TWI627044B - Production method of metal part - Google Patents

Abstract

In the method of manufacturing a metal part by electroforming, even if the scale of the uneven pattern is fine, the metal part can be peeled off without pattern defects. On the surface of the template having a fine concavo-convex pattern on the surface, a release layer is formed along the concavo-convex pattern, an initial layer having conductivity is formed on the release layer, and a metal material is electroformed on the initial layer to form a metal layer. The composite in which the initial layer and the metal layer are integrated is peeled off from the template in an organic solvent to produce a metal part such as a metal mold. In this case, when the height of the concave-convex pattern is H μm and the density of the concave-convex pattern is N/μm ² , the viscosity of the organic solvent at 35 ° C is ηmPa. s satisfies Equations 1 and 2. η<0.9...form 1 η×H×N<1.6...form 2

Description

Method of manufacturing metal parts

The present invention relates to a method of manufacturing a metal part having a specific concave-convex pattern on a surface.

As a method of manufacturing a metal part (for example, a metal mold or a nanoimprint mold), it is known to use a metal template (or master) to deposit a metal material out of a concave-convex pattern surface of a template by electroforming. And a method of peeling off the metal material from the template. In the method of manufacturing a metal part as described above, it has been previously proposed to peel a metal part as an electroformed metal material from a stencil without damaging the uneven pattern.

For example, Patent Document 1 and Patent Document 2 disclose a method of producing a metal part having both conductivity and mold release property by forming an initial layer for conducting electricity containing Ni on the uneven pattern surface of the template before the electroforming step.

Further, for example, Patent Document 3 discloses a method of producing a metal part which improves mold release property by providing a release layer containing a fluorine compound on a concave-convex pattern surface of a template.

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2009-134793

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2010-73272

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2012-56246

However, in the prior method, there is a problem that as the scale of the concavo-convex pattern becomes fine, it becomes difficult to peel off, and the metal part cannot be peeled off without pattern defects as the case may be.

The present invention has been made in view of the above problems, and an object of the invention is to provide a method for producing a metal part in which a metal part is peeled off without pattern defects even in a method of manufacturing a metal part by electroforming.

In order to solve the above problems, a method for producing a metal component according to the present invention is a method of forming a release layer along a concave-convex pattern on the surface of a template having a fine uneven pattern on a surface thereof, and forming a conductive layer on the release layer. The initial layer is formed by electroforming a metal material on the initial layer to form a metal layer, and the composite body in which the initial layer and the metal layer are integrated is peeled off from the template in an organic solvent, thereby manufacturing a metal part of the composite as a template, and The method for producing a metal component is characterized in that the viscosity of the organic solvent at 35 ° C is ηmPa when the height of the concave-convex pattern is H μm and the density of the concave-convex pattern is N/μm ² . s satisfies Equation 1 and Equation 2: η < 0.9... Equation 1

η × H × N < 1.6... Formula 2.

Further, in the method for producing a metal part according to the present invention, it is preferable that the viscosity ratio η satisfies the formula 3: η < 0.6 (Formula 3).

Further, in the method for producing a metal part according to the present invention, it is preferable that the viscosity ratio η satisfies the formula 4: η × H × N < 1.0 (Formula 4).

Further, in the method for producing a metal part according to the present invention, at least one of methanol, octane and hexane is preferably used as the organic solvent, and the organic solvent is particularly preferably octane or hexane.

Further, in the method for producing a metal part according to the present invention, the temperature of the organic solvent is preferably within a range of ±15 ° C based on the temperature of the electroforming solution used in the electroforming step.

The method for producing a metal part of the present invention is particularly effective in that an organic solvent having a viscosity lower than water (viscosity: 0.9 mPa·s) and satisfying η × H × N < 1.6 is used as a stripping liquid, and in the organic solvent The metal part is peeled off from the stencil, so the stripping liquid easily enters the gap between the metal part and the stencil compared to the pure water used previously. As a result, in the method of manufacturing a metal part by electroforming, even if the scale of the uneven pattern is fine, the metal part can be peeled off without pattern defects.

