JP7310204B2 - Method for forming conductive film, method for manufacturing conductor, method for forming resist pattern - Google Patents

Description

The present invention relates to a method for forming a conductive film, a method for manufacturing a conductor and a method for forming a resist pattern using the method for forming a conductive film.

Pattern formation technology using charged particle beams such as electron beams and ion beams is expected to be the next-generation technology of photolithography. When using a charged particle beam, it is important to improve the sensitivity of the resist layer to improve productivity. For this reason, an acid is generated in the exposed area or the area irradiated with the charged particle beam, followed by a heat treatment called post-exposure bake (PEB), which accelerates the cross-linking reaction or decomposition reaction. A highly sensitive chemically amplified resist. is predominantly used.

By the way, in pattern formation methods using charged particle beams such as electron beams and ion beams, especially when the substrate is insulating, the trajectory of the charged particle beam is bent due to the electric field generated by the charge-up of the substrate. There is a problem that it is difficult to obtain a desired pattern.
As a means for solving this problem, it is effective to apply a conductive composition containing a conductive polymer to the surface of a resist layer to form a conductive film, and to coat the surface of the resist layer with the conductive film. already known.

Exposure (drawing) using charged particle beams such as electron beams and ion beams is performed in a vacuum. Therefore, when the surface of the resist layer is coated with a conductive film, heat treatment is performed during the formation of the conductive film to reduce volatile components such as solvents in order to suppress contamination inside the exposure apparatus.
For example, in Patent Document 1, a conductive composition obtained by dissolving a conductive polymer having an acidic group and a specific water-soluble polymer in water or a mixed solvent of water and isopropyl alcohol is coated on a resist layer and hot. An example in which a conductive film is formed by performing heat treatment at 50 to 150° C. on a plate is described.

Japanese Patent Application Laid-Open No. 2002-226721

The formation of the conductive film may adversely affect the underlying layer of the conductive film. For example, when a conductive film is formed on a chemically amplified resist layer by the method described in Patent Document 1, the resist layer may be thinned.
SUMMARY OF THE INVENTION An object of the present invention is to provide a method of forming a conductive film that has little effect on the underlying layer, a method of manufacturing a conductor using the same, and a method of forming a resist pattern.

The present invention has the following aspects.
[1] A step of applying a conductive composition containing a conductive polymer and a solvent to a surface to be treated to form a coating film; A method for forming a conductive film, comprising a drying step of removing the solvent from the above to form a conductive film.
[2] The method of forming a conductive film according to [1], wherein the coating film is heated to less than 50°C in a reduced pressure atmosphere in the drying step.
[3] The method of forming a conductive film according to [1], wherein the coating film is held in a dry gas atmosphere for 10 minutes or more in the drying step.
[4] The method of forming a conductive film according to any one of [1] to [3], wherein the conductive polymer contains a conductive polymer having an acidic group.
[5] A method for producing a conductor having a base material and a conductive film provided on the base material, wherein the surface of the base material is the surface to be treated, and the steps of [1] to [4] are performed. A method for manufacturing a conductor, comprising forming a conductive film by any one of the methods.
[6] A lamination step of forming a conductive film on a substrate having a resist layer on one side by using the surface of the resist layer as the surface to be processed by any of the methods of [1] to [4], and the resist layer. and an exposure step of patternwise irradiating a charged particle beam from the conductive film side.
[7] The method of forming a resist pattern according to [6], wherein the resist layer is made of a chemically amplified resist.

ADVANTAGE OF THE INVENTION According to this invention, the formation method of a conductive film with little influence on a lower layer, the manufacturing method of a conductor using the same, and the formation method of a resist pattern can be provided.

Embodiments of the present invention will be described below. The following embodiments are merely examples for explaining the present invention, and are not intended to limit the present invention only to these embodiments. The present invention can be implemented in various modes without departing from its spirit.

