made of other conductive materials that can be appropriately etched as described below.

[0027] When the electrode unit 5 is disposed at the processing position, a surface 511 facing downward in the electrode body 510 of 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, a surface 521 facing upward in the electrode body 520 of 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 electrode body 510 and the surface 521 of the electrode body 520 are referred to as "opposing surfaces 511, 521". In the example of FIG. 3, both the opposing surfaces 511, 521 are circular.

[0028] A power source 50 is electrically connected to the electrode body 510 of the first electrode 51 and the electrode body 520 of 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 electrode body 510, and the electrode body 520 by the processing liquid filling unit 6, and a predetermined voltage is applied between the electrode body 510 and the electrode body 520.

[0029] In the first electrode 51, the liquid-repellent member 512 covers the side surface of the electrode body 510 (a surface substantially perpendicular to the principal surfaces 91, 92 of the substrate 9). In the example of FIG. 3, the liquid-repellent member 512 is substantially semi-cylindrical, and covers a region of the side surface of the electrode body 510 that faces inward in the radial direction and is close to the first principal surface 91 of the substrate 9. Here, in the side surface of the electrode body 510, which is a cylindrical surface, the "region facing inward in the radial direction" is, for example, a region in a range of 90° (preferably a range of 120°, more preferably a range of 180°) centered on the direction from the center of the electrode body 510 toward the central axis J1. In addition, the "region close to the first principal surface 91" in the side surface of the electrode body 510 is, for example, a region in a range of 1 mm or less (preferably 2 mm or less, more preferably 3 mm or less) away from the opposing surface 511 on the side surface. The definitions of "a region facing radially inward" and "a region adjacent to the first main surface 91" are the same for a region of interest 516 described later.

[0030] In the vertical direction, the end surface of the liquid repellent member 512 on the substrate 9 side is disposed at approximately the same position as the opposing surface 511 of the electrode body 510, or is disposed between the opposing surface 511 and the substrate 9. The size of the liquid repellent member 512 is not particularly limited as long as it faces radially inward on the side surface of the electrode body 510 and can cover an area close to the first main surface 91. In one example, the liquid repellent member 512 covers a range of 180° on the side surface of the electrode body 510. The height of the liquid repellent member 512 in the vertical direction is, for example, 5 to 20 mm, and the thickness of the liquid repellent member 512 is, for example, 0.5 to 1.5 mm. The liquid repellent member 512 and the electrode body 510 are joined by any method such as adhesion.

[0031] The liquid-repellent member 512 is formed of a material that is liquid-repellent (lyophobic) to the treatment liquid L1. An example of the material is a fluororesin such as Teflon (registered trademark). The material may be a resin other than a fluororesin, or may be a material other than a resin. The liquid-repellent member 512 has a higher liquid-repellent property than the electrode body 510 of the first electrode 51. The liquid-repellent property can be evaluated, for example, by measuring the contact angle of the treatment liquid L1. A sample having a flat surface, which is made of the same material and has the same surface condition as the liquid-repellent member 512, is prepared, and the treatment liquid L1 is dropped on the surface to measure the contact angle. The same applies to the electrode body 510. The contact angle of the liquid-repellent member 512 is larger than the contact angle of the electrode body 510.

[0032] In the first electrode 51 including the electrode body 510 and the liquid-repellent member 512, the side surface exposed to the outside includes a portion of the side surface of the electrode body 510 and a portion of the surface of the liquid-repellent member 512 (the surface along the side surface of the electrode body 510). In the side surface of the first electrode 51, a region 516 (hereinafter referred to as the "attention region 516") facing radially inward and close to the first main surface 91 becomes the surface of the liquid-repellent member 512, that is, the attention region 516 is covered with the liquid-repellent member 512 and has liquid repellency against the treatment liquid L1. When the treatment liquid L1 is an aqueous solution, the liquid-repellent member 512 is a water-repellent member having water repellency (hydrophobicity), and the attention region 516 of the first electrode 51 has water repellency. In the second electrode 52, the periphery of the electrode body 520 may be covered with another member.

