JP2019143177A - Method for manufacturing structure having metal film, and structure having metal film - Google Patents

Abstract

To provide a method for manufacturing a structure having a metal film, capable of easily forming a metal film on a structure having a surface consisting of a polymer, and the structure having a metal film available for various applications.SOLUTION: The method for manufacturing a structure having a metal film comprises: the pretreatment step of heating the structure having a surface consisting of a polymer in the presence of oxygen; and the film formation step of heating the structure at a temperature forming the metal in the presence of a mixed fluid obtained by dissolving a reducer and a metal precursor forming metal by the reduction of the reducer in a supercritical fluid to form a metal film on the surface of the structure.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for manufacturing a structure with a metal film and a structure with a metal film.

  Conventionally, physical vapor deposition, chemical vapor deposition, plating, and the like are known as methods for forming a metal film on a structure composed of a polymer. On the other hand, in recent years, it has become possible to obtain a structure having a complicated three-dimensional structure such as a structure having a hole with a high aspect ratio or a microchannel by a 3D printer.

  However, in such a structure having a hole with a high aspect ratio or a structure having a complicated three-dimensional structure, if a metal film is formed on the surface of the structure by physical vapor deposition or the like, only part of the structure is formed. There is a risk that a metal film is formed on the surface.

  On the other hand, a supercritical fluid thin film deposition method (SCFD) in which a metal film is formed on a polymer structure using a supercritical fluid is known (see Patent Document 1). In the fluid thin film deposition method, since there is a substrate selectivity, when a metal film is formed on the surface of a structure composed of a polymer, the reaction does not proceed as it is.

For this reason, pretreatment such as formation of a metal oxide film is required in advance. For example, in Patent Document 1, as a pretreatment to form a desired metal film, a metal oxide precursor such as RuO ₂ and a supercritical fluid in which an oxidant is dissolved are used to perform metal oxidation on the surface of the structure. After forming a film, the metal oxide film is reduced to a metal film using a supercritical fluid in which a reducing agent and a metal precursor are dissolved, and the metal precursor is reduced on the metal film to obtain a desired film. A metal film is formed.

International Publication No. 2005/118910

  However, in Patent Document 1, since a metal oxide film is formed as a pretreatment, not only film formation conditions for forming a desired metal film but also film formation conditions for forming a metal oxide film are provided. It must be studied and requires a lot of work.

  The present invention has been made to solve the above problems. That is, the present invention provides a method for manufacturing a structure with a metal film that can easily form a metal film on a structure having a polymer surface, and a structure with a metal film that can be used for various applications. Objective.

  According to one aspect of the present invention, a pretreatment step of heating a structure having a polymer surface in the presence of oxygen, and after the pretreatment step, a reducing agent and reduction of the reducing agent in a supercritical fluid Forming a metal film on the surface of the structure by heating the structure to a temperature at which the metal is generated in the presence of a mixed fluid in which a metal precursor generated by the metal is dissolved by A method for manufacturing a structure with a metal film is provided.

  In the manufacturing method, the supercritical fluid may be supercritical carbon dioxide.

  In the manufacturing method, the pressure of the oxygen during the pretreatment step may be equal to or higher than atmospheric pressure.

  In the manufacturing method, the metal precursor may contain Cu.

  In the manufacturing method, the reducing agent may be hydrogen.

  In the manufacturing method, the structure may be heated at a temperature of 200 ° C. or higher in the pretreatment step.

  In the manufacturing method, the structure may include a hole, and a ratio of a surface area of the hole to an opening area of the hole may be 25 or more.

  According to another aspect of the present invention, there is provided a structure with a metal film comprising a structure having a surface made of a polymer and a metal film formed on at least a part of the structure. Has a hole, the ratio of the surface area of the hole to the opening area of the hole is 25 or more, and the metal film is formed in a region of 90% or more of the inner surface of the hole. A structure with a metal film is provided.

  According to one aspect of the present invention, it is possible to provide a method of manufacturing a structure with a metal film that can easily form a metal film on a structure having a surface made of a polymer, and can be used for various applications. A structure with a metal film can be provided.