10‧‧‧Metal mold

12‧‧‧metal layer

14‧‧‧ initial layer

16‧‧‧ release layer

20‧‧‧ template

Fig. 1 is a schematic cross-sectional view showing a procedure of a method of manufacturing a metal component according to an embodiment.

Hereinafter, the embodiment of the present invention will be described using the drawings, but the present invention is not limited to the embodiment. In addition, in order to make it easy to visually recognize, the scale of each component in the drawing and the like are appropriately different from those of the actual person.

In the following description, a case where a metal mold (also referred to as a master mold or the like) used in, for example, a nanoimprint method is manufactured as a metal member will be described.

Fig. 1 is a schematic cross-sectional view showing the procedure of a method of manufacturing a mold according to the embodiment. The method for producing a mold according to the present embodiment is a method of first preparing a template 20 (a of FIG. 1), and forming a release layer 16 along the surface of the template 20 having a fine uneven pattern on the surface (Fig. b) of 1), a conductive initial layer 14 is formed on the release layer 16 (c of FIG. 1), and a metal material is electroformed on the initial layer 14 to form a metal layer 12 (d of FIG. 1), which will initially The composite in which the layer 14 and the metal layer 12 are integrated is peeled off from the stencil 20 in an organic solvent (e of FIG. 1), and the metal mold 10 as a composite of the stencil 20 is produced, and the height of the concave-convex pattern is set to H μm and When the density of the concave-convex pattern is N/μm ² , the viscosity of the organic solvent at 35 ° C is ηmPa. s satisfies the following formulas 5 and 6.

η<0.9...式5

η×H×N<1.6...form 6

Thereby, the metal mold 10 which is a composite body which has the template 20 as a master and has the reverse pattern of the uneven pattern of the template 20 is obtained. That is, the metal mold 10 manufactured in the present embodiment includes the metal layer 12, the initial layer 14, and the release layer 16. Further, since the release layer 16 contains an organic material, some or all of the release layer 16 may remain on the template side during the peeling step.

The material of the template 20 to be the master is not particularly limited, and examples thereof include metals such as Ni, Ni-P, Ni-B, Ti, and W, inorganic oxides such as cerium oxide, glass such as quartz glass, and acrylic resins. Any of resins such as styrene resins. However, it is necessary to be insoluble in the organic solvent used. The template 20 has a concavo-convex pattern (more precisely, a reverse pattern thereof) to be transferred onto the metal mold 10. The shape of the convex portion or the concave portion of the concave-convex pattern is appropriately designed into a polygonal column shape, a polygonal pyramid shape, a cylindrical shape, a conical shape, a dome shape, or the like. The width of the convex portion or the concave portion in the plan view is, for example, 10 nm to 10 μm, the height or the depth is, for example, 10 nm to 10 μm, and the interval between the convex portions or the concave portions is, for example, 10 Nm~10μm. Further, in the present invention, the width of the convex portion or the concave portion in the plan view is 10 nm to 1 μm, the height or depth is 10 nm to 1 μm, and the interval between the convex portions or the concave portions is 10 nm to 1 μm as compared with the conventional peeling liquid (pure water). The situation is particularly effective. Such a template 20 having a concavo-convex pattern can be produced, for example, by forming a resist film on the surface of a substrate which is the basis of the template, and resisting it by photolithography or electron beam lithography The film is patterned and the patterned resist film is then etched as a mask. Further, the template 20 can also be fabricated by disposing a mask material on the surface of the substrate by a self-organization technique and then performing etching.

In the release layer forming step, the release layer 16 for easy peeling from the template 20 of the metal mold 10 is formed. The release layer 16 is not particularly limited. For example, the release layer 16 may be a molecular film containing an organic material such as a decane coupling agent. As the decane coupling agent, for example, a decane coupling agent having an aromatic ring and further having an amine group, a sulfur group or a hydroxyl group is preferable. The decane coupling agent having both an aromatic ring and an amine group is, for example, triethoxy[2-(phenylamino)methyl]decane, trimethoxy[3-(phenylamino)propyl]decane. The decane coupling agent having both an aromatic ring and a sulfur group is, for example, 2-(3-trimethoxydecylpropylthio)thiophene. The decane coupling agent having both an aromatic ring and a hydroxyl group is, for example, 2-hydroxy-4-(3-triethoxydecylpropoxy)diphenyl ketone. By the presence of an aromatic ring, the mold release property is improved, and an initial layer can be formed by the presence of an amine group, a sulfur group or a hydroxyl group.

