JP2003155590A - Method of manufacturing metal fine structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing metal fine structures having sharp corner edges and high perpendicularity in the depth direction by which large quantities and strong bonding of resin molds is attained, and in which a process for removing a binder in void parts from the resin molds is not needed. SOLUTION: The method of manufacturing the metal fine structures includes a process for forming metal thin films on a substrate and resin molds, a process for forming the resin mold stacked body by contacting the metal thin films of the resin molds with the metal thin film on the substrate and pressing in the thickness direction so as to destroy a contaminated layer on the surface layer of each metal thin film and to joint the resin molds with the substrate, and a process for forming metal layers in void parts of the resin mold stacked body by electroforming.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a metal microstructure used in a micromachine or the like.

[0002]

2. Description of the Related Art A direct LIGA (Lithogra
The phie Galvanoformung Abformung method is a useful method. The direct LIGA method is capable of producing a structure having a height of several 100 μm and processing with accuracy in the micron range, and is capable of easily producing a metal microstructure having a high aspect ratio. Applications are expected.

To manufacture a metal microstructure by the direct LIGA method, X (SR) light such as SR (Synchrotron Radiation) light is applied to a resist film formed on a conductive substrate through an absorber mask having a predetermined shape pattern. By irradiating a line, a resin type laminate having a resin type as a resist structure corresponding to the shape pattern of the absorber mask is formed.
Then, after forming a metal layer in the voids of the resin-type laminate by electroforming, the resin mold and the substrate are removed to produce the desired metal microstructure.

Therefore, the number of metal microstructures that can be manufactured is the same as the number of resin molds, and direct LIGA
According to the method, the number of metal microstructures to be obtained is limited by the number of particles entering the absorber mask and the number of irradiations, and thus there is a limit to mass production of metal microstructures.
When an inch wafer is used, the number of metal microstructures that can be manufactured by one irradiation is from several tens to several thousands. In addition, direct LI using X-ray such as SR light
Electron beams and ultraviolet rays can be used by the same process as the GA method. When ultraviolet rays are used, the number of irradiations can be increased as compared with the case where electron beams are used, but ultraviolet rays have a longer wavelength than electron beams. Since the directivity is small, the light is diffracted so much that the corner edges of the resin mold tend to be rounded and the light tends to diverge in the depth direction. Difficult to manufacture.

In addition to the direct LIGA method as described above, a resin mold is manufactured by a mold such as injection molding or reactive injection molding using a fine mold as a method for manufacturing the metal microstructure. After attaching to a conductive substrate to form a resin-type laminate, a metal layer is formed in the holes of the resin-type laminate by electroforming, and then the resin mold and the substrate are removed to obtain the desired metal microstructure. There are ways to make a body.
According to this method, a large number of metal microstructures can be manufactured because a large number of resin molds can be manufactured from one mold by using a metal microstructure manufactured by the direct LIGA method as a mold. be able to. Further, compared to the direct LIGA method, it does not include an irradiation step, which is advantageous in terms of cost and manufacturing time. However, unless the resin mold is firmly fixed on the conductive substrate, the resin mold and the substrate will not be fixed in the subsequent steps. A dimensional change occurs between and, and the precision of the manufactured metal microstructure easily deteriorates.

As a method of fixing the resin mold on the conductive substrate, there is a method of bonding with an adhesive. However, when the resin is bonded with an adhesive, an excess adhesive is applied to the void portion of the resin-type laminate. It may flow in and the electroforming may become insufficient, or the formed metal layer may be uneven. Therefore, after joining, before the electroforming, the adhesive that has flowed into the holes can be removed with a solvent,
Processing such as removal by dry etching is required, and if the removal conditions are too strict, the resin mold will be damaged.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method capable of mass-producing metal microstructures having sharp corner edges and excellent verticality in the depth direction.

A further object of the present invention is to obtain a strong bond between the resin mold and the substrate, and which does not require a step of removing the adhesive in the holes after forming the resin mold laminate. It is to provide a manufacturing method of.

[0009]

A method of manufacturing a metal microstructure according to the present invention comprises a step of forming a metal thin film on a substrate and a resin mold, a metal thin film on the substrate and a metal thin film on the resin mold. The step of destroying the contaminated layer on the surface layer of the metal thin film by contacting and pressing in the thickness direction to form a resin-type laminate by bonding, and forming a metal layer by electroforming in the pores of the resin-type laminate. And a step of forming.

