Substrate processing apparatus

Abstract

The present invention relates to a substrate processing apparatus. A ceiling plate spans the entire upper surface of a substrate and faces the upper surface of the substrate in the vertical direction. A partition plate nozzle is fixed to the ceiling plate and sprays a processing liquid toward the upper surface of the substrate from the lower surface of the ceiling plate. A movable nozzle sprays a processing liquid toward the upper surface of the substrate from above the substrate. A nozzle moving mechanism moves the movable nozzle horizontally above the substrate. A second electrode provided on the lower surface of the ceiling plate is electrically connected to the processing liquid by directly contacting the liquid film formed in the gap between the lower surface of the ceiling plate and the upper surface of the substrate. A third electrode is electrically connected to the processing liquid sprayed from the movable nozzle.

Description

[0001] [Reference to relevant applications] This application claims priority based on Japanese Patent Application JP2025-074556 filed on April 28, 2025, the entire contents of which are disclosed in that application and are incorporated herein by reference. Technical Field

[0002] This invention relates to a technique for etching a substrate. Background Technology

[0003] In the past, various processes were performed on semiconductor substrates (hereinafter referred to as "substrate") during the fabrication process. For example, wet etching is performed in the substrate fabrication process, that is, an etching solution is supplied to the substrate to remove the film on the substrate. It is known that in this wet etching, the etching rate of the film in the micro-recesses such as trenches and holes on the substrate is low.

[0004] Therefore, Japanese Patent Application Publication No. 2020-155614 (Document 1) proposes a technique in which a conductive etching solution is supplied to a substrate, and a fixed-magnitude direct current is applied between the etching solution and the substrate, thereby allowing the conductive components of the etching solution to rapidly enter the gaps within the microstructures. Furthermore, International Patent Publication No. 2021 / 192502 (Document 2) proposes a technique in which an alternating voltage of 0.1 kHz or 1 kHz is applied to a pair of electrodes positioned between a substrate in contact with the etching solution, thereby increasing the etching rate.

[0005] However, in the substrate processing apparatus of Reference 1, the electrode used for etching is brought into contact with the central portion of the liquid film formed on the entire upper surface of the substrate. Therefore, the distance from the electrode varies depending on its position on the substrate, which may result in differences in the etching rate. Similarly, in the substrate processing apparatus of Reference 2, the processing liquid is stored in a frame placed on the upper surface of the substrate, and the electrode is brought into contact with the central portion of the processing liquid. Therefore, similar to Reference 1, differences in the etching rate may occur due to differences in the electrode's position on the substrate. Summary of the Invention

[0006] The present invention relates to a substrate processing apparatus for etching a substrate, with the aim of improving the uniformity of etching.

[0007] Embodiment 1 of the present invention is a substrate processing apparatus for etching a substrate, comprising: a substrate holding section for holding a substrate having a film to be processed on its upper surface in a horizontal state; a substrate rotating mechanism for rotating the substrate holding section about a central axis in the vertical direction; a processing liquid supply section for supplying processing liquid for etching to the upper surface of the substrate and bringing it into contact with the film to be processed; a partition plate spanning the entire upper surface of the substrate and facing the upper surface of the substrate in the vertical direction; a partition plate moving mechanism for moving the partition plate relative to the substrate in the vertical direction; a first electrode electrically connected to the substrate; a second electrode and a third electrode electrically connected to the processing liquid; and a power supply section capable of applying voltages between the first electrode and the second electrode, and between the first electrode and the third electrode, respectively. The processing liquid supply unit includes: a partition plate nozzle fixed to the partition plate, which sprays the processing liquid from the lower surface of the partition plate onto the upper surface of the substrate; a movable nozzle that sprays the processing liquid from above the substrate toward the upper surface of the substrate; and a nozzle moving mechanism that moves the movable nozzle horizontally above the substrate. When the gap between the lower surface of the partition plate and the upper surface of the substrate is filled with the processing liquid to form a liquid film, the second electrode disposed on the lower surface of the partition plate is electrically connected to the processing liquid through direct contact with the liquid film. The third electrode is electrically connected to the processing liquid sprayed from the movable nozzle.

[0008] According to the present invention, the uniformity of etching can be improved.

[0009] Embodiment 2 of the present invention is a substrate processing apparatus of Embodiment 1, further comprising: a control unit for controlling the substrate rotation mechanism, the processing liquid supply unit, the partition plate moving mechanism, and the power supply unit. Under the control of the control unit, with a liquid film of the processing liquid supplied from the partition plate nozzle formed in the gap between the lower surface of the partition plate and the upper surface of the substrate, a voltage is applied between the first electrode and the second electrode, thereby performing overall etching on the entire upper surface of the substrate. Under the control of the control unit, with the partition plate retracted above the substrate and the movable nozzle positioned radially at a desired position above the rotating substrate, the processing liquid is ejected from the movable nozzle, and simultaneously, a voltage is applied between the first electrode and the third electrode, thereby performing localized etching on a portion of the upper surface of the substrate.

[0010] The third aspect of the present invention is a substrate processing apparatus of aspect 2, wherein the partial etching is performed after the overall etching of the substrate is performed under the control of the control unit.

[0011] The fourth embodiment of the present invention is a substrate processing apparatus of the second embodiment (or the third embodiment), wherein the local etching is performed on the radial central portion of the substrate.

[0012] The fifth aspect of the present invention is a substrate processing apparatus of aspect 2 (or any of aspects 2 to 4), wherein the local etching is performed on the periphery of the substrate.

[0013] Embodiment 6 of the present invention is a substrate processing apparatus of Embodiment 2 (or any of Embodiments 2 to 5), wherein the third electrode is a plate-shaped component mechanically connected to the lower end of the movable nozzle, facing the upper surface of the substrate in the vertical direction, and smaller than the upper surface of the substrate. The local etching is performed with a liquid film formed in the gap between the lower surface of the third electrode and the upper surface of the substrate filled with the processing liquid.

[0014] Embodiment 7 of the present invention is a substrate processing apparatus of Embodiment 2 (or any one of Embodiments 2 to 6), further comprising: a heating unit disposed on the substrate holding unit, which heats the substrate from below. The heating unit is capable of varying the amount of heat applied to the lower surface of the substrate per unit area according to the distance between itself and the center of the substrate.

[0015] Embodiment 8 of the present invention is a substrate processing apparatus of any of Embodiments 2 to 7, wherein, in at least one of the overall etching and the partial etching, the voltage applied between the first electrode and the second electrode or the third electrode repeatedly switches between different first voltages and second voltages at a predetermined switching cycle, thereby repeatedly switching the potential of the sidewall surface of the recess forming the pattern on the substrate between a first potential and a second potential less than the first potential. The first potential is 0 V or more. The second potential is 0 V or less.

[0016] The 9th embodiment of the present invention is the substrate processing apparatus of the 8th embodiment, wherein the switching cycle is 0.05 seconds or more.

[0017] The objectives, other objectives, features, forms, and advantages of the present invention are set forth in the following detailed description with reference to the accompanying drawings. Attached Figure Description

[0019] Figure 1 This is a top view of the substrate processing system.

[0020] Figure 2 This is a side view of a substrate processing apparatus according to one embodiment.

[0021] Figure 3 It is a diagram showing an enlarged view of the area near the clamping pin.

[0022] Figure 4 It is a cross-sectional view that is magnified and represents a portion of the substrate.

[0023] Figure 5 This is a diagram showing the substrate processing flow.

[0024] Figure 6 This is a side view of the substrate processing apparatus.

[0025] Figure 7 This is a side view of the substrate processing apparatus.

[0026] Figure 8A It is a diagram showing the waveform of the applied voltage.

[0027] Figure 8B It is a diagram showing the waveform of the applied voltage.

[0028] Figure 9A It is a cross-sectional view that is magnified and represents a portion of the substrate.

[0029] Figure 9B It is a cross-sectional view that is magnified and represents a portion of the substrate.

[0030] Figure 9C It is a cross-sectional view that is magnified and represents a portion of the substrate.

[0031] Figure 9D It is a cross-sectional view that is magnified and represents a portion of the substrate.

[0032] Figure 10A It is a cross-sectional view that is magnified and represents a portion of the substrate.

[0033] Figure 10B It is a cross-sectional view that is magnified and represents a portion of the substrate.

[0034] Figure 10C It is a cross-sectional view that is magnified and represents a portion of the substrate.

[0035] Figure 10D It is a cross-sectional view that is magnified and represents a portion of the substrate.

[0036] Figure 11 This is a side view of the substrate processing apparatus.

[0037] Figure 12 This is a diagram showing the experimental setup.

[0038] Figure 13 It is a cross-sectional view that is magnified and represents a portion of the substrate.

[0039] Figure 14 This is a side view of another substrate processing device.

[0040] Figure 15 This is a side view of another substrate processing device.

[0041] Figure 16 This is a side view of another substrate processing device. Detailed Implementation

[0042] Figure 1 This is a schematic top view showing the layout of the substrate processing system 10. The substrate processing system 10 is a system for processing a semiconductor substrate 9 (hereinafter simply referred to as "substrate 9"). The substrate processing system 10 includes a transfer module 101 and a processing module 102 coupled to the transfer module 101.

[0043] The transfer module 101 includes a carrier holding section 104, a transfer robot 105, and an IR moving mechanism 106. The carrier holding section 104 holds multiple carriers 107 capable of accommodating multiple substrates 9. The multiple carriers 107 (e.g., FOUP) are held in the carrier holding section 104 in a state arranged along a predetermined carrier arrangement direction. The IR moving mechanism 106 moves the transfer robot 105 along the carrier arrangement direction. The transfer robot 105 performs a removal action to take the substrate 9 out of the carrier 107 and a loading action to load the substrate 9 into the carrier 107 held in the carrier holding section 104. The transfer robot 105 transfers the substrate 9 in a horizontal posture.

[0044] The processing module 102 includes multiple (e.g., four or more) processing units 108 for processing substrate 9, and a central robot 109. The multiple processing units 108 are arranged to surround the central robot 109 in a top-view configuration. Various processes are performed on the substrate 9 within the multiple processing units 108. The substrate processing apparatus described below is one of the multiple processing units 108. The central robot 109 performs a loading action to load the substrate 9 into the processing units 108 and a unloading action to remove the substrate 9 from the processing units 108. Furthermore, the central robot 109 transports the substrate 9 between the multiple processing units 108. The substrate 9 is transported horizontally by the central robot 109. The central robot 109 receives the substrate 9 from the transfer robot 105 and also delivers the substrate 9 to the transfer robot 105.

[0045] Figure 2 This is a side view showing the configuration of a substrate processing apparatus 1 according to an embodiment of the present invention. The substrate processing apparatus 1 is a monolithic apparatus for processing substrates 9 one by one. The substrate processing apparatus 1 is an apparatus for etching a film to be processed provided on the upper main surface (hereinafter also referred to as "upper surface 91") of the substrate 9. Figure 2 In the image, a portion of the substrate processing apparatus 1 is shown in cross-section.

[0046] The substrate processing apparatus 1 includes a substrate holding section 21, a substrate rotation mechanism 23, a partition section 3, a cup section 4, a processing liquid supply section 5, a voltage application section 6, a housing 11, and a control section 8. The substrate holding section 21, substrate rotation mechanism 23, partition section 3, and cup section 4 are housed within the internal space of the housing 11. An airflow forming section 12 is provided on the top cover of the housing 11 to supply gas to the internal space, forming a downward airflow (so-called downflow). For example, an FFU (fan filter unit) is used as the airflow forming section 12. The control section 8 is located outside the housing 11 and controls the substrate holding section 21, substrate rotation mechanism 23, partition section 3, processing liquid supply section 5, and voltage application section 6.

[0047] The control unit 8 is, for example, a general-purpose computer system including a CPU, ROM, RAM, hard disk, display, input unit, reading device, communication unit, and bus. The processor, such as the CPU, executes calculations and other processing according to instructions stored in memory such as ROM, RAM, and hard disk. The control unit 8 includes a power control unit 81 and an operation control unit 82 to perform the functions implemented by the processor. The power control unit 81 controls the power supply unit 66 (described below) of the voltage application unit 6. The operation control unit 82 controls the processing liquid supply unit 5 and the substrate rotation mechanism 23, etc. Alternatively, the control unit 8 can also be a programmable logic controller (PLC) or a circuit board. The control unit 8 can also include any combination of components such as a computer system, a PLC, and a circuit board.

[0048] The substrate holding part 21 and the substrate rotating mechanism 23 are both parts of a rotating chuck that holds and rotates a generally circular substrate 9. The substrate holding part 21 supports the horizontally positioned substrate 9 from below. Figure 2 The substrate holding section 21 shown is a mechanical clamp that holds the substrate 9 mechanically.

[0049] The substrate holding portion 21 includes a base portion 211, a plurality of (e.g., 4 or 6) clamping pins 212, and a shaft 217. The base portion 211 is a generally circular plate-shaped component centered on a central axis J1 pointing vertically. The substrate 9 is disposed above the base portion 211, separated from it. In other words, the base portion 211 of the substrate holding portion 21 faces the lower surface 92 (hereinafter also referred to as "lower surface 92") vertically, separated from the lower side main surface of the substrate 9. The diameter of the base portion 211 is slightly larger than the diameter of the substrate 9. The shaft 217 is a generally cylindrical or generally cylindrical component centered on the central axis J1. The shaft 217 extends vertically and is connected to the center of the lower surface of the base portion 211.

[0050] In the substrate holding portion 21, a plurality of clamping pins 212 are arranged circumferentially (hereinafter also simply referred to as "circumferential") around the central axis J1 and erected on the outer periphery of the upper surface of the base portion 211. The plurality of clamping pins 212 are located at approximately the same position radially (hereinafter also simply referred to as "radial") around the central axis J1. In other words, the plurality of clamping pins 212 are located on approximately the same circumference around the central axis J1. The plurality of clamping pins 212 are arranged, for example, at approximately equal angular intervals in the circumferential direction. The plurality of clamping pins 212 contact the periphery of the substrate 9 to hold the substrate 9.

