Metal coating forming method and metal coating forming device

Abstract

The present invention provides a method for forming a metal coating that can form a homogeneous metal coating with uniform film thickness by stably ensuring the hydraulic pressure of an electrolyte during film formation. In the method for forming a metal coating (F), a substrate (W) is placed on a carrier (13). The porous membrane is brought into contact with the surface of the substrate while sucking gas between the substrate and a porous membrane (12) through which an electrolyte (S) can pass from a suction port (41) of a suction passage (42) formed on the carrier (13). While the surface of the substrate is brought into contact with the porous membrane, the suction passage is blocked. While the suction passage is blocked, the surface of the substrate is pressed by the porous membrane while the electrolyte passes through the porous membrane under the action of the hydraulic pressure of the electrolyte, and metal is precipitated from metal ions in the permeated electrolyte onto the surface of the substrate, thereby forming a metal coating.

Description

Technical Field

[0001] The present invention relates to a method and apparatus for forming a metal film by depositing metal from metal ions contained in an electrolyte onto the surface of a substrate by electrolytic plating or electroless plating to form a metal film derived from the metal ions on the surface of the substrate. Background Art

[0002] For example, as a film-forming method for forming a metal film on the surface of a substrate, a method of forming a metal film by electrolytic plating using a solid electrolyte membrane is proposed in Patent Document 1. Specifically, in the film-forming method described in Patent Document 1, under the action of the hydraulic pressure of the electrolyte, the electrolyte is passed through the solid electrolyte membrane while the surface of the substrate is pressed by the solid electrolyte membrane from one side of the solid electrolyte membrane, and the metal ions of the permeated electrolyte are precipitated on the surface of the substrate by electrolytic plating. Moreover, in the film-forming method described in Patent Document 1, during film formation, the solid electrolyte membrane is attracted from the substrate side in a manner that the substrate and the solid electrolyte membrane are in close contact.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 6056987 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, when the solid electrolyte membrane is a porous membrane, if the film is formed while the porous membrane is being sucked as described in Patent Document 1, the electrolyte may pass through the porous membrane due to suction, thereby leaking to the substrate side. During film formation, if the electrolyte continues to leak to the substrate side, it is difficult to ensure a stable hydraulic pressure, resulting in difficulty in forming a homogeneous metal film with a uniform film thickness.

[0008] Solutions to Solve Problems

[0009] The present invention has been made in view of the above-mentioned points, and provides a method and apparatus for forming a metal film capable of forming a homogeneous metal film having a uniform film thickness by stably ensuring the hydraulic pressure of an electrolyte during film formation.

[0010] In view of the above-mentioned problems, the film-forming method of the metal coating of the present invention utilizes electrolytic plating or electroless plating to precipitate metal from the metal ions contained in the electrolyte onto the surface of the substrate, thereby forming a metal coating on the surface of the substrate. The film-forming method of the metal coating is characterized in that it includes at least the following steps: a step of arranging the substrate on a mounting table; a step of moving the porous membrane toward the substrate while sucking the gas between the substrate and the porous membrane from the suction port of the suction passage formed on the mounting table, so that the porous membrane is in contact with the surface of the substrate; a step of blocking the suction passage while the porous membrane is in contact with the surface of the substrate; and a step of pressing the substrate with the porous membrane while the electrolyte is passed through the porous membrane under the action of the hydraulic pressure of the electrolyte, so that the metal is precipitated from the metal ions of the permeated electrolyte onto the surface of the substrate, thereby forming the metal coating on the surface of the substrate.

[0011] According to the film forming method of the metal coating of the present invention, before forming the metal coating, the substrate is configured on the stage, and the gas between the substrate and the porous film is sucked from the suction port of the suction passage formed on the stage while the porous film is contacted with the surface of the substrate. Thus, it is possible to suppress the invasion of gas (air) between the substrate and the porous film, and to make the porous film and the surface of the substrate uniformly contact. Here, in the state of making the porous film contact the surface of the substrate, the suction passage is cut off, so the suction of the gas from the suction port can be removed. As a result, in the film forming of the metal coating, even if the electrolyte is passed through the porous film while the porous film is pressed on the surface of the substrate under the effect of the hydraulic pressure of the electrolyte, it is also possible to suppress the electrolyte that is passed through from the suction port to continue to flow to the suction passage. In this way, it is possible to uniformly press the surface of the substrate using the porous film under the state of stably maintaining the hydraulic pressure of the electrolyte, and the electrolyte that is passed through can be uniformly supplied to the surface of the substrate, so that a homogeneous metal coating with a more uniform film thickness can be formed on the surface of the substrate.

[0012] As a more preferred embodiment, after the film forming step, the suction passage in the blocked state is communicated with the atmosphere, and after the suction passage is communicated with the atmosphere, the porous membrane is pulled away from the substrate.

[0013] According to this scheme, as described above, in a state where the porous membrane is in contact with the surface of the substrate, during the period from the time when the suction passage is cut off to the time when film formation is completed, the pressure of the suction passage is sometimes maintained as a negative pressure due to the attraction of the gas. Therefore, after the film forming process, by connecting the suction passage in the cut-off state to the atmosphere, the atmospheric pressure can be returned to the suction passage. As a result, after the film forming process, the situation where the porous membrane is difficult to be pulled away from the substrate due to the negative pressure in the suction passage can be eliminated.

[0014] As a more preferred embodiment, in the step of contacting the porous membrane, when the gas is sucked, the electrolyte sucked into the suction passage together with the gas is separated from the gas. According to this embodiment, the electrolyte sucked into the suction passage together with the gas is separated from the gas, so that the electrolyte can be recovered and reused.

[0015] In this specification, a film forming device suitable for performing the above-mentioned film forming method of metal coating is disclosed. The film forming device of the metal coating of the present invention is a film forming device that forms a metal coating on the surface of the substrate by precipitating metal from metal ions contained in the electrolyte onto the surface of the substrate by electrolytic plating or electroless plating, and the film forming device of the metal coating is characterized in that the film forming device at least comprises: a housing that contains the electrolyte; a porous membrane that seals the electrolyte contained in the housing and is mounted on the housing in a manner opposite to the substrate; a hydraulic adjustment device that adjusts the hydraulic pressure of the electrolyte contained in the housing; a mounting table that forms a suction passage on which the substrate is mounted, the suction passage having a suction port for sucking gas between the substrate and the porous membrane; a lifting device that lifts the housing relative to the mounting table; and a suction device that is connected to the suction passage via an opening and closing valve to suck the fluid in the suction passage. ; and a control device, which at least controls the adjustment of the hydraulic pressure of the hydraulic adjustment device, the lifting and lowering of the lifting device, the suction based on the suction device and the opening and closing of the opening and closing valve, the control device at least comprises: a suction execution unit, which executes the suction based on the suction device when the opening and closing valve is in an open state; a descent control unit, which controls the descent of the shell performed by the lifting device during the suction of the suction device until the porous membrane contacts the substrate; a valve closing control unit, which controls the opening and closing valve to be closed after the porous membrane contacts the substrate; a hydraulic pressure increasing unit, which increases the hydraulic pressure of the electrolyte by using the hydraulic pressure adjustment device after the opening and closing valve is closed; and a film forming execution unit, which forms the metal coating on the surface of the substrate while maintaining the hydraulic pressure in the increased state.

[0016] According to the film forming device of the metal coating of the present invention, the suction execution unit is used to perform suction based on the suction device while the opening and closing valve is opened, and the descent control unit is used to control the descent (descent amount) of the housing performed by the lifting device until the porous membrane contacts the substrate. Thus, it is possible to suppress the intrusion of gas (air) between the substrate and the porous membrane, and make the porous membrane and the surface of the substrate contact uniformly. Then, the closed valve control unit is used to control the opening and closing valve to be closed after the porous membrane contacts the substrate, so that the suction of the gas from the suction port can be released.