Drawing 1 is a mimetic diagram of a structure used for a manufacturing process of a structure with a metal film concerning an embodiment. FIG. 2A and FIG. 2B are diagrams schematically showing a manufacturing process of the structure with a metal film according to the embodiment. FIG. 3A and FIG. 3B are diagrams schematically showing a manufacturing process of the structure with a metal film according to the embodiment. FIG. 4A to FIG. 4C are diagrams schematically illustrating a manufacturing process of the structure with a metal film according to the embodiment. FIG. 5 is a schematic view of the structure with a metal film according to the embodiment. 6A is an appearance photograph of the structure before the pretreatment process and the film forming process used in Example 1, and FIG. 6B is an appearance of the structure with a metal film according to Example 1. FIG. It is a photograph. The left photograph in FIG. 7 is an appearance photograph of the structure before the pretreatment process and the film forming process used in Example 2, and the middle photograph in FIG. 7 is the appearance of the structure with the metal film according to Comparative Example 1. 7 is a photograph of the right side of the structure with metal film according to the second embodiment. FIG. 8A to FIG. 8C are cross-sectional photographs of a hole portion of the structure with a metal film according to Example 1 using a transmission electron microscope.

  Hereinafter, a manufacturing method of a structure with a metal film and a structure with a metal film according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of a structure used in a manufacturing process of a structure with a metal film according to this embodiment, and FIGS. 2 to 4 schematically show a manufacturing process of the structure with a metal film according to this embodiment. FIG. 5 is a schematic diagram of the structure with a metal film according to the present embodiment.

<Method for producing structure with metal film>
First, a structure 11 having a surface 11A made of a polymer shown in FIG. 1 is prepared. The structure 11 has a surface 11A made of a polymer. The structure 11A includes not only the surface 11A but also the inside thereof from a polymer. However, the structure may not be a polymer as long as the surface is a polymer. The “surface” in the present specification is a concept including the surface of the hole when the structure has a hole as described later.

  Although it does not specifically limit as a polymer, When it assumes that the structure 11 is modeled with 3D printer, it is preferable that the hardened | cured material of a photocurable resin composition is included. The photocurable resin composition contains a photopolymerizable compound, and preferably further contains a crosslinking agent or a polymerization initiator. By including a crosslinking agent, the heat-resistant temperature of the structure can be further improved.

  Examples of the photopolymerizable compound include a radical polymerizable acrylic resin and a cationic polymerizable epoxy resin.

  Examples of the crosslinking agent include 1,6-bis (acrylyloxy) hexane.

  The structure 11 has a hole 11B. However, the shape of the structure is not particularly limited and may be any shape. For example, the structure may have a flat plate shape or a complicated three-dimensional structure.

  In the structure 11, the ratio of the surface area of the hole 11B to the opening area of the hole 11B (the surface area of the hole / the opening area of the hole) may be 25 or more. In physical vapor deposition, chemical vapor deposition, plating, etc., it is difficult to form a metal film uniformly on the surface of the hole having such a ratio. The method of the present invention is particularly effective as a method for forming a metal film on the surface. The method of the present invention is more effective for structures having pores with the above ratio of 100 or more, 150 or more, or 200 or more. The lower limit of the ratio can be 20000 or less, or 2000 or less.

  The hole 11B shown in FIG. 1 is a non-through hole, but the “hole” in this specification may be either a non-through hole or a through hole. The “opening area” refers to the opening area of the inlet unless the inside of the hole is narrowed from the inlet to the depth direction and then widens again, and the inside of the hole is the end of the hole from the inlet to the depth direction. When it is narrowed and spread again, it is set to the smallest opening area among the opening areas. The surface area of the hole can be measured by the BET adsorption method, but can also be obtained by calculation from the shape of the hole. The opening area can be measured using a laser microscope or an optical microscope, but can also be obtained by calculation from the shape of the inlet of the hole.

