Metal film forming apparatus

Abstract

To provide a metal coating film deposition apparatus that improves the film quality by supplying an additive to an electrolytic solution.SOLUTION: A film deposition apparatus 1A includes: an anode 11; a solid electrolyte membrane 13 arranged between the anode and a base B; a power supply unit 14 using the base as a cathode to apply a voltage between the anode and the base; a housing 15 housing the anode and an electrolytic solution L containing metal ions and covering an opening 15a opened on the side of the base with the solid electrolyte membrane; and a liquid tank T supplying the electrolytic solution to the housing. A control device 90 of the film deposition apparatus calculates an integrated current value obtained by integrating a current value energized from the anode to the base according to the passage of time by applying the voltage by the power supply unit, estimates the consumption of an additive based on the integrated current value, and controls an additive replenishing device 30 so that the additive corresponding to the estimated consumption is replenished to the electrolytic solution.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a film forming apparatus for forming a metal film on the surface of a substrate.

Background Art

[0002] Conventionally, metal has been deposited on the surface of a substrate to form a metal film (for example, Patent Document 1). Patent Document 1 describes a metal film forming apparatus including an anode, a solid electrolyte film disposed between the anode and a substrate serving as a cathode, a power supply unit that applies a voltage between the anode and the substrate, and a liquid storage unit that stores an electrolytic solution containing metal ions between the anode and the solid electrolyte film.

[0003] In this film forming apparatus, with the solid electrolyte film in contact with the substrate, a voltage is applied between the anode and the substrate using the power supply unit. As a result, the metal ions contained in the solid electrolyte film move to the surface of the substrate in contact with the solid electrolyte film, are reduced on the surface of this substrate, and metal is deposited on the surface of the substrate. Thereby, a metal film made of the deposited metal is formed on the surface of the substrate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, when forming a metal film using the above film forming apparatus, it is common to add an additive to the electrolytic solution for the purpose of improving the film forming quality. However, since this additive is consumed when a metal film is formed on the substrate, if the formation of the metal film is continuously performed, the amount of the additive contained in the electrolytic solution decreases. Thus, when film formation is carried out with the amount of the additive reduced, there is a risk that the film formation quality may deteriorate.

[0006] The present invention has been made in view of such a point, and an object thereof is to provide a film forming apparatus for a metal film that improves the film forming quality by supplying an additive to an electrolytic solution.

Means for Solving the Problems

[0007] In view of the above problems, a film forming apparatus for a metal film according to the present invention includes an anode, a solid electrolyte membrane disposed between the anode and a base material, a power supply unit that applies a voltage between the anode and the base material with the base material as a cathode, a container that houses the anode and an electrolytic solution containing metal ions and covers an opening opened on the side of the base material with the solid electrolyte membrane, and a liquid tank connected to the container that supplies the electrolytic solution to the container. A film forming apparatus for a metal film that forms a metal film derived from the metal ions on the surface of the base material by applying a voltage between the anode and the base material with the solid electrolyte membrane in contact with the base material and reducing the metal ions contained inside the solid electrolyte membrane, wherein the electrolytic solution further contains an additive, and the film forming apparatus includes an additive supply device that supplies the additive to the electrolytic solution housed in the liquid tank, and a control device that controls the supply of the additive by the additive supply device. The control device calculates an integrated current value obtained by integrating the current value passed from the anode to the base material over time by applying a voltage by the power supply unit, estimates the consumption amount of the additive based on the integrated current value, and controls the additive supply device so that the additive corresponding to the estimated consumption amount is supplied to the electrolytic solution.

[0008] In the above-described film forming apparatus, when forming a metal film on the surface of a substrate, additives are consumed together with metal ions. In this regard, according to the film forming apparatus of the present invention, the control device calculates an integrated current value obtained by integrating the current value passed from the anode to the substrate over time. The integrated current value is the sum of the values obtained by multiplying the current value passed from the anode to the substrate by the energization time at that current value. As the metal film is formed on the surface of the substrate, the integrated current value increases, and the consumption amount of the additive increases together with the metal ions contained in the electrolytic solution. Thus, there is a correlation between the integrated current value and the consumption amount of the additive. Therefore, the control device can estimate the consumption amount of the additive used for forming the metal film from the integrated current value based on, for example, the correlation obtained in advance through experiments or the like. The control device can determine the consumption amount of this additive as the amount of the additive to be replenished to the electrolytic solution. The control device controls the additive replenishing device to replenish the electrolytic solution with an amount of the additive corresponding to the estimated consumption amount. Therefore, it is possible to avoid forming a metal film in a state where the amount of the additive has decreased, and thus the film forming quality can be improved.

[0009] As a preferred embodiment, the film forming apparatus includes a recovery mechanism that recovers the electrolytic solution contained in the container into the liquid tank by replacing the electrolytic solution contained in the container with the atmosphere. The control device controls the recovery mechanism so that the electrolytic solution is recovered into the liquid tank after the formation of the metal film. After the recovery of the electrolytic solution, the control device controls the additive replenishing device so that the additive is replenished to the electrolytic solution in the liquid tank.

[0010] According to this aspect, the additive can be replenished to the electrolytic solution in the liquid tank with all the electrolytic solution stored in the container returned to the liquid tank. Therefore, compared with the case of replenishing the additive to the electrolytic solution stored in the container, the replenished additive before being uniformly diffused in the electrolytic solution does not adhere to the solid electrolyte membrane. Thus, in the liquid tank, the replenished additive can be uniformly mixed with the electrolytic solution. In particular, if the electrolytic solution is stirred in the liquid tank together with the replenished additive, the additive can be uniformly dispersed in the electrolytic solution. Therefore, the concentration unevenness of the additive can be suppressed and the film forming quality can be improved.

[0011] As a preferred aspect, the film forming apparatus includes an additive concentration measuring device for measuring the concentration of the additive contained in the electrolytic solution. The control device determines whether or not the solid electrolyte membrane has been replaced after the electrolytic solution is recovered. When the control device determines that the solid electrolyte membrane has been replaced, the control device estimates the consumption amount of the additive based on the concentration of the additive measured by the additive concentration measuring device. When the control device determines that the solid electrolyte membrane has not been replaced, the control device estimates the consumption amount of the additive based on the integrated current value. The control device controls the additive replenishing device so that the additive corresponding to the estimated consumption amount is replenished to the electrolytic solution.

[0012] According to the experiments of the inventors, additives are easily attached to the solid electrolyte membrane, and when the membrane is replaced, additives in the electrolyte solution are easily carried out of the membrane forming apparatus. Therefore, due to the carry-out of additives when the solid electrolyte membrane is replaced, the actual consumption of additives tends to be greater than the consumption of additives estimated based on the integrated current value. Assuming such a case, in this embodiment, when it is determined that the solid electrolyte membrane has been replaced, the consumption of additives can be accurately estimated based on the measured concentration of the additive, so that a more appropriate amount of additive can be replenished to the electrolyte solution. In addition, since the concentration of the additive in the liquid tank can be measured using the replacement time of the solid electrolyte membrane, it is not necessary to secure a new measurement time. On the other hand, when the membrane is not replaced, the consumption of additives can be estimated based on the integrated current value, so that the consumption of additives can be quickly estimated. Therefore, an appropriate amount of additive can be efficiently replenished to the electrolyte solution.