[0051] Figure 3 This is an enlarged view of the area near a clamping pin 212 on the base portion 211. The shape of the plurality of clamping pins 212 is similar to... Figure 3 The illustrated shapes are generally the same. The radially inner side surface of the upper part of the clamping pin 212 (hereinafter also referred to as "upper inner side surface 213") is in direct contact with the periphery of the substrate 9. In the clamping pin 212, the central portion 214 of the upper inner side surface 213 in the vertical direction is recessed radially outward. In other words, the central portion 214 of the upper inner side surface 213 of the clamping pin 212 is located radially outward compared to the upper portion 215 above the central portion 214 and the lower portion 216 below the central portion 214. When the substrate 9 is held by the substrate holding portion 21, the upper portion 215 of the upper inner side surface 213 of the clamping pin 212 is in direct contact with the periphery of the upper surface 91 of the substrate 9, and the lower portion 216 of the upper inner side surface 213 of the clamping pin 212 is in direct contact with the periphery of the lower surface 92 of the substrate 9.

[0052] like Figure 2 As shown, the substrate rotation mechanism 23 is disposed inside the cover portion 24 located below the substrate holding portion 21. The cover portion 24 is a covered, generally cylindrical component centered on the central axis J1. The upper surface of the cover portion 24 is separated from the lower surface of the base portion 211 and faces each other in the vertical direction. A small gap is provided between the upper surface of the cover portion 24 and the lower surface of the base portion 211.

[0053] The substrate rotation mechanism 23 rotates the substrate 9 together with the substrate holding portion 21 around a central axis J1 that extends substantially parallel to the vertical direction. The substrate rotation mechanism 23 includes a motor 232. The motor 232 is an electric rotary motor that rotates the shaft 217 of the substrate holding portion 21. Alternatively, the substrate rotation mechanism 23 may also be a motor with other structures (e.g., a hollow motor).

[0054] The partition 3 includes a top plate 31, a top plate rotation mechanism 32, and a top plate movement mechanism 33. The top plate 31 is a generally circular plate-shaped component centered on a central axis J1. The top plate 31 is positioned above the substrate 9 held by the substrate holding part 21, separated upward from the upper surface 91 of the substrate 9. The diameter of the top plate 31 is slightly larger than the diameter of the substrate 9. The lower surface 311 of the top plate 31 spans approximately the entire upper surface 91 of the substrate 9 and faces the upper surface 91 in the vertical direction. The top plate 31 is an opposing component facing the upper surface 91 of the substrate 9 in the vertical direction, and is a partition plate that disconnects the space above the substrate 9 from the surrounding space.

[0055] A top plate rotation mechanism 32 is disposed above the top plate 31. The top plate rotation mechanism 32 causes the top plate 31 to rotate about a central axis J1. The top plate rotation mechanism 32 includes a shaft 321 and a motor 322. The shaft 321 is a generally cylindrical component centered on the central axis J1. The shaft 321 extends vertically and is connected to the center of the upper surface of the top plate 31. The motor 322 is an electric rotary motor that rotates the shaft 321. Alternatively, the top plate rotation mechanism 32 may be a motor with other structures (e.g., a hollow motor).

[0056] The top plate moving mechanism 33 is a partition plate moving mechanism that moves the top plate 31 above the substrate 9 in a vertical direction. The top plate moving mechanism 33 can be, for example, a ball screw and an electric rotary motor connected to the shaft 321 via an arm 34 extending in a generally horizontal direction. The top plate moving mechanism 33 can also be an electric linear motor or a cylinder, etc. Furthermore, the top plate moving mechanism 33 can also move the top plate 31 relative to the substrate 9 in a vertical direction by moving the substrate holding part 21 in a vertical direction.

[0057] The processing liquid supply unit 5 supplies processing liquid to the substrate 9. The processing liquid supply unit 5 includes a partition plate nozzle 51 and a movable nozzle 52. The partition plate nozzle 51 is a generally cylindrical tubular component that extends approximately parallel to the vertical direction with the central axis J1 as the center. The partition plate nozzle 51 is fixed relative to the top plate 31 and is located above the substrate 9, at a position separated from the upper surface 91 of the substrate 9.

[0058] Specifically, the partition plate nozzle 51 is disposed inside the shaft 321 of the top plate rotation mechanism 32. When the shaft 321 is rotated by the motor 322 of the top plate rotation mechanism 32, the partition plate nozzle 51 remains stationary independently of the rotation of the shaft 321. Alternatively, the partition plate nozzle 51 may also rotate together with the shaft 321. Figure 2In the example shown, the lower end of the partition plate nozzle 51 is located at approximately the same position as the lower surface 311 of the top plate 31 in the vertical direction. The nozzle outlet located at the lower end of the partition plate nozzle 51 is located at the opening provided in the center of the lower surface 311 of the top plate 31, and is opposite to the center of the upper surface 91 of the substrate 9 (i.e., the radial center) in the vertical direction.

[0059] The partition plate nozzle 51 can spray processing liquid from the nozzle outlet at its lower end onto the upper surface 91 of the substrate 9. That is, the partition plate nozzle 51 can spray processing liquid from the lower surface 311 of the top plate 31 onto the upper surface 91 of the substrate 9. The processing liquid sprayed from the partition plate nozzle 51 contacts the film to be processed disposed on the upper surface 91 of the substrate 9. Furthermore, the lower end of the partition plate nozzle 51 can be located either below or above the lower surface 311 of the top plate 31.

[0060] The movable nozzle 52 is a generally cylindrical tubular component extending substantially parallel to the vertical direction. The movable nozzle 52 is supported by a generally horizontally extending arm 53 and is positioned above the substrate 9, separated from the upper surface 91 of the substrate 9. The movable nozzle 52 can eject a processing liquid from an outlet located at its lower end toward the upper surface 91 of the substrate 9. The processing liquid ejected from the movable nozzle 52 contacts the film to be processed on the upper surface 91 of the substrate 9. The processing liquid ejected from the movable nozzle 52 is the same type of liquid as the processing liquid ejected from the partition plate nozzle 51.

[0061] The movable nozzle 52 is connected to a supply source (not shown) for conveying the processing liquid or the like via a piping 521. The piping 521 is, for example, a flexible tubular component. The processing liquid or the like conveyed from the supply source is guided to the movable nozzle 52 via the piping 521 and, as described above, is ejected from the movable nozzle 52 onto the upper surface 91 of the substrate 9.

[0062] The end of arm 53 opposite to the movable nozzle 52 is connected to nozzle moving mechanism 55. Nozzle moving mechanism 55 moves the movable nozzle 52 horizontally above substrate 9 by rotating arm 53 horizontally. Nozzle moving mechanism 55 can, for example, move the movable nozzle 52 between a position above substrate 9 and a retracted position radially outward from the periphery of substrate 9. Additionally, nozzle moving mechanism 55 can also position the movable nozzle 52 at a desired radial position above substrate 9. Furthermore, nozzle moving mechanism 55 raises and lowers the movable nozzle 52 by moving arm 53 vertically. Nozzle moving mechanism 55 can be, for example, a ball screw and an electric rotary motor. Nozzle moving mechanism 55 can also be an electric rotary motor, an electric linear motor, or a cylinder, etc.

[0063] The processing liquid supplied from the partition nozzle 51 and the movable nozzle 52 to the upper surface 91 of the substrate 9 is, for example, a liquid (i.e., an etching solution) used to etch the film to be processed disposed on the upper surface 91 of the substrate 9. This processing liquid is generally conductive. The etching solution contains etchants such as hydrogen peroxide (H2O2), hydrofluoric acid (HF), nitric acid (HNO3), ammonia (NH3), TMAH (tetramethylammonium hydroxide), or TBAH (tetrabutylammonium hydroxide).

[0064] The partition plate nozzle 51 and the movable nozzle 52 can also spray a processing liquid (i.e., a rinsing liquid) for rinsing the upper surface 91 of the substrate 9. DIW (deionized water) or similar solutions can be used as the rinsing liquid. Furthermore, the partition plate nozzle 51 and the movable nozzle 52 can also spray processing liquids other than etching solutions and rinsing liquids, and / or inactive gases such as nitrogen (N2).

[0065] The cup portion 4 includes a cup 41 and a cup lifting mechanism (not shown in the figure). The cup 41 is an annular component centered on the central axis J1. The cup 41 is arranged across the entire circumference of the substrate 9 and the substrate holding portion 21, covering the sides and bottom of the substrate 9 and the substrate holding portion 21. The cup 41 is a liquid receiving container for receiving liquids such as processing liquid that are scattered from the rotating substrate 9. The inner surface of the cup 41 is formed, for example, by a water-repellent material. The cup 41 remains stationary in the circumferential direction regardless of whether the substrate 9 is rotating or stationary. At the bottom of the cup 41, a drain port (not shown in the figure) is provided for discharging the processing liquid or the like received in the cup 41 to the outside of the outer casing 11.

[0066] The cup-holding lifting mechanism causes the cup 41 to move vertically relative to the substrate holding part 21. The cup-holding lifting mechanism can be, for example, an electric linear motor, a cylinder, or a ball screw and electric rotary motor connected to the cup 41. Through the cup-holding lifting mechanism, the cup 41 can... Figure 2 The processing position shown is located around the substrate 9 and moves vertically between the processing position and the retreat position located below the processing position.

[0067] The cup portion 4 may also have multiple cups 41 stacked radially. When the cup portion 4 has multiple cups 41, the multiple cups 41 can move independently in the vertical direction, and the multiple cups 41 can be switched to receive the processing liquid depending on the type of processing liquid that is dispersed from the substrate 9.

[0068] The voltage application unit 6 includes a first electrode 61, a second electrode 62, a third electrode 63, a power supply unit 66, a first transmission unit 64, and a second transmission unit 65. The first electrode 61 is provided on each clamping pin 212 of the substrate holding unit 21. Specifically, as shown... Figure 3As shown, the first electrode 61 is a generally plate-shaped conductive component disposed on the upper inner surface 213 of the clamping pin 212. The radially inner surface of the first electrode 61 protrudes from the upper inner surface 213 of the clamping pin 212 and is not covered by the clamping pin 212.

[0069] The first electrode 61 is disposed on the upper inner side 213 of the clamping pin 212, spanning the upper part 215, the central part 214 and the lower part 216 of the upper inner side 213. The first electrode 61 is electrically connected to the substrate 9 by directly contacting the peripheral part of the substrate 9. Figure 3 In the example shown, the first electrode 61 is located at the periphery of the substrate 9, in direct contact with both the upper surface 91 and the lower surface 92 of the substrate 9. In each clamping pin 212, the surface of the portion other than the first electrode 61 is formed of, for example, an insulator. This surface may also be formed of a conductor.

[0070] The second electrode 62 is disposed on the lower surface 311 of the top plate 31. The lower surface 621 of the second electrode 62 protrudes from the lower surface 311 of the top plate 31 and is not covered by the top plate 31. The second electrode 62 is, for example, a generally annular plate-shaped conductive component centered on a central axis J1. In top view (i.e., viewed parallel to the vertical direction), the outer diameter of the second electrode 62 is slightly smaller than the outer diameter of the top plate 31 and is approximately the same as the diameter of the substrate 9. Furthermore, in a plane, the outer diameter of the second electrode 62 may be smaller or larger than the diameter of the substrate 9. The lower surface 621 of the second electrode 62 spans approximately the entire upper surface 91 of the substrate 9 and faces the upper surface 91 in the vertical direction. The lower surface 621 of the second electrode 62 is a plane that is approximately parallel to the upper surface 91 of the substrate 9.

[0071] As described below, during etching of the upper surface 91 of the substrate 9, the top plate 31 is close to the upper surface 91 of the substrate 9, and a liquid film of the etching solution is formed in the gap between the lower surface 311 of the top plate 31 and the upper surface 91 of the substrate 9. The second electrode 62 is electrically connected to the etching solution by direct surface contact with the liquid film.

[0072] The second electrode 62 and the plurality of first electrodes 61 respectively disposed on the plurality of clamping pins 212 are formed of materials with high chemical resistance and electrical conductivity. The second electrode 62 and each of the first electrodes 61 are, for example, formed of platinum (Pt) or glassy carbon (GC). In addition, the shape and material of each of the first electrodes 61 and the second electrode 62 can be varied.

[0073] The third electrode 63 is electrically connected to the treatment liquid ejected from the movable nozzle 52. Figure 2In the example shown, the third electrode 63 is disposed inside the movable nozzle 52 and is in direct contact with the processing liquid flowing through the flow path inside the movable nozzle 52, and is electrically connected to the processing liquid. Thus, the third electrode 63 is electrically connected to the processing liquid ejected from the movable nozzle 52 before the processing liquid exits the movable nozzle 52. The third electrode 63 is formed of a material with high chemical resistance and electrical conductivity. For example, the third electrode 63 is formed of platinum (Pt) or glassy carbon (GC). Furthermore, the material and arrangement of the third electrode 63 can be varied.

[0074] The third electrode 63 does not necessarily need to be located inside the movable nozzle 52. For example, if the movable nozzle 52 is made of a highly conductive material such as glassy carbon, the third electrode 63 may be disposed in direct contact with the surface of the movable nozzle 52. In this way, the third electrode 63 and the treatment liquid ejected from the movable nozzle 52 are electrically connected via the movable nozzle 52 before the treatment liquid is ejected from the movable nozzle 52.

[0075] Alternatively, if the piping 521 is a conductive pipe such as an AS (Anti-Static) pipe, the third electrode 63 can also be disposed in direct contact with the surface of the piping 521. Thus, the third electrode 63 and the treatment liquid ejected from the movable nozzle 52 are electrically connected via the piping 521 before the treatment liquid is ejected from the movable nozzle 52. Various changes can be made to the materials of the movable nozzle 52 and the piping 521.

[0076] Furthermore, if the movable nozzle 52 and the piping 521 are conductive, the third electrode 63 can be electrically connected to at least one of the movable nozzle 52 and the piping 521. Alternatively, if the movable nozzle 52 is conductive, the movable nozzle 52 can also be used as the third electrode 63. Additionally, if the piping 521 is conductive, the piping 521 can also be used as the third electrode 63.

[0077] The power supply unit 66 is electrically connected to the first electrode 61, the second electrode 62, and the third electrode 63. The power supply unit 66 is capable of applying a voltage between the first electrode 61 and the second electrode 62. Additionally, the power supply unit 66 is capable of applying a voltage between the first electrode 61 and the third electrode 63. In the following description, the voltage applied between the first electrode 61 and the second electrode 62 via the power supply unit 66, and the voltage applied between the first electrode 61 and the third electrode 63 via the power supply unit 66, are respectively referred to as the "applied voltage". For example, a power supply capable of applying both DC and AC voltages can be used as the power supply unit 66. The power supply unit 66 is controlled by the power control unit 81 of the control unit 8.

