JP2023090542A - Metal film forming apparatus and method of film formation - Google Patents

Abstract

To provide a film forming apparatus with which after a metal film is formed, an electrolyte film can be easily separated from a base material while suppressing the elongation of the electrolyte film.SOLUTION: A control device 60 of a film forming apparatus 1 controls a lifting operation by a lifting device 70 so that a base material W is in contact with an electrolyte film 13, and concurrently controls a suction operation by a suction pump 52. Then, the control device 60 controls an application operation by a power supply part 19 until a metal film F has a prescribed film thickness after the base material W is in contact with the electrolyte film 13, and after the completion of the application operation, controls the lifting operation by the lifting device 70 so that the base material W is separated from the electrolyte film 13, and concurrently controls a pressure-feeding operation by an air pump 51.SELECTED DRAWING: Figure 1

Description

The present invention relates to a film forming apparatus and a film forming method for forming a metal film on the surface of a substrate.

As a technique of this kind, for example, Patent Literature 1 proposes a film forming apparatus for forming a metal film on the surface of a base material. This film forming apparatus includes an anode, an electrolyte membrane arranged between the anode and a base material serving as a cathode, and a power supply section for applying a voltage between the anode and the base material. In the film forming apparatus, between the anode and the electrolyte membrane, there is a container that accommodates the plating solution so as to be in contact with them. and a suction device for suction. According to this film forming apparatus, by providing the suction device, it is possible to form the metal film while suppressing entrainment of air between the electrolyte film and the substrate.

Japanese Unexamined Patent Application Publication No. 2014-051701

However, when the electrolyte film is separated from the base material after forming the metal film with the film forming apparatus described in Patent Document 1, the electrolyte film may adhere to the metal film. It can be stretched.

The present invention has been made in view of these points, and its object is to easily separate the electrolyte membrane from the substrate while suppressing the stretching of the electrolyte membrane after the formation of the metal coating. It is an object of the present invention to provide a film forming apparatus capable of

In view of the above problems, a metal film deposition apparatus according to the present invention contains an anode, an electrolyte film disposed between the anode and a substrate, the anode and a plating solution, and and a power supply section for applying a voltage between the anode and the base material serving as a cathode, wherein the electrolyte membrane is brought into contact with the base material. a film forming apparatus for forming a metal film derived from the metal ions of the plating solution on the surface of the base material by applying the voltage, the film forming apparatus having the base material placed thereon. a lifting device for lifting and lowering at least one of the container and the mounting table so that the electrolyte membrane can be brought into contact with and separated from the substrate; and the substrate mounted on the mounting table. a suction device for sucking air existing between the material and the electrolyte membrane; a pumping device for pumping air between the substrate placed on the mounting table and the electrolyte membrane; a control device for controlling an up-and-down operation by the apparatus, a suction operation by the suction device, an application operation by the power supply unit, and a pumping operation by the pumping device, wherein the controller controls the base material to be the electrolyte While controlling the lifting operation by the lifting device so as to contact the membrane, the suction operation by the suction device is controlled, and after the base material contacts the electrolyte membrane, until the metal film reaches a predetermined thickness. and controlling the application operation by the power supply unit, and controlling the lifting operation by the lifting device so that the base material is separated from the electrolyte membrane after the completion of the application operation, while controlling the pumping operation by the pumping device. It is characterized by

According to the present invention, first, the suction device controls the suction operation while controlling the lifting operation of the lifting device so that the base material comes into contact with the electrolyte membrane. By this control, the electrolyte membrane is brought into contact with the substrate while sucking the air between the electrolyte membrane covering the opening formed in the container and the substrate arranged facing the electrolyte membrane with the suction device. can be made As a result, entrainment of air between the electrolyte membrane and the substrate can be suppressed, and the electrolyte membrane can be brought into close contact with the substrate.

Next, the control device controls the voltage application operation by the power supply unit until the metal coating reaches a predetermined thickness after the base material contacts the electrolyte membrane. With this control, when a voltage is applied between the anode and the substrate while the electrolyte membrane is in contact with the substrate, the metal ions move to the surface side of the substrate via the electrolyte membrane, and the substrate At the surface, it can be reduced to deposit metal. As a result, a metal film derived from the deposited metal can be formed on the surface of the substrate. By applying such a voltage until the metal film reaches a predetermined film thickness, a metal film having a desired film thickness can be formed.

