JP7632262B2 - Metal film forming apparatus and method - Google Patents

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.

Conventionally, a metal coating has been formed by depositing a metal on the surface of a substrate (for example, see Patent Document 1). Patent Document 1 proposes a metal coating forming device that includes an anode, an electrolyte membrane disposed between the anode and the substrate serving as the cathode, a power supply unit that applies a voltage between the anode and the substrate, and a container that contains an electrolyte solution containing metal ions between the anode and the electrolyte membrane.

In this film forming device, with the electrolyte membrane in contact with the substrate, a voltage is applied between the anode and the substrate using a power supply. This causes the metal ions contained in the electrolyte membrane to migrate to the surface of the substrate in contact with the electrolyte membrane and are reduced on the surface of the substrate. As a result, the metal is deposited on the surface of the substrate, forming a metal film.

JP 2016-169399 A

By the way, in order to increase the film formation speed using the above-mentioned film formation device, a metal film may be formed using a heated electrolyte. In this case, the heated electrolyte is contained in a container, and the heat of the electrolyte is transferred to the container and the electrolyte membrane.

However, after the formation of the metal film is completed, the electrolyte in the container may be replaced with air. At this time, the electrolyte attached to the electrolyte membrane may evaporate into the atmosphere in the container due to the heat of the electrolyte membrane. In particular, the heat stored in the container continues to be transferred to the electrolyte membrane, which may promote the continued evaporation of the electrolyte solution and cause the electrolyte membrane to become dry. This drying may cause plating components (such as copper sulfate) to precipitate inside or on the surface of the electrolyte membrane. If an attempt is made to form a membrane again when plating components have precipitated on the electrolyte membrane, pits or pinholes may occur in the metal film.

The present invention has been made in consideration of these points, and its purpose is to provide a metal film forming device and a film forming method that improve the film forming quality by suppressing the evaporation of the electrolyte solution adhering to the electrolyte membrane.

In consideration of the above-mentioned problems, the present invention provides a film-forming apparatus for forming a metal film, the film-forming apparatus comprising an anode, an electrolyte membrane disposed between the anode and a substrate, a container that contains the anode and a plating solution and has an opening on the substrate side covered with the electrolyte membrane, and a power supply unit that applies a voltage between the anode and the substrate that serves as a cathode, and in a state in which the electrolyte membrane is in contact with the substrate, a metal film derived from metal ions in the plating solution is formed on the surface of the substrate by applying the voltage, the film-forming apparatus comprising a mounting table on which the substrate is placed, a lifting device that raises and lowers 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, a heating device that heats the plating solution so that the temperature of the plating solution contained in the container becomes a predetermined temperature, a replacement mechanism that replaces the plating solution contained in the container with air, and a plating solution separated from the substrate. The electrolyte membrane further includes a cooling device for cooling the electrolyte membrane, and a control device for controlling the lifting operation by the lifting device, the application operation by the power supply unit, the replacement operation by the replacement mechanism, and the cooling operation by the cooling device. The control device controls the lifting operation by the lifting device so that the substrate contacts the electrolyte membrane, controls the application operation by the power supply unit until the metal film reaches a predetermined thickness while the plating solution heated by the heating device is contained in the container after the substrate contacts the electrolyte membrane, controls the replacement operation by the replacement mechanism so that the plating solution is replaced with air after the application operation by the power supply unit is completed, controls the lifting operation by the lifting device so that the electrolyte membrane is separated from the substrate, and controls the cooling operation by the cooling device to cool the electrolyte membrane separated from the substrate.

According to the present invention, first, the control device controls the lifting operation of the lifting device so that the substrate contacts the electrolyte membrane. This control allows the electrolyte membrane to contact the substrate placed on the placement table.

Next, after the substrate comes into contact with the electrolyte membrane, the plating solution heated by the heating device is contained in a container, and the application operation by the power supply unit is controlled until the metal film reaches a predetermined thickness. With this control, when a voltage is applied between the anode and the substrate with the electrolyte membrane in contact with the substrate, metal ions move to the surface side of the substrate via the electrolyte membrane and are reduced on the substrate surface, causing the metal to precipitate. As a result, a metal film derived from the precipitated metal can be formed on the substrate surface. In particular, the use of a heated plating solution can increase the speed at which the metal film is formed.