[0078] The power supply unit 66 is mechanically and electrically connected to the third electrode 63 via a wire. Additionally, the power supply unit 66 is mechanically and electrically connected via a wire to a slip ring (not shown) located at the shaft 321 of the top plate rotation mechanism 32, and via this slip ring, is electrically connected to the second electrode 62 located on the top plate 31. Furthermore, in Figure 2 In order to simplify the diagram, the power supply unit 66 and the second electrode 62 are directly connected by a wire.

[0079] Figure 2 In the example shown, the power supply unit 66 is electrically connected to each of the first electrodes 61 via the second transmission unit 65 and the first transmission unit 64. The first transmission unit 64 is provided in the base portion 211 of the substrate holding portion 21. Specifically, the first transmission unit 64 is disposed inside the base portion 211, for example, near the lower surface of the base portion 211. The first transmission unit 64 rotates with the substrate holding portion 21 when the substrate holding portion 21 rotates. The first transmission unit 64 is a generally annular plate-shaped receiving substrate centered on the central axis J1. A receiving coil is provided on the lower surface of the first transmission unit 64, and circuit components for receiving electricity are mounted on the upper surface of the first transmission unit 64. The first transmission unit 64 is mechanically and electrically connected to each of the first electrodes 61 via wires disposed inside the base portion 211.

[0080] The second transmission section 65 is located inside the cover section 24, near the upper surface of the cover section 24. That is, the second transmission section 65 is arranged downwards, separated from the base section 211 of the substrate holding section 21. The second transmission section 65 remains stationary independently of the rotation of the substrate holding section 21 when the substrate holding section 21 rotates. The second transmission section 65 is, for example, a generally annular plate-shaped power transmission substrate centered on a central axis J1. The second transmission section 65 is separated from the first transmission section 64 and faces each other in the vertical direction. The shape of the second transmission section 65 in plan view is, for example, substantially the same as the shape of the first transmission section 64 in plan view. A power transmission coil is provided on the upper surface of the second transmission section 65, and circuit components for power transmission are mounted on the lower surface of the second transmission section 65. The second transmission section 65 is mechanically and electrically connected to the power supply section 66 via wires.

[0081] When a voltage is applied between the first electrode 61 and the second electrode 62, or between the first electrode 61 and the third electrode 63, via the power supply unit 66, the transmitting coil of the second transmission unit 65 is magnetically coupled to the receiving coil of the first transmission unit 64, and power is transmitted from the second transmission unit 65 to the first transmission unit 64 in a contactless manner. That is, the first transmission unit 64 and the second transmission unit 65 are magnetically coupled wireless feeding elements. Furthermore, the shape, structure, and arrangement of the first transmission unit 64 and the second transmission unit 65 can be varied. For example, the first transmission unit 64 and the second transmission unit 65 can also be electric field coupled wireless feeding elements.

[0082] Figure 4 This is a cross-sectional view showing an enlarged portion of substrate 9. Figure 4 In the example shown, two of the many microstructures 94 constituting the micropattern (hereinafter also referred to as "micropattern 93") disposed on the surface of the substrate 9 are shown. The microstructure 94 is a microstructure disposed on the upper surface of the substrate body formed of silicon (Si), for example, it can be a structure formed of a single material or a multilayer structure formed by stacking multiple materials.

[0083] The microstructure 94 is, for example, a nanosheet channel with a GAA (Gate All Around) structure, and the recess 95 is a trench between these nanosheet channels. The processed film 96 is a metal gate electrode material in an RMG (Replacement Metal Gate). The sidewall surface 942 of the microstructure 94 forming the recess 95 (i.e., the inner surface of the recess 95) is formed, for example, from a High-k material (high dielectric constant material) with a higher dielectric constant than SiO2 (silicon dioxide). Hafnium-based, tungsten-based, or cobalt-based materials can be used as the High-k material.

[0084] The two microstructures 94 are along with Figure 4 The paper extends in a roughly straight line in a direction approximately perpendicular to the surface (hereinafter also referred to as the "length direction"). That is, in Figure 4 The image shows a longitudinal section of two microstructures 94, and also shows a longitudinal section of a micro-gap, i.e., a recess 95, provided between the two microstructures 94.

[0085] The width direction of the recess 95 perpendicular to the length direction (i.e., Figure 4 The width (in the vertical direction) is, for example, less than 10 nm. Figure 4 The depth of the recess 95 in the left-right direction is, for example, 20 nm or more. In addition, the ratio of the depth to the width of the recess 95, that is, the depth-to-width ratio (i.e., the value obtained by dividing the depth of the recess 95 by the width), is, for example, 5 or more.

[0086] Furthermore, the recess 95 can also be a recess other than a groove, such as a roughly circular hole when viewed from above. When the recess 95 is a hole, the width of the recess 95 is the diameter of the hole when viewed from above.

[0087] exist Figure 4The image shows a substrate 9 before etching by the substrate processing apparatus 1. In the substrate 9 before etching, the interior of the recess 95 and the end faces 941 of the two microstructures 94 are covered by a film 96 to be processed. The film 96 is, for example, a conductive film formed of a conductor. The film 96 is, for example, a metal film containing one or more metals selected from titanium (Ti), tantalum (Ta), tungsten (W), copper (Cu), and aluminum (Al). The film 96 contains, for example, at least one of TiN (titanium nitride), TaN (tantalum nitride), TiAl (titanium aluminum), and TiAlC (titanium aluminum carbide). Furthermore, the film 96 may also be formed from a material other than the aforementioned materials (e.g., MnO). The thickness of the film 96 on the end faces 941 of the microstructures 94 (i.e., the thickness of the film 96) is... Figure 4 The thickness in the left and right directions is, for example, more than 1 nm and less than 5 nm.

[0088] Next, refer to Figures 5 to 11 The processing flow of substrate 9 in substrate processing apparatus 1 is described. Figure 5 This is a diagram showing the processing flow of substrate 9. Figure 6 , Figure 7 and Figure 11 This is a diagram showing the substrate processing apparatus 1 during the processing of substrate 9. Figure 8A and Figure 8B This is a diagram showing an example of a waveform representing an applied voltage. Figures 9A to 9D ,and Figures 10A to 10D It is a cross-sectional view showing a portion of the substrate 9 magnified.

[0089] In the processing of substrate 9 in substrate processing apparatus 1, generally speaking, the substrate 9 is subjected to overall etching using top plate 31 and partition plate nozzle 51, and local etching using movable nozzle 52. After the overall etching and local etching are completed, substrate 9 is rinsed and then dried.

[0090] When processing substrate 9, firstly, as... Figure 2 As shown, the substrate 9 is moved into the substrate processing apparatus 1 and held in a generally horizontal position by the substrate holding part 21 (step S11). Thus, the first electrode 61 provided on each clamping pin 212 is in direct contact with the substrate 9 and electrically connected. During the movement of the substrate 9 in step S11, the top plate 31 is located at a position significantly separated from the substrate holding part 21 above it. Furthermore, the movable nozzle 52 is located in the retracted position.

[0091] After the substrate 9 is held by the substrate holding part 21, the top plate 31 is lowered by the top plate moving mechanism 33, and as... Figure 6 As shown, the designated position is located above the substrate 9 (hereinafter also referred to as the "ejection position"). Additionally, the movable nozzle 52 (see reference) Figure 2It remains in the retreat position.

[0092] Next, the substrate rotation mechanism 23 is driven by the motion control unit 82 of the control unit 8, thereby initiating the rotation of the substrate 9. Additionally, the processing liquid supply unit 5 is controlled by the motion control unit 82, thereby continuously supplying the etching processing liquid from the partition plate nozzle 51 to the center of the upper surface 91 of the substrate 9. This processing liquid utilizes the centrifugal force generated by the rotation of the substrate 9 to diffuse across the entire upper surface 91 of the substrate 9, and interacts with the film 96 to be processed on the substrate 9 (see reference). Figure 4 Contact (step S12). In step S12, the substrate 9 rotates at a relatively low speed, and the almost entire upper surface 91 of the substrate 9 is covered with the etching solution. That is, in step S12, a so-called liquid coating process is performed across the almost entire upper surface 91 of the substrate 9. In addition, a portion of the processing solution supplied to the substrate 9 is dispersed radially outward from the periphery of the substrate 9 by the centrifugal force generated by the rotation of the substrate 9 and is received by the cup portion 4. The rotational speed of the substrate 9 in step S12 is, for example, 15 rpm or less.

[0093] In this embodiment, the film 96 to be treated is a conductive film formed of titanium nitride (TiN), and the sidewall surface 942 of the microstructure 94 (refer to...) Figure 4 The material is hafnium oxide (HfO2). The treatment solution is a conductive liquid formed by adding an electrolyte to hydrogen peroxide water, which is used as an etching solution. The resistivity of this treatment solution is, for example, 0.1. The preferred value is 0.05. The electrolyte can be, for example, an aqueous solution of hydrochloric acid (HCl), sulfuric acid (H₂SO₄), or ammonia. Furthermore, the resistivity of the treatment solution can be greater than 0.1. Alternatively, the treatment solution can be pure hydrogen peroxide water without the addition of hydrochloric acid or the like. It can also be a mixture of hydrogen peroxide water and hydrochloric acid aqueous solution, i.e., SC2.

[0094] After the entire upper surface 91 of the substrate 9 has been covered with the etching solution, the top plate 31 is lowered by the top plate moving mechanism 33, and as... Figure 7 As shown, it is located in the vertical direction relative to the ejection position (reference). Figure 6 (The location is closer to substrate 9.) In the following description, Figure 7 The position of the top plate 31 shown is also called the "etching position".

[0095] With the top plate 31 in the etching position, the lower surface 311 of the top plate 31 is slightly separated from the upper surface 91 of the substrate 9 by upwards. The vertical distance between the lower surface 311 of the top plate 31 and the upper surface 91 of the substrate 9 is, for example, about 4 mm. The gap between the lower surface 311 of the top plate 31 and the upper surface 91 of the substrate 9 is almost entirely filled with the processing liquid, thereby forming a liquid film 50 of the processing liquid. The second electrode 62, provided on the lower surface 311 of the top plate 31, is electrically connected to the etching processing liquid that forms the liquid film 50 by directly contacting the upper surface of the liquid film 50 (step S13).

[0096] As described above, the liquid film 50 is formed across substantially the entire upper surface 91 of the substrate 9. For example, the liquid film 50 is in direct contact with the first electrodes 61 disposed on each clamping pin 212 at the periphery of the substrate 9. In other words, the plurality of first electrodes 61 are in direct contact with the periphery of the liquid film 50. Alternatively, each first electrode 61 may not be in direct contact with the liquid film 50.

[0097] Furthermore, with the top plate 31 in the etching position, the action of spraying the processing liquid from the partition plate nozzle 51 can continue or stop. Similarly, the rotation of the substrate 9 can also continue or stop. With the top plate 31 in the etching position, the top plate 31 can be rotated by the top plate rotation mechanism 32, or it can remain stationary without rotating. When the top plate 31 is rotated, its rotational speed and direction are, for example, the same as those of the substrate 9. If the top plate 31 is not rotated, the top plate rotation mechanism 32 can be omitted.

[0098] Next, the power control unit 81 of the control unit 8 controls the power supply unit 66 to apply a voltage between the first electrode 61 and the second electrode 62. Thus, the voltage is applied through the processing liquid on the substrate 9 to the substrate 9, which is electrically connected to the first electrode 61, and the second electrode 62. In other words, the substrate 9 and the second electrode 62 are a pair of electrodes separated by the processing liquid, and a voltage is applied between these two electrodes.

[0099] The applied voltage between the first electrode 61 and the second electrode 62 is controlled by the power supply control unit 81, and is repeatedly switched between different first and second voltages at a predetermined switching cycle. Thus, the sidewall surface 942 of the microstructure 94 (refer to...) Figure 4 The potential of the device is repeatedly switched between the first potential and the second potential according to the switching cycle (step S14).

[0100] The power supply unit 66 applies a voltage to the first electrode 61 based on the potential of the second electrode 62. Both the first and second potentials are based on the second electrode 62. The first potential is 0 V or higher. The second potential is 0 V or lower than the first potential. Therefore, when the first potential is 0 V, the second potential is less than 0 V. The first potential is, for example, +8 V or lower. The second potential is, for example, -8 V or higher. The upper limit of the first potential and the lower limit of the second potential can be varied.

[0101] The switching period is preferably 0.05 seconds or more. The switching period is preferably 20 seconds or less. When the applied voltage is a DC voltage, the switching period is preferably 0.5 seconds or more, more preferably 1 second or more, and even more preferably 2 seconds or more. Furthermore, when the applied voltage is a DC voltage, the switching period is preferably 18 seconds or less, more preferably 12 seconds or less, and even more preferably 6 seconds or less.

[0102] When the applied voltage is AC, a switching period of 0.05 seconds or more corresponds to a frequency of 20 Hz or less, and a switching period of 20 seconds or less corresponds to a frequency of 0.05 Hz or more. When the applied voltage is AC, the switching period is preferably 0.1 seconds or more (i.e., a frequency of 10 Hz or less), more preferably 0.2 seconds or more (i.e., a frequency of 5 Hz or less). When the applied voltage is AC, the switching period is preferably 2 seconds or less (i.e., a frequency of 0.5 Hz or more), more preferably 1 second or less (i.e., a frequency of 1 Hz or more).

[0103] The switching of the applied voltage in step S14 (i.e., the switching of the potential of the sidewall surface 942) is between the liquid film 50 of the processing liquid and the film 96 to be processed on the substrate 9 (refer to...). Figure 4 In the contact state, the process continues for a specified time. This etches (so-called electrolytic etching) onto approximately the entire upper surface 91 of the substrate 9, removing the film 96 to be processed from the upper surface 91 of the substrate 9. In the following description, the etching performed on approximately the entire upper surface 91 of the substrate 9 using the second electrode 62 is also referred to as "overall etching".

[0104] Figure 8A and Figure 8B This is a diagram showing an example of the waveform of the applied voltage applied from the power supply unit 66 in step S14. Figure 8A This is an example of a waveform when a DC voltage is applied. Figure 8B This is an example of a waveform when an AC voltage is applied. Figure 8A and Figure 8BThe horizontal axis represents elapsed time, and the vertical axis represents the applied voltage between the first electrode 61 and the second electrode 62. In this specification, the applied voltage is set to positive when the potential of the first electrode 61 is higher than the potential of the second electrode 62, and the applied voltage is set to negative when the potential of the first electrode 61 is lower than the potential of the second electrode 62. In the following description, when the applied voltage is positive, it will be stated as "a positive voltage is applied to the first electrode 61", and when the applied voltage is negative, it will be stated as "a negative voltage is applied to the first electrode 61".

