Substrate processing apparatus

Abstract

The substrate processing apparatus (1) of the present invention includes: a substrate holding section that holds a circular substrate (9); a rotation mechanism that rotates the substrate (9) together with the substrate holding section; an electrode unit (5) having a first electrode (51) and a second electrode (52) and being disposed at a processing position opposite to the substrate (9) during etching; a processing liquid filling section (6) that fills the space between the first electrode (51) and the second electrode (52) and the substrate (9) with processing liquid; a power supply (50) that applies a voltage between the first electrode (51) and the second electrode (52); an electrode moving mechanism (73) that moves the first electrode (51) and the second electrode (52) in a direction perpendicular to the main surfaces (91, 92) of the substrate (9); and a control section that acquires warpage information of the substrate (9) and controls the electrode moving mechanism (73) based on the rotation angle of the substrate (9) and the warpage information input from the rotation mechanism during etching.

Description

Technical Field

[0001] The present invention relates to a substrate processing apparatus. [Reference to Related Applications] This application for a patent of the present invention claims the benefit of priority from Japanese Patent Application JP2023-178362, filed on October 16, 2023, the entire disclosure of which is incorporated herein by reference. Prior Art

[0002] Previously, in the manufacturing process of a semiconductor substrate (hereinafter simply referred to as "substrate"), various processes were performed on the substrate. For example, in the substrate processing apparatuses disclosed in Japanese Unexamined Patent Application Publication No. 2021-158300 (Document 1) and Japanese Unexamined Patent Application Publication No. 2023-8390 (Document 2), on a substrate formed with a noble metal film, a processing liquid is ejected onto a plurality of portions at different positions by a processing liquid supply unit, and the noble metal film on the substrate is etched by bringing an anode into contact with the processing liquid at one portion and a cathode into contact with the processing liquid at another portion.

[0003] In addition, in Japanese Unexamined Patent Application Publication No. 2020-198339 (Document 3), a substrate processing apparatus has been disclosed in which, by rotating the substrate, a negative pressure is generated in the space between the lower surface of the substrate and the opposing surface of the opposing member, and the substrate is rotated while being held by a plurality of support pins. In this apparatus, by measuring the vertical position of the upper surface of the substrate over the entire circumference by a position sensor as the substrate rotates, it is confirmed whether sufficient negative pressure is generated for holding the substrate by the support pins. In International Publication No. 2022 / 050117 (Document 4), a resist film forming module has been disclosed in which a resist supply nozzle and an upper sensor are provided on an arm. The upper sensor moves to the center portion of the wafer, obtains the distance between the center of the wafer and the lower end of the upper sensor, and adjusts the height of the resist supply nozzle based on this distance.

[0004] Incidentally, in a substrate, warping may occur due to stress of the deposited film or the like. In this case, as in the substrate processing apparatuses of Documents 1 and 2, when etching is performed with the electrodes facing the substrate, it is possible that the substrate comes into contact with the electrodes, or the distance between the substrate and the electrodes becomes too large, and the processing liquid between the two is interrupted. As a result, etching of the substrate cannot be appropriately performed. Summary of the Invention

[0005] The present invention is directed to a substrate processing apparatus, and aims to suppress variations in the distance between the substrate and the electrodes and appropriately perform etching of the substrate.

[0006] The substrate processing apparatus according to aspect 1 of the present invention is for etching a metal film on a substrate, and includes: a substrate holding unit that holds a disk-shaped substrate; a rotation mechanism that rotates the substrate and the substrate holding unit together; an electrode unit having a first electrode and a second electrode, which is disposed at a processing position facing the substrate when etching is performed; a processing liquid filling unit that fills a processing liquid between the first electrode, 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 the main surface of the substrate; and a control unit that acquires warpage information of the substrate, and when performing the etching, controls the electrode moving mechanism based on the rotation angle of the substrate input from the rotation mechanism and the warpage information.

[0007] According to the present invention, variations in the distance between the substrate and the electrode can be suppressed, and etching of the substrate can be appropriately performed.

[0008] Aspect 2 of the present invention is a substrate processing apparatus as in aspect 1, which further includes: a sensor that measures the position of the substrate in a direction perpendicular to the main surface of the substrate at a specified position in the circumferential direction; and the warpage information is acquired in the control unit by inputting the measurement value of the sensor into the control unit.

[0009] Aspect 3 of the present invention is a substrate processing apparatus as in aspect 2, wherein after the control unit rotates the substrate by the rotation mechanism and performs the measurement by the sensor to acquire the warpage information, the etching is performed.

[0010] Aspect 4 of the present invention is a substrate processing apparatus as in aspect 3, wherein in the circumferential direction, the position of the electrode unit disposed at the processing position is the same as the position of the measurement point on the substrate of the sensor.

[0011] Aspect 5 of the present invention is a substrate processing apparatus as in aspect 2, wherein the control unit acquires the warpage information by performing the measurement by the sensor in parallel with the execution of the etching.

[0012] Aspect 6 of the present invention is a substrate processing apparatus as in any one of aspects 1 to 5, wherein the electrode unit disposed at the processing position faces the peripheral portion of the substrate, and the warpage information represents the warpage amount of the peripheral portion.

[0013] Aspect 7 of the present invention is a substrate processing apparatus as in Aspect 6, wherein the electrode unit disposed at the aforementioned processing position faces an object part that is a part of the aforementioned peripheral part; and the aforementioned processing liquid is ejected from the ejection port by the aforementioned processing liquid filling unit, and a liquid filling state in which the aforementioned processing liquid is filled between the aforementioned object part, the aforementioned first electrode, and the aforementioned second electrode is formed.

[0014] Aspect 8 of the present invention is a substrate processing apparatus as in Aspect 7, wherein the aforementioned first electrode is located on one main surface side of the aforementioned substrate, the aforementioned second electrode is located on the other main surface side of the aforementioned substrate, and in a case of observing in a direction perpendicular to the two main surfaces of the aforementioned substrate, the aforementioned first electrode and the aforementioned second electrode at least partially overlap.