Finally, after the application operation is completed (that is, after the voltage application for film formation is completed), the control device controls the lifting operation by the lifting device so that the electrolyte film is separated from the substrate, and the pumping device controls the pumping operation. As a result, the electrolyte membrane can be separated from the substrate while supplying air between the substrate on which the metal film is formed and the electrolyte membrane, so that the electrolyte membrane is adsorbed to the substrate and stretched. It is possible to easily separate the electrolyte membrane from the substrate while suppressing the In particular, when the electrolyte membrane is in contact with the base material in the closed space, the closed space becomes a space depressurized by the suction device. can be increased, and the adsorption between the electrolyte membrane and the substrate can be suppressed.

As a more preferable aspect, the film forming apparatus further includes a replacement mechanism for replacing the plating solution accommodated in the container with the atmosphere, and the control device controls the operation of the plating solution after the power supply unit completes the application operation. The exchange mechanism is controlled so that the plating solution is exchanged with the atmosphere before starting control of the lifting operation by the lifting device so that the electrolyte film is separated from the substrate.

According to this aspect, the control device controls the replacement mechanism so that the plating solution is replaced with the atmosphere before starting the control of the lifting operation. With this control, the electrolyte membrane is separated from the base material after the plating solution contained in the container is replaced with the atmosphere while the electrolyte membrane is in contact with the base material, so that the electrolyte membrane is deformed by its own weight. can refrain from doing Furthermore, since the weight of the plating solution does not act on the electrolyte membrane, it becomes easier for air to enter between the electrolyte membrane and the substrate, making it easier to separate the electrolyte membrane from the substrate. Here, of the "air" referred to in this specification, the sucked air is the air existing between the electrolyte membrane and the substrate, and the pumped air is the air in the atmosphere. It is pressurized. The "atmosphere" for exchanging the plating solution contained in the containing body means atmospheric pressure air in the atmosphere.

In this specification, a method for forming a metal film is also disclosed as the present invention. In the method for forming a metal film according to the present invention, a voltage is applied between an anode and a substrate serving as a cathode while an electrolyte film in contact with a plating solution containing metal ions is in contact with the substrate, A film forming method for forming a metal film derived from metal ions contained in an electrolyte film on the surface of the substrate, comprising: the electrolyte film covering an opening formed in a container; a step of contacting the electrolyte membrane with the base material while sucking air existing between the base material and the base material arranged facing each other; a step of applying a voltage between the anode and the base material to form the metal coating until the coating reaches a predetermined thickness; the base on which the metal coating is formed; and the electrolyte. and separating the electrolyte membrane from the substrate while pumping air between the electrolyte membrane and the membrane.

According to the present invention, first, in a state in which the plating solution is stored in the container, the air between the electrolyte membrane covering the opening formed in the container and the base material arranged facing the electrolyte membrane is removed. is sucked by a suction device, the electrolyte membrane is brought into contact with the substrate. As a result, entrainment of air between the electrolyte membrane and the substrate can be suppressed, and the electrolyte membrane can be brought into close contact with the substrate.

Next, when a voltage is applied between the anode and the substrate while the electrolyte membrane is in contact with the substrate, the metal ions migrate to the surface side of the substrate through the electrolyte membrane, and the surface of the substrate , can be reduced and the metal can be deposited. As a result, a metal film derived from the deposited metal can be formed on the surface of the substrate. By applying such a voltage until the metal film reaches a predetermined film thickness, a metal film having a desired film thickness can be formed.

Finally, the electrolyte membrane can be pulled away from the substrate while supplying air between the substrate on which the metal film is formed and the electrolyte membrane, so that the electrolyte membrane is adsorbed to the substrate and stretched. It is possible to easily separate the electrolyte membrane from the substrate while suppressing the In particular, when the electrolyte membrane is in contact with the base material in the closed space, the closed space becomes a space depressurized by the suction device. can be increased, and the adsorption between the electrolyte membrane and the substrate can be suppressed.

A more preferable film forming method further includes a step of exchanging the plating solution contained in the containing body with air after the step of forming the metal film and before the separating step.

According to this aspect, after the plating solution contained in the container is replaced with the atmosphere while the electrolyte membrane is in contact with the base material, the electrolyte membrane is separated from the base material. deformation can be suppressed. Furthermore, since the weight of the plating solution does not act on the electrolyte membrane, it becomes easier for air to enter between the electrolyte membrane and the substrate, making it easier to separate the electrolyte membrane from the substrate.