[0105] Figure 8A In the example shown, the applied voltage waveform is a rectangular wave. The maximum applied voltage (i.e., the first voltage) is +8 V, and the minimum applied voltage (i.e., the second voltage) is -8 V. As described above, the voltage is applied at a specified switching period T. D The voltage repeatedly switches between the first voltage and the second voltage. In the following description, during each switching cycle T of the applied voltage... D The time during which a positive voltage is applied is also called the "first application time T". Dp The time during which a negative voltage is applied is also called the "second application time T". Dm ". Figure 8A In the example shown, the first application time T Dp With the second application time T Dm Same, T D / 2. Furthermore, the first and second voltages can be appropriately varied, and their absolute values ​​do not need to be the same. Additionally, the first application time T... Dp With the second application time T Dm They don't have to be the same; they can also be different.

[0106] Figure 8B This is an example of a waveform when an AC voltage is applied. Figure 8B In the example shown, the waveform of the AC voltage is a sine wave. Figure 8B The vertical axis represents the instantaneous value of the applied voltage. The maximum applied voltage (i.e., the first voltage) is +8 V, and the minimum applied voltage (i.e., the second voltage) is -8 V. As described above, the voltage is applied at a specified switching period T. A The voltage repeatedly switches between the first voltage and the second voltage. In the following description, during each switching cycle T of the applied voltage... A The time during which a positive voltage is applied is also called the "first application time T". Ap The time during which a negative voltage is applied is also called the "second application time T". Am ". Figure 8B In the example shown, the first application time T Ap With the second application time T Am Same, T A / 2. Furthermore, the first and second voltages can be appropriately varied, and their absolute values ​​do not need to be the same. Additionally, the first application time T... Ap With the second application time T Am They don't necessarily have to be the same; they can also be different. When the applied voltage is an alternating current voltage, the waveform of the applied voltage is not limited to a sine wave; for example, it can also be a triangular wave or a sawtooth wave.

[0107] In step S14, the power supply unit 66 is controlled by the power supply control unit 81, causing the applied voltage to repeatedly switch between a first voltage and a second voltage. This promotes etching of the film 96 to be processed, thereby increasing the etching rate. In particular, it promotes etching of the film 96 to be processed within the recess 95, thereby increasing the etching rate.

[0108] The principle behind increasing the etching rate of the film 96 within the recess 95 by repeatedly switching the applied voltage is not rigorously defined. Several alternative principles considered as such are explained below.

[0109] First, refer to and Figure 4 Roughly the same sectional view, i.e. Figures 9A to 9D The first principle will be explained. Figures 9A to 9D The situation shown is that, Figure 4 The etching of the treated film 96 shown progresses to some extent; the treated film 96 on the end face 941 of the microstructure 94 is removed, and the treated film 96 inside the recess 95 is also slightly removed. Additionally, in Figures 9A to 9D In the diagram, for simplicity, the surface of the treated film 96 (i.e., the end face opposite to the bottom of the recess 95, i.e., the face on the left side of the diagram) is schematically drawn as being perpendicular to the left-right direction. The following... Figures 10A to 10D The same applies to China. Furthermore, Figures 9A to 9D In the example shown, the etching solution contains hydrogen peroxide as an etchant.

[0110] exist Figure 9A In the diagram, the first electrode 61 (reference) is shown. Figure 2 A positive voltage is applied. By applying a positive voltage to the first electrode 61, the surface of the film 96 to be treated within the recess 95 becomes positively charged. Additionally, the sidewall surfaces 942 (i.e., the inner surfaces of the recess 95) and end faces 941 of the two microstructures 94 located on either side of the recess 95 also become positively charged. Therefore, hydrogen peroxide molecules 71 and water molecules 72, which are polar molecules (also called polarized molecules), are adsorbed onto the surface of the film 96 to be treated, and onto the surface of the microstructures 94 (i.e., the sidewall surfaces 942 and end faces 941). Specifically, the negatively charged portions of the hydrogen peroxide molecules 71 and the negatively charged portions of the water molecules 72 are adsorbed onto the surfaces of the film 96 to be treated and the microstructures 94.

[0111] exist Figure 9A In the diagram, hydrogen peroxide molecules 71 are schematically represented by circles, and arrows inside these circles indicate the charge concentration of hydrogen peroxide molecules 71. Specifically, the head (i.e., the arrowhead) of the arrow indicates the location of positive charge concentration in hydrogen peroxide molecules 71, and the end of the arrow opposite to the head indicates the location of negative charge concentration. Water molecules 72 are treated in a similar manner. Furthermore, the circle schematically representing water molecules 72 is drawn smaller than the circle schematically representing hydrogen peroxide molecules 71. Figure 9B and Figure 9D The same applies to China.

[0112] When a positive voltage is applied to the first electrode 61, the treated film 96 is etched by hydrogen peroxide molecules 71 adsorbed on the surface of the treated film 96. Furthermore, the hydrogen peroxide molecules 71 used to etch the treated film 96 are converted into hydroxide ions (OH-). - Hydrogen peroxide molecules 71 disappear from the surface of the treated film 96 as etching of the treated film 96 progresses. Consequently, hydrogen peroxide molecules 71 decrease or disappear on the surface of the treated film 96 and in the area near the treated film 96 (i.e., the inner surface of the recess 95) of the microstructure 94. Figure 9B As shown, the surface of the treated film 96 and the inner side of the recess 95 are covered with water molecules 72. As a result, the adsorption of hydrogen peroxide molecules 71 onto the surface of the treated film 96 is hindered, the etching rate of the treated film 96 decreases, or the etching of the treated film 96 stops.

[0113] Therefore, in the substrate processing apparatus 1, by switching the positive and negative values ​​of the voltage applied to the first electrode 61 at predetermined times, a negative voltage is applied to the first electrode 61, and so on. Figure 9C As shown, the surfaces of the treated membrane 96 and the microstructure 94 are negatively charged. Consequently, water molecules 72 adsorbed on the surfaces of the treated membrane 96 and the microstructure 94 (e.g., the inner surface of the recess 95) are electrolyzed into hydrogen molecules and hydroxide ions, and removed from the surfaces of the treated membrane 96 and the microstructure 94. As a result, a state is achieved where hydrogen peroxide molecules 71 can be adsorbed onto the surface of the treated membrane 96.

[0114] In the substrate processing apparatus 1, a positive voltage is applied to the first electrode 61 by switching the positive and negative values ​​of the voltage applied to the first electrode 61 at predetermined times, and so on. Figure 9D As shown, the surfaces of the treated film 96 and the microstructure 94 (e.g., the inner surface of the recess 95) are positively charged. Hydrogen peroxide molecules 71 are thus adsorbed onto the surface of the treated film 96, and etching of the treated film 96 is achieved through these hydrogen peroxide molecules 71. As a result, etching of the treated film 96 within the recess 95 is promoted, increasing the etching rate.

[0115] Secondly, refer to Figures 10A to 10D The second principle will be explained. Figure 10A In the diagram, the first electrode 61 (reference) is shown. Figure 2 A positive voltage is applied. By applying a positive voltage to the first electrode 61, the sidewall surfaces 942 (i.e., the inner surfaces of the recess 95) of the two microstructures 94 located on both sides of the recess 95 become positively charged. In other words, the potential of the sidewall surfaces 942 of the microstructures 94 becomes higher than the potential of the processing liquid. Therefore, the etchant, i.e., the negative ions 73, present around the recess 95, easily enters the recess 95. As a result, the contact between the surface of the treated film 96 and the negative ions 73, which act as the etchant, increases, and the etching of the treated film 96 is promoted.

[0116] As the etching of the treated film 96 progresses, such as Figure 10B As shown, the negatively charged product 74 generated by etching increases and remains within the recess 95, making it difficult for the negative ions 73, acting as the etchant, to penetrate the recess 95. Consequently, the contact between the negative ions 73 and the treated film 96 decreases, the etching rate of the treated film 96 decreases, or the etching of the treated film 96 stops. Furthermore, in Figure 10B In order to make the diagram easier to understand, product 74 is marked with parallel diagonal lines ( Figure 10C The same applies to China.

[0117] Therefore, the positive and negative values ​​of the voltage applied to the first electrode 61 are switched at a predetermined time to apply a negative voltage to the first electrode 61. Thus, as... Figure 10C As shown, the sidewall surfaces 942 of the two microstructures 94 located on both sides of the recess 95 (i.e., the inner surfaces of the recess 95) are negatively charged. In other words, the potential of the sidewall surfaces 942 of the microstructures 94 becomes lower than the potential of the processing liquid. As a result, positive ions 75 present around the recess 95 enter the recess 95, and the products 74 retained in the recess 95 are discharged to the outside of the recess 95.

[0118] Then, the polarity of the voltage applied to the first electrode 61 is switched at a predetermined time to apply a positive voltage to the first electrode 61. Thus, as... Figure 10D As shown, the sidewall surface 942 of the microstructure 94 (i.e., the inner surface of the recess 95) is positively charged. As a result, the etchant present around the recess 95, i.e., negative ions 73, enters the recess 95, contacts the film 96 being treated, and promotes the etching of the film 96 being treated, thereby increasing the etching rate.

[0119] Next, the third principle will be explained. During the etching of the film 96 being processed, positive and negative voltages are alternately applied to the first electrode 61. It was then confirmed that when one voltage (positive or negative) is applied, bubbles are generated within the recess 95, while when the other voltage is applied, no bubbles are generated. Therefore, if only this single voltage is continuously applied to the first electrode 61, bubbles will increase and become trapped within the recess 95, reducing the etching rate of the film 96, or even stopping the etching process. Therefore, by switching the positive and negative voltages applied to the first electrode 61 at predetermined times, these bubbles are expelled from the recess 95. This suppresses the bubbles from hindering etching, thereby increasing the etching rate.

[0120] Next, the fourth principle will be explained. The following explanation assumes that the film being treated 96 is a TiN film, and the etching solution is a liquid formed by adding hydrochloric acid to an aqueous hydrogen peroxide solution as an electrolyte. If a positive voltage is applied to the first electrode 61, then the ligands in the etching solution, namely chloride ions (Cl... - The ligands easily enter the recess 95. This promotes the etching of the treated film 96, increasing the etching rate. As etching progresses, the complex (Ti-Cl) generated by etching increases and remains within the recess 95, making it difficult for ligands to enter the recess 95. As a result, the etching rate of the treated film 96 decreases, or the etching of the treated film 96 stops.

[0121] Therefore, by switching the voltage applied to the first electrode 61 from positive to negative at predetermined times, a negative voltage is applied to the first electrode 61, thereby discharging the complex out of the recess 95. Then, by applying a positive voltage to the first electrode 61, as described above, the ligands in the processing solution are made to easily enter the recess 95. This promotes the etching of the treated film 96, increasing the etching rate.

[0122] Furthermore, it is not clearly stated which of the first to fourth principles is dominant. Additionally, the increase in etching rate may be due to a combination of these principles with other principles, or it may be due to principles other than these. In either case, in step S14, the applied voltage is repeatedly switched at a switching cycle of 0.05 seconds or more, causing the potential of the sidewall surface 942 of the microstructure 94 to repeatedly switch between the first potential and the second potential, thereby promoting the etching of the film 96 to be processed within the recess 95.

[0123] exist Figure 7In the substrate processing apparatus 1 shown, after a predetermined processing time has elapsed since step S14, the supply of processing liquid from the partition plate nozzle 51 to the substrate 9 and the application of voltage via the power supply unit 66 are stopped, thus completing the overall etching of the substrate 9. In step S14, etching is performed simultaneously on approximately the entire upper surface 91 of the substrate 9, thereby shortening the time required to etch the substrate 9. Furthermore, as described above, etching can be performed across approximately the entire upper surface 91 of the substrate 9, increasing the etching rate of the film 96 being processed.

[0124] On the other hand, in step S14, the substrate 9 rotates at a low speed, and the processing liquid does not move much on the substrate 9. Therefore, it is possible for the etching rate to differ due to the radial position on the substrate 9.

[0125] For example, the central portion of the upper surface 91 of the substrate 9 faces the nozzle outlet of the partition plate nozzle 51 in the vertical direction, but does not face the second electrode 62 in the vertical direction. In other words, the second electrode 62 is not vertically above the central portion of the upper surface 91 of the substrate 9. As a result, the etching rate may be lower in the central portion of the upper surface 91 of the substrate 9 compared to the area outside the central portion. In addition, for example, the temperature of the liquid film 50 of the processing liquid is lower in the peripheral portion of the upper surface 91 of the substrate 9 compared to the area outside the peripheral portion, which may also reduce the etching rate.

[0126] In the following description, during the overall etching in step S14, the region on the upper surface 91 of the substrate 9 with a lower etching rate than other regions (i.e., less etching in step S14 than other regions) is also referred to as a "low etching rate region". The low etching rate region has been known in advance by the operator of the substrate processing apparatus 1, and the substrate processing apparatus 1 is controlled by the control unit 8 based on the location of the low etching rate region.

[0127] After the overall etching in step S14 is completed, the top plate 31 rises from the etching position via the top plate moving mechanism 33, separating itself from the liquid film 50 upwards, and is located at... Figure 11 The position shown is (hereinafter also referred to as the "retreat position"). When the top plate 31 is in the retreat position, the nozzle moving mechanism 55 is controlled by the action control unit 82 to move the movable nozzle 52 horizontally above the substrate 9 from the retreat position. The movable nozzle 52 is located between the substrate 9 and the top plate 31, above the low etch rate region. Figure 11 In the example shown, the central portion of the upper surface 91 of the substrate 9 is a low etching rate region, and the movable nozzle 52 is located above this central portion of the substrate 9.

