Apparatus for forming metal film

Abstract

To provide an apparatus for forming a metal film that can form a metal film with stable quality by supplying a supply tank with replenishment liquid equivalent to the amount of plating solution decreased by film formation.SOLUTION: A film formation apparatus 1 further comprises a supply tank 58 that supplies plating solution L to a container 15, a circulation mechanism 50 that circulates the plating solution L between the supply tank 58 and the container 15, a measuring device 60 that measures the total liquid amount of seepage liquid LR that seeps out from an electrolyte membrane 13 originating from the plating solution L in the container 15 during film formation, and a replenishment device 80 that supplies replenishment liquid LS in a liquid amount corresponding to the total liquid amount to the supply tank 58. The replenishment device 80, through the supply of the replenishment liquid LS, supplies replenishment liquid LS with adjusted metal ion concentration to the supply tank 58 so that the metal ion concentration of the plating solution L contained in the supply tank 58 after film formation approaches the metal ion concentration of the plating solution L contained in the supply tank 58 before film formation.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a metal film forming apparatus. [Background technology]

[0002] As an example of this type of technology, Patent Document 1 proposes a film formation apparatus that forms a metal film on the surface of a substrate by electroplating. The film formation apparatus includes an anode, a container that contains a plating solution, and an electrolyte membrane that covers an opening of the container opposite the anode and thereby seals the plating solution in the container. The film formation apparatus may further include a supply tank that supplies the plating solution to the container and a circulation mechanism that circulates the plating solution between the supply tank and the container. This film formation apparatus applies a voltage between the anode and the substrate, and can form a metal film on the substrate in contact with the electrolyte membrane. During the formation of the metal film, metal ions in the plating solution contained in the container are consumed as the metal film is formed. The circulation mechanism circulates the plating solution between the container and the supply tank, thereby replenishing the metal ions in the plating solution contained in the container. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-122377 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the film formation apparatus disclosed in Patent Document 1, a seepage liquid originating from the plating solution may seep out of the electrolyte membrane onto the substrate during film formation. This reduces the volume of the plating solution in the supply tank by the total volume of the seepage liquid. As a result, the volume of the plating solution in the supply tank may not decrease while maintaining the metal ion concentration of the plating solution contained in the supply tank, making it difficult to control the metal ion concentration in the supply tank. Furthermore, even if a metal salt corresponding to the metal ions used in the film formation is added to the supply tank, the metal salt may remain dissolved and remain in the supply tank. As a result, the quality of the formed metal film may be unstable.

[0005] The present invention has been made in consideration of the above points, and its object is to provide a metal film forming apparatus that can form a metal film of stable quality by replenishing a supply tank with a make-up liquid in accordance with the amount of plating solution that has been reduced by film formation. [Means for solving the problem]

[0006] In view of the above-mentioned problems, the present invention provides a metal film forming apparatus that includes an anode, a container that contains a plating solution, and an electrolyte membrane that covers an opening of the container opposite the anode to seal the plating solution in the container, and that forms a metal film on a substrate in contact with the electrolyte membrane by electrolytic plating. The film forming apparatus further includes a supply tank that supplies the plating solution to the container, a circulation mechanism that circulates the plating solution between the supply tank and the container, a measuring device that measures the total amount of exuded solution that exudes from the electrolyte membrane due to the plating solution in the container during film formation, and a replenishing device that replenishing a replenishing solution to the supply tank in an amount equivalent to the total amount of solution. The replenishing device replenishes the supply tank with the replenishment liquid adjusted to a concentration higher than the metal ion concentration of the plating solution before film formation so that the metal ion concentration of the plating solution contained in the supply tank after film formation approaches the metal ion concentration of the plating solution contained in the supply tank before film formation. [Effects of the Invention]

[0007] According to the present invention, by replenishing the supply tank with a replenisher liquid in accordance with the amount of plating solution that has been reduced due to film formation, a metal film of stable quality can be formed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1A is a schematic diagram of a metal film forming apparatus according to the present embodiment, and FIG. 1B is a schematic diagram showing a state in which a film is formed by the film forming apparatus shown in FIG. [Figure 2] FIG. 2 is a flow diagram of film formation using the film formation apparatus shown in FIG. [Figure 3] 1. FIG. 4 is another flow diagram of film formation using the film formation apparatus shown in FIG. [Figure 4] FIG. 2 is yet another flow chart of film formation using the film formation apparatus shown in FIG. [Figure 5] 1 is a graph showing changes in the concentration of metal ions in the plating solution in the supply tank measured for each film formation cycle. DETAILED DESCRIPTION OF THE INVENTION

[0009] A metal coating forming apparatus 1 according to this embodiment will be described below with reference to Figures 1 to 5. As shown in Figure 1, in this embodiment, the film forming apparatus 1 includes an anode 11, an electrolyte membrane 13, and a power source 14 that applies a voltage between the anode 11 and the substrate B.