[0013] In a preferred embodiment, the metal ions are copper ions, the electrolyte is a copper sulfate aqueous solution containing chloride ions in addition to the additive, and the additive is a brightener. The film forming apparatus includes a chloride ion concentration measuring device that measures the concentration of the chloride ions contained in the electrolyte, and a chloride ion supplying device that supplies the chloride ions to the electrolyte contained in the liquid tank. The control device estimates the consumption of the chloride ions based on the concentration of the chloride ions measured by the chloride ion concentration measuring device. The control device controls the chloride ion supplying device so that the chloride ions corresponding to the estimated consumption are supplied to the electrolyte.

[0014] Here, the chloride ions contained in the electrolytic solution assist the function of the brightener (the function of adsorbing to the crystal growth points of crystal nuclei and suppressing crystal growth), and are ions effective for forming a stable and dense copper film. These chloride ions are contained in trace amounts in the electrolytic solution compared to other additives. Thus, since the content of chloride ions in the electrolytic solution is trace, chloride ions may not be consumed in proportion to the integrated current value. Also, chloride ions may decrease due to adhesion to components of the film-forming apparatus or the like. For this reason, it is difficult to estimate the consumption amount of chloride ions from the integrated current value. In this regard, according to the present aspect, the concentration of chloride ions contained in the electrolytic solution is measured, and based on the measured chloride ion concentration, the consumption amount of chloride ions can be accurately estimated, so that an appropriate amount of chloride ions can be replenished to the electrolytic solution.

[0015] As a preferred aspect, the electrolytic solution contains at least two types of additives. The film-forming apparatus has the additive supply devices in numbers corresponding to the types of the additives. The control device estimates the consumption amount of each of the additives based on the integrated current value. The control device controls each of the additive supply devices so that the additives corresponding to the estimated consumption amounts are respectively replenished to the electrolytic solution.

[0016] Thus, the control device can independently estimate the consumption amount of each additive according to the type of the additive. The control device can replenish each additive to the electrolytic solution in an appropriate amount according to the consumption amount of each additive. Therefore, even when a plurality of additives are contained in the electrolytic solution, film formation of the metal film in a state where the amount of the additive has decreased can be avoided, so that the film-forming quality can be improved.

[0017] As a preferred aspect, the anode is soluble in the electrolytic solution. According to this aspect, since the anode dissolves in the electrolytic solution, even when metal ions are consumed with the film formation of the metal film, the metal ions are replenished by the dissolution of the anode. For this reason, while stabilizing the concentration of the metal ions contained in the electrolytic solution, the additives are consumed, so that the amount of the additives replenished to the electrolytic solution can be managed more accurately.

Advantages of the Invention

[0018] According to the present invention, the film formation quality can be improved by replenishing the additive to the electrolytic solution.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0020] Hereinafter, with reference to the drawings, a film forming apparatus for a metal film according to an embodiment of the present invention will be described.

[0021] <First Embodiment> FIG. 1 is a schematic cross-sectional view of a metal film forming apparatus 1A according to a first embodiment of the present invention. FIG. 2 shows a state in which an electrolytic solution L is injected into the film forming apparatus 1A of FIG. 1. FIG. 3 is a flowchart for explaining the control of the film forming apparatus 1A of FIG. 1. FIG. 4 is a graph for explaining an example of a step of replenishing an additive based on the integrated current value in the flowchart of FIG. 3.

[0022] As shown in FIGS. 1 and 2, the film forming apparatus 1A includes an anode 11, a solid electrolyte membrane 13 disposed between the anode 11 and the substrate B, a power supply unit 14 that applies a voltage between the anode 11 and the substrate B with the substrate B as a cathode, and an anode 11 and an electrolytic solution L containing metal ions, and a container 15 having an opening 15a covered with the solid electrolyte membrane 13.

[0023] As shown in FIG. 2, the film forming apparatus 1A applies a voltage between the anode 11 and the substrate B with the solid electrolyte membrane 13 in contact with the substrate B, and reduces the metal ions contained inside the solid electrolyte membrane 13, thereby forming a metal film F derived from the metal ions on the surface B1 of the substrate B. In the present embodiment, for convenience of explanation, it is assumed that the solid electrolyte membrane 13 is disposed below the anode 11, and further the substrate B is disposed below that, and the positional relationship of the constituent members of the film forming apparatus 1A is specified. However, as long as the metal film F can be formed on the surface B1 of the substrate B, it is not limited to this positional relationship. For example, the top and bottom of the film forming apparatus 1A in FIG. 1 may be inverted.

[0024] The substrate B may be any member that functions as a cathode (i.e., a conductive surface). The substrate B may be made of a metal material such as aluminum or iron, or a metal layer such as copper may be coated on the surface of resin, ceramics, or the like. The substrate B is electrically connected to the negative electrode of the power supply unit 14. The base 20 holds the substrate B below the container 15.

[0025] The anode 11 has a shape corresponding to the film-forming region of the base material B. The film-forming region of the base material B means a portion of the surface B1 of the base material B facing the anode 11. The anode 11 is a non-porous (for example, non-porous) anode made of the same metal as the metal film F, and is a block-shaped or flat-plate-shaped anode. Examples of the material of the anode 11 include copper, nickel, gold, silver, platinum, or iridium dioxide. In the present embodiment, the anode 11 is soluble in the electrolytic solution L. That is, the anode 11 dissolves by applying a voltage using the power supply unit 14. However, if the film is formed only with the electrolytic solution L containing metal ions, the anode 11 does not have to dissolve. The anode 11 is electrically connected to the positive electrode of the power supply unit 14.

[0026] The electrolytic solution L is a solution containing the metal of the metal film F to be formed in an ionic state, and examples of the metal include copper, nickel, gold, or silver. The electrolytic solution L is an aqueous solution in which these metals are dissolved (ionized) with an acid such as nitric acid, phosphoric acid, succinic acid, nickel sulfate, or pyrophosphoric acid. For example, when the metal is copper, examples of the electrolytic solution L include an aqueous solution containing copper sulfate, copper pyrophosphate, or the like.

[0027] The electrolytic solution L further contains additives. The electrolytic solution L may contain at least two types of additives. Examples of the types of additives include inhibitors, accelerators, and leveling agents. The inhibitor, for example, acts as a resistance to plating deposition and has a function of relaxing the concentration of local current. The accelerator (brightener) adsorbs to the growth points of crystal nuclei and suppresses crystal growth. For this reason, innumerable new nuclei are generated on the surface of the metal film, and the metal film becomes microcrystalline and dense, and a glossy film is obtained. In addition, the brightener functions to form the metal film F with a certain particle size, so that the adhesion between the metal film F and the base material B is improved. The leveling agent (leveler) preferentially adsorbs to the high-current part and has an effect of suppressing the electrodeposition reaction there. For this reason, the metal film F is preferentially formed in the hole part (recessed part) which is the low-current part, and the metal film F can be made smooth. The additives are added to the electrolytic solution L in an appropriate amount, and it is necessary to appropriately manage the consumption amount thereof.