Next, after the power supply unit has finished applying power, the control device controls the replacement operation by the replacement mechanism so that the plating solution is replaced with the atmosphere. As a result, the plating solution contained in the container is replaced with the atmosphere. Next, the control device controls the lifting operation by the lifting device so that the electrolyte membrane is separated from the substrate. With this control, the plating solution contained in the container is replaced with the atmosphere, and then the electrolyte membrane is separated from the substrate, thereby preventing the electrolyte membrane from deforming due to the weight of the plating solution.

Since the electrolyte membrane separated from the substrate is exposed, the control device controls the cooling operation of the cooling device to cool the electrolyte membrane. Here, for example, during the above-mentioned film formation, the container and the electrolyte membrane are heated by the heat of the plating solution, and the heated plating solution is discharged from the container when it is replaced with the atmosphere. At this time, the plating solution attached to the electrolyte membrane evaporates into the replaced atmosphere, and the heat of the container is further transferred to the electrolyte membrane. However, in the present invention, even if the heat from the container is transferred to the electrolyte membrane, the electrolyte membrane is cooled by the cooling device, so that the electrolyte membrane can be prevented from drying out due to the heat transferred from the container. As a result, when forming a metal film again, film formation defects caused by the precipitation of components from the plating solution due to drying can be prevented.

The cooling device may, for example, be equipped with a heat sink that comes into contact with the electrolyte membrane to absorb heat from the electrolyte membrane and dissipate it, or may be equipped with a spray nozzle that sprays cooling water or the like. However, in a more preferred embodiment, the cooling device is equipped with an air nozzle that cools the electrolyte membrane with air. According to the present invention, the electrolyte membrane is cooled with air from an air nozzle, so that the electrolyte membrane can be cooled easily. In particular, since the electrolyte membrane can be cooled in a dry environment with air from outside the membrane forming apparatus without using liquid or the like, cooling can be achieved more simply and in a clean environment.

This specification also discloses a method for forming a metal film as the present invention. The method for forming a metal film according to the present invention is a method for forming a metal film derived from the metal ions contained in the electrolyte film on the surface of the substrate by applying a voltage between the anode and the substrate, which is a cathode, in a state in which an electrolyte film that has been in contact with a plating solution containing metal ions is brought into contact with the substrate, and the method includes the steps of: bringing the electrolyte film covering the opening formed in a container into contact with the substrate arranged opposite the electrolyte film, applying a voltage between the anode and the substrate in a state in which the heated plating solution is contained in the container until the metal film reaches a predetermined thickness, thereby forming the metal film; replacing the plating solution contained in the container with the atmosphere after forming the metal film; removing the electrolyte film from the substrate after replacing the plating solution with the atmosphere; and cooling the electrolyte film removed from the substrate.

According to the present invention, first, the electrolyte membrane is brought into contact with the substrate, and then a voltage is applied between the anode and the substrate while the heated plating solution is contained in a container. This causes metal ions to migrate to the surface side of the substrate via the electrolyte membrane and are reduced on the surface of the substrate, resulting in the deposition of metal. As a result, a metal film derived from the deposited metal is formed. By applying this voltage until the metal film reaches a predetermined thickness, a metal film of the desired thickness can be formed.

Next, after the metal film is formed, the plating solution contained in the container is replaced with air before the solid electrolyte membrane is separated from the substrate. Next, after the plating solution has been replaced with air, the electrolyte membrane is separated from the substrate. In this way, even if the electrolyte membrane is separated from the substrate, the plating solution contained in the container has been replaced with air, so that the electrolyte membrane can be prevented from deforming due to the weight of the plating solution.

In addition, since the electrolyte membrane is exposed after being separated from the substrate, it can be easily cooled. During film formation, the container and electrolyte membrane are heated by the heat of the plating solution, and the heated plating solution is discharged from the container when the plating solution is replaced with air. At this time, the plating solution attached to the electrolyte membrane evaporates into the replaced air, and the heat of the container, which has a larger heat capacity than the electrolyte membrane, is transferred to the electrolyte membrane. However, in the present invention, even if the heat from the container is transferred to the electrolyte membrane, the electrolyte membrane is cooled, so that the electrolyte membrane is prevented from drying due to the heat transferred from the container, and the precipitation of the components of the plating solution can be suppressed. As a result, when a metal coating is formed again, poor film formation caused by the precipitation of components from the plating solution due to this drying can be suppressed.