Such a molecular film is formed, for example, by surface treatment using a release agent containing a decane coupling agent. As the method of the surface treatment, any of known methods such as a vapor phase method, a dipping method, a coating method, and a spray method can be used. For example, the release layer 16 formed by surface treatment using a decane coupling agent is a monomolecular film or a thin film close to a monomolecular film. The film has a film thickness of several Å to several tens of Å. Therefore, such a release layer 16 has extremely high followability to the shape of the uneven pattern of the template 20.

In the initial layer forming step, the initial layer 14 is formed as an energized film for performing electroforming. The method for forming the initial layer 14 is not particularly limited, and may be a dry process such as a sputtering method or a wet process such as electroless plating.

When electroless plating is used, the release layer 16 is supplied with an electroless plating catalyst in advance. The catalyst supply liquid is appropriately selected depending on the material to be deposited by electroless plating (that is, the material of the initial layer 14). In particular, as described above, when the release layer 16 has an amine group, a sulfur group or a hydroxyl group, the release layer 16 has good catalyst adsorption property (the property of adsorbing metal ions which become a catalyst), and the catalyst can be confirmed. Precipitate. Thereby, the initial layer 14 can be formed by electroless plating in consideration of the precipitated catalyst (metal). The method of supplying the catalyst to the release layer 16 and the subsequent electroless plating is not particularly limited, and it can be carried out by a known method. For example, the catalyst is supplied by a known method such as a dipping method using a catalyst supply liquid, a coating method, and a spray method, and as a result, the desired catalyst (Pd, Ag, Cu, Ni is supplied to the release layer 16). Wait). Further, the electroless plating is carried out, for example, by a known plating bath such as a method of immersing a template 20 in which a catalyst is supplied in a plating bath filled with a plating solution. As described above, when the initial layer 14 is formed by the supply of the catalyst and the electroless plating, the large-scale apparatus and the film formation are not required as compared with the case where the initial layer 14 is formed by a special film formation method such as vacuum film formation. The time required is also shorter, so the steps are simple.

The thickness of the initial layer 14 is preferably set in the range of 0.05 μm to 0.5 μm. The reason is that if the thickness of the initial layer 14 is less than 0.05 μm, there is electroforming Further, if the thickness of the initial layer 14 exceeds 0.5 μm, the adhesion failure due to stress may be unsatisfactory.

In the electroforming step, the metal material is deposited on the initial layer 14 by energizing the initial layer 14, and the metal layer 12 is formed on the initial layer 14. The electroforming liquid used for the precipitation of the metal material, or the electroforming conditions such as the liquid temperature, the pH value, the current density, and the energization time are not particularly limited, and the previously known electroforming liquid can be appropriately selected and appropriately selected according to the metal parts to be produced. Set the conditions. Further, examples of the material of the metal material include metals such as Ni, Cr, Cu, a Ni-Cr alloy, a Ni-Fe alloy, and a Ni-W alloy. The thickness of the metal layer 12 is preferably 10 μm or more. The reason is that if the thickness is less than 10 μm, there is a case where the metal mold 10 is broken in the next peeling step, which is not preferable. The temperature of the electroforming is preferably carried out in the range of 25 ° C to 55 ° C. The reason is that if the electroforming temperature is less than 25 ° C, the electroforming time becomes long and the production suitability disappears. Further, when the electroforming temperature exceeds 55 ° C, the dimensional accuracy of the concavo-convex pattern is lowered due to the thermal strain of the template 20 . Poor.