According to the present invention, it is possible to easily separate the electrolyte membrane from the substrate while preventing the electrolyte membrane from being stretched after forming the metal coating.

1 is a schematic cross-sectional view of a metal film deposition apparatus according to an embodiment of the present invention; FIG. 2 is a flowchart for explaining control of the film forming apparatus shown in FIG. 1; 1. It is sectional drawing for demonstrating the attraction|suction / contact process shown in FIG. 2 using the film-forming apparatus shown in FIG. 3 is a cross-sectional view for explaining the film forming process shown in FIG. 2 using the film forming apparatus shown in FIG. 1; FIG. 1. It is sectional drawing for demonstrating the replacement process shown in FIG. 2 using the film-forming apparatus shown in FIG. 3 is a cross-sectional view for explaining the pumping/separation step shown in FIG. 2 using the film forming apparatus shown in FIG. 1; FIG. FIG. 4 is a diagram illustrating the relationship between the elongation rate of an electrolyte film and the number of film formations using the film formation apparatuses of Examples and Comparative Examples.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A metal film forming apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the film forming apparatus 1 accommodates an anode 11, an electrolyte membrane 13 arranged between the anode 11 and the substrate W, the anode 11 and the plating solution L, and and a housing body 15 in which the opened opening 15 g is covered with the electrolyte membrane 13 . The film forming apparatus 1 includes a power supply unit 19 that applies a voltage between the anode 11 and the base material W serving as a cathode, a mounting table 20 on which the base material W is placed, and an elevating device 70 that elevates the container 15 . , is further provided.

In the film forming apparatus 1 , the substrate W placed on the mounting table 20 is brought into contact with the electrolyte film 13 by the lifting device 70 , and the power supply unit 19 operates between the anode 11 and the substrate W. A voltage is applied to form a metal film on the surface wa of the substrate W. As shown in FIG. At the time of film formation, the metal ions contained in the electrolyte film 13 from the plating solution L are reduced on the surface wa of the base material W, the metal derived from the metal ions is deposited, and the deposited metal forms the metal film F. film (see, for example, FIG. 5).

The substrate W functions as a cathode. The material of the base material W is not particularly limited as long as it functions as a cathode (that is, a surface having conductivity), and may be made of a metal material such as aluminum or iron, or may be made of resin, ceramics, or the like. The surface may be coated with a metal layer such as copper, nickel, silver, or iron.

The mounting table 20 is made of a conductive material and is arranged below the container 15 so that the base material W faces the electrolyte membrane 13 . A base material (specifically, a cathode) W is electrically connected to the negative electrode of the power source section 19 via the mounting table 20 . When the mounting table 20 is made of an insulating material, the negative electrode of the power source section 19 may be directly connected to the base material W via wiring.

As will be described later, the mounting table 20 is connected to an air pump (pumping device) 51 via a pressure feeding path 81 and to a suction pump (suction device) 52 via a suction path 82 . The air pump 51 is a device for pumping pressurized air between the substrate W placed on the mounting table 20 and the electrolyte membrane 13 , and the suction pump 52 is placed on the mounting table 20 . It is a device for sucking the air existing between the base material W and the electrolyte membrane 13 . The details of the suction mechanism and the pumping mechanism including the mounting table 20 will be described later.

The anode 11 is attached to a later-described container 15 so as to face the mounting table 20 (specifically, the base material W), and is electrically connected to the positive electrode of the power supply unit 19 via a lead wire or the like. ing. The anode 11 has a shape corresponding to the film-forming region of the substrate W. As shown in FIG. The film-forming region of the base material W is the surface of the surface wa of the base material W that faces the anode 11 and that functions as a cathode. Anode 11 is a non-porous (for example, non-porous) anode made of the same metal as the metal of the metal film, and is a block-shaped or plate-shaped anode. The anode 11 is made of the same metal as the metal film, and may be soluble or insoluble in the plating solution L. However, the anode may also be a porous, mesh, or metal ball lined container, provided that the required surface area is met.

When the anode 11 is soluble in the plating solution L, examples of its material include copper, nickel, silver, and tin. In the present embodiment, there is no particular limitation as long as the anode 11 is dissolved by applying a voltage using the power supply section 19 . When the anode 11 is insoluble in the plating solution L, stainless steel, titanium, titanium alloys, and the like can be used.