The step of forming the metal thin film is preferably carried out by any one of vacuum vapor deposition, sputtering, ion plating or chemical vapor deposition when the dry method is used, and either electroplating or electroless plating when the wet method is used. It is preferable to carry out.

The difference in lattice constant between the metal forming the metal thin film on the substrate and the metal forming the metal thin film on the resin mold is 20%.
The following is preferable.

The step of destroying and joining the contaminated layer on the surface of the metal thin film to form the resin type laminate is 10 to 1000 k.
It is preferable to use ultrasonic waves of Hz or local heating at 200 ° C. or less.

The difference in lattice constant between the metal forming the metal thin film on the substrate and the metal forming the metal microstructure is preferably 5% or less.

Further, the difference in lattice constant between the metal forming the metal thin film on the substrate and the metal forming the metal thin film on the resin mold is 20% or less, and the metal forming the metal thin film on the substrate and the metal fine 5% difference in lattice constant from the metal that constitutes the structure
The following is more preferable.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The method for producing a metal microstructure of the present invention comprises the steps of forming a metal thin film on a substrate and a resin mold, and bringing the metal thin film on the substrate and the metal thin film on the resin mold into contact with each other. And pressing in the thickness direction to destroy the contaminated layer on the surface of the metal thin film and bond them together to form a resin-type laminate, and forming a metal layer by electroforming in the holes of the resin-type laminate And a process.

An embodiment of the method for producing a metal microstructure of the present invention is schematically shown in FIGS. 1 (a) to 1 (f).

In the step of forming the metal thin film on the substrate and the resin mold, the metal thin film is formed on the substrate 11 and the resin mold 12 shown in FIG. Figure 1 shows the state after the metal thin film is formed.
It shows in (b). A metal thin film 13b is formed on the upper surface of the substrate 11, and a metal thin film 13a is formed on the lower surface of the resin mold 12. In the present invention, the substrate 11 and the resin mold 12 are
Since the resin-type laminated body is formed by bonding and through the metal thin film 13, the thickness of the metal thin film is preferably 0.01 to 10 μm. If it is thinner than 0.01 μm, sufficient bonding strength cannot be obtained. On the other hand, if it is thicker than 10 μm, it takes time to form a thin film although the bonding strength does not increase.

As a method for forming the metal thin film, there are a dry method and a wet method. The dry method is an advantageous method in that the amount of impurities on the metal thin film, which is most problematic when joining the substrate and the resin mold via the metal thin film, can be suppressed to a low level. On the other hand, the dry method requires expensive equipment and has a problem of batch production of a small number of metal thin films. In this respect, the wet method is an advantageous method capable of inexpensively forming a large amount of metal thin film.

As the dry method, vacuum vapor deposition, sputtering, ion plating or chemical vapor deposition is preferable.

Vacuum deposition is carried out in a vacuum of 10 ^-2 Pa or less,
It is a method of forming a thin film by depositing the evaporated material on the substrate by heating the evaporation source and evaporating it, and the device and handling are relatively simple, and the materials of the thin film and the substrate can be freely selected. It is preferable in that a high speed and a thick film can be formed. The vacuum deposition has a drawback that the bond strength between the substrate and the thin film is small, but the bond strength can be increased by a method of raising the substrate temperature or a method of using an ion beam together.

In sputtering, an inert gas such as Ar or Ne introduced into a vacuum container is ionized, and the ions are made to collide with a target made of metal or the like to eject metal atoms or the like in a neutral state, and then to eject. This is a method of depositing metal particles on a substrate to form a film, which is preferable because various types of materials can be formed and the bonding force between the substrate and the thin film is large.

Ion plating is a method in which plasma generated by an electric field is used to ionize or excite evaporated particles generated from an evaporation source to adhere and deposit them on a substrate to which a negative voltage is applied. It is preferable in that the bonding force between the substrate and the thin film is greater than that in vacuum deposition, and that the thin film has good reactivity and crystallinity.

