Film forming device

Abstract

To provide a film deposition apparatus which has a simple structure and can reduce a load on an electrolyte membrane due to the self-weight of a plating solution.SOLUTION: A film deposition apparatus 1 comprises: an anode 11; an electrolyte membrane 13 which is arranged between the anode 11 and a substrate 12 serving as a cathode; a liquid storage chamber 14 which stores the anode 11 and a plating solution S, and in which an opening 143 opened on the substrate 12 side is closed by the electrolyte membrane 13; and a power supply unit 16 which applies a voltage between the anode 11 and the substrate 12, wherein a metal film derived from metal ions in the plating solution S is deposited on a surface of the substrate 12 by applying a voltage while the electrolyte membrane 13 is in contact with the substrate 12. The liquid storage chamber 14 is rotatably formed so that the electrolyte membrane 13 faces upward and the electrolyte membrane 13 faces downward.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a film-forming apparatus, and particularly to a film-forming apparatus suitable for the solid-phase electrodeposition method.

Background Art

[0002] As a film-forming apparatus suitable for the solid-phase electrodeposition method, for example, as described in Patent Document 1 below, an electrolyte membrane disposed between a base material serving as an anode and a cathode, and a plating solution containing metal ions so as to contact the electrolyte membrane and the anode are provided. A liquid storage chamber for storing the plating solution, a power supply unit for applying a voltage between the anode and the base material, a supply piston for supplying the plating solution to the liquid storage chamber, and a discharge piston for discharging the plating solution from the liquid storage chamber are known. In this film-forming apparatus, by disposing the base material above the liquid storage chamber, the load on the electrolyte membrane due to the weight of the plating solution is reduced, and the oxygen gas generated from the anode is removed by controlling the supply piston and the discharge piston.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above-described film-forming apparatus, since the plating solution in the liquid storage chamber is constantly flowed using the supply piston and the discharge piston, a large amount of plating solution is required. In addition, by providing the supply piston and the discharge piston, there is a problem that the structure of the film-forming apparatus becomes complicated.

[0005] The present invention has been made to solve such technical problems, and an object thereof is to provide a film-forming apparatus having a simple structure and capable of reducing the load on the electrolyte membrane due to the weight of the plating solution.

Means for Solving the Problems

[0006] The film-forming apparatus according to the present invention comprises an anode, an electrolyte membrane disposed between the anode and a substrate which is the cathode, a liquid storage chamber which contains the anode and a plating solution and whose opening is closed by the electrolyte membrane, and a power supply unit which applies a voltage between the anode and the substrate, and is a film-forming apparatus which deposits a metal film derived from metal ions in the plating solution onto the surface of the substrate by applying a voltage while the electrolyte membrane is in contact with the substrate, and is characterized in that the liquid storage chamber is rotatably formed so as to have a state in which the electrolyte membrane faces upward and a state in which the electrolyte membrane faces downward.

[0007] In the film deposition apparatus according to the present invention, the liquid storage chamber is rotatably formed to have two states: one in which the electrolyte membrane faces upward and another in which the electrolyte membrane faces downward. Therefore, by rotating the liquid storage chamber when changing the substrate, the electrolyte membrane can be positioned upward, and by changing the substrate in this state, the load on the electrolyte membrane due to the weight of the plating solution can be reduced. On the other hand, by rotating the liquid storage chamber during film deposition, the electrolyte membrane can be positioned downward, and by performing film deposition on the substrate in this state, the substrate can be pressed using the weight of the plating solution, thereby ensuring the quality of the film deposition. Furthermore, compared to conventional cases where a supply piston and discharge piston are provided, only a mechanism for rotating the liquid storage chamber is required, resulting in a simpler apparatus structure. As a result, the load on the electrolyte membrane due to the weight of the plating solution can be reduced with a simple structure.

[0008] In the film deposition apparatus according to the present invention, it is preferable that the anode is formed in a mesh-like manner or has a plurality of through holes. In this way, oxygen gas generated at the anode when voltage is applied can escape through the gaps in the anode, thereby suppressing the accumulation of oxygen gas on the electrolyte membrane surface. As a result, the impact of oxygen gas accumulation on film deposition quality can be suppressed.