The plating solution (electrolytic solution) L is a solution containing the metal of the metal film to be formed as described above in the form of ions. Examples of the metal include copper, nickel, silver, and tin. be able to. The plating solution L is an aqueous solution obtained by dissolving (ionizing) these metals with an acid such as nitric acid, phosphoric acid, succinic acid, sulfuric acid, or pyrophosphoric acid. For example, when the metal is nickel, examples of the plating solution L include aqueous solutions of nickel nitrate, nickel phosphate, nickel succinate, nickel sulfate, nickel pyrophosphate, nickel sulfamate, and the like. For example, when the metal is copper, the plating solution L may be an aqueous solution containing copper sulfate, copper pyrophosphate, or the like.

The electrolyte membrane (solid electrolyte membrane) 13 is a flexible membrane that can be impregnated (contained) with metal ions when brought into contact with the plating solution L described above. The electrolyte membrane 13 is not particularly limited as long as the metal ions are reduced in the substrate W when a voltage is applied by the power supply unit 19 and the metal derived from the metal ions can be deposited. The material of the electrolyte membrane 13 is, for example, fluorine-based resin such as Nafion (registered trademark) manufactured by DuPont, hydrocarbon-based resin, polyamic acid resin, or ion such as Selemion (CMV, CMD, CMF series) manufactured by Asahi Glass Co., Ltd. A resin having an exchange function can be mentioned.

As shown in FIG. 1, the housing body 15 is made of a material insoluble in the plating solution L, and the anode 11 and the electrolyte membrane 13 are attached to the housing body 15 . In this embodiment, a storage space S for storing the plating solution L is formed inside the container 15 by the side wall of the container 15 , the anode 11 and the electrolyte membrane 13 . An anode 11 is attached to the inner surface of the container 15 , and an opening 15 g that opens toward the base material W is formed at a position facing the anode 11 . The opening 15g opens downward, and the electrolyte membrane 13 is attached so as to seal the opening 15g. In this embodiment, the periphery of the electrolyte membrane 13 is attached to the container 15 by being sandwiched between the main body 15a and the frame 15b of the container 15 . The anode 11 and the electrolyte membrane 13 are arranged apart from each other and are in a non-contact state, and a storage space S formed between them is filled with the plating solution L during film formation. Thus, the container 15 has a structure in which the plating solution L contained in the container space S directly contacts the anode 11 and the electrolyte membrane 13 .

A supply channel 15c for supplying the plating solution L to the accommodation space S and a discharge channel 15d for discharging the plating solution L from the accommodation space S are formed in the container 15 . The supply channel 15c and the discharge channel 15d communicate with the accommodation space S. Both the supply channel 15 c and the discharge channel 15 d communicate with the housing space S in the vicinity of the electrolyte membrane 13 .

The elevating device 70 is a device for elevating at least one of the container 15 and the mounting table 20 so that the electrolyte membrane 13 and the substrate W can be brought into contact with each other. In this embodiment, the mounting table 20 is fixed without moving, and the lifting device 70 lifts and lowers only the container 15 . Specifically, as shown in FIGS. 1 and 3, the lifting device 70 includes a device main body 71 and a rod 72 that moves linearly with respect to the device main body 71. The rod 72 moves along the container body. It is fixed to the top of 15. The lifting device 70 may be a known electric actuator that converts rotation of a motor such as a servomotor into linear motion. As long as the electrolyte membrane 13 can be brought into contact with and separated from the substrate W by linear motion, the lifting device 70 may be provided on the mounting table 20, or may be a hydraulic or pneumatic cylinder. good.

A circulation mechanism for circulating the plating solution L in the film forming apparatus 1, a suction mechanism and a pumping mechanism including the mounting table 20, and the control device 60 will be described below. The film forming apparatus 1 is connected to a container 15 as a circulation mechanism, and a tank 17 that stores the plating solution L discharged from the container 15 is connected to the tank 17 to circulate the plating solution L in the tank 17. and a pump 18 for pumping to the container.