Chemical vapor deposition (CVD)
ition) supplies a thin film material gas onto the substrate, causes chemical reactions such as decomposition, reduction, oxidation and nitridation on the surface of the substrate due to the action of heat, plasma or light, and then deposits and forms a film on the substrate. This method is preferable because it can form a wide range of materials at a temperature much lower than the melting point of the material and has a large bonding force between the substrate and the thin film.

The wet method is preferably electroplating or electroless plating. Electroplating forms a metal thin film on the surface of a substrate by immersing the substrate in an electrolytic bath and passing a direct current between the substrate and a suitable anode to electrolytically reduce the metal ions in the electrolytic bath. It is a preferable method because it is faster than a dry method such as ion plating.

In electroless plating, a substrate pretreated by degreasing is immersed in a plating bath prepared by adding formaldehyde, sodium hypophosphite or sodium borohydride as a reducing agent to an aqueous solution containing metal ions, It is a method of plating by heating to 90 to 100 ° C. without passing an electric current. The deposition rate is slower than that of electroplating, but non-conductors can also be plated, and the uniformity of the thin film is excellent. It is also preferable in terms.

The metal constituting the metal thin film needs to be a metal that exhibits sufficient reactivity in the bonding in the next step, and a metal that does not form a passivation film is preferable. Such metals include Cu, Pd, Ag, Au, Pt, Re,
Rh, etc. The passivation film is a thin and dense oxide or oxyhydroxide film formed on the surface of a metal. Once the passivation film is formed, the reaction can proceed from the viewpoint of thermodynamic equilibrium conditions. Even so, the reaction virtually stops.

The difference in lattice constant between the metal forming the metal thin film on the substrate and the metal forming the metal thin film on the resin mold is 20%.
It is preferably the following, more preferably 10% or less, and further preferably the same kind of metal. If the difference between the lattice constants of both is greater than 20%, the deviation of the crystal structure becomes large, making it difficult to bond, and even if bonded, the bonding strength tends to decrease. The lengths of the three edges of the unit cell of the crystal are a, b, and c, the angle between the a-axis and the b-axis is γ, the angle between the b-axis and the c-axis is α, and the angle between the c-axis and the a-axis is When β, these six constants are called lattice constants, and the difference in lattice constants being 20% or less means that the difference between the corresponding lattice constants of the six lattice constants is two for the two types of metals to be compared. It is 20% or less in any lattice constant.

The difference in lattice constant between the metal forming the metal thin film on the substrate and the metal forming the metal microstructure is preferably 5% or less. Metal microstructure is number 1 by electroforming
If the difference in lattice constant between the metal forming the metal thin film on the substrate and the metal forming the metal microstructure is larger than 5%, the electroforming in the metal microstructure is performed. This is because the metal orientation and grain size are different between the starting portion and the electroforming end portion, and the metal microstructure tends to exhibit physical properties close to those of a bimetal structure.

Therefore, the difference in lattice constant between the metal forming the metal thin film on the substrate and the metal forming the metal thin film on the resin mold is 20% or less, and the metal forming the metal thin film on the substrate and the metal It is more preferable that the difference in lattice constant from the metal constituting the fine structure is 5% or less.

A conductive substrate can be used as the substrate. The thickness of the substrate depends on the application
There is a thin film having a thickness of about 0 μm to a thick film having a thickness of several mm, and the material is not particularly limited. Examples of the material of the conductive substrate include SUS, Al and Cu. Further, as the conductive substrate, a laminated body in which a conductive layer is formed by sputtering or the like on a non-conductive substrate such as Si, glass, ceramics or plastic can also be used as the conductive substrate. Also, a substrate having a metal thin film on a conductive substrate can be used.

FIG. 1A shows a resin mold having holes penetrating in the depth direction. After the resin mold is bonded to the substrate, the opposite side of the bonding surface is polished. An open resin type laminate can also be used. The resin type material is polymethylmethacrylate, polypropylene, polycarbonate, epoxy resin, or the like.