[0028] The solid electrolyte membrane 13 is a membrane that can be impregnated (contain) with metal ions inside by contacting with the above-described electrolyte solution L, and is a flexible membrane. The solid electrolyte membrane 13 is not particularly limited as long as metal ions can permeate to the substrate B side when a voltage is applied by the power supply unit 14. Examples of the material of the solid electrolyte membrane 13 include fluorine-based resins such as Nafion (registered trademark) manufactured by DuPont, hydrocarbon-based resins, polyamic acid resins, and resins having an ion exchange function such as Ceramion (CMV, CMD, CMF series) manufactured by Asahi Glass Co., Ltd. As shown in FIGS. 1 and 2, the solid electrolyte membrane 13 has a facing surface 13a facing the surface B1 of the substrate B in a state of being attached to the container 15.

[0029] As shown in FIG. 1, the anode 11 and the solid electrolyte membrane 13 are attached to the container 15, and an accommodation space 15d for accommodating the electrolyte solution L is formed by the inner wall surface of the container 15, the anode 11, and the solid electrolyte membrane 13. The container 15 has an opening 15a that opens to the side of the substrate B. The opening 15a opens downward, and the solid electrolyte membrane 13 is attached to the container 15 so as to cover the opening 15a. The anode 11 and the solid electrolyte membrane 13 are arranged apart from each other, and the accommodation space 15d between them is filled with the electrolyte solution L. As shown in FIG. 2, the container 15 has a structure in which the electrolyte solution L accommodated in the accommodation space 15d is in direct contact with the anode 11 and the solid electrolyte membrane 13. The container 15 is made of a material insoluble in the electrolyte solution L.

[0030] Furthermore, a supply channel 15b for supplying the electrolyte solution L to the accommodation space 15d and a discharge channel 15c for discharging the electrolyte solution L from the accommodation space 15d are formed in the container 15. The supply channel 15b is fluidly connected to a liquid supply pipe 50 described later, and the discharge channel 15c is fluidly connected to a liquid discharge pipe 52 described later. The film forming apparatus 1A may have a stirring device (not shown) in the liquid tank T, and the electrolyte solution L stirred by this stirring device may be supplied to the accommodation space 15d through the liquid supply pipe 50 and the supply channel 15b.

[0031] The linear actuator 70 of the film forming apparatus 1A raises and lowers at least one of the container 15 and the base 20 so that the solid electrolyte membrane 13 and the substrate B can be separated from and contacted with each other. In the present embodiment, as an example, the base 20 is fixed and the container 15 is raised and lowered by the linear actuator 70. The linear actuator 70 is an electric actuator and includes, for example, a guide 71 to which a motor (not shown) is attached, and a rod 72 that linearly moves with respect to the guide 71. The rod 72 converts the rotational motion of the motor into a linear motion by, for example, a ball screw or the like (not shown). By this linear actuator 70, the container 15 can be raised and lowered with respect to the base 20, and the solid electrolyte membrane 13 can be separated from and contacted with the substrate B. Note that the linear actuator 70 may be provided below the base 20. In this case, the substrate B can be raised and lowered, and the solid electrolyte membrane 13 can be separated from and contacted with the substrate B.

[0032] Next, a mechanism for circulating the electrolytic solution L in the film forming apparatus 1A will be described.

[0033] As shown in FIG. 1, the liquid tank T of the film forming apparatus 1A stores the electrolytic solution L. The liquid tank T is connected to the container 15 via a pump P. Specifically, the electrolytic solution L in the liquid tank T is sucked by the pump P and supplied to the container 15 via the liquid supply pipe 50. The electrolytic solution L used during film formation is discharged from the container 15 to the liquid tank T via the liquid discharge pipe 52.

[0034] A three-way valve 60 for switching the flow direction of the electrolytic solution L is provided in the liquid supply pipe 50. Specifically, the three-way valve 60 switches between the flow direction of the electrolytic solution L from the liquid tank T to the container 15 through the liquid supply pipe 50 and the flow direction of the electrolytic solution L from the container 15 to the liquid tank T through the liquid return pipe 56 described later. Also, by closing the three-way valve 60, the flow of the electrolytic solution L through the liquid supply pipe 50 and the flow of the electrolytic solution L through the liquid return pipe 56 can be stopped. A pump P for supplying the electrolytic solution L from the liquid tank T to the container 15 is provided in the liquid supply pipe 50. When the pump P rotates forward, the electrolytic solution L is sucked from the liquid tank T into the liquid supply pipe 50. The electrolytic solution L is then pumped through the three-way valve 60 into the accommodation space 15d of the container 15. Note that the pump P has a structure that allows for both forward and reverse rotation. When the pump P rotates forward, as described above, the electrolytic solution L is supplied from the liquid tank T to the container 15. On the other hand, when the pump P rotates in reverse, the electrolytic solution L is recovered from the container 15 to the liquid tank T through the liquid return pipe 56.

[0035] A pressure regulating valve 58 is interposed in the liquid discharge pipe 52, thereby preventing the pressure (liquid pressure) of the electrolytic solution L contained in the accommodation space 15d from exceeding a predetermined pressure. Also, the pressure regulating valve 58 can seal the inside of the accommodation space 15d by closing the three-way valve 60. As a result, the liquid pressure of the electrolytic solution L in the accommodation space 15d can be maintained below a predetermined pressure. Also, a relief valve 62 is interposed between the container 15 and the pressure regulating valve 58 in the liquid discharge pipe 52. The relief valve 62 is opened, for example, when the inside of the liquid discharge pipe 52 becomes a negative pressure (a pressure lower than the atmospheric pressure), and introduces external air into the accommodation space 15d of the container 15.

[0036] In addition, the film forming apparatus 1A includes a recovery mechanism 80 that recovers the electrolytic solution L stored in the container 15 into the liquid tank T by replacing the electrolytic solution L stored in the container 15 with the atmosphere. The recovery mechanism 80 returns the electrolytic solution L from the container 15 to the liquid tank T through the liquid return pipe 56. In the present embodiment, a part of the liquid return pipe 56 shares a part of the liquid supply pipe 50. Note that the liquid return pipe 56 may be a pipe separate from the liquid supply pipe 50.

[0037] The recovery mechanism 80 may include a pump P, a three-way valve 60, and a relief valve 62. In the present embodiment, a case where the pump P is a component of the recovery mechanism 80 will be described. When the three-way valve 60 is switched so that the electrolytic solution L flows from the container 15 toward the liquid tank T, by rotating the pump P in the reverse direction, the electrolytic solution L flows from the container 15 into the liquid tank T through the liquid return pipe 56. That is, when the pump P rotates in the reverse direction, the electrolytic solution L is sucked into the liquid return pipe 56 from the container 15, and the electrolytic solution L is pumped into the liquid tank T. When the pump P continues to rotate in the reverse direction, the relief valve 62 is opened, and the atmosphere is introduced into the accommodation space 15d of the container 15. In this way, the recovery mechanism 80 replaces the electrolytic solution L stored in the accommodation space 15d with the atmosphere by the reverse rotation of the pump P, the switching of the three-way valve 60, and the opening of the relief valve 62. Note that in the present embodiment, an example of the recovery mechanism 80 has been described. For example, the recovery mechanism 80 may recover the electrolytic solution L stored in the accommodation space 15d into the liquid tank T by pumping compressed air from the supply flow path 15b of the container 15. In this case, the replacement of the electrolytic solution L with the atmosphere is completed when the compressed air remains in the accommodation space 15d.

[0038] Next, a mechanism for replenishing an additive to the electrolytic solution L will be described.

[0039] As shown in FIGS. 1 and 2, the film forming apparatus 1A includes an additive supply device 30 and a control device 90. The additive supply device 30 supplies an additive to the electrolytic solution L stored in the liquid tank T via the additive supply pipe 32. For example, the additive supply device 30 may include an additive tank (not shown) that stores the additive and an additive pump (not shown) that pumps the additive stored in the additive tank to the liquid tank T. When the electrolytic solution L contains two or more types of additives, the film forming apparatus 1A has the additive supply device 30 and the additive supply pipe 32 in numbers corresponding to the types of additives. FIGS. 1 and 2 show, as an example, a case where two additive supply devices 30 and two additive supply pipes 32 are provided.

[0040] The control device 90 comprehensively controls the operation of the film forming apparatus 1A. As one of its functions, the control device 90 has a function of controlling the supply of the additive by the additive supply device 30. The control device 90 receives the current value measured by the ammeter A. The control device 90 constantly receives the above-described current value while the film forming apparatus 1A is operating. The ammeter A measures the current value passed from the anode 11 to the base material B by the application of voltage by the power supply unit 14. The control device 90 can transmit and receive information to and from each component of the film forming apparatus 1A by wire or wirelessly.

[0041] With reference to FIGS. 1 to 4, the control of the film forming apparatus 1A by the control device 90 will be described. As shown in FIG. 3, the control device 90 controls a conveying device (not shown) and the like, whereby the base material B is placed on the base 20 (S100). Next, the control device 90 extends the rod 72 of the linear actuator 70 by a predetermined stroke amount. As a result, as shown in FIG. 2, the rod 72 moves downward with respect to the guide 71, the container 15 descends, and the opposing surface 13a of the solid electrolyte film 13 contacts the surface B1 of the base material B (S110).

[0042] Next, the control device 90 switches the three-way valve 60 so that the electrolytic solution L flows from the liquid tank T to the container 15 through the liquid supply pipe 50 (S120). Next, the control device 90 rotates the pump P forward (S130). As a result, the electrolytic solution L is supplied to the container 15 via the liquid supply pipe 50 and the three-way valve 60. The control device 90 drives the pump P in the forward rotation until the electrolytic solution L in the accommodation space 15d reaches a predetermined liquid pressure.

[0043] When the electrolytic solution L in the accommodation space 15d reaches the predetermined liquid pressure, the control device 90 stops driving the pump P (S140). As a result, the supply of the electrolytic solution L from the liquid tank T to the container 15 is stopped. Next, the control device 90 closes the three-way valve 60 (S150). As a result, the container 15 is in a sealed state, and the liquid pressure of the electrolytic solution L is maintained below a predetermined pressure.

[0044] In this way, with the base material B being pressed by the liquid pressure of the electrolytic solution L against the solid electrolyte membrane 13, the control device 90 controls the power supply unit 14 to apply a voltage between the anode 11 and the base material B for a certain period of time (S160). As a result, the metal ions contained in the solid electrolyte membrane 13 move to the base material B and are reduced on its surface B1. As a result, a metal is deposited on the surface B1 of the base material B, and a metal film F with a certain film thickness is formed on the surface B1 of the base material B.

[0045] The control device 90 calculates the integrated current value (S170). The integrated current value (Ah) is obtained by integrating the current value (A) received from the ammeter A over time. More specifically, the integrated current value (Ah) is the sum of the values obtained by multiplying the above current value (A) by the energization time (h) at that current value. Here, the integrated current value being zero means the initial state where the electrolytic solution L with a predetermined additive added is introduced into the film forming apparatus 1, or the state where the additive is supplied to the electrolytic solution L and the integrated current value is reset. The control device 90 calculates the integrated current value according to the energization time when current is passed from the anode 11 to the base material B starting from this state (the state where no voltage is applied). The integrated current value is not reset until it reaches a predetermined threshold value S. When the integrated current value reaches the predetermined threshold value S (in this case, as will be described later, the additive is replenished to the electrolytic solution L), the integrated current value is reset to zero (see FIG. 4). Thereafter, the control device 90 calculates the integrated current value again. The threshold value S is calculated in advance through experiments or the like based on the correlation between the integrated current value and the consumption amount of the additive (the relationship that the consumption amount of the additive increases as the integrated current value increases). For example, when the integrated current value becomes equal to or greater than the threshold value S, it is determined that the additive necessary for forming the metal film F is insufficient. The threshold value S is calculated so that the additive necessary for forming the metal film F is not insufficient.

[0046] Next, the control device 90 controls the recovery mechanism 80 to recover the electrolytic solution L from the container 15 (S180, S190). Specifically, the control device 90 switches the three-way valve 60 so that the electrolytic solution L flows from the container 15 to the liquid tank T through the liquid return pipe 56 (S180). Next, the control device 90 rotates the pump P in the reverse direction for a predetermined time until the recovery of the electrolytic solution L from the container 15 to the liquid tank T is completed (S190). At this time, the relief valve 62 is opened, and air is introduced into the accommodation space 15d of the container 15.

[0047] Next, the control device 90 determines whether or not the integrated current value is equal to or greater than a predetermined threshold value S (Fig. 4) (S200). When it is determined that the integrated current value is equal to or greater than the threshold value S (YES in S200), the control device 90 estimates the consumption amount of the additive consumed in film formation based on the integrated current value (S210). Next, the control device 90 determines that this consumption amount of the additive is the amount of the additive to be replenished to the electrolytic solution L, and replenishes the additive (S220). Specifically, the control device 90 controls the additive supply device 30 so that the additive corresponding to the estimated consumption amount is replenished to the electrolytic solution L in the liquid tank T. Thereafter, the control device 90 resets the integrated current value to zero (Fig. 4). On the other hand, when it is determined that the integrated current value is less than the threshold value S (NO in S200), the control device 90 does not replenish the additive, and this control proceeds to S230 described later.

[0048] Note that in the present embodiment, when it is determined that the integrated current value is equal to or greater than the threshold value S, the additive is supplied. However, for example, without using the threshold value (omitting S200), the consumption amount of the additive may be estimated from the integrated current value (the value obtained by multiplying the current value (A) by the energization time) for each film formation of the metal film F, and the amount of the additive corresponding to this consumption amount may be replenished.

[0049] Here, when the electrolytic solution L contains two or more types of additives, the control device 90 estimates the consumption amount of each additive based on the integrated current value, and controls each of the additive supply devices 30 so that the additive corresponding to the estimated consumption amount is replenished to the electrolytic solution L respectively. Specifically, for each of two or more types of additives, a predetermined threshold value S regarding the integrated current value is calculated. The control device 90 controls the additive supply device 30 to replenish the electrolytic solution L with the type of additive whose integrated current value has become equal to or greater than the threshold value S according to its consumption amount. That is, S200, S210, and S220 shown in FIG. 3 are implemented for each additive. Note that even when the electrolytic solution L contains two or more types of additives, the step of S200 may be omitted. Therefore, the control device 90 can replenish the electrolytic solution L with each additive in an appropriate amount according to the consumption amount of each additive. Thus, even when the electrolytic solution L contains a plurality of additives, it is possible to avoid forming the metal film F in a state where the amount of the additive has decreased.

[0050] As described above, after forming the metal film F (S160), the control device 90 controls the recovery mechanism 80 so that the electrolytic solution L is recovered into the liquid tank T (S180, S190). After the electrolytic solution L is recovered, the control device 90 controls the additive supply device 30 so that an additive is replenished to the electrolytic solution L in the liquid tank T (S200 to S220). In this way, it is possible to replenish the additive to the electrolytic solution L in the liquid tank T in a state where all the electrolytic solution L accommodated in the container 15 has been returned to the liquid tank T. Therefore, the replenished additive before being uniformly diffused in the electrolytic solution L does not adhere to the solid electrolyte membrane 13. Thus, in the liquid tank T, the replenished additive can be uniformly mixed with the electrolytic solution L. Therefore, it is possible to suppress unevenness in the concentration of the additive and improve the film formation quality.

[0051] Next, the control device 90 controls the operation of the linear actuator 70 to separate the solid electrolyte membrane 13 from the base material B (S230). Finally, the control device 90 controls a transport device (not shown) or the like to remove the base material B from the base 20 (S240). As described above, a series of controls of the film forming apparatus 1A using the control device 90 is completed, and this control returns to the start.

[0052] As described above, in the film forming apparatus 1A according to the present embodiment, the control device 90 calculates an integrated current value obtained by integrating the current value passed from the anode 11 to the base material B over time. Therefore, based on the correlation relationship obtained in advance by experiments or the like (that is, as the metal film F is formed on the surface B1 of the base material B, the integrated current value increases, and the consumption amount of the additive increases together with the metal ions contained in the electrolytic solution L), the control device 90 can estimate the consumption amount of the additive used for forming the metal film F from the integrated current value. The control device 90 can determine the consumption amount of this additive as the amount of the additive to be replenished to the electrolytic solution L. The control device 90 controls the additive replenishing device 30 to replenish the electrolytic solution L with an amount of the additive corresponding to the estimated consumption amount. Therefore, since it is possible to avoid forming the metal film F in a state where the amount of the additive has decreased, the film forming quality can be improved.

[0053] Further, in the film forming apparatus 1A, when the anode 11 is soluble in the electrolytic solution L, while stabilizing the concentration of the metal ions contained in the electrolytic solution L, the additive is consumed, so the amount of the additive to be replenished to the electrolytic solution L can be managed more accurately.

[0054] <Second Embodiment> FIG. 5 is a schematic cross-sectional view of a metal film forming apparatus 1B according to the second embodiment of the present invention. FIG. 6 is a flowchart for explaining the control of the film forming apparatus 1B of FIG. 5. The film forming apparatus 1B according to the second embodiment is different from the film forming apparatus 1A according to the first embodiment in that an additive concentration measuring device 40 is provided. Hereinafter, components having the same or similar functions as those of the film forming apparatus 1A according to the first embodiment are denoted by the same reference numerals as those of the film forming apparatus 1A according to the first embodiment, and the description thereof is omitted, and different parts will be described.

[0055] As shown in FIG. 5, the film forming apparatus 1B includes an additive concentration measuring device 40 that measures the concentration of additives contained in the electrolytic solution L. The additive concentration measuring device 40 acquires the electrolytic solution L in the liquid tank T from the sample acquisition pipe 41 using, for example, a pump (not shown). The additive concentration measuring device 40 may be, for example, a CVS (Cyclic Voltammetry Stripping) analyzer. The additive concentration measuring device 40 can individually measure the concentrations of additives (such as inhibitors, accelerators, leveling agents, etc.) contained in the electrolytic solution L. The additive concentration measuring device 40 transmits the measured concentrations of the respective additives to the control device 90.

[0056] Next, the control of the film forming apparatus 1B using the control device 90 will be described. As shown in FIG. 6, after the solid electrolyte membrane 13 is separated from the substrate B (S230), the control device 90 determines whether or not the solid electrolyte membrane 13 has been replaced (S400). That is, the control device 90 determines whether or not the solid electrolyte membrane 13 has been replaced after the electrolytic solution L is recovered. The control device 90 may determine to replace the solid electrolyte membrane 13 when, for example, the film formation of the metal film F has been performed 10 times. The relationship between the number of film formations and the replacement timing of the solid electrolyte membrane 13 is an example and is not limited thereto. The control device 90 controls a membrane replacement device (not shown) to perform the replacement of the solid electrolyte membrane 13.

[0057] When the control device 90 determines that the solid electrolyte membrane 13 has been replaced (YES in S400), the control device 90 determines whether the concentration of the additive measured by the additive concentration measuring device 40 is equal to or lower than a predetermined additive concentration threshold (S430). The concentration of the additive is the ratio of the additive to the electrolytic solution L. Here, as a metal film is formed on the surface B1 of the base material B, the consumption amount of the additive increases together with the metal ions contained in the electrolytic solution L. For this reason, as the consumption amount of the additive increases, the concentration of the additive in the electrolytic solution L obtained by the additive concentration measuring device 40 decreases. Thus, there is a correlation between the consumption amount of the additive and the concentration of the additive. Also, the additive concentration threshold may be calculated in advance, for example, by experiments or the like, based on the above correlation between the consumption amount of the additive and the concentration of the additive (the relationship that as the consumption amount of the additive increases, the concentration of the additive decreases). When the concentration of the additive with respect to the electrolytic solution L (in the case of a plurality of additives, the concentration of each additive) becomes equal to or lower than this additive concentration threshold, it is determined that the additive necessary for forming the metal film F is insufficient. This additive concentration threshold is calculated so that the additive necessary for forming the metal film F is not insufficient.