An electric heating device 90 for heating the plating solution L is provided in the tank 17 . The heating method of the heating device 90 is not particularly limited as long as it can heat the plating solution L to a predetermined temperature. For example, a steam heater may be used. In this embodiment, the plating solution L stored in the tank 17 is heated by the heating device 90, and the heated plating solution L is supplied from the tank 17 to the storage space S of the container 15 by the pump 18. Therefore, the deposition rate of the metal film F can be increased. In this embodiment, the heating device is provided in the tank 17. However, if the plating solution L heated to a predetermined temperature can be used for film formation, the heating device can be installed in the container 15. It may be provided, or may be provided in the supply path 87 between the tank 17 and the container 15 . The term "path" used in the present embodiment refers to a flow path formed by piping and through which the plating solution L or atmospheric air (that is, atmospheric air) flows.

In this embodiment, the tank 17 is connected to the containing body 15 via the supply path 87 . A pump 18 is provided in the supply path 87, and the pump 18 is capable of forward rotation and reverse rotation. When the pump 18 rotates forward, it is possible to send the plating solution L from the tank 17 to the container 15, and when it rotates in the reverse direction, it is possible to send the plating solution L from the container 15 to the tank 17. becomes.

Discharge paths 83 and 84 for returning the plating solution L discharged from the container 15 to the tank 17 are connected to the container 15 . In this embodiment, a three-way valve 56 is provided between the discharge path 83 and the discharge path 84 . The three-way valve 56 is connected to an open path 85 open to the atmosphere in addition to the discharge paths 83 and 84 . The three-way valve 56 has a first switching position in which the discharge paths 83 and 84 are communicated, and a second switching position in which the discharge path 83 and the open path 85 are communicated. Each switching position by the three-way valve 56 is controlled by the controller 60 .

Here, as shown in FIG. 4, if the pump 18 is rotated forward and the three-way valve 56 is controlled to the first switching position, the plating solution L is supplied to the container 15 in the film forming apparatus 1. The plating solution L can be circulated while being filled. Specifically, the plating solution contained in the tank 17 is supplied to the containing body 15 through the supply path 87 by the pump 18, and the plating solution discharged from the containing body 15 flows through the discharge path 83 and the discharge path 84. is returned to the tank 17 via the

In this embodiment, for example, the discharge path 84 may be provided with a pressure regulating valve (not shown) for adjusting the liquid pressure of the plating solution L discharged from the container 15 . As a result, the liquid pressure of the plating solution L accommodated in the accommodation space of the container 15 can be adjusted to the pressure set by the pressure regulating valve.

On the other hand, as shown in FIG. 5, by rotating the pump 18 in the reverse direction and controlling the three-way valve 56 to the second switching position, the plating solution L contained in the container 15 can be replaced with the atmosphere. can. Specifically, when the three-way valve 56 is in the second switching position and the pump 18 is rotated in reverse, atmospheric air is sucked through the open path 85 and flows into the container 15 through the discharge path 83, The plating solution L contained in is returned to the tank 17 . As a result, the accommodation space S of the accommodation body 15 is filled with atmospheric pressure air (atmosphere).

In this embodiment, the three-way valve 56 , the open path 85 and the pump 18 constitute the replacement mechanism 50 . However, it is not limited to such an apparatus mechanism, and a replacement mechanism is a mechanism in which a liquid drain hole is provided near the bottom of the container 15 and the plating solution L is discharged by the weight of the plating solution L. may In addition, the replacement mechanism may be a mechanism that pumps air into the storage space S of the storage body 15 using an air pump 51 (to be described later) or another air pump. The configuration of the exchange mechanism is not particularly limited as long as the plating solution L can be exchanged with the air in the container 15 .

A recess 21 for accommodating the substrate W is formed in the mounting table 20 . In this embodiment, a gap is formed between the side wall of the recess 21 and the side surface of the substrate W. As shown in FIG. The mounting table 20 is a portion including a concave portion 21 so that the surface wa of the substrate W is in contact with the electrolyte membrane 13 and is inserted into the frame 15b of the container 15 and loosely fitted into the frame 15b. protrudes toward the container 15 side. As a result, the space including the substrate W and the electrolyte membrane 13 becomes a sealed space with the frame 15b loosely fitted on the mounting table 20 when the container 15 is moved up and down.