[0033] 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 L1 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 in 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.

[0034] Typically, the treatment liquid L1 is an electrolyte, for example hydrogen chloride (HCl) or ammonium chloride (NH 4 The electrolyte is an aqueous solution containing, as a solute, an electrolyte such as ammonium phosphate (Cl). 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 an additive, etc. The electrolyte may be non-aqueous.

[0035] 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.

[0036] 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 together with 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.

[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 carrying in the substrate 9, a cleaning process (pre-cleaning) may be performed on the substrate 9 in the same manner as in step S13 described later.

[0038] When the substrate 9 is held, the electrode moving mechanism 73 moves the arm portion 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. 3, the electrode unit 5 and the processing liquid nozzle 61 face the target portion of the peripheral portion 93 of the substrate 9. In detail, the first electrode 51 is located near the target portion on the first main surface 91 side, and the second electrode 52 is close to the target portion on the second main surface 92 side. The processing liquid nozzle 61 is disposed radially inside the first electrode 51. At this time, the distance between each of the opposing surface 511 of the first electrode 51 and the opposing surface 521 of the second electrode 52 and the substrate 9 (the peripheral portion 93) is adjusted by the auxiliary moving mechanism 711 to be several mm or less. When the electrode unit 5 and the like are disposed at the processing position, the rotation mechanism 22 starts rotating the substrate 9 at a predetermined rotation speed.

[0039] 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 continues uninterrupted between the target portion, the first electrode 51, and the second electrode 52. Excess processing liquid L1 flows downward and is collected by the cup 41.

[0040] In forming the liquid-filled state, the processing liquid nozzle 61 discharges the processing liquid L1 from the radially inner side toward the gap between the first electrode 51 and the peripheral portion 93, so that the processing liquid L1 also collides with the attention area 516 that faces the radially inner side and is close to the first main surface 91 on the side surface of the first electrode 51. Since the attention area 516 has liquid repellency against the processing liquid L1, the processing liquid L1 does not stay in the attention area 516 but flows down. As shown in FIG. 5, on the opposing surface 511 of the electrode body 510, the surface of the processing liquid L1 is formed from the vicinity of the boundary with the liquid repellent member 512 toward the first main surface 91 of the substrate 9. Therefore, on the first main surface 91, the processing liquid L1 hardly spreads radially inward from the gap between the first electrode 51 and the substrate 9. Note that, on the second main surface 92 of the substrate 9, the processing liquid L1 may spread slightly radially inward from the gap between the second electrode 52 and the substrate 9. 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.

[0041] 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 S12). 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.

[0042] On the opposing surface 511 of the first electrode 51, 2H + +2e - →H 2 (1) A chemical reaction occurs, represented by

[0043] On the first electrode 51 side of the metal film 96, Ru → Ru 3+ +3e - (2) 2Cl - →Cl 2 +2e - (3) 2H 2 O → O 2 +4H + +4e - (4) As a result, the metal film 96 dissolves in the processing liquid L1.

[0044] On the second electrode 52 side of the metal film 96, 2H + +2e - →H 2 (5) A chemical reaction occurs, represented by

[0045] On the opposing surface 521 of the second electrode 52, 2Cl - →Cl 2 +2e -(6) 2H 2 O → O 2 +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.

[0046] 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.

[0047] 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. 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. In addition, the cleaning liquid nozzle 31 is disposed 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 S13). The cleaning liquid is scattered radially outward from the peripheral portion 93 of the substrate 9 by the centrifugal force caused by the rotation of the substrate 9, and is collected by the cup 41. The cleaning liquid nozzle 31 may discharge the cleaning liquid toward the peripheral portion 93. Further, another nozzle for discharging the cleaning liquid on the second main surface 92 side of the peripheral portion 93 may be provided.

[0048] 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 S14). 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 S15). With the above processes, the processing of the substrate 9 in the substrate processing apparatus 1 is completed.