As used herein, the term “solubility” refers to 10 g of water, water containing at least one of a base and a basic salt, water containing an acid, or a mixture of water and a water-soluble organic solvent (liquid temperature: 25°C). It means that 0.1 g or more is uniformly dissolved in . In addition, "water-soluble" means solubility in water in relation to the above-mentioned solubility.
As used herein, the "terminal" of the "terminal hydrophobic group" means a site other than the repeating units that constitute the polymer.
As used herein, "mass average molecular weight" is a mass average molecular weight (converted to sodium polystyrene sulfonate) measured by gel permeation chromatography (GPC).

In the present invention, “conductivity” means having a surface resistance value of 1×10 ¹¹ Ω/□ or less. The surface resistance value is obtained from the potential difference between the electrodes when a constant current is passed.
The surface resistance value of the conductive film of the present embodiment is 1×10 ¹¹ Ω/□ or less, preferably 1×10 ⁹ Ω/□ or less, and more preferably 1×10 ⁷ Ω/□ or less.

The conductive composition of this embodiment contains a conductive polymer and a solvent. Optional components other than the conductive polymer and solvent may be further included.
<Conductive polymer>
A known conductive polymer can be used. Examples include polypyrrole, polythiophene, polythiophene vinylene, polytelluphene, polyphenylene, polyphenylene vinylene, polyaniline, polyacene, and polyacetylene.
Among these, polypyrrole, polythiophene, and polyaniline are preferable from the viewpoint of excellent conductivity.

The conductive polymer preferably has water solubility or water dispersibility. When the conductive polymer is water-soluble or water-dispersible, the coating property of the conductive composition is enhanced, and a conductor having a uniform thickness can be easily obtained.

The conductive polymer is preferably a conductive polymer having an acidic group (hereinafter also simply referred to as "conductive polymer (A)"). Having an acidic group increases the water solubility.
The acidic group is preferably a sulfonic acid group or a carboxy group. You may have two types of acidic groups in one molecule. Some or all of the acidic groups may form a salt.
As the conductive polymer (A), JP-A-61-197633, JP-A-63-39916, JP-A-1-301714, JP-A-5-504153, JP-A-5-503953, JP-A-4-32848, JP-A-4-328181, JP-A-6-145386, JP-A-6-56987, JP-A-5-226238, JP-A-5-178989, JP-A-H9 6-293828, JP 7-118524, JP 6-32845, JP 6-87949, JP 6-256516, JP 7-41756, JP 7- The conductive polymers disclosed in JP-A-48436, JP-A-4-268331, JP-A-2014-65898, etc. are preferable from the viewpoint of solubility.

The conductive polymer (A) contains one or more monomer units selected from the group consisting of units represented by the following general formulas (1) to (4) from the viewpoint of being able to exhibit high conductivity and solubility, A conductive polymer containing 20 to 100 mol % in all units (100 mol %) constituting the conductive polymer is preferred.

In formulas (1) to (4), X represents a sulfur atom or a nitrogen atom, R ¹ to R ¹⁵ each independently represents a hydrogen atom, a straight or branched alkyl group having 1 to 24 carbon atoms, 1 to 24 linear or branched alkoxy groups, acidic groups, hydroxy groups, nitro groups, halogen atoms (-F, -Cl, -Br or I), -N(R ¹⁶ ) ₂ , -NHCOR ¹⁶ , - represents SR ¹⁶ , —OCOR ¹⁶ , —COOR ¹⁶ , —COR ¹⁶ , —CHO, or —CN; R ¹⁶ represents an alkyl group having 1 to 24 carbon atoms, an aryl group having 1 to 24 carbon atoms, or an aralkyl group having 1 to 24 carbon atoms.
However, at least one of R ¹ and R ² in general formula (1), at least one of R ³ to R ⁶ in general formula (2), and R ⁷ to R ¹⁰ in general formula (3) At least one of them, at least one of R ¹¹ to R ¹⁵ in general formula (4) is an acidic group or a salt thereof.
The acidic group is a sulfonic acid group (sulfo group) or a carboxylic acid group (carboxy group).

