JP6699604B2 - Method for forming metal film - Google Patents

Description

  The present invention relates to a method for forming a metal film, which forms a metal film made of a metal of a metal solution on the surface of a substrate using a solid electrolyte membrane.

  Conventionally, the surface of the substrate is applied by applying a voltage to the anode and the cathode in a state where the substrate is in contact with the solid electrolyte membrane between the anode and the substrate which is disposed above the anode and corresponds to the cathode. A method of forming a metal film on a substrate is used.

  As such a technique, for example, in Patent Document 1, a substrate is disposed below an anode via a solid electrolyte membrane, and a voltage is applied between the anode and the substrate, whereby a metal film is formed on the surface of the substrate. A film forming method for forming a film is disclosed. In this film-forming method, a film-forming apparatus provided with a solution container for containing a metal solution containing metal ions is used so that the metal solution comes into contact with both the anode and the solid electrolyte membrane disposed therebelow. .

  During film formation, when a voltage is applied between the anode and the substrate, the metal ions contained in the metal solution contained in the solution container move in the solid electrolyte membrane in the direction from the anode to the substrate, Reduced on the surface. Thereby, a metal film can be formed on the surface of the substrate.

JP, 2014-051701, A

  However, in the film forming method disclosed in Patent Document 1, when the solid electrolyte film is replaced after the metal film is formed, the solid electrolyte film is arranged below the anode. , It flows down from the solution container and leaks.

  In view of such a point, for example, as shown in FIG. 5, if the solid electrolyte membrane 13 is arranged above the anode 11 and a chamber (solution accommodating portion) 15 for accommodating the metal solution L is provided together with the anode 11. Despite the removal of the solid electrolyte membrane 13, it is possible to maintain the state in which the metal solution L is contained in the chamber 15.

  However, if such a structure is adopted, for example, as shown in FIG. 5, the solid electrolyte membrane 13 is recessed downward due to the surface tension of the metal solution L, and the substrate B is contacted from above the solid electrolyte membrane 13. However, a gap S is formed between the substrate B and the solid electrolyte membrane 13. In this state, even if a voltage is applied between the anode 11 and the substrate B by the power supply unit 14 to form a metal film on the surface of the substrate B, the portion of the surface of the substrate B where the gap S is formed is not formed. Since air is trapped, it obstructs the flow of metal ions. As a result, the metal film may not be formed and the metal film may not be formed uniformly.

  The present invention has been made in view of such a point, and an object thereof is to uniformly form a metal film on the surface of the substrate even when the substrate is contacted from above the solid electrolyte membrane. It is to provide a method for forming a metal film that can be formed.

  In view of the above problems, the method for forming a metal film according to the present invention is a solid electrolyte such that an anode and a substrate disposed above the anode and corresponding to a cathode are in contact with the surface of the substrate. A voltage is applied between the anode and the substrate in a state where the membrane is placed and a metal solution containing metal ions is placed between them so as to contact the solid electrolyte membrane and the anode. By doing so, a metal film forming method for forming a metal film made of the metal of the metal solution on the surface of the substrate.

  In the film forming method, the metal film is formed by using a solution storage unit that stores the metal solution so that the metal solution contacts the anode and the solid electrolyte membrane disposed above the anode. To do.

  In the film forming method, the solid electrolyte membrane is arranged between the anode and the substrate, and the accommodation space in which the metal solution of the solution accommodating portion is accommodated is sealed with the solid electrolyte membrane, and the solution accommodation is performed. Liquid supply step of supplying the metal solution to the portion, and after the liquid supply step, by pressurizing the metal solution stored in the solution storage portion, the solid electrolyte membrane bulges upward from the center of the solid electrolyte membrane. As described above, a membrane deforming step of deforming the solid electrolyte membrane into a convex shape, and the solid electrolyte membrane deformed into a convex shape after the membrane deforming step presses the surface of the substrate from above the solid electrolyte membrane. And a film forming step of forming the metal film by applying a voltage between the anode and the substrate after the pressing step.

  According to the method for forming a metal film according to the present invention, a metal film is formed on the surface of a substrate while pressing the surface of the substrate from above the solid electrolyte film, on the solid electrolyte film deformed into a convex shape. Therefore, the metal film can be uniformly formed on the surface of the substrate.