[0009] Furthermore, in the film-forming apparatus according to the present invention, it is preferable to further provide a support frame that is detachable from the liquid storage chamber, which supports the electrolyte membrane and the substrate from the opposite side of the anode, with respect to the electrolyte membrane and the substrate which are arranged in contact with each other. In this way, the electrolyte membrane and the substrate which are arranged in contact with each other can be attached to the liquid storage chamber with the support frame, thereby preventing the electrolyte membrane and the substrate from detaching or falling when the liquid storage chamber is rotated, and preventing the electrolyte membrane and the substrate from detaching or falling when the electrolyte membrane is facing downwards. [Effects of the Invention]

[0010] According to the present invention, it is possible to reduce the load on the electrolyte membrane due to the weight of the plating solution with a simple structure. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic cross-sectional view showing a film deposition apparatus according to an embodiment. [Figure 2] This is a perspective view showing the liquid storage chamber, electrolyte membrane, substrate, and support frame. [Figure 3] This is a schematic cross-sectional view illustrating a film deposition method using a film deposition apparatus. [Figure 4] This is a schematic cross-sectional view illustrating a film deposition method using a film deposition apparatus. [Figure 5] This is a schematic cross-sectional view illustrating a film deposition method using a film deposition apparatus. [Modes for carrying out the invention]

[0012] Hereinafter, embodiments of the film deposition apparatus according to the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant explanations are omitted. In the following description, "up" refers to the direction away from the mounting stage which is positioned opposite the liquid containment chamber, and "down" refers to the direction approaching the mounting stage.

[0013] Figure 1 is a schematic cross-sectional view showing a film deposition apparatus according to an embodiment, and Figure 2 is a perspective view showing the liquid storage chamber, electrolyte membrane, substrate and support frame. The film deposition apparatus 1 of this embodiment is a plating apparatus for forming (in other words, coating) a metal film on the surface of a substrate 12 using solid-phase electrodeposition. As shown in Figure 1, the film deposition apparatus 1 comprises an anode 11, a substrate 12 which is the cathode, an electrolyte membrane 13 disposed between the anode 11 and the substrate 12, a liquid storage chamber 14 which contains the anode 11 and the plating solution S, a mounting table 15 which is disposed below the liquid storage chamber 14 and is superimposed on the lower surface of the substrate 12, and a power supply unit 16 which applies a voltage between the anode 11 and the substrate 12.

[0014] The anode 11 is formed in the shape of a flat plate from a metallic material and is positioned inside the liquid storage chamber 14 in a manner that allows it to come into contact with the plating solution S filled in the liquid storage chamber 14. As shown in Figure 1, the anode 11 is suspended from the ceiling of the liquid storage chamber 14 via a conductive member 17 and is electrically connected to the positive electrode of the power supply unit 16 via the conductive member 17 and a conductor. This anode 11 may be a soluble anode made of the same material as the metal film formed on the substrate 12 (e.g., copper), or an anode made of a material insoluble in the plating solution S (e.g., titanium).

[0015] In this embodiment, the anode 11 is formed in a mesh-like structure or has multiple through holes in order to allow oxygen gas generated at the anode 11 when a voltage is applied to escape. For example, the anode 11 is a copper plate with multiple through holes, or a copper mesh body with multiple meshes.

[0016] The base material 12 is, for example, a plate-shaped member. The base material 12 may be made of a metal material such as copper, silver, gold, nickel, aluminum, or iron, or a metal layer made of the above metal may be coated on the surface of a resin, ceramic, or the like. The base material 12 is attached below the liquid storage chamber 14 by a support frame 18, which will be described later. Furthermore, when the base material 12 comes into contact with the mounting base 15 as the liquid storage chamber 14 descends, it is electrically connectable to the negative electrode of the power supply unit 16 via the mounting base 15.

[0017] The electrolyte membrane 13 is a so-called solid electrolyte membrane and has a certain flexibility. This electrolyte membrane 13 is disposed below the liquid storage chamber 14 so as to close an opening 143 (described later) of the liquid storage chamber 14. And the lower surface of the electrolyte membrane 13 is in close contact with the upper surface of the above-described base material 12. The electrolyte membrane 13 is attached to the liquid storage chamber 14 by the support frame 18 together with the base material 12 in a state of being in close contact with the base material 12.

[0018] The electrolyte membrane 13 impregnates (contains) metal ions contained in the plating solution S therein by contacting the plating solution S accommodated in the liquid storage chamber 14. And when a voltage is applied, a metal derived from the metal ions is deposited on the surface of the base material 12 in close contact with it.

[0019] Examples of the material of the electrolyte membrane 13 include fluororesins such as Nafion (registered trademark) manufactured by DuPont, hydrocarbon resins, polyamic acid resins, and resins having an ion exchange function such as Selemion (CMV, CMD, CMF series) manufactured by Asahi Glass Co., Ltd. The thickness of the electrolyte membrane 13 is, for example, 5 to 200 μm.