In the conductive polymer (A), the sulfonic acid group may exist in an acid state (--SO ₃ H) or in an ionic state (--SO ₃ ⁻ ). The sulfonic acid group also includes a substituent having a sulfonic acid group (--R ¹⁷ SO ₃ H).
Carboxylic acid groups in the conductive polymer (A) may exist in an acid state (--COOH) or in an ionic state ( ^--COO.sup.- ). Carboxylic acid groups also include substituents (-R ¹⁷ COOH) having a carboxylic acid group.
R ¹⁷ is a linear or branched alkylene group having 1 to 24 carbon atoms, a linear or branched arylene group having 1 to 24 carbon atoms, or a linear or branched aralkylene group having 1 to 24 carbon atoms. show.

Salts of acidic groups include alkali metal salts, alkaline earth metal salts, ammonium salts, or substituted ammonium salts of sulfonic acid groups or carboxylic acid groups.
Examples of alkali metal salts include lithium sulfate, lithium carbonate, lithium hydroxide, sodium sulfate, sodium carbonate, sodium hydroxide, potassium sulfate, potassium carbonate, potassium hydroxide and derivatives having these skeletons.
Examples of alkaline earth metal salts include magnesium salts and calcium salts.
Examples of substituted ammonium salts include aliphatic ammonium salts, saturated alicyclic ammonium salts and unsaturated alicyclic ammonium salts.
Examples of aliphatic ammonium salts include methylammonium, dimethylammonium, trimethylammonium, ethylammonium, diethylammonium, triethylammonium, methylethylammonium, diethylmethylammonium, dimethylethylammonium, propylammonium, dipropylammonium, isopropylammonium, diisopropyl ammonium, butylammonium, dibutylammonium, methylpropylammonium, ethylpropylammonium, methylisopropylammonium, ethylisopropylammonium, methylbutylammonium, ethylbutylammonium, tetramethylammonium, tetramethylolammonium, tetraethylammonium, tetra-n-butylammonium, tetra sec-butylammonium, tetra-t-butylammonium and the like.
Saturated alicyclic ammonium salts include, for example, piperidinium, pyrrolidinium, morpholinium, piperazinium and derivatives having these skeletons.
Examples of unsaturated alicyclic ammonium salts include pyridinium, α-picolinium, β-picolinium, γ-picolinium, quinolinium, isoquinolinium, pyrrolinium, and derivatives having these skeletons.

The conductive polymer (A) preferably has a unit represented by the above general formula (4) from the viewpoint of being able to express high conductivity, and among them, from the viewpoint of excellent solubility, the following general formula It is more preferable to have a monomer unit represented by (5).

In formula (5), R ¹⁸ to R ²¹ are each independently a hydrogen atom, a straight or branched alkyl group having 1 to 24 carbon atoms, a straight or branched alkoxy group having 1 to 24 carbon atoms, It represents an acidic group, a hydroxy group, a nitro group, or a halogen atom (-F, -Cl, -Br or I). At least one of R ¹⁸ to R ²¹ is an acidic group or a salt thereof.

As the unit represented by the general formula (5), any one of R ¹⁸ to R ²¹ is a linear or branched alkoxy group having 1 to 4 carbon atoms in terms of ease of production, Preferably any one of the other is a sulfonic acid group and the rest are hydrogen.

The conductive polymer (A), from the viewpoint of excellent solubility in water and organic solvents regardless of pH, among all units (100 mol%) constituting the conductive polymer (A), the general formula (5) It preferably contains 10 to 100 mol %, more preferably 50 to 100 mol %, and particularly preferably 100 mol % of the unit represented by.
Moreover, from the viewpoint of excellent conductivity, the conductive polymer (A) preferably contains 10 or more units represented by the general formula (5) in one molecule.

In the conductive polymer (A), from the viewpoint of further improving the solubility, the number of aromatic rings to which acidic groups are bonded to the total number of aromatic rings in the polymer is preferably 50% or more, and 70% or more. It is more preferably 80% or more, particularly preferably 90% or more, and most preferably 100%.
The number of aromatic rings to which an acidic group is bonded with respect to the total number of aromatic rings in the polymer refers to a value calculated from the charging ratio of the monomers when the conductive polymer (A) is produced.