[0128] Then, the operation control unit 82 of the control unit 8 controls the processing liquid supply unit 5, thereby continuously supplying the processing liquid for etching from the movable nozzle 52 to the center of the upper surface 91 of the substrate 9. This processing liquid interacts with the film 96 to be processed on the substrate 9 (see reference). Figure 4 (Step S15) Contact. Furthermore, the substrate rotation mechanism 23 is controlled by the motion control unit 82, thereby increasing the rotational speed of the substrate 9. The rotational speed of the substrate 9 is, for example, 10 rpm or more, preferably 10 rpm to 1500 rpm. The processing liquid supplied to the substrate 9 from the movable nozzle 52 diffuses radially outward using the centrifugal force generated by the rotation of the substrate 9, scattering radially outward from the periphery of the substrate 9 and being received by the cup portion 4. In step S15, the processing liquid ejected from the movable nozzle 52 covers the entire low-etch rate region on the substrate 9. On the other hand, areas outside the low-etch rate region of the upper surface 91 of the substrate 9 may also be exposed from the processing liquid.

[0129] Next, the power supply unit 66 is controlled by the power supply control unit 81 of the control unit 8 to apply a voltage between the first electrode 61 and the third electrode 63. This applies a voltage between the substrate 9 and the processing liquid on the substrate 9. The applied voltage between the substrate 9 and the processing liquid is applied in approximately the same manner as in step S14, and is repeatedly switched between different first and second voltages at a predetermined switching cycle under the control of the power supply control unit 81. This causes the sidewall surface 942 of the microstructure 94 (refer to…) to… Figure 4 The potential of the device is repeatedly switched between the first potential and the second potential according to the switching cycle (step S16).

[0130] The preferred range and waveform of the applied voltage, as well as the preferred range of the switching period of the applied voltage in step S16, are substantially the same as in step S14. Furthermore, the first and second voltages in step S14 may be the same as or different from the first and second voltages in step S16. Additionally, the switching period and waveform of the applied voltage in step S14 may be the same as or different from those in step S16.

[0131] The switching of the applied voltage in step S16 (i.e., the switching of the potential of the sidewall surface 942) is performed on the treated film 96 on the substrate 9 (refer to...) Figure 4 In the contact state, the process continues for a specified time. This etches the low-etch-rate region on the upper surface 91 of the substrate 9 (so-called electrolytic etching), removing the treated film 96 from the upper surface 91 of the substrate 9. In the following description, the etching performed on the upper surface 91 of the substrate 9 using the third electrode 63 is also referred to as "local etching".

[0132] Regarding the case where the low etching rate region is relatively large during the local etching in steps S15-S16, the nozzle movement mechanism 55 can be controlled by the motion control unit 82, thereby causing the movable nozzle 52, which is spraying the processing liquid, to swing approximately horizontally above the low etching rate region. Specifically, for example, the movable nozzle 52 repeatedly moves back and forth between two points overlapping the horizontal movement path of the movable nozzle 52 when viewed from above the periphery of the low etching rate region. The swing period of the movable nozzle 52 (i.e., the time required for one back-and-forth movement in this back-and-forth movement) is, for example, 15 seconds to 2700 seconds. This swing period is longer than the switching period of the applied voltage. This swing period is, for example, 300 to 600 times the switching period. Furthermore, if the low etching rate region is relatively small, the movable nozzle 52 may not swing.

[0133] The actions of supplying processing liquid from the movable nozzle 52 in step S15 and switching the applied voltage in step S16 are performed continuously for a predetermined time while the substrate 9 is rotating. This etches the low-etch-rate region (so-called electrolytic etching), thereby increasing the amount of etching in the low-etch-rate region. As a result, the uniformity of etching across the entire upper surface 91 of the substrate 9 is improved.

[0134] In addition, Figure 11 In the previous description, the case where the central portion of the upper surface 91 of the substrate 9 is a low etch rate region was explained. However, as mentioned above, the low etch rate region could also be the peripheral portion of the upper surface 91 of the substrate 9. Furthermore, the low etch rate region could be both the central portion and the peripheral portion of the upper surface 91 of the substrate 9. The low etch rate region could also be a region other than the central portion and the peripheral portion of the upper surface 91 of the substrate 9. In any case, steps S15 to S16 are performed with the movable nozzle 52 positioned above the low etch rate region, thereby increasing the etching amount in the low etch rate region.

[0135] exist Figure 11 In the substrate processing apparatus 1 shown, after a predetermined processing time has elapsed since step S16, the supply of processing liquid from the movable nozzle 52 to the substrate 9 and the application of voltage via the power supply unit 66 are stopped, thereby halting the local etching of low-etching-rate regions on the substrate 9. After the local etching is completed, rinsing liquid is supplied from the movable nozzle 52 to the upper surface 91 of the substrate 9, and the rotational speed of the substrate 9 is increased.

[0136] The rinsing solution supplied to the substrate 9 diffuses across the entire upper surface 91 of the substrate 9 using the centrifugal force generated by the rotation of the substrate 9. This performs a rinsing process, i.e., washing away the processing solution and the like adhering to the substrate 9 (step S17). The rotational speed of the substrate 9 in step S17 is, for example, 800 rpm or more. The rinsing solution on the substrate 9 is dispersed radially outward from the periphery of the substrate 9 using the centrifugal force generated by the rotation of the substrate 9 and is received by the cup portion 4.

[0137] After rinsing the substrate 9 for a predetermined time, the supply of rinsing solution is stopped. Then, the rotational speed of the substrate 9 is further increased. The rinsing solution on the substrate 9 is then removed, thereby performing a drying process on the substrate 9 (step S18). The rotational speed of the substrate 9 in step S18 is, for example, 1000 rpm or more. Furthermore, the drying process can be performed using various known methods. After the drying process of the substrate 9 is completed, the rotation of the substrate 9 is stopped, and the substrate 9 is removed from the substrate processing apparatus 1.

[0138] Furthermore, in the substrate processing apparatus 1, it is not necessary to perform local etching after overall etching; the overall etching in steps S13 to S14 can be performed after the local etching in steps S15 to S16.

[0139] Furthermore, in the substrate processing apparatus 1, local etching is not necessarily performed on areas with low etching rates; it can also be performed on areas that the operators of the substrate processing apparatus 1 or others deem necessary to be locally etched. In this case, the movable nozzle 52 is positioned above the rotating substrate 9 at a desired radial position and locally etches a portion of the upper surface 91 of the substrate 9 corresponding to that desired position.

[0140] In the substrate processing apparatus 1, it is not necessary to switch the applied voltage in both the overall etching and the local etching processes. For example, the voltage switching may only be performed in one of the overall etching and the local etching processes. Specifically, in the overall etching process of steps S13 to S14, the applied voltage may be switched as described above, while in the local etching process of steps S15 to S16, the applied voltage may not be switched, and a fixed applied voltage may always be applied between the first electrode 61 and the third electrode 63. Alternatively, in the overall etching process of steps S13 to S14, the applied voltage may not be switched, and a fixed applied voltage may always be applied between the first electrode 61 and the second electrode 62, while in the local etching process of steps S15 to S16, the applied voltage may be switched as described above. Furthermore, it is also possible that the applied voltage may not be switched in either the overall etching or the local etching process, and a fixed applied voltage may always be applied.

[0141] Next, referring to Tables 1 to 7, Examples 1 to 28 and Comparative Examples 1 to 3 of etching the treated film 96 in the recess 95 will be described.

[0142] [Table 1]

[0143]

[0144] [Table 2]

[0145]

[0146] [Table 3]

[0147]

[0148] [Table 4]

[0149]

[0150] [Table 5]

[0151]

[0152] [Table 6]

[0153]

[0154] [Table 7]

[0155]

[0156] In Examples 1-28 and Comparative Example 2, the etching of the film 96 to be processed in the substrate processing apparatus 1 was simulated, and the etching was performed using… Figure 12 The experimental apparatus 97 shown was used to perform the treatments corresponding to steps S11 to S18 on the test piece 98. In Comparative Examples 1 and 3, the experimental apparatus 97 was used to perform the treatments corresponding to steps S11 to S13, S15, and S17 to S18 on the test piece 98. That is, in Comparative Examples 1 and 3, the voltage application in steps S14 and S16 was omitted. Furthermore, these treatments performed on the test piece 98 were carried out in an atmospheric environment at room temperature (e.g., 25°C).

[0157] The experimental apparatus 97 includes an electrolytic cell 971, a test electrode 972, a counter electrode 973, a reference electrode 974, and a power supply unit 975. An "VM-3" manufactured by EC FRONTIER Inc. is used as the electrolytic cell 971. The test piece 98 is placed on the base 976 of the electrolytic cell 971, and the tank cover 977 on the base 976 is filled with a processing solution for etching. The upper surface of the test piece 98 is in contact with the processing solution inside the tank cover 977. The contact area between the test piece 98 and the processing solution is defined as 1 cm² by an O-ring. 2On the upper surface of the test piece 98, a plurality of recesses 95 are formed (see reference). Figure 4 ) multiple microstructures 94.

[0158] Use alligator clips as a reference to the first electrode 61 (see). Figure 2 The corresponding test electrode 972 is used. The test electrode 972 is electrically connected to the test piece 98 by clamping the end of the test piece 98 with the alligator clip. The "CE-100" manufactured by EC FRONTIER Inc. is used as the relative electrode 973. The "RE-T16" manufactured by EC FRONTIER Inc. is used as the reference electrode 974. The "RE-T16" is a silver-silver chloride electrode (Ag / AgCl electrode) using a 3.0 mol / L potassium chloride (KCl) aqueous solution as the internal solution, and its potential relative to the NHE (standard hydrogen electrode) is +0.208 V at 25°C. The relative electrode 973 and the reference electrode 974 are inserted into the tank cover 977 from the top, and come into contact with the processing solution inside the tank cover 977. A potentiostat "VSP-300-SC" manufactured by Bio-Logic Science Inc. is used as the power supply unit 975.

[0159] In Examples 1-17 and Comparative Examples 1-2 shown in Tables 1-4, the etching solution used was SC2, and the etching time (i.e., the total processing time of steps S14 and S16) was 60 minutes. The etching solution was a mixture of approximately 20 mol% hydrogen peroxide water, approximately 22 mol% hydrochloric acid aqueous solution, and DIW mixed in a volume ratio of 1:1:8.

[0160] In Examples 18-28 and Comparative Example 3 shown in Tables 5-7, the etching solution used was hydrogen peroxide water, and the etching time (i.e., the total processing time of steps S14 and S16) was 120 minutes. The etching solution was a mixture of approximately 20 mol% hydrogen peroxide water and DIW at a volume ratio of 1:8. No other chemical solutions such as hydrochloric acid were added to the etching solution. That is, the concentration of hydrochloric acid in the etching solution was 0 mol% and 0% by mass.

[0161] The etching amounts in Tables 1 through 7 are... Figure 13 The surface 961 of the film 96 being processed, indicated by a double-dotted line, is in the state before etching begins. Figure 13 The depth direction of the recess 95 between the surfaces 962 of the treated film 96 after etching at the specified time (represented by solid lines) is shown in the image. Figure 13 The distance D1 in the left and right directions (within the range). Furthermore, as... Figure 13As shown, distance D1 is the distance between the surface 961 of the film being processed 96 and the lowest point of the surface 962 of the film being processed 96 within the recess 95 (i.e., the position furthest from surface 961 in the depth direction). This etching amount is the arithmetic mean of the distances D1 of the six recesses 95. This distance D1 is obtained by observing a cross-sectional SEM image of the substrate 9.

[0162] As described above, in Examples 1-17 and Comparative Examples 1-2 shown in Tables 1-4, SC2 was used as the processing solution. In Examples 1-5 shown in Table 1, the first and second voltages of the applied voltage in steps S14 and S16 were changed, and the etching amount of the treated film 96 was measured. In Example 1, the applied voltage from the power supply unit 975 was a DC voltage, the second voltage was set to -8 V, and the first voltage was set to +8 V. In addition, the switching cycle of the applied voltage was 6 seconds. That is, in Example 1, the potential of the sidewall surface 942 of the microstructure 94 (i.e., the inner surface of the recess 95) switched between -8 V, which is the second potential, and +8 V, which is the first potential, with a switching cycle of 6 seconds. In Example 1, the etching amount was 24 nm.

[0163] Example 2 is identical to Example 1 except that the second voltage is set to -1 V and the first voltage is set to +1 V. In Example 2, the potential of the sidewall surface 942 of the microstructure 94 switches between -1 V (the second potential) and +1 V (the first potential) with a switching cycle of 6 seconds. In Example 2, the etching depth is 26 nm.

[0164] Example 3 is identical to Example 1 except that the second voltage is set to -0.8 V and the first voltage is set to +0.8 V. In Example 3, the potential of the sidewall surface 942 of the microstructure 94 switches between -0.8 V (the second potential) and +0.8 V (the first potential) at a switching cycle of 6 seconds. In Example 3, the etching depth is 25.5 nm.

[0165] Example 4 is identical to Example 1 except that the second voltage is set to -0.6 V and the first voltage is set to +0.6 V. In Example 4, the potential of the sidewall surface 942 of the microstructure 94 switches between -0.6 V (the second potential) and +0.6 V (the first potential) at a switching cycle of 6 seconds. In Example 4, the etching depth is 25.5 nm.

[0166] Example 5 is identical to Example 1 except that the second voltage is set to -0.5 V and the first voltage is set to +0.5 V. In Example 5, the potential of the sidewall surface 942 of the microstructure 94 switches between -0.5 V (the second potential) and +0.5 V (the first potential) at a switching cycle of 6 seconds. In Example 5, the etching depth is 27.5 nm.

[0167] In Comparative Example 1, as described above, the voltage application in steps S14 and S16 was omitted. In Comparative Example 1, the etching depth was 11 nm.

[0168] Comparing Examples 1-5 with Comparative Example 1, it can be seen that by performing steps S14 and S16 (switching the applied voltage), the etching rate of the film 96 in the recess 95 will increase even when the applied voltage is different.

[0169] In Examples 6-10 and Comparative Example 2 shown in Table 2, the first and second applied voltages in steps S14 and S16 were changed, and the etching amount of the treated film 96 was measured. In Example 6, the applied voltage from the power supply unit 975 was a DC voltage, the second voltage was set to -8 V, and the first voltage was set to 0 V. Furthermore, the switching cycle of the applied voltage was 6 seconds. That is, in Example 6, the potential of the sidewall surface 942 of the microstructure 94 (i.e., the inner surface of the recess 95) switched between -8 V (the second potential) and 0 V (the first potential) with a switching cycle of 6 seconds. In Example 6, the etching amount was 26 nm.

[0170] Example 7 is identical to Example 6 except that the first voltage is set to +1 V. In Example 7, the potential of the sidewall surface 942 of the microstructure 94 switches between -8 V (the second potential) and +1 V (the first potential) at a switching cycle of 6 seconds. In Example 7, the etching depth is 25.5 nm.

