Metal film deposition apparatus

Abstract

To provide a metallic film deposition apparatus that can remove a gas attached on an anode during deposition.SOLUTION: A deposition apparatus 1 for depositing a metallic film F on a substrate B contacting a polymer electrolyte 13 by electrolytic plating, comprises: an anode 11; a container 15 for accommodating the anode 11 and a plating solution L; and a polymer electrolyte 13 arranged at the opposite position of the anode 11 for covering an opening 15d of the container 15. The anode 11 has multiple penetrating parts 11c. A movable brush member 12 is arranged on an underside surface 11b among the surfaces of the anode 11 so as to contact the underside surface 11b that is positioned on the opposite side of an opposite surface 11a facing the polymer electrolyte 13.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a film forming apparatus for forming a metal film by electrolytic plating using an electrolyte membrane.

Background Art

[0002] Conventionally, as this type of film forming apparatus, a film forming apparatus has been proposed in which an anode and a plating solution are accommodated in a container, and an opening of the container formed at a position facing the anode is covered with an electrolyte membrane (see, for example, Patent Document 1). When forming a metal film on a substrate using this film forming apparatus, a voltage is applied to the anode and the surface of the substrate while the substrate is in contact with the electrolyte membrane. As a result, metal ions contained in the plating solution pass through the electrolyte membrane, are reduced on the surface of the substrate, and metal is deposited, forming a metal film. During film formation, water and the like contained in the plating solution are decomposed, and gas is generated on the surface of the anode. Therefore, the film forming apparatus is provided with a vibrating portion for vibrating the anode.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the technique of Patent Document 1, due to the vibration energy of the vibrating portion and the buoyancy in the plating solution, the gas generated on the surface of the anode can be detached from the surface of the anode. However, when the gas is fine or depending on the location where it adheres to the anode, it is difficult to remove the gas from the anode. In particular, when gas remains in the container, since gas is a compressible fluid, it is difficult to stably form a metal film while pressurizing the plating solution to a desired pressure.

[0005] The present invention has been made in view of these points, and its objective is to provide a metal film deposition apparatus that can remove gas adhering to the anode during film deposition. [Means for solving the problem]

[0006] In view of the above problems, the metal film deposition apparatus according to the present invention comprises an anode, a container for containing a plating solution together with the anode, and an electrolyte membrane covering an opening in the container formed at a position opposite to the anode, wherein a metal film is deposited on a substrate in contact with the electrolyte membrane by electroplating, wherein the anode is an anode with a plurality of through-holes formed thereon, and a movable brush member that contacts the back surface is arranged on the back surface of the anode, which is located on the side opposite to the surface facing the electrolyte membrane. [Effects of the Invention]

[0007] According to the present invention, by moving a movable brush member while keeping it in contact with the anode, gas adhering to the anode can be removed. [Brief explanation of the drawing]

[0008] [Figure 1] (a) is a schematic diagram of a metal film deposition apparatus according to this embodiment, and (b) is a schematic diagram for explaining the removal of gas adhering to the anode of the deposition apparatus shown in (a). [Figure 2] (a) is a schematic diagram of a metal film deposition apparatus according to a modified example, and (b) is a schematic diagram for explaining the removal of gas adhering to the anode of the deposition apparatus shown in (a). [Modes for carrying out the invention]

[0009] As shown in Figures 1(a) and (b), the film deposition apparatus 1 is a film deposition apparatus that deposits a metal film F on a substrate B by electroplating. The film deposition apparatus 1 comprises an anode 11, an electrolyte membrane 13, and a power supply 14 that applies a voltage between the anode 11 and the substrate B. The film deposition apparatus 1 further comprises a container 15 that houses the anode 11 and the plating solution L, a mounting table 40 on which the substrate B is placed, and a pressurizing device 60 that pressurizes the plating solution L in the container 15.

[0010] The film deposition apparatus 1 is equipped with a linear actuator 70 for raising and lowering the housing 15. The linear actuator 70 is provided with a linear rod 72 that moves in line with the main body 71. By moving the linear rod 72, which is attached to the tip of the housing 15, in the vertical direction relative to the main body 71, the housing 15 can be raised and lowered.

[0011] Substrate B functions as the cathode. Substrate B is a plate-shaped substrate. Of the surfaces of substrate B, the surface facing the electrolyte film 13 is the film-forming surface that functions as the cathode. Plating solution L is a liquid containing the metal of the metal film F to be formed in an ionic state. An example of such metal is copper. Plating solution L is a solution obtained by dissolving (ionizing) these metals with sulfuric acid or the like.

[0012] In this embodiment, the anode 11 is an insoluble anode that does not dissolve in the plating solution L. The anode material can be titanium, a titanium alloy, or platinum. If the anode material is titanium or a titanium alloy, its surface may be coated with iridium oxide or platinum. These coatings promote the reduction reaction of water, making it easier for metal to precipitate on the surface of the substrate B, while at the same time, they facilitate the generation of oxygen gas (gas) at the anode 11 through the electrolysis of water. The anode 11 has a plurality of through-holes 11c that penetrate in the thickness direction. However, the anode 11 may be a cage filled with insoluble metal balls. In this case, the through-holes are formed between the metal balls.

[0013] The housing 15 is made of a material that is insoluble in the plating solution L. The housing 15 has a housing space 15a for housing the plating solution L. The anode 11 is placed in the housing space 15a of the housing 15 via a support member 18. An opening 15d is formed on the substrate B side (lower side) of the housing space 15a. With the opening 15d covered by the electrolyte membrane 13, the electrolyte membrane 13 is fixed to the housing 15 by a frame 17.