In the conductive polymer (A), the substituent other than the acidic group on the aromatic ring of the monomer unit is preferably an electron donating group from the viewpoint of imparting reactivity to the monomer. Specifically, an alkyl group having 1 to 24 carbon atoms, an alkoxy group having 1 to 24 carbon atoms, a halogen group (-F, -Cl, -Br or I) and the like are preferable. Among these, an alkoxy group having 1 to 24 carbon atoms is most preferable from the viewpoint of electron donating properties.

Further, the conductive polymer (A) may contain substituted or unsubstituted aniline, thiophene, It may contain one or more units selected from the group consisting of pyrrole, phenylene, vinylene, divalent unsaturated groups, and divalent saturated groups.

As the conductive polymer (A), a compound having a structure represented by the following general formula (6) is preferable from the viewpoint of expressing high conductivity and solubility. Poly(2-sulfo-5-methoxy-1,4-iminophenylene) is particularly preferred among compounds having a structure represented by the following general formula (6).

In formula (6), each of R ²² to R ³⁷ is independently a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, a linear or branched alkoxy group having 1 to 4 carbon atoms, It represents an acidic group, a hydroxy group, a nitro group, or a halogen atom (-F, -Cl, -Br or I). At least one of R ²² to R ³⁷ is an acidic group or a salt thereof. Also, n indicates the degree of polymerization. In the present invention, n is preferably an integer of 5-2500.

At least part of the acidic groups contained in the conductive polymer (A) is desirably in the free acid form from the viewpoint of improving electrical conductivity.

The weight average molecular weight of the conductive polymer (A) is preferably 1,000 to 1,000,000, more preferably 1,500 to 800,000, more preferably 2,000, in terms of conductivity, solubility, and film-forming properties, in terms of sodium polystyrene sulfonate by GPC. ~500,000 is more preferable, and 2,000 to 100,000 is particularly preferable. If the weight average molecular weight of the conductive polymer (A) is less than 1000, the solubility is excellent, but the conductivity and film formability may be insufficient. On the other hand, when the weight average molecular weight exceeds 1,000,000, the solubility may be insufficient although the conductivity is excellent.
Here, "film formability" refers to the property of forming a uniform film without repelling or the like, and can be evaluated by a method such as spin coating on glass.

A known method can be used as the method for producing the conductive polymer (A), and is not particularly limited as long as the effect of the present invention is achieved.
Specific examples include a method of polymerizing a polymerizable monomer (raw material monomer) having any of the monomer units described above by various synthetic methods such as chemical oxidation and electrolytic oxidation. As such a method, for example, the synthesis methods described in JP-A-7-196791 and JP-A-7-324132 can be applied.

[Conductive composition]
The electrically conductive composition of this embodiment contains the above-described electrically conductive polymer of this embodiment and a solvent (B). The conductive composition may contain a basic compound (C), a surfactant (D) and the like, if necessary.

<Conductive polymer>
The content of the conductive polymer is preferably 0.1 to 5% by mass, more preferably 0.2 to 5% by mass, and further 0.2 to 4% by mass, relative to the total mass of the conductive composition. preferable.
In addition, the content of the conductive polymer is preferably 50 to 100% by mass, more preferably 80 to 100% by mass, and even more preferably 95 to 100% by mass, relative to the total mass of the solid content of the conductive composition. . The solid content of the conductive composition is the residue after removing the solvent (B) from the conductive composition.
If the content of the conductive polymer is within the above range, the coatability of the conductive composition and the conductivity of the coating film formed from the conductive composition are well balanced.