[0015] The above objects and other objects, features, aspects, and advantages will be clearly understood from the following detailed description of the present invention with reference to the accompanying drawings. Brief Description of the Drawings

[0016] FIG. 1 is a diagram showing the layout of a substrate processing system. FIG. 2 is a diagram showing the configuration of a substrate processing apparatus according to the first embodiment. FIG. 3 is a diagram showing the vicinity of an electrode unit disposed at a processing position. FIG. 4 is a diagram showing the processing flow of a substrate of a substrate processing apparatus. FIG. 5 is a perspective view showing an electrode unit and a sensor when obtaining warpage information. FIG. 6 is a perspective view showing an electrode unit and a sensor during etching. FIG. 7 is a diagram for explaining the movement of an electrode unit by an electrode movement mechanism. FIG. 8 is a perspective view showing an electrode unit and a sensor during etching. FIG. 9 is a top view showing another example of an electrode unit. FIG. 10 is a cross-sectional view showing another example of an electrode unit. FIG. 11 is a cross-sectional view showing still another example of an electrode unit. FIG. 12 is a diagram showing a substrate processing apparatus according to the second embodiment. Embodiments

[0017] FIG. 1 is a diagram showing the layout of a substrate processing system 10. The substrate processing system 10 is a system for processing a disc-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., FOUP) are held by the carrier holding unit 104 in a state arranged in a specified carrier arrangement direction. The IR moving mechanism 106 moves the indexer robot 105 along the carrier arrangement direction. The indexer robot 105 performs an unloading operation of unloading the substrate 9 from the carrier 107 and a loading operation of loading the substrate 9 into the carrier 107. The substrate 9 is transported by the indexer robot 105 in a horizontal posture. A path unit 103 is provided between the central robot 109 (described later) of 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 unit 103, the substrate 9 is temporarily held in a horizontal posture.

[0019] The processing block 102 includes a plurality of (e.g., four or more) processing units 108 for processing the substrate 9 and a central robot 109. The plurality of processing units 108 are arranged to surround the central robot 109 in a plan view. Various processes for the substrate 9 are performed in the plurality of processing units 108. The substrate processing device described later is one of the plurality of processing units 108. The central robot 109 performs the handover of the substrate 9 with the path unit 103. Further, the central robot 109 performs a loading operation of loading the substrate 9 into the processing unit 108 and an unloading operation of unloading the substrate 9 from the processing unit 108. The central robot 109 also performs the transportation of the substrate 9 between the plurality of processing units 108. The substrate 9 is transported by the central robot 109 in a horizontal posture.

[0020] FIG. 2 is a diagram showing the configuration of the substrate processing device 1 of the first embodiment. In FIG. 2, a part of the configuration of the substrate processing device 1 is shown in a cross-section of a plane including a specified central axis J1. The substrate processing device 1 is a single-substrate device that processes the substrate 9 one by one, and electrolytic etching is performed on the peripheral portion 93 of the substrate 9. The peripheral portion 93 of the substrate 9 includes: an edge end face (apex, vertex), an oblique angle portion, and a portion near the oblique angle portion of the first main surface 91 and the second main surface 92 described later.

[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, sensors 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, and a part of the electrode moving unit 7, the sensors 81, and a part of the sensor moving unit 82 are housed in the internal space of the housing 11. On the top cover part of the housing 11, an air flow forming unit 12 is provided, and the air flow forming unit 12 supplies gas to the internal space to form a downward air flow (so-called downflow). As the air flow forming unit 12, for example, an FFU (Fan Filter Unit) is used. The control unit 19 is arranged 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 prescribed program. Part or all of the control unit 19 can be realized by a programmable logic controller (PLC: Programmable Logic Controller) or the like.

[0022] The spin chuck 2 shown in Fig. 2 includes a chuck part 21 and a rotation mechanism 22. The chuck part 21 is in a substantially disk shape centered on a central axis J1 extending substantially parallel to the vertical direction, and is a substrate holding part for holding the substrate 9 in a horizontal posture from below. The chuck part 21 is, for example, a vacuum chuck, and adsorbs by contacting the central part of the lower main surface 92 of the substrate 9. Typically, the diameter of the chuck part 21 is smaller than the diameter of the substrate 9. The center of the substrate 9 on the chuck part 21 substantially overlaps with the central axis J1. In the following description, in the substrate 9 held in a horizontal posture by the chuck part 21, the downward main surface 92 is referred to as the "second main surface 92", and the upward main surface 91 is referred to as the "first main surface 91". Also, 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] On the peripheral part 93 of the substrate 9, a metal film 96 which is the object to be processed by the substrate processing apparatus 1 is provided. The thickness of the metal film 96 is, for example, several tens of nm. The metal film 96 is provided on all or part of the peripheral part 93. The metal film 96 only needs to be at least located on the peripheral part 93, and in addition to the peripheral part 93, it can also be located in an area closer to the inside than the peripheral part 93 of the first main surface 91 or the second main surface 92. The metal film 96 can extend to substantially the whole of the first main surface 91 or the second main surface 92 of the substrate 9. In Fig. 2, the metal film 96 is represented by a thick line. The metal film 96 contains, for example, ruthenium (Ru). The metal film 96 can be a film containing a ruthenium compound in addition to a film of ruthenium alone. Also, the metal film 96 can be a film containing a metal other than ruthenium. In the present embodiment, the metal film 96 contains ruthenium.

[0024] The rotating mechanism 22 is disposed below the chuck portion 21. The rotating mechanism 22 rotates the substrate 9 together with the chuck portion 21 about the central axis J1. The rotating mechanism 22 includes a shaft 221 and a motor 222. The shaft 221 is a member having a substantially cylindrical or substantially cylindrical shape about the central axis J1. The shaft 221 extends in the vertical direction and is connected to the central portion of the lower surface of the chuck portion 21. The motor 222 is an electric rotary motor that rotates the shaft 221. The rotating mechanism 22 may be a motor having other structures (such as a hollow motor, etc.). A rotary encoder is provided in the rotating mechanism 22, and a signal indicating the rotation angle of the chuck portion 21 and the substrate 9 (for example, the rotation angle of the notch of the substrate 9 with respect to a specified position in the circumferential direction) is output to the control unit 19 at a specified period.

[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, etc., and moves the cleaning liquid nozzle 31 substantially horizontally between a supply position above the substrate 9 and a retracted position radially outside the substrate 9. The cleaning liquid nozzle 31 is connected to the cleaning liquid supply source 32 via a cleaning liquid pipeline provided with a valve 321. The cleaning liquid supply source 32 supplies 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 other types of liquids.

[0026] The cup portion 4 includes a cup 41 and a cup lifting mechanism (not shown). The cup 41 is an annular member about the central axis J1. The cup 41 is disposed around the substrate 9 and the chuck portion 21 over the entire circumference in the circumferential direction, covering the sides and the bottom of the substrate 9 and the chuck portion 21. The cup 41 is a liquid receiving container that receives the liquid scattered around by the rotating substrate 9. The inner surface of the cup 41 is formed of, for example, a water-repellent material. The cup 41 is stationary in the circumferential direction regardless of the rotation or rest of the substrate 9. At the bottom of the cup 41, a drain port (not shown) for discharging the liquid received by the cup 41 to the outside of the housing 11 is provided.