[0058] When the control device 90 determines that the concentration of the additive with respect to the electrolytic solution L is equal to or lower than the above additive concentration threshold (YES in S430), the control device 90 estimates the consumption amount of the additive based on the concentration of the additive measured by the additive concentration measuring device 40 (S440). Specifically, the control device 90 can estimate the consumption amount of the additive used for forming the metal film F from the concentration of the additive, based on, for example, the above correlation (the relationship that as the consumption amount of the additive increases, the concentration of the additive decreases) obtained in advance by experiments or the like.

[0059] Next, the control device 90 determines that the estimated consumption amount of the additive is the amount of the additive to be replenished to the electrolytic solution L, and performs the replenishment of the additive (S450). Specifically, the control device 90 controls the additive replenishing device 30 so that the additive corresponding to the estimated consumption amount is replenished to the electrolytic solution L. Thereafter, this control proceeds to S240.

[0060] When it is determined that the concentration of the additive in the electrolyte L is not less than the additive concentration threshold (NO in S430), the control device 90 does not replenish the additive, and this control proceeds to S240. In this embodiment, when it is determined that the solid electrolyte membrane 13 has been replaced (YES in S400), without using the additive concentration threshold (omitting S430), each time the solid electrolyte membrane 13 is replaced, the consumption amount of the additive is estimated based on the concentration of the additive (S440), and based on the estimated consumption amount, the additive replenishing device 30 may replenish the additive (S450).

[0061] Further, when the control device 90 determines that the solid electrolyte membrane 13 has not been replaced (NO in S400), it estimates the consumption amount of the additive based on the integrated current value, and controls the additive replenishing device 30 so that the additive corresponding to the estimated consumption amount is replenished to the electrolyte L (S200, S210, S220).

[0062] As described above, in the film forming apparatus 1B according to this embodiment, when it is determined that the solid electrolyte membrane 13 has been replaced, the consumption amount of the additive is estimated based on the measured concentration of the additive. Therefore, even if the additive is taken out of the film forming apparatus 1B during replacement, an appropriate amount of the additive can be replenished to the electrolyte L. On the other hand, when the film has not been replaced, since the consumption amount of the additive is estimated based on the integrated current value, the consumption amount of the additive can be estimated quickly. For this reason, an appropriate amount of the additive can be efficiently replenished to the electrolyte.

[0063] <Modification Example> The film forming apparatus according to the modification example is different from the film forming apparatus 1B according to the second embodiment in that a copper ion concentration measuring device, a copper ion replenishing device, a sulfate ion concentration measuring device, and a sulfate ion concentration adjusting device (none of which are shown) are provided. Hereinafter, the film forming apparatus according to this modification example will be described with the same reference numerals as those of the film forming apparatus 1B according to the second embodiment.

[0064] In the film forming apparatus according to the modification example, the anode 11 is insoluble in the electrolytic solution L, the metal ion is a copper ion, and the electrolytic solution L is an aqueous copper sulfate solution containing sulfate ions. The film forming apparatus according to the present modification example includes a copper ion concentration measuring device that measures the concentration of copper ions contained in the electrolytic solution L, and a sulfate ion concentration measuring device that measures the concentration of sulfate ions contained in the electrolytic solution L. Further, the film forming apparatus includes a copper ion supply device that supplies copper ions to the electrolytic solution L stored in the liquid tank T, and a sulfate ion concentration adjusting device that adjusts the concentration of sulfate ions in the electrolytic solution L stored in the liquid tank T. The copper ion concentration measuring device and the sulfate ion concentration measuring device acquire the electrolytic solution L from, for example, the sample acquisition pipe 41. The copper ion concentration measuring device and the sulfate ion concentration measuring device each measure the concentration of copper ions and the concentration of sulfate ions contained in the electrolytic solution L, and transmit the measured concentration of copper ions and the concentration of sulfate ions to the control device 90.

[0065] In the film forming apparatus according to this modification, before replenishing the additive to the electrolytic solution L using the additive replenishing device 30, the control device 90 controls the copper ion replenishing device and the sulfate ion concentration adjusting device. Specifically, when the control device 90 determines that the solid electrolyte membrane 13 has been replaced (YES in S400 of FIG. 6), it estimates the consumption amount of copper ions based on the concentration of copper ions measured by the copper ion concentration measuring device. Further, the control device 90 estimates, for example, the consumption amount of water (evaporation amount) based on the concentration of sulfate ions measured by the sulfate ion concentration measuring device. The control device 90 controls the copper ion replenishing device so that copper ions corresponding to the estimated consumption amount are replenished to the electrolytic solution L. Further, the control device 90 controls the sulfate ion concentration adjusting device so that water corresponding to the estimated consumption amount is replenished to the electrolytic solution L. When the concentration of sulfate ions increases due to evaporation of the water component from, for example, the copper sulfate aqueous solution, the sulfate ion concentration adjusting device replenishes water to the electrolytic solution L. On the other hand, the sulfate ion concentration adjusting device may replenish sulfate ions when the concentration of sulfate ions in the electrolytic solution L decreases. Thus, in the film forming apparatus according to the modification, after the adjustment of the concentration of copper ions and the concentration of sulfate ions in the electrolytic solution L is completed, the step of replenishing the additive to the electrolytic solution L using the additive replenishing device 30 is performed (S430 to S450 in FIG. 6).

[0066] As described above, according to the film forming apparatus according to this modification, after the adjustment of the concentration of copper ions and the concentration of sulfate ions in the electrolytic solution L is completed, the additive is replenished to the electrolytic solution L using the additive replenishing device 30. Therefore, after the concentrations of copper ions and sulfate ions in the electrolytic solution L are appropriately adjusted, the additive is replenished to the electrolytic solution L. Thus, a more accurate amount of the additive can be replenished.

[0067] <Third Embodiment> FIG. 7 is a schematic cross-sectional view of a metal film forming apparatus 1C according to a third embodiment of the present invention. FIG. 8 is a flowchart for explaining the control of the film forming apparatus 1C of FIG. 7. The film forming apparatus 1C according to the third embodiment is different from the film forming apparatus 1B according to the second embodiment in that a chlorine ion concentration measuring device 42 is provided. Hereinafter, for configurations having the same or similar functions as the film forming apparatuses 1A and 1B described above, the same reference numerals as those of these film forming apparatuses 1A and 1B are given and their descriptions are omitted, and different parts will be described.

[0068] In the film forming apparatus 1C in the present embodiment, the metal ions contained in the electrolytic solution L are copper ions, the electrolytic solution L is a solution containing chlorine ions in an aqueous copper sulfate solution, and the additive is an accelerator (brightener). As shown in FIG. 7, the film forming apparatus 1C includes a chlorine ion concentration measuring device 42 that measures the concentration of chlorine ions contained in the electrolytic solution L, and a chlorine ion supply device 43 that supplies chlorine ions to the electrolytic solution L stored in the liquid tank T.