  In the structure 11, the ratio of the depth of the hole 11B to the inlet diameter of the hole 11B (hole depth / hole inlet diameter: aspect ratio) may be 12.5 or more. In physical vapor deposition, chemical vapor deposition, plating, etc., it is difficult to form a metal film uniformly on the surface of the hole having such an aspect ratio. The method of the present invention is particularly effective as a method for forming a metal film on the surface of the structure. The method of the present invention is more effective for a structure having a hole having an aspect ratio of 50 or more, 75 or more, or 100 or more. The lower limit of the aspect ratio can be 10000 or less, or 1000 or less. The “inlet diameter” in the present specification means the average value of the diameters measured when the hole entrance is circular, and means the average value of the diameters. It means the shortest distance among the distances between two opposing points on the edge of the part. When the hole is a through hole, there are two inlets of the hole. In this case, the inlet having the smallest inlet diameter is defined as the inlet diameter. The entrance diameter can be measured using a laser microscope or an optical microscope. The depth of the hole 11B can be measured using a micrometer. The depth of the hole 11B is measured at 10 locations, and the average value is taken.

  The manufacturing method of the structure 11 having the above-mentioned ratio is not particularly limited. For example, by a stereolithography apparatus (3D printer, apparatus name “RECILS”, manufactured by Photoscience Research Organization, Graduate School of Science, University of Tokyo) Can be obtained.

  After the structure 11 is prepared, as shown in FIG. 2A, the structure 11 is arranged on the heater 21 in the reaction vessel 20 so that the hole 11B is on the inner space side. Next, oxygen is supplied into the reaction vessel 20 as shown in FIG. Thereafter, as shown in FIG. 3A, a pretreatment step of heating the structure in the presence of oxygen is performed in the reaction vessel 20.

  Oxygen is used to modify the surface of the structure. “Modification” in the present specification means to change the surface property of the structure, and if the method of attaching the metal film changes depending on the presence or absence of the pretreatment step, it is determined that the surface property of the structure has changed. can do. When the color of the surface of the structure is transparent or white, the surface of the structure changes from transparent or white to black or brown when the pretreatment step is performed. For this reason, it may be judged from the color of the surface of the structure whether or not it has been modified.

  The heating temperature of the structure 11 during the pretreatment step is preferably 200 ° C. or higher. If the heating temperature is 200 ° C. or higher, the surface 11A of the structure 11 can be sufficiently modified. The lower limit of the heating temperature of the structure 11 during the pretreatment step is more preferable in the order of 215 ° C. or higher and 230 ° C. or higher (higher is preferable). Moreover, it is preferable that the upper limit of the heating temperature of the structure 11 at the time of a pre-processing process is 300 degrees C or less from a viewpoint which can maintain the structure maintenance of the structure 11. FIG. The structure 11 is heated by the heater 21.

  The oxygen pressure during the pretreatment step is preferably at least atmospheric pressure. If this pressure is equal to or higher than atmospheric pressure, a metal film can be formed on the entire inner surface of the hole. The lower limit of oxygen during the pretreatment step is more preferable in the order of 1.4 MPa or more and 1.6 MPa or more (the larger the value, the better). The upper limit of the pressure of oxygen during the pretreatment step may be 2 MPa or less. The oxygen pressure is the arithmetic average of the values obtained by measuring three times with a small pressure transducer.

  The holding time in the pretreatment step is preferably 1 minute or longer. By setting the holding time to 1 minute or longer, the surface 11A of the structure 11 can be sufficiently modified. “Retention time” means the time during which the structure is exposed to oxygen in a heated state.

  Next, as shown in FIG. 3B, oxygen is discharged from the reaction vessel 20.

  Thereafter, as shown in FIG. 4A, a metal precursor, a reducing agent, and a supercritical fluid are supplied into the reaction vessel 20. Then, as shown in FIG. 4B, in the reaction vessel 20, in the presence of a mixed fluid obtained by dissolving a reducing agent and a metal precursor generated by reduction of the reducing agent in a supercritical fluid. 11 is heated to a temperature at which a metal is generated, and a film forming process for forming a metal film 12 on the surface 11A of the structure 11 is performed. Here, the pretreatment step is performed before the film formation step, and the surface made of the polymer of the structure is modified by oxygen. Therefore, if the metal precursor contained in the mixed fluid is reduced, this modification is performed. A metal film can be formed on the formed surface. Thereby, a structure with a metal film is obtained. The term “supercritical fluid” in the present specification means a fluid in a supercritical state. Further, the “metal film” is made of metal and does not substantially contain a metal oxide.