[0027] The cup lifting mechanism moves the cup 41 relative to the chuck portion 21 in the vertical direction. The cup lifting mechanism has, for example, a motor or a cylinder as a drive source. The cup 41 can move in the vertical direction between the processing position around the substrate 9 shown in FIG. 2 and the retracted position below the processing position by the cup lifting mechanism. The cup portion 4 may include a plurality of cups 41 stacked in the radial direction. When the cup portion 4 has a plurality of cups 41, the plurality of cups 41 can move independently in the vertical direction, and the plurality of cups 41 are switched to receive the liquid according to the type of the liquid scattered 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 in the shape of a rod or a cylinder extending 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, preferably 4 mm or less. The material of each of the electrodes 51, 52 is, for example, platinum (Pt) or glassy carbon. As the material of the electrodes 51, 52, other conductive materials that can appropriately perform the etching described later can be used.

[0029] As described later, the electrode unit 5 is supported by the electrode moving unit 7 and is disposed at the processing position facing a part of the peripheral edge portion 93 of the substrate 9 during the etching of the peripheral edge portion 93 of the substrate 9. In a state where 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. In the present embodiment, when observed in the vertical direction, the first electrode 51 and the second electrode 52 are of substantially the same size and are disposed at the same position. That is, in a plan view, substantially the entire first electrode 51 overlaps the entire second electrode 52. As described later, since the metal film 96 is etched at the portion on the peripheral edge portion 93 facing the electrode unit 5, hereinafter, this portion is referred to as the "target portion".

[0030] Figure 3 shows a view near the electrode unit 5 disposed at the processing position. In Figure 3, the substrate 9 is shown in a cross-section (a cross-section of a plane including the central axis J1). In a state where the electrode unit 5 is disposed at the processing position, the downward-facing surface 511 of the first electrode 51 is substantially parallel to the first main surface 91 of the substrate 9, and this surface 511 faces the peripheral portion 93 on the side of the first main surface 91 of the substrate 9. Also, the upward-facing surface 521 of the second electrode 52 is substantially parallel to the second main surface 92 of the substrate 9, and this surface 521 faces the peripheral portion 93 on the side of the second main surface 92 of the substrate 9. In the following description, the surfaces 511 and 521 of the first electrode 51 and the second electrode 52 are referred to as "opposing surfaces 511, 521". In the example of Figure 3, the opposing surfaces 511 and 521 are both circular. The first electrode 51 and the second electrode 52 are electrically connected to the power supply 50. When etching the peripheral portion 93, as will be described later, a processing liquid L1 is filled in the processing liquid filling portion 6 between the target portion of the peripheral portion 93, the first electrode 51, and the second electrode 52, and a predetermined voltage is applied between the first electrode 51 and the second electrode 52.

[0031] As shown in Figure 2, the processing liquid filling portion 6 includes a processing liquid nozzle 61, a processing liquid pipeline 62, and a processing liquid supply source 63. The processing liquid nozzle 61 is supported by the electrode moving portion 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 pipeline 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 pipeline 62. As shown in Figure 3, the processing liquid nozzle 61 is disposed on the side of the first main surface 91 of the substrate 9 inside the first electrode 51 in the radial direction. The processing liquid nozzle 61 is inclined with respect to the vertical direction such that the lower end provided with the ejection port 611 is located outside the upper end in the radial direction. The ejection 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 ejected from the ejection port 611 into the gap.

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

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

[0034] The arm portion 72 is a member extending in the radial direction. The support portion 71 is attached to one end of the arm portion 72, and the other end is supported by the 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 length direction of the arm portion 72) and the vertical 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 vertical direction. When etching the peripheral portion 93, the electrode unit 5 and the processing liquid nozzle 61 are arranged at a processing position facing a part of the peripheral portion 93 of the substrate 9 (i.e., the target portion) by the electrode moving mechanism 73. When the etching is completed, the electrode unit 5 and the processing liquid nozzle 61 are arranged at a retracted position radially outside the substrate 9. The electrode moving mechanism 73 can be realized by a linear motor or the like.

[0035] The sensor 81 shown in FIG. 2 is a non-contact position sensor or a distance sensor, and is arranged to face the first main surface 91 of the substrate 9 at a specified position in the circumferential direction. The sensor 81 emits light to the first main surface 91 of the substrate 9 and receives the reflected light of the light from the first main surface 91. Thereby, for the measurement point irradiated with the light, the position in the vertical direction perpendicular to the main surfaces 91 and 92 (i.e., the position in the vertical direction based on the sensor 81) is measured. The measured value of the sensor 81 is output to the control unit 19. The sensor 81 can be one that measures by ultrasonic waves or the like. Also, according to the design of the substrate processing apparatus 1, the sensor 81 can be arranged to face the second main surface 92 of the substrate 9.

[0036] The sensor moving unit 82 includes an arm portion 821 and a sensor moving mechanism 822. The arm portion 821 is a member extending in a direction perpendicular to the central axis J1. A sensor 81 is mounted at one end of the arm portion 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 can move the arm portion 821 and the sensor 81 together in a direction along the main surfaces 91, 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 orthogonal to each other. The sensor moving mechanism 822 can be realized by a linear motor or the like.

[0037] Next, the processing flow of the substrate 9 in the substrate processing apparatus 1 will be described with reference to FIG. 4. In the processing of the substrate 9, each component is controlled by the control unit 19 of 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 portion 21 (step S11). The substrate 9 is held on the chuck portion 21 by vacuum adsorption. At this time, the electrode unit 5 and the processing liquid nozzle 61 are arranged at retracted positions that do not obstruct the loading and unloading of the substrate 9. The same applies to the cleaning liquid nozzle 31. In addition, after the substrate 9 is transported, a cleaning process (pre-cleaning) of the substrate 9 can be performed in the same manner as in step S16 described later.

[0038] After holding the substrate 9, the rotation of the substrate 9 at a specified rotation speed is started by the rotation mechanism 22. As shown in FIG. 5, the sensor 81 is arranged above the peripheral portion 93 of the substrate 9, and the measurement point P of the sensor 81 is set on the peripheral portion 93 of the substrate 9. By the rotation of the substrate 9, the measurement point P on the peripheral portion 93 moves circumferentially relative to the substrate 9, and the sensor 81 measures the position of the peripheral portion 93 in the vertical direction over the entire circumference. The measured value of the sensor 81 is input to the control unit 19. In the control unit 19, the value of the rotation angle of the substrate 9 (encoder signal) is also input from the rotation mechanism 22.

[0039] In the control unit 19, the measured value of the sensor 81 when the substrate 9 held by the chuck unit 21 has no warpage is preset as a reference value, and the difference between the actual measured value of the sensor 81 and the reference value is treated as the warpage amount of the substrate 9 at the measurement point P. The sensor 81 is substantially a warpage measurement unit that measures the warpage amount of the substrate 9. The value of the rotation angle of the substrate 9 when the measured value is obtained is associated with each measured value of the sensor 81. Thereby, 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 of the rotation angle value is obtained (step S12). When obtaining the warpage information, the rotation of the substrate 9 is stopped, and the measurement of the sensor 81 is completed. The warpage amount of the peripheral portion 93 for each value of the rotation angle of the substrate 9 may be an average value of a plurality of measured values of the sensor 81 for a plurality of rotations of the substrate 9 or the like.

