Metal film deposition equipment

Abstract

To provide a metal film forming apparatus that can suppress the occurrence of defective film formation of a metal film.SOLUTION: The anode 11 of a metal film forming apparatus 1 of the invention is made of the same metal as the metal film and is soluble in a plating solution L. The film forming apparatus 1 further includes: an adjusting device 73 that adjusts the inter-electrode distance between a base material (cathode) W in contact with an electrolyte membrane 13 and the anode 11 by moving the anode 11 with respect to a container 15; and a control device 60 that controls the amount of movement of the anode 11 by the adjustment device 73. The control device 60 includes: an inter-electrode distance estimation unit 64 for estimating the inter-electrode distance D between the base material and the anode 11 at the time of film formation; a movement amount calculation unit 65 that calculates the movement amount of the anode 11 from the estimated inter-pole distance D so that the inter-pole distance D falls within a predetermined range; and an adjustment execution unit 66 that controls the adjustment device 73 so that the anode 11 moves by the movement amount.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] As an example of this type of technology, Patent Document 1 proposes a film formation apparatus for forming a metal film on the surface of a substrate. This film formation apparatus includes an anode, an electrolyte membrane disposed between the anode and the substrate (cathode), and a power supply unit for applying a voltage between the anode and the substrate. The film formation apparatus further includes a container for containing a plating solution between the anode and the electrolyte membrane so as to be in contact with them. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-169399 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the film forming apparatus shown in Patent Document 1, if the anode is made of the same metal as the metal film and is soluble in the plating solution, the anode will be consumed depending on the number of times the metal film is formed. This consumption of the anode increases the inter-electrode distance between the anode and the cathode (substrate). This causes current concentration at the end of the cathode and an increase in diffusion resistance for ion supply due to dissolution of the anode, making it impossible to form a homogeneous metal film, and it is expected that this will result in poor formation of the metal film.

[0005] The present invention has been made in consideration of the above-mentioned points, and an object of the present invention is to provide a metal film forming apparatus that can suppress the occurrence of defective formation of a metal film. [Means for solving the problem]

[0006] In consideration of the above problems, a metal film forming apparatus according to the present invention includes at least an anode, an electrolyte membrane disposed between a substrate having the anode and a cathode, a container that contains the anode and a plating solution and has an opening on the substrate side sealed with the electrolyte membrane, and a power supply unit that applies a voltage between the anode and the cathode, and forms a metal film derived from metal ions in the plating solution on a surface of the substrate by applying the voltage with the electrolyte membrane in contact with the cathode, and the anode is made of the same metal as the metal film and is soluble in the plating solution. The film formation apparatus further includes an adjustment device that adjusts the inter-electrode distance between the cathode and the anode in contact with the electrolyte membrane by moving the anode relative to the container, and a control device that controls the amount of movement of the anode by the adjustment device, and the control device includes an inter-electrode distance estimation unit that estimates the inter-electrode distance between the cathode and the anode during film formation, a movement amount calculation unit that calculates the movement amount of the anode from the estimated inter-electrode distance so that the inter-electrode distance falls within a predetermined range, and an adjustment execution unit that controls the adjustment device so that the anode moves by the movement amount.

[0007] According to the present invention, when a voltage is applied between the anode and the substrate in a state where the electrolyte membrane is in contact with the substrate during film formation, metal ions in the plating solution in the container migrate to the substrate side via the electrolyte membrane. When electrons are donated to the metal ions from the surface of the substrate, metal derived from the metal ions in the plating solution is precipitated on the surface of the substrate, and a metal coating made of the precipitated metal can be formed on the surface of the substrate.