  The supercritical fluid is used to dissolve the reducing agent and the metal precursor. Since the supercritical fluid exhibits high wraparound properties, the use of the supercritical fluid makes it possible to form a metal film on the surface of a structure having a very high hole or a complicated three-dimensional structure. As the supercritical fluid, supercritical carbon dioxide is preferable because it becomes a supercritical state at a relatively low temperature and low pressure and is chemically stable.

The reducing agent is used to reduce the metal precursor. Examples of the reducing agent include hydrogen (H ₂ ), formic acid (HCOOH), and cyclohexane. Among these, hydrogen is preferable from the viewpoint of reducing power.

  The metal precursor is, for example, an organometallic complex. The metal precursor varies depending on the type of metal film to be formed, and is not particularly limited, but includes, for example, Cu, Ni, or Ru.

As a metal precursor containing Cu, Cu (tmhd) ₂ [bis (tetramethylheptanedionate) copper, chemical formula: C ₂₂ H ₃₈ CuO ₄ ], Cu (acac) ₂ [bis (acetylacetonato) copper, chemical formula : C ₁₀ H ₁₄ CuO ₄ ] and Cu (hfac) ₂ [bis (hexafluoroacetylacetonato) copper, chemical formula: C ₁₀ H ₂ F ₁₂ CuO ₂ ].

Examples of the metal precursor containing Ni include NiCp ₂ [bis (cyclopentadienyl) nickel], and examples of the metal precursor containing Ru include Ru (tmhd) ₃ [chemical formula: C ₃₃ H ₅₇ O ₆ Ru ] Etc. are mentioned.

  The amount of the metal precursor is adjusted depending on how much film thickness is desired to be obtained in the metal film 12. That is, when trying to obtain a thick metal film 12, the amount of the metal precursor is increased, and when trying to obtain a thin metal film 12, the amount of the metal precursor is reduced. . For example, when the metal precursor is 10 mg, a metal film having a thickness of about 100 nm can be obtained.

  The “temperature at which the metal is generated” varies depending on the metal precursor to be used. For example, in the case of a metal precursor containing Cu, the temperature is 180 ° C. or higher, preferably 200 ° C. or higher. The temperature may be equal to or higher than the temperature at which the metal is generated, but is preferably 300 ° C. or lower from the viewpoint of maintaining the structure of the structure 11.

  The pressure of the mixed fluid during the film forming process is preferably 7.4 MPa or more. If this pressure is 7.4 MPa or higher, the supercritical state can be obtained, and the reducing agent and the metal precursor can be dissolved. The lower limit of the pressure of the mixed fluid during the film forming process may be 100 MPa or less.

  After the film forming step, as shown in FIG. 4C, the mixed fluid is discharged from the reaction vessel 21, and the pressure is reduced and the temperature is lowered. Thereafter, the structure with metal film is taken out.

  According to the present embodiment, as a pretreatment process for forming the metal film 12 on the structure 11 whose surface 11A is made of a polymer, a very simple process of heating the structure 11 in the presence of oxygen is performed. Therefore, it is not necessary to form a metal oxide film or to examine the film forming conditions. For this reason, the metal film 12 can be easily formed on the structure 11A having the surface 11A made of a polymer.

  The manufacturing method of the structure with a metal film according to the present embodiment includes, for example, a high-pass filter (particularly, a high-pass filter for terahertz band electromagnetic waves), a waveguide (particularly, a waveguide for terahertz band electromagnetic waves), a microchannel, and a microlattice structure. Body, a polarization control three-dimensional chiral structure, a terahertz electromagnetic wave propagation control element, or a method for manufacturing an artificial material having a negative refractive index in a terahertz electromagnetic wave.