FIG. 3 is a schematic cross-sectional view for explaining the method of forming a metal film according to the first embodiment of the present invention. It is a flow figure for explaining the method of forming the metal membrane concerning a 1st embodiment. It is a typical sectional view for explaining the method of forming the metal membrane concerning a 2nd embodiment of the present invention. It is a flow figure for explaining the film forming method of the metal film concerning a 2nd embodiment. FIG. 3 is a schematic cross-sectional view for explaining a method for forming a metal film, which is a comparison with the first embodiment of the present invention.

  Hereinafter, a method for forming a metal film according to the first and second embodiments of the present invention will be described with reference to FIGS.

1. Metal Film Forming Apparatus 1 First, the metal film forming apparatus 1 will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view for explaining the method for forming a metal film according to the first embodiment of the present invention, and is a view showing a state immediately before a pressing step S3 described later.

  As shown in FIG. 1, the film forming apparatus 1 according to the present embodiment is an apparatus for depositing a metal from metal ions and forming a metal coating film of the deposited metal on the surface of the substrate B. Here, the substrate B includes a substrate made of a metal material such as aluminum, a substrate in which a metal underlayer is formed on a processed surface of a resin or a silicon substrate, or a semiconductor substrate (diode) in which a current flows in one direction. be able to.

  The film forming apparatus 1 includes a metal anode 11, a solid electrolyte membrane 13 arranged between the anode 11 and a substrate B serving as a cathode, and a voltage applied between the anode 11 and the substrate B. And a power supply unit 14 for applying the voltage.

  The anode 11 is electrically connected to the positive electrode of the power supply unit 14 via a chamber (solution storage unit) 15, and the substrate B serving as the cathode is, for example, via a holding jig 17 made of a conductive material, It is electrically connected to the negative electrode of the power supply unit 14. The chamber 15 is made of a material insoluble in the metal solution L described later. The holding jig 17 has a structure capable of holding the substrate B.

  Examples of the anode 11 include ruthenium oxide, platinum, and iridium oxide which are insoluble in the metal solution L, and may be an anode in which these metals are coated on a copper plate or the like. In the present embodiment, the anode 11 may be a soluble anode made of the same metal as the metal of the metal film (metal of the metal ion of the metal solution L).

  The solid electrolyte membrane 13 can be impregnated with metal ions inside by contacting the metal solution L described above, and a metal derived from metal ions can be deposited on the surface of the substrate B when a voltage is applied. If so, it is not particularly limited. As the material of the solid electrolyte membrane, for example, fluorine-based resin such as Nafion (registered trademark) manufactured by DuPont, hydrocarbon-based resin, polyamic acid resin, ion exchange such as selemion (CMV, CMD, CMF series) manufactured by Asahi Glass Co., Ltd. The resin which has a function can be mentioned.

  In the present embodiment, the chamber (solution storage unit) 15 stores the metal solution L, and the storage space G for storing the metal solution L is formed inside thereof. The metal solution L can be, for example, an electrolytic solution containing ions of copper, nickel, silver, or the like. In the metal solution L, a metal to be a metal film exists in an ionic state.

  The anode 11 is arranged in the accommodation space G for accommodating the metal solution L, and an opening 15a having the same size as or larger than the surface of the anode 11 is formed above the chamber 15. The solid electrolyte membrane 13 is arranged in the opening 15a so as to cover it. Specifically, the solid electrolyte membrane 13 is attached to the chamber 15 to such an extent that the opening 15a can be sealed under the action of the liquid pressure of the metal solution L pressurized by the pressure device 19 described later. There is.

  In the present embodiment, the film forming apparatus 1 includes a pressurizing device 19 that pressurizes the metal solution L contained in the chamber 15. The pressurizing device 19 may include a pump, a piston, and the like. The pressurizing device 19 not only supplies the metal solution L into the chamber 15 but also pressurizes the metal solution L contained in the chamber 15, so that the solid electrolyte membrane 13 rises upward from the center of the solid electrolyte membrane 13. As described above, the solid electrolyte membrane 13 can be deformed into a convex shape.