[0008] Here, since the anode is a soluble anode, the metal constituting the anode dissolves in the plating solution during film formation, and the metal of the anode is consumed as the metal film is formed. As a result, the thickness of the anode decreases, and the inter-electrode distance between the anode and the substrate increases. Therefore, according to the present invention, the control device estimates the inter-electrode distance between the cathode and the anode during film formation, calculates the amount of movement of the anode so that the inter-electrode distance falls within a predetermined range, and controls the adjustment device to move the anode closer to the cathode by the calculated amount of movement. As a result, the inter-electrode distance between the anode and the cathode can be kept within a predetermined range, so that the current can be stably passed from the anode to the cathode and the diffusion of the metal ions dissolved from the anode can also be stabilized. As a result, the metal film can be stably formed.

[0009] In a preferred embodiment, the electrode gap estimation unit calculates an integrated current amount, which is integrated over time from the value of a current passed from the anode to the substrate when a voltage is applied by the power supply unit, and estimates the electrode gap based on the integrated current amount.

[0010] According to this aspect, the consumption of the anode corresponds to the integrated current amount accumulated over time, so it is possible to estimate the inter-electrode distance between the anode and the cathode without directly measuring the consumption of the anode, for example by measuring the thickness of the anode.

[0011] Furthermore, in another preferred aspect, the film forming apparatus further includes a displacement meter that measures the amount of displacement of the opposing surface of the anode facing the cathode based on a specific position of the container, and the electrode distance estimation unit estimates the electrode distance based on the amount of displacement.

[0012] According to this aspect, by using a displacement meter to measure the amount of displacement of the opposing surface of the anode facing the cathode, the reduction in thickness of the opposing surface of the anode can be directly detected, and the inter-electrode distance between the anode and the cathode can be more accurately estimated. Effect of the Invention

[0013] According to the present invention, the occurrence of defective film formation of a metal film can be suppressed. [Brief description of the drawings]

[0014] [Figure 1] 1 is a schematic cross-sectional view of a metal film forming apparatus according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a control block diagram of the control device shown in FIG. [Diagram 3] FIG. 2 is a schematic cross-sectional view of the film forming apparatus shown in FIG. 1, illustrating a state during film formation. [Figure 4] FIG. 2 is a control flow diagram of the film forming apparatus shown in FIG. [Diagram 5] FIG. 13 is a diagram showing the relationship between the integrated current amount and the electrode distance. [Figure 6] FIG. 5 is a schematic cross-sectional view of a metal film forming apparatus according to a second embodiment of the present invention. [Figure 7] FIG. 7 is a schematic cross-sectional view of the film forming apparatus shown in FIG. 6, illustrating a state during film formation. [Figure 8] 1 is a graph showing the relationship between the thickness (thickness ratio) of an anode measured using a laser displacement meter and a micrometer and the number of treatments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, a metal film forming apparatus according to an embodiment of the present invention will be described with reference to the drawings.

[0016] First Embodiment Fig. 1 is a schematic cross-sectional view of a metal coating deposition apparatus 1 according to a first embodiment of the present invention. Fig. 2 is a control block diagram of the control device shown in Fig. 1, and Fig. 3 is a schematic cross-sectional view of the deposition apparatus shown in Fig. 1, showing a state during deposition.

[0017] 1 and 3, the film forming apparatus 1 includes an anode 11, an electrolyte membrane 13 disposed between the anode 11 and a substrate W, and a container 15 that contains the anode 11 and a plating solution L and has an opening 15g that opens to the substrate W side sealed with the electrolyte membrane 13. The film forming apparatus 1 further includes a power supply unit 19 that applies a voltage between the anode 11 and the substrate W that serves as a cathode, and may further include a mounting table 20 on which the substrate W is placed, and a lifting device 70, as necessary.

[0018] The film forming apparatus 1 is an apparatus for forming a metal coating on the surface wa of the substrate W by applying a voltage between the anode 11 and the substrate W by a power supply unit 19 with an electrolyte membrane 13 in contact with the substrate W placed on a mounting table 20. During film formation, metal ions contained inside the electrolyte membrane 13 from the plating solution L are reduced on the surface wa of the substrate W, and metal derived from the metal ions is precipitated, and the precipitated metal forms a metal coating.