[0171] Example 8 is identical to Example 6 except that the power supply unit 975 is turned off at a predetermined time after the first voltage is applied. With the power supply unit 975 turned off, the open-circuit potential of the surface of the test piece 98 is +0.6 V to +0.8 V. In Example 8, the potential of the sidewall surface 942 of the microstructure 94 switches between -8 V (the second potential) and the open-circuit potential (the first potential) at a switching cycle of 6 seconds. In Example 8, the etching depth is 25.5 nm.

[0172] Example 9 is identical to Example 6 except that the first voltage is set to +8 V. In Example 9, the potential of the sidewall surface 942 of the microstructure 94 switches between -8 V (the second potential) and +8 V (the first potential) at a switching cycle of 6 seconds. In Example 9, the etching depth is 27 nm.

[0173] Example 10 is identical to Example 7 except that the second potential is set to -1 V. In Example 10, the potential of the sidewall surface 942 of the microstructure 94 switches between -1 V (the second potential) and +1 V (the first potential) at a switching cycle of 6 seconds. In Example 10, the etching depth is 25.5 nm.

[0174] Furthermore, in Examples 9 and 10, the experimental conditions were the same as in Examples 1 and 2 of Table 1, but the experimental dates and other factors were different. Therefore, the etching amount was slightly different compared to Examples 1 and 2. Similarly, in other examples, when the experimental conditions were the same but the etching amount was different, the difference in experimental dates and other factors was the reason.

[0175] Comparative Example 2 is identical to Example 6 except that the first voltage is set to -2 V. In Comparative Example 2, the potential of the sidewall surface 942 of the microstructure 94 switches between -8 V and -2 V at a switching cycle of 6 seconds. In Comparative Example 2, the etching depth is approximately 11 nm, similar to Comparative Example 1 (refer to Table 1).

[0176] Comparing Examples 6-10 with Comparative Example 2, it can be seen that when performing steps S14 and S16 (switching the applied voltage), if both the first potential and the second potential of the sidewall surface 942 are negative (i.e., have the same sign) (Comparative Example 2), the etching rate of the film 96 to be processed in the recess 95 will not increase. On the other hand, if the first potential and the second potential of the sidewall surface 942 do not have the same sign, even if the absolute values ​​of the first potential and the second potential are different (Examples 6-8), the etching rate of the film 96 to be processed in the recess 95 will increase in approximately the same way as if the absolute values ​​of the first potential and the second potential were the same (Examples 9-10).

[0177] Furthermore, Comparative Example 2 is ultimately only a comparative example of etching the film 96 to be processed within the recess 95. Regarding the end face 941 of the microstructure 94 (see reference...) Figure 4 It was confirmed that by applying voltage as described above, the etching rate increased compared to Comparative Example 1 where no voltage was applied, on the treated film 96 (i.e., the treated film 96 outside the recess 95).

[0178] In Examples 11-14 shown in Table 3, the switching cycle of the applied voltage in steps S14 and S16 was changed, and the etching amount of the treated film 96 was measured. In Example 11, the applied voltage applied from the power supply unit 975 was a DC voltage, the second voltage was set to -1 V, and the first voltage was set to +1 V. Furthermore, the switching cycle of the applied voltage was 2 seconds. That is, in Example 11, the potential of the sidewall surface 942 of the microstructure 94 (i.e., the inner surface of the recess 95) switched between -1 V (the second potential) and +1 V (the first potential) with a switching cycle of 2 seconds. In Example 11, the etching amount was 20.5 nm.

[0179] Example 12 is identical to Example 11 except that the switching period is set to 6 seconds. In Example 12, the potential of the sidewall surface 942 of the microstructure 94 switches between -1 V (the second potential) and +1 V (the first potential) with a switching period of 6 seconds. In Example 12, the etching depth is 21.5 nm.

[0180] Example 13 is identical to Example 11 except that the switching period is set to 12 seconds. In Example 13, the potential of the sidewall surface 942 of the microstructure 94 switches between -1 V (the second potential) and +1 V (the first potential) with a switching period of 12 seconds. In Example 13, the etching depth is 22 nm.

[0181] Example 14 is identical to Example 11 except that the switching period is set to 18 seconds. In Example 14, the potential of the sidewall surface 942 of the microstructure 94 switches between -1 V (the second potential) and +1 V (the first potential) with an 18-second switching period. In Example 14, the etching depth is 19.5 nm.

[0182] In Comparative Example 1, as described above, the voltage application in steps S14 and S16 was omitted. In Comparative Example 1, as described above, the etching depth was 11 nm.

[0183] Comparing Examples 11-14 with Comparative Example 1, it can be seen that by performing steps S14 and S16 (switching the applied voltage), even when the switching cycle is different, the etching rate of the film 96 to be processed in the recess 95 will increase.

[0184] In Examples 15-17 shown in Table 4, the applied voltage in steps S14 and S16 was set to an AC voltage, and the frequency of this AC voltage was changed (i.e., the switching cycle was changed), and the etching amount of the treated film 96 was measured. In Example 15, the applied voltage from the power supply unit 975 was an AC voltage, the second voltage was set to -1 V, and the first voltage was set to +1 V. Furthermore, the frequency of the applied voltage was 0.5 Hz (i.e., the switching cycle was 2 seconds). That is, in Example 15, the potential of the sidewall surface 942 of the microstructure 94 (i.e., the inner surface of the recess 95) switched between -1 V (the second potential) and +1 V (the first potential) with a switching cycle of 2 seconds. In Example 15, the etching amount was 21 nm.

[0185] Example 16 is identical to Example 15 except that the frequency is set to 1 Hz (switching period: 1 second). In Example 16, the potential of the sidewall surface 942 of the microstructure 94 switches between -1 V (the second potential) and +1 V (the first potential) with a switching period of 1 second. In Example 16, the etching depth is 22 nm.

[0186] Example 17 is identical to Example 15 except that the frequency is set to 5 Hz (switching period: 0.2 seconds). In Example 17, the potential of the sidewall surface 942 of the microstructure 94 switches between -1 V (the second potential) and +1 V (the first potential) at a switching period of 0.2 seconds. In Example 17, the etching depth is 16.5 nm.

[0187] In Comparative Example 1, as described above, the voltage application in steps S14 and S16 was omitted. In Comparative Example 1, as described above, the etching depth was 11 nm.

[0188] Comparing Examples 15-17 with Comparative Example 1, it can be seen that by performing steps S14 and S16 (switching the applied voltage), the etching rate of the film 96 processed in the recess 95 increases even when the frequency of the AC voltage is different (i.e., the switching cycle is different). Furthermore, comparing Examples 15 and 11 (Table 3), it can be seen that when the first voltage, the second voltage, and the switching cycle are the same, the etching rate is substantially the same regardless of whether the applied voltage is DC or AC.

[0189] As described above, in Examples 18-28 and Comparative Example 3 shown in Tables 5-7, hydrogen peroxide water was used as the treatment solution. In Examples 18-22 shown in Table 5, the first and second voltages of the applied voltage in steps S14 and S16 were changed, and the etching amount of the treated film 96 was measured. In Example 18, the applied voltage from the power supply unit 975 was a DC voltage, the second voltage was set to -1 V, and the first voltage was set to +1 V. Furthermore, the switching cycle of the applied voltage was 2 seconds. That is, in Example 18, the potential of the sidewall surface 942 of the microstructure 94 (i.e., the inner surface of the recess 95) switched between -1 V (the second potential) and +1 V (the first potential) with a switching cycle of 2 seconds. In Example 18, the etching amount was 18 nm.

[0190] Example 19 is identical to Example 18 except that the second voltage is set to -2 V and the first voltage is set to +2 V. In Example 19, the potential of the sidewall surface 942 of the microstructure 94 switches between -2 V (the second potential) and +2 V (the first potential) at a switching cycle of 2 seconds. In Example 19, the etching depth is 18.5 nm.

[0191] Example 20 is identical to Example 18 except that the second voltage is set to -3 V and the first voltage is set to +3 V. In Example 20, the potential of the sidewall surface 942 of the microstructure 94 switches between -3 V (the second potential) and +3 V (the first potential) at a switching cycle of 2 seconds. In Example 20, the etching depth is 19 nm.

[0192] Example 21 is identical to Example 18 except that the second voltage is set to -5 V and the first voltage is set to +5 V. In Example 21, the potential of the sidewall surface 942 of the microstructure 94 switches between -5 V (the second potential) and +5 V (the first potential) at a switching cycle of 2 seconds. In Example 21, the etching depth is 22.5 nm.

[0193] Example 22 is identical to Example 18 except that the second voltage is set to -8 V and the first voltage is set to +8 V. In Example 22, the potential of the sidewall surface 942 of the microstructure 94 switches between -8 V (the second potential) and +8 V (the first potential) at a switching cycle of 2 seconds. In Example 22, the etching depth is 24.5 nm.

[0194] In Comparative Example 3, as described above, the voltage application in steps S14 and S16 was omitted. In Comparative Example 3, the etching depth was 15.5 nm.

[0195] Comparing Examples 18-22 with Comparative Example 3, it can be seen that by performing steps S14 and S16 (switching the applied voltage), the etching rate of the film 96 to be processed in the recess 95 will increase even when the applied voltage is different.

[0196] In Examples 23-25 ​​shown in Table 6, the switching cycle of the applied voltage in steps S14 and S16 was changed, and the etching amount of the treated film 96 was measured. In Example 23, the applied voltage from the power supply unit 975 was a DC voltage, the second voltage was set to -5 V, and the first voltage was set to +5 V. Furthermore, the switching cycle of the applied voltage was 0.5 seconds. That is, in Example 23, the potential of the sidewall surface 942 of the microstructure 94 (i.e., the inner surface of the recess 95) switched between -5 V (the second potential) and +5 V (the first potential) with a switching cycle of 0.5 seconds. In Example 23, the etching amount was 19 nm.

[0197] Example 24 is identical to Example 23 except that the switching period is set to 1 second. In Example 24, the potential of the sidewall surface 942 of the microstructure 94 switches between -5 V (the second potential) and +5 V (the first potential) with a switching period of 1 second. In Example 24, the etching depth is 21 nm.

[0198] Example 25 is identical to Example 23 except that the switching period is set to 2 seconds. In Example 25, the potential of the sidewall surface 942 of the microstructure 94 switches between -5 V (the second potential) and +5 V (the first potential) with a switching period of 2 seconds. In Example 25, the etching depth is 20 nm.

[0199] In Comparative Example 3, as described above, the voltage application in steps S14 and S16 was omitted. In Comparative Example 3, as described above, the etching depth was 15.5 nm.

[0200] Comparing Examples 23-25 ​​with Comparative Example 3, it can be seen that by performing steps S14 and S16 (switching the applied voltage), even when the switching cycle is different, the etching rate of the film 96 to be processed in the recess 95 will increase.

[0201] In Examples 26-28 shown in Table 7, the applied voltage in steps S14 and S16 was set to an AC voltage, and the frequency of this AC voltage was changed (i.e., the switching cycle was changed), and the etching amount of the treated film 96 was measured. In Example 26, the applied voltage from the power supply unit 975 was an AC voltage, the second voltage was set to -5 V, and the first voltage was set to +5 V. Furthermore, the frequency of the applied voltage was 1 Hz (i.e., the switching cycle was 1 second). That is, in Example 26, the potential of the sidewall surface 942 of the microstructure 94 (i.e., the inner surface of the recess 95) switched between -5 V (the second potential) and +5 V (the first potential) with a switching cycle of 1 second. In Example 26, the etching amount was 20.5 nm.

[0202] Example 27 is identical to Example 26 except that the frequency is set to 10 Hz (switching period: 0.1 seconds). In Example 27, the potential of the sidewall surface 942 of the microstructure 94 switches between -5 V (the second potential) and +5 V (the first potential) at a switching period of 0.1 seconds. In Example 27, the etching depth is 26 nm.

[0203] Example 28 is identical to Example 26 except that the frequency is set to 20 Hz (switching period: 0.05 seconds). In Example 28, the potential of the sidewall surface 942 of the microstructure 94 switches between -5 V (the second potential) and +5 V (the first potential) with a switching period of 0.05 seconds. In Example 28, the etching depth is 17.5 nm.

[0204] In Comparative Example 3, as described above, the voltage application in steps S14 and S16 was omitted. In Comparative Example 3, as described above, the etching depth was 15.5 nm.

[0205] Comparing Examples 26-28 with Comparative Example 3, it can be seen that by performing steps S14 and S16 (switching the applied voltage), the etching rate of the film 96 processed in the recess 95 increases even when the frequency of the AC voltage is different (i.e., the switching cycle is different). Furthermore, comparing Examples 26 and 24 (Table 6), it can be seen that when the first voltage, the second voltage, and the switching cycle are the same, the etching rate is substantially the same regardless of whether the applied voltage is DC or AC.

[0206] As described above, the substrate processing apparatus 1 includes a substrate holding section 21, a substrate rotation mechanism 23, a processing liquid supply section 5, a partition plate (i.e., a top plate 31), a partition plate moving mechanism (i.e., a top plate moving mechanism 33), a first electrode 61, a second electrode 62, a third electrode 63, and a power supply section 66. The substrate holding section 21 holds a substrate 9 with a film 96 to be processed on its upper surface 91 in a horizontal state. The substrate rotation mechanism 23 rotates the substrate holding section 21 about a central axis J1 in the vertical direction. The processing liquid supply section 5 supplies processing liquid for etching to the upper surface 91 of the substrate 9, bringing it into contact with the film 96 to be processed. The top plate 31 spans the entire upper surface 91 of the substrate 9 and faces the upper surface 91 of the substrate 9 in the vertical direction. The top plate moving mechanism 33 moves the top plate 31 relative to the substrate 9 in the vertical direction. The first electrode 61 is electrically connected to the substrate 9. The second electrode 62 is electrically connected to the processing liquid. The third electrode 63 is electrically connected to the processing liquid. The power supply unit 66 can apply voltages between the first electrode 61 and the second electrode 62, and between the first electrode 61 and the third electrode 63, respectively.