[0017] Next, after the opening and closing valve is closed, the hydraulic pressure of the electrolyte in the housing is increased by using the hydraulic pressure increasing unit and the hydraulic pressure adjusting device. As a result, during the formation of the metal coating, even if the electrolyte is passed through the porous membrane while the surface of the substrate is pressed by the porous membrane under the action of the hydraulic pressure of the electrolyte in the housing, the electrolyte that has passed through the porous membrane can be suppressed from continuing to flow from the suction port to the suction passage. In this way, the surface of the substrate can be uniformly pressed by the porous membrane while the hydraulic pressure of the electrolyte is stably maintained, and the electrolyte that has passed through can be uniformly supplied to the surface of the substrate, so that a homogeneous metal coating with a more uniform film thickness can be formed on the surface of the substrate by the film forming execution unit.

[0018] As a more preferred embodiment, a connecting passage connecting the suction passage with the atmosphere is connected to the suction passage, and an atmospheric open valve is provided in the connecting passage, and the atmospheric open valve connects the suction passage to the atmosphere and blocks the connection with the atmosphere. The control device further comprises: a connecting and blocking section, which controls the atmospheric open valve to be closed during the period from before the suction performed by the suction execution section starts to the contact of the porous membrane with the substrate by the descent control section, thereby blocking the connection of the suction passage to the atmosphere; a connecting control section, which controls the atmospheric open valve to be open after the metal coating is formed by the film forming execution section, thereby connecting the suction passage to the atmosphere; and an ascending control section, which controls the ascent of the shell performed by the lifting device after the connection with the atmosphere is performed by the connecting control section.

[0019] According to this scheme, the connected isolation part is utilized, and the atmosphere open valve is controlled to be a closed valve during the period from before the suction starts to the porous membrane contacts the substrate, thereby isolating the suction passage from being connected to the atmosphere. Thus, since the suction passage is not connected to the atmosphere, it is possible to stably carry out suction based on the suction device. In addition, the connection control part controls the atmosphere open valve to be an open valve after the film formation of the metal coating performed by the film forming execution part, thereby connecting the suction passage to the atmosphere. Thus, even if the pressure of the suction passage is maintained as a negative pressure due to the suction of the gas during the period from after the suction passage is cut off to the completion of the film formation, the pressure of the suction passage can be returned from the negative pressure to the atmospheric pressure after the film formation. As a result, the following situation can be eliminated: even if the rise of the housing performed by the lifting device is controlled, it is difficult to pull the porous membrane away from the substrate due to the negative pressure in the suction passage.

[0020] As a more preferred embodiment, the film forming device further includes a gas-liquid separation device for separating the gas from the electrolyte and a recovery tank for recovering the separated electrolyte at a position downstream of the on-off valve.

[0021] According to this scheme, the electrolyte that is attracted to the suction passage together with the gas can be separated into gas and electrolyte via a gas-liquid separation device. Since the separated electrolyte is recovered to the recovery tank, the electrolyte contained in the recovery tank can be reused. In particular, in the case where the electrolyte containing gas is supplied into the housing for reuse, since the gas is a compressible fluid, it is difficult to stably increase the hydraulic pressure of the electrolyte. However, in this scheme, the electrolyte from which the gas is separated can be supplied into the housing, and the pressure of the electrolyte in the housing can be stably increased during film formation.

[0022] Effects of the Invention

[0023] According to the metal coating forming method and the film forming apparatus of the present invention, a homogeneous metal coating having a uniform film thickness can be formed by stably ensuring the hydraulic pressure of the electrolyte during film formation. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic cross-sectional view illustrating a state where a substrate is mounted on the metal film forming apparatus according to the first embodiment of the present invention.

[0025] Figure 2 yes Figure 1 A block diagram of a control device for a film forming device is shown.

[0026] Figure 3 It is used Figure 1 A flow chart of a method for forming a metal film using a film forming apparatus shown.

[0027] Figure 4 Yes Description Figure 3 A schematic conceptual diagram of the metal film forming process shown.

[0028] Figure 5 It is a schematic cross-sectional view illustrating a state where a substrate is mounted on a metal coating forming apparatus according to a second embodiment of the present invention, and is a cross-sectional view illustrating a state after a metal coating forming step and before the substrate is recovered.

[0029] Figure 6 It means replacing Figure 1 The film forming device shown and Figure 1 1 is a graph showing the results of the electrolyte leakage rate with respect to the pressure applied to the substrate by the liquid pressure of the electrolyte when a solid electrolyte membrane is used instead of a porous membrane in the film-forming device shown in FIG.

[0030] Figure 7 Yes means Figure 1 The graph of the results of the leakage rate of the electrolyte relative to the time of pressurization to the substrate in the film forming apparatus shown.

[0031] Description of reference numerals:

[0032] 1: film forming device, 11: shell, 12: porous membrane, 13: mounting table, 14: lifting device, 20: hydraulic adjustment device, 31: recovery tank, 41: suction port, 42: suction passage, 43: suction device, 44: opening and closing valve, 45: connecting passage, 46: atmosphere opening valve, 47: gas-liquid separation device, 50: control device, 51: suction execution part, 52: descent control part, 53: connecting isolation part, 54: valve closing control part, 55: hydraulic pressure increasing part, 56: film forming execution part, 57: connecting control part, 58: rising control part, S: electrolyte, W: substrate, F: metal coating. DETAILED DESCRIPTION

[0033] Below, refer to Figure 1 to Figure 5 The first and second embodiments of the present invention are described. Figure 1 , Figure 4 and Figure 5 The dashed lines shown indicate signal lines of control signals output from the control device 50 and signal lines output from the distance measurement sensor 50A and the pressure measurement sensor 50B.

[0034] <First embodiment>

[0035] The method for forming a metal coating F and the film forming device 1 of the present embodiment are applicable when a metal is deposited from metal ions contained in an electrolyte S onto the surface of a substrate W by electroless plating, thereby forming a metal coating F from metal ions on the surface of the substrate W. Here, electroless plating is different from electrolytic plating in which electrolytic deposition is performed by electricity, and is a method of depositing (forming a film) a coating by a chemical reduction reaction. Electroless plating includes displacement plating in which electroplating is performed using the difference in ionization tendency between the metal constituting the substrate and the metal ions contained in the electrolyte, and autocatalytic reduction plating in which electroplating is performed using the reducing power of a reducing agent.

[0036] Below, first, refer to Figure 1 and Figure 2 The film forming apparatus 1 of the metal film F according to the present embodiment will be described. Next, referring to Figure 1 to Figure 4 A method for forming the metal film F according to the present embodiment will be described.

[0037] 1. About film forming device 1

[0038] Figure 1 It is a schematic cross-sectional view illustrating a state in which a substrate W is mounted on a film forming apparatus 1 for forming a metal film F according to the first embodiment of the present invention. Figure 2 yes Figure 1 A block diagram of a control device 50 of the film forming apparatus 1 is shown.

[0039] The film forming apparatus 1 of this embodiment is a film forming apparatus (electroplating apparatus) that forms a metal film F by electroless plating via a porous membrane 12, and is used when forming (forming) a metal film F on the surface of a substrate W. In addition, the film forming apparatus 1 is used when the metal film F is formed continuously on the surfaces of a plurality of substrates W.