[0019] The substrate W functions as a cathode. The material of the substrate W is not particularly limited as long as it functions as a cathode (i.e., a surface having electrical conductivity), and may be made of a metal material such as aluminum or iron, or may be a resin, ceramic, or the like, coated with a metal layer such as copper, nickel, silver, or iron. In this embodiment, the surface wa of the substrate W that faces the anode 11 and to which a voltage is applied by the power supply unit 19 between the anode 11 and the anode 11 is the cathode. For example, when a metal coating is formed on the entire surface wa of the substrate W, this surface is the cathode, and the interelectrode distance D refers to the distance between the surface of the anode 11 and the surface wa of the substrate W that faces the anode 11.

[0020] The mounting table 20 is made of a conductive material and is disposed below the container 15 so that the substrate W faces the electrolyte membrane 13. The substrate (specifically, the cathode) W is electrically connected to the negative electrode of the power supply unit 19 via the mounting table 20. When the mounting table 20 is made of an insulating material, the negative electrode of the power supply unit 19 may be directly connected to the substrate W via a wire.

[0021] The anode 11 has a shape corresponding to the film formation region of the substrate W. The film formation region of the substrate W means the portion of the surface wa of the substrate W facing the anode 11. The anode 11 is a non-porous (for example, non-porous) anode made of the same metal as the metal coating, and is a block-shaped or flat-plate-shaped anode. The anode 11 is made of the same metal as the metal coating and is soluble in the plating solution L.

[0022] Examples of the material of the anode 11 include copper, nickel, silver, and tin. In this embodiment, the material is not particularly limited as long as the anode 11 dissolves when a voltage is applied using the power supply unit 19. The anode 11 is attached to a container 15 made of, for example, an insulating material, and is electrically connected to the positive electrode of the power supply unit 19.

[0023] As described above, the plating solution L is a solution containing the metal of the metal film to be formed in an ion state, and examples of the metal include copper, nickel, silver, and tin. The plating 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 nickel, examples of the plating solution L include aqueous solutions of nickel nitrate, nickel phosphate, nickel succinate, nickel sulfate, and nickel pyrophosphate. Furthermore, when the metal is copper, examples of the plating solution L include aqueous solutions containing copper sulfate, copper pyrophosphate, and the like.

[0024] The electrolyte membrane (solid electrolyte membrane) 13 is a flexible membrane that can be impregnated (contained) with metal ions by contacting it with the above-mentioned plating solution L. The electrolyte membrane 13 is not particularly limited as long as it can reduce metal ions in the substrate W and precipitate metal derived from the metal ions when a voltage is applied from a power supply unit 19. Examples of the material of the electrolyte membrane 13 include fluorine-based resins such as Nafion (registered trademark) manufactured by DuPont, hydrocarbon-based resins, polyamic acid resins, and resins having an ion exchange function such as Selemion (CMV, CMD, CMF series) manufactured by Asahi Glass Co., Ltd.

[0025] As shown in FIG. 1, the container 15 is made of a material insoluble in the plating solution L, and the anode 11 and the electrolyte membrane 13 are attached to the container 15. Inside the container 15, a storage space S for storing the plating solution L is formed by the side wall of the container 15, the anode 11, and the electrolyte membrane 13. Inside the container 15, the anode 11 is attached, and an opening 15g that opens to the side of the substrate W is formed at a position opposite the anode 11. The opening 15g opens downward, and the electrolyte membrane 13 is attached so as to seal the opening 15g. In this embodiment, the periphery of the electrolyte membrane 13 is attached to the container 15 by being sandwiched between the main body 15a and the frame 15b of the container 15. The anode 11 and the electrolyte membrane 13 are arranged apart from each other and are in a non-contact state, and the storage space S between them is filled with the plating solution L. In this manner, the container 15 has a structure in which the plating solution L contained in the container space S comes into direct contact with the anode 11 and the electrolyte membrane 13.