In the present invention, as shown in FIG. 1 (b), the metal thin film 13b on the substrate 11 and the metal thin film 13a on the resin mold 12 are brought into contact with each other and pressed in the thickness direction, so that the surface layer of the metal thin film. A contaminated layer such as an oxide film or an adsorbed film is destroyed and bonded to form a resin type laminate 2 shown in FIG. 1 (c). That is, in the present invention, the resin mold is fixed on the substrate by the solid phase bonding method in which the metal thin film on the substrate and the metal thin film on the resin mold are bonded in a solid state without melting. In the solid-phase joining method, both surfaces are brought into close contact with each other by plastic deformation in the vicinity of the contact interface, and joining is performed by utilizing the movement of atoms by diffusion. When bonding the substrate and the resin mold with an adhesive, excess adhesive flows into the holes of the resin-type laminate, so holes are formed before electroforming in order to form a uniform metal layer in the holes. It is necessary to remove the adhesive that has flowed into the part,
Since the solid-phase bonding method is adopted in the present invention, the pores are in a clean state, and the work of removing the adhesive before electroforming is unnecessary. Further, in the case of joining with an adhesive, since a solvent is contained in the adhesive, a complete contact body cannot be obtained after drying, and in the present invention, since the solid phase joining method does not contain a solvent,
It is also advantageous in that a perfect contact body can be obtained. Further, since the resin mold is firmly fixed on the substrate by the solid phase bonding method, it is possible to suppress the deterioration of accuracy due to the dimensional change in the subsequent steps.

Before the metal thin film on the substrate and the metal thin film on the resin mold are fixed by the solid phase bonding method, the bonding surface is sputtered in an inert gas such as Ar or irradiated with a high-speed electron beam. Smoothing and cleaning is
It is preferable for increasing the bonding strength. In particular, since the amount of impurities on the metal thin film in the wet method is larger than that in the dry method, it is preferable to clean the bonding surface before bonding, but even in the dry method, a large bonding strength can be obtained. It is preferable to smooth the joint surface and wash it.

As the solid phase bonding method, an ultrasonic bonding method performed by ultrasonic waves or a pressure welding method performed by local heating is preferable.

In the ultrasonic bonding method, vibration is applied by ultrasonic waves while pressurizing the contact surface in the solid state, and the energy is used to destroy and remove the contaminated layer consisting of an oxide film and an adsorption film,
It is a joining method, and is a preferable joining method in that strong joining can be obtained in a short time. It is possible to perform ultrasonic bonding while heating, but it is more preferable not to heat because there is no drawback that the heat-affected zone is crystallized and the electrical characteristics are deteriorated. The ultrasonic frequency is preferably 10 to 1000 kHz, more preferably 10 to 100 kHz. 10 kHz
If it is smaller, it becomes difficult to sufficiently destroy the contaminated layer, and sufficient bonding strength cannot be obtained. On the other hand, 1000
If the frequency is higher than kHz, the energy will be high, and the resin mold or the like may be damaged. Pressurization condition is 0.01-100MP
a is preferable, and 0.01 to 50 MPa is more preferable.
If it is less than 0.01 MPa, plastic deformation hardly occurs in the vicinity of the contact interface, so that sufficient bonding strength cannot be obtained. On the other hand, if the pressure exceeds 100 MPa, the resin mold or the like may be deformed and damaged.

In the pressure contact method, while the substrate and the resin mold are butted against each other, one of them is rotated to generate frictional heat in the metal thin film on the contact surface to locally heat the metal thin film, and the metal thin film is appropriately softened. When it comes to a state, stop the rotation,
Further pressure is applied to bond. It is also possible to locally heat the contact surface by electric heating and bond under pressure. A contaminated layer such as an oxide film or an adsorbed film on the surface of the contact surface is destroyed, miniaturized, decomposed, and extruded, so that sufficient bonding strength can be obtained. The temperature of the contact surface during local heating is 200 ℃
The following is preferable, and 150 ° C. or less is more preferable. When the temperature is high, the metal thin film softens and is easily plastically deformed, and at the same time, atomic diffusion becomes active, which facilitates bonding.
When the temperature is higher than 00 ° C, the resin mold is softened and it becomes difficult to obtain a resin mold laminate having a predetermined shape. Pressurization condition is 0.01-10
0 MPa is preferable, and 0.01 to 50 MPa is more preferable. If it is less than 0.01 MPa, it is difficult for plastic deformation to occur on the contact surface, and it is difficult to obtain sufficient bonding strength. On the other hand, if the pressure exceeds 100 MPa, the resin mold or the like may be deformed and damaged.