[0040] Subsequently, the arm portion 72 is moved by the electrode moving mechanism 73, and the electrode unit 5 and the processing liquid nozzle 61 are arranged at the processing position. Thereby, 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 located substantially directly below the sensor 81, and in the circumferential direction, the position of the electrode unit 5 arranged at the processing position is the same as the position of the measurement point P on the substrate 9 of the sensor 81. In the example of FIG. 6, the positions of the two in the radial direction are also substantially the same. Further, by the auxiliary moving mechanism 711 shown in FIG. 3, the first electrode 51 and the second electrode 52 are separated by a set distance, and 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 (of the peripheral portion 93) is 1 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 disposed at the processing position, the rotation mechanism 22 is restarted to rotate the substrate 9. In the control unit 19, in parallel with the rotation of the substrate 9, the control of the electrode movement mechanism 73 based on the warpage information is started (step S13). Specifically, when the rotation mechanism 22 inputs the timing of each value of the rotation angle to the control unit 19, the electrode movement mechanism 73 is controlled such that the electrode unit 5 moves in the vertical direction by the warpage amount corresponding to the value of the rotation angle in the warpage information. For example, when the warpage amount indicates an upward warpage, as shown in FIG. 7, the first electrode 51 and the second electrode 52 are moved upward. 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. Also, when the warpage amount indicates a downward warpage, the electrode unit 5 is moved downward. In practice, since the rotation mechanism 22 inputs the values of the rotation angle of the substrate 9 to the control unit 19 at a minute period, the electrode movement mechanism 73 moves the electrode unit 5 in the vertical direction substantially continuously. As a result, the distances between the opposing surfaces 511 of the first electrode 51 and the opposing surfaces 521 of the second electrode 52 and the substrate 9 are maintained substantially constant.

[0042] Subsequently, by opening the valve 621 of the processing liquid pipeline 62 shown in FIG. 2, the processing liquid L1 is ejected from the ejection port 611 of the processing liquid nozzle 61 into 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 is filled in the gap. A part of the processing liquid L1 may flow radially outward around the gap. The processing liquid L1 also wraps around to the second main surface 92 side of the peripheral portion 93 and is filled in the gap between the second electrode 52 and the peripheral portion 93 by capillary action. Thus, a liquid filling state in which the processing liquid L1 is filled between the target portion, the first electrode 51, and the second electrode 52 in the peripheral portion 93 is formed. In the liquid filling state, the processing liquid L1 is continuous without interruption between the target portion, the first electrode 51, and the second electrode 52. In practice, in each of the first main surface 91 and the second main surface 92 of the substrate 9, the processing liquid L1 also slightly expands radially inward from the gap between the electrodes 51, 52 and the substrate 9. The excess processing liquid L1 flows downward and is recovered by the cup 41. In addition, if the liquid filling 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] Subsequently, 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 potential higher than that of the first electrode 51 is given to the second electrode 52, the first electrode 51 is the cathode, and the second electrode 52 is the anode. By applying a voltage to the electrode unit 5, etching of the metal film 96 is performed on the target portion of the peripheral portion 93 (step S14). Actually, the portion of the metal film 96 close to the cathode is preferentially etched. The reason for etching the metal film 96 is not necessarily clear, but it is presumed that the following chemical reactions occur between the first electrode 51 and the second electrode 52.

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

[0045] On the first electrode 51 side of the metal film 96, the chemical reactions represented by Ru→Ru 3++3e -···(2) 2Cl -→Cl 2+2e -···(3) 2H 2O→O 2+4H ++4e -···(4) occur. Thereby, the metal film 96 is dissolved in the treatment liquid L1.

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

[0047] On the facing surface 521 of the second electrode 52, the chemical reactions represented by 2Cl -→Cl 2+2e -···(6) 2H 2O→O 2+4H ++4e -···(7) occur. In addition, in an experiment in which a treatment liquid is filled between the metal film, the first electrode, and the second electrode, and a voltage is applied to the treatment liquid via the first electrode and the second electrode, it was actually confirmed that the metal film was etched.

[0048] As described above, the substrate 9 rotates relative to the electrode unit 5, and the target portion of the peripheral portion 93 moves circumferentially relative to the substrate 9. Thereby, 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 images of the peripheral portion 93 are acquired over the entire circumference. The images of the peripheral portion 93 are input to the control unit 19 to confirm the state of the peripheral portion 93. Specifically, it is confirmed whether the metal film 96 has been removed from the entire peripheral portion 93. The presence or absence of the metal film 96 on the peripheral portion 93 can be obtained by a well-known inspection algorithm. The presence or absence of the metal film 96 can also be confirmed by other methods. For example, by measuring the current flowing between the second electrode 52 and the first electrode 51, the presence or absence of the metal film 96 can be detected.

[0049] After the metal film 96 has been removed from the entire peripheral portion 93, the application of voltage between the electrodes 51 and 52 and the ejection of the processing liquid L1 from the processing liquid nozzle 61 are stopped, and the etching is ended. Also, the rotation of the substrate 9 is stopped, and the control of the electrode moving mechanism 73 based on the warpage information ends (step S15). Thereafter, the arm portion 72 is moved radially outward by the electrode moving mechanism 73, and the electrode unit 5 and the processing liquid nozzle 61 move away from the peripheral portion 93 to the retracted position. In addition, the rotation of the substrate 9 can be continued, and the electrode unit 5 moves to the retracted position. In this case, the control of the electrode moving mechanism 73 based on the warpage information is continued until the electrode unit 5 is far from the substrate 9.

[0050] Subsequently, the rotation of the substrate 9 is restarted, and the cleaning liquid nozzle 31 is arranged at the supply position above the substrate 9. Then, the cleaning liquid is supplied from the cleaning liquid nozzle 31 to the central portion 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 for flushing away the processing liquid L1 and the like attached to the peripheral portion 93 of the substrate 9 is performed (step S16). The cleaning liquid is scattered radially outward from the peripheral portion 93 of the substrate 9 by the centrifugal force during the rotation of the substrate 9 and is recovered by the cup 41. In addition, the cleaning liquid nozzle 31 can also eject the cleaning liquid to the peripheral portion 93. Also, other nozzles for ejecting the cleaning liquid can be provided on the second main surface 92 side of the peripheral portion 93.

[0051] After 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. Subsequently, the rotation speed of the substrate 9 is increased, and the cleaning liquid on the substrate 9 is thrown off and removed. That is, a drying process of the substrate 9 is performed (step S17). When the drying process of the substrate 9 ends, the rotation of the substrate 9 is stopped. Thereafter, the substrate 9 is taken out of the substrate processing apparatus 1 (step S18). Through the above processing, the processing of the substrate 9 in the substrate processing apparatus 1 is completed.