  Examples of propagation control elements for terahertz band electromagnetic waves include, for example, a broadband circular polarizing filter (ShengXi Li et al., “Broadband terahertz circular polarizers with single- and double-helical array metamaterials”, Optical Society of America, January 2011 Vol. 28, pp.19-23), ultra-sensitive terahertz band electromagnetic wave polarizer composed of laminated metal slit structures ("Search for limiting refractive index materials and application to terahertz wave band" (Suzuki) Kenji, Applied Physics, Vol. 86, No. 10, 2017, pp. 897-902)), or terahertz lens (Takaherisa path-length lens composed of oblique metal slit array, Applied Physics A , February 2015, Volume 118, Issue 2, pp.397 &#8211; 402).

  An artificial material having a negative refractive index in terahertz band electromagnetic waves is a three-dimensional metal periodic structure (“Intra-connected three-dimensionally isotropic bulk negative index photonic metamaterial”, Optics Express Vol. 18 Issue 12, 2010, pp.12348-12353. ) Is enlarged to 100 times the size, for example.

<Structure with metal film>
A structure with a metal film 10 shown in FIG. 5 is obtained by the above-described method for manufacturing a structure with a metal film, and the surface 11A is made of a polymer 11 and at least a part of the surface of the structure 11 And a metal film 12 formed on 11A. In FIG. 5, members denoted by the same reference numerals as those in FIG. 1 and the like are the same as the members shown in FIG.

  In the structure 11, the ratio of the surface area of the hole 11B to the opening area of the hole 11B (the surface area of the hole / the opening area of the hole) is 25 or more. This ratio may be 100 or more, 150 or more, or 200 or more. Moreover, the lower limit of this ratio can be 20000 or less, or 2000 or less.

  The hole 11B shown in FIG. 5 is a non-through hole, but the “hole” in this specification may be either a non-through hole or a through hole.

  In the structure 11, the ratio of the depth of the hole 11B to the inlet diameter of the hole 11B (hole depth / hole inlet diameter: aspect ratio) is preferably 12.5 or more. The aspect ratio may be 50 or more, 75 or more, or 100 or more. The lower limit of the aspect ratio can be 10000 or less, or 1000 or less.

  The metal film 12 is formed in a region of 90% or more of the inner surface 11C of the hole 11B. If the metal film 12 is formed in a region of 90% or more of the inner surface 11C of the hole 11B, the structure with a metal film can be used for various applications as described later. The metal film 12 is preferably formed in a region of 95% or more of the inner surface 11C of the hole 11B, and most preferably formed in a region of 100%.

  The film thickness of the metal film 12 is not particularly limited. For example, when a terahertz charged electromagnetic wave bypass filter or a terahertz band electromagnetic wave waveguide is used for the structure 10 with a metal film, the viewpoint of controlling the terahertz band electromagnetic wave. Therefore, the thickness is preferably 500 nm or more. The metal film may be filled in the hole.

  Although the use of the structure 10 with a metal film is not particularly limited, for example, a high-pass filter for terahertz band electromagnetic waves, a waveguide for terahertz band electromagnetic waves, a microchannel, a three-dimensional chiral structure for polarization control, and propagation control for terahertz band electromagnetic waves. Examples thereof include an element or an artificial material having a negative refractive index in a terahertz band electromagnetic wave.

  Specifically, when the structure with a metal film is applied to a high-pass filter for terahertz electromagnetic waves, the high-pass filter for terahertz electromagnetic waves is, for example, a plurality of rectangles (preferably made of a polymer and penetrating in the thickness direction) Is provided with a lattice-like structure having square holes, and a metal film formed on the surface of the structure (including the inner surface of the holes). For example, when used for a high-pass filter having a cutoff frequency of 0.1 THz to 1 THz, the thickness of the structure is 1 mm or more and 10 mm or less, and the length of one side of the hole is 150 μm or more and 1500 μm or less. The period may be a length obtained by adding 100 μm to the length of one side of the hole.

  When the structure with a metal film is applied to a terahertz electromagnetic wave waveguide, the terahertz electromagnetic wave waveguide has, for example, a structure in which the surface is made of a polymer and has a rectangular hole penetrating in the longitudinal direction. A body and a metal film formed on the inner surface of the hole. In this case, for example, the length of the structure is 1 cm or more, the vertical length of the hole is 86 μm or more and 710 μm or less, and the horizontal length of the hole is half of the horizontal length of the hole. be able to.

