JP6699606B2 - Metal film forming equipment - Google Patents

Description

  The present invention relates to a metal film forming apparatus for forming a metal film on the surface of a substrate by bringing the solid electrolyte film into contact with the surface of the substrate.

  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 film forming apparatus for forming a metal film on a substrate is used.

  As such a technique, for example, Patent Document 1 proposes the following film forming apparatus. This film forming apparatus includes an anode, a solid electrolyte membrane arranged below the anode between the anode and a substrate, a solution containing section for containing a metal solution so as to contact the solid electrolyte membrane and the anode, and an anode. And a power supply unit for applying a voltage between the substrate and the substrate.

  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. Further, during film formation, oxygen gas is generated from the metal solution, and this oxygen gas may float in the metal solution due to buoyancy and adhere to the anode. As a result, at the time of film formation, the portion to which the oxygen gas attached to the anode is attached is electrically insulated, which may cause a film formation failure.

  In view of such a point, for example, by disposing the solid electrolyte membrane above the anode and providing a chamber (solution accommodating portion) for accommodating the metal solution together with the anode, the metal solution is removed regardless of the removal of the solid electrolyte membrane. Can be held in the chamber. Thereby, liquid leakage of the metal solution at the time of replacement of the solid electrolyte membrane can be reduced.

  However, even if such a structure is adopted, the gas generated from the anode below the solid electrolyte membrane floats in the metal solution and adheres to the solid electrolyte membrane. As a result, the movement of metal ions is hindered in the solid electrolyte membrane, which may lead to defective film formation.

  The present invention has been made in view of such a point, and the purpose thereof is to suppress the adhesion of bubbles in the metal solution to the solid electrolyte membrane, whereby the metal ions in the solid electrolyte membrane are suppressed. An object of the present invention is to provide a film forming apparatus for a metal film, which can prevent the movement of the metal film from being hindered and can avoid a defect in forming the metal film.

  In view of the above problems, the apparatus for depositing a metal film according to the present invention includes an anode, the anode, and a substrate corresponding to the cathode so that the surface of the substrate is in contact with the substrate above the anode. Between the disposed solid electrolyte membrane, the solution storage part in which a storage space for storing a metal solution containing metal ions is formed so as to come into contact with the solid electrolyte membrane and the anode, and between the anode and the substrate. A power supply unit for applying a voltage, and a film forming apparatus for forming a metal film, wherein the film forming apparatus supplies the metal solution to the accommodation space, and the metal solution from the accommodation space. While controlling the power supply unit so as to apply a voltage between the discharge piston for discharging and the anode and the substrate, at the time of applying the voltage, the supply of the metal solution to the accommodation space by the supply piston is performed. The supply piston and the discharge piston are controlled so that the supply and the discharge of the metal solution from the storage space by the discharge piston are performed and the hydraulic pressure of the metal solution in the storage space is maintained. And a control device for performing the same.

  According to the apparatus for depositing a metal film according to the present invention, by suppressing the adhesion of bubbles in the metal solution to the solid electrolyte membrane, it is possible to suppress the inhibition of the movement of metal ions in the solid electrolyte membrane. Therefore, it is possible to avoid the film formation failure of the metal film.

1 is a schematic cross-sectional view of a metal film forming apparatus according to a first embodiment of the present invention. It is a top view of the film-forming apparatus in the state which removed the solid electrolyte membrane in the film-forming apparatus shown in FIG. It is a typical sectional view for explaining the film forming device of the metal membrane concerning a 2nd embodiment of the present invention.

  Hereinafter, with reference to FIGS. 1 to 3, a metal film forming apparatus according to the first and second embodiments of the present invention will be described.

1. Metal Film Forming Apparatus 1 First, the metal film forming apparatus 1 will be described. FIG. 1 is a schematic sectional view of a metal film forming apparatus 1 according to the first embodiment of the present invention. FIG. 2 is a plan view of the film forming apparatus 1 shown in FIG. 1 with the solid electrolyte membrane 13 removed.

  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 corresponding to a cathode, and a voltage between the anode 11 and the substrate B. And a power supply unit 14 for applying a voltage.

  The anode 11 is electrically connected to the positive electrode of the power supply unit 14 via a chamber (solution containing unit) 15, and the substrate B serving as a 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 G1 for storing the metal solution L is formed inside thereof. The metal solution L may be, for example, an electrolytic solution containing ions of copper, nickel, silver or the like, and the metal forming the metal film is present in the metal solution L in an ionic state.