<Solvent (B)>
As the solvent (B), any solvent capable of dissolving the conductive polymer and optionally blended components (basic compound (C), surfactant (D), etc. described later) may be used in the present invention. Water, organic solvents, and mixed solvents of water and organic solvents can be used, although they are not particularly limited as long as they have the effect of (1).
Examples of water include tap water, ion-exchanged water, pure water, ultrapure water, and distilled water.
Examples of organic solvents include alcohols such as methanol, ethanol, isopropyl alcohol, propyl alcohol and butanol; ketones such as acetone and ethyl isobutyl ketone; ethylene glycols such as ethylene glycol and ethylene glycol methyl ether; propylene glycols such as glycol methyl ether, propylene glycol ethyl ether, propylene glycol butyl ether and propylene glycol propyl ether; amides such as dimethylformamide and dimethylacetamide; and pyrrolidones such as N-methylpyrrolidone and N-ethylpyrrolidone. . Any one of these organic solvents may be used alone, or two or more of them may be used by mixing them in an arbitrary ratio.
When a mixed solvent of water and an organic solvent is used as the solvent (B), their mass ratio (water/organic solvent) is preferably 1/100 to 100/1, preferably 2/100 to 100/2. It is more preferable to have

The content of the solvent (B) is preferably 1 to 99.9% by mass, more preferably 10 to 98% by mass, even more preferably 50 to 98% by mass, relative to the total mass of the conductive composition. If the content of the solvent (B) is within the above range, the coatability is further improved.
In addition, the conductive polymer (A) is purified and dissolved in an aqueous medium (hereinafter, the conductive polymer (A) in this state is also referred to as a "conductive polymer solution"). An aqueous medium derived from a solution is also included in the content of the solvent (B) in the conductive composition.

<Basic compound (C)>
Although the basic compound (C) is not essential in the present embodiment, when the conductive polymer is a conductive polymer (A) having an acidic group, the basic compound (C) is added to the conductive polymer The stability of (A) is further improved.

The basic compound (C) is not particularly limited as long as it is a compound having basicity. For example, the following quaternary ammonium salt (c-1), basic compound (c-2), basic compound (c -3).
Quaternary ammonium salt (c-1): A quaternary ammonium compound in which at least one of the four substituents bonded to the nitrogen atom is a hydrocarbon group having 1 or more carbon atoms.
Basic compound (c-2): Basic compound having one or more nitrogen atoms (excluding quaternary ammonium salt (c-1) and basic compound (c-3)).
Basic compound (c-3): A basic compound having a basic group and two or more hydroxy groups in the same molecule and having a melting point of 30°C or higher.

In the quaternary ammonium compound (c-1), the nitrogen atom to which the four substituents are bonded is the nitrogen atom of the quaternary ammonium ion.
In the quaternary ammonium compound (c-1), examples of the hydrocarbon group bonded to the nitrogen atom of the quaternary ammonium ion include an alkyl group, an aralkyl group, and an aryl group.
Examples of the quaternary ammonium compound (c-1) include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetrapentylammonium hydroxide, tetrahexylammonium hydroxide, and benzyltrimethylammonium hydroxide.

Basic compounds (c-2) include, for example, ammonia, pyridine, picoline, triethylamine, 4-dimethylaminopyridine, 4-dimethylaminomethylpyridine, 3,4-bis(dimethylamino)pyridine, 1,5-diazabicyclo [4.3.0]-5-nonene (DBN), 1,8-diazabicyclo[5.4.0]-7-undecene (DBU), and derivatives thereof.

In the basic compound (c-3), basic groups include, for example, basic groups defined as Arrhenius bases, Bronsted bases, Lewis bases and the like. Specifically, ammonia etc. are mentioned. A hydroxy group may be in the state of —OH or in the state of being protected by a protecting group. Examples of protective groups include acetyl group; silyl groups such as trimethylsilyl group and t-butyldimethylsilyl group; acetal type protective groups such as methoxymethyl group, ethoxymethyl group and methoxyethoxymethyl group; benzoyl group; mentioned.
Basic compounds (c-3) include 2-amino-1,3-propanediol, tris(hydroxymethyl)aminomethane, 2-amino-2-methyl-1,3-propanediol, 2-amino-2 -ethyl-1,3-propanediol, 3-[N-tris(hydroxymethyl)methylamino]-2-hydroxypropanesulfonic acid, N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid and the like. .