[0040] As for the substrate W, when the electroless plating is displacement plating, as the substrate W, it is preferred to use a metal material composed of a metal (less noble metal) (metal with a large ionization tendency) that is cheaper than the metal ions contained in the electrolyte S. In addition, a layer composed of a metal that is cheaper than the metal ions contained in the electrolyte S can also be formed on the surface of the substrate body of the substrate W. In this case, as the substrate body, a metal material (more noble metal material) or a resin material that is more noble than the metal ions contained in the electrolyte S can also be used. As an example of such a substrate W, when the metal ions contained in the electrolyte S are Au ions, an example of forming a Ni plating layer on the surface of the substrate body composed of Cu can be cited.

[0041] In the case where the electroless plating is a self-catalytic reduction plating, as the substrate W, as long as it is a material having a catalytic effect to promote the oxidation reaction of the reducing agent, a metal material or a resin material may be used. In addition, a layer composed of a metal that serves as a catalyst may be formed on the surface of the substrate body of the substrate W. In this case, a metal material and a resin material that do not have a catalytic effect may be used as the substrate body of the substrate W. As an example of such a substrate W, when the metal ions contained in the electrolyte S are Ni ions, an example of forming a Pd plating layer that serves as a catalyst on the surface of the substrate body composed of Cu can be cited.

[0042] like Figure 1 As shown, the film forming apparatus 1 includes at least a housing 11 , a porous membrane 12 , a mounting table 13 , a lifting device 14 , a hydraulic adjustment device 20 , a suction unit 40 , and a control device 50 .

[0043] The housing 11 contains the electrolyte, and the porous membrane 12 seals the electrolyte S contained in the housing 11 and is installed on the housing 11 in a manner opposite to the substrate W (specifically, the mounting table 13). More specifically, the porous membrane 12 is installed on the housing 11 in a manner that the surface of one side of the porous membrane 12 is in contact with the electrolyte S contained in the housing 11, and the surface of the other side faces the substrate W. The porous membrane 12 is a membrane that allows the electrolyte S to pass through in the film thickness direction, and is a membrane having a plurality of holes that allow the electrolyte S to pass through.

[0044] The thickness of the porous membrane 12 is preferably, for example, 10 μm to 200 μm, more preferably 20 μm to 160 μm. The average pore size of the porous membrane 12 can be, for example, 0.1 μm to 100 μm, for example, it can be a fine hole with an average pore size of 20 to 100 nm, and the pore size of the porous membrane 12 is not particularly limited as long as the electrolyte S in the housing 11 can be pressurized to pass (permeate) through the pores of the porous membrane 12 in the film thickness direction.

[0045] In addition, in the present embodiment, the porous membrane 12 may not have an ion exchange functional group (cation exchange functional group or anion exchange functional group) such as a solid electrolyte. Thus, the porous membrane 12 has almost no polarity, and the metal ions contained in the electrolyte S are not enclosed in the porous membrane and can penetrate the hole. Therefore, such a porous membrane 12 is applicable in any case where the metal ions contained in the electrolyte S are positive ions, negative ions or non-ionic. As such a porous membrane 12, a polyolefin resin can be used. As a polyolefin resin, for example, polyethylene resin, polypropylene resin or a resin mixed therewith can be cited.

[0046] On the other hand, the porous membrane 12 can also use a solid electrolyte with an ion exchange functional group. The solid electrolyte is not particularly limited as long as it can make the metal ions permeate by contacting with the electrolyte S and can precipitate the metal from the metal ions on the surface of the substrate W. As a solid electrolyte, for example, fluorine resins such as Nafion (registered trademark) made by DuPont (DUPONT), hydrocarbon resins, polyamic acid resins, SELEMIONAMV (CMV, CMD, CMF series) made by Asahi Glass Co., Ltd., etc. can be cited. Resin with cation exchange function.

[0047] The electrolyte S is a liquid supplied to one side of the porous membrane 12, and is a liquid containing at least metal ions precipitated as the metal of the metal film F by electroless plating. It should be noted that the electrolyte S for displacement plating or autocatalytic reduction plating is sold on the market as an electroplating solution, and a commercially available electroplating solution can be used.

[0048] When the electroless plating is displacement plating, the metal of the metal ion contained in the electrolyte S is a metal that is more noble (has a lower ionization tendency) than the material of the substrate W. For example, when the substrate W is composed of Cu, the metal of the metal ion can be Ag, Pt, Au, etc.

[0049] In the case where the electroless plating is a self-catalytic reduction plating, the electrolyte S contains metal ions precipitated as the metal of the metal film F and a reducing agent. The metal used as the metal ion is not particularly limited as long as it is a metal with a catalytic effect, and for example, Ag, Pt, Au, etc. can be cited. As the reducing agent, hypophosphorous acid or dimethylamine borane can be cited. The electrolyte S may also contain a stabilizer, a ligand, a reducing agent, etc.

[0050] As described above, the case 11 has a space for storing the electrolyte S, and the porous membrane 12 is mounted while storing the electrolyte S. The case 11 is provided with a supply port 11a for supplying the electrolyte S and a discharge port 11b for discharging the electrolyte S.

[0051] The mounting table 13 mounts the substrate W at a position facing the porous membrane 12. In this embodiment, the mounting table may have conductivity or non-conductivity. A suction passage 42 having a suction port 41 is formed on the mounting table 13. The suction port 41 and the suction passage 42 will be described later.

[0052] In addition, a receiving recess 13a for receiving the substrate W is formed on the mounting table 13, and the depth of the receiving recess 13a is consistent with the thickness of the substrate W. Therefore, when the substrate W is received in the receiving recess 13a, the surface of the substrate W and the surface of the mounting table 13 are preferably arranged in the same plane. Thus, it is possible to suppress excessive stress on the porous membrane 12 during film formation.

[0053] The lifting device 14 is a device for lifting the housing 11 relative to the mounting table 13 (see Figure 1 , 4 In the present embodiment, the lifting device 14 is a device for lifting the housing 11 in the interval from the position where the porous membrane 12 is separated from the substrate W to the position where the porous membrane 12 is in contact with the substrate W, and is disposed on the upper part of the housing 11. The lifting device 14 can be formed by a hydraulic or pneumatic cylinder, an electric actuator, a linear guide, and a motor as long as it can lift the housing 11.

[0054] The hydraulic pressure adjustment device 20 adjusts the hydraulic pressure of the electrolyte S contained in the housing 11. The hydraulic pressure adjustment device 20 is composed of a cylinder 21 and a piston 22, and is connected to the supply port 11a of the housing 11 via a pipe 35 on the supply system side described later. In the hydraulic pressure adjustment device 20, as described later, the hydraulic pressure of the electrolyte S contained in the housing 11 can be adjusted by advancing or retreating the piston 22 relative to the cylinder 21.

[0055] It should be noted that, here, the hydraulic adjustment device 20 is described as an example consisting of the cylinder 21 and the piston 22, but the hydraulic adjustment device 20 is not limited to this. For example, when the discharge valve 34 is a pressure regulating valve, as described later, the electrolyte S in the housing 11 can be pressurized at a predetermined pressure by the discharge valve 34 and the pressure pump 32 while supplying and discharging the electrolyte S. However, considering the ease of high pressure, the improvement of pressure control accuracy, and the suppression of pulsation, it is preferred that the hydraulic adjustment device 20 is composed of the cylinder 21 and the piston 22.

[0056] Furthermore, the film forming apparatus 1 of the present embodiment includes a recovery tank 31 connected to the supply port 11a and the discharge port 11b via a pipe 35. A pressure pump 32 is provided between the recovery tank 31 and the supply port 11a. In addition, a supply valve 33 is provided between the pressure pump 32 and the supply port 11a to block the pipe 35 on the supply system side, and a discharge valve 34 is provided between the discharge port 11b and the recovery tank 31 to block the pipe 35 on the discharge system side.

