Film deposition apparatus

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 formation apparatus, and more particularly to a film formation apparatus suitable for solid phase electrodeposition. [Background technology]

[0002] As a film formation apparatus suitable for the solid-phase electrodeposition method, for example, as described in the following Patent Document 1, there is known an apparatus including an electrolyte membrane disposed between an anode and a substrate serving as a cathode, a liquid storage chamber that stores a plating solution containing metal ions so as to contact the electrolyte membrane and the anode, a power supply unit that applies a voltage between the anode and the substrate, a supply piston that supplies the plating solution to the liquid storage chamber, and a discharge piston that discharges the plating solution from the liquid storage chamber. In this film formation apparatus, the substrate is disposed above the liquid storage chamber to reduce the load on the electrolyte membrane due to the weight of the plating solution, while the supply piston and discharge piston are controlled to remove oxygen gas generated from the anode. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-154855 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned film forming apparatus, a large amount of plating solution is required to keep the plating solution in the solution containing chamber constantly flowing using the supply piston and the discharge piston, and in addition, the provision of the supply piston and the discharge piston causes 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 has an object to provide a membrane forming apparatus having a simple structure that can reduce the load on the electrolyte membrane caused by the weight of the plating solution. [Means for solving the problem]

[0006] The film formation apparatus of the present invention includes an anode, an electrolyte membrane disposed between the anode and a substrate which is a cathode, a liquid storage chamber which contains the anode and a plating solution and has an opening which is blocked by the electrolyte membrane, and a power supply unit which applies a voltage between the anode and the substrate, and which forms a metal film derived from metal ions in the plating solution on 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 formed to be rotatable so that the electrolyte membrane can face up and can face down.

[0007] In the film forming apparatus according to the present invention, the liquid storage chamber is formed to be rotatable so that the electrolyte membrane faces upward and downward. Therefore, when replacing the substrate, the liquid storage chamber is rotated to make the electrolyte membrane face upward, and the substrate is replaced in this state, thereby reducing the load on the electrolyte membrane due to the weight of the plating solution. On the other hand, when forming a film, the liquid storage chamber is rotated to make the electrolyte membrane face downward, and the substrate is formed in this state, so that the substrate can be pressed using the weight of the plating solution, thereby ensuring the quality of the film formation. In addition, compared to the case where a supply piston and a discharge piston are provided as in the conventional case, it is only necessary to provide a mechanism for rotating the liquid storage chamber, and the structure of the apparatus is simplified. 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 forming apparatus according to the present invention, the anode is preferably formed in a mesh shape or formed to have a plurality of through holes. In this way, oxygen gas generated at the anode when a voltage is applied can be released through the gaps in the anode, so that retention of oxygen gas on the electrolyte membrane surface can be suppressed. As a result, the effect of oxygen gas retention on the film forming quality can be suppressed.

[0009] In addition, in the film forming apparatus according to the present invention, it is preferable to further include a support frame that supports the electrolyte membrane and the substrate from the opposite side of the anode, and is detachable from the liquid containing chamber, for the electrolyte membrane and the substrate arranged in contact with each other. In this way, the electrolyte membrane and the substrate arranged in contact with each other can be attached to the liquid containing chamber by the support frame, and therefore it is possible to prevent the electrolyte membrane and the substrate from detaching or falling when the liquid containing chamber is rotated, and to prevent the electrolyte membrane and the substrate from detaching or falling when the electrolyte membrane faces downward. Effect of the Invention

[0010] According to the present invention, the load on the electrolyte membrane caused by the weight of the plating solution can be reduced with a simple structure. [Brief description of the drawings]

[0011] [Figure 1] 1 is a schematic cross-sectional view showing a film forming apparatus according to an embodiment. [Diagram 2] 2 is a perspective view showing a liquid storage chamber, an electrolyte membrane, a base material, and a support frame. FIG. [Diagram 3] 1A to 1C are schematic cross-sectional views for explaining a film forming method using a film forming apparatus. [Figure 4] 1A to 1C are schematic cross-sectional views for explaining a film forming method using a film forming apparatus. [Diagram 5] 1A to 1C are schematic cross-sectional views for explaining a film forming method using a film forming apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of a film forming apparatus according to the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are given the same reference numerals, and duplicated explanations will be omitted. In the following description, "upper" refers to the direction away from the mounting table arranged opposite the liquid storage chamber, and "lower" refers to the direction approaching the mounting table.