A flow path 22 is formed in the mounting table 20 , and the flow path 22 communicates with the sidewall of the recess 21 , the side surface of the substrate W, and the gap. An air pump 51 is connected to the flow path 22 . Specifically, the pressure-feeding path 81 is connected to the flow path 22, and the pressure-feeding path 81 is provided with an air pump 51 and an on-off valve 53 from the upstream side to the downstream side. As shown in FIG. 6 , when the air pump 51 is activated, the control device 60 opens the on-off valve 53 to supply compressed air to the flow path 22 via the pumping path 81 . The air supplied to the flow path 22 flows through the gap between the side wall of the recess 21 and the side surface of the base material W, and is pressure-fed between the base material W mounted on the mounting table 20 and the electrolyte membrane 13 . When the air pump 51 is driven, the on-off valve 55 provided in the flow path 22 may be closed by the control device 60 and the on-off valve 54 to be described later may be opened by the control device 60 .

In this embodiment, a suction pump 52 is connected to the channel 22 . Specifically, a suction path 82 different from the pumping path 81 is connected to the flow path 22 , and the suction path 82 is provided with an on-off valve 54 and a suction pump 52 from the upstream side to the downstream side. As shown in FIG. 6, the controller 60 opens the on-off valves 54 and 55 when the suction pump 52 is activated, and the air between the electrolyte membrane 13 and the base material W is released from the sidewall of the recess 21 and the base material. It flows through the gap with the side surface of W and is released to the atmosphere via the flow path 22 and the suction path 82 . In this manner, air between the electrolyte membrane 13 and the substrate W can be sucked by the suction pump 52 . Note that, when the air pump 51 is driven, the open/close valve 53 of the pumping path 81 may be closed by the control device 60 .

The control device 60 controls the lifting operation by the lifting device 70 , the suction operation by the suction pump 52 , the application operation by the power supply unit 19 , the switching operation by the switching mechanism 50 (specifically, the driving of the pump 18 and its rotation direction), and the air pump 51 . , and the operations of the on-off valves 53 to 55 and the three-way valve 56 are also controlled accordingly. Note that the application operation of the power supply unit 19 is the operation of a switch that applies a voltage from the power supply unit 19 .

Although not shown, the control device 60 includes a storage device (not shown) that stores a control program for executing the following series of steps, and an arithmetic device (not shown) that executes the control program. The storage device further stores set values such as start timing and drive time of the pump 18, air pump 51, and suction pump 52, application start time and application time of the power supply unit 19, and the amount of displacement by the lifting device 70. The controller 60 receives a signal from a pressure sensor (not shown) that measures the pressure in the housing space S of the housing 15 by an input device or the like.

A control flow of the control device 60 will be described with reference to FIG. 2 below. The control device 60 performs the following series of operations. First, the installation step S1 is performed. Specifically, in this step, the substrate W is placed on the mounting table 20 by controlling a conveying device (not shown) and the like. At this time, the alignment of the substrate W with respect to the anode 11 attached to the container 15 may be adjusted, and the temperature of the substrate W may be adjusted.

Next, the suction/contact step S2 is performed. Specifically, as shown in FIG. 3 , the control device 60 controls the lifting operation by the lifting device 70 so that the substrate W contacts the electrolyte membrane 13 , and also controls the suction operation by the suction pump 52 . By this control, the electrolyte membrane 13 is moved to the base material while sucking the air existing between the electrolyte membrane 13 covering the opening 15g of the container 15 and the base material W arranged facing the electrolyte membrane 13. Make contact with W. As a result, it is possible to prevent air from entering between the electrolyte membrane 13 and the substrate W, and to bring the electrolyte membrane 13 into close contact with the substrate W. In this state, the controller 60 stops the suction pump 52 . In this state, channel 22 is at a negative pressure (relative to atmospheric pressure). At this stage, the controller 60 closes the on-off valves 53 to 55 as necessary.

Next, liquid transfer step S3 is performed. In this step, the controller 60 controls the driving of the pump 18 and controls the three-way valve 56 to the first switching position. As a result, as shown in FIG. 4, by driving the pump 18 in forward rotation, the plating solution L heated to a predetermined temperature by the heating device 90 is supplied from the supply path 87 to the container 15 in the tank 17. It can be supplied to the accommodation space S and returned to the tank 17 via the discharge paths 83 , 84 .

Here, if the liquid pressure of the plating solution L accommodated in the accommodation space S can be maintained at a predetermined pressure by the above-described pressure regulating valve, the control device 60 will operate the pump 18 even during film formation. It may be driven continuously. Further, an on-off valve (not shown) may be provided in the discharge path 83 and the control device 60 may close the on-off valve to stop the pump 18 when a predetermined pressure is maintained.