[0049] As described above, the substrate processing apparatus 1 of FIG. 2 includes a substrate holding section (chuck section 21 in the above), an electrode unit 5, a processing liquid filling section 6, a power source 50, and a rotating mechanism 22. The substrate holding section holds a disk-shaped substrate 9 having a first main surface 91 and a second main surface 92. At a peripheral portion 93 of the substrate 9, a metal film 96 is provided on the first main surface 91 side. The electrode unit 5 has a first electrode 51 and a second electrode 52, and when etching is performed, the first electrode 51 is located near the peripheral portion 93 on the first main surface 91 side, and the second electrode 52 is separated from the first electrode 51 and close to the substrate 9. 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 to etch a portion of the metal film 96 located near the first electrode 51. The rotating mechanism 22 rotates the substrate 9 relative to the electrode unit 5, thereby circumferentially moving the portion where etching is performed in the peripheral portion 93. Furthermore, by providing the liquid-repellent member 512 on the first electrode 51, a region of interest 516 on the side surface of the first electrode 51, which faces radially inward and is close to the first main surface 91, has liquid repellency with respect to the processing liquid L1.

[0050] Here, a comparative substrate processing apparatus is assumed in which the liquid-repellent member 512 is omitted from the first electrode 51. In the comparative substrate processing apparatus, as shown in FIG. 6, a region A1 on the side surface of the first electrode 51 facing inward in the radial direction and close to the first main surface 91 is the surface of the electrode body 510. The surface of the electrode body 510 is relatively highly wettable by the processing liquid L1, so that the processing liquid L1 is likely to pool in the region A1. When the pool occurs, the processing liquid L1 filled between the first electrode 51 and the peripheral portion 93 spreads inward in the radial direction due to surface tension. In reality, the spreading width of the processing liquid L1 becomes non-uniform depending on the degree of pooling, etc., so that the radial width of the region where the metal film 96 is etched in the peripheral portion 93, i.e., the etching width (cut width), varies. In FIG. 6, the variation width of the radial inner position of the region where the metal film 96 is etched is indicated by an arrow W1.

[0051] 5, the target region 516 of the first electrode 51 is liquid-repellent to the processing liquid L1, and thus the generation of liquid pools in the target region 516 is prevented. This prevents the processing liquid L1 from spreading radially inward from the gap between the first electrode 51 and the peripheral portion 93, and as a result, the etching width of the metal film 96 can be prevented from varying.

[0052] In the substrate processing apparatus 1, the liquid-repellent member 512 may be omitted, and the side surface of the electrode body 510 may have liquid repellency. For example, by performing a predetermined liquid repellency treatment on the side surface of the electrode body 510 with the opposing surface 511 of the electrode body 510 masked, it is possible to improve the liquid repellency of the side surface of the electrode body 510 compared to before the liquid repellency treatment. This realizes a first electrode 51 in which the attention area 516 has liquid repellency while omitting the liquid repellent member 512.

[0053] On the other hand, in order to easily realize the liquid-repellent attention area 516, it is preferable that the first electrode 51 includes an electrode body 510 and a liquid-repellent member 512, and the liquid-repellent member 512 covers an area on the side surface of the electrode body 510 that faces radially inward and is close to the first main surface 91. In this case, the attention area 516 is an area on the surface of the liquid-repellent member 512, that is, the attention area 516 is included in the surface of the liquid-repellent member 512. The liquid-repellent member 512 may cover the entire circumference of the electrode body 510, but in order to reduce the manufacturing cost of the substrate processing apparatus 1, it is preferable that the liquid-repellent member 512 is not provided on the radially outer side of the side surface of the electrode body 510.

[0054] The substrate processing apparatus 1 preferably further includes an electrode moving mechanism 73 that moves the electrode unit 5 in a radial direction. This makes it possible to easily change the etching width of the metal film 96. Depending on the design of the substrate processing apparatus 1, the positions of the electrode unit 5 and the processing liquid nozzle 61 may be fixed within the housing 11, and the electrode moving mechanism 73 may be omitted.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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 the 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 (invert the polarity of the first electrode 51 and the second electrode 52). This causes the electrode 51 facing the first main surface 91 to become the anode, and the electrode 52 facing the second main surface 92 to become the cathode. In other words, the electrode 52 becomes the first electrode in the vicinity of which etching of the metal film 96 occurs, and the electrode 51 becomes the second electrode. As a result, etching of the portion of the metal film 96 adjacent to the electrode 52 that has become the first electrode is accelerated, 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-described method for shortening the etching time may be adopted in other examples.