The step of forming the metal layer in the void portion of the resin type laminate is performed by electroforming. That is, as shown in FIG. 1D, electroforming is performed using a metal ion solution to obtain a substrate 1
The metal layer 14 is formed on the metal thin film 13b formed on the surface 1. After the metal layer 14 is formed, the resin-type laminate is polished or ground to have a predetermined height.

Subsequently, the resin mold on the substrate is removed by ashing with oxygen plasma or the like, or irradiating with X-rays or ultraviolet rays. As a result, the structure shown in FIG. 1E is obtained. The resin mold 12 shown in FIG. 1 (a) can be reproduced in large quantities as a master mold of a metal microstructure manufactured by, for example, the direct LIGA method.
By electroforming No. 2, it is possible to produce a large amount of metal microstructures.

Finally, the substrate is removed. As shown in FIG. 1E, since the metal thin film 13 remains on the substrate 11, the metal thin film 13 is also removed when the substrate 11 is removed. These are removed by dissolving with a suitable solvent or by dry etching. As a result,
The metal microstructure 1 shown in (f) is obtained. This metal microstructure 1 has a width of several μm to several 100 μm and a height of several μm.
The structure has a size of 00 μm or less, and has sharp corner edges,
It has excellent verticality in the depth direction, and it can manufacture complicated shapes, and does not require assembly work of fine parts.

The method of manufacturing the resin mold is shown in FIG.
An embodiment is shown in (d). As shown in FIG. 2B, a mold having a convex portion 25 shown in FIG. 2A is used to perform molding such as injection molding or reactive injection molding to form a resin mold 22a having a concave portion. A resin mold 22a having a recess after removing the mold is shown in FIG. 2 (c).
The resin mold 22a having the concave portion is polished to manufacture the resin mold 22 in a penetrating state shown in FIG. 2 (d). After bonding the substrate to the opening of the resin mold 22a shown in FIG.
By polishing the surface of 2a opposite to the bonding surface,
It is also possible to manufacture a resin mold for electroforming (similar to the structure shown in FIG. 1C).

Example 1 A structure made of Ni having a width of 50 μm and a height of 50 μm was pasted on a SiN substrate using an epoxy resin as an adhesive. Using this as a mold, polymethylmethacrylate was used for reactive injection molding. After removing the mold, the resin mold having the concave portion was polished to obtain a resin mold penetrating in the depth direction.

RF sputtering was carried out on one surface of this resin mold with Ar as an inert gas and Cu as a target to form a Cu thin film of 0.5 μm on the resin mold.
Similarly, RF sputtering was performed on a substrate made of SiN to form a Cu thin film of 0.5 μm.

The resin type Cu thin film surface and the substrate Cu thin film surface are brought into contact with each other and pressurized at 1 MPa, and then 500 kH at room temperature.
Ultrasonic waves of z were bonded for 1 second to form a resin type laminate. A clean Cu metal surface was visible in the voids of this resin-type laminate.

Nickel sulfamate (450 g / L)
And boric acid (30g / L), current density 100mA
/ Cm ² , pH 4, and temperature of 50 ° C. for 60 minutes to fill the voids of the resin-type laminate by electroforming. After that, it is polished to a predetermined thickness, followed by ashing with oxygen plasma to remove the resin mold on the substrate and dry etching to remove the substrate and the metal thin film. The target width is 50 μm and height is 50 μm. As a result, a structure made of Ni was obtained.
It has been found that this structure has sharp edges and is excellent in verticality in the depth direction, which makes it possible to mass-produce metal microstructures having the same shape.

Example 2 A Ni structure having a width of 40 μm and a height of 60 μm was attached on a SiC substrate by using an epoxy resin as an adhesive. This was used as a mold, and injection molding was performed using polypropylene as a resin material. The mold was removed to obtain a resin mold having a recess.

In addition to this resin mold, a SiC substrate was prepared, and both the resin mold and the substrate were immersed in a NaOH aqueous solution (25 kg / m ³ ), a mixed solution of ethanol and acetone to degrease, and then dioxane was used. After pre-etching, it was roughened by immersing it in a mixed solution of CrO ₃ (300 kg / m ³ ), H ₂ SO ₄ and H ₂ O at 330 K for 5 minutes. Subsequently, treated sensitized reduction with SnCl ₂ solution was treated activated with PdCl ₂ solution. After finishing these series of pretreatments, copper sulfate (0.04 kmol / m ³ ), potassium sodium tartrate (0.18 kmol / m ³ ), NaOH (0.2
5 kmol / m ³ ) and formalin (10 ⁻² m ³ / m ³ ), a Cu thin film was formed by immersing for 30 minutes in a plating bath adjusted to pH 12 and temperature 298K. The film thickness was 0.1 μm.