  When the structure with a metal film is applied to the microchannel, the microchannel is formed on the inner surface of the hole and the structure having a surface made of a polymer and having a through hole, for example. A metal film. In this case, for example, the diameter of the hole can be 300 μm or less, and the length of the hole can be 1 cm or more.

  In order to describe the present invention in detail, examples will be described below, but the present invention is not limited to these descriptions.

<Example 1>
First, the structure which has a hole and consists of a polymer was manufactured. The hole was a through hole, and the shape of the inlet of the hole was a rectangle. Moreover, the length of the long side of the inlet diameter of the hole was 7 mm, the length of the short side was 0.4 mm, and the depth of the hole was 5 mm. Therefore, the opening area was 2.8 mm ² and the surface area of the hole portion was 74 mm ² . In this structure, the ratio of the surface area of the hole to the opening area of the hole is 26.4, and the ratio of the depth of the hole to the length of the short side of the hole (aspect ratio) is 12 .5.

  Such a structure uses a commercially available acrylic ester-based photocurable resin composition (manufactured by Dexerials Co., Ltd., product name “UV curable resin SA1120SN”), and an optical modeling apparatus (3D printer, apparatus name “ “RECILS”, manufactured by the Institute of Photoscience, the University of Tokyo Graduate School of Science. Specifically, first, the photocurable resin composition is poured into a gap between a flat plate and a cylindrical plate, and an ultraviolet laser having a wavelength of 405 nm is linearly modulated with time according to the structure to be shaped. Scanned. The size of the gap was 40 μm. When the scanning of one line was completed, the next line was operated by shifting the flat plate. By repeating this, one layer was completed. When one layer was completed, the plane plate was moved in the vertical direction by the gap width to produce the next layer. By repeating this, the above-mentioned structure having a three-dimensional structure was produced.

  After obtaining the structure, the structure was placed in a reaction vessel and the lid was closed. Next, a pretreatment process was performed. Specifically, first, oxygen was supplied into the reaction vessel under conditions of room temperature and pressure of 1 MPa. Thereafter, the structure was heated to 230 ° C. to adjust the pressure to 1.6 MPa. The pressure of oxygen was measured by a small pressure transducer (model number “GM-200KD”, manufactured by Kyowa Denki Co., Ltd.). The oxygen pressure was the arithmetic average value of the values obtained by measuring three times. This state was maintained for 30 minutes. Thereafter, oxygen was discharged.

After performing the pretreatment process, a film forming process was performed. Specifically, first, 10 mg of Cu (tmhd) ₂ was placed in the reaction vessel. Subsequently, hydrogen was supplied into the reaction vessel under conditions of room temperature and a pressure of 1 MPa, and supercritical carbon dioxide was further supplied under conditions of 50 ° C. and a pressure of 9 MPa. In this state, the structure was heated to 200 ° C. And without providing holding time, after that, the mixed fluid was discharged | emitted, and it pressure-reduced to room temperature while reducing pressure to 0.1 MPa. Then, the lid was opened and the structure was taken out from the reaction vessel. Thereby, a structure with a metal film in which a Cu film was formed as a metal film was obtained.

<Example 2>
A structure with a metal film was obtained in the same manner as in Example 1 except that the following structure was used as the structure. The structure had pores and consisted of a polymer. The hole was a through hole, and the inlet of the hole was circular. Moreover, the inlet diameter of the hole was 0.3 mm, and the depth of the hole was 1 mm. In this case, the opening area of 0.09 mm ^2, the surface area of the holes was 1.2 mm ^2. Therefore, in this structure, the ratio of the surface area of the hole to the opening area of the hole is 13.3, and the ratio of the depth of the hole to the inlet diameter of the hole (aspect ratio) is 3.3. there were. The inlet diameter of the hole was measured with an optical microscope, and the depth of the hole was measured with a micrometer.

<Comparative Example 1>
In Comparative Example 1, the film forming process was performed on the structure described in Example 1 under the same conditions as in Example 1 without performing the pretreatment process.

<Comparative Example 2>
In Comparative Example 2, the same structure as in Example 2 was used, and the film formation process was performed under the same conditions as in Example 1 without performing the pretreatment process.