In a more preferred membrane forming method, the electrolyte membrane is cooled by blowing air onto it. According to this embodiment, the electrolyte membrane is cooled by blowing air onto it, so that the electrolyte membrane can be cooled easily. In particular, compared to cooling using ice, dry ice, etc., the electrolyte membrane can be cooled in a dry environment more simply and inexpensively. This makes it possible to cool the electrolyte membrane more easily and in a cleaner environment.

According to the present invention, the evaporation of the electrolyte solution adhering to the electrolyte membrane can be suppressed, thereby improving the quality of the membrane.

1 is a schematic cross-sectional view of a metal film forming apparatus according to an embodiment of the present invention. 2A is a schematic plan view of the cooling device shown in FIG. 1 as viewed from below, and FIG. 2B is a cross-sectional view taken along the line BB of FIG. 2A is a schematic plan view of a modified example of the cooling device shown in FIG. 2A, and FIG. 2B is a cross-sectional view taken along the line CC of FIG. 2 is a flowchart illustrating control of the film forming apparatus shown in FIG. 1 . 5 is a cross-sectional view for explaining the contact step shown in FIG. 4 by using the film forming apparatus shown in FIG. 1. 5 is a cross-sectional view for explaining the film forming process shown in FIG. 4 by using the film forming apparatus shown in FIG. 1. 5 is a cross-sectional view for explaining the replacement step shown in FIG. 4 using the film forming apparatus shown in FIG. 1. 5 is a cross-sectional view for explaining the separation step shown in FIG. 4 by using the film forming apparatus shown in FIG. 1.

The following describes a metal film deposition device according to an embodiment of the present invention with reference to the drawings.

As shown in FIG. 1, the film forming apparatus 1 includes an anode 11, an electrolyte membrane 13 disposed between the anode 11 and the substrate W, and a container 15 that contains the anode 11 and plating solution L and has an opening 15g that opens toward the substrate W and is covered with the electrolyte membrane 13. Note that in FIG. 1, the container 15 does not contain plating solution L. The film forming apparatus 1 further includes a power supply unit 19 that applies a voltage between the anode 11 and the substrate W that serves as the cathode, a mounting table 20 on which the substrate W is placed, and a lifting device 70 that lifts and lowers the container 15.

In the film forming apparatus 1, the lifting device 70 brings the electrolyte membrane 13 into contact with the substrate W placed on the mounting table 20, and the power supply unit 19 applies a voltage between the anode 11 and the substrate W to form a metal film on the surface wa of the substrate W. During film formation, metal ions contained inside the electrolyte membrane 13 from the plating solution L are reduced on the surface wa of the substrate W, causing the metal derived from the metal ions to precipitate, and the precipitated metal forms a metal film F (see, for example, FIG. 6).

The substrate W functions as a cathode. The material of the substrate W is not particularly limited as long as it functions as a cathode (i.e., a surface having electrical conductivity), and may be made of a metal material such as copper, silver, gold, nickel, aluminum, or iron, or the surface of a resin, ceramic, or the like may be coated with a metal layer made of the above-mentioned metal.

The mounting table 20 is made of a conductive material and is disposed below the container 15 so that the substrate W faces the electrolyte membrane 13. The mounting table 20 has a recess 21 formed therein for accommodating the substrate W. The substrate (specifically, the cathode) W is electrically connected to the negative electrode of the power supply unit 19 via the mounting table 20. If the mounting table 20 is made of an insulating material, the negative electrode of the power supply unit 19 may be directly connected to the substrate W via a wire.

The anode 11 is attached to the container 15 described later so as to face the mounting table 20 (specifically, the substrate W), and is electrically connected to the positive electrode of the power supply unit 19 via a conductor or the like. The anode 11 has a shape corresponding to the film formation area of the substrate W. The film formation area of the substrate W is the surface wa of the substrate W facing the anode 11 that acts as a cathode. The anode 11 is a non-porous (for example, non-porous) anode made of the same metal as the metal coating, and is a block-shaped or flat anode. The anode 11 is made of the same metal as the metal coating, and may be soluble or insoluble in the plating solution L. However, as long as the required surface area is satisfied, the anode may be porous, mesh, or metal balls laid out in a container.