[0052] In the above processing example, in the circumferential direction, the position of the electrode unit 5 disposed at the processing position is the same as the position of the measurement point P of the sensor 81, but the positions of the two may be offset in the circumferential direction (refer to FIG. 8 described later). In this case, in the control of the electrode moving mechanism 73 based on the warpage information, the value of the rotation angle of the substrate 9 input to the spin rotation mechanism 22 is used, and the warpage amount corresponding to the rotation angle value after offset by the difference amount (angle) of the positions of the two in the circumferential direction. Further, in the case where the positions of the two are offset in the circumferential direction, the measurement of the sensor 81 can be performed in a state where the electrode unit 5 is disposed at the processing position. In this case, in the auxiliary moving mechanism 711, it is preferable that the distance between the first electrode 51 and the second electrode 52 is larger than the set distance at the time of etching, whereby contact between the substrate 9 and the electrodes 51 and 52 is avoided during the measurement of the sensor 81.

[0053] As described above, the substrate processing apparatus 1 of FIG. 2 includes: a substrate holding unit (the chuck unit 21 in the above), a rotation mechanism 22, an electrode unit 5, a processing liquid filling unit 6, a power source 50, an electrode moving mechanism 73, and a control unit 19. The substrate holding unit holds the disk-shaped substrate 9. The rotation mechanism 22 rotates the substrate 9 together with the substrate holding unit. 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 unit 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 moving 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, the vertical 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 to the spin rotation mechanism 22 and the warpage information when etching is performed.

[0054] Here, a comparative example of a substrate processing apparatus in which the control of the electrode moving mechanism 73 based on the warpage information is omitted is considered. In the substrate processing apparatus of the comparative example, when warpage occurs in the substrate 9, the distance between the substrate 9 and each of the electrodes 51 and 52 changes, and etching of the substrate 9 cannot be appropriately performed. Specifically, sometimes the substrate 9 contacts the electrodes 51 and 52, or the distance between the substrate 9 and the electrodes 51 and 52 becomes too large, and the processing liquid L1 between the two is interrupted (no conduction is obtained). In contrast, in the substrate processing apparatus 1 of FIG. 2, by controlling the electrode moving mechanism 73 based on the warpage information, the change in the distance between the substrate 9 and the electrodes 51 and 52 can be suppressed, and etching of the substrate 9 can be appropriately performed.

[0055] Preferably, the substrate processing apparatus 1 further includes a sensor 81 that measures the position of the substrate 9 in a direction perpendicular to the main surfaces 91 and 92 of the substrate 9 at a specified position in the circumferential direction. By inputting the measurement value of the sensor 81 into the control unit 19, the above warpage information is obtained in the control unit 19. Thus, by measuring the warpage amount of the substrate 9 held by the substrate holding unit using the sensor 81, the variation in the distance between the substrate 9 and the electrodes 51 and 52 can be more reliably suppressed.

[0056] Preferably, after obtaining the warpage information by rotating the substrate 9 by the rotation mechanism 22 and measuring the sensor 81, the control unit 19 performs etching. Thus, by obtaining the warpage information in advance, even when the rotation speed of the substrate 9 is high during etching, the electrode movement mechanism 73 can be controlled with high precision in accordance with the warpage of the substrate 9, and the variation in the distance between the substrate 9 and the electrodes 51 and 52 can be more reliably suppressed.

[0057] Preferably, in the circumferential direction, the position of the electrode unit 5 disposed at the processing position is the same as the position of the measurement point P on the substrate 9 of the sensor 81. Thus, when there is no circumferential position deviation between the electrode unit 5 disposed at the processing position and the measurement point P of the sensor 81, the control of the electrode movement mechanism 73 based on the warpage information can be easily performed. Further, when the positions of both in the radial direction are also substantially the same, the warpage amount 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 and 52 can be more reliably suppressed. In addition, in the substrate processing apparatus 1, when observed in a direction perpendicular to the main surfaces 91 and 92 of the substrate 9, the electrode movement mechanism 73 can change the position of the electrode unit 5. At the time of measurement by the sensor 81, as described above, the electrode unit 5 is disposed at a position away from the measurement point P of the sensor 81. The electrode unit 5 disposed at the processing position and the measurement point P of the sensor 81 can be disposed at different positions in the radial direction.

[0058] Next, another processing example of the substrate processing apparatus 1 will be described. In this other processing example, the warpage information of the substrate 9 is acquired, and the metal film 96 on the substrate 9 is etched. Specifically, when the substrate 9 is carried into the substrate processing apparatus 1 and placed on the chuck portion 21 (FIG. 4: step S11), the electrode unit 5 and the processing liquid nozzle 61 are arranged at the processing position by the electrode moving mechanism 73. Thereby, 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 rotating the substrate 9, the processing liquid L1 is ejected from the processing liquid nozzle 61, and a liquid filling 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 can be arranged at the processing position after the rotation of the substrate 9 starts.

[0059] Further, the sensor 81 is arranged above the peripheral portion 93 at a specified position in the circumferential direction by the sensor moving unit 82 such that the position of the measurement point P of the sensor 81 in the circumferential direction is offset from the position of the electrode unit 5 arranged at the processing position. In the example of FIG. 8, the measurement point P of the sensor 81 is set at a position closer to the upstream side in the rotation direction of the substrate 9 with respect to the electrode unit 5. In the sensor 81, the position of the peripheral portion 93 in the vertical direction is measured in parallel with the rotation of the substrate 9. The value of the rotation angle of the substrate 9 when the measurement value is obtained is associated with each measurement value of the sensor 81. Thereby, the 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 of the rotation angle value is acquired (step S12).

[0060] In the control unit 19, in parallel with the acquisition of the warpage information, the control of the electrode moving mechanism 73 based on the warpage information is performed (step S13). As described above, in the circumferential direction, 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 offset. Therefore, in the control of the electrode moving mechanism 73 based on the warpage information, the value of the rotation angle of the substrate 9 input to the rotation mechanism 22 and the warpage amount corresponding to the rotation angle value offset by the difference amount (angle) of the two positions in the circumferential direction are used.

[0061] Also, 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 supply 50. Thereby, etching of the metal film 96 is performed on 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 a plurality of times until the etching of the metal film 96 is completed. In the warpage information, the warpage amount for each value of the rotation angle of the substrate 9 can be updated, for example, each time the measurement by the sensor 81 is performed, and the first acquired warpage amount can be used until the etching of the metal film 96 is completed.

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

[0063] As described above, in this processing example, by controlling the electrode moving mechanism 73 based on the warpage information, it is also possible to suppress the change in the distance between the substrate 9 and the electrodes 51 and 52, and appropriately perform the etching of the substrate 9. Further, the control unit 19 acquires the warpage information by performing the measurement by the sensor 81 in parallel with the execution of the etching. Thereby, the time required for the acquisition of the warpage information and the etching can be shortened.

[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 approaching the upstream side in the rotation direction of the substrate 9 with respect to the electrode unit 5. However, the measurement point P of the sensor 81 can be arranged at a position separated from the electrode unit 5 in the rotation direction according to the rotation speed of the substrate 9 or the like. In FIG. 8, the sensor 81 in the case where the measurement point P is set at a position separated by 180° from the electrode unit 5 in the rotation direction is indicated by a two-dot chain line. In the substrate processing apparatus 1, the measurement point P of the sensor 81 can be set at a position approaching the downstream side in the rotation direction with respect to the electrode unit 5. In this case, after obtaining the measurement value of the sensor 81, the control of the electrode moving mechanism 73 using the measurement value is performed after the substrate 9 rotates slightly less than one turn. In the substrate processing apparatus 1, the position of the measurement point P of the sensor 81 with respect to the electrode unit 5 is determined in such a manner that the control of the electrode moving mechanism 73 based on the measurement value for the portion can be performed after obtaining the measurement value of the sensor 81 for each portion of the peripheral portion 93 (in such a manner that the vertical movement of the electrode unit 5 is timely).

[0065] Now, in the etching of the metal film 96 at the peripheral portion 93, as described above, the portion of the metal film 96 close to the cathode is preferentially removed. In other words, for the portion of the metal film 96 close to the anode, it takes a certain amount of time to remove. Therefore, sometimes depending on the position where the metal film 96 adheres, it takes a long time to remove the entire metal film 96 located at the peripheral portion 93.

[0066] Next, a preferred method for efficiently removing the entire metal film 96 located at the peripheral portion 93 will be described. In the etching of the metal film 96 at the peripheral portion 93, when removing the portion of the metal film 96 close to the cathode, i.e., the first electrode 51, the first electrode 51 is slightly moved toward the substrate 9 side by the auxiliary movement mechanism 711 shown in FIG. 3. Thereby, the distance between the facing surface 511 of the first electrode 51 and the metal film 96 remaining at the peripheral portion 93 is reduced, and the time required to remove the entire metal film 96 located at the peripheral portion 93 can be shortened.

[0067] At this time, the processing liquid nozzle 61 is moved together with the first electrode 51 by the auxiliary movement mechanism 711, and in a state where the first electrode 51 is close to the remaining metal film 96, the processing liquid L1 can also be supplied to an appropriate position between the first electrode 51 and the substrate 9. According to the design of the substrate processing apparatus 1, the auxiliary movement mechanism 711 can move only the first electrode 51. The timing for moving the first electrode 51 close to the substrate 9 by the auxiliary movement mechanism 711 is determined, for example, based on an image of the peripheral portion 93 obtained by the imaging unit. This timing can be determined based on the current flowing between the second electrode 52 and the first electrode 51, or can be a preset time.

[0068] Also, instead of the movement of the first electrode 51 performed by the auxiliary movement mechanism 711, or in addition to the movement of the first electrode 51, the voltage applied by the power supply 50 between the first electrode 51 and the second electrode 52 can be increased. Thereby, the removal of the portion of the metal film 96 far from the first electrode 51 can be promoted. Further, after removing the portion of the metal film 96 close to the cathode, i.e., the first electrode 51, the power supply 50 can reverse the cathode and the anode (reverse the polarities of the first electrode 51 and the second electrode 52). Thereby, the first electrode 51 becomes the anode and the second electrode 52 becomes the cathode. As a result, the etching of the portion of the metal film 96 close to the second electrode 52 which is the cathode can be promoted, and the time required to remove the entire metal film 96 located at the peripheral portion 93 (i.e., the etching time) can be shortened. The above method for shortening the etching time can be adopted in other examples.

[0069] FIG. 9 is a top view showing another example of the electrode unit 5. In the electrode unit 5 of FIG. 9, the second electrode 52 on the second main surface 92 side of the substrate 9 is a rectangular plate shape. In the second electrode 52, the surface facing upward is the facing surface 521 facing the substrate 9, and is substantially 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 (refer to FIG. 3). The area of the facing surface 521 is, for example, more than twice the area of the facing surface 511, preferably more than three times. The upper limit of the area of the facing surface 521 is not particularly limited, but if the facing surface 521 becomes too large, the weight of the second electrode 52 increases. Therefore, the area of the facing surface 521 is, for example, 10 times or less the area of the facing surface 511. When viewed from above, the entire first electrode 51 overlaps the entire second electrode 52.

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

[0071] FIG. 10 is a view showing another example of the electrode unit, showing 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 direct injection nozzle facing the vertical direction, and in the state of being arranged at the processing position, the processing liquid nozzle 61 is arranged above the peripheral portion 93 of the substrate 9. The processing liquid nozzle 61 is formed of an insulating material such as resin, for example. The first electrode 51 of the electrode unit 5a is a film of a conductive material provided on the inner peripheral surface of the processing liquid nozzle 61. In other words, the processing liquid nozzle 61 is a nozzle with an internal electrode. Similar to the example of FIG. 9, the second electrode 52 is plate-shaped. A power supply 50 is connected to the first electrode 51 and the second electrode 52.

[0072] In the etching of the metal film 96 on the peripheral portion 93 of the substrate 9, the processing liquid L1 is continuously ejected from the ejection port 611 of the processing liquid nozzle 61. The processing liquid L1 covers the metal film 96 at the target portion of the peripheral portion 93 and collides with the second electrode 52. In other words, the liquid column of the processing liquid L1 formed downward from the ejection port 611 contacts both the target portion of the peripheral portion 93 and the second electrode 52. In fact, the processing liquid L1 also wraps around to the second main surface 92 side of the peripheral portion 93 and is also filled in the gap between the second electrode 52 and the peripheral portion 93. Thus, the liquid filling state in which the processing liquid L1 is filled between the target portion, the first electrode 51, and the second electrode 52 is maintained. A voltage is applied between the first electrode 51 and the second electrode 52 by the power supply 50, and the metal film 96 is etched. Further, by controlling the electrode moving mechanism 73 based on the warpage information, the change in the distance between the substrate 9 and the electrodes 51, 52 (particularly the change in the distance between the substrate 9 and the second electrode 52) can be suppressed, and the etching of the substrate 9 can be appropriately performed.

[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. In a state where 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 the opposing surface 511 facing the substrate 9, and is substantially parallel to the first main surface 91 of the substrate 9. The surface facing upward in the second electrode 52 is the opposing surface 521 facing the substrate 9, and is substantially parallel to the second main surface 92 of the substrate 9. The opposing surface 511 of the first electrode 51 and the opposing surface 521 of the second electrode 52 are substantially 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, a block formed of resin, and is disposed between the outer end portions of the first electrode 51 and 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 on the radially inner side of the insulating member 53. In the processing liquid pipeline 62 (refer to FIG. 2) of the processing liquid filling portion 6, a connecting member 622 is provided at the end portion on the side opposite to the processing liquid supply source 63, and the connecting member 622 is inserted into the above-mentioned through hole of the first electrode 51 and fixed. The connecting member 622 has a jet outlet 623 for the processing liquid L1, and the processing liquid L1 is supplied from the jet outlet 623 to the space 54 (hereinafter referred to as "processing space 54") surrounded by the insulating member 53, the first electrode 51, and the second electrode 52. In the substrate processing apparatus 1 of FIG. 11, the connecting member 622, the first electrode 51, the insulating member 53, and the second electrode 52 are integrally formed as one member. In the electrode moving mechanism 73, the auxiliary moving mechanism 711 (refer to FIG. 3) is omitted, and the electrode unit 5b is mounted on the arm portion 72.

[0075] When etching the peripheral portion 93 of the substrate 9, by disposing the electrode unit 5b and the connecting member 622 at the processing position, the peripheral portion 93 is inserted into the processing space 54 from the radially inner side. Further, the processing liquid L1 is ejected from the jet outlet 623 of the connecting member 622, and the processing space 54 is filled with the processing liquid L1. That is, a liquid filling 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, a voltage is applied between the first electrode 51 and the second electrode 52 by the power source 50, and the metal film 96 is etched. Further, by controlling the electrode moving mechanism 73 based on the warpage information by the control unit 19, the change in the distance between the substrate 9 and the electrodes 51, 52 can be suppressed, and the etching of the substrate 9 can be appropriately performed. In addition, if the liquid filling state is maintained in the processing space 54, the ejection of the processing liquid L1 from the jet outlet 623 can be either continuous or intermittent.

[0076] As described above, in the electrode unit 5b shown in FIG. 11, the insulating member 53 is provided. The insulating member 53 is disposed between the first electrode 51 and the second electrode 52 on the outer side of the peripheral portion 93 of the substrate 9, and fixes the first electrode 51 and the second electrode 52. The processing liquid filling portion 6 supplies the processing liquid L1 from the jet outlet 623 to the processing space 54 surrounded by the insulating member 53, the first electrode 51, and the second electrode 52. Thereby, a liquid filling state can be easily and more surely formed, and the etching of the metal film 96 of the peripheral portion 93 can be appropriately performed.

[0077] In the substrate processing apparatus 1, the substrate 9 does not necessarily have to be held in a horizontal posture. For example, the substrate 9 can be held in an upright state. When the substrate 9 is made upright in the substrate processing apparatus 1 of FIG. 11, the direction of the electrode unit 5b is changed (the state of rotating FIG. 11 clockwise by 90°) such that the insulating member 53 is disposed below the upright substrate 9. Further, in the electrode unit 5b of FIG. 11, it is feasible that the first electrode 51 is located on one main surface side of the substrate 9 (for example, the first main surface 91 side), and the second electrode 52 is located on the radially outer side of the substrate 9. Furthermore, in the electrode unit 5b, on one main surface side of the substrate 9 (for example, the first main surface 91 side), the first electrode 51, the insulating member 53, and the second electrode 52 can be arranged in a circumferential direction.

[0078] On the other hand, for increasing the etching rate of the metal film 96 in the peripheral portion 93, it is preferable that, like the electrode units 5, 5a, 5b in FIGS. 3, 9, 10, and 11, 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. Thus, by disposing the substrate 9 between the first electrode 51 and the second electrode 52, the etching of the metal film 96 can be performed efficiently. In the above electrode units 5, 5a, 5b, when observed in a direction perpendicular to the main surfaces 91, 92 of the substrate 9, substantially the entire first electrode 51 overlaps with the second electrode 52, but the first electrode 51 and the second electrode 52 can overlap only partially. In the substrate processing apparatus 1, when observed in a direction perpendicular to the two main surfaces 91, 92 of the substrate 9, by at least partial overlap of the first electrode 51 and the second electrode 52, the etching of the metal film 96 can be performed efficiently.

[0079] In the above substrate processing apparatus 1, in the circumferential direction, the first electrode 51 and the second electrode 52 are disposed at substantially the same position, but the first electrode 51 and the second electrode 52 can be arranged to be separated from each other. FIG. 12 is a view showing the substrate processing apparatus 1a of the second embodiment. In the substrate processing apparatus 1a, both the first electrode 51 and the second electrode 52 are disposed on the first main surface 91 side of the substrate 9. Specifically, in a state where the electrode unit 5c is disposed 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 separated from the first electrode 51 in the circumferential direction and is close to the substrate 9 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] Further, 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 side of the first main surface 91. The first processing liquid nozzle 61a is disposed near the first electrode 51 and sprays the processing liquid L1 between the first electrode 51 and the substrate 9. Through the processing liquid L1, the first electrode 51 is electrically connected to the metal film 96 on the peripheral portion 93. The second processing liquid nozzle 61b is disposed near the second electrode 52 and sprays the processing liquid L1 between the second electrode 52 and the substrate 9. Through the processing liquid L1, the second electrode 52 is electrically connected to the metal film 96 on the peripheral portion 93 at a position different from that of the first electrode 51. Thus, by the processing liquid filling unit 6, the processing liquid L1 is filled 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 the arm portion 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 portion 72, and moves the second electrode 52 and the second processing liquid nozzle 61b in the vertical direction.

[0082] During the etching of the substrate processing apparatus 1a, the substrate 9 is also rotated, and a voltage is applied between the first electrode 51 and the second electrode 52 by the power supply 50. In the example of FIG. 12, the first electrode 51 is the cathode and the second electrode 52 is the anode. Thereby, the metal film 96 on the peripheral portion 93 is etched. Further, based on the warpage information, the first electrode moving mechanism 73a and the second electrode moving mechanism 73b are controlled to keep the distance between each of the first electrode 51 and the second electrode 52 and the substrate 9 substantially constant. As a result, the etching of the substrate 9 can be appropriately performed. In addition, in FIG. 12, the illustration of the sensor 81 is omitted.

[0083] In the substrate processing apparatus 1a, etching can also be performed in a region inside the peripheral portion 93. On the other hand, since the warpage of the substrate 9 usually becomes larger at the peripheral portion 93, the above 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, preferably, similar to the above substrate processing apparatus 1, the electrode unit 5c disposed at the processing position faces the peripheral portion 93 of the substrate 9, and the warpage information indicates the warpage amount of the peripheral portion 93.

[0084] Now, in the substrate processing apparatus 1a, a metal film 96 is etched near the cathode, i.e., the first electrode 51. However, after the etching progresses to a certain extent, if the second electrode 52 (anode) faces the area where the metal film 96 has been removed, the second electrode 52 will not be electrically connected to the metal film 96. As a result, current does not flow between the first electrode 51 and the second electrode 52, and the etching stops progressing. Also, when the metal film 96 is scattered in the peripheral portion 93, current does not flow between the first electrode 51 and the second electrode 52, and the etching stops progressing.

[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 an object portion that is a part of the peripheral portion 93 of the substrate 9, and the processing liquid L1 is filled between the object portion, the first electrode 51, and the second electrode 52. Thereby, the first electrode 51 and the second electrode 52 are electrically connected to the metal film 96 of the object portion via the same processing liquid L1, i.e., substantially at one contact point. As a result, even in the case where there is an area where the metal film 96 has been removed and an isolated metal film 96, the etching of the metal film 96 can be appropriately performed. Also, in the substrate processing apparatus 1 that supplies the processing liquid L1 to only one portion on the peripheral portion 93, the consumption amount of the processing liquid L1 can be greatly reduced. In addition, according to the design of the substrate processing apparatus 1 of FIG. 2, in addition to the above-described processing liquid nozzle 61, another processing liquid nozzle that supplies the processing liquid L1 between the second electrode 52 and the substrate 9 can be provided to more surely form a liquid filling state.

[0086] The above-described substrate processing apparatuses 1 and 1a can be variously modified.

[0087] In the above-described embodiment, the warpage information of the substrate 9 is obtained by using the sensor 81 in the substrate processing apparatuses 1 and 1a, but the warpage information of the substrate 9 obtained by an external device can be input to the control unit 19 of the substrate processing apparatuses 1 and 1a. That is, in the control unit 19, the warpage information can be obtained by inputting the warpage information from the outside. For example, in the path portion 103 of the substrate processing system 10 of FIG. 1, a sensor R1 similar to the sensor 81 is provided (shown by a dashed line 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 portion 103 by an omission of a moving mechanism not shown. Thereby, in the substrate 9 before being carried into the substrate processing apparatuses 1 and 1a, warpage information indicating each angular position (for example, an angular position based on a notch) and the warpage amount of the peripheral portion 93 at that angular position is obtained. In the substrate processing apparatuses 1 and 1a, the electrode moving mechanism 73 is controlled based on the warpage information.

[0088] In the substrate processing apparatus 1 of FIG. 2, similar to the substrate processing apparatus 1a of FIG. 12, two electrode moving mechanisms for independently moving the first electrode 51 and the second electrode 52 can be provided.

[0089] The substrate holding unit that holds the substrate 9 and the rotating mechanism that rotates the substrate 9 can have a structure other than the chuck unit 21 and the rotating mechanism 22 of FIG. 2. For example, a plurality of rollers can be arranged circumferentially around the substrate 9, and the plurality of rollers are in contact with the edge end surface of the substrate 9 to hold the substrate 9, and a part of the rollers rotate, and the substrate 9 is rotated about the central axis J1.

[0090] The substrates processed in the substrate processing apparatuses 1 and 1a are not limited to semiconductor substrates, and can be glass substrates or other substrates.

[0091] The configurations of the above-described embodiments and various variations can be appropriately combined as long as they do not contradict each other.

[0092] Although the invention has been described in detail, the above description is illustrative and not restrictive. Therefore, it can be said that as long as it does not depart from the scope of the present invention, a number of variations and aspects can be adopted.

[0093] 1, 1a: Substrate processing apparatus 2: Spin chuck 3: Cleaning liquid supply unit 4: Cup unit 5, 5a~5c: Electrode unit 6: Processing liquid filling unit 7: Electrode moving unit 9: Semiconductor substrate / Substrate 10: Substrate processing system 11: Housing 12: Airflow forming unit 19: Control unit 21: Chuck unit 22: Rotating mechanism 31: Cleaning liquid nozzle 32: Cleaning liquid supply source 41: Cup 50: Power supply 51: First electrode / Electrode 52: Second electrode / Electrode 53: Insulating member 54: Space / Processing space 61: Processing liquid nozzle 61a: First processing liquid nozzle 61b: Second processing liquid nozzle 62: Processing liquid pipeline 63: Processing liquid supply source 71: Support part 72, 821: Arm part 73: Electrode moving mechanism 73a: First electrode moving mechanism 73b: Second electrode moving mechanism 81: Sensor 82: Sensor moving part 91, 92: Main surface (of the substrate) 93: Peripheral part (of the substrate) 96: Metal film 101: Indexer block 102: Processing block 103: Path part 104: Carrier holding part 105: Indexer robot 106: IR moving mechanism 107: Carrier 108: Processing unit 109: Central robot 221: Axis 222: Motor 321, 621: Valve 511, 521: Surface / opposite surface 611, 623: Nozzle outlet 622: Connection member 710: Support part body 711: Auxiliary moving mechanism 822: Sensor moving mechanism J1: Central axis L1: Processing liquid P: Measurement point R1: Sensor S11~S18: Hold

Claims

1. A substrate processing apparatus for etching a metal film on a substrate, comprising: a substrate holding section for holding a circular substrate; a rotation mechanism for rotating the substrate together with the substrate holding section; an electrode unit having a first electrode and a second electrode, disposed at a processing position opposite to the substrate during etching; a processing liquid filling section for filling a processing liquid between the first electrode, the second electrode and the substrate; a power supply for applying a voltage between the first electrode and the second electrode; an electrode moving mechanism for moving the first electrode and the second electrode in a direction perpendicular to the main surface of the substrate; and a control unit for obtaining warpage information of the substrate based on measurement results from a sensor, and controlling the electrode moving mechanism based on the rotation angle of the substrate input from the rotation mechanism and the warpage information during etching.

2. The substrate processing apparatus of claim 1, wherein the aforementioned sensor measures the position of the aforementioned substrate in a direction perpendicular to the main surface of the aforementioned substrate at a predetermined position in the circumferential direction; and by inputting the measured value of the aforementioned sensor into the aforementioned control unit, the aforementioned warping information is obtained in the aforementioned control unit.

3. The substrate processing apparatus of claim 2, wherein the control unit performs the etching after rotating the substrate by the aforementioned rotating mechanism and obtaining the aforementioned warpage information by the aforementioned sensor.

4. The substrate processing apparatus of claim 3, wherein the position of the electrode unit disposed at the aforementioned processing position in the circumferential direction of the aforementioned substrate is the same as the position of the measurement point of the aforementioned sensor on the aforementioned substrate.

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

6. The substrate processing apparatus of any one of claims 1 to 5, wherein the electrode unit disposed at the aforementioned processing position faces the peripheral portion of the aforementioned substrate, and the aforementioned warpage information indicates the amount of warpage of the aforementioned peripheral portion.

7. The substrate processing apparatus of claim 6, wherein the electrode unit disposed at the aforementioned processing position faces a portion of the aforementioned peripheral portion that becomes the target area for the aforementioned etching; and the aforementioned processing liquid is ejected from the spray outlet by the aforementioned processing liquid filling section, thereby forming a liquid-filled state in which the aforementioned processing liquid is filled between the aforementioned target area, the aforementioned first electrode and the aforementioned second electrode.

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

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