  In this way, the solid electrolyte membrane 13 is arranged between the anode 11 and the substrate B arranged above the anode 11 and corresponding to the cathode so that the surface of the substrate B is in contact with the solid electrolyte membrane 13. The metal solution L can be disposed between them so as to come into contact with the anode 11. Then, the substrate B can be pressed against the solid electrolyte membrane 13, a voltage can be applied between the anode 11 and the substrate B, and a metal film made of the metal of the metal solution L can be formed on the surface of the substrate B. The method for forming the metal film will be briefly described below.

2. Regarding Method of Forming Metal Film: Hereinafter, a method of forming a metal film according to this embodiment will be described with reference to FIG. FIG. 2 is a flow chart for explaining the metal film forming method according to the present embodiment. In this film forming method, first, as shown in FIG. 2, a liquid supply step S1 is performed. In the liquid supply step S1, the solid electrolyte membrane 13 is arranged between the anode 11 and the substrate B, and the metal solution L is supplied to the chamber 15.

  Specifically, the opening 15a of the chamber 15 is covered with the solid electrolyte membrane 13, and the opening 15a is sealed with the solid electrolyte membrane 13. Thereby, the accommodation space G of the chamber 15 in which the metal solution L is accommodated can be sealed with the solid electrolyte membrane 13. In the present embodiment, the metal solution L is supplied after the solid electrolyte membrane 13 is arranged, but the order may be reversed, or these may be carried out simultaneously.

  Next, the pressure device 19 is used to supply the metal solution L from the tank (not shown) to the accommodation space G of the chamber 15. Specifically, the storage space G is filled with the metal solution L while the air in the storage space G is discharged from the exhaust port (not shown) of the chamber 15.

  Next, the film deformation step S2 is performed. In the membrane deforming step S2, after the liquid supplying step S1, the metal solution L contained in the chamber 15 is pressurized by the pressurizing device 19 so that the solid electrolyte membrane 13 rises upward from the center of the solid electrolyte membrane 13. Then, the solid electrolyte membrane 13 is deformed into a convex shape. Specifically, the solid electrolyte membrane 13 is swollen upward by the liquid pressure of the metal solution L. The liquid pressure of the metal solution L is preferably 100 kPa or less so that the solid electrolyte membrane 13 is greatly expanded and is not damaged. The liquid pressure can be measured by the pressure gauge 18 shown in FIG.

  Next, the pressing step S3 is performed. In the pressing step S3, after the film deforming step S2, the surface of the substrate B is pressed against the solid electrolyte membrane 13 deformed into a convex shape from above the solid electrolyte membrane 13. Specifically, the surface of the substrate B is pressed against the solid electrolyte membrane 13 from above to below the solid electrolyte membrane 13 via a holding jig 17 attached to a lifting device (not shown).

  As a result, the center of the substrate B comes into contact with the center of the convex solid electrolyte membrane 13, and as the pressing force increases, the edge from the center of the substrate B gradually comes into contact with the edge from the center of the solid electrolyte membrane 13. To do. As a result, the surface of the substrate B can be brought into contact with the solid electrolyte membrane 13 while pushing out the air existing between them from the center of the substrate B toward the edge of the solid electrolyte membrane 13 and the substrate B. It is possible to suppress the trapping of air between and.

  When the solid electrolyte membrane 13 has wrinkles, the wrinkles formed on the solid electrolyte membrane 13 are stretched so that the surface of the substrate B can be brought into uniform contact with the solid electrolyte membrane 13. In addition, after the surface of the substrate B is completely in contact with the solid electrolyte membrane 13, the surface of the substrate B may be further pressed against the solid electrolyte membrane 13 with a pressure that is a film forming condition.

  Next, the film forming step S4 is performed. In the film forming step S4, a metal film is formed by applying a voltage between the anode 11 and the substrate B after the pressing step S3. When a voltage is applied between the anode 11 and the substrate B, the metal ions of the metal solution L housed in the chamber 15 flow through the solid electrolyte membrane 13 from the anode 11 toward the substrate B, and the surface of the substrate B , This is reduced and metal is deposited. Thereby, a metal film can be formed on the surface of the substrate B.