[0057] The recovery tank 31 is a container that contains the electrolyte S and supplies the contained electrolyte S to the housing 11. The pressure pump 32 is a pump that draws the electrolyte S from the recovery tank 31 and pressure-feeds the electrolyte S into the housing 11 through the supply port 11a. The supply valve 33 and the discharge valve 34 are valves that supply and discharge the electrolyte S contained in the housing 11 in the open valve state, and are valves that ensure the airtightness of the housing 11 in the closed valve state. As the supply valve 33 and the discharge valve 34, for example, an electromagnetic valve can be cited.

[0058] The electrolyte S delivered from the recovery tank 31 by the pressure pump 32 flows into the housing 11 from the supply port 11a through the supply valve 33. The electrolyte S flows from the supply port 11a side to the discharge port 11b side in the housing 11, and is discharged from the discharge port 11b and recovered in the recovery tank 31 through the discharge valve 34.

[0059] The suction unit 40 has a function of sucking gas (e.g., air) between the substrate W and the porous membrane 12 from the side of the mounting table 13. This prevents the gas from being drawn between the surface of the substrate W and the porous membrane 12. The suction unit 40 includes at least a suction passage 42 having a suction port 41, a suction device 43, and an on-off valve 44.

[0060] A suction port 41 is formed at one end of the suction passage 42, and the portion of the suction passage 42 comprising the suction port 41 is formed on the stage 13. The configuration, shape and number of the suction port 41 are not particularly limited as long as the gas between the substrate W and the porous membrane 12 can be attracted. For example, a plurality of suction ports 41 may be formed at equal intervals around the substrate W on the surface of the stage 13. At the other end side of the suction passage 42, a suction device 43 is connected via a gas-liquid separation device 47 described later, and a recovery tank 31 of the electrolyte S separated by recovery is connected to the gas-liquid separation device 47.

[0061] The suction device 43 is connected to the suction passage 42 via the gas-liquid separation device 47, and is a device that sucks the fluid (gas and electrolyte S) in the suction passage 42. The suction device 43 can suck the gas in the suction passage 42 by sucking the gas separated on the gas phase side of the gas-liquid separation device 47. The suction device 43 is not particularly limited as long as it can suck the fluid, but as an example, a vacuum pump can be cited.

[0062] The suction passage 42 is provided with an on-off valve 44. The on-off valve 44 is a valve that blocks the suction passage 42 and is provided between the suction port 41 and the gas-liquid separation device 47. When the on-off valve 44 is in an open valve state, the fluid can flow in the suction passage 42 by suction of the suction device 43. On the other hand, when the on-off valve 44 is in a closed valve state, the flow of the fluid in the suction passage 42 is blocked.

[0063] In the present embodiment, the suction section 40 further includes a communication passage 45, an atmosphere opening valve 46, and a gas-liquid separation device 47. The communication passage 45 is a passage that is connected to the atmosphere, and is connected to the suction passage 42 between the suction port 41 and the on-off valve 44. The atmosphere opening valve 46 is a valve (e.g., a solenoid valve) that connects the suction passage 42 to the atmosphere via the communication passage 45 and blocks the connection, and is provided in the communication passage 45. When the atmosphere opening valve 46 is in an open valve state, the suction passage 42 can be connected to the atmosphere via the communication passage 45. On the other hand, when the atmosphere opening valve 46 is in a closed valve state, the connection of the suction passage 42 to the atmosphere via the communication passage 45 is blocked.

[0064] The gas-liquid separation device 47 is a device having the function of separating a mixed fluid mixed with gas and electrolyte S into gas and electrolyte S downstream of the on-off valve 44. A space for accommodating fluid is formed in the gas-liquid separation device 47, gas is accumulated above the space, and electrolyte S is accumulated below. In addition, a gas-liquid inlet 47a is provided in the gas-liquid separation device 47, and the gas-liquid inlet 47a is connected to the other end of the suction passage 42. In addition, a gas outlet 47b and a liquid outlet 47c are provided on the gas phase side and the liquid phase side of the gas-liquid separation device 47, respectively. The gas outlet 47b is connected to the suction device 43 via the gas outflow passage 48. On the other hand, the liquid outlet 47c is connected to the recovery tank 31 via the liquid outflow passage 49.

[0065] In such a suction unit 40, when the on-off valve 44 is in an open state, the suction passage 42 communicates with the gas-liquid separation device 47 and the suction device 43. At the same time, the suction passage 42 communicates with the gas-liquid separation device 47 and the recovery tank 31.

[0066] Thus, as described later, when gas is sucked into the suction passage 42 during suction, the sucked gas is sucked into the suction device 43 via the gas-liquid separation device 47. On the other hand, when the electrolyte S is sucked into the suction passage 42 together with the gas, the mixed fluid of the sucked gas and the electrolyte S is separated into gas and electrolyte S by the gas-liquid separation device 47. The separated gas is sucked into the suction device 43, and the separated electrolyte S is discharged into the recovery tank 31. The discharged electrolyte S is supplied again into the housing 11, so that the leaked electrolyte S can be effectively recovered.

[0067] In the present embodiment, the film forming apparatus 1 further includes a distance measuring sensor 50A, a pressure measuring sensor 50B, and a control device 50 in order to stop the suction of the gas by the suction unit 40 during film formation.

[0068] The distance measuring sensor 50A is a displacement sensor such as a proximity sensor for measuring the distance between the porous membrane 12 and the substrate W, and is mounted on the housing 11. As the distance measuring sensor 50A, a sensor using, for example, infrared rays, electromagnetic waves, or magnetism can be cited. The pressure measuring sensor 50B is a sensor for measuring the pressure (hydraulic pressure) adjusted by the hydraulic adjustment device 20, and is mounted on the housing 11. The distance measuring sensor 50A and the pressure measuring sensor 50B are electrically connected to the control device 50 so that the measured values ​​measured by the distance measuring sensor 50A and the pressure measuring sensor 50B are input to the control device 50 as signals.

[0069] The control device 50 is a device that controls at least the lifting and lowering of the lifting device 14, the suction of the suction device 43, the adjustment of the hydraulic pressure of the hydraulic pressure adjustment device 20, and the opening and closing of the opening and closing valve 44. The control device 50 uses a computing device such as a CPU, a storage device such as a RAM, and a ROM as a basic structure as hardware. In the computing device, based on the signal calculation of the distance measuring sensor 50A and the pressure measuring sensor 50B, the control signal of the suction device 43, the hydraulic pressure adjustment device 20, and the opening and closing valve 44 is calculated, and these signals are output. In addition, in the storage device, for example, the range of the predetermined distance between the porous membrane 12 and the substrate W and the range of the pressure (hydraulic pressure) during the predetermined film formation are stored.

[0070] In this embodiment, the control device 50 is electrically connected to the lifting device 14 , the hydraulic adjustment device 20 , the supply valve 33 , the discharge valve 34 , the suction device 43 , the opening and closing valve 44 , the atmosphere release valve 46 , and the pressure pump 32 so as to be able to control them.

[0071] like Figure 2 As shown, the control device 50 includes at least a suction execution unit 51, a descending control unit 52, a valve closing control unit 54, a hydraulic pressure increasing unit 55, and a film forming execution unit 56 as software. In addition, when the film forming device 1 has an atmospheric release valve 46, the control device 50 includes a communication isolation unit 53, a communication control unit 57, and a rising control unit 58 as software.