[0010] The film formation apparatus 1 further includes a container 15 that contains the anode 11 and the plating solution L, and a mounting table 40 on which the substrate B is placed. The film formation apparatus 1 further includes a linear actuator 70 that raises and lowers the container 15. The linear actuator 70 raises and lowers the container 15 by linearly moving a rod 72 so that the electrolyte membrane 13 and the substrate B can be moved toward and away from each other. The linear actuator 70 has a rod 72 that moves linearly relative to a main body 71, and the container 15 is fixed to the tip of the rod 72.

[0011] The anode 11 is an insoluble anode that does not dissolve in the plating solution L during film formation. The substrate B functions as a cathode. The substrate B may be made of a metal material such as aluminum or copper. The anode 11 is electrically connected to the positive electrode of the power source 14. The negative electrode of the power source 14 is electrically connected to the substrate B via the mounting table 40. The plating solution L is a liquid containing the metal of the metal coating to be formed in an ionic state. Examples of such metals include copper, nickel, gold, and silver.

[0012] The electrolyte membrane 13 is a membrane that can be impregnated (contained) with metal ions together with the plating solution L by contacting the electrolyte membrane 13 with the plating solution L. The electrolyte membrane 13 is a flexible membrane. There are no particular limitations on the material of the electrolyte membrane 13, as long as it allows the metal ions of the plating solution L to migrate to the substrate B side when a voltage is applied from the power source 14. Examples of materials for the electrolyte membrane 13 include resins with ion exchange properties, such as fluororesins such as Nafion (registered trademark) manufactured by DuPont.

[0013] The container 15 has a storage space 15a formed therein for storing the plating solution L. The anode 11 is disposed in the storage space 15a of the container 15. An opening 15d is formed on the side of the storage space 15a facing the substrate B. The opening 15d of the container 15 is covered with the electrolyte membrane 13, so that when the plating solution L is stored in the storage space 15a, the plating solution L in the storage space 15a is sealed by the electrolyte membrane 13.

[0014] The container 15 has a supply port 15b for supplying the plating solution L to the container space 15a and a discharge port 15c for discharging the plating solution L from the container space 15a. The supply port 15b and the discharge port 15c are formed on either side of the container space 15a. The supply port 15b is fluidly connected to a supply pipe 51. The discharge port 15c is fluidly connected to a discharge pipe 52.

[0015] The film forming apparatus 1 includes a supply tank 58. The supply tank 58 is a tank for supplying the plating solution L to the accommodation space 15a of the accommodation body 15. The supply tank 58 accommodates a predetermined amount of the plating solution L, which has been adjusted to a preset metal ion concentration before film formation. The preset metal ion concentration is a concentration that enables the formation of a metal film of stable quality without discoloration such as fading.

[0016] The film forming apparatus 1 includes a circulation mechanism 50. The circulation mechanism 50 circulates the plating solution L between a supply tank 58 and the accommodation body 15. The circulation mechanism 50 includes a supply pipe 51, a discharge pipe 52, and a circulation pump 59. The supply pipe 51 connects the supply tank 58 and the accommodation body 15, and the supply pipe 51 is provided with the circulation pump 59. The discharge pipe 52 connects the supply tank 58 and the accommodation body 15, and the discharge pipe 52 is provided with a pressure adjustment valve 54. The pressure adjustment valve 54 adjusts the pressure (liquid pressure) of the plating solution L in the accommodation space 15a to a predetermined pressure.

[0017] In this embodiment, by driving the circulation pump 59, the plating solution L is sucked from the supply tank 58 into the supply pipe 51 and then pumped from the supply port 15b to the accommodation space 15a. The plating solution L in the accommodation space 15a is returned to the supply tank 58 through the discharge port 15c.