[0059] FIG. 7 is a plan view showing another example of the electrode unit 5. In FIG. 7, the processing liquid nozzle 61 is omitted. In the electrode unit 5 in FIG. 7, the second electrode 52 (the electrode body 520) located on the second main surface 92 side of the substrate 9 is a rectangular plate. The surface facing upward in the second electrode 52 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 the facing surface 511 of the electrode body 510 in FIG. 3). The area of ​​the facing surface 521 is, for example, two times or more, preferably three times or more, of the area of ​​the facing surface 511. There is no particular upper limit to 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 from above, the entire first electrode 51 overlaps the entire second electrode 52.

[0060] 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. 7, the attention area 516 of the first electrode 51 (the surface of the liquid-repellent member 512) has liquid repellency to the processing liquid L1, so that the etching width can be suppressed from varying.

[0061] FIG. 8 is a cross-sectional view showing another example of the electrode unit. In the electrode unit 5a shown in FIG. 8, the first electrode 51 includes a rectangular plate-shaped electrode body 510 and a liquid-repellent member 512 attached to the electrode body 510. The second electrode 52 includes a rectangular plate-shaped electrode body 520. When the electrode unit 5a is placed 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 electrode body 510 of 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 electrode body 520 of 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 electrode body 510 and the facing surface 521 of the electrode body 520 are approximately parallel to each other. The distance between the electrode body 510 and the electrode body 520 is slightly greater than the thickness of the substrate 9 .

[0062] One side surface of each of the electrode bodies 510, 520 is approximately perpendicular to the radial direction and faces the central axis J1. That is, the side surface of the electrode bodies 510, 520 faces radially inward. In the first electrode 51, the side surface of the electrode body 510 is covered with a liquid-repellent member 512. In the electrode unit 5a of FIG. 8, a region of interest 516 on the side surface of the first electrode 51, which faces radially inward and is close to the first main surface 91, is a region on the surface of the liquid-repellent member 512, and the region of interest 516 has liquid repellency to the treatment liquid L1.

[0063] The electrode unit 5a further includes an insulating member 53. The insulating member 53 is, for example, block-shaped and made of resin, and is disposed between the outer end of the electrode body 510 and the outer end of the electrode body 520 in the radial direction. The electrode body 510 and the electrode body 520 are fixed to the insulating member 53. A through hole is provided in the electrode body 510 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 and fixed in the through hole of the electrode body 510. 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 electrode body 510, and the electrode body 520. 8, 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 support part 71 of the electrode movement part 7 (see FIG. 3), the auxiliary movement mechanism 711 is omitted, and the electrode unit 5a is fixed to the support part main body 710.

[0064] When etching the peripheral portion 93 of the substrate 9, the electrode unit 5a 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 discharge port 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. In addition, since the attention area 516 of the first electrode 51 has liquid repellency against the processing liquid L1, it is possible to suppress the occurrence of liquid pooling in the attention area 516 and the variation in the etching width. Note that, as long as the liquid-filled state is maintained in the processing space 54, the discharge of the processing liquid L1 from the discharge port 623 may be either continuous or intermittent.

[0065] 8, 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.

[0066] 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. 8, the orientation of the electrode unit 5a is changed so that the insulating member 53 is disposed below the upright substrate 9 (a state in which FIG. 8 is rotated clockwise by 90°). In the electrode unit 5a of FIG. 8, the first electrode 51 may be located on the first main surface 91 side, and the second electrode 52 may be located on the radial outside of the substrate 9. Furthermore, on the first main surface 91 side of the substrate 9, the first electrode 51, the insulating member 53, and the second electrode 52 may be provided side by side in the circumferential direction. In this case, the radial outside of the peripheral portion 93 and the second main surface 92 side are covered with another insulating member to form the processing space 54.