Next, film-forming process S4 is performed. In this step, the control device 60 controls the voltage application operation by the power source section 19 until the metal film F reaches a predetermined thickness after the substrate W contacts the electrolyte membrane 13 . Specifically, when a voltage is applied between the anode 11 and the base material W while the electrolyte membrane 13 is in contact with the base material W, metal ions are transferred to the surface side of the base material W through the electrolyte membrane 13. , and is reduced on the surface wa of the base material W, the metal is deposited, and a metal film F is formed. By applying such a voltage until the metal film F reaches a predetermined film thickness, the metal film F having a desired film thickness can be formed.

Next, the replacement step S5 is performed. In this step, the controller 60 controls the replacement mechanism 50 (specifically, the pump 18 and the three-way valve 56) so that the plating solution L is replaced with the air. Specifically, the control device 60 switches the three-way valve 56 to the second switching position and reversely rotates the pump 18, so that the plating solution L in the storage space S of the storage body 15, as shown in FIG. It is returned to tank 17 via supply path 87 . At the same time, air is introduced into the open path 85 , and the introduced air is supplied to the accommodation space S of the container 15 via the discharge path 83 . When almost all of the plating solution L is discharged from the accommodation space S, the control device stops the pump 18 . Note that FIG. 5 shows a stage in the middle of replacing the plating solution L stored in the storage space with the air.

Next, the pumping/spacing step S6 is performed. Specifically, as shown in FIG. 6 , the controller 60 controls the pumping operation of the air pump 51 while controlling the lifting operation of the lifting device 70 so that the substrate W is separated from the electrolyte membrane 13 . By this control, the electrolyte membrane 13 is separated from the substrate W while air is pumped between the substrate W on which the metal film F is formed and the electrolyte membrane 13 . Specifically, the air pressure-fed by the air pump 51 flows through the channel 22 via the pressure-feeding path 81, is pushed between the electrolyte membrane 13 and the base material W, flows through the channel 22, and flows through the suction path. The suction pump 52 is discharged via 82 .

In the present embodiment, the control device 60 closes the on-off valve 55 and operates the suction pump 52 so that the channel 22 does not become negative pressure (preferably positive pressure) so that such a flow is formed. pressure). However, if air can flow between the electrolyte membrane 13 and the substrate W, the suction pump 52 is not driven, and the air discharged from the suction path 82 is transferred to the atmosphere on the upstream side of the suction pump 52. You can release it inside.

Finally, an extraction step S7 is performed. In this step, the base material W and the container 15 have the positional relationship shown in FIG. When forming a metal film on a new substrate W, a series of these steps are repeated.

According to the present embodiment, as described above, in the pumping/separating step S6, air is pumped between the electrolyte membrane 13 having the metal film F formed thereon and the base material W, and the electrolyte membrane 13 is moved to the base material. Separated from W. This makes it possible to easily separate the electrolyte membrane 13 from the base material W while preventing the electrolyte membrane 13 from being adsorbed to the base material W and being stretched. In particular, in the present embodiment, the electrolyte membrane 13 is in contact with the base material W in the sealed space, so the sealed space becomes a space decompressed by the suction pump 52 in the suction/contact step S2. By pumping air by the air pump 51 in the pumping/separating step S6, the pressure in the space can be increased, and adsorption between the electrolyte membrane 13 and the substrate W can be suppressed.

Furthermore, after the plating solution L stored in the storage body 15 is replaced with the atmosphere in the replacement step S5 while the electrolyte membrane 13 is in contact with the base material W, the electrolyte membrane 13 is separated from the base material W. Deformation of the film 13 due to the weight of the plating solution L can be suppressed. Furthermore, since the weight of the plating solution L does not act on the electrolyte membrane 13, it becomes easier for air to enter between the electrolyte membrane 13 and the base material W in the pumping/separation step S6, and the electrolyte membrane 13 is separated from the base material W. Easier to pull apart.

The invention is illustrated by the following examples.

[Example]
A copper block substrate having a film formation area of 18 mm×35 mm and a thickness of 3 mm was prepared as a substrate for forming a film on the surface.

Next, a nickel film was formed using the film forming apparatus shown in FIG. "1M nickel chloride + nickel acetate aqueous solution (pH 4.0)" was prepared as the plating solution, and a nickel anode was used as the anode. As film formation conditions, the temperature of the plating solution was set to 60° C., an electrolyte film (Nafion (registered trademark): manufactured by DuPont) was brought into close contact with the substrate, and the liquid pressure of the plating solution was 1.0 MPa, and the current density was 15 A/dm ² . , and energization was performed for 3 minutes and 20 seconds to form a nickel film. This was repeated multiple times according to the flow shown in FIG.