When the anode 11 is soluble in the plating solution L, examples of the material include copper, nickel, silver, and tin. In this embodiment, there is no particular limitation as long as the anode 11 dissolves when a voltage is applied using the power supply unit 19. When the anode 11 is insoluble in the plating solution L, examples of the material include platinum, titanium, and titanium alloys.

As described above, the plating solution (electrolyte) L is a solution containing the metal of the metal film to be formed in an ionic state, and examples of such metals include copper, nickel, silver, and tin. The plating solution L is an aqueous solution in which such 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 L can be an aqueous solution of nickel nitrate, nickel phosphate, nickel succinate, nickel sulfate, nickel pyrophosphate, or nickel sulfamate. For example, when the metal is copper, the plating solution L can 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 by contacting it with the plating solution L described above. The electrolyte membrane 13 is not particularly limited as long as the metal ions can be reduced in the substrate W when a voltage is applied from the power supply unit 19, and a metal derived from the metal ions can be precipitated. Examples of the material of the electrolyte membrane 13 include fluorine-based resins such as Nafion (registered trademark) manufactured by DuPont, hydrocarbon-based resins, polyamic acid resins, and resins with ion exchange functions such as Selemion (CMV, CMD, CMF series) manufactured by Asahi Glass Co., Ltd.

As shown in FIG. 1, the container 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 container 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. The anode 11 is attached to the inner surface of the container 15, and an opening 15g that opens to the side of the substrate W is formed at a position opposite the anode 11. The opening 15g opens downward, and the electrolyte membrane 13 is attached so as to seal this opening 15g. In this embodiment, the periphery of the electrolyte membrane 13 is sandwiched between the main body 15a and the frame 15b of the container 15, thereby attaching the electrolyte membrane 13 to 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 the storage space S formed between them is filled with the plating solution L during film formation. In this way, the container 15 is structured so that the plating solution L contained in the container space S comes into direct contact with the anode 11 and the electrolyte membrane 13.

The container 15 is formed with a supply flow path 15c for supplying the plating solution L to the storage space S, and a discharge flow path 15d for discharging the plating solution L from the storage space S. The supply flow path 15c and the discharge flow path 15d are connected to the storage space S. Both the supply flow path 15c and the discharge flow path 15d are connected to the storage space S near the electrolyte membrane 13.

The lifting device 70 is a device that lifts and lowers at least one of the container 15 and the mounting table 20 so that the electrolyte membrane 13 and the substrate W can be moved toward and away from each other. In this embodiment, the mounting table 20 is fixed and does not move, and the lifting device 70 lifts and lowers only the container 15. Specifically, as shown in FIG. 1 and FIG. 5, the lifting device 70 includes a device body 71 and a rod 72 that moves linearly relative to the device body 71, and the rod 72 is fixed to the upper part of the container 15. The lifting device 70 may be a known electric actuator that converts the rotation of a motor such as a servo motor into linear motion. As long as the electrolyte membrane 13 can be moved toward and away 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.

The following describes the circulation mechanism for circulating the plating solution L in the film forming apparatus 1, the cooling device 40 for cooling the electrolyte membrane 13, and the control device 60. The film forming apparatus 1 includes, as a circulation mechanism, a tank 17 connected to the container 15 for storing the plating solution L discharged from the container 15, and a pump 18 connected to the tank 17 for pumping the plating solution L from the tank 17 to the container.

The tank 17 is provided with an electric heating device 90 for heating the plating solution L. The heating device 90 is not particularly limited in terms of the heating method, and may be, for example, a steam heater, as long as it can heat the plating solution L to a predetermined temperature. In this embodiment, the plating solution L contained in the tank 17 is heated by the heating device 90, and the heated plating solution L can be supplied from the tank 17 to the storage space S of the storage body 15 by the pump 18, thereby increasing the film formation speed of the metal film F. In this embodiment, the heating device is provided in the tank 17, but is not limited to the tank 17 as long as the metal film can be formed using the heated plating solution L. For example, as long as the film can be formed using the plating solution L heated to a predetermined temperature, the heating device may be provided in the storage body 15 or in the supply path 87 between the tank 17 and the storage body 15. In this embodiment, the "path" refers to a flow path formed by piping through which the plating solution L or air in the atmosphere (i.e., the atmosphere) flows.