Next, the resin mold having the concave portion was polished to obtain a resin mold penetrating in the depth direction. Subsequently, the Cu surfaces of the resin mold and the SiC substrate were subjected to sputtering treatment in Ar gas of 5 Pa to etch the surfaces.

The resin type Cu thin film surface and the substrate Cu thin film surface are brought into contact with each other and pressurized at 1 MPa, and then 500 kH at room temperature.
Ultrasonic waves of z were bonded for 1 second to form a resin type laminate. A clean Cu metal surface was visible in the voids of this resin-type laminate.

Nickel sulfamate (450 g / L)
And boric acid (30 g / L), current density 95 mA /
cm ^2, pH 4, over 60 minutes at a temperature 50 ° C., was filled with cast the cavity of the resin-type laminate conductive. After that, the substrate is polished to a predetermined thickness, followed by ashing with oxygen plasma to remove the resin mold on the substrate and dry etching to remove the substrate and the metal thin film.
A Ni-made structure having a size of 0 μm and a height of 60 μm was obtained. It has been found that this structure has sharp edges and is excellent in verticality in the depth direction, which makes it possible to mass-produce metal microstructures having the same shape.

The embodiments and examples disclosed this time must be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

[0051]

According to the present invention, a large amount of metal microstructures having sharp corner edges and excellent verticality in the depth direction can be manufactured. Further, a strong bond between the resin mold and the substrate can be obtained, and the step of removing the adhesive in the pores after forming the resin mold laminate is not required.

[Brief description of drawings]

FIG. 1 is a process diagram schematically showing an embodiment of a method for producing a metal microstructure according to the present invention.

FIG. 2 is a process diagram schematically showing an embodiment of a resin mold manufacturing method.

[Explanation of symbols]

1 metal microstructure, 2 resin type laminated body, 11 substrate,
12,22 resin type, 13 metal thin film, 14 metal layer,
25 Convex part.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tsuyoshi Haga             3-12-1 Koto, Kamigori-cho, Ako-gun, Hyogo             Sumitomo Electric Industries, Ltd. Harima Research Center

Claims (7)

[Claims] 1. A step of forming a metal thin film on a substrate and a resin mold; and a step of contacting the metal thin film on the substrate with the metal thin film on the resin mold to pressurize them in the thickness direction. Manufacture of a metal microstructure comprising the steps of forming a resin-type laminate by destroying and joining the contaminated layer on the surface layer, and forming a metal layer by electroforming in the holes of the resin-type laminate. Method. 2. The method for producing a metal microstructure according to claim 1, wherein the step of forming the metal thin film is performed by any one of vacuum vapor deposition, sputtering, ion plating and chemical vapor deposition. 3. The method for producing a metal microstructure according to claim 1, wherein the step of forming the metal thin film is performed by either electroplating or electroless plating. 4. The production of a metal microstructure according to claim 1, wherein a difference in lattice constant between a metal forming the metal thin film on the substrate and a metal forming the metal thin film on the resin mold is 20% or less. Method. 5. The step of destroying and joining the contaminated layer on the surface layer of the metal thin film to form a resin type laminate is 10 to 10.
The method for producing a metal microstructure according to claim 1, wherein either one of or both of ultrasonic waves at 00 kHz and local heating at 200 ° C. or less are performed. 6. The method for producing a metal fine structure according to claim 1, wherein a difference in lattice constant between a metal forming the metal thin film on the substrate and a metal forming the metal fine structure is 5% or less. 7. The metal constituting the metal thin film on the substrate, wherein the difference in lattice constant between the metal constituting the metal thin film on the substrate and the metal constituting the metal thin film on the resin mold is 20% or less. The method for producing a metal fine structure according to claim 1, wherein a difference in lattice constant between the metal constituting the metal fine structure and the metal is 5% or less.