[0069] The chlorine ion concentration measuring device 42 acquires the electrolytic solution L from the sample acquisition pipe 41 using, for example, a pump (not shown). The chlorine ion concentration measuring device 42 measures the concentration of chlorine ions contained in a trace amount in the electrolytic solution L. The chlorine ion concentration measuring device 42 transmits the measured concentration of chlorine ions to the control device 90.

[0070] The chlorine ion supply device 43 supplies chlorine ions to the electrolytic solution L in the liquid tank T via the chlorine ion supply pipe 43a. For example, the chlorine ion supply device 43 may include a chlorine ion tank (not shown) that stores chlorine ions, and a chlorine ion pump (not shown) that supplies chlorine ions from the chlorine ion tank to the liquid tank T.

[0071] Next, the control of the film forming apparatus 1C using the control device 90 will be described. As shown in FIG. 8, when it is determined that the solid electrolyte membrane 13 has been replaced (YES in S400), the control device 90 determines whether the concentration of chlorine ions measured by the chlorine ion concentration measuring device 42 is equal to or less than a predetermined chlorine ion concentration threshold (S500). The concentration of chlorine ions is the ratio of chlorine ions to the electrolytic solution L. Chlorine ions contained in the electrolytic solution L function to assist the brightener. Therefore, as the consumption amount of the brightener contained in the electrolytic solution L increases, the consumption amount of chlorine ions increases. For this reason, as the consumption amount of chlorine ions increases, the concentration of chlorine ions in the electrolytic solution L obtained by the chlorine ion concentration measuring device 42 decreases. Thus, there is a correlation between the consumption amount of chlorine ions and the concentration of chlorine ions. The chlorine ion concentration threshold may be calculated in advance, for example, by experiments or the like, based on the above correlation between the consumption amount of chlorine ions and the concentration of chlorine ions (the relationship that as the consumption amount of chlorine ions increases, the concentration of chlorine ions decreases). When the concentration of chlorine ions with respect to the electrolytic solution L becomes equal to or less than this chlorine ion concentration threshold, it is determined that the effect of the accelerator (brightener) is not exhibited. This chlorine ion concentration threshold is calculated so that the effect of the brightener can continue to be exhibited.

[0072] When the control device 90 determines that the concentration of chlorine ions with respect to the electrolytic solution L is equal to or less than the chlorine ion concentration threshold (YES in S500), the control device 90 estimates the consumption amount of chlorine ions based on the concentration of chlorine ions measured by the chlorine ion concentration measuring device 42 (S510). Specifically, the control device 90 can estimate the consumption amount of chlorine ions used for forming the metal film F from the concentration of chlorine ions based on, for example, the above correlation (the relationship that as the consumption amount of chlorine ions increases, the concentration of chlorine ions decreases) obtained in advance by experiments or the like.

[0073] Next, the control device 90 controls the chlorine ion supply device 43 so that chlorine ions corresponding to the estimated consumption amount are supplied to the electrolytic solution L (S520). Next, this control proceeds to S430. Thus, according to the film forming apparatus 1C according to the present embodiment, since the concentration of chlorine ions contained in the electrolytic solution L is measured, the concentration of chlorine ions contained in a trace amount in the electrolytic solution L can be accurately measured. Based on this measured chlorine ion concentration, the consumption amount of chlorine ions is estimated, so that the consumption amount of chlorine ions can be accurately grasped. Therefore, an appropriate amount of chlorine ions can be supplied to the electrolytic solution L.

[0074] On the other hand, when it is determined that the concentration of chlorine ions in the electrolytic solution L is not less than the chlorine ion concentration threshold value (NO in S500), the control device 90 does not supply chlorine ions, and this control proceeds to S430. In the present embodiment, when it is determined that the solid electrolyte membrane 13 has been replaced (YES in S400), without using the chlorine ion concentration threshold value (omitting S500), every time the solid electrolyte membrane 13 is replaced, the consumption amount of chlorine ions is estimated based on the concentration of chlorine ions (S510), and based on the estimated consumption amount, the supply of chlorine ions by the chlorine ion supply device 43 may be carried out ( S 520).

Example

[0075] The present invention will be described by the following examples.

[0076] [Example 1] As a substrate for film formation on the surface, a glass epoxy substrate (FR-4) formed by impregnating a cloth made of glass fiber with an epoxy resin was prepared. A copper foil is formed on the surface of this glass epoxy substrate.

[0077] Next, a copper film was formed using the film forming apparatus 1A (Figs. 1 and 2) according to the first embodiment. As the electrolytic solution, an aqueous copper sulfate solution (Cu-BRITE-SED) manufactured by JCU Corporation was used, and a Cu plate was used as the anode. As the film forming conditions, the temperature of the electrolytic solution was set to 42°C, a solid electrolyte membrane (Nafion (manufactured by DuPont)) with a thickness of 8 μm was adhered to the substrate, the hydraulic pressure of the electrolytic solution was 0.6 MPa, and the current density was 7 A / dm 2 , the film forming area was 100 cm 2 , and a copper film was formed with a cumulative film forming time of 1162 seconds. Also, in Example 1, after the second film forming was completed, it was determined that the integrated current value exceeded a predetermined threshold. Therefore, after the second film forming was completed and before the third film forming was started, the additive was replenished by the additive replenishing device according to the consumption amount of the additive estimated based on the integrated current value.

[0078] [Example 2] A copper film was formed using the film forming apparatus 1B (Fig. 5) according to the second embodiment under the same film forming conditions as in Example 1. The difference from Example 1 is that every time one film forming was completed, the additive was replenished by the additive replenishing device according to the concentration of the additive measured by the additive concentration measuring device.

[0079] [Example 3] A copper film was formed using the film forming apparatus 1C (Fig. 7) according to the third embodiment under the same film forming conditions as in Example 2. The difference from Example 2 is that every time one film forming was completed, chlorine ions were replenished by the chlorine ion replenishing device according to the concentration of chlorine ions measured by the chlorine ion concentration measuring device.

[0080] [Comparative Example 1] A copper film was formed in the same manner as in Example 1. The difference from Example 1 is that the additive was not replenished by the additive replenishing device.

[0081] [Comparative Example 2] A copper film was formed in the same manner as in Example 3. The difference from Example 3 is that chlorine ions were not replenished by the chlorine ion replenishing device.

[0082] <Confirmation of Film Formation State> For the substrate formed with a film as described above, a sample piece of 10 mm × 50 mm was prepared, and the adhesion of the copper film to the substrate was measured by a peel test (EZ test manufactured by Shimadzu Corporation). FIG. 9 is a schematic diagram for explaining the peel test in the examples of the present invention. As shown in FIG. 9, the substrate B' of the sample piece was attached to the fixing plate X, and the copper film F' of the sample piece chucked by the device was peeled off in a direction of 90° with respect to the substrate B'. Specifically, while sliding the fixing plate X in the direction of arrow H, the copper film F' was pulled in the direction of arrow V. The results are shown in Table 1 (Example 1, Example 2, Comparative Example 1) and Table 2 (Example 3, Comparative Example 2).