[0013] Fig. 1 is a schematic cross-sectional view showing a film forming apparatus according to an embodiment, and Fig. 2 is a perspective view showing a liquid storage chamber, an electrolyte membrane, a substrate, and a support frame. The film forming 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 a solid-phase electrodeposition method. As shown in Fig. 1, the film forming apparatus 1 includes an anode 11, a substrate 12 serving as a cathode, an electrolyte membrane 13 disposed between the anode 11 and the substrate 12, a liquid storage chamber 14 for storing the anode 11 and a plating solution S, a mounting table 15 disposed below the liquid storage chamber 14 and overlapped with the lower surface of the substrate 12, and a power supply unit 16 for applying a voltage between the anode 11 and the substrate 12.

[0014] The anode 11 is made of a metal material and formed into a flat plate shape, and is disposed inside the liquid containing chamber 14 in a state in which it can come into contact with the plating solution S filled in the liquid containing chamber 14. As shown in Fig. 1, the anode 11 is suspended from the ceiling of the liquid containing 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. The anode 11 may be either a soluble anode made of the same material (e.g., copper) as the metal coating formed on the substrate 12, or an anode made of a material (e.g., titanium) that is insoluble in the plating solution S.

[0015] In this embodiment, the anode 11 is formed in a mesh shape or has a plurality of through holes to allow escape of oxygen gas generated at the anode 11 when a voltage is applied. For example, the anode 11 is a copper plate having a plurality of through holes, or a copper mesh having a plurality of meshes.

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

[0017] The electrolyte membrane 13 is a so-called solid electrolyte membrane, and has a certain degree of flexibility. The 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. The lower surface of the electrolyte membrane 13 is in close contact with the upper surface of the above-mentioned base material 12. The electrolyte membrane 13 is attached to the liquid storage chamber 14 together with the base material 12 by a support frame 18 in a state of being in close contact with the base material 12.

[0018] The electrolyte membrane 13 is brought into contact with the plating solution S contained in the liquid containing chamber 14, so that the electrolyte membrane 13 is impregnated (contains) therein the metal ions contained in the plating solution S. Then, when a voltage is applied, metal derived from the metal ions is deposited on the surface of the base material 12 that is in close contact with the electrolyte membrane 13.

[0019] Examples of materials for the electrolyte membrane 13 include fluorine-based resins such as Nafion (registered trademark) manufactured by DuPont, hydrocarbon-based 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 containing chamber 14 has a shape of a semi-cylindrical member with both axial ends closed, and is formed of a material insoluble in the plating solution S. Specifically, the liquid containing chamber 14 has a main body 141 having a semicircular cross section, and a pair of side ends 142 arranged to close both ends of the main body 141. As shown in FIG. 1, the liquid containing chamber 14 has an opening 143 that opens toward the mounting table 15. The opening 143 is closed by the electrolyte membrane 13. The anode 11 is suspended from the ceiling of the main body 141. The space surrounded by the main body 141, the side ends 142, and the electrolyte membrane 13 constitutes a space for containing the plating solution S.

[0021] In the liquid storage chamber 14 of this embodiment, the anode 11 and the electrolyte membrane 13 are arranged apart from each other and are in a non-contact state, but when the plating solution S is filled into the liquid storage chamber 14, the anode 11 and the electrolyte membrane 13 come into contact with each other via the plating solution S.

[0022] The liquid storage chamber 14 is provided with a supply flow path 14a through which the plating solution S is supplied and a discharge flow path 14b through which the plating solution S is discharged. The liquid storage chamber 14 is connected to a tank 19 and a pump 20 via piping. The plating solution S discharged from the tank 19 by the pump 20 flows into the liquid storage chamber 14 from the supply flow path 14a, and is discharged from the discharge flow path 14b and returned to the tank 19. A pressure regulating valve 21 is provided downstream of the discharge flow path 14b, and the plating solution S in the liquid storage chamber 14 can be pressurized to a predetermined pressure by the pressure regulating valve 21 and the pump 20.

[0023] A three-way valve 22 is provided between the tank 19 and the pump 20. The three-way valve 22 has a passage communicating with the tank 19 and a passage communicating with the pump 20, as well as a passage for taking in air. That is, when the passage communicating with the tank 19 and the passage communicating with the pump 20 are connected in the three-way valve 22, the plating solution S stored in the tank 19 is supplied to the inside of the liquid storage chamber 14 by driving the pump 20. On the other hand, when the passage for taking in air and the passage communicating with the pump 20 are connected in the three-way valve 22, air is supplied to the inside of 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 from the liquid storage chamber 14. Note that, instead of air, other gases stored in a gas cylinder connected via the three-way valve 22 may be used.

[0024] Furthermore, the supply flow path 14a of the liquid containing chamber 14 is connected to an open path that is open to the atmosphere via a gate valve 23.