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

The container 15 is connected to discharge paths 83 and 84 that return the plating solution L discharged from the container 15 to the tank 17. In this embodiment, a three-way valve 56 is provided between the discharge paths 83 and 84. In addition to the discharge paths 83 and 84, the three-way valve 56 is connected to an open path 85 that is open to the atmosphere. The three-way valve 56 has a first switching position that connects the discharge paths 83 and 84, and a second switching position that connects the discharge path 83 and the open path 85. Each switching position of the three-way valve 56 is controlled by the control device 60.

6, by rotating the pump 18 in the forward direction and controlling the three-way valve 56 to the first switching position, the plating solution L can be circulated while filling the container 15 with the plating solution L in the film forming apparatus 1. Specifically, the plating solution L contained in the tank 17 is supplied to the container 15 by the pump 18 via the supply path 87, and the plating solution L discharged from the container 15 is returned to the tank 17 via the discharge path 83 and the discharge path 84.

In this embodiment, for example, a pressure adjustment valve (not shown) may be provided in the discharge path 84 to adjust the liquid pressure of the plating solution L discharged from the container 15. This allows the liquid pressure of the plating solution L contained in the storage space of the container 15 to be adjusted to the pressure set by the pressure adjustment valve.

On the other hand, as shown in FIG. 7, if the pump 18 is rotated in reverse and the three-way valve 56 is controlled to the second switching position, the plating solution L contained in the container 15 can be replaced with air. Specifically, when the pump 18 is rotated in reverse with the three-way valve 56 in the second switching position, air is sucked in from the open path 85 and flows into the container 15 via the exhaust path 83, and the plating solution L contained in the container 15 is returned to the tank 17. As a result, the container space S of the container 15 is filled with air (atmospheric air) at atmospheric pressure.

In this embodiment, the replacement mechanism 50 is made up of the three-way valve 56, the open path 85, and the pump 18. However, the replacement mechanism is not limited to this type of device mechanism, and may be a mechanism in which a 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. In addition, the replacement mechanism may be a mechanism that pressure-feeds air into the storage space S of the container 15 using the air pump 51 described below or a different air pump. As long as the plating solution L can be replaced with air in the container 15, the configuration of the replacement mechanism is not particularly limited.

In this embodiment, as shown in FIG. 1, a cooling device 40 is provided for cooling the electrolyte membrane 13 separated from the substrate W. The cooling device 40 is provided with an air nozzle 41 for cooling the electrolyte membrane 13 with air A.

2(a), the air nozzle 41 is provided with an insertion/removal mechanism 42 that inserts and removes the air nozzle 41 from the device body 43. The device body 43 is connected to a compressor (not shown) that supplies compressed air A or an air pipe (not shown). The insertion/removal mechanism 42 is a cylindrical member that can be nested to freely accommodate the air nozzle 41 inside. The insertion/removal mechanism 42 is connected to a linear actuator (not shown) provided in the device body 43. In this embodiment, the actuator is driven to move the air nozzle 41 between the substrate W and the electrolyte membrane 13 during cooling, and to move the air nozzle 41 inside the insertion/removal mechanism 42 at other times.

As shown in FIG. 2(b), the air nozzle 41 is a cylindrical header pipe 41a through which compressed air flows from the device body 43, with multiple through holes 41b formed along the longitudinal direction. The through holes 41b are formed toward the electrolyte membrane 13. The air nozzle 41 is connected to an air supply path (not shown) that supplies compressed atmospheric air, and air is supplied to the air nozzle 41 by an opening/closing valve (not shown) provided in the air supply path.