[0067] 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 the first main surface 91 side of the substrate 9 and the second electrode 52 is located on the second main surface 92 side, as in the electrode units 5, 5a of FIG. 3, FIG. 7, and FIG. 8. 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, when viewed along a direction perpendicular to the main surfaces 91, 92 of the substrate 9, the electrode body 510 of the first electrode 51 is almost entirely overlapped with the electrode body 520 of the second electrode 52, but the electrode body 510 and the electrode body 520 may only be partially overlapped. In the substrate processing apparatus 1, when viewed along a direction perpendicular to the main surfaces 91, 92 of the substrate 9, the first electrode 51 (the electrode body 510 of the electrode 51) and the second electrode 52 are at least partially overlapped, so that the metal film 96 can be etched efficiently.

[0068] In the above-mentioned substrate processing apparatus 1, the first electrode 51 and the second electrode 52 are arranged at the same or close positions in the circumferential direction, but the first electrode 51 and the second electrode 52 may be provided at a distance from each other. FIG. 9 is a diagram showing a substrate processing apparatus 1a according to a second embodiment. In the electrode unit 5a of the substrate processing apparatus 1a, the first electrode 51 includes an electrode body 510 and a liquid-repellent member 512, similar to the electrode unit 5 in FIG. 3. The second electrode 52 includes an electrode body 520. When the electrode unit 5b 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 near 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. 9, the second electrode 52 is also located near the peripheral portion 93.

[0069] 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 discharges the processing liquid L1 toward between the first electrode 51 and the substrate 9. The electrode body 510 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 discharges the processing liquid L1 toward between the second electrode 52 and the substrate 9. The electrode body 520 is electrically connected to the metal film 96 on the peripheral portion 93 at a position different from the first electrode 51 via the processing liquid L1. 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. Other configurations of the substrate processing apparatus 1a are similar to those shown in FIG.

[0070] In 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 the substrate 9 is being rotated. In the example of FIG. 9, 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 in the vicinity of the first electrode 51. In addition, since the target region 516 of the first electrode 51 (the surface of the liquid-repellent member 512) has liquid repellency to the processing liquid L1, variations in the etching width are suppressed.

[0071] Incidentally, in the substrate processing apparatus 1a, when etching progresses to a certain extent and the second electrode 52 (anode) faces the region 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 stops. 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 stops.

[0072] In contrast, in the substrate processing apparatus 1 according to the first embodiment, 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. Then, by discharging the processing liquid L1 from the outlet 611 of the processing liquid nozzle 61 (or the outlet 623 of the connection member 622), a liquid-filled state is formed in which 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, at substantially 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. Moreover, 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 in FIG. 2, in addition to the above-mentioned processing liquid nozzle 61, another processing liquid nozzle may be provided for supplying processing liquid L1 between the second electrode 52 and the substrate 9, so that the liquid-filled state is more reliably formed.

[0073] The above-mentioned substrate processing apparatus 1, 1a can be modified in various ways.

[0074] In the first electrode 51, when the end face of the liquid-repellent member 512 on the substrate 9 side is located between the opposing surface 511 of the electrode body 510 and the substrate 9, a plurality of slits extending in the vertical direction may be provided in the liquid-repellent member 512 at a portion between the opposing surface 511 and the substrate 9. In this case, the processing liquid L1 discharged from the processing liquid nozzle 61 can enter the gap between the electrode body 510 and the substrate 9 through the plurality of slits. In addition, the portions between the slits of the liquid-repellent member 512 more reliably suppress the processing liquid L1 from spreading radially inward from the gap.