[0072] First, the control device 50 receives an input signal (a command signal for starting film formation) from the input device, and executes the following software content. The suction execution unit 51 executes suction by the suction device 43 when the on-off valve 44 is in an open state. Specifically, the suction execution unit 51 receives a signal indicating that the on-off valve 44 is open, and when the suction device 43 is, for example, a vacuum pump, the suction execution unit 51 drives the vacuum pump. It should be noted that when the film forming device is not driven, the on-off valve 44 is in an open state, but the suction execution unit 51 opens the on-off valve 44 when the on-off valve 44 is in a closed state. In addition, the suction execution unit 51 sends a suction start signal indicating the start of suction to the descent control unit 52.

[0073] The descent control unit 52 controls the descent of the housing 11 by the lifting device 14 based on the output signal of the distance measuring sensor 50A, so that the housing 11 is lowered to a position where the porous membrane 12 contacts the substrate W. After the descent starts by the lifting device 14, the descent control unit 52 determines that the porous membrane 12 contacts the substrate W when the distance measured by the distance measuring sensor 50A reaches a predetermined distance. At this time, the descent by the lifting device 14 is stopped, and a descent stop signal is sent to the valve closing control unit 54.

[0074] In the present embodiment, by such control, the porous membrane 12 can be moved toward the substrate W while sucking the gas between the substrate W and the porous membrane 12 from the suction port 41 of the suction passage 42 formed on the mounting table 13, so that the porous membrane 12 contacts the surface of the substrate W. As a result, the intrusion of gas (air) between the substrate W and the porous membrane 12 can be suppressed.

[0075] The communication cutoff section 53 controls the atmosphere open valve 46 to be closed to cut off the communication with the atmosphere from before the suction by the suction execution section 51 starts to the porous membrane 12 by the descent control section 52 contacts the substrate W. It should be noted that when the atmosphere open valve 46 is in the closed valve state, the atmosphere open valve 46 is maintained in this state. For example, the atmosphere open valve 46 can be closed by receiving an input signal of the start of film formation from an input device. Figure 2 Not shown, but for example, the descent start signal performed by the descending control section 52 can also be received and the closed valve control of the atmosphere open valve 46 performed by the connected shutoff section 53 can be performed. As long as the closed valve control of the atmosphere open valve 46 can be performed before the porous membrane 12 performed by the descending control section 52 contacts the substrate W from the suction execution section 51 before the suction starts, then the timing is not particularly limited. It should be noted that the connected shutoff section 53 can also send the signal representing the closed valve completion of the atmosphere open valve 46 to the closed valve control section 54 as required.

[0076] After the porous membrane 12 is contacted with the substrate W by the descending control unit 52, the valve closing control unit 54 controls the opening and closing valve 44 to be closed in the present embodiment. Specifically, the valve closing control unit 54 receives the control signal of the descending stop of the descending control unit 52, receives the control signal of the valve closing completion of the connecting cutoff unit 53 as required, and controls the opening and closing valve 44 to be closed. It should be noted that, in addition, the valve closing control unit 54 can also directly receive the detection signal (the signal that the porous membrane 12 has been in contact with the substrate W) from the distance measuring sensor 50A instead of the control signal, directly receives the detection signal of the closed valve state from the atmosphere open valve 46 as required, and controls the opening and closing valve 44 to be closed.

[0077] Here, the valve closing control unit 54 can stop the suction of the suction device 43 after closing the opening and closing valve 44, or can continue the suction of the suction device 43. Thereby, the suction passage 42 is blocked (the flow of the gas flowing in the suction passage 42 is blocked). As a result, as described later, it is possible to suppress the leakage of the electrolyte S through the porous membrane 12 caused by suction during film formation, so that the hydraulic pressure of the electrolyte S in the housing 11 can be stabilized. The valve closing control unit 54 sends a valve closing completion signal indicating that the closing of the opening and closing valve 44 is completed to the hydraulic pressure increasing unit 55. The valve closing control unit 54 can receive the closed valve state of the opening and closing valve 44 from the opening and closing valve 44 and send the valve closing completion signal, or after sending the valve closing control signal to the opening and closing valve 44, send the valve closing completion signal after a specified time.

[0078] After the on-off valve 44 is closed, the hydraulic pressure increasing unit 55 increases the hydraulic pressure of the electrolyte S through the hydraulic pressure adjusting device 20. Specifically, the hydraulic pressure increasing unit 55 receives a signal from the valve closing control unit 54 to stop the driving of the pressure pump 32 and close the supply valve 33 and the discharge valve 34 that are in the open valve state. As a result, the inside of the housing 11 is in a sealed state.

[0079] Next, the hydraulic pressure increasing unit 55 advances the piston 22 of the hydraulic pressure adjusting device 20 relative to the cylinder 21. As a result, the electrolyte S is pressure-sent into the sealed housing 11, and the electrolyte S contained in the housing 11 is pressurized. As a result, during film formation, the substrate W can be uniformly pressed by the porous membrane 12 under the action of the hydraulic pressure of the electrolyte S. In addition, the hydraulic pressure increasing unit 55 sends a hydraulic pressure increase signal indicating an increase in hydraulic pressure to the film forming execution unit 56.

[0080] The film forming execution unit 56 forms the metal film F on the surface of the substrate W while maintaining the hydraulic pressure increase state. Specifically, when receiving the hydraulic pressure increase signal, the film forming execution unit 56 receives the signal of the pressure measuring sensor 50B, and based on the signal of the pressure measuring sensor 50B, stops the forward movement of the piston 22 of the hydraulic pressure adjustment device 20 when the prescribed hydraulic pressure is reached. In this way, the prescribed hydraulic pressure can be maintained. The prescribed hydraulic pressure range can be pre-set and stored in the storage device of the control device 50, and the film forming execution unit 56 reads the registered prescribed hydraulic pressure range from the registration unit.

[0081] It should be noted that the film forming execution unit 56 may also receive a signal from the pressure measuring sensor 50B during film forming, and control the hydraulic pressure adjustment device 20 in a manner to maintain a predetermined hydraulic pressure constant when the hydraulic pressure changes. In addition, the film forming execution unit 56 causes the piston 22 of the hydraulic pressure adjustment device 20 to retreat relative to the cylinder 21 when film forming is completed. As a result, the electrolyte S contained in the sealed housing 11 is sucked, so that the contained electrolyte S is depressurized, and as a result, the pressurized state caused by the hydraulic pressure is released. In addition, the film forming execution unit 56 sends a film forming end signal indicating the end of film forming to the communication control unit 57.

[0082] After the metal film F is formed by the film forming execution unit 56, the communication control unit 57 controls the atmosphere opening valve 46 to open the valve to communicate with the atmosphere. Thus, during the period from the time when the suction passage 42 is cut off to the time when the film forming is completed, even if the pressure of the suction passage 42 is maintained at a negative pressure due to the suction of the gas, after the film forming, the pressure of the suction passage 42 can be returned from the negative pressure to the atmospheric pressure. As a result, the following situation can be eliminated: even if the rise of the housing 11 by the lifting device 14 is controlled, it is difficult to pull the porous membrane 12 away from the substrate W due to the negative pressure in the suction passage 42. The communication control unit 57 receives the film forming end signal from the film forming execution unit 56, and sends a communication signal indicating that the suction passage 42 is connected to the atmosphere to the rise control unit 58.

[0083] The lifting control unit 58 controls the lifting of the housing 11 by the lifting device 14 after the atmospheric communication by the communication control unit 57 until the porous membrane 12 is separated from the substrate W. The lifting control unit 58 receives a communication signal from the communication control unit 57 .