[0018] As shown in FIG. 1(b), when a metal film F is formed in the film-forming apparatus 1, a voltage is applied between the anode 11 and the substrate B. As a result, metal ions contained in the plating solution L migrate through the electrolyte membrane 13 and receive electrons on the surface of the substrate B, resulting in metal deposition. At this time, as the metal ions migrate within the electrolyte membrane 13, the water contained in the plating solution L also becomes a hydrate or the like and migrates toward the substrate B. As a result, during film formation, an exudation liquid LR derived from the plating solution L exudes from the electrolyte membrane 13 onto the substrate B. In particular, when the liquid pressure of the plating solution L in the container 15 is increased by the circulation pump 59 and the electrolyte membrane 13 presses the substrate B with the liquid pressure of the plating solution L, the amount of exudation liquid LR that exudes is likely to increase.

[0019] Therefore, in this embodiment, the film formation apparatus 1 further includes a measuring device 60 and a replenishing device 80. The measuring device 60 is a device that measures the total amount of the exuded liquid LR that originates from the plating solution L in the container 15 and exudes from the electrolyte membrane 13 during film formation.

[0020] In this embodiment, the measuring device 60 includes a measuring instrument 62 that collects the oozing liquid LR during film formation and measures the volume or weight of the collected oozing liquid LR as the total liquid amount, and a control unit 64 that receives a measurement signal of the measured volume or weight of the oozing liquid LR and calculates the total liquid amount (weight or volume) of the oozing liquid LR. In this embodiment, the control unit 64 controls the supply device 80 to control the timing of the replenishment liquid LS and to adjust the concentration of metal ions in the replenishment liquid LS.

[0021] In this embodiment, the exudation liquid LR adhering to the surface of the substrate B after film formation is recovered in the measuring device 62 by blowing air onto the exudation liquid LR or tilting the substrate B. The measuring device 62 measures the total amount of the recovered exudation liquid LR. In addition, in this embodiment, the substrate B is accommodated in the recess 41 formed in the mounting table 40, but a measuring device that measures the weight of the substrate B before and after film formation may be provided in the recess 41 of the mounting table 40 as the measuring device 62. In this case, the total amount (weight) of the exudation liquid LR is the value obtained by subtracting the weight of the formed metal coating F from the increase in weight of the substrate B before and after film formation.

[0022] The measuring device 60 measures the integrated amount of current passed through the anode 11 and the substrate B during the formation of the metal coating F. Specifically, the measuring device 60 includes an ammeter 63 that measures the current flowing from the power source 14 to the anode 11. The control unit 64 calculates the integrated amount of current passed between the anode 11 and the substrate B during the formation of the metal coating F, based on the current value from the ammeter 63. The integrated amount of current here is calculated from the measured current value and the current passing time, and is calculated by a commonly known method.

[0023] Here, the "total amount of liquid" of the exudation liquid LR corresponds to the total amount of liquid that has exuded from the start of film formation until the next time the supply tank 58 is replenished with the replenishment liquid LS by the replenishment device 80, which will be described later. For example, when the replenishment liquid LS is replenished after a metal film F is formed on one substrate B, the total amount of liquid is the total amount of liquid that has exuded in one film formation. When the replenishment liquid LS is replenished after films are formed sequentially on multiple (predetermined number) substrates B, the total amount of liquid is the cumulative total amount of liquid that has exuded when films are formed on all of these substrates B. Similarly, the "cumulative current amount" is the cumulative amount of current that has been applied between the anode 11 and the substrate B from the start of film formation until the next time the replenishment liquid LS is replenished in the supply tank 58 by the replenishment device 80, which will be described later, and is calculated by the control unit 64 over the same period as the measurement of the "total amount of liquid."

[0024] The replenishing device 80 replenishing the supply tank 58 with a volume of replenishment liquid LS equivalent to the total volume of the plating solution. The replenishing device 80 includes a stock solution storage section 81 for storing a stock solution of the plating solution L and a solvent storage section 82 for storing a solvent for the plating solution L. The replenishing device 80 also includes a mixing section 83 for mixing the stock solution from the stock solution storage section 81 with the solvent from the solvent storage section 82 at a predetermined ratio. Here, the stock solution refers to a plating solution in which metal salts are dissolved at their saturated solubility under the temperature conditions of the plating solution L during film formation. This is a solution with a higher concentration than the plating solution L stored in the supply tank 58 before film formation. The solvent refers to water or water containing other additives that do not contain metal salt ions. The replenishing device 80 adjusts the metal ion concentration of the replenishment liquid LS by diluting the stock solution based on, for example, the integrated current amount and the total volume of the plating solution from the control section 64.

[0025] The replenishing device 80 replenishing the supply tank 58 with the replenishing liquid LS adjusted to a metal ion concentration higher than the metal ion concentration of the plating solution L before film formation so that the metal ion concentration of the plating solution L contained in the supply tank 58 after film formation approaches the metal ion concentration of the plating solution L contained in the supply tank 58 before film formation by replenishing the replenishing liquid LS. Specifically, the replenishing device 80 adjusts the metal ion concentration of the replenishing liquid LS based on the integrated current amount and total liquid amount calculated by the control unit 64, and replenishing the adjusted replenishing liquid LS to the supply tank 58. In this embodiment, the replenishing device 80 supplies the replenishing liquid LS to the supply tank 58 when the integrated current amount reaches a predetermined amount (the lower limit of the range in which a film can be formed) by the control unit 64. This ensures that the metal ion concentration of the plating solution L is at a level that allows film formation, thereby enabling the formation of a metal film F of consistent quality.

[0026] In this embodiment, the control unit 64 calculates the consumption amount of metal ions contained in the plating solution L contained in the supply tank 58 from the integrated current amount, and calculates the amount of plating solution L lost from the supply tank 58 during film formation from the total amount of solution. The control unit 64 controls the replenishing device 80 to supply an amount of stock solution corresponding to the consumption amount of metal ions from the stock solution storage unit 81 to the mixing unit 83, to supply an amount of solution corresponding to the total amount of solution from the solvent storage unit 82 to the mixing unit 83, and to send a replenishing solution LS obtained by mixing these from the mixing unit 83 to the supply tank 58.

[0027] However, if the purpose is to reduce the metal ion concentration of the plating solution L contained in the supply tank 58, it is sufficient to prepare a replenishment liquid LS having a higher metal ion concentration than the plating solution L before film formation and supply this to the supply tank 58. For example, the replenishment liquid LS may be an original solution (e.g., a metal ion concentration corresponding to the saturated solubility at the liquid temperature of the plating solution L). Note that the replenishing device 80 may include a pump (not shown), a flow meter (not shown), and a mixer (not shown) to perform such control. Since the configuration and control of these devices are common, detailed description will be omitted. Note that in this embodiment, the metal ion concentration of the replenishment liquid LS produced in the total amount of liquid is lower than that of the original solution and higher than the metal ion concentration of the plating solution L contained in the supply tank 58 before film formation.

[0028] The method for forming a metal film according to this embodiment will be described below with reference to the flow chart in Fig. 2. First, as shown in Fig. 2, in step S1, a plating solution L adjusted to a predetermined metal ion concentration is placed in a supply tank 58. Next, in step S2, a substrate B is placed on a mounting table 40, and as shown in Fig. 1(b), with an electrolyte membrane 13 in contact with the substrate B, the substrate B is pressed by the hydraulic pressure of the plating solution L, and a metal film F is formed on the substrate B by electroplating.

[0029] Next, in step S3, the current passed between the anode 11 and the substrate B is measured by the ammeter 63 and recorded in the control unit 64, and the integrated current amount is calculated by the control unit 64. In step S4, as shown in FIG. 1(a), the linear actuator 70 is used to separate the electrolyte membrane 13 from the substrate B, and the total amount of the exuded liquid LR recovered in the measuring device 62 is measured. The measurement result of the amount of liquid transferred is recorded in the control unit 64.

[0030] In step S5, the control unit 64 determines whether the integrated current amount is equal to or greater than a predetermined amount. If the integrated current amount is equal to or greater than the predetermined amount (YES), it can be determined that the amount of metal ions contained in the plating solution L contained in the supply tank 58 has decreased and that the metal ion concentration in the plating solution L has reached the lower limit of the metal ion concentration at which a film can be formed. In this case, the process proceeds to step S6. On the other hand, if the integrated current amount is less than the predetermined value (NO), it can be determined that the amount of metal ions contained in the plating solution L contained in the supply tank 58 is sufficient, and therefore the metal ion concentration in the plating solution L is sufficient to form a film. In this case, the process returns to step S2, where a new substrate B is placed on the mounting table 40 and a metal coating F is formed on the new substrate B.

[0031] In step S6, the supply liquid LS, adjusted to a metal ion concentration higher than that of the plating solution L before film formation in step S1, is supplied to the supply tank 58 by the total liquid volume. For example, the supply liquid LS may be prepared in advance, with a metal ion concentration corresponding to the saturation solubility at the temperature of the plating solution L. In step S6 of FIG. 2, unlike the supply device 80 shown in FIG. 1, the supply liquid LS adjusted to such a metal ion concentration is prepared in advance, and the total liquid volume is supplied to the supply tank 58 via a pump (not shown) of the supply device 80. In this way, the control unit 64 controls the supply device 80 to supply the supply liquid LS to the supply tank 58 when the integrated current amount reaches a preset amount. Next, in step S7, the plating solution L is circulated by the circulation mechanism 50. This allows the plating solution L to be agitated.

[0032] In this way, the supply tank 58 can be replenished with the replenishment liquid LS adjusted to a metal ion concentration higher than that of the plating solution L before film formation so that the metal ion concentration of the plating solution L contained in the supply tank 58 after film formation approaches the metal ion concentration of the plating solution L contained in the supply tank 58 before film formation. Since the replenishment liquid LS already contains a metal salt derived from the metal ion (for example, copper sulfate powder when the metal ion is copper ion) dissolved therein, it is not necessary to dissolve the metal salt in the plating solution L, and therefore film formation can be carried out quickly. Furthermore, film formation defects caused by the metal salt entering the container 15 during film formation can be prevented. Furthermore, since the replenishment liquid LS supplied to the supply tank 58 is circulated as part of the plating solution L, the metal ion concentration of the plating solution L can be made uniform.

[0033] Unlike the flow shown in FIG. 2, a metal film may be formed according to the flow shown in FIG. 3. In this flow, steps S61 and S62 shown in FIG. 3 are performed instead of step S6 shown in FIG. 2. Specifically, in step S61, the metal ion concentration of the replenishment liquid LS is adjusted by the above-described raw liquid storage section 81 and solvent storage section 82 based on the total liquid volume and integrated current amount calculated by the control section 64. The adjusted metal ion concentration of the replenishment liquid LS is higher than the metal ion concentration of the plating solution L before film formation in step S1. In addition, the replenishment liquid LS is a replenishment liquid whose metal ion concentration has been adjusted by replenishment to the plating solution L so that the metal ion concentration of the plating solution contained in the supply tank 58 after film formation at the time of step S61 matches the metal ion concentration of the plating solution L contained in the supply tank 58 before film formation in step S1.

[0034] Next, in step S62, the replenishing device 80 supplies the total amount of the replenishment liquid adjusted in step S61 to the supply tank 58. This allows the replenishing liquid LS, the metal ion concentration of which has been adjusted in accordance with the amount of metal ions consumed among the metal ions contained in the plating solution L and the amount (weight or volume) of the leached solution LR, to be supplied to the replenishing device 80. As a result, the metal ion concentration of the plating solution L contained in the supply tank 58 after film formation can be made to accurately approach the metal ion concentration of the plating solution L contained in the supply tank 58 before film formation.

[0035] Generally, when forming a metal film F using the film forming apparatus 1 shown in FIG. 1, the amount of metal ions consumed in one film formation is small, making it difficult to directly detect changes in the metal ion concentration of the plating solution L contained in the supply tank 58 using an ion concentration meter. However, in the flow shown in FIG. 3, steps S61 and S62 allow the supply tank 58 to be replenished with the replenishing solution LS, the metal ion concentration of which has been adjusted, and therefore the metal ion concentration of the plating solution L contained in the supply tank 58 can be accurately controlled. As a result, a metal film F of consistent quality can be formed.

[0036] Furthermore, in the flow shown in FIG. 2, the integrated current amount is measured in steps S4 and S5, and if this integrated current amount is equal to or greater than a predetermined amount, the process proceeds to step S6 to replenish the replenishment liquid. However, for example, as shown in FIG. 4, steps S3 and S5 may be omitted, and the replenishment device 80 may replenish the replenishment liquid LS after each film formation on the substrate B. In this case, the amount of metal ions consumed in each film formation is known in advance, and in step S6, the concentration of the metal ions contained in the replenishment liquid LS can be easily adjusted based on the amount of metal ions consumed and the total amount of leaching liquid. Furthermore, because the replenishment liquid LS is replenished after each film formation, changes in the metal ion concentration of the plating solution L can be minimized, and the metal ion concentration of the plating solution L contained in the supply tank 58 can be accurately controlled.

[0037] [Confirmation test] Using the film-forming apparatus shown in Figure 1(a), a copper film was formed once as a metal film. The plating solution before film formation was a copper sulfate aqueous solution, and the copper ion concentration was 0.6 mol / L. Based on the accumulated current during film formation, the weight of copper consumed was 0.7 g, and the total amount of leached solution was 10 cc. Based on this result, 10 cc of 2.0 mol / L replenishment solution was replenished using the replenishment device. As a result, the copper ion concentration of plating solution L decreased due to film formation, but after replenishment of the replenishment solution, it was confirmed that the copper ion concentration of plating solution L returned to 0.6 mol / L.

[0038] [Example] Using the film-forming apparatus shown in Figure 1(a), copper films were formed 50 times (50 shots) as metal films. Figure 5 shows the change in the ion concentration of the plating solution in the supply tank measured after each film formation. The plating solution before film formation was a copper sulfate aqueous solution, and the copper ion concentration was 1.0 mol / L. Based on the integrated current during each film formation, the weight of copper consumed was 0.7 g, and the total amount of leaching solution was 10 cc. After each film formation, 10 cc of 2.0 mol / L replenishment solution was replenished using the replenishment device. As a result, the copper ion concentration of plating solution L decreased during film formation, but increased with each replenishment of replenishment solution. As a result, the copper ion concentration of plating solution L after 50 film formations was 0.976 mol / L. Therefore, the decrease in copper ion concentration in plating solution L was approximately 2.4%, which means that the decrease in copper ion concentration was suppressed. Therefore, by replenishing the plating solution with such a replenisher, it is possible to stably deposit metal films on multiple substrates in succession. Without replenishing the plating solution with a replenisher, the copper ion concentration in the plating solution L after 50 film depositions was 0.90 mol / L, and the decrease in copper ion concentration was significant. [Explanation of symbols]

[0039] 1: film forming device, 15: container, 13: electrolyte membrane, 50: circulation mechanism, 58: supply tank, 60: measuring device, 80: replenishing device, L: plating solution, LS: replenishing solution, LR: seepage solution

Claims

1. A film formation apparatus comprising: an anode; a container that contains a plating solution; and an electrolyte membrane that covers an opening of the container formed at a position opposite the anode, thereby sealing the plating solution in the container; and the apparatus forms a metal coating on a substrate in contact with the electrolyte membrane by electrolytic plating, a supply tank for supplying the plating solution to the container; a circulation mechanism that circulates the plating solution between the supply tank and the container; a measuring device for measuring the total amount of exuded liquid that exudes from the electrolyte membrane during membrane formation due to the plating solution in the container; a replenishing device that replenishing the supply tank with a liquid amount corresponding to the total liquid amount, The replenishing device is characterized in that it replenishes the supply tank with the replenishing liquid adjusted to a metal ion concentration higher than the metal ion concentration of the plating solution before film formation, so that the metal ion concentration of the plating solution contained in the supply tank after film formation approaches the metal ion concentration of the plating solution contained in the supply tank before film formation by replenishment of the replenishing liquid.

2. the film-forming apparatus sequentially forms films on the plurality of substrates, the measuring device measures an integrated amount of current passed through the anode and the substrate during deposition of the metal coating; 2. The metal coating forming apparatus according to claim 1, wherein the supply device adjusts the concentration of the metal ions in the supply solution based on the accumulated current amount and the total amount of solution, and supplies the adjusted supply solution to the supply tank.

3. the measuring device measures an integrated amount of current passed through the anode and the substrate during deposition of the metal coating; 2. The metal coating deposition apparatus according to claim 1, wherein the replenishing device supplies the replenishment solution to the supply tank at a timing when the integrated current amount reaches a preset amount.

4. 2. The metal coating deposition apparatus according to claim 1, wherein the replenishing device refills the replenishment liquid every time a film is deposited on the substrate.

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