  According to this embodiment, in the pressing step S3, the surface of the substrate B can be brought into uniform contact with the solid electrolyte membrane 13 while suppressing the entrapment of air between the solid electrolyte membrane 13 and the substrate B. Therefore, the metal film can be uniformly formed on the surface of the substrate B without hindering the movement of the metal ions flowing through the solid electrolyte membrane 13.

[Second Embodiment]
The method for forming a metal film according to the second embodiment of the present invention will be described below. FIG. 3 is a schematic cross-sectional view for explaining the method for forming a metal film according to the second embodiment of the present invention, and FIG. 4 illustrates the method for forming a metal film according to the second embodiment. FIG. Note that FIG. 3 is a schematic cross-sectional view in the damage determination step S21 shown in FIG.

  The film forming method according to the present embodiment is different from the film forming method according to the first embodiment in that the sensor 16 detects a bulge of the solid electrolyte membrane 13 and determines damage to the solid electrolyte membrane 13 Damage determination The difference is that step S21 is further added. Since the other steps are the same, detailed description will be omitted.

  In the present embodiment, the film forming apparatus 1 includes a sensor 16 that detects a bulge of the solid electrolyte membrane 13. The sensor 16 detects a bulge of the solid electrolyte membrane 13 when the solid electrolyte membrane 13 is deformed into a convex shape, or detects the amount of the bulge by using light rays such as infrared rays or laser light.

  In the film forming method of the present embodiment, after the membrane deforming step S2, a damage determining step S21 for determining damage to the solid electrolyte membrane 13 is performed. Specifically, in the damage determination step S21, if the sensor 16 detects a bulge of the solid electrolyte membrane 13 after the membrane deformation step S2, or if the bulge amount is within a predetermined range, the solid electrolyte membrane 13 is damaged. If it is determined that there is no pressure, the process proceeds to the pressing step S3.

  On the other hand, in the damage determination step S21, when the bulge of the solid electrolyte membrane 13 cannot be detected or the bulge amount is smaller than the predetermined range, it is determined that the solid electrolyte membrane 13 is damaged, and the metal solution L is solid electrolyte membrane. It can be estimated that it is leaking from 13. In this case, the pressurization by the pressurizing device 19 is stopped, the liquid pressure of the metal solution L is reduced, and the solid electrolyte membrane 13 is replaced. As a result, it is possible to prevent the excess metal solution from leaking due to further damage to the solid electrolyte membrane 13.

  Although the embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and there are design changes and the like within a range not departing from the gist of the present invention. However, they are included in the present invention.

  In the second embodiment, the sensor measures the amount of swelling of the solid electrolyte membrane and determines the damage to the solid electrolyte membrane. However, the sensor measures the amount of swelling of the solid electrolyte membrane, and the sensor measures the amount of swelling of the solid electrolyte membrane. Life may be predicted.

  1: film forming device, 11: anode, 13: solid electrolyte membrane, 14: power supply part, 15 chamber (solution processing part), 19: pressurizing device

Claims (1)

A solid electrolyte membrane is arranged between the anode and a substrate which is arranged above the anode and corresponds to the cathode so that the surface of the substrate is in contact, and is in contact with the solid electrolyte membrane and the anode. As described above, in the state in which a metal solution containing metal ions is arranged between them, a voltage is applied between the anode and the substrate to form a metal coating of the metal of the metal solution on the surface of the substrate. A method of depositing a metal coating on
In the film forming method, the metal film is formed by using a solution storage unit that stores the metal solution so that the metal solution contacts the anode and the solid electrolyte membrane disposed above the anode. Is what
In the film forming method, the solid electrolyte membrane is arranged between the anode and the substrate, and the accommodation space in which the metal solution of the solution accommodating portion is accommodated is sealed with the solid electrolyte membrane, and the solution accommodation is performed. A liquid supply step of supplying the metal solution to the part,
After the liquid supply step, by pressing the metal solution stored in the solution storage unit, the solid electrolyte membrane is deformed into a convex shape so that the solid electrolyte membrane bulges upward from the center of the solid electrolyte membrane. A film deformation step to
After the membrane deforming step, to the solid electrolyte membrane deformed into a convex shape, from above the solid electrolyte membrane, a pressing step of pressing the surface of the substrate,
After the pressing step, at least a film forming step of forming the metal film by applying a voltage between the anode and the substrate is included.

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