In the peeling step, the metal layer 12, the initial layer 14, and the release layer 16 are peeled off from the template 20 in an organic solvent by an integrator, and as a result, the metal mold 10 is obtained. In the present invention, the metal mold 10 is peeled off from the stencil 20 in an organic solvent having a lower viscosity than the pure water previously used as the mold release liquid. Specifically, the organic solvent to be used is preferably such that when the height of the uneven pattern of the template 20 is H μm and the density of the uneven pattern is N/μm ² , the organic solvent is at 35 ° C. Viscosity rate ηmPa. s satisfies the above formula 1 and formula 2. Here, the "height of the uneven pattern" refers to the height of the convex portion constituting the concave-convex pattern or the average value of the depth of the concave portion (for example, an average value of about 10 points), and the "density of the concave-convex pattern" means The number of the convex portions or the concave portions per 1 μm ² (the total number of convex portions or concave portions divided by the area of the entire pattern region). Further, the viscosity ratio is, for example, an Electro-Magnetically Spinning (EMS) viscometer (Kyoto Electronics Co., Ltd.) under the measurement conditions of a steel ball diameter of 2 mm, a liquid temperature of 35 ° C, and a rotational speed of 1000 rpm. The average value of the three measured values obtained was calculated.

The equation 6 is derived based on the results of the embodiments described later. Further, the formula 6 conceptually indicates that the higher the height of the concave-convex pattern or the higher the density of the concave-convex pattern, that is, the larger the side wall area of the convex portion or the concave portion of the concave-convex pattern, it is preferable to use a lower viscosity ratio. Organic solvents. In the present embodiment, since the organic solvent having a low viscosity ratio which satisfies the above formula 6 is used, and the metal component is peeled off from the template in the organic solvent, the peeling liquid is compared with the pure water (organic The solvent) easily enters the gap between the metal layer 12 and the template 20, and exhibits good mold release property. Therefore, it is possible to manufacture a metal part having a nano-scale fine-shaped portion with high reproducibility. Further, the organic solvent actually enters various gaps between the release layer 16 and the template 20, between the release layer 16 and the initial layer 14, and inside the release layer 16. When η × H × N is 1.6 or more, it is difficult for the organic solvent to enter the gap between the die plate 20 and the mold 10, and it is difficult to peel the metal mold 10 from the die plate 20 (that is, the mold release of the metal mold 10).

The viscosity ratio η of the organic solvent is preferably such that the formula 7 and/or the formula 8 are further satisfied. The reason is that the lower the viscosity ratio, the more the mold release property is improved and the time required for peeling can be shortened.

η<0.6... Equation 7

η×H×N<1.0...8

Further, the temperature of the organic solvent is preferably within a range of ±15 ° C based on the temperature of the electroforming solution used in the electroforming step. The reason is that if the temperature of the organic solvent exceeds the above range, the pattern may be broken due to the difference in linear expansion coefficient between the template 20 and the mold 10. In addition, in the range of ±15 ° C based on the temperature of the electroforming liquid, the viscosity of the organic solvent does not change due to the relationship with the pure water. Further, the temperature of the organic solvent is more preferably within a range of ±10 ° C based on the temperature of the electroforming solution.

As described above, the method of manufacturing the metal part of the present embodiment is particularly It is because an organic solvent having a viscosity lower than water (viscosity of 0.9 mPa·s) and satisfying η×H×N<1.6 is used as a peeling liquid, and the metal part is peeled off from the template in the organic solvent, The stripping liquid easily enters the gap between the metal part and the stencil compared to the pure water previously used. As a result, in the method of manufacturing a metal part by electroforming, even if the scale of the uneven pattern is fine, the metal part can be peeled off without pattern defects. Further, as a result, high-quality metal parts can be manufactured with excellent reproducibility.

[Examples]

The examples of the production method of the present invention are shown below.

<Example 1>

(up to the electroforming step)

First, prepare a circular area of 4 inches in diameter by anisotropic etching or the like. A ruthenium wafer having a diameter of 6 inches which is microfabricated by the following nano pattern is carried out. Further, the pattern pitch is an average of the intervals between the adjacent holes in relation to the arranged holes.

Pattern 1:

Hole shape cylindrical

The depth of the hole is 900nm (H=0.90)

Pattern spacing 1000nm

2.3 holes per 1 μm ² (N=2.3)

H×N=2.070

Then, the patterned surface of the tantalum wafer was subjected to surface activation treatment using a UV-O3 detergent (SEN LIGHT corporation Photo Surface Prices) PL16-110D. Then, a release agent of trimethoxy[3-(phenylamino)propyl]decane (Tokyo Chemical Industry Co., Ltd., P1458) was sealed together with a ruthenium wafer in a volume ratio of 10 mL/L. In a closed container.