[0084] 2. Film forming method of metal film F

[0085] Figure 3 It is used Figure 1 Flow chart of a method for forming a metal film F by the film forming apparatus 1 shown. Figure 4 Yes Description Figure 3 The schematic conceptual diagram of the film forming step S4 of the metal film F is shown in FIG. Figure 3 The process flow shown here explains the method for forming the metal film F according to the first embodiment.

[0086] 2-1. Regarding the step S1 of arranging the substrate W

[0087] In the method for forming the metal coating F of this embodiment, first, a step S1 of arranging the substrate W is performed. In this step, Figure 1As shown, the substrate W is placed on the mounting table 13. Specifically, in a state where the housing 11 is placed above the mounting table 13, the substrate W is placed in the receiving recess 13a of the mounting table 13. Thus, the substrate W is placed at a position facing the porous membrane 12.

[0088] When the substrate W is arranged, the supply valve 33 and the discharge valve 34 are opened, and the pressure pump 32 is driven. Thus, the electrolyte S is supplied from the recovery tank 31 to the housing 11 via the supply port 11a, and the electrolyte S that has passed through the housing 11 is discharged from the housing 11 via the discharge port 11b, and the discharged electrolyte S is returned to the recovery tank 31.

[0089] It should be noted that, although not shown in the figure, the control device 50 may also include a supply and discharge execution unit for supplying and discharging the electrolyte S as described above, and the supply and discharge execution unit opens the supply valve 33 and the discharge valve 34 as described above, and drives the pressure pump 32.

[0090] 2-2. Contact Step S2 of Porous Membrane 12

[0091] Next, the contact step S2 of the porous membrane 12 is performed. In this step, Figure 1 As shown, the porous membrane 12 is moved toward the substrate W by the descent control unit 52 while the gas between the substrate W and the porous membrane 12 is sucked from the suction port 41 of the suction passage 42 formed on the mounting table 13 by the suction execution unit 51, so that the porous membrane 12 contacts the surface of the substrate W.

[0092] Specifically, an input signal for film formation start based on an input device (not shown) is received, and the suction execution unit 51 is used to drive the suction device 43. It should be noted that before the suction device 43 is driven, the suction execution unit 51 is used to maintain the on-off valve 44 in an open state when the on-off valve 44 is in an open state, and to open the on-off valve 44 when the on-off valve 44 is in a closed state. Similarly, before the suction device 43 is driven, the connecting isolation unit 53 is used to close the atmospheric open valve 46 when the atmospheric open valve 46 is in an open state, and to maintain the atmospheric open valve 46 in a closed state. As a result, in the suction passage 42, the connection to the atmosphere via the connecting passage 45 is blocked, and gas or the like can be sucked into the suction passage 42 via the suction port 41.

[0093] When the suction execution unit 51 starts suction, the lowering control unit 52 drives the lifting device 14 based on the output signal of the distance measurement sensor 50A to lower the housing 11 to a position where the porous membrane 12 is in uniform contact with the substrate W disposed in the storage recess 13a.

[0094] By a series of control based on the contact process S2 of such a porous membrane 12, the gas sucked from the suction port 41 can be sucked into the suction passage 42 together with the electrolyte S that has permeated the porous membrane 12. The gas that has passed through the suction passage 42 flows from the gas-liquid inlet 47a to the gas-liquid separation device 47, and is sucked into the suction device 43 from the gas outlet 47b formed on the gas phase side via the gas outflow passage 48. In this way, by sucking the gas between the substrate W and the porous membrane 12 during the period before the substrate W contacts the porous membrane 12, it is possible to suppress the intrusion of gas (air) between the substrate W and the porous membrane 12, and make the porous membrane 12 and the surface of the substrate W contact uniformly.

[0095] On the other hand, the electrolyte S separated from the gas by the gas-liquid separator 47 is introduced into the recovery tank 31 from the liquid outflow port 47 c formed on the liquid phase side via the liquid outflow passage 49 , so that the electrolyte S stored in the recovery tank 31 can be reused.

[0096] Here, the gas phase of the gas-liquid separation device 47 becomes negative pressure due to the suction device 43, so the gas contained in the liquid-phase electrolyte S is easily degassed. As a result, the gas as a compressive fluid is separated from the electrolyte S returned from the recovery tank 31 to the housing 11 for reuse, so that in the film forming step S4 described later, the pressure of the electrolyte S in the housing 11 can be stably increased.

[0097] 2-3. Blocking Step S3 of Suction Passage 42

[0098] Next, the suction passage 42 is blocked step S3. In this step, the suction passage 42 is blocked while the porous membrane 12 is in contact with the surface of the substrate W in the contact step S2 (see Figure 4 Specifically, the valve closing control unit 54 receives a descent stop signal of the housing 11 from the descent control unit 52, and closes the open-close valve 44 in the open state through the valve closing control unit 54. This prevents excessive air and electrolyte S from flowing in the suction passage 42.

[0099] The valve closing control unit 54 sends a valve closing completion signal to the hydraulic pressure increasing unit 55 when the valve closing is completed. Here, the driving of the suction device 43 may be continued, or the driving of the suction device 43 may be stopped when the opening and closing valve 44 is closed. As a result, the suction passage 42 is blocked, and therefore, the suction is stopped at the suction port 41.

[0100] 2-4. Regarding the metal film F forming step S4

[0101] Next, a step S4 of forming a metal film F is performed. In this step, Figure 4As shown, in a state where the suction passage 42 is blocked, the electrolyte S is passed through the porous membrane 12 while the surface of the substrate W is pressed from one side of the porous membrane 12 by the porous membrane 12 under the action of the hydraulic pressure of the electrolyte S. Thus, metal is deposited on the surface of the substrate W from the metal ions of the permeated electrolyte S by electroless plating, thereby forming a metal film F on the surface of the substrate W.

[0102] Specifically, first, the hydraulic pressure increasing unit 55 that has received the valve closing completion signal stops driving the pressure pump 32 and closes the open supply valve 33 and the discharge valve 34. As a result, the supply and discharge of the electrolyte S are stopped, and the housing 11 becomes sealed.

[0103] In this sealed state, the hydraulic pressure increasing unit 55 advances the piston 22 of the hydraulic pressure adjusting device 20 relative to the cylinder 21. This increases the hydraulic pressure of the electrolyte S contained in the sealed case 11. The hydraulic pressure increasing unit 55 sends a hydraulic pressure increasing signal to the film forming execution unit 56.

[0104] The film forming execution unit 56 which has received the hydraulic pressure increase signal receives the pressure signal of the pressure measuring sensor 50B, and stops the forward movement of the piston 22 when the hydraulic pressure reaches a predetermined hydraulic pressure based on the received pressure signal. Thus, the electrolyte S in the housing 11 can be maintained at a predetermined hydraulic pressure, so that during film forming, the porous membrane 12 can be used to press the substrate W in contact with the porous membrane 12 under the effect of the maintained hydraulic pressure.

[0105] As a result, the porous membrane 12 can be conformed to the surface of the substrate W, and the electrolyte S is passed through the porous membrane 12 while the surface of the substrate W is uniformly pressurized by the porous membrane 12, so that metal from the metal ions contained in the electrolyte S is precipitated to form a metal film F on the substrate W. It should be noted that the film thickness of the metal film F can be adjusted by presetting the contact time of the porous membrane 12 (specifically, the precipitation time of the metal).

[0106] In the present embodiment, as described above, the metal coating F is formed in a state where the suction passage 42 is blocked, so that the electrolyte S can be suppressed from passing through the porous membrane 12 due to suction. Thus, it is possible to suppress the lack of hydraulic pressure (pressure) caused by the leakage of the electrolyte S. As a result, a stable hydraulic pressure can be ensured to form a good metal coating F.