[0207] The processing liquid supply unit 5 includes a partition plate nozzle 51, a movable nozzle 52, and a nozzle moving mechanism 55. The partition plate nozzle 51 is fixed to the top plate 31 and sprays processing liquid from the lower surface 311 of the top plate 31 onto the upper surface 91 of the substrate 9. The movable nozzle 52 sprays processing liquid from above the substrate 9 toward the upper surface 91 of the substrate 9. The nozzle moving mechanism 55 moves the movable nozzle 52 horizontally above the substrate 9. With the gap between the lower surface 311 of the top plate 31 and the upper surface 91 of the substrate 9 filled with processing liquid to form a liquid film 50, the second electrode 62 provided on the lower surface 311 of the top plate 31 is electrically connected to the processing liquid by direct contact with the liquid film 50. The third electrode 63 is electrically connected to the processing liquid sprayed from the movable nozzle 52.

[0208] Therefore, in the substrate processing apparatus 1, both overall etching of the entire upper surface of the substrate 9 and local etching of desired areas (e.g., low etching rate areas) on the upper surface 91 of the substrate 9 can be performed. As a result, as described above, the time required to etch the substrate 9 can be shortened, and the uniformity of etching of the entire upper surface 91 of the substrate 9 can be improved.

[0209] As described above, the substrate processing apparatus 1 also includes a control unit 8. The control unit 8 controls the substrate rotation mechanism 23, the processing liquid supply unit 5, the top plate moving mechanism 33, and the power supply unit 66. In the substrate processing apparatus 1, it is preferable that, under the control of the control unit 8, a liquid film 50 of the processing liquid supplied from the partition plate nozzle 51 is formed in the gap between the lower surface 311 of the top plate 31 and the upper surface 91 of the substrate 9, and a voltage is applied between the first electrode 61 and the second electrode 62, thereby performing overall etching on the entire upper surface 91 of the substrate 9. Alternatively, it is preferable that, under the control of the control unit 8, the top plate 31 is retracted above the substrate 9, and the movable nozzle 52 is positioned above the rotating substrate 9 at a radially desired position (in this example, above a low etching rate region), and processing liquid is ejected from the movable nozzle 52, while a voltage is applied between the first electrode 61 and the third electrode 63, thereby performing local etching on a portion of the upper surface 91 of the substrate 9 (in this example, a low etching rate region). This reduces the time required to etch the substrate 9 and improves the uniformity of etching across the entire upper surface 91 of the substrate 9.

[0210] As described above, in the substrate processing apparatus 1, it is preferable to perform local etching after overall etching of the substrate 9 under the control of the control unit 8. This allows for the removal of the film 96 to a certain extent in low etching rate regions, followed by further removal of the film 96 through local etching. This enables efficient removal of the film 96 during local etching. Consequently, the uniformity of etching across the entire upper surface 91 of the substrate 9 can be improved more effectively and efficiently.

[0211] As described above, local etching is preferably performed on the radial center of the substrate 9. Thus, even if the etching rate of the center of the substrate 9 decreases due to factors such as the orientation of the nozzle 51 to the partition plate (i.e., there is no opposing second electrode 62) during overall etching, the uniformity of etching of the entire upper surface 91 of the substrate 9 can be improved.

[0212] As described above, local etching is preferably performed on the periphery of the substrate 9. Thus, even if the etching rate of the periphery of the substrate 9 decreases due to factors such as a drop in the temperature of the processing solution during overall etching, the uniformity of etching across the entire upper surface 91 of the substrate 9 can be improved.

[0213] As described above, preferably, in at least one of overall etching and partial etching, the voltage applied between the first electrode 61 and the second electrode 62 or the third electrode 63 repeatedly switches between different first and second voltages at a predetermined switching cycle. This causes the potential of the sidewall surface 942 of the recess 95 forming the pattern 93 on the substrate 9 to repeatedly switch between a first potential and a second potential less than the first potential. The first potential is 0 V or higher, and the second potential is 0 V or lower. Thus, as illustrated in Examples 1 to 28, the etching rate of the film 96 being processed within the recess 95 can be increased. The reason for this increased etching rate can be considered, for example, as described below.

[0214] In the first principle, by repeatedly switching the potential of the sidewall surface 942, water molecules and other substances adsorbed on the surface of the film 96 to be treated within the recess 95 can be better electrolyzed, and etchants such as hydrogen peroxide can be better adsorbed onto the film 96 to be treated. As a result, the etching rate of the film 96 to be treated can be increased.

[0215] Furthermore, in the second principle, by repeatedly switching the potential of the sidewall surface 942, the etched products (hereinafter also referred to as "etched products") that increase within the recess 95 can be better discharged out of the recess 95. As a result, the etchant becomes easier to enter the recess 95, thus increasing the etching rate of the treated film 96.

[0216] In the third principle, by repeatedly switching the potential of the sidewall surface 942, bubbles generated inside the recess 95 can be better discharged to the outside of the recess 95. As a result, the etchant becomes easier to enter the recess 95, thus increasing the etching rate of the treated film 96.

[0217] In the fourth principle, by repeatedly switching the potential of the sidewall surface 942, the complexes generated by etching that increase within the recess 95 can be better discharged out of the recess 95. As a result, the etchant becomes easier to enter the recess 95, thus increasing the etching rate of the treated film 96.

[0218] As described above, the voltage switching cycle is preferably 0.05 seconds or more. This allows for a further increase in the etching rate of the film 96 being processed within the recess 95. The reasons for this further increase in etching rate can be considered, for example, as described below.

[0219] In the first principle, when the switching cycle is less than 0.05 seconds, the applied voltage is switched before sufficient electrolysis of water molecules and the like adsorbed on the surface of the film 96 being treated, which may result in insufficient electrolysis of the water molecules and the like. Therefore, the adsorption of the etchant onto the film 96 being treated is hindered by water molecules and the like, and the increase in the etching rate may not be sufficient. On the other hand, when the switching cycle is 0.05 seconds or more, the electrolysis of water molecules and the like will proceed better, and the etching rate of the film 96 being treated will further increase.

[0220] In the second principle, when the switching cycle is less than 0.05 seconds, the applied voltage is switched before the etched product is fully discharged from the recess 95, resulting in insufficient discharge of the etched product from the recess 95. Therefore, the entry of the etchant into the recess 95 is hindered, and the increase in the etching rate may be insufficient. On the other hand, when the switching cycle is 0.05 seconds or more, the discharge of the etched product from the recess 95 is better, and the etching rate of the treated film 96 is further increased.

[0221] In the third principle, when the switching cycle is less than 0.05 seconds, the applied voltage is switched before the bubbles are fully discharged from the recess 95, which may result in insufficient discharge of the bubbles from the recess 95. Therefore, the entry of the etchant into the recess 95 is hindered, and the increase in the etching rate may be insufficient. On the other hand, when the switching cycle is 0.05 seconds or more, the discharge of bubbles from the recess 95 is better, and the etching rate of the treated film 96 is further increased.

[0222] In the fourth principle, when the switching cycle is less than 0.05 seconds, the applied voltage is switched before the complex is fully discharged out of the recess 95, which may result in insufficient discharge of the complex out of the recess 95. Therefore, the entry of the etchant into the recess 95 is hindered, and the increase in the etching rate may be insufficient. On the other hand, when the switching cycle is 0.05 seconds or more, the discharge of the complex out of the recess 95 will be better, and the etching rate of the treated film 96 will be further increased.

[0223] As described above, when the applied voltage is a DC voltage, the switching cycle is preferably 0.5 seconds or more. This allows for a better increase in the etching rate of the film 96 being processed.

[0224] As described above, when the applied voltage is an alternating current voltage, the switching cycle is preferably 0.2 seconds or more. This allows for a better increase in the etching rate of the film 96 being processed.

[0225] The configuration of the substrate processing apparatus 1 is not limited to the example described, and various modifications can be made. For example, in Figure 14 In the illustrated substrate processing apparatus 1a, the plurality of first electrodes 61 (refer to) that are disposed on the plurality of clamping pins 212 are replaced. Figure 2 A first electrode 61a is disposed on the upper surface of the base portion 211 of the substrate holding portion 21. The first electrode 61a is a conductive component that is approximately annular or approximately circular in shape and centered on the central axis J1. The first electrode 61a is formed, for example, of platinum (Pt) or glassy carbon (GC), in a substantially similar manner to the first electrode 61. In plan view, the outer diameter of the first electrode 61a is, for example, slightly smaller than the diameter of the substrate 9. Furthermore, in a plane, the outer diameter of the first electrode 61a may be larger than or approximately equal to the diameter of the substrate 9. The first electrode 61a, like the plurality of first electrodes 61, is electrically connected to the power supply portion 66 via the first transmission portion 64 and the second transmission portion 65. Furthermore, the shape and material of the first electrode 61a can be varied in various ways.

[0226] The upper surface 611 of the first electrode 61a protrudes from the upper surface of the base portion 211 and is not covered by the base portion 211. The upper surface 611 of the first electrode 61a spans approximately the entire lower surface 92 of the substrate 9 and is in direct surface contact with the lower surface 92 in the vertical direction. Thus, the first electrode 61a is electrically connected to the substrate 9. The upper surface 611 of the first electrode 61a spans approximately the entire lower surface 621 of the second electrode 62 and is in direct surface contact with the lower surface 621 through the substrate 9 in the vertical direction.

[0227] In the substrate processing apparatus 1a, a first electrode 61a is provided that makes surface contact with the lower surface 92 of the substrate 9 over a relatively large area. Therefore, compared to the substrate processing apparatus 1 where the first electrode 61 is electrically connected to the substrate 9 only at the periphery of the substrate 9, current concentration at the periphery of the substrate 9 is alleviated during the overall etching in steps S13 to S14. Furthermore, during the local etching in steps S15 to S16, regardless of the position of the movable nozzle 52, the lower end of the movable nozzle 52 and the first electrode 61a face each other in the vertical direction across the substrate 9. Therefore, local etching is performed more effectively regardless of the position of the movable nozzle 52. This allows for the suppression of the processed film 96 (see reference 1). Figure 4 The potential difference is generated due to the radial position of the substrate 9.

[0228] Furthermore, the first electrode 61a spans the entire circumferential direction centered on the central axis J1 and is in direct contact with the substrate 9. Therefore, it is also possible to suppress potential differences in the film 96 being processed due to its position on the substrate 9 along the circumferential direction (e.g., in the substrate processing apparatus 1, the angle between the circumferential direction and the clamping pin 212). As a result, the uniformity of the etching rate of the substrate 9 in both the radial and circumferential directions is improved.

[0229] In the substrate processing apparatus 1a, the first electrode 61a can also move vertically relative to the base portion 211. In this case, when the substrate 9 is placed into the substrate processing apparatus 1a and held by the substrate holding portion 21, the first electrode 61a can be separated from the substrate 9 downwards. After the substrate 9 is held by multiple clamping pins 212, the first electrode 61a can be raised vertically relative to the base portion 211 and come into direct contact with the lower surface 92 of the substrate 9. The mechanism for moving the first electrode 61a vertically relative to the base portion 211 can be, for example, an electric linear motor, a cylinder, or a ball screw and an electric rotary motor connected to the first electrode 61a.

[0230] As explained above, the substrate processing apparatus 1a includes a first electrode 61a disposed on the upper surface of the base portion 211 and in contact with the lower surface 92 of the substrate 9. This further improves the uniformity of the etching rate of the substrate 9.

[0231] Furthermore, in the substrate processing apparatus 1a, in addition to the first electrode 61a, a plurality of first electrodes 61 respectively disposed on the upper inner surface 213 of a plurality of clamping pins 212 may also be provided (see reference). Figure 2 In this case, the plurality of first electrodes 61, like the first electrode 61a, are electrically connected to the power supply unit 66 via the first transmission unit 64 and the second transmission unit 65. In steps S14 and S16, by applying voltage from the power supply unit 66, the first electrode 61a and the plurality of first electrodes 61 are brought to the same potential.

[0232] like Figure 14 As illustrated, in the substrate processing apparatus 1a, a heating section 25 for heating the substrate 9 from below may also be provided. The heating section 25 includes a heating plate 251 disposed inside the base portion 211 of the substrate holding portion 21. The heating plate 251 is disposed below the first electrode 61a disposed on the upper surface of the base portion 211. In other words, the first electrode 61a is disposed between the heating plate 251 built into the base portion 211 and the lower surface 92 of the substrate 9.

[0233] The heating plate 251 is a generally annular or generally circular plate-shaped component centered on the central axis J1. The outer diameter of the heating plate 251 is, for example, slightly smaller than the diameter of the substrate 9. The heating plate 251 is an electric heater formed by embedding electric heating wires (not shown) inside the heating plate body. By supplying electricity to these electric heating wires, the heating plate body, made of ceramic or the like, is heated.

[0234] In the substrate processing apparatus 1a, during the overall etching and partial etching in steps S13 to S16, the heating plate 251 disposed below the first electrode 61a is indirectly in contact with the lower surface 92 of the substrate 9 via the first electrode 61a. The substrate 9 is heated from below via the heating plate 251 and the first electrode 61a. The first electrode 61a is preferably formed of a material with relatively high thermal conductivity, such as glassy carbon.

[0235] In the substrate processing apparatus 1a, the substrate 9 is heated by the heating unit 25, thereby heating the film 96 to be processed (see reference). Figure 4 As the temperature increases, the etching rate of the film 96 being processed increases. Furthermore, the resistance of the substrate 9 decreases with increasing temperature; therefore, by heating the substrate 9, the applied voltage required to promote etching can be reduced. In addition, during the overall etching and local etching in steps S13 to S16, the temperature of the upper surface 91 of the substrate 9 is preferably set to, for example, 40°C to 100°C.

[0236] During the etching of substrate 9, as described above, differences in etching rate may occur due to the radial position on substrate 9. Therefore, in substrate processing apparatus 1a, the heating unit 25 can be controlled by the operation control unit 82 in a manner that varies the temperature of the heating plate 251 according to its radial position. In other words, by controlling the heating unit 25 through the operation control unit 82, the amount of heat per unit area supplied from the heating plate 251 to the lower surface 92 of substrate 9 is varied according to the radial distance on substrate 9 from the central axis J1.

[0237] Specifically, for example, within the heating plate body of the heating plate 251, a plurality of heating wires are arranged in a substantially concentric circle around the central axis J1. The power supplied to these heating wires can be controlled independently. In the heating plate 251, the temperature of the heating plate 251 is adjusted at each radial position by individually adjusting the power supplied to these heating wires. Thus, the heat per unit area imparted from the heating plate 251 to the lower surface 92 of the substrate 9 is adjusted at each radial position.