  An anode 11 is arranged in a storage space G1 for storing 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.

  In the present embodiment, the film forming apparatus 1 includes a supply piston 22 that supplies the metal solution L to the chamber 15 and a discharge piston 23 that discharges the metal solution L from the chamber 15. Specifically, the supply piston 22 is arranged in the chamber 15 so as to be movable up and down, and the supply space G2 for supplying the metal solution L to the accommodation space G1 is formed by the upward movement of the supply piston 22. The supply space G2 communicates with the accommodation space G1 via the first communication hole 15b (see, for example, FIG. 2).

  Accordingly, when the supply piston 22 moves up, the metal solution L in the supply space G2 is pressurized, and the metal solution L can be supplied from the supply space G2 to the accommodation space G1 via the first communication hole 15b. .. The pressure of the pressurized metal solution L can be measured by the pressure gauge 18 attached to the supply space G2.

  Further, in the chamber 15, a discharge piston 23 is arranged so as to be movable up and down, and when the discharge piston 23 descends, a recovery space G3 for recovering the metal solution L from the accommodation space G1 is formed. The collection space G3 communicates with the accommodation space G1 via the second communication hole 15c.

  Accordingly, when the discharge piston 23 descends, the metal solution L can be sucked from the accommodation space G1 into the recovery space G3 via the second communication hole 15c. An exhaust valve 25 is attached to the upper part of the recovery space G3, and bubbles (air) exhausted together with the metal solution L from the accommodation space G1 during film formation can be exhausted from the recovery space G3.

  In the present embodiment, the supply piston 22 and the discharge piston 23 are connected to the electric motors 22a and 22b via a rotation-linear motion conversion mechanism (not shown) so that they can move up and down. ..

  Further, in the present embodiment, the control device 20 is further provided. The control device 20 controls the power supply unit 14 so as to apply a voltage between the anode 11 and the substrate B. In addition to this, the control device 20 supplies the metal solution L to the accommodation space G1 by the supply piston 22 and discharges the metal solution L from the accommodation space G1 by the discharge piston 23, and the inside of the accommodation space G1. The supply piston 22 and the discharge piston 23 are controlled so that the liquid pressure of the metal solution L is maintained within a predetermined range.

  Specifically, the control device 20 controls the rotation speeds of the electric motors 22a and 22b connected to each. Specifically, the supply flow rate of the metal solution L supplied by the supply piston 22 to the housing space G1 and the discharge flow rate of the metal solution L discharged by the discharge piston 23 from the housing space G1 are controlled to be the same. The device 20 controls the rotation speeds of the electric motors 22a and 22b. As a result, the controller 20 controls the ascending speed of the supply piston 22 and the descending speed of the discharge piston 23.

  In addition to this, the control device 20 controls the rising timing of the supply piston 22 and the falling timing of the discharge piston 23 by synchronizing the startup timing of the electric motors 22a and 22b during film formation.

  In this embodiment, the control device 20 controls the electric motors 22a and 22b to control the ascending/descending speed and the ascending/descending timing of the supply piston 22 and the discharge piston 23. However, an air cylinder may be connected to each of the supply piston 22 and the discharge piston 23, and the control device may control the supply cylinder 22 and the discharge piston 23 by controlling the air cylinder via a solenoid valve or the like. .

2. Metal Film Forming Method A metal film forming method according to this embodiment will be described below with reference to FIGS. 1 and 2. First, in the present embodiment, the solid electrolyte membrane 13 is arranged so as to cover the opening 15a of the chamber 15. At this time, the housing space G1 in which the metal solution L of the chamber 15 is housed may be sealed with the solid electrolyte membrane 13, but the metal solution L of the chamber 15 is pressed by pressing the solid electrolyte membrane 13 of the substrate B described later. The accommodation space G1 to be accommodated may be sealed with the solid electrolyte membrane 13.

  Next, the surface of the substrate B is pressed against the solid electrolyte membrane 13 from above the solid electrolyte membrane 13, and the supply piston 22 causes the pressure gauge 18 to have a predetermined pressure. Pressurize.

  In this state, the control device 20 controls the power supply unit 14 so as to apply a voltage between the anode 11 and the substrate B. 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.

  At the time of applying the voltage described above, the control device 20 causes the supply piston 22 to supply the metal solution L to the storage space G1 and the discharge piston 23 to discharge the metal solution L from the storage space G1 while the storage space G1 is being discharged. The supply piston 22 and the discharge piston 23 are controlled so that the liquid pressure of the metal solution L therein is maintained within a predetermined range.

  Specifically, the control device 20 supplies the supply solution piston so that the supply timing of the metal solution L supplied to the storage space G1 and the discharge timing of the metal solution L discharged from the storage space G1 by the discharge piston 23 are synchronized. 22 and the discharge piston 23 are controlled.

  Furthermore, the supply flow rate of the metal solution L supplied to the accommodation space G1 and the discharge flow rate of the metal solution L discharged from the storage space G1 by the discharge piston 23 are equal to each other. Controls the lifting speed and lifting timing. During the film formation, the supply piston 22 supplies the metal solution L to the accommodation space G1 and the discharge piston 23 discharges the metal solution L from the accommodation space G1.

  In this way, even if the bubbles generated at the anode 11 collect on the surface of the solid electrolyte membrane 13 due to buoyancy during the formation of the metal film, the discharge piston 23 causes the bubbles together with the metal solution L, It is discharged from the accommodation space G1 to the recovery space G3 through the second communication hole 15c. The bubbles accumulated in the upper part of the recovery space G3 may be discharged from the exhaust valve 25 during or after the film formation.

  As a result, by suppressing the bubbles in the metal solution L from adhering to the solid electrolyte membrane 13, it is possible to prevent the movement of metal ions in the solid electrolyte membrane 13 from being hindered and to form the metal film. It is possible to avoid defects.

  When the solid electrolyte membrane 13 is replaced after the metal film is formed, the supply piston 22 is lowered and the discharge piston 23 is raised, and then the liquid pressure of the metal solution L in the accommodation space G1 is increased. , Make the pressure the same as atmospheric pressure. Since the accommodation space G1 is opened when the solid electrolyte membrane 13 is removed, the bubbles pushed back into the accommodation space G1 together with the metal solution L by the ejection piston 23 can be ejected from the accommodation space G1 to the atmosphere. it can.

  The first communication hole 15b is exposed below the accommodation space G1 when seen in a plan view (the opening of the first communication hole 15b is formed in the vertical direction (see FIG. 2)). When the solid electrolyte membrane 13 is removed after the bubbles pushed back into the space G2 are stored in the supply space G2, they can be easily discharged from the accommodation space G1 to the atmosphere via the first communication hole 15b.

[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 sectional view for explaining a metal film forming apparatus according to the second embodiment of the present invention.

  The film forming apparatus according to the present embodiment differs from the film forming apparatus according to the first embodiment in that the position of the chamber 15 near the opening of the second communication hole 15c communicating with the accommodation space G1 This is a point in which the chamber 15 is inclined so as to be higher than the other portions forming the space G1.

  In the present embodiment, the film forming apparatus 1 is tilted as a whole. The film forming apparatus 1 may be always tilted via a bracket or the like. For example, the film forming apparatus 1 is supported by a tilt mechanism that is movable by a servomotor, an air cylinder or the like, and the film forming apparatus 1 is formed only during film formation. 1 may be inclined.

  In the present embodiment, due to such an inclination, the bubbles generated at the time of film formation and lifted by the buoyancy can be more reliably flowed to the second communication hole 15c. This makes it possible to efficiently remove the bubbles from the accommodation space G1 of the chamber 15 and avoid the defective formation of the metal film.

  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.

  1: film forming apparatus, 11: anode, 13: solid electrolyte membrane, 14: power supply section, 15 chamber (solution processing section), 22: supply piston, 23: discharge piston, G1: accommodating space, L: metal solution

Claims (1)

An anode,
Between the anode and the substrate corresponding to the cathode, so that the surface of the substrate is in contact, a solid electrolyte membrane disposed above the anode,
A solution storage part in which a storage space for storing a metal solution containing metal ions is formed so as to come into contact with the solid electrolyte membrane and the anode,
Between the anode and the substrate, a power supply unit for applying a voltage, and a metal film forming apparatus,
The film forming apparatus, a supply piston for supplying the metal solution to the accommodation space,
A discharge piston for discharging the metal solution from the storage space,
The power supply unit is controlled so as to apply a voltage between the anode and the substrate, and at the time of applying the voltage, the supply piston supplies the metal solution to the housing space and the discharge piston. While performing the discharge of the metal solution from the storage space by the, so as to maintain the hydraulic pressure of the metal solution in the storage space, a control device for controlling the supply piston and the discharge piston, A metal film forming apparatus, further comprising:

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