[0025] The plating solution S is a solution containing the metal of the metal film to be formed in an ion state, and examples of the metal include copper, nickel, silver, and tin. The plating solution S is an aqueous solution in which these metals are dissolved (ionized) with an acid such as nitric acid, phosphoric acid, succinic acid, sulfuric acid, or pyrophosphoric acid. For example, when the metal is nickel, the plating solution S can be an aqueous solution of nickel nitrate, nickel phosphate, nickel succinate, nickel sulfate, nickel pyrophosphate, or nickel sulfamate. When the metal is copper, the plating solution S can be an aqueous solution containing copper sulfate, copper pyrophosphate, or the like.

[0026] The film forming apparatus 1 also includes a support frame 18. The support frame 18 supports the electrolyte membrane 13 and the substrate 12 from the side opposite the anode 11, with the electrolyte membrane 13 and the substrate 12 being arranged in contact with each other, and is detachably arranged in the liquid storage chamber 14. As shown in Fig. 2, the support frame 18 has a square frame-shaped first frame 181 that contacts and supports peripheral portions of the electrolyte membrane 13 and the substrate 12, and a second frame 182 that stands up from the first frame 181 and follows the side end portion 142 of the liquid storage chamber 14.

[0027] The area enclosed by the first frame 181 is larger than the area of ​​the mounting surface 151 (described later) of the mounting table 15 so as not to interfere with the overlapping of the lower surface of the base material 12 and the mounting surface 151 (see FIG. 1). The second frame 182 is removably fixed to the outer wall of the side end portion 142 of the liquid containing chamber 14 by, for example, screwing. 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 base material 12.

[0028] The mounting table 15 is made of a conductive material, and is disposed below the liquid storage chamber 14 so as to face the substrate 12 attached to the liquid storage chamber 14. The mounting table 15 has a mounting surface 151 that can be superimposed on the lower surface of the substrate 12. The mounting table 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 storage chamber moving device 24 that moves the liquid storage chamber 14 so that the substrate 12 attached below the liquid storage chamber 14 approaches the mounting table 15 so as to be superimposed on the mounting surface 151, and the substrate 12 is moved away from the mounting surface 151.

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

[0031] In this embodiment, the liquid storage chamber 14 is formed to be rotatable so that the electrolyte membrane 13 faces upward and downward. Specifically, a pair of side ends 142 of the liquid storage chamber 14 are fixed with a support shaft 144. The liquid storage chamber 14 is rotated by the drive of the rotation mechanism 25 while being rotatably supported on a support base (not shown) via the support shaft 144.

[0032] The configuration of the rotation 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 downward. In this embodiment, the rotation mechanism 25 is configured to include a motor 251 and an endless belt 252 stretched between the rotation shaft of the motor 251 and the support shaft 144.

[0033] Hereinafter, a film formation method using the film formation apparatus 1 of this embodiment will be described with reference to FIGS.

[0034] As shown in FIG. 3(a), the substrate 12 on which a film is to be formed is attached to the liquid storage chamber 14. Specifically, the liquid storage chamber 14 is first placed in a state in which the electrolyte membrane 13 with the opening 143 blocked faces upward. Next, the substrate 12 is placed on the electrolyte membrane 13 so as to be in contact with the electrolyte membrane 13. Next, the support frame 18 is fitted into the liquid storage chamber 14 so as to cover the substrate 12, and then the second frame 182 of the support frame 18 is fixed to the side end 142 of the liquid storage chamber 14 by screws. As a result, the electrolyte membrane 13 and the substrate 12, which are placed in contact with each other, are attached to the liquid storage chamber 14 via the support frame 18.

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

[0036] Next, the liquid storage chamber 14 is lowered using the storage chamber moving device 24 so that the lower surface of the substrate 12 is superposed on the mounting surface 151 of the mounting table 15 (see FIG. 4(a)). Then, after the lower surface of the substrate 12 is superposed on the mounting surface 151 of the mounting table 15, voltage application is started. That is, a voltage is applied between the anode 11 and the substrate 12, which is the cathode, using the power supply unit 16.

[0037] When a voltage is applied, metal derived from metal ions is precipitated on the surface of the substrate 12, which is the cathode, 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 Fig. 4(b), during film formation (in other words, when a voltage is applied), oxygen gas generated at the anode 11 passes through gaps inside the electrolyte membrane 13 due to buoyancy and collects at the ceiling of the liquid storage chamber 14.

[0038] When a metal film having a desired thickness is formed, the voltage application is terminated.