Any one of these basic compounds may be used alone, or two or more thereof may be mixed and used at any ratio.
Among these, at least one selected from the group consisting of a quaternary ammonium salt (c-1) and a basic compound (c-2) from the viewpoint of easily forming a salt with an acidic group of the conductive polymer (A) is preferably included.

When the basic compound (C) is used, the amount used is based on 1 mol of units having an acidic group among the units constituting the conductive polymer (A), from the viewpoint of further improving the coating properties of the conductive composition. , preferably 0.1 to 1 mol equivalent, more preferably 0.1 to 0.9 mol equivalent. Furthermore, from the viewpoint of excellent retention of performance as a conductive film and more stable acidic groups in the conductive polymer (A), 0.25 to 0.85 mol equivalent is particularly preferred.

<Surfactant (D)>
The conductive composition may contain a surfactant (D).
If the conductive composition contains the surfactant (D), the coatability of the conductive composition is improved when the conductive composition is applied to the substrate or the surface of the resist layer.
Examples of surfactants include anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants. Any one of these surfactants may be used alone, or two or more of them may be used as a mixture in an arbitrary ratio.

Examples of anionic surfactants include sodium dialkylsulfosuccinate, sodium octanoate, sodium decanoate, sodium laurate, sodium myristate, sodium palmitate, sodium stearate, perfluorononanoic acid, sodium N-lauroylsarcosinate, Sodium cocoyl glutamate, alpha sulfo fatty acid methyl ester salt, sodium lauryl sulfate, sodium myristyl sulfate, sodium laureth sulfate, sodium polyoxyethylene alkylphenol sulfonate, ammonium lauryl sulfate, lauryl phosphate, sodium lauryl phosphate, potassium lauryl phosphate, etc. be done.

Examples of cationic surfactants include tetramethylammonium chloride, tetramethylammonium hydroxide, tetrabutylammonium chloride, dodecyldimethylbenzylammonium chloride, alkyltrimethylammonium chloride, octyltrimethylammonium chloride, decyltrimethylammonium chloride, and dodecyl chloride. Trimethylammonium, Tetradecyltrimethylammonium chloride, Cetyltrimethylammonium chloride, Stearyltrimethylammonium chloride, Alkyltrimethylammonium bromide, Hexadecyltrimethylammonium bromide, Benzyltrimethylammonium chloride, Benzyltriethylammonium chloride, Benzalkonium chloride, Benzyl bromide Ruconium, benzethonium chloride, dialkyldimethylammonium chloride, didecyldimethylammonium chloride, distearyldimethylammonium chloride, monomethylamine hydrochloride, dimethylamine hydrochloride, trimethylamine hydrochloride, butylpyridinium chloride, dodecylpyridinium chloride, cetylpyridinium chloride, etc. mentioned.

Examples of amphoteric surfactants include betaine lauryldimethylaminoacetate, betaine stearyldimethylaminoacetate, dodecylaminomethyldimethylsulfopropylbetaine, octadecylaminomethyldimethylsulfopropylbetaine, cocamidopropylbetaine, cocamidopropylhydroxysultaine, 2 -alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, sodium lauroyl glutamate, potassium lauroyl glutamate, lauroylmethyl-β-alanine, lauryldimethylamine-N-oxide, oleyldimethylamine N-oxide and the like. .

Examples of nonionic surfactants include glyceryl laurate, glyceryl monostearate, sorbitan fatty acid ester, sucrose fatty acid ester, polyoxyethylene alkyl ether, pentaethylene glycol monododecyl ether, octaethylene glycol monododecyl ether, poly Oxyethylene alkylphenyl ether, octylphenol ethoxylate, nonylphenol ethoxylate, polyoxyethylene polyoxypropylene glycol, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene hexitane fatty acid ester, sorbitan fatty acid ester polyethylene glycol, lauric acid diethanolamide, oleic acid Diethanolamide, stearic acid diethanolamide, octyl glucoside, