JP2015183190A - Production method of metal film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of a metal film capable of patterning the metal film without etching it.SOLUTION: A production method of a metal film 10 has steps for: forming a coating film of a photoresist on a substrate 11; forming a patterned resist layer 12 by forming a pattern on the coating film of the photoresist; and forming the metal film 10 having a thickness of 20 nm or less on the patterned resist layer 12, or between the pattern of the resist layer 12.

Description

  The present invention relates to a method of manufacturing a metal film capable of desired patterning.

  As a conventional method for producing a metal film, after forming a metal film, patterning is performed using a wet process (see, for example, Patent Document 1). In patterning a metal film using a wet process, first, a metal film is formed on the entire surface of a substrate. Next, a resist layer is formed on the entire surface of the metal film. Then, a desired pattern is formed on the formed resist layer using photolithography. Next, along the resist layer pattern, the metal film is removed by wet etching to form a metal film pattern.

Further, a method of patterning using a laser after forming a metal film has been proposed (see, for example, Patent Document 2). In patterning a metal film using a laser, first, a metal film is formed on the entire surface of a substrate. Next, the metal film is removed by scanning using an yttrium / aluminum / garnet (YAG) laser or an yttrium / vanadium oxide (YVO ₄ ) laser to form a metal film pattern.

JP 2007-22730 A JP 2010-87204 A

  However, in the etching by the wet process, if the metal film is thinly formed to about 20 nm, the metal film is damaged by the stress when the resist layer is cured. Further, the metal film is damaged by a solution such as an alkaline aqueous solution used for removing the resist layer during pattern formation, and the performance of the metal film is deteriorated.

In patterning using a laser, there is a problem that particles of a metal material removed by the laser contaminate the substrate. Then, since the particles contaminate the substrate, a cleaning process is necessary. For this reason, damage to the metal film due to cleaning is inevitable.
Furthermore, the patterning pattern is limited due to the laser spot diameter.

  In order to solve the above-described problems, the present invention provides a method for producing a metal film that can be patterned without etching the metal film.

  The metal film manufacturing method of the present invention includes a step of forming a photoresist coating film on a substrate, a step of forming a patterned resist layer by forming a pattern on the photoresist coating film, and a patterning process. Forming a metal film having a thickness of 20 nm or less on the resist layer and between the patterns of the resist layer.

According to the method for producing a metal film of the present invention, after forming a resist layer in a pattern, the metal film is formed, whereby the continuity in the surface direction of the metal film is hindered by the step of the resist layer. Independent metal films can be formed on the layer and between the patterns of the resist layer.
Therefore, the metal film pattern can be formed without performing the etching step after forming the metal film. Therefore, the metal film can be patterned without etching the metal film, and damage to the metal film due to the etching process can be prevented.
Further, by omitting the processing such as the etching process of the metal film, the surface of the metal film is kept clean, so that the cleaning can be omitted.

  According to the present invention, a patterned metal film can be provided without etching the metal film.

It is a figure which shows schematic structure of the metal film manufactured by embodiment of the manufacturing method of a metal film. It is a figure for demonstrating the manufacturing process of a metal film. It is a figure for demonstrating the manufacturing process of a metal film. It is a figure for demonstrating the manufacturing process of a metal film. It is a figure for demonstrating the manufacturing process of a metal film. It is a figure for demonstrating the modification of the manufacturing method of a metal film.

Hereinafter, although the example of the form for implementing this invention is demonstrated, this invention is not limited to the following examples.
The description will be given in the following order.
1. Embodiment 2 of manufacturing method of metal film Modified example

<1. Embodiment of Metal Film Manufacturing Method>
Hereinafter, specific embodiments of the metal film manufacturing method of the present invention will be described.
In FIG. 1, the schematic block diagram (cross section) of the metal film manufactured by the manufacturing method of the metal film of this embodiment is shown.

As shown in FIG. 1, the metal film 10 is formed on the resist layer 12 and the optical adjustment layer 13 on the substrate 11.
The resist layer 12 has a desired pattern on the substrate 11. Examples of this pattern include a pattern when the metal film 10 is used for an electrode or wiring of an electronic device, a pattern used for a transparent electrode such as a touch panel, and the like.
Then, after the resist layer 12 is patterned, the optical adjustment layer 13 and the metal film 10 are formed, whereby the continuity in the surface direction of the optical adjustment layer 13 and the metal film 10 is caused by the steps of the patterned resist layer 12. Thus, the optical adjustment layer 13 and the metal film 10 can be separated along the pattern of the resist layer 12. Therefore, a desired pattern is formed on the optical adjustment layer 13 and the metal film 10 along the pattern of the resist layer 12.
Hereinafter, a method for manufacturing the metal film shown in FIG. 1 will be described.

[Preparation of substrate]
First, the substrate 11 is prepared. There are no particular limitations on the type of the substrate 11 such as glass or plastic. When light is extracted from the substrate side, the substrate 11 is preferably transparent.

  Examples of the transparent substrate 11 preferably used include glass, quartz, and a transparent resin film. A particularly preferable substrate 11 is a resin film having flexibility that can be manufactured by a roll-to-roll method.

  Examples of the resin film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate (TAC), cellulose acetate butyrate, cellulose acetate propionate ( CAP), cellulose esters such as cellulose acetate phthalate, cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide , Polyethersulfone (PES), polyphenylene sulfide, polysulfones Cycloolefin resins such as polyetherimide, polyetherketoneimide, polyamide, fluororesin, nylon, polymethylmethacrylate, acrylic or polyarylate, Arton (trade name, manufactured by JSR) or Appel (trade name, manufactured by Mitsui Chemicals) Can be mentioned.

On the surface of the resin film, a barrier film made of an inorganic film, an organic film, or a hybrid film of both may be formed. The barrier film had a water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) of 0.01 g / (m ² · 24 h) measured by a method according to JIS K 7129-1992. The following barrier films are preferred. Furthermore, the oxygen permeability measured by a method in accordance with JIS K 7126-1987 is 10 ⁻³ ml / (m ² · 24 h · atm) or less, and the water vapor permeability is 10 ⁻⁵ g / (m ² · 24h) The following high-barrier film is preferable.

  As a material for forming the barrier film, any material may be used as long as it has a function of suppressing entry of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like can be used. Furthermore, in order to improve the brittleness of the barrier film, it is more preferable to have a laminated structure of these inorganic layers and layers made of organic materials. Although there is no restriction | limiting in particular about the lamination | stacking order of an inorganic layer and an organic layer, It is preferable to laminate | stack both alternately several times.

  The method for forming the barrier film is not particularly limited. For example, the vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma weight A combination method, plasma CVD method, laser CVD method, thermal CVD method, coating method, or the like can be used. For example, an atmospheric pressure plasma polymerization method as described in JP-A-2004-68143 is preferable.

[Formation of resist layer]
Next, a resist layer 12 is formed on the substrate 11. As shown in FIG. 2, the resist layer 12 is formed by applying a photoresist coating solution on the substrate 11 to form a photoresist coating film 12A. Then, by performing pattern exposure, development, and curing treatment on the formed coating film 12A, a resist layer 12 patterned as shown in FIG. 3 is formed.

(Coating)
A photoresist coating solution is applied onto the substrate 11 to form a photoresist coating film 12A. Photoresist coating is performed using a coating solution obtained by adding a solvent to the photoresist, spray coating method, spin coating method, blade coating method, dip coating method, cast method, roll coating method, bar coating method, die coating method. Etc.
Further, after the photoresist coating film 12A is formed, it is dried to remove the solvent from the coating film 12A.

The thickness of the photoresist coating film 12A is not particularly limited, but the thickness of the resist layer 12 after pattern formation depends on the thickness of the photoresist coating film 12A. For this reason, it is necessary to form the photoresist coating film 12 </ b> A so that the thickness of the resist layer 12 after the pattern formation is at least thicker than the metal film 10.
On the other hand, if it is too thick, there is a possibility that the pattern collapses when a fine pattern is formed on the resist layer 12.

  Therefore, the thickness of the photoresist coating film 12A is preferably formed so that the thickness of the resist layer 12 after pattern formation is 10 nm or more and 30 μm or less. In particular, it is preferably formed so as to be 20 nm or more and 10 μm or less. In the case of using a spin coating method, the film is preferably formed to have a thickness of 100 nm or more, and more preferably 500 nm or more. Moreover, it is preferable to form it so that it may become 3 micrometers or less, and it is still more preferable when considering the material cost side to form so that it may become 1 micrometer or less.

As the photoresist used for coating, a positive type photoresist or a negative type photoresist is used. As the positive photoresist and the negative photoresist, known materials can be used.
Examples of the positive photoresist include JP-A-9-171254, JP-A-5-115144, JP-A-10-87733, JP-A-9-43847, JP-A-10-268512, and JP-A-11-194504. Publication No. 11-223936, No. 11-84657, No. 11-174681, No. 7-285275, JP-A 2000-56452, Pamphlet of International Publication No. 97/39894, No. 98. And positive photosensitive materials described in No./42507 pamphlet and the like.
Examples of the negative photoresist include, for example, JP-A-9-179292, US Pat. No. 5,340,699, JP-A-10-90885, JP-A-2000-321780, 2001-2001. Examples thereof include negative photosensitive materials described in Japanese Patent No. 154374.

  As a solvent for forming a photoresist coating solution, propylene glycol monomethyl ether, propylene glycol monoethyl ether, methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, ethyl cellosolve acetate, dimethylformamide, dimethyl sulfoxide, dioxane, acetone, cyclohexanone, Examples include trichloroethylene and methyl ethyl ketone. These solvents are used alone or in admixture of two or more.

In particular, it is preferable to use an alkali-soluble positive photoresist for forming the resist layer 12. Conventionally known materials can be used as the alkali-soluble positive photoresist.
For example, as an alkali-soluble positive photoresist, a condensate or molecule of an aromatic compound having a phenolic hydroxyl group and formaldehyde such as a cresol novolak resin (preferably a molecule having an acrylic copolymer as a main chain) The structure containing the alkali-soluble organic high molecular polymer which has at least 1 group (for example, a carboxyl group, a phosphoric acid group, a sulfonic acid group etc.) which accelerates | stimulates alkali solubility inside is mentioned. Especially, it is preferable that the organic high molecular polymer which has carboxylic acid in a side chain is included.

  Examples of the alkali-soluble organic polymer include 2-hydroxypropyl (meth) acrylate / polystyrene macromonomer / benzyl methacrylate / methacrylic acid copolymer, 2-hydroxy-3-phenoxypropyl acrylate / polymethyl methacrylate macromonomer. / Benzyl methacrylate / methacrylic acid copolymer, 2-hydroxyethyl methacrylate / polystyrene macromonomer / methyl methacrylate / methacrylic acid copolymer, 2-hydroxyethyl methacrylate / polystyrene macromonomer / benzyl methacrylate / methacrylic acid copolymer, Examples thereof include methacrylic acid copolymers described in JP-A-7-140654.

  As another method for forming a photoresist on the substrate 11, a photoresist forming laminate in which a photoresist is formed on the surface of a transfer base material is prepared separately, and the photoresist layer of the laminate is used as a substrate. 11 for transferring. A commercially available dry film resist can be used as such a laminate.

(exposure)
Next, the photoresist is subjected to pattern exposure by coating.
Pattern exposure is preferable because surface exposure performed through a mask having a desired pattern requires a short time for pattern exposure. In this case, refractive exposure using a lens or reflection exposure using a reflecting mirror may be used, and exposure methods such as contact exposure, proximity exposure, reduced projection exposure, and reflection projection exposure can be used. Further, for example, a method of scanning a laser beam and irradiating only a desired region with the laser beam may be used.
As a light source used for pattern exposure, a light source having an appropriate wavelength is selected in accordance with the spectral sensitivity characteristics of the photosensitive resin composition contained in the photoresist. In general, those containing ultraviolet rays such as g-line, h-line, i-line, and j-line are preferably used. A blue LED may be used.

There is no restriction | limiting in particular as a pattern, According to the objective, it can select suitably. For example, in the patterned resist layer 12, the metal film 10 formed between the patterns of the resist layer 12 can be used as a wiring or an electrode of an electronic device or the like, or the metal film 10 on the patterned resist layer 12. Can be selected without particular limitation, such as a pattern that can be used as a wiring or an electrode of an electronic device, a pattern that can use a part of the metal film 10 as a wiring or an electrode, and the like.
Moreover, there is no restriction | limiting in particular as a magnitude | size of a pattern, Although it can select suitably according to the objective, Any size from nano size to millimeter size may be sufficient.

(developing)
The pattern-exposed photoresist coating film 12A is developed, and a photo corresponding to an exposure area at the time of pattern exposure (when the photoresist is a positive type) or a non-exposed area (when the photoresist is a negative type). The resist coating film 12A is removed, and a resist layer 12 corresponding to the pattern at the time of pattern exposure is formed on the substrate 11.
The development is generally performed by immersing in a developer or showering the developer. A developing solution is used according to the kind of photosensitive resin composition contained in a photoresist.

As the developer, a water-based alkaline developer is suitable. Examples of the aqueous alkaline developer include aqueous solutions of alkali metal salts such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium metasilicate, potassium metasilicate, dibasic sodium phosphate, and tribasic sodium phosphate. , Ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, choline, pyrrole, piperidine, 1 , 8-diazabicyclo- [5,4,0] -7-undecene, 1,5-diazabicyclo- [4,3,0] -5-nonane and other aqueous solutions in which alkaline compounds are dissolved. The density | concentration in the alkaline developing solution of an alkaline compound is 1 mass%-10 mass% normally, Preferably it is 2 mass%-5 mass%.
An organic solvent such as an anionic surfactant, an amphoteric surfactant or alcohol can be added as a developer. As the organic solvent, propylene glycol, ethylene glycol monophenyl ether, benzyl alcohol, n-propyl alcohol, or the like can be used.

(Curing treatment)
Next, after a pattern is formed by development, post baking (heat treatment) is performed to cure the photoresist. The temperature of the heat treatment is set according to the photoresist to be used, for example, about 100 ° C. to 150 ° C.
The photoresist is cured by heat treatment to form the patterned resist layer 12 shown in FIG.

  The resist layer 12 to be formed preferably has a side wall angle (θ in FIG. 3) of 90 ° or more with respect to the surface (bottom surface) in contact with the substrate 11. That is, the resist layer 12 is preferably formed in a tapered shape in which the area of the surface (bottom surface) in contact with the substrate 11 is smaller than the surface (upper surface) opposite to the substrate 11 as shown in FIG.

  When the tapered resist layer 12 is formed, the angle between the substrate 11 and the resist layer 12 (θ in FIG. 3) is preferably greater than 90 ° and less than 180 °. More preferably, it is preferably 95 ° or more, and more preferably 110 ° or more. Further, the angle (θ in FIG. 3) between the substrate 11 and the resist layer 12 is preferably 135 ° or less, and more preferably 120 ° or less.

As shown in FIG. 3, in order to easily form a tapered resist layer 12 whose surface (bottom surface) area in contact with the substrate 11 is smaller than the surface (upper surface) on the opposite side of the substrate 11, a positive type is used as a photoresist. It is preferable to use a photoresist.
Normally, when exposure is performed using a light shielding mask, light passing through the opening of the exposure mask is transmitted while being diffused by the photoresist coating film 12A. For this reason, the area exposed on the bottom surface side (substrate side) is larger than the upper surface side (light shielding mask side) of the coating film 12A.
Therefore, when a positive photoresist is used, the portion that is exposed and removed during development is larger on the bottom side than the top surface side of the photoresist coating film 12A, as shown in FIG. The tapered resist layer 12 having a small area on the bottom surface side and a large area on the top surface side can be easily formed.

  On the other hand, when a negative photoresist is used, unlike the positive type, the resist layer 12 having a small top surface and a large bottom surface is likely to be formed. For this reason, when using a negative photoresist, it is preferable to form the side wall of the resist layer 12 close to the vertical. Further, by utilizing the absorption and diffusion of light in the photoresist coating film 12A, the photoresist material and coating conditions so that the top surface is large and the bottom surface is small like the positive photoresist. It is preferable to adjust the exposure conditions and the like.

  The resist layer 12 may have any shape as long as the metal film 10 formed between the patterns of the resist layer 12 and the metal film 10 formed on the resist layer 12 are separated from each other. However, the present invention is not limited to this, and other shapes can be used. For example, if the upper surface of the resist layer 12 has a shape that inhibits film growth on the side wall of the resist layer 12, growth of the metal film 10 on the side wall of the resist layer 12 can be inhibited. For this reason, at least a part of the sidewall of the resist layer 12 is hidden when viewed from the upper surface side of the resist layer 12, that is, the area of the cross section in the substrate surface direction of the resist layer 12 is smaller than the area of the upper surface of the resist layer 12. If the shape has a portion, the growth of the metal film 10 on the side wall of the resist layer 12 is inhibited, and the metal film 10 can be patterned.

The resist layer 12 is preferably made of a sufficiently transparent material so as not to hinder the transparency of the metal film 10. The resist layer 12 preferably has an average transmittance of light having a wavelength of 450 nm to 800 nm of 50% or more. More preferably, it is 70% or more, More preferably, it is 80% or more.
Also, the admittance between the substrate 11 and the metal film 10 (between the substrate 11 and the metal film 10) and between the substrate 11, the resist layer 12 and the metal film 10 (between the substrate 11 / resist layer 12 / the metal film 10). The difference in admittance is preferably 0.1 or less. By reducing the difference in admittance between the metal film 10 formed on the substrate 11 through the resist layer 12 and the metal film 10 formed on the substrate 11 without through the resist layer 12, the resist layer The deterioration of the visibility due to the formation of 12 can be suppressed.

[Formation of optical adjustment layer]
Next, as shown in FIG. 4, the optical adjustment layer 13 is formed on the entire surface of the resist layer 12 on which the pattern has been formed and on the substrate 11 exposed between the patterns of the resist layer 12.

  The optical adjustment layer 13 is formed on the patterned resist layer 12 and on the substrate 11 exposed between the patterns of the resist layer 12 by a vapor phase deposition method capable of forming a film with high anisotropy. It is formed using highly anisotropic film forming conditions.

At this time, the step in the patterned resist layer 12 prevents continuity in the surface direction of the optical adjustment layer 13, and the optical adjustment layer 13 is separated along the pattern of the resist layer 12. For this reason, the optical adjustment layer 13 is separated along the patterned resist layer 12, and the optical adjustment layer 13 is patterned.
At this time, since the angle of the side wall of the resist layer 12 is 90 ° or more, a highly anisotropic film is formed, and as shown in FIG. In addition, the independent optical adjustment layers 13 can be easily formed.

As a highly anisotropic film-forming method, a known vapor-phase film-forming method can be used. For example, the optical adjustment layer 13 such as a vacuum deposition method, a sputtering method, an ion plating method, a plasma CVD method, a thermal CVD method, etc. From the viewpoint of increasing the refractive index (density), it is preferable to form by an electron beam evaporation method or a sputtering method. In the case of the electron beam evaporation method, it is desirable to have assistance such as IAD (ion assist) in order to increase the film density.
By applying the film forming method under highly anisotropic conditions, the optical adjustment layer 13 does not go around the side surface of the resist layer 12 but is separated along the pattern of the resist layer 12 having the configuration shown in FIG. The optical adjustment layer 13 can be formed.

  The optical adjustment layer 13 is a layer provided for adjusting optical characteristics such as reflectance and transmittance of the metal film 10. By forming the optical adjustment layer 13, the intrinsic absorption and reflectance of the metal film 10 can be adjusted to suppress reflection and improve light transmittance.

  Further, by forming the optical adjustment layer 13, the admittance between the substrate 11 and the metal film 10 (between the substrate 11 and the metal film 10) and between the substrate 11, the resist layer 12 and the metal film 10 (the substrate 11). / Resist layer 12 / metal film 10) is preferably 0.1 or less. By reducing the difference in admittance between the metal film 10 formed on the substrate 11 through the resist layer 12 and the metal film 10 formed on the substrate 11 without through the resist layer 12, the resist layer The deterioration of the visibility due to the formation of 12 can be suppressed.

The optical adjustment layer 13 preferably has a higher refractive index than the substrate 11 and the resist layer 12.
The refractive index of the optical adjustment layer 13 is preferably 1.8 or more, and more preferably 2.1 or more and 2.5 or less. When the refractive index of the optical adjustment layer 13 is higher than 1.8, the light transmittance of the metal film 10 is likely to increase. Further, the refractive index of the optical adjustment layer 13 is preferably 0.1 to 1.1 or more, and more preferably 0.4 to 1.0 or more, greater than the refractive index of the substrate 11. The refractive index of the optical adjustment layer 13 is a refractive index of light having a wavelength of 510 nm, and is measured by an ellipsometer. The refractive index of the optical adjustment layer 13 is adjusted by the material constituting the optical adjustment layer 13, the density of the material in the optical adjustment layer 13, and the like.

The optical adjustment layer 13 is preferably a layer containing a dielectric material or an oxide semiconductor material. The material constituting the optical adjustment layer 13 is preferably a metal oxide or a metal sulfide. Examples of the metal oxide or metal sulfide include titanium oxide (TiO ₂ : n = 2.1 to 2.4), indium tin oxide (ITO: n = 1.9 to 2.2), zinc oxide (ZnO : N = 1.9 to 2.0), zinc sulfide (ZnS: n = 2.0 to 2.2), niobium oxide (Nb ₂ O ₅ : n = 2.2 to 2.4), zirconium oxide ( ZrO ₂ : n = 2.0.-2.1), cerium oxide (CeO ₂ : n = 1.9-2.2), tantalum pentoxide (Ta ₂ O ₅ : n = 1.9-2.2) ), Tin oxide (SnO ₂ : n = 1.8 to 2.0) and the like, and TiO ₂ and Nb ₂ O ₅ are preferable from the viewpoint of refractive index and productivity. The optical adjustment layer 13 may include only one type of dielectric material or oxide semiconductor material, or may include two or more types.

  In addition to the high refractive index layer, a layer having a lower refractive index than the high refractive index layer (low refractive index layer) can be provided as the optical adjustment layer 13. It is also possible to have a structure in which a plurality of high refractive index layers and low refractive index layers are stacked.

  The thickness of the optical adjustment layer 13 is preferably 10 to 150 nm, and more preferably 20 to 80 nm. If the thickness of the optical adjustment layer 13 is less than 10 nm, it is difficult to sufficiently increase the light transmittance of the metal film 10. On the other hand, when the thickness of the optical adjustment layer 13 exceeds 150 nm, the transparency (antireflection property) of the metal film 10 does not increase. The thickness of the optical adjustment layer 13 is measured with an ellipsometer.

[Metal film formation]
Next, as shown in FIG. 5, the metal film 10 is formed on the entire surface of the optical adjustment layer 13.
Similar to the optical adjustment layer 13 described above, the metal film 10 is anisotropically formed on the optical adjustment layer 13 in the patterned resist layer 12 and the substrate 11 exposed from between the patterns of the resist layer 12. It is formed using a vapor phase film forming method capable of high film formation and a film forming condition having high anisotropy.

At this time, the step in the patterned resist layer 12 prevents continuity in the surface direction of the metal film 10, and the metal film 10 is separated along the pattern of the resist layer 12. Therefore, the metal film 10 is separated along the patterned resist layer 12, and the metal film 10 is patterned.
At this time, since the angle of the side wall of the resist layer 12 is 90 ° or more, as shown in FIG. 5, the optical adjustment layer 13 on the resist layer 12 and the substrate 11 is formed by performing highly anisotropic film formation. In addition, independent metal films 10 can be easily formed.

Examples of the method for forming the highly anisotropic metal film 10 include a method using a dry process such as a vapor deposition method (resistance heating, EB method, etc.), a sputtering method, a CVD method, or the like. Of these, the vapor deposition method is preferably applied.
By applying the above method under highly anisotropic conditions, the metal film 10 having the configuration shown in FIG. 5 can be formed without the metal film 10 going around the side surface of the resist layer 12.
In addition, the metal film 10 has sufficient conductivity even if there is no high-temperature annealing after formation, but may be subjected to high-temperature annealing after formation if necessary.

  The metal contained in the metal film 10 is not particularly limited, and for example, silver, copper, gold, platinum group, aluminum, titanium, magnesium, calcium, chromium, or the like can be used. The metal film 10 may contain only one kind of these metals or two or more kinds.

The metal film 10 is preferably a layer composed mainly of silver or silver (Ag) from the viewpoint of low intrinsic absorption and high electrical conductivity. The alloy mainly composed of silver (Ag) constituting the metal film 10 is preferably an alloy containing 50% by mass or more of silver. Examples of the alloy mainly composed of silver include silver magnesium (AgMg), silver copper (AgCu), silver palladium (AgPd), silver palladium copper (AgPdCu), and silver indium (AgIn).
The metal film 10 as described above may have a configuration in which silver or an alloy layer mainly containing silver is divided into a plurality of layers as necessary.

  The metal film 10 preferably has a thickness in the range of 3 to 20 nm. A thickness of 20 nm or less, particularly 12 nm or less, is preferable because the absorption component or reflection component of the layer is kept low and the light transmittance of the metal film 10 is maintained. In addition, the metal film 10 is ensured to have conductivity if it has a thickness of at least 3 nm.

  The metal film 10 preferably has an average transmittance of 50% or more for light having a wavelength of 450 nm to 800 nm in a state where the optical adjustment layer 13 is provided. More preferably, it is 70% or more, More preferably, it is 80% or more. On the other hand, the average reflectance of light having a wavelength of 500 nm to 700 nm of the metal film 10 including the optical adjustment layer 13 is preferably 20% or less, more preferably 15% or less, and further preferably 10% or less. . When the average transmittance of light having the above wavelength is 50% or more and the average reflectance is 20% or less, the metal film 10 can also be applied to applications that require high transparency.

  Through the above steps, as shown in FIG. 5, on the substrate 11 (hereinafter, on the substrate or between the patterns of the resist layer) via the optical adjustment layer 13 or on the resist layer 12 via the optical adjustment layer 13. The metal film 10 can be formed (hereinafter, on the resist layer). If necessary, after forming the metal film 10, a protective film for protecting the metal film 10 may be provided on the entire surface of the substrate 11 on which the metal film 10 is formed.

  The metal film 10 may be a continuous film on the substrate 11 or the resist layer 12 and may have defects such as holes. The portions used for electrodes, wirings and the like need to be formed continuously, but may have defects such as holes as long as sufficient conductivity can be secured. The part used for the electrode, the wiring, or the like may be a continuous film or a film having a discontinuous part such as a sea-island structure.

According to the manufacturing method of the metal film 10 described above, since the metal film 10 on the resist layer 12 and the metal film 10 on the substrate 11 can be completely separated by the resist layer 12, the resist layer 12 is peeled off. Even if not, the metal film 10 on the resist layer 12 or on the substrate 11 (between the patterns of the resist layer 12) can be used independently.
Therefore, the metal film 10 can be patterned without etching the metal film 10.

  Further, according to the above-described method for producing a metal film, the pattern of the metal film 10 can be completely separated by the resist layer 12, so that the resist layer 12 or the resist can be removed without peeling off the resist layer 12. The metal film 10 between the patterns of the layer 12 can be used independently. For this reason, after the metal film 10 is formed, the process can proceed to the next process without the resist layer 12 peeling process. Therefore, damage to the metal film 10 due to an etching solution or the like in the resist layer 12 peeling step can be eliminated, and performance degradation of the metal film 10 can be eliminated.