[0026] Furthermore, the container 15 is formed with a supply flow path 15c for supplying the plating solution L to the storage space S, and a discharge flow path 15d for discharging the plating solution L from the storage space S. The supply flow path 15c and the discharge flow path 15d are holes communicating with the storage space S, and are formed on either side of the storage space S. The film forming apparatus 1 may have a heating device (not shown) upstream of the supply flow path 15c (for example, in the tank T that stores the plating solution L).

[0027] The lifting device 70 lifts and lowers at least one of the container 15 and the mounting table 20 so that the electrolyte membrane 13 and the substrate W can be moved toward and away from each other. In this embodiment, the mounting table 20 is fixed, and the container 15 is lifted and lowered by the lifting device 70. As shown in Figs. 1 and 3, the lifting device 70 is provided on the upper part of the container 15. The lifting device 70 may be a known electric actuator that converts the rotation of a motor such as a servo motor into linear motion. As long as the electrolyte membrane 13 can be moved toward and away from the substrate W by linear motion, the lifting device 70 may be provided on the mounting table 20 or may be a hydraulic or pneumatic cylinder.

[0028] In this embodiment, the main body 71 of the lifting device 70 is fixed to a housing (not shown) that houses the film forming apparatus 1, and a tip portion of a rod 72 that moves linearly with respect to the main body 71 is attached to the container 15. As a result, the container 15 is suspended via the lifting device 70, and the container 15 becomes movable with respect to the mounting table 20.

[0029] In this embodiment, an adjustment device 73 is attached to the rod 72, which adjusts the inter-electrode distance D between the cathode (substrate W) in contact with the electrolyte membrane 13 and the anode 11 by moving the anode 11 relative to the container 15. The adjustment device 73 includes a main body 74 fixed to the rod 72, and a rod 75 that can be extended and retracted by moving linearly relative to the main body 74. The adjustment device 73 has a mechanism similar to that of the lifting device 70, and is, for example, a known electric actuator that converts the rotation of a motor such as a servo motor into linear motion.

[0030] The following describes a circulation mechanism for circulating the plating solution L in the film forming apparatus 1 and the control device 60. The film forming apparatus 1 includes, as the circulation mechanism, a tank 17 connected to the accommodation body 15 for accommodating the plating solution L discharged from the accommodation body 15, and a pump (pressure-feeding device) 18 connected to the tank 17 for pressure-feeding the plating solution L from the tank 17 to the accommodation body. The film forming apparatus 1 further includes a pressure regulating valve 31 between the accommodation body 15 and the tank 17 for regulating the liquid pressure of the plating solution L discharged from the accommodation body 15.

[0031] A path from the tank 17 via the pump 18 to the supply flow path 15c is a supply route 41 that supplies the plating solution L to the container 15. A path from the discharge flow path 15d to the tank 17 via the pressure regulating valve 31 and the filter 51 is a discharge route 42 that discharges the plating solution L to the tank 17.

[0032] A circulation mechanism including a supply route 41 and a discharge route 42 allows plating solution L, the metal ion concentration of which has been adjusted to a predetermined concentration in the tank 17, to be supplied to the storage space S, and the plating solution L used during film formation in the storage space S to be returned to the tank 17.

[0033] The replacement mechanism 53A is a mechanism for replacing the plating solution L contained in the container 15 with the atmosphere, returning the plating solution L contained in the container 15 to the tank 17, and introducing the atmosphere into the container 15. In this embodiment, an air pump 53 for pumping the atmosphere is connected to the supply flow path 15c of the container 15, and the replacement mechanism 53A is composed of the air pump 53 and a pipe connecting the air pump 53 and the supply flow path 15c of the container 15. The atmosphere contained in the container 15 is replaced with the plating solution L by the pump 18. In FIG. 1 and the like, the discharge flow path 15d is formed in the vicinity of the anode 11, so that the majority of the plating solution L in the container space S is pushed out by the flow of the atmosphere. However, by connecting the discharge flow path 15d to the container space S in the vicinity of the electrolyte membrane 13, the majority of the plating solution L in the container space S may be replaced with the atmosphere.