[0083]

Table 1

[0084]

Table 2

[0085] (Results and Discussion) Here, when the adhesion of the copper film F' to the substrate B' of the sample piece is 0.5 kN / m or less, it is determined that the adhesion strength is insufficient (defective), and when the adhesion strength is greater than 0.5 kN / m, it is determined to be good. The above 0.5 kN / m is a value generally used as the threshold for the adhesion strength of the wiring board. As is clear from Table 1, in Examples 1 and 2, it was confirmed that the adhesion strength of the copper film F' to the substrate B' was good in all samples from the first film formation to the fifth film formation. In Example 1, it is considered that after the second film formation was completed and before the third film formation was started, the additive replenishing device replenished the additive, and an appropriate amount of additive (especially brightener) was replenished to the electrolytic solution. Also, in Example 2, it is considered that the additive replenishing device replenished the additive every time one film formation was completed, and an appropriate amount of additive (especially brightener) was replenished to the electrolytic solution.

[0086] In Example 3, it was confirmed that the adhesion of the copper film F' to the substrate B' was good in all samples from the first film formation to the 55th film formation. In Example 3, every time one film formation was completed, the additive replenishing device replenished the additive, and chlorine ions for expressing the effect of the additive (brightener) were also replenished. Therefore, it is considered that the effect of the brightener continues to be expressed.

[0087] On the other hand, in Comparative Example 1, from the third film formation, the adhesion strength of the copper film F' to the substrate B' of the sample piece was less than 0.5 kN / m, and as the number of film formations increased, the adhesion strength decreased. In Comparative Example 1, since the additive was not replenished to the electrolytic solution, when forming the metal film on the surface of the substrate, the additive was consumed together with the metal ions, and the concentration of the additive (especially the brightener) in the electrolytic solution decreased.

[0088] Also, in Comparative Example 2, it was confirmed that from the 51st film formation, the adhesion strength of the copper film F' to the substrate B' of the sample piece was less than 0.5 kN / m. In Comparative Example 2, although the additive (brightener) was replenished by the additive replenishing device every time one film formation was completed, since chlorine ions were not replenished, it is considered that the chlorine ions for expressing the effect of the brightener are insufficient. That is, in Comparative Example 2, since the effect of the brightener was not expressed, the results as shown in the above table were obtained.

[0089] As described above, the preferred embodiments of the present invention have been described. However, the present invention is not limited to the film forming apparatuses 1A, 1B, and 1C according to the above embodiments, and includes all aspects included in the concept and scope of claims of the present invention. Also, in order to achieve the above-described problems and effects, each configuration may be appropriately and selectively combined. For example, the shape, material, arrangement, size, etc. of each component in the above embodiments can be appropriately changed according to the specific aspects of the present invention.

[0090] For example, in the above embodiment, the case where a voltage is applied between the anode 11 and the base material B by the power supply unit 14 in a state where the circulation of the electrolytic solution L is stopped by closing the three-way valve 60 has been described (see S140 to S160 in FIG. 3). However, when the voltage is applied by the power supply unit 14, the three-way valve 60 does not have to be closed. In this case, by continuing the normal rotation of the pump P, the hydraulic pressure of the electrolytic solution L can be maintained at a predetermined pressure.

Explanation of Signs

[0091] 1A, 1B, 1C: Film forming apparatus, 11: Anode, 13: Solid electrolyte membrane, 14: Power supply unit, 15: Container, 15a: Opening, 30: Additive supply device, 40: Additive concentration measuring device, 42: Chloride ion concentration measuring device, 43: Chloride ion supply device, 80: Recovery mechanism, 90: Control device, B: Base material, B1: Surface, F: Metal film, L: Electrolytic solution, T: Liquid tank

Claims

1. An anode, A solid electrolyte membrane disposed between the anode and a substrate, A power supply unit that applies a voltage between the anode and the substrate with the substrate as the cathode, A container that houses the anode and an electrolytic solution containing metal ions and has an opening on the side of the substrate covered with the solid electrolyte membrane, A liquid tank connected to the container for supplying the electrolytic solution to the container, A metal film forming apparatus that forms a metal film derived from the metal ions on the surface of the substrate by applying a voltage between the anode and the substrate with the solid electrolyte membrane in contact with the substrate and reducing the metal ions contained inside the solid electrolyte membrane, The electrolytic solution further contains an additive, The film forming apparatus, An additive supply device that supplies the additive to the electrolytic solution stored in the liquid tank, A recovery mechanism that recovers the electrolytic solution stored in the container into the liquid tank by replacing the electrolytic solution stored in the container with air, An additive concentration measuring device that measures the concentration of the additive contained in the electrolytic solution, A control device that controls the supply of the additive by the additive supply device, The control device, After forming the metal film, controls the recovery mechanism so that the electrolytic solution is recovered into the liquid tank, After recovering the electrolytic solution, controls the additive supply device so that the additive is supplied to the electrolytic solution in the liquid tank, The control device, Calculates an integrated current value obtained by integrating the current value passed from the anode to the substrate over time due to the application of voltage by the power supply unit, After recovering the electrolytic solution, determines whether the solid electrolyte membrane has been replaced, When it is determined that the solid electrolyte membrane has been replaced, estimates the consumption amount of the additive based on the concentration of the additive measured by the additive concentration measuring device, When it is determined that the solid electrolyte membrane has not been replaced, estimates the consumption amount of the additive based on the integrated current value, Controls the additive supply device so that the additive corresponding to the estimated consumption amount is supplied to the electrolytic solution. A metal film forming apparatus characterized by this.

2. The metal ions are copper ions, The electrolytic solution is a solution containing chlorine ions in addition to the additive in an aqueous copper sulfate solution, The additive is a brightener, The film forming apparatus, A chlorine ion concentration measuring device that measures the concentration of the chlorine ions contained in the electrolytic solution, A chlorine ion supply device that supplies the chlorine ions to the electrolytic solution stored in the liquid tank, and the control device, estimates the consumption amount of the chlorine ions based on the concentration of the chlorine ions measured by the chlorine ion concentration measuring device, and controls the chlorine ion supply device so that the chlorine ions corresponding to the estimated consumption amount are supplied to the electrolytic solution. The metal film forming apparatus according to claim 1, characterized in that. **Claim 3** The electrolytic solution contains at least two kinds of additives, and the film forming apparatus has the additive supply devices in numbers corresponding to the kinds of the additives, and the control device, estimates the respective consumption amounts of the additives based on the integrated current value, and controls each of the additive supply devices so that the additives corresponding to the estimated consumption amounts are respectively supplied to the electrolytic solution. The metal film forming apparatus according to claim 1 or 2, characterized in that. **Claim 4** The anode is soluble in the electrolytic solution. The metal film forming apparatus according to any one of claims 1 to 3, characterized in that.

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