[0107] When film formation is completed, the film formation execution unit 56 moves the piston 22 of the hydraulic pressure adjustment device 20 back relative to the cylinder 21 to release the hydraulic pressure pressurization state of the hydraulic pressure adjustment device 20. The film formation execution unit 56 sends a film formation completion signal to the communication control unit 57.

[0108] 2-5. Recovery step S5 of substrate W

[0109] Next, a recovery step S5 of the substrate W is performed. In this step, the blocked suction passage 42 is communicated with the atmosphere, and after the suction passage 42 is communicated with the atmosphere, the porous membrane 12 is pulled away from the substrate W on which the metal film F is formed.

[0110] Specifically, the communication control unit 57 that has received the film formation end signal opens the atmosphere release valve 46. As a result, the suction passage 42 in the negative pressure state from the suction port 41 to the opening and closing valve 44 can be connected to the atmosphere via the communication passage 45, so that the inside of the suction passage 42 becomes atmospheric pressure. The communication control unit 57 sends a communication signal to the rise control unit 58.

[0111] The raising control unit 58, which has received the communication signal, raises the housing 11 using the lifting device 14 (see Figure 1 Thus, even if the pressure of the suction passage 42 is kept at a negative pressure due to the suction of the gas during the period from when the suction passage 42 is cut off to when the film formation is completed, the pressure of the suction passage 42 can be returned from the negative pressure to the atmospheric pressure after the film formation. As a result, the following situation can be eliminated and the porous membrane 12 can be prevented from being damaged: even if the rise of the housing 11 by the lifting device 14 is controlled, the porous membrane 12 is difficult to be pulled away from the substrate W due to the negative pressure in the suction passage 42.

[0112] <Second embodiment>

[0113] Reference Figure 5 , a film forming apparatus 1 of a metal film F and a film forming method of a metal film F according to a second embodiment are described. Figure 5 This is a schematic cross-sectional view illustrating a state in which a substrate W is mounted on a film forming apparatus 1 for forming a metal coating F according to a second embodiment of the present invention. The block diagram of the control device 50 of the film forming apparatus 1 according to the second embodiment is substantially the same as that of the first embodiment, and therefore, only the differences in the block diagram of the control device of the second embodiment will be briefly described below.

[0114] This embodiment is different from the first embodiment in that metal is deposited on the surface of the substrate W by electrolytic plating from metal ions contained in the electrolyte S. Therefore, the following description will focus on the differences, and the same devices and parts as those in the first embodiment are marked with the same reference numerals and their detailed description will be omitted.

[0115] like Figure 5As shown, the film forming apparatus 1 of the second embodiment is provided with a metal anode 18 and a power supply unit 19 for applying a voltage between the anode 18 and the substrate W serving as a cathode, in addition to the above-mentioned components constituting the film forming apparatus 1 of the first embodiment. In this embodiment, a porous membrane 12 is arranged between the anode 18 and the substrate W serving as a cathode, and a constant voltage is applied between the anode 18 and the substrate W by the power supply unit 19 in a state where the porous membrane 12 is in contact with the surface of the substrate W, so that a current flows between the anode 18 and the substrate W during film formation. The substrate W is made of a conductive metal material, for example, Cu, Ni, Ag, Au, etc.

[0116] Anode 18 is accommodated in housing 11, and electrolyte S is arranged between anode 18 and porous membrane 12. When anode 18 is separated from porous membrane 12, anode 18 is plate-shaped, and can be any of a soluble anode made of the same material as metal film F (e.g., Cu) or an anode made of a material insoluble in electrolyte S (e.g., Ti). On the other hand, although not shown in the figure, when anode 18 is in contact with porous membrane 12, as anode 18, an anode made of a porous body that allows electrolyte S to penetrate and supplies metal ions to porous membrane 12 can also be used.

[0117] When the anode 18 is pressed against the porous membrane 12 , uneven deposition may occur due to the deviation of the pressing force of the anode 18 on the porous membrane 12 . Therefore, a structure in which the anode 18 is separated from the porous membrane 12 is preferred.

[0118] The negative electrode of the power supply unit 19 can be electrically connected to the mounting table 13 as long as it can be conductive with the substrate W. Although not shown in the figure, it can also be electrically connected to the substrate W. However, in the case of using a non-conductive mounting table 13, it is more preferable that the negative electrode is electrically connected to the substrate W. The positive electrode of the power supply unit 19 is electrically connected (conductive) to the anode 18 built into the housing 11. It should be noted that the power supply unit 19 can be either a DC power supply or an AC power supply as long as it can perform film formation. The power supply unit 19 is electrically connected to the control device 50 so that the control device 50 can perform control.

[0119] The electrolyte S is not particularly limited as long as it is a liquid containing metal ions precipitated as the metal of the metal film F by electrolytic plating. For example, metals such as Cu, Ni, Ag, and Au can be cited as metal ions. In addition, the electrolyte S may be a liquid obtained by dissolving (ionizing) these metals using an acid such as nitric acid, phosphoric acid, succinic acid, sulfuric acid, or pyrophosphoric acid.

[0120] The configuration of the control device 50 of this embodiment is the same as that of the control device 50 of the first embodiment. However, in addition to the configuration of the first embodiment, the film forming execution unit 56 of this embodiment is different from the first embodiment in that it controls the voltage application of the power supply unit 19. Specifically, the film forming execution unit 56 causes the power supply unit 19 to apply a voltage between the anode 18 and the substrate W while maintaining the hydraulic pressure increase as described above, thereby forming the metal film F. In addition, when the film formation is completed, the film forming execution unit 56 releases the pressurized state as described above, and causes the power supply unit 19 to release the voltage application between the anode 18 and the substrate W.

[0121] The film forming method of the metal coating F of this embodiment is performed in the same manner as the film forming method of the first embodiment described above. However, in this embodiment, in the film forming step of the metal coating F, the voltage between the anode 18 and the substrate W is applied and the voltage is released during film formation, which is different from the first embodiment.

[0122] Specifically, in the film forming process of the metal film F of the present embodiment, as described above, the hydraulic pressure of the electrolyte S in the housing 11 is increased by the hydraulic pressure increasing unit 55 in a state where the suction passage 42 is blocked, and then the hydraulic pressure is maintained. In this maintained state, the film forming executing unit 56 causes the power supply unit 19 to apply a constant voltage between the anode 18 and the substrate W to form the metal film F. Thus, the metal film F derived from the metal ions can be formed on the surface of the substrate W.

[0123] When film formation is completed, the film formation execution unit 56 releases the pressurized state of the hydraulic pressure adjustment device 20 as described above, and the power supply unit 19 stops applying voltage between the anode 18 and the substrate W. Then, the film formation execution unit 56 sends a film formation completion signal to the communication control unit 57 .

[0124] In such a second embodiment, it is needless to say that the same effects as those of the film forming method and the film forming apparatus 1 of the metal film F described in the first embodiment can be obtained.

[0125] [Example]

[0126] Hereinafter, the present invention will be described by way of examples.

[0127] <Example>

[0128] use Figure 1The film forming device of the metal coating of the first embodiment shown in the figure forms the metal coating by displacement plating according to the film forming method of the metal coating of the first embodiment described above. As the electrolyte and the porous membrane, Au plating solution for displacement plating (TDS-25 manufactured by Uemura Industries) and a porous membrane (Poreflon WPW-045-80 manufactured by Sumitomo Electric Industries) were used. The film forming process was carried out with a film forming time of 10 minutes and a hydraulic pressure of 0.2 MPa. As the substrate, a Cu plate plated with Ni was used.

[0129] In the gas suction between the substrate and the porous membrane in the contact process of the porous membrane, the on-off valve is opened, the atmospheric open valve is closed, and the vacuum pump is driven as an suction device. In addition, in the isolation process of the suction passage, the drive of the vacuum pump is maintained, and the on-off valve in the open valve state is closed. In this state, in the film forming process, the metal film is formed, the leakage of the electrolyte in the film forming into the suction passage and the retention of the pressurization (hydraulic pressure) are confirmed, and the film forming property of the metal film (Au film) after the film formation is confirmed.

[0130] <Comparative Example>

[0131] The metal coating was formed in the same manner as in the example, and the leakage of the electrolyte into the suction passage, the pressurization retention, and the film forming properties of the metal coating were confirmed. However, in the comparative example, unlike the example, the suction passage isolation process was not performed. Specifically, in the comparative example, the vacuum pump was maintained driven, and the metal coating was formed in the open state of the on-off valve.

[0132] [Results and Investigation]

[0133] When the suction passage is cut off and the gas suction is stopped as in the embodiment, the leakage of the electrolyte in the housing can be suppressed, and as a result, the pressure in the housing is kept constant, and the Au film is well formed on the substrate. On the other hand, when the suction state of the suction passage is maintained as in the comparative example, it is recognized that the electrolyte in the housing leaks through the porous membrane, and after 1 minute from the start of film formation, the pressurization of the electrolyte in the housing is reduced. Therefore, it is believed that the reason is poor film formation of the Au film.

[0134] Here, as a confirmation test, the vacuum pump was driven and the on-off valve was opened. Figure 1 The leakage rate of the film forming device is shown in the figure and the Figure 1 The leakage rate is measured when a porous membrane of the film forming device shown in the figure is used as a non-porous membrane and a solid electrolyte membrane is used as a non-porous membrane. When measuring the leakage rate, the porous membrane or non-porous membrane (solid electrolyte membrane) is in contact with the surface of the substrate, and the pressure applied to the substrate via the room temperature electrolyte is adjusted according to Figure 6 The values ​​shown represent the pressure applied for 10 minutes each. The results are shown in Figure 6 It should be noted that the leakage rate is the ratio of the electrolyte in the suction passage to the volume in the suction passage. Figure 1 The film forming device shown in the figure heats the electrolyte to 70°C and maintains the pressure at 0.2MPa. Figure 7 The leakage rate was measured for each pressurization time shown. It should be noted that at pressurization time 0 minutes, the electrolyte was not pressurized. The results are shown in Figure 7 .

[0135] It can be seen that Figure 6 As shown, in the case of using a porous membrane, leakage is confirmed, such as Figure 7 As shown in the figure, by increasing the pressurization time, the electrolyte seeps out from the porous membrane even with a slight hydraulic pressure. From these results, it can be said that in order to prevent the electrolyte from seeping out, it is desirable not to perform suction from the suction port during film formation.

[0136] As mentioned above, although one embodiment of the present invention has been described in detail, the present invention is not limited to the above-mentioned embodiment, and various design changes can be made without departing from the scope of the present invention claimed in the claims.

[0137] For example, in the first and second embodiments described above, an example of continuously blocking the suction passage during film formation is described, but the present invention is not limited thereto, and the suction passage during film formation may be blocked intermittently. Thus, when a gas such as hydrogen is generated between the porous membrane and the substrate during film formation, the generated gas can be removed.

[0138] In addition, in the first and second embodiments described above, a film forming device is described in which a gas-liquid separation device is provided in the suction section. However, as long as the mixed fluid consisting of the sucked electrolyte and gas can be separated in the recovery tank, the gas-liquid separation device can be omitted and the recovery tank can be connected to the suction passage via the suction device.

Claims

1. A method for forming a metal coating, wherein the metal is deposited on the surface of a substrate from metal ions contained in an electrolyte by electrolytic plating or electroless plating, thereby forming a metal coating on the surface of the substrate. The method for forming a metal coating is characterized in that it comprises at least the following steps: The step of placing the substrate on a mounting table; A step of moving the porous membrane toward the substrate while sucking gas between the substrate and the porous membrane from a suction port of a suction passage formed on the mounting table to bring the porous membrane into contact with a surface of the substrate; A step of blocking the suction passage while the porous membrane is in contact with the surface of the substrate; and In a state where the suction passage is blocked, the electrolyte is passed through the porous membrane while the substrate is pressed by the porous membrane under the action of the hydraulic pressure of the electrolyte, and the metal is precipitated from the metal ions in the permeated electrolyte onto the surface of the substrate, thereby forming the metal coating on the surface of the substrate.

2. The method for forming a metal coating according to claim 1, wherein: After the step of forming the metal coating on the surface of the substrate, the suction passage in the blocked state is connected to the atmosphere. After the suction passage is connected to the atmosphere, the porous membrane is pulled away from the substrate.

3. The method for forming a metal coating according to claim 1 or 2, characterized in that: In the step of bringing the porous membrane into contact with the surface of the substrate, when the gas is sucked, the electrolyte solution sucked into the suction passage together with the gas is separated from the gas.

4. A film-forming device for forming a metal coating, which is a film-forming device for forming a metal coating on the surface of a substrate by depositing metal from metal ions contained in an electrolyte onto the surface of the substrate by electrolytic plating or electroless plating, The metal coating film forming device is characterized in that the film forming device at least comprises: a housing for containing the electrolyte; a porous membrane that seals the electrolyte contained in the housing and is mounted on the housing so as to face the substrate; a hydraulic pressure adjustment device for adjusting the hydraulic pressure of the electrolyte contained in the housing; A mounting table having a suction passage formed therein and on which the substrate is mounted, wherein the suction passage has a suction port for sucking gas between the substrate and the porous membrane; A lifting device, which lifts the housing relative to the mounting platform; a suction device connected to the suction passage via an on-off valve and sucking the fluid in the suction passage; as well as a control device that controls at least the adjustment of the hydraulic pressure of the hydraulic adjustment device, the lifting and lowering of the lifting device, the suction by the suction device, and the opening and closing of the opening and closing valve, The control device at least comprises: a suction execution unit that executes suction by the suction device when the on-off valve is in an open state; a descent control unit that controls the descent of the housing by the lifting device to a position where the porous membrane contacts the substrate during the suction of the suction device; a closed valve control unit that controls the on-off valve to be closed after the porous membrane comes into contact with the substrate; a hydraulic pressure increasing unit that increases the hydraulic pressure of the electrolyte by using the hydraulic pressure adjusting device after the on-off valve is closed; as well as The film forming executing unit forms the metal film on the surface of the substrate while maintaining the increased hydraulic pressure.

5. The metal film forming device according to claim 4, characterized in that: The suction passage is connected to a communication passage for connecting the suction passage with the atmosphere. The communication passage is provided with an atmosphere release valve, and the atmosphere release valve enables and blocks the suction passage from being connected to the atmosphere. The control device also has: a communication blocking section that controls the atmosphere opening valve to be closed during a period from before the suction by the suction execution section starts to until the porous membrane contacts the substrate by the descent control section, thereby blocking the connection of the suction passage to the atmosphere; a communication control unit that controls the atmosphere release valve to be opened to communicate the suction passage with the atmosphere after the metal film is formed by the film formation execution unit; and A rise control unit controls the rise of the housing by the lifting device after the communication with the atmosphere is performed by the communication control unit.

6. The metal coating forming device according to claim 4 or 5, characterized in that: The film forming device further includes a gas-liquid separation device and a recovery tank at a position downstream of the on-off valve. The gas-liquid separation device separates the gas from the electrolyte, and the recovery tank recovers the separated electrolyte.

Images