Then, the sealed container was placed in an oven and heated at 100 ° C for 2 hours. Then, the germanium wafer is taken out, and the excess mold release agent is removed by a suitable solvent to form a release layer. The tantalum wafer on which the release layer was formed was immersed in a solution of SnCl ₂ (Wako Pure Chemical Industries Co., Ltd., 208-01565) (room temperature) for 1 minute, and washed with water, and then further in PdCl ₂ (Wako Pure Chemical Industries, Ltd.) Co., Ltd., 164-00052) was immersed in a solution (room temperature) for 1 minute and washed with water to provide a catalyst. Then, it contains 0.1M nickel sulfate (Wako Pure Chemical Industries Co., Ltd., 148-0117), 0.2M sodium hypophosphite sodium acetate (Wako Pure Chemical Industries Co., Ltd., 193-02225) and 0.2M ammonium acetate. In the electroless nickel plating solution (50 ° C) of Wako Pure Chemical Industries Co., Ltd., 019-02835, a catalyst-attached ruthenium wafer was immersed for 2 minutes to precipitate nickel (Ni) on the surface of the release layer. Thereby, an energized film containing nickel is formed.

Then, after the silicon wafer on which the current-carrying film was formed was washed with water, the germanium wafer was immersed in a nickel electroforming liquid, and the current-carrying film was energized at a current density of 4 A/dm ² for 150 minutes to precipitate nickel. The final thickness of the electroformed film (metal layer) was 150 μm.

(peeling step)

The four ruthenium wafers obtained in the above step were respectively immersed in water (35° C. at η=0.90 mPa·s), methanol (η=0.55), and octane (η) by a peeling step. In each of the solutions of =0.40) and hexane (η = 0.10), the razor was slid between the template and the metal parts and peeled off.

(evaluation benchmark)

The pattern of the peeled metal parts was observed by an electron microscope, and the peeling result was evaluated based on the following evaluation criteria.

A: The pattern is not damaged and the metal parts can be peeled off within 10 minutes.

B: The pattern is not damaged and the metal parts can be peeled off within 10 minutes to 1 hour.

C: Cannot be peeled off. Or the pattern of the peeled metal part creates damage.

(result)

According to the results described below, in the case of peeling in an organic solvent as compared with the case of peeling in water, even if the scale of the concave-convex pattern is fine, there is no pattern defect. Strip the metal parts.

Water (η=0.90) C

Methanol (η = 0.55) B

Octane (η=0.40) A

Hexane (η=0.10) A

<Example 2>

Four ruthenium wafers which were microfabricated by the following pattern and formed into a nano pattern were formed by peeling off each solution of water, methanol, octane, and hexane, respectively. 1 is the same.

Pattern 2:

Hole shape cylindrical

The depth of the hole is 150nm (H=0.15)

Pattern spacing 100nm

The number of holes per 1 μm ² is 23.1 (N=23.1)

H×N=3.465

(result)

Water (η=0.90) C

Methanol (η = 0.55) C

Octane (η=0.40) B

Hexane (η=0.10) A

<Example 3>

Forming four crystals that have been subjected to microfabrication with the following pattern to form a nano pattern The circle was the same as that of Example 1 except that the peeling step was carried out in each of water, methanol, octane and hexane.

Pattern 3:

Hole shape cylindrical

The depth of the hole is 200nm (H=0.20)

Pattern spacing 100nm

The number of holes per 1 μm ² is 23.1 (N=23.1)

H×N=4.620

(result)

Water (η=0.90) C

Methanol (η = 0.55) C

Octane (η=0.40) C

Hexane (η=0.10) A

<Comparative Example 1>

Four ruthenium wafers which were microfabricated by the following pattern and formed into a nano pattern were formed by peeling off each solution of water, methanol, octane, and hexane, respectively. 1 is the same.