[0034] In this embodiment, the plating solution L is replaced with the atmosphere by providing the air pump 53 in the replacement mechanism 53A. However, the present invention is not limited to this, and for example, a relief valve may be provided in the discharge route, and the plating solution L may be sucked from the container 15 by rotating the pump 18 in the reverse direction, while the atmosphere is introduced through the relief valve. Also, a liquid drain hole may be provided in the container 15 near the electrolyte membrane 13, and the plating solution L may be discharged by its own weight.

[0035] The control device 60 controls the operation of the lifting device 70, the adjustment device 73, the pump 18, and the air pump 53 of the replacement mechanism 53A, and controls the application of power by the power supply unit 19. Although not shown, the control device 60 includes a storage device (not shown) that stores a control program for executing the following series of steps, and a calculation device (not shown) that executes the control program. The storage device further stores set values ​​such as the start-up time of the pump 18 and the air pump 53, the time for applying voltage by the power supply unit 19, and the amount of displacement by the lifting device 70. The control device 60 receives inputs such as a signal from a pressure sensor (not shown) that measures the pressure in the storage space S of the storage body 15 via an input device or the like.

[0036] As shown in FIG. 2, the control device 60 includes, as software, a lift control unit 61, a film formation execution unit 62, a replacement unit 63, a pole distance estimation unit 64, a movement amount calculation unit 65, and an adjustment execution unit 66.

[0037] The lifting / lowering control unit 61 controls the lifting device 70 to lower the container 15, for example, in response to a signal from an input device, after the substrate W is placed on the mounting table 20, and to raise the container 15 after film formation is completed.

[0038] 3, the film formation execution unit 62 applies a voltage from the power supply unit 19 for a time period corresponding to the thickness of the metal film to be formed. In this way, a metal film derived from metal ions in the plating solution L is formed on the surface of the substrate W.

[0039] After the film formation execution unit 62 completes the film formation, the replacing unit 63 controls the lift control unit 61 to drive the air pump 53 so as to replace the plating solution L with the atmosphere before the electrolyte membrane 13 is separated from the substrate W (before the container 15 is raised). In addition, the replacing unit 63 controls the lift control unit 61 to drive the pump 18 so as to replace the atmosphere with the plating solution L after the electrolyte membrane 13 is brought into contact with the substrate W (after the container 15 is lowered) and before the film formation execution unit 62 starts the film formation.

[0040] The electrode distance estimation unit 64 estimates the electrode distance D between the substrate (cathode) W and the anode 11 during film formation. Specifically, the electrode distance estimation unit 64 calculates an integrated current amount integrated over time from the value of a current passed from the anode 11 to the substrate W by applying a voltage from the power supply unit 19, and estimates the electrode distance based on the integrated current amount. Here, the integrated current amount is a value obtained by multiplying the passed current value by the current passing time (seconds).

[0041] Here, as shown in Fig. 5, since the integrated current amount passed from the anode 11 to the substrate W is approximately proportional to the amount of dissolution of the anode 11, the inter-electrode distance D between the substrate W and the anode 11 increases with an increase in the integrated current amount. Therefore, in the early stage of film formation, the inter-electrode distance is in a good range (see, for example, the circle in Fig. 5), but when a predetermined inter-electrode distance is exceeded, the inter-electrode distance changes to a poor range (see, for example, the cross in Fig. 5). In the poor inter-electrode distance range, the inter-electrode distance D between the anode 11 and the substrate W is large, so that the current concentrates at the end of the substrate W, or the diffusion resistance for the supply of metal ions due to the dissolution of the anode 11 increases, making it impossible to form a homogeneous metal film, which may result in poor formation of the metal film.