Further, the pattern of the metal film 10 and the optical adjustment layer 13 depends on the pattern of the resist layer 12. For this reason, it is necessary to pattern the resist layer 12 according to the desired pattern of the metal film 10.
The pattern of the metal film 10 is formed so that either the metal film 10 formed between the patterns of the resist layer 12 or the metal film 10 formed on the resist layer 12 can be selected and used. There is a need to. For example, a pattern using only the metal film 10 formed on the substrate 11 or a pattern using only the metal film 10 formed on the resist layer 12 may be used. Furthermore, it is good also as a pattern which uses the metal film 10 of both on the board | substrate 11 and the resist layer 12. FIG. Alternatively, only a part of the metal film 10 on the substrate 11 or only a part of the metal film 10 on the resist layer 12 may be arbitrarily selected from these combinations.

For example, when the substrate 11 on which the metal film 10 is formed is wound in a roll shape, the resist layer 12 serves as a spacer and does not contact the back surface of the upper substrate 11 on which the metal film 10 on the substrate 11 is wound. For this reason, the metal film 10 on the substrate 11 is not damaged by winding. Therefore, in such a case, it is preferable to use the metal film 10 formed on the substrate 11.
On the other hand, since the resist layer 12 acts as a planarizing layer on the substrate 11, it is easier to form the metal film via the resist layer 12 than to form the metal film 10 directly on the substrate 11. 10 is improved, and the characteristics of the metal film 10 are easily improved.

<2. Modification>
Next, a modification of the metal film manufacturing method described in the above embodiment will be described. FIG. 6 shows a schematic configuration (cross section) of a metal film manufactured according to the modification.

  As shown in FIG. 6, the metal film 10 is formed on the substrate 11 and the substrate 11 via the resist layer 12. This is a configuration obtained by removing the optical adjustment layer 13 from the configuration illustrated in FIG. 1 in the above-described embodiment.

The metal film 10 is formed when a sufficient level difference remains between the patterned resist layer 12 and the pattern of the resist layer 12 in a step after the resist layer 12 is patterned. By forming the metal film 10 in a state where there is a step due to the pattern of the resist layer 12, the pattern of the resist layer 12 can be transferred to the metal film 10 to form the pattern of the metal film 10.
Therefore, as in the configuration shown in FIG. 6, the metal film 10 can be formed immediately after the resist layer 12 is patterned.

In addition, an underlayer for improving the film formation of the metal film 10 and other layers can be formed between the step of forming the resist layer 12 and the step of forming the metal film.
In addition, other layers can be formed on the substrate 11 before the resist layer 12 is formed on the substrate 11.
As described above, if the metal film 10 is formed in a state in which a step due to the pattern of the resist layer 12 is maintained in a step after the pattern formation of the resist layer 12, the pattern formation step of the resist layer 12 or the metal film 10 is performed. It is possible to add an arbitrary process other than the forming process.

  The present invention is not limited to the configuration described in the above-described embodiment, and various modifications and changes can be made without departing from the configuration of the present invention.

  10 metal film, 11 substrate, 12 resist layer, 12A coating film, 13 optical adjustment layer

Claims (7)

Forming a photoresist coating film on the substrate;
Forming a pattern on the photoresist coating film to form a patterned resist layer;
Forming a metal film having a thickness of 20 nm or less on the patterned resist layer and between the patterns of the resist layer.   The method for producing a metal film according to claim 1, further comprising a step of forming an optical adjustment layer after forming the pattern of the resist layer.   The manufacturing method of the metal film of Claim 1 or 2 in which the said metal film contains 1 or more types chosen from silver, copper, gold | metal | money, aluminum, titanium, magnesium, and calcium.   The method for producing a metal film according to claim 1, wherein the resist layer is formed using a positive resist.   The method for producing a metal film according to claim 1, wherein the resist layer is formed in a shape having a smaller area in contact with the substrate than a surface on which the metal film is formed.   The method for producing a metal film according to claim 5, wherein an angle between the substrate contact surface and the side surface of the resist layer is 90 ° or more and less than 180 °.   The admittance between the substrate and the metal film, and the admittance between the substrate, the resist layer, and the metal film, the difference in admittance is 0.1 or less. Production method.

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