<Surface observation of structure>
When the surfaces of the structures with metal films according to Examples 1 and 2 and the structures according to Comparative Examples 1 and 2 were visually observed, no metal film was formed on the surfaces of the structures according to Comparative Example 1 and No metal film was formed on the surface of the structure according to Example 2 (see the middle photo in FIG. 7). In contrast, a metal film is formed on the surface of the structure with a metal film according to Example 1 (see FIG. 6B), and the metal film is also formed on the surface of the structure with a metal film according to Example 2. It was formed (see the right photo in FIG. 7). 6A is a photograph of the appearance of the structure before the pretreatment process and the film forming process used in Example 1, and FIG. 6B is a structure with a metal film according to Example 1. It is an appearance photograph. Moreover, the left photograph of FIG. 7 is an external appearance photograph of the structure immediately after manufacture before the pretreatment process and film-forming process used in Example 2 are performed, and the middle photograph of FIG. 7 is a metal according to Comparative Example 1. 7 is an appearance photograph of the structure with a film, and the right photograph in FIG. 7 is an appearance photograph of the structure with a metal film according to the second embodiment. Since the metal film-equipped structures according to Examples 1 and 2 were formed with the metal film, the structures and metal films not subjected to the pretreatment process or the film forming process were compared with Comparative Example 2 in which the metal film was not formed. The color of the photograph is different from the structure.

<Internal observation of hole>
When the cross section of the hole part of the structure with a metal film which concerns on Example 1 was image | photographed with the transmission electron microscope, the metal film was formed in the inner surface of a hole part (FIG. 8 (A)-FIG. 8 (C)). reference). 8A to 8C are photographs obtained by photographing a cross section of the hole portion of the structure with a metal film according to Example 1 with a transmission electron microscope. FIG. 8A is a hole portion. FIG. 8B is a photograph at a position of a depth of 2.10 mm from the entrance of the hole, and FIG. 8C is a photograph of a position at a depth of 0.12 mm from the entrance of the hole. It is a photograph in the position of the depth of 4.49mm from the entrance. 8A to 8C, the structure is cut along the depth direction of the hole, and the depth direction of the hole is in the horizontal direction (the inlet side of the hole is on the left side). The photo was taken with the side facing down. Furthermore, when the cross section of the hole part of the structure with a metal film which concerns on Example 1 was observed with the optical microscope, the metal film was formed in all the inner surfaces. For this reason, it was confirmed that the metal film was formed in the area | region of 90% or more of the inner surface of a hole.

DESCRIPTION OF SYMBOLS 10 ... Structure 11 with a metal film ... Structure 11A ... Surface 11B ... Hole 11C ... Inner surface 12 ... Metal film 20 ... Reaction vessel 21 ... Heater

Claims (8)

A pretreatment step of heating a structure having a polymer surface in the presence of oxygen;
After the pretreatment step, the structure is heated to a temperature at which the metal is produced in the presence of a mixed fluid in which a reducing agent and a metal precursor that produces a metal by reduction with the reducing agent are dissolved in a supercritical fluid. Forming a metal film on the surface of the structure,
A method for producing a structure with a metal film.   The production method according to claim 1, wherein the supercritical fluid is supercritical carbon dioxide.   The manufacturing method of Claim 1 whose pressure of the said oxygen in the said pre-processing process is more than atmospheric pressure.   The manufacturing method according to claim 1, wherein the metal precursor contains Cu.   The manufacturing method according to any one of claims 1 to 4, wherein the reducing agent is hydrogen.   The manufacturing method according to claim 1, wherein the structure is heated at a temperature of 200 ° C. or higher in the pretreatment step.   The manufacturing method according to claim 1, wherein the structure has a hole, and a ratio of a surface area of the hole to an opening area of the hole is 25 or more. A structure with a metal film, comprising: a structure having a polymer surface; and a metal film formed on at least a part of the structure;
The structure has a hole, and the ratio of the surface area of the hole to the opening area of the hole is 25 or more,
A structure with a metal film, wherein the metal film is formed in a region of 90% or more of the inner surface of the hole.