[0042] From this viewpoint, in this embodiment, the movement amount calculation unit 65 calculates the movement amount of the anode 11 from the estimated electrode distance so that the electrode distance D falls within a predetermined range (good range). Furthermore, the adjustment execution unit 66 controls the adjustment device 73 so that the anode 11 moves in a direction approaching the substrate W by the movement amount calculated by the movement amount calculation unit 65. This makes it possible to maintain the electrode distance D within a good range suitable for film formation, as shown by the ● mark in Fig. 5.

[0043] The control flow will be described below with reference to Fig. 4. First, in step S1, in the state shown in Fig. 1, the electrode distance estimation unit 64 estimates the electrode distance D between the substrate (cathode) W and the anode 11 during film formation. In this embodiment, as described above, the electrode distance estimation unit 64 estimates the electrode distance based on the integrated amount of current passed from the anode 11 to the substrate W. Note that this step S1 may be performed in the state shown in Fig. 3 after film formation.

[0044] Next, the process proceeds to step S2, where it is determined whether the electrode gap D is within a predetermined range. If it is within the predetermined range (if YES), the process proceeds to step S5, where a series of steps for performing film formation, which will be described later, are performed. If the electrode gap D is not within the predetermined range (if NO), the process proceeds to step S3. In step S3, the movement amount calculation unit 65 calculates the movement amount of the anode 11 from the estimated electrode gap so that the electrode gap D falls within a predetermined range (good range), and the process proceeds to step S4. In step S4, the adjustment execution unit 66 moves the anode 11 by the calculated movement amount so as to approach the substrate W. In this way, the metal film can be formed while maintaining a good electrode gap D in the film formation. Note that the value of the integrated current amount is reset between step S3 and step S4.

[0045] Next, in step S5, the elevation control unit 61 lowers the container 15 at a preset stroke, and the electrolyte membrane 13 is brought into contact with the surface wa of the substrate W from above. As a result, the container 15 and the substrate W are arranged as shown in FIG.

[0046] Next, in step S6, the replacement unit 63 drives and controls the pump 18 to supply the plating solution L from the tank 17 to the storage space S of the storage body 15. Since the storage space S is filled with the atmosphere (air) as described later, the atmosphere in the storage body 15 can be replaced with the plating solution L. When the storage body 15 is filled with the plating solution L and the liquid pressure of the plating solution L in the storage space S reaches a predetermined pressure, the plating solution L passes through the pressure regulating valve 31. In this way, the electrolyte membrane 13 can press the substrate W uniformly using the liquid pressure of the plating solution L. Note that the fact that the liquid pressure of the plating solution L in the storage space S has reached the predetermined pressure may be detected by a pressure sensor or may be determined by the passage of a preset time.

[0047] Next, in step S7, while the substrate W is pressed by the electrolyte membrane 13 due to the hydraulic pressure of the plating solution L, the film formation execution unit 62 controls the power supply unit 19 to apply a voltage between the anode 11 and the substrate W for a predetermined time. As a result, the metal ions contained in the electrolyte membrane 13 move to the surface of the substrate W in contact with the electrolyte membrane 13 and are reduced on the surface wa of the substrate W. As a result, metal is precipitated on the surface of the substrate W, and a metal coating having a predetermined thickness is formed on the surface of the substrate W. At this time, since the plating solution L is contained in the containing space S, metal ions can be constantly supplied to the electrolyte membrane 13.

[0048] Next, in step S8, the replacing unit 63 controls the replacing operation of the replacing mechanism 53A so that the plating solution L contained in the container 15 is replaced with air while the electrolyte membrane 13 is in contact with the substrate W. Specifically, the air pump 53 is driven to pump air into the container 15, thereby discharging the plating solution L from the container 15. The discharged plating solution L passes through the pressure regulating valve 31 and is returned to the tank 17.

[0049] Next, in step S9, after the replacement operation with the atmosphere is completed, the lift control unit 61 separates the electrolyte membrane 13 from the substrate W, and in step S10, the substrate W on which the membrane has been formed is replaced with the substrate W before the membrane has been formed, and is placed on the mounting table 20. This series of steps is repeated.