Pattern 4:

Hole shape cylindrical

The depth of the hole is 50nm (H=0.05)

Pattern spacing 1000nm

Pattern spacing 1000nm

2.3 Number of holes (N = 2.3) per 1μm ² of

H×N=0.115

(result)

Water (η=0.90) A

Methanol (η = 0.55) A

Octane (η=0.40) A

Hexane (η=0.10) A

<Comparative Example 2>

Four ruthenium wafers which were microfabricated by the following pattern and formed into a nano pattern were formed by peeling off each solution of water, methanol, octane, and hexane, respectively. 1 is the same.

Pattern 5:

Hole shape cylindrical

The depth of the hole is 50nm (H=0.05)

Pattern spacing 100nm

The number of holes per 1 μm ² is 23.1 (N=23.1)

H×N=1.155

(result)

Water (η=0.90) B

Methanol (η = 0.55) A

Octane (η=0.40) A

Hexane (η=0.10) A

<General Review>

Table 1 is a table summarizing the results of Examples 1 to 3 and Comparative Examples 1 to 2. The number of each result in the table is a value of η × H × N, and A, B or C is the evaluation result.

According to Table 1, when the value of H×N is small (that is, when the height of the concave-convex pattern and/or the density of the concave-convex pattern is small and the concave-convex pattern is relatively large), when peeling in water and peeling in an organic solvent, There is less difference in the ease of peeling. On the other hand, it is understood that when the value of H×N is large (that is, since the height of the concave-convex pattern and/or the density of the concave-convex pattern is large and the concave-convex pattern is relatively fine), the peeling in the organic solvent is more than the peeling in the water. effective. Specifically, when the value of η × H × N is 1.4 or less, the peeling result is A or B, and when the value of η × H × N is 1.8 or more, the peeling result is C. From this, it is considered that if η×H×N<1.6 is taken in the middle, even if the scale of the uneven pattern is fine, the metal part can be peeled off without pattern defects. Further, it can be seen that if η × H × N < 1.0, the time required for mold release of the metal mold can be shortened.

Further, according to Comparative Example 1 and Comparative Example 2, the present invention also has the advantage that even if the concave-convex pattern of a size that can be peeled off in water is released from the mold by using an organic solvent, it can be shortened. The time required for the demolding of the metal mold.

[Industrial availability]

The metal mold manufactured in the present invention can be used, for example, to produce a light-emitting diode-patterned sapphire substrate (Light-Emitting) having a fine structure on the surface of the element and improving the brightness of a light-emitting diode (LED). Nanoimprint dies used in the field of Diode-Patterned Sapphire Substrate, LED-PSS).

In addition, the metal component which can be manufactured by the present invention is not limited to a metal mold, a mold, or the like, and is, for example, a metal component including a nano-scale fine-shaped portion such as a wiring, an electrode, or an image pickup device.

Claims (7)

A method for producing a metal part, which is a method of forming a release layer along the concave-convex pattern on the surface of a template having a fine uneven pattern on a surface, and forming an initial conductive layer on the release layer a layer on which a metal material is electroformed to form a metal layer, and a composite body in which the initial layer and the metal layer are integrated is peeled off from the template in an organic solvent to produce a composite as a template. The metal part of the body, and the method of manufacturing the metal part, characterized in that the organic solvent is used when the height of the uneven pattern is H μm and the density of the uneven pattern is N/μm ² Viscosity ηmPa at 35 ° C. s satisfies Formula 1 and Formula 2: η < 0.9... Formula 1 η × H × N < 1.6... Formula 2. The method for producing a metal part according to claim 1, wherein the viscosity ratio η satisfies Formula 3: η < 0.6 (Formula 3). The method of manufacturing a metal part according to the first aspect of the invention, wherein the viscosity ratio η satisfies the formula 4: η × H × N < 1.0... Equation 4. The method for producing a metal part according to the second aspect of the invention, wherein the viscosity ratio η satisfies the formula 4: η × H × N < 1.0 (Formula 4). The method for producing a metal part according to the first aspect of the invention, wherein the organic solvent is at least one of methanol, octane and hexane. The method for producing a metal part according to claim 5, wherein the organic solvent is octane or hexane. The method for producing a metal part according to any one of claims 1 to 6, wherein the temperature of the organic solvent is based on the temperature of the electroforming solution used in the electroforming step. Within the range of ±15 °C.