[0014] The housing 15 has a supply port 15b and a discharge port 15c located on either side of the anode 11 in the housing space 15a, for supplying the plating solution L to or discharging it from the housing space 15a. The film deposition apparatus 1 further comprises a tank 90, a pump 80, and an on-off valve 54. As shown in Figure 1, the tank 90 contains the plating solution L. By opening and closing the on-off valve 54, the pump 80 can circulate the plating solution L from the tank 90 into the circulation path 50, thereby changing the plating solution L in the housing space 15a.

[0015] Furthermore, a pressurizing device 60 is connected to the housing 15 to pressurize the plating solution L in the housing space 15a during film formation. By discharging the plating solution L from the cylinder 61 of the pressurizing device 60 with a piston 62, the plating solution L in the housing space 15a can be pressurized.

[0016] In this embodiment, a movable brush member 12 is positioned on the back surface 11b of the anode 11, opposite to the facing surface 11a that faces the electrolyte membrane 13. The brush member 12 is a member in which a brush portion 12b is attached to a flat plate-shaped support 12a, and the tip of the brush portion 12b is in contact with the back surface 11b of the anode 11. The support 12a is attached to a drive device such as a motor 19 via a rotary-to-linear motion conversion mechanism (not shown). By driving the motor 19, the brush portion 12b reciprocates along the back surface 11b of the anode 11. The brush member 12 is preferably made of an insulating material that is resistant to the plating solution L.

[0017] According to this embodiment, as shown in Figure 1(b), the electrolytic film 13 is pressurized on the substrate B while the plating solution L is pressurized by the pressurizing device 60, and a voltage is applied between the anode 11 and the substrate B by the power supply 14. As a result, a metal film F is formed on the substrate B. At this time, gas G is generated by electrolysis on the opposing surface 11a of the anode 11, and the generated gas G passes through the penetration portion 11c of the anode 11 and adheres to the back surface 11b of the anode 11.

[0018] In this embodiment, for example, after film formation, the motor 19 is driven to reciprocate the brush member 12, thereby physically removing the gas G adhering to the anode 11 with the brush portion 12b. The removed gas G rises due to buoyancy and moves along the upper wall surface 15f, which is inclined upward toward the discharge port 15c.

[0019] When the plating solution L in the containment space 15a is replaced by driving the pump 80, any remaining gas G in the containment space 15a is also sent to the discharge port 15c by the flow of the plating solution L. The gas G discharged from the discharge port 15c is then discharged into the tank 90. ​​By discharging the gas G in the containment space 15a in this way, the metal film F can be formed during the next film formation while maintaining stable pressurization of the plating solution L by the pressurizing device 60. Alternatively, the gas generated on the opposing surface 11a of the anode 11 may be moved to the penetration portion 11c by vibration caused by moving the brush member 12.

[0020] Furthermore, in the modified versions shown in Figures 2(a) and (b), the structure of the brush member 12A is different. In these modified versions, the brush member 12A is a rotating member that rotates due to the flow of the plating solution L. The brush member 12A is equipped with a fan 12c that rotates due to the flow of the plating solution L, and a plurality of blades 12d attached to the outer circumference of the fan 12c. The blades 12d are flexible, and their tips are in contact with the back surface 11b of the anode 11.

[0021] In this modification example, when the plating liquid L in the accommodation space 15a is replaced by driving the pump 80, each brush member 12A rotates due to the liquid flow of the plating liquid L, and the gas G attached to the anode 11 can be physically removed by the blade 12d. The removed gas G rises due to buoyancy, flows together with the plating liquid L toward the discharge port 15c, and is discharged from the discharge port 15c to the tank 90. Also in this modification example, by discharging the gas G in the accommodation space 15a, at the time of the next film formation, the metal film F can be formed in a state where the pressurization of the plating liquid L by the pressurizing device 60 is stabilized.

[0022] In the present embodiment, the gas attached to the anode is removed by the brush member. However, for example, the anode together with the support member may be lifted to a space filled with gas in the accommodation space by using a spring or buoyancy, and then the gas may be removed by immersing the anode in the plating liquid again. In addition to this, the gas attached to the anode may be removed by spraying the plating liquid from a nozzle disposed in the accommodation space onto the back surface of the anode, or by directly spraying the plating liquid supplied from the supply port onto the back surface of the anode to remove the gas attached to the anode. In addition to this, the gas attached to the anode may be removed by moving the anode together with the support member.

Description of Reference Numerals

[0023] 1: Film forming apparatus for metal film, 11: Anode, 11a: Opposing surface, 11b: Back surface, 11c: Through hole, 12: Brush member, 13: Electrolyte membrane, 15: Container, 15d: Opening, F: Metal film, L: Plating liquid

Claims

[Claim 1] A metal film forming apparatus comprising an anode, a container for containing a plating solution together with the anode, and an electrolyte membrane covering an opening in the container formed at a position opposite the anode, wherein a metal film is formed on a substrate in contact with the electrolyte membrane by electroplating, The anode is an anode in which multiple through-holes are formed, A metal film deposition apparatus characterized in that a movable brush member is arranged on the back surface of the anode, which is located on the side opposite to the surface facing the electrolyte membrane, and which contacts the back surface.

Images