[0050] In this embodiment, since the inter-electrode distance D between the anode 11 and the substrate W (cathode) can be kept within a predetermined range, it is possible to stably pass a current from the anode 11 to the substrate W and also stably diffuse metal ions dissolved from the anode 11. As a result, a metal coating can be stably formed.

[0051] <Second embodiment> FIG. 6 is a schematic cross-sectional view of a film-forming apparatus for forming a metal film according to a second embodiment of the present invention. FIG. 7 is a schematic cross-sectional view of the film-forming apparatus shown in FIG. 6, showing a state during film formation. The film-forming apparatus 1 according to the second embodiment differs from that of the first embodiment in that the electrode distance is estimated using a displacement meter, rather than using an integrated current value. Configurations having the same or similar functions as the film-forming apparatus 1 according to the first embodiment are given the same reference numerals as those of the film-forming apparatus 1 according to the first embodiment, and descriptions thereof are omitted, and only different portions will be described.

[0052] 6 and 7, the film forming apparatus 1 according to the second embodiment further includes a displacement meter 80 that measures the amount of displacement of the opposing surface 11a of the anode 11 opposing the substrate W (cathode) using a specific position of the container 15 as a reference. Here, the specific position of the container 15 that serves as the measurement reference is a specific position between the anode 11 and the electrolyte membrane 13.

[0053] The displacement meter 80 is attached to the tip of a shaft 81, and the shaft 81 is attached to the housing 15 via a seal bearing 91 or the like. A driving device 83 is attached to the base end of the shaft 81. Although illustrated in a simplified manner in Figures 6 and 7, the driving device 83 is a device that moves the shaft 81 in the horizontal direction so that the displacement meter 80 attached to the tip of the shaft 81 moves from a position between the anode 11 and the electrolyte membrane 13 (see Figure 6) to a position outside the gap between them (see Figure 7).

[0054] Examples of the displacement meter 80 include a displacement meter that uses ultrasonic waves to measure the distance to the opposing surface 11a of the anode 11, and a displacement meter that uses laser light such as infrared light to measure the distance to the opposing surface 11a of the anode 11, and the measurement principle is not particularly limited as long as it is possible to measure the distance from the displacement meter 80 to the opposing surface 11a of the anode 11. In addition, the displacement meter 80 may be a displacement meter that uses magnetism or a contact type displacement meter.

[0055] In this embodiment, the control device 60 has an electrode distance estimating unit 64 that estimates the electrode distance D between the anode 11 and the substrate W based on the amount of displacement measured by the displacement meter 80 without using the current integration value. Specifically, the electrode distance estimating unit 64 moves the shaft 81 by the driving device 83 so that the displacement meter 80 is located between the anode 11 and the electrolyte membrane 13 during non-film formation as shown in FIG. 6, and then measures the amount of displacement by the displacement meter 80. However, except for the timing of measuring the amount of displacement, as shown in FIG. 7, the driving device 83 moves the shaft 81 to a position away from between the anode 11 and the electrolyte membrane 13 so as not to affect film formation. The electrode distance D is calculated by adding the distance from the displacement meter 80 to the opposing surface 11a of the anode 11 measured by the displacement meter 80 and the distance from the displacement meter 80 to the substrate W.

[0056] Alternatively, a displacement meter 80 may be placed between the anode 11 and the electrolyte membrane 13, and the displacement meter 80 may be moved via a shaft 81 while measuring the displacement at multiple points on the opposing surface 11a of the anode 11, and the maximum value of the measured displacement may be used to estimate the inter-electrode distance D between the anode 11 and the substrate W.

[0057] According to this embodiment, by using the displacement meter 80 to measure the amount of displacement of the opposing surface 11a of the anode 11 facing the substrate W, the reduction in thickness of the opposing surface 11a side of the anode 11 can be directly detected, and therefore the inter-electrode distance between the anode 11 and the substrate W (cathode) can be more accurately estimated.