In this way, when the above-mentioned on-off valve is opened and compressed air A is flowed through the air nozzle 41, the air A can be blown toward the electrolyte membrane 13 from the through hole 41b. As a result, as shown in Figures 2(a) and (b), the blown air A flows along the surface of the electrolyte membrane 13 toward the edge of the electrolyte membrane 13. This allows the air A to efficiently cool the heat transferred from the container 15 to the periphery of the electrolyte membrane 13. Since cooling can be performed in a dry environment from outside the membrane forming device 1 using air A without using liquid or the like, cooling of the electrolyte membrane 13 can be achieved more simply and in a clean environment. Note that, in this specification, "air" refers to compressed air, and "air" refers to air at atmospheric pressure.

The cooling device 40 may further include an air nozzle 41 that surrounds the electrolyte membrane 13 in plan view, as in the modified example shown in FIG. 3(a). The air nozzle 41 has a frame-shaped header tube 41a with multiple through holes 41b formed in it. Specifically, the header tube 41a is a tube made by bending a straight steel pipe and joining both ends by welding or the like, and a flexible air supply tube (not shown) is connected to the header tube 41a.

As shown in FIG. 3(b), the through-hole 41b is formed diagonally inward toward the electrolyte membrane 13 (specifically, inclined toward the center of the electrolyte membrane 13). This allows the peripheral edge of the electrolyte membrane 13, which is easily heated by the container 15, to be cooled by air discharged from the through-hole 41b of the air nozzle 41. A pair of guide rails 46, 46 are attached to the air nozzle 41. A flexible tube (not shown) is attached to the air nozzle 41 along the guide rail 46, and compressed air is supplied to the air nozzle 41 through the tube.

During cooling, the air nozzle 41 slides along the guide rail 46 by an actuator (not shown) attached to the air nozzle 41 and is inserted between the substrate W and the electrolyte membrane 13. After cooling, the air nozzle 41 slides along the guide rail 46 to a retracted position away from between the substrate W and the electrolyte membrane 13.

2 and 3, the air nozzle 41 is movable so as to be inserted between the substrate W and the electrolyte membrane 13 during cooling. However, for example, if the electrolyte membrane 13 can be cooled by blowing air A onto it, the air nozzle 41 may be fixed at a position outside the space between the container 15 and the mounting table 20. Also, instead of the air nozzle, a blower having a blower fan or the like may be provided.

The control device 60 controls the lifting operation by the lifting device 70, the application operation by the power supply unit 19, the replacement operation by the replacement mechanism 50 (specifically, the drive of the pump 18 and its rotation direction), the circulation operation by the pump 18, and the cooling operation by the cooling device 40. Note that the application operation by the power supply unit 19 is the operation of a switch that applies a voltage by 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 a calculation device (not shown) that executes the control program. The storage device further stores set values such as the start timing and drive time of the pump 18, the start time and duration of application of power to the power supply unit 19, and the amount of displacement by the lifting device 70. Signals from a pressure sensor (not shown) that measures the pressure in the storage space S of the storage body 15 are input to the control device 60 via an input device or the like.

The control flow of the control device 60 will be described with reference to FIG. 4 below. The control device 60 performs the following series of operations. First, an installation process S1 is performed. Specifically, in this process, a conveying device (not shown) and the like are controlled to install the substrate W on the mounting table 20. At this time, the alignment of the substrate W with respect to the anode 11 attached to the container 15 is adjusted, and the temperature of the substrate W may be adjusted.

Next, the contact step S2 is performed. Specifically, as shown in FIG. 5, the control device 60 controls the lifting operation of the lifting device 70 so that the substrate W comes into contact with the electrolyte membrane 13. This control causes the rod 72 of the lifting device 70 to extend, and the electrolyte membrane 13 covering the opening 15g of the container 15 can be brought into contact with the substrate W.

Next, the liquid supply process S3 is performed. In this process, the control device 60 controls the operation of the pump 18 and controls the three-way valve 56 to the first switching position. As a result, as shown in FIG. 5, by driving the pump 18 in the forward direction, the plating solution L heated to a predetermined temperature by the heating device 90 in the tank 17 can be supplied from the supply path 87 to the storage space S of the storage body 15 and returned to the tank 17 via the discharge paths 83 and 84.

Here, if the pressure of the plating solution L contained in the storage space S can be maintained at a predetermined pressure by the pressure regulating valve described above, the control device 60 may continuously drive the pump 18 during film formation. Also, an on-off valve (not shown) may be provided in the discharge path 83, and when a predetermined pressure is maintained, the control device 60 may close the on-off valve and stop the pump 18. In this embodiment, the electrolyte membrane 13 is brought into contact with the substrate W before the plating solution L is contained in the storage body 15. However, for example, the plating solution L may be supplied to the storage space S of the storage body 15 while the storage body 15 is lowered. It is sufficient that the plating solution L is contained in the storage body 15 and the electrolyte membrane 13 is in contact with the substrate W before the following film formation step S4 is performed.

Next, the film-forming process S4 is performed. In this process, the control device 60 controls the application operation by the power supply unit 19 after the substrate W comes into contact with the electrolyte membrane 13 until the metal film F reaches a predetermined thickness. Specifically, when a voltage is applied between the anode 11 and the substrate W with the plating solution L contained in the container 15 (filled) and the electrolyte membrane 13 in contact with the substrate W, metal ions move to the surface side of the substrate W through the electrolyte membrane 13 and are reduced on the surface wa of the substrate W, causing the metal to precipitate and form the metal film F. By applying such a voltage until the metal film F reaches a predetermined thickness, the metal film F can be formed to a desired thickness.

Next, the replacement step S5 is performed. In this step, the control device 60 controls the replacement operation of the replacement mechanism 50 (specifically, the pump 18 and the three-way valve 56) so that the plating solution L is replaced with the atmosphere after the application operation by the power supply unit 19 is completed. Specifically, the control device 60 switches the three-way valve 56 to the second switching position and reverses the rotation of the pump 18, so that the plating solution L in the storage space S of the storage body 15 is returned to the tank 17 via the supply path 87, as shown in FIG. 7. At the same time, the atmosphere is introduced into the release path 85, and the introduced atmosphere is supplied to the storage space S of the storage body 15 via the exhaust path 83. When almost all of the plating solution L is exhausted from the storage space S, the control device 60 stops the pump 18. Note that FIG. 7 shows a stage in the middle of replacing the plating solution L contained in the storage space with the atmosphere.

Next, the separation step S6 is performed. Specifically, as shown in FIG. 8, the control device 60 controls the lifting operation of the lifting device 70 so that the electrolyte membrane 13 is separated from the substrate W. Through this control, the electrolyte membrane 13 is separated from the substrate W.

Here, for example, during the above-mentioned film formation, the container and the electrolyte membrane are heated by the heat of the plating solution, and in the replacement step S5, the heated plating solution L is discharged from the container 15. At this time, the plating solution L attached to the electrolyte membrane 13 evaporates into the replaced atmosphere, and the heat of the container 15 is further transferred to the electrolyte membrane 13. This may cause the electrolyte membrane 13 to dry out, and plating components may precipitate on the electrolyte membrane 13. Pits and pinholes may occur in the metal coating F formed through the above-mentioned series of steps using the electrolyte membrane 13 in this state. For this reason, in this embodiment, the following cooling step S7 is performed.

In the cooling step S7, the control device 60 controls the cooling operation by the cooling device 40 to cool the electrolyte membrane 13. Specifically, since the electrolyte membrane 13 separated from the substrate W in the separation step S6 is exposed, the air nozzle 41 is inserted between the mounting table 20 and the container 15, and air A is blown from the air nozzle 41 onto the electrolyte membrane 13. To control the cooling operation, the control device 60 controls the movement of the air nozzle 41 using the actuator (not shown) described above, and controls the blowing of air A using an opening/closing valve (not shown) provided in the path for supplying air A.

Finally, the removal process S8 is performed. In this process, the air nozzle 41 after the cooling process S7 is retracted from between the mounting table 20 and the container 15, and a conveying device (not shown) is controlled to remove the substrate W from the mounting table 20. When forming a metal coating F on a new substrate W, this series of processes is repeated.

As described above, according to this embodiment, even if heat from the container 15 is transferred to the electrolyte membrane 13, in the cooling step S7, the electrolyte membrane 13 is cooled by the cooling device 40, so that the electrolyte membrane 13 can be prevented from drying out due to the heat transferred from the container 15. This makes it possible to prevent poor film formation caused by the precipitation of components from the plating solution due to drying when forming the metal film F again.

Using the thermal network method, the temperature of the peripheral part of the electrolyte membrane (the part directly heated by the container) and the temperature of the central part of the electrolyte membrane (the part in contact with the atmosphere replaced by the plating solution) were calculated. Here, it is assumed that the plating solution is heated to 70°C and the metal film is formed using the plating solution. Specifically, the calculation conditions were set to 70°C for the container temperature and 40°C for the atmosphere (air) temperature in the container space. In this state, in the reference example, the temperatures of the peripheral part and the central part of the electrolyte membrane were calculated under the condition that air at a temperature of 25°C was blown for 60 seconds. Meanwhile, in the reference comparative example, the temperatures of the peripheral part and the central part of the electrolyte membrane were calculated under the condition that air was not blown for 60 seconds. These results are shown in Table 1.

(Results and Discussion)
In the reference example, it was found that the electrolyte membrane was cooled by blowing air, which absorbed the heat transferred from the housing to the electrolyte membrane, whereas in the reference comparative example, it was found that the heat from the housing was transferred from the periphery to the center of the electrolyte membrane.

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

In this embodiment, the film formation method is performed under the control of a control device, but for example, the series of operations shown in FIG. 4 may be performed manually without being controlled by a control device, or some of them may be performed by a control device.

1: Film forming device, 11: Anode, 13: Electrolyte membrane, 15: Container, 15g: Opening, 17: Tank, 19: Power supply, 20: Mounting table, 40: Cooling device, 41: Air nozzle, 50: Replacement mechanism, 60: Control device, 70: Lifting device, W: Substrate, L: Plating solution

Claims (4)

An anode;
an electrolyte membrane disposed between the anode and a substrate;
a container that contains the anode and the plating solution and has an opening that opens to the substrate side and is 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 formation apparatus for forming a metal film derived from metal ions in the plating solution on a surface of the substrate by applying the voltage while the electrolyte membrane is in contact with the substrate, the film formation apparatus comprising:
The film forming apparatus includes:
A mounting table on which the base material is placed;
a lifting device that lifts and lowers at least one of the container and the stage so that the electrolyte membrane can be brought into contact with and separated from the base material;
a heating device that heats the plating solution contained in the container so that the temperature of the plating solution becomes a predetermined temperature;
a replacement mechanism for replacing the plating solution contained in the container with the atmosphere;
a cooling device for cooling the electrolyte membrane, the electrolyte membrane being spaced apart from the substrate;
and a control device that controls the lifting operation by the lifting device, the application operation by the power supply unit, the replacement operation by the replacement mechanism, and the cooling operation by the cooling device,
The control device includes:
controlling the lifting and lowering operation of the lifting device so that the base material comes into contact with the electrolyte membrane;
After the base material comes into contact with the electrolyte membrane, in a state in which the plating solution heated by the heating device is contained in the container, an application operation by the power supply unit is controlled until the metal coating reaches a predetermined thickness;
After the application operation by the power supply unit is completed, the replacement operation by the replacement mechanism is controlled so that the plating solution is replaced with the atmosphere;
controlling a lifting operation by the lifting device so as to separate the electrolyte membrane from the base material;
A metal film forming apparatus, comprising: a cooling device that controls a cooling operation so as to cool the electrolyte membrane separated from the substrate. The metal film forming apparatus according to claim 1, characterized in that the cooling device is equipped with an air nozzle that cools the electrolyte membrane with air. A film formation method for forming a metal coating derived from the metal ions contained in the electrolyte membrane on a surface of the substrate by applying a voltage between an anode and the substrate, which serves as a cathode, in a state in which an electrolyte membrane, which has been in contact with a plating solution containing metal ions, is brought into contact with the substrate, the method comprising the steps of:
a step of contacting the electrolyte membrane covering the opening formed in the container with the base material disposed opposite the electrolyte membrane, and then applying a voltage between the anode and the base material while the heated plating solution is contained in the container until the metal film reaches a predetermined thickness, thereby forming the metal film;
replacing the plating solution contained in the container with air after the metal coating is formed;
replacing the plating solution with air, and then separating the electrolyte membrane from the substrate;
cooling the electrolyte membrane separated from the substrate;
A method for forming a metal film, comprising: The method for forming a metal film according to claim 3, characterized in that the electrolyte membrane is cooled by blowing air onto it.

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