[Comparative example]
A nickel film was formed in the same manner as in the example. The difference from the embodiment is that the pumping/spacing step S6 shown in FIG. 2 was not performed.

<Confirmation of Elongation Rate of Electrolyte Membrane>
The elongation rate of the electrolyte film after repeated film formation was measured using the film formation apparatuses according to the examples and the comparative examples. The results are shown in FIG. FIG. 7 is a diagram for explaining the relationship between the elongation rate of the electrolyte film and the number of film formations using the film formation apparatuses of Examples and Comparative Examples.

As shown in FIG. 7, when a nickel film was formed using the film forming apparatus of the example, even if the number of film forming times exceeded 90, the electrolyte film was formed before film formation for the reason described above. It hardly stretched compared to the one of (1). However, as in the comparative example, the electrolyte membrane was plastically deformed and elongated by about 16% after several film formations without the pumping/separating process.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various designs can be made without departing from the spirit of the invention described in the claims. Changes can be made.

In the present embodiment, the film forming method is performed under the control of the control device, but for example, the series of operations shown in FIG. 2 may be performed manually without being controlled by the control device. can be done by

1: film forming apparatus, 11: anode, 13: electrolyte membrane, 15: container, 15g: opening, 17: tank, 19: power supply unit, 20: mounting table, 50: replacement mechanism, 51: air pump (pumping device ), 52: Suction pump (suction device), 60: Control device, 70: Lifting device, W: Base material, L: Plating solution

Claims (4)

an anode;
an electrolyte membrane disposed between the anode and a substrate;
a container containing the anode and the plating solution and having an opening facing the base material covered with the electrolyte membrane;
A power supply unit that applies a voltage between the anode and the base material that serves as a cathode,
A film forming apparatus for forming a metal film derived from metal ions of the plating solution on the surface of the base material by applying the voltage while the electrolyte film is in contact with the base material,
The film forming apparatus is
a mounting table for mounting the base material;
an elevating device for elevating at least one of the container and the mounting table so that the electrolyte membrane can be brought into contact with and separated from the base;
a suction device for sucking air existing between the base material placed on the mounting table and the electrolyte membrane;
a pumping device for pumping air between the substrate placed on the mounting table and the electrolyte membrane;
A control device that controls the lifting operation by the lifting device, the suction operation by the suction device, the application operation by the power supply unit, and the pumping operation by the pumping device,
The control device is
While controlling the lifting operation by the lifting device so that the base material contacts the electrolyte membrane, controlling the suction operation by the suction device;
After the base material comes into contact with the electrolyte membrane, the voltage application operation by the power supply unit is controlled until the metal coating reaches a predetermined thickness,
After the completion of the application operation, the pumping operation is controlled by the pumping unit while controlling the lifting operation by the lifting unit so that the electrolyte film is separated from the substrate. . The film forming apparatus further includes a replacement mechanism for replacing the plating solution contained in the container with the atmosphere,
The control device controls the lifting operation of the lifting device so that the electrolyte film is separated from the substrate after the application operation by the power source is completed, and the plating solution is replaced with the atmosphere. 2. The apparatus for depositing a metal film according to claim 1, wherein said replacement mechanism is controlled immediately. A metal film derived from the metal ions contained in the electrolyte film is formed by applying a voltage between the anode and the substrate, which is the cathode, while the electrolyte film in contact with the plating solution containing metal ions is in contact with the substrate. A film formation method for forming a film on the surface of the base material,
The electrolyte membrane is brought into contact with the base material while sucking the air present between the electrolyte membrane covering the opening formed in the container and the base material arranged facing the electrolyte membrane. and
a step of forming the metal film by applying a voltage between the anode and the substrate while the electrolyte film is in contact with the substrate until the metal film reaches a predetermined thickness; ,
and a step of separating the electrolyte membrane from the substrate while pumping air between the substrate on which the metal coating is formed and the electrolyte membrane. Method. 4. The method for forming a metal film according to claim 3, further comprising a step of replacing the plating solution contained in the container with air after the step of forming the metal film and before the step of separating. Deposition method.

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