[0075] Filling the gap between the first electrode 51 and the second electrode 52 and the substrate 9 with the processing liquid L1 may be performed by various methods. For example, the processing liquid L1 may be supplied to the side surface of the electrode body 510 of the first electrode 51, and the processing liquid L1 may be caused to flow along the side surface, and the processing liquid L1 that reaches the opposing surface 511 may be allowed to enter the gap between the opposing surface 511 and the substrate 9. The processing liquid L1 also flows around to the second main surface 92 side and also enters the gap between the opposing surface 521 of the second electrode 52 and the substrate 9. In this way, even when the processing liquid L1 is caused to flow along the side surface of the electrode body 510, the attention area 516 on the side surface of the first electrode 51 that faces inward in the radial direction and is close to the first main surface 91 has liquid repellency against the processing liquid L1, thereby suppressing the variation in the etching width caused by the processing liquid L1 spreading inward in the radial direction. In this case, it is preferable that the radially outer area on the side surface of the first electrode 51 does not have liquid repellency.

[0076] In the substrate processing apparatus 1, the substrate 9 may be held by a substrate holder with the first main surface 91 on which the metal film 96 is formed facing downward. In this case, an electrode facing the first main surface 91 is used as a first electrode (cathode), and etching is performed on the metal film 96 on the peripheral portion 93. In addition, a target region on the side surface of the electrode is liquid repellent with respect to the processing liquid L1, thereby suppressing the processing liquid L1 from spreading radially inward.

[0077] 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 end 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. Depending on the design of the substrate processing apparatus 1, the electrode units 5, 5a, and 5b may rotate about the central axis J1 without rotating the substrate 9. The rotation mechanism in the substrate processing apparatus 1 may rotate the substrate 9 relatively to the electrode units 5, 5a, and 5b.

[0078] The substrates processed in the substrate processing apparatus 1, 1a are not limited to semiconductor substrates, but may be glass substrates or other substrates.

[0079] 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]

[0080] 1, 1a Substrate processing apparatus 5,5a,5b Electrode unit 6 Processing liquid filling section 9 Substrate 21 Chuck part 22 Rotation mechanism 50 power supply 51 1st electrode 52 2nd electrode 61 Processing liquid nozzle 73 Electrode movement mechanism 91 (of substrate) first main surface 92 (substrate) second main surface 93 (Circumference of the board) 96 Metal Film 510 (First electrode) electrode body 512 Liquid-repellent material 516 Areas of Interest 611,623 Discharge port L1 Processing liquid

Claims

1. A substrate processing apparatus that performs etching on a peripheral portion of a substrate, a substrate holder that holds a substrate having a disk shape with a first main surface and a second main surface, the substrate having a metal film provided on a peripheral portion of the substrate on the first main surface side; an electrode unit including a first electrode and a second electrode, the first electrode being located near the peripheral portion on the first main surface side and the second electrode being spaced apart from the first electrode and located near 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 to etch a portion of the metal film located near the first electrode; a rotation mechanism that rotates the substrate relative to the electrode unit to move a portion of the peripheral portion to be etched in a circumferential direction; Equipped with A substrate processing apparatus, wherein a target area on a side surface of the first electrode, facing radially inward and adjacent to the first main surface, is liquid-repellent with respect to the processing liquid.

2. The substrate processing apparatus according to claim 1 , The first electrode is An electrode body; a liquid-repellent member that faces radially inward on a side surface of the electrode body and covers an area adjacent to the first main surface; Equipped with The substrate processing apparatus, wherein the region of interest is included on the surface of the liquid-repellent member.

3. The substrate processing apparatus according to claim 1 , The substrate processing apparatus, wherein the processing liquid filling unit includes a processing liquid nozzle that ejects the processing liquid from a radially inner side toward a gap between the first electrode and the peripheral edge of the substrate.

4. 4. The substrate processing apparatus according to claim 1, When performing etching, the first electrode and the second electrode face a target portion that is a part of the peripheral portion of the substrate, 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.

5. The substrate processing apparatus according to claim 4, The substrate processing apparatus, wherein the first electrode and the second electrode at least partially overlap when viewed along a direction perpendicular to a main surface of the substrate.

6. The substrate processing apparatus according to claim 4, The substrate processing apparatus further comprises an electrode moving mechanism that moves the electrode unit in a radial direction.

Images