[0020] The liquid storage chamber 14 has a shape in which both axial ends of a semi-cylindrical member are closed, and is formed of a material insoluble in the plating solution S. Specifically, the liquid storage chamber 14 has a main body portion 141 having a semi-circular cross-section and a pair of side end portions 142 disposed so as to close both side ends of the main body portion 141. Also, as shown in FIG. 1, the liquid storage chamber 14 has an opening 143 that opens toward the mounting table 15 side. The opening 143 is closed by the above-described electrolyte membrane 13. The above-described anode 11 is suspended from the ceiling of the main body portion 141. And the space surrounded by the main body portion 141, the side end portion 142, and the electrolyte membrane 13 constitutes a space for accommodating the plating solution S.

[0021] In the liquid storage chamber 14 of the present embodiment, the anode 11 and the electrolyte membrane 13 are arranged so as to be separated from each other and are in a non-contact state. However, when the liquid storage chamber 14 is filled with the plating solution S, the anode 11 and the electrolyte membrane 13 will contact each other through the plating solution S.

[0022] In addition, the liquid storage chamber 14 is provided with a supply channel 14a through which the plating solution S is supplied and a discharge channel 14b through which the plating solution S is discharged. The liquid storage chamber 14 is connected to the tank 19 and the pump 20 via pipes. Then, the plating solution S sent out from the tank 19 by the pump 20 flows into the liquid storage chamber 14 from the supply channel 14a, is discharged from the discharge channel 14b, and returns to the tank 19. Further, a pressure regulating valve 21 is provided on the downstream side of the discharge channel 14b, and the plating solution S in the liquid storage chamber 14 can be pressurized at a predetermined pressure by the pressure regulating valve 21 and the pump 20.

[0023] In addition, a three-way valve 22 is provided between the tank 19 and the pump 20. The three-way valve 22 also has a passage for taking in air in addition to the passages communicating with the tank 19 and the passages communicating with the pump 20. That is, in the three-way valve 22, when the passages communicating with the tank 19 and the passages communicating with the pump 20 are in communication, the plating solution S stored in the tank 19 is supplied into the liquid storage chamber 14 by driving the pump 20. On the other hand, in the three-way valve 22, when the passage for taking in air and the passage communicating with the pump 20 are in communication, air is supplied into the liquid storage chamber 14 by driving the pump 20. The supply of air to the liquid storage chamber 14 is used to discharge the plating solution S in the liquid storage chamber 14. Here, instead of air, other gases stored in a gas cylinder connected via the three-way valve 22 may be used.

[0024] Furthermore, the supply channel 14a of the liquid storage chamber 14 is connected to an open channel that is opened to the atmosphere via a shut-off valve 23.

[0025] The plating solution S is a liquid containing the metal of the metal film to be formed in an ionic state, and examples of such metals include copper, nickel, silver, or tin. The plating solution S is an aqueous solution obtained by dissolving (ionizing) these metals with an acid such as nitric acid, phosphoric acid, succinic acid, sulfuric acid, or pyrophosphate. For example, if the metal is nickel, the plating solution S could be an aqueous solution of nickel nitrate, nickel phosphate, nickel succinate, nickel sulfate, nickel pyrophosphate, or nickel sulfamate. If the metal is copper, the plating solution S could be an aqueous solution containing copper sulfate, copper pyrophosphate, etc.

[0026] Furthermore, the film deposition apparatus 1 is equipped with a support frame 18. The support frame 18 supports the electrolyte membrane 13 and the substrate 12, which are arranged in contact with each other, from the opposite side of the anode 11, and is detachably positioned in the liquid containment chamber 14. As shown in Figure 2, the support frame 18 has a rectangular frame-shaped first frame 181 that contacts and supports the peripheral edges of the electrolyte membrane 13 and the substrate 12, and a second frame 182 that rises from the first frame 181 and runs along the side end 142 of the liquid containment chamber 14.

[0027] The first frame 181 has an area larger than the area of ​​the mounting surface 151 (described later) of the mounting base 15 so as not to interfere with the overlapping of the lower surface of the substrate 12 and the mounting surface 151 of the mounting base 15 (see Figure 1). The second frame 182 is detachably fixed to the outer wall of the side end 142 of the liquid storage chamber 14, for example, by screws. The first frame 181 and the second frame 182 are integrally formed from, for example, a hard resin material so as not to affect the film formation on the substrate 12.

[0028] The mounting base 15 is made of a conductive material and is positioned below the liquid storage chamber 14 so as to face the base material 12 attached to the liquid storage chamber 14. The mounting base 15 has a mounting surface 151 that can be superimposed on the lower surface of the base material 12. The mounting base 15 is also electrically connected to the negative electrode of the power supply unit 16 via a conductor.

[0029] Furthermore, the film-forming apparatus 1 of this embodiment is equipped with a liquid-containing chamber moving device 24 that moves the liquid-containing chamber 14 so that it has two states: one in which the substrate 12, which is attached below the liquid-containing chamber 14, is brought close to the mounting table 15 and overlapped with the mounting surface 151, and another in which the substrate 12 is pulled away from the mounting surface 151.

[0030] The storage chamber moving device 24 is positioned, for example, above the liquid storage chamber 14 and consists of a hydraulic or pneumatic cylinder, an electric actuator, a linear guide, and a motor. By driving the storage chamber moving device 24, the liquid storage chamber 14 can be brought closer to the mounting base 15 so that the base material 12 attached below the liquid storage chamber 14 is aligned with the mounting surface 151. Conversely, by driving the storage chamber moving device 24, the liquid storage chamber 14 can be moved away from the mounting base 15 so that the base material 12 is away from the mounting surface 151.

[0031] Furthermore, in this embodiment, the liquid storage chamber 14 is rotatably formed so as to have a state in which the electrolyte membrane 13 faces upward and a state in which the electrolyte membrane 13 faces downward. Specifically, in the liquid storage chamber 14, a pair of support shafts 144 are fixed to each of the side ends 142. The liquid storage chamber 14 is rotatably supported on a support base (not shown) via the support shafts 144 and rotates under the drive of a rotation mechanism 25.

[0032] The configuration of the rotating mechanism 25 is not particularly limited, as long as it can rotate the liquid storage chamber 14 so that the electrolyte membrane 13 faces upward and the electrolyte membrane 13 faces downward. In this embodiment, the rotating mechanism 25 is configured to have a motor 251 and an endless belt 252 stretched between the rotating shaft of the motor 251 and the support shaft 144.

[0033] The following describes the film deposition method using the film deposition apparatus 1 of this embodiment, based on Figures 3 to 5.

[0034] As shown in Figure 3(a), the substrate 12 to be film-formed is attached to the liquid storage chamber 14. Specifically, first, the liquid storage chamber 14 is positioned so that the electrolyte membrane 13, with its opening 143 closed, faces upward. Next, the substrate 12 is placed on top of the electrolyte membrane 13 so that it is in contact with the electrolyte membrane 13. Then, the support frame 18 is fitted into the liquid storage chamber 14 so that it is placed over the substrate 12, and the second frame 182 of the support frame 18 is fixed to the side end 142 of the liquid storage chamber 14 with screws. In this way, the electrolyte membrane 13 and the substrate 12, which are positioned in contact with each other, are attached to the liquid storage chamber 14 via the support frame 18.

[0035] Next, as shown in Figure 3(b), the liquid storage chamber 14 is rotated by the rotation mechanism 25 so that the electrolyte membrane 13 faces downwards.

[0036] Next, the liquid storage chamber 14 is lowered using the storage chamber transfer device 24 so that the lower surface of the substrate 12 is aligned with the mounting surface 151 of the mounting table 15 (see Figure 4(a)). After the lower surface of the substrate 12 is aligned with the mounting surface 151 of the mounting table 15, voltage application is started. That is, the power supply unit 16 is used to apply voltage between the anode 11 and the substrate 12, which is the cathode.

[0037] When a voltage is applied, metal ions originating from metal deposits are deposited on the surface of the cathode substrate 12, and a metal film is formed on the surface of the substrate 12 (more specifically, the surface of the substrate 12 that is in contact with the electrolyte membrane 13). As shown in Figure 4(b), during film formation (in other words, when voltage is applied), the oxygen gas generated at the anode 11 passes through the gaps inside the electrolyte membrane 13 due to buoyancy and collects at the ceiling of the liquid containment chamber 14.

[0038] Then, once a metal film of the desired thickness is formed, the voltage application is terminated.

[0039] Next, without draining the plating solution S from the liquid storage chamber 14, the storage chamber moving device 24 raises the liquid storage chamber 14 so that the substrate 12 is separated from the mounting table 15. Once the liquid storage chamber 14 is raised to a predetermined height, the rotating mechanism 25 rotates the liquid storage chamber 14 so that the electrolyte membrane 13 faces upward (see Figure 5(a)).

[0040] Next, the substrate 12 is replaced. Specifically, as shown in Figure 5(b), after removing the support frame 18 from the liquid containment chamber 14, the film-deposited substrate 12 is removed from the electrolyte membrane 13. Subsequently, as shown in Figure 3(a) above, the substrate 12 to be film-deposited next is placed on the electrolyte membrane 13 and fixed with the support frame 18. When film-depositing on both sides of the substrate 12, the film-deposited side is turned over so that the side to be film-deposited is in contact with the substrate 12, and the substrate 12 is placed on the electrolyte membrane 13. After that, the steps shown in Figures 3(b) to 5(b) above can be repeated.

[0041] In the film deposition apparatus 1 of this embodiment, the liquid storage chamber 14 is rotatably formed to have two states: one in which the electrolyte membrane 13 faces upward and another in which the electrolyte membrane 13 faces downward. For example, when replacing the substrate 12, the liquid storage chamber 14 is rotated to a state in which the electrolyte membrane 13 faces upward, and by replacing the substrate 12 in this state, the load on the electrolyte membrane 13 due to the weight of the plating solution S is reduced, and stretching (also called bending) of the electrolyte membrane 13, damage to the electrolyte membrane 13, etc. caused by the load can be prevented. Therefore, leakage of the plating solution S due to abnormalities such as damage to the electrolyte membrane 13 can be prevented.

[0042] Furthermore, by rotating the liquid storage chamber 14 during film formation, the electrolyte membrane 13 is positioned downwards. By forming the film on the substrate 12 in this state, the substrate 12 can be pressed against the mounting table 15 using the weight of the plating solution S. Therefore, film formation defects can be prevented, and the quality of the film can be ensured. Moreover, compared to conventional systems that have supply and discharge pistons, only a rotating mechanism 25 for rotating the liquid storage chamber 14 is required, simplifying the structure of the apparatus. As a result, the load on the electrolyte membrane due to the weight of the plating solution S can be reduced with a simple structure.

[0043] Furthermore, since the anode 11 is formed in a mesh-like structure or in a plate-like structure with multiple through-holes, the oxygen gas generated in the anode 11 when voltage is applied can escape through the gaps within the anode 11. This suppresses the accumulation of oxygen gas on the surface of the electrolyte membrane 13, thereby preventing film formation defects caused by oxygen gas accumulation.

[0044] Furthermore, the film deposition apparatus 1 supports the electrolyte membrane 13 and substrate 12, which are placed in contact with each other, from the opposite side of the anode 11, and also includes a support frame 18 that can be attached to and removed from the liquid storage chamber 14. This makes it possible to attach the electrolyte membrane 13 and substrate 12, which are placed in contact with each other, to the liquid storage chamber 14 with the support frame 18, thereby preventing the electrolyte membrane 13 and substrate 12 from detaching or falling when the liquid storage chamber 14 rotates, and preventing the electrolyte membrane 13 and substrate 12 from detaching or falling when the electrolyte membrane 13 is facing downwards.

[0045] Although embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above, and various design modifications can be made without departing from the spirit of the invention as described in the claims. For example, instead of the support frame 18, a jig that can clamp the peripheral edges of the electrolyte membrane 13 and the base material 12 may be used. [Explanation of Symbols]

[0046] 1: Film deposition apparatus, 11: Anode, 12: Substrate, 13: Electrolyte membrane, 14: Liquid containment chamber, 14a: Supply channel, 14b: Discharge channel, 15: Mounting platform, 16: Power supply unit, 17: Conductive member, 18: Support frame, 19: Tank, 20: Pump, 21: Pressure regulating valve, 22: Three-way valve, 23: Gate valve, 24: Containsment chamber moving device, 25: Rotating mechanism, 141: Main body, 142: Side end, 143: Opening, 144: Support shaft, 151: Mounting surface, 181: First frame, 182: Second frame, 251: Motor, 252: Endless belt

Claims

1. A film-forming apparatus comprising an anode, an electrolyte membrane disposed between the anode and a substrate which is the cathode, a liquid storage chamber containing the anode and a plating solution, the opening of which is sealed by the electrolyte membrane, and a power supply unit for applying a voltage between the anode and the substrate, wherein a metal film derived from metal ions in the plating solution is formed on the surface of the substrate by applying a voltage while the electrolyte membrane is in contact with the substrate, The film-forming apparatus is characterized in that the liquid-containing chamber is rotatably formed so as to have a state in which the electrolyte membrane faces upward and a state in which the electrolyte membrane faces downward.

2. The film deposition apparatus according to claim 1, wherein the anode is formed in a mesh-like manner or has a plurality of through holes.

3. The film-forming apparatus according to claim 1 or 2, further comprising a support frame that is detachable from the liquid-containing chamber, supporting the electrolyte membrane and the substrate from the opposite side of the anode, with respect to the electrolyte membrane and the substrate which are arranged in contact with each other.

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