[0058] Furthermore, as a modification of the second embodiment, the control device 60 may calculate an integrated current amount integrated over time from the value of the current passed from the anode 11 to the substrate W by applying a voltage from the power supply unit 19, as in the first embodiment, and may measure the displacement amount using the displacement meter 80 when the integrated current amount reaches a predetermined integrated current amount. In this modification, the timing of measurement by the displacement meter 80 is determined based on the integrated current amount, so that the frequency of measurement by the displacement meter 80 can be reduced and the reliability of the device can be ensured.

[0059] The following confirmation test was carried out. A copper block was prepared as a substrate for forming a film on its surface by immersing it in a 10% aqueous sulfuric acid solution for 1 minute. The area of ​​the copper block on which the film was to be formed was 2 cm 2 It is.

[0060] Next, a copper film was formed using the film forming apparatus according to the second embodiment of FIG. 6. A 1M copper sulfate aqueous solution was used as the plating solution, and a copper plate (manufactured by Nikola Co., Ltd.) was used as the anode. As film forming conditions, the temperature of the plating solution was set to room temperature, an electrolyte membrane (manufactured by Gore Japan Co., Ltd.) was attached to the substrate, and a copper film having a thickness of 10 μm was formed for 10 minutes at a plating solution pressure of 0.2 MPa and a current value of 184 mA. This film forming process was performed multiple times. When the number of processes reached a predetermined number, the thickness of the anode was measured from the displacement measured by a laser displacement meter mounted on the film forming apparatus, and the anode was removed from the film forming apparatus and the thickness of the anode was measured with a micrometer. The results are shown in FIG. 8.

[0061] As shown in Figure 8, as the number of film formation processes increases, the anode metal is consumed, and the thickness of the anode decreases. Furthermore, the thickness of the anode calculated from the amount of displacement measured by the laser displacement meter installed in the film formation device was almost the same as the thickness of the anode measured with a micrometer after removing it from the film formation device. From this result, it is believed that the electrode distance can be accurately measured using the displacement meter.

[0062] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various design modifications can be made without departing from the spirit of the present invention as described in the claims. [Explanation of symbols]

[0063] 1: film forming device, 11: anode, 13: electrolyte membrane, 15: container, 15g: opening, 19: power supply unit, 60: control device, 64: electrode distance estimation unit, 65: movement amount calculation unit, 66: adjustment execution unit, 73: adjustment device, 80: displacement meter, D: electrode distance, L: plating solution, W: substrate (cathode)

Claims

1. a container that contains the anode and a plating solution and has an opening on the substrate side sealed with the electrolyte membrane; and a power supply unit that applies a voltage between the anode and the cathode, and the film forming device forms a metal film derived from metal ions in the plating solution on a surface of the substrate by applying the voltage with the electrolyte membrane in contact with the cathode, the anode is made of the same metal as the metal coating and is soluble in the plating solution; the film forming apparatus further includes an adjustment device that adjusts an inter-electrode distance between the cathode and the anode in contact with the electrolyte membrane by moving the anode with respect to the container, and a control device that controls an amount of movement of the anode by the adjustment device, The control device includes an electrode distance estimation unit that estimates an electrode distance between the cathode and the anode during film formation; a movement amount calculation unit that calculates a movement amount of the anode from the estimated inter-electrode distance so that the inter-electrode distance falls within a predetermined range; and an adjustment execution unit that controls the adjustment device so that the anode moves by the movement amount.

2. 2. The metal coating deposition apparatus according to claim 1, wherein the electrode distance estimation unit calculates an integrated current amount, which is integrated over time from a current value passed from the anode to the substrate by application of a voltage by the power supply unit, and estimates the electrode distance based on the integrated current amount.

3. the film forming apparatus further includes a displacement meter for measuring a displacement amount of a facing surface of the anode facing the cathode with respect to a specific position of the container; 2. The metal film forming apparatus according to claim 1, wherein the electrode distance estimating unit estimates the electrode distance based on the amount of displacement.

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