[0039] Next, without discharging the plating solution S from the liquid containing chamber 14, the containing chamber moving device 24 raises the liquid containing chamber 14 so as to separate the substrate 12 from the mounting table 15. When the liquid containing chamber 14 has been raised to a predetermined height, the liquid containing chamber 14 is rotated by the rotation mechanism 25 so that the electrolyte membrane 13 faces upward (see FIG. 5(a)).

[0040] Next, the substrate 12 is replaced. Specifically, as shown in FIG. 5(b), the support frame 18 is removed from the liquid storage chamber 14, and then the substrate 12 on which the film has been formed is removed from the electrolyte membrane 13. Then, as shown in FIG. 3(a) above, the substrate 12 on which the film is to be formed next is placed on the electrolyte membrane 13 and fixed by the support frame 18. When forming a film on both sides of the substrate 12, the surface on which the film has been formed is turned over so that the surface on which the film is to be formed is in contact with the substrate 12, and the substrate 12 is placed on the electrolyte membrane 13. Thereafter, the steps shown in FIG. 3(b) to FIG. 5(b) above may be repeatedly performed.

[0041] In the film forming apparatus 1 of this embodiment, the liquid containing chamber 14 is formed to be rotatable so that the electrolyte membrane 13 faces upward and downward. For example, when replacing the substrate 12, the liquid containing chamber 14 is rotated to place the electrolyte membrane 13 in the liquid containing chamber 14 facing upward, and the substrate 12 is replaced in this state, thereby reducing the load on the electrolyte membrane 13 due to the weight of the plating solution S, and preventing the electrolyte membrane 13 from stretching (also called bending) due to the load, damage to the electrolyte membrane 13, etc. Therefore, leakage of the plating solution S due to an abnormality such as damage to the electrolyte membrane 13 can be prevented.

[0042] Furthermore, by rotating the liquid storage chamber 14 during film formation so that the electrolyte membrane 13 faces downward, and forming a film on the substrate 12 in this state, the weight of the plating solution S can be used to press the substrate 12 against the mounting table 15. This makes it possible to prevent film formation defects and ensure the quality of the film formation. Furthermore, compared to the conventional case where a supply piston and a discharge piston are provided, it is only necessary to provide a rotation mechanism 25 for rotating the liquid storage chamber 14, and the structure of the device is simplified. 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] In addition, since the anode 11 is formed in a mesh shape or in a plate shape having a plurality of through holes, oxygen gas generated in the anode 11 when a voltage is applied can escape through the gaps within the anode 11, thereby suppressing the retention of oxygen gas on the surface of the electrolyte membrane 13 and preventing poor film formation due to the retention of oxygen gas.

[0044] Furthermore, the film forming apparatus 1 further includes a support frame 18 that supports the electrolyte membrane 13 and the substrate 12 from the side opposite the anode 11 with respect to the electrolyte membrane 13 and the substrate 12 arranged in contact with each other, and is detachable from the liquid storage chamber 14. This makes it possible to attach the electrolyte membrane 13 and the substrate 12 arranged in contact with each other to the liquid storage chamber 14 with the support frame 18, thereby preventing the electrolyte membrane 13 and the substrate 12 from detaching or falling when the liquid storage chamber 14 rotates, and preventing the electrolyte membrane 13 and the substrate 12 from detaching or falling when the electrolyte membrane 13 faces downward.

[0045] Although the embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment, and various design modifications can be made without departing from the spirit of the present invention described in the claims. For example, instead of the support frame 18, a jig capable of clamping the peripheral portions of the electrolyte membrane 13 and the substrate 12 may be used. [Explanation of symbols]

[0046] 1: film forming device, 11: anode, 12: substrate, 13: electrolyte membrane, 14: liquid storage chamber, 14a: supply flow path, 14b: discharge flow path, 15: mounting table, 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: storage chamber moving device, 25: rotation 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 formation device including an anode, an electrolyte membrane disposed between the anode and a substrate serving as a cathode, a liquid containing chamber that contains the anode and a plating solution and has an opening that is blocked by the electrolyte membrane, and a power supply unit that applies a voltage between the anode and the substrate, the film formation device forming a metal coating derived from metal ions in the plating solution on a surface of the substrate by applying a voltage with the electrolyte membrane in contact with the substrate, A film forming apparatus, wherein the liquid containing chamber is formed to be rotatable so that the electrolyte membrane faces upward and downward.

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

3. 3. The film forming apparatus according to claim 1, further comprising a support frame that supports the electrolyte membrane and the substrate from the opposite side of the anode, the electrolyte membrane and the substrate being arranged in contact with each other, and that is detachable from the liquid storage chamber.

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