[0238] In the substrate processing apparatus 1a, for example, if the etching rate at the periphery of the substrate 9 becomes lower than the etching rate at the center of the substrate 9 after uniform heating, the heating section 25 is controlled to make the temperature at the periphery of the heating plate 251 higher than the temperature at the center of the heating plate 251. This improves the radial uniformity of the etching rate of the substrate 9.

[0239] As explained above, the substrate processing apparatus 1a also includes a heating section 25 that heats the substrate 9 from below. This allows the temperature of the substrate 9 to rise, thereby increasing the etching rate of the film 96 being processed.

[0240] As described above, the heating element 25 is preferably capable of varying the amount of heat applied to the lower surface 92 of the substrate 9 per unit area based on its distance from the center (i.e., the central axis J1) of the substrate 9. This improves the radial uniformity of the etching rate of the substrate 9.

[0241] exist Figure 15 In the illustrated substrate processing apparatus 1b, the third electrode 63 (see reference) is replaced. Figure 2 A third electrode 63b, with a different shape than the third electrode 63, is disposed on the movable nozzle 52. The third electrode 63b is mechanically connected and fixed to the lower end of the movable nozzle 52. The third electrode 63b is, for example, a generally annular and flat conductive component centered on the movable nozzle 52. In other words, the lower end of the movable nozzle 52, when viewed from above, is located at the center of the third electrode 63b. The third electrode 63b is, for example, fitted into the lower end of the movable nozzle 52. The third electrode 63b moves horizontally together with the movable nozzle 52 via the nozzle moving mechanism 55, and also moves vertically together with the movable nozzle 52.

[0242] Figure 15 In the example shown, the lower end of the movable nozzle 52 is located approximately at the same position as the lower surface 631b of the third electrode 63b in the vertical direction. The nozzle outlet located at the lower end of the movable nozzle 52 is located at the opening provided in the center of the lower surface 631b of the third electrode 63b, and faces the upper surface 91 of the substrate 9 in the vertical direction. Furthermore, the lower end of the movable nozzle 52 may be located either below or above the lower surface 631b of the third electrode 63b.

[0243] Viewed from above, the third electrode 63b is smaller than the upper surface 91 of the substrate 9. In other words, the outer diameter of the third electrode 63b is smaller than the diameter of the substrate 9. When the diameter of the substrate 9 is 300 mm, the outer diameter of the third electrode 63b is, for example, 20 mm to 100 mm. The lower surface 631b of the third electrode 63b spans approximately the entire lower surface 631b and faces the upper surface 91 of the substrate 9 in the vertical direction. The lower surface 631b of the third electrode 63b is a plane that is approximately parallel to the upper surface 91 of the substrate 9.

[0244] The third electrode 63b and the third electrode 63 (refer to) Figure 2 Similarly, it is mechanically and electrically connected to the power supply unit 66 via wires. The third electrode 63b, similar to the third electrode 63, is formed of a material with high chemical resistance and conductivity. For example, the third electrode 63b is formed of platinum or glassy carbon. Furthermore, the shape and material of the third electrode 63b can be varied.

[0245] The substrate 9 processing flow in substrate processing apparatus 1b is the same as that in steps S15-S16, except for the difference in the vertical position of the movable nozzle 52 during local etching. Figure 5 Steps S11 to S18 are largely the same. In the substrate processing apparatus 1b, after the processing liquid begins to be ejected from the movable nozzle 52 in step S15, the movable nozzle 52 and the third electrode 63b are lowered by the nozzle moving mechanism 55, and as... Figure 16 As shown, it approaches substrate 9 in the vertical direction. In the following description, Figure 16 The vertical positions of the movable nozzle 52 and the third electrode 63b shown are also referred to as the "etching positions".

[0246] With the movable nozzle 52 and the third electrode 63b in the etching position, the lower surface 631b of the third electrode 63b is slightly separated from the upper surface 91 of the rotating substrate 9 by an upward orientation. The vertical distance between the lower surface 631b of the third electrode 63b and the upper surface 91 of the substrate 9 is, for example, about 4 mm. The lower surface 631b of the third electrode 63b faces, for example, a low etching rate region of the upper surface 91 of the substrate 9 in the vertical direction.

[0247] The gap between the lower surface 631b of the third electrode 63b and the upper surface 91 of the substrate 9 is substantially entirely filled with processing liquid continuously ejected from the movable nozzle 52, thereby forming a liquid film 50b of the processing liquid. The liquid film 50b is formed, for example, across substantially the entire lower surface 631b of the third electrode 63b. The third electrode 63b is electrically connected to the etching processing liquid (i.e., the processing liquid ejected from the movable nozzle 52) that forms the liquid film 50b through direct contact with the upper surface of the liquid film 50b. Furthermore, the movable nozzle 52 can also swing substantially horizontally above a low etching rate region.

[0248] A portion of the treatment liquid supplied from the movable nozzle 52 to the substrate 9 is dispersed radially outward from the periphery of the substrate 9 by the centrifugal force generated by the rotation of the substrate 9, and is received by the cup portion 4. The rotational speed of the substrate 9 in steps S15 to S16 is, for example, 10 rpm or more, preferably 10 rpm to 1500 rpm.

[0249] With the movable nozzle 52 in the etching position, the entire upper surface 91 of the substrate 9 can be covered by the etching solution. Alternatively, if the upper surface 91 of the substrate 9 has high hydrophobicity, the processing solution can be interrupted in the area where the upper surface 91 of the substrate 9 does not overlap with the third electrode 63b when viewed from above, thus exposing the upper surface 91 to the ambient gas.

[0250] In step S16, a voltage is applied between the first electrode 61 and the third electrode 63b. This applies a voltage between the substrate 9 and the processing liquid below the third electrode 63b (i.e., the processing liquid in the low etch rate region). The applied voltage between the substrate 9 and the processing liquid is, for example, switched repeatedly between different first and second voltages at a predetermined switching cycle, for example, in a manner substantially similar to that described above. This results in the sidewall surface 942 of the microstructure 94 (refer to…) in the low etch rate region… Figure 4 The potential of the film 96 is repeatedly switched between the first potential and the second potential at the switching cycle. As a result, the etching rate of the film 96 in the recess 95 in the low etching rate region increases.

[0251] In the substrate processing apparatus 1b, after steps S15 to S16 are completed, the movable nozzle 52 and the third electrode 63b rise from the etching position, and for example, are located at... Figure 15 The position is shown. Then, as described above, rinsing and drying processes are performed (steps S17 to S18), at which point the processing of substrate 9 is completed.

[0252] As explained above, in the substrate processing apparatus 1b, the third electrode 63b is mechanically connected to the lower end of the movable nozzle 52 and faces the upper surface 91 of the substrate 9 in the vertical direction. The third electrode 63b is a flat plate-shaped component smaller than the upper surface 91 of the substrate 9. In the substrate processing apparatus 1b, local etching is performed with a liquid film 50b formed by filling the gap between the lower surface 631b of the third electrode 63b and the upper surface 91 of the substrate 9 with processing liquid. In the substrate processing apparatus 1b, compared to the case where the lower end of the movable nozzle 52 is not provided with the third electrode 63b, the area on the substrate 9 that can be simultaneously locally etched can be increased. As a result, the time required for local etching can be shortened.

[0253] Various modifications can be made to the substrate processing apparatuses 1, 1a, and 1b.

[0254] For example, the local etching in substrate processing apparatus 1, as described above, does not necessarily need to be performed on the central or peripheral portion of substrate 9; it can also be performed on desired radial locations on substrate 9. These desired locations can be one or more. The same applies to substrate processing apparatuses 1a and 1b.

[0255] In substrate processing apparatus 1, during the rinsing process in step S17, rinsing fluid may also be supplied to the upper surface 91 of substrate 9 from a nozzle different from movable nozzle 52. The same applies to substrate processing apparatuses 1a and 1b.

[0256] In substrate processing apparatus 1, the electrical connection between the first electrode 61 and the power supply unit 66 does not necessarily have to be non-contact. For example, the first electrode 61 and the power supply unit 66 can be mechanically and electrically connected via a slip ring or the like provided on the shaft 217. The same applies to substrate processing apparatuses 1a and 1b. In this case, the first transmission unit 64 and the second transmission unit 65 can also be omitted.

[0257] In substrate processing apparatus 1, the second electrode 62 can also be electrically connected to the power supply unit 66 in a non-contact manner via a wireless power supply element such as a magnetic coupling method or an electric field coupling method as described above. The same applies to substrate processing apparatuses 1a and 1b.

[0258] In substrate processing apparatus 1, the switching period of the applied voltage can also be less than 0.05 seconds. Furthermore, in substrate processing apparatus 1, as described above, it is not necessary to switch the applied voltage; the applied voltage can be kept constant during both overall etching and partial etching. The same applies to substrate processing apparatuses 1a and 1b.

[0259] The substrate holding portion 21 does not necessarily have to be a mechanical chuck, but can be a chuck with various structures. For example, the substrate holding portion 21 can also be a vacuum chuck that adsorbs and holds the substrate 9 by directly contacting the lower surface 92 of the substrate 9. In this case, for example, the upper surface of the vacuum chuck that contacts the lower surface 92 of the substrate 9 is a first electrode that is approximately circular, and the substrate 9 is electrically connected to the first electrode by directly contacting the lower surface 92 of the substrate 9 with the first electrode.

[0260] The substrate processing apparatuses 1, 1a, and 1b can also be used to process glass substrates used in flat panel displays such as liquid crystal displays or organic EL (electroluminescence) displays, or glass substrates used in other display devices, in addition to semiconductor substrates. Furthermore, the substrate processing apparatuses 1, 1a, and 1b can also be used to process substrates for optical discs, magnetic disks, magneto-optical discs, photomasks, ceramic substrates, and solar cells.

[0261] The components in the described implementation methods and variations can be appropriately combined as long as they do not contradict each other.

[0262] The invention has been described in detail, but the description above is illustrative and not limiting. Therefore, it can be said that various modifications and forms can be achieved without departing from the scope of the invention.

[0263] [Explanation of Symbols]

[0264] 1, 1a, 1b: Substrate processing apparatus

[0265] 5: Processing fluid supply unit

[0266] 8: Control Department

[0267] 9: Substrate

[0268] 21: Substrate holding section

[0269] 23: Substrate Rotation Mechanism

[0270] 25: Heating section

[0271] 31: Top plate

[0272] 33: Top plate moving mechanism

[0273] 50, 50b: Liquid film

[0274] 51: Partition plate nozzle

[0275] 52: Movable nozzle

[0276] 55: Nozzle moving mechanism

[0277] 61, 61a: First electrode

[0278] 62: Second electrode

[0279] 63, 63b: Third electrode

[0280] 66: Power Supply Section

[0281] 91: (Substrate) Upper surface

[0282] 96: The membrane being treated

[0283] 311: (Top plate) Lower surface

[0284] 621: (Lower surface of the second electrode)

[0285] 631b: (Lower surface of the third electrode)

[0286] J1: Central axis.

Claims

1. A substrate processing apparatus for etching a substrate, comprising: The substrate holding section holds the substrate with the film to be processed on its upper surface in a horizontal state; A substrate rotation mechanism that allows the substrate holding portion to rotate about a central axis in the vertical direction; The processing liquid supply unit supplies the processing liquid for etching to the upper surface of the substrate and brings it into contact with the film to be processed. A partition plate that spans the entire upper surface of the substrate and faces the upper surface of the substrate in the vertical direction; A partition plate moving mechanism that allows the partition plate to move relative to the substrate in a vertical direction; The first electrode is electrically connected to the substrate; The second and third electrodes are electrically connected to the treatment liquid; as well as The power supply unit is capable of applying voltages between the first electrode and the second electrode, and between the first electrode and the third electrode, respectively; and The processing fluid supply unit includes: A partition plate nozzle, fixed to the partition plate, sprays the treatment liquid from the lower surface of the partition plate toward the upper surface of the substrate; A movable nozzle sprays the treatment liquid from above the substrate toward the upper surface of the substrate; as well as A nozzle moving mechanism that allows the movable nozzle to move horizontally above the substrate; With a liquid film formed by filling the gap between the lower surface of the partition plate and the upper surface of the substrate with the processing liquid, the second electrode disposed on the lower surface of the partition plate is electrically connected to the processing liquid through direct contact with the liquid film. The third electrode is electrically connected to the treatment liquid ejected from the movable nozzle.

2. The substrate processing apparatus according to claim 1, further comprising: The control unit controls the substrate rotation mechanism, the processing liquid supply unit, the partition plate moving mechanism, and the power supply unit; and Under the control of the control unit, with a liquid film of the processing liquid supplied from the nozzle of the partition plate formed in the gap between the lower surface of the partition plate and the upper surface of the substrate, a voltage is applied between the first electrode and the second electrode, thereby etching the entire upper surface of the substrate. Under the control of the control unit, with the partition plate retracted above the substrate and the movable nozzle positioned radially above the rotating substrate at a desired position, the processing liquid is ejected from the movable nozzle. Simultaneously, a voltage is applied between the first electrode and the third electrode, thereby locally etching a portion of the upper surface of the substrate.

3. The substrate processing apparatus according to claim 2, wherein Under the control of the control unit, the local etching is performed after the overall etching of the substrate.

4. The substrate processing apparatus according to claim 2, wherein The local etching is performed on the radial center of the substrate.

5. The substrate processing apparatus according to claim 2, wherein The local etching is performed on the periphery of the substrate.

6. The substrate processing apparatus according to claim 2, wherein The third electrode is a flat plate-shaped component that is mechanically connected to the lower end of the movable nozzle, faces the upper surface of the substrate in the vertical direction, and is smaller than the upper surface of the substrate. The local etching is performed with a liquid film formed in the gap between the lower surface of the third electrode and the upper surface of the substrate, which is filled with the processing liquid.

7. The substrate processing apparatus according to claim 2, further comprising: A heating element is provided in the substrate holding portion to heat the substrate from below; and The heating element can vary the amount of heat applied to the lower surface of the substrate per unit area based on the distance between it and the center of the substrate.

8. The substrate processing apparatus according to any one of claims 2 to 7, wherein In at least one of the overall etching and the partial etching, the voltage applied between the first electrode and the second electrode or the third electrode repeatedly switches between different first and second voltages at a predetermined switching cycle, thereby causing the potential of the sidewall surface of the recess forming the pattern on the substrate to repeatedly switch between a first potential and a second potential lower than the first potential, and The first potential is above 0 V. The second potential is below 0 V.

9. The substrate processing apparatus according to claim 8, wherein The switching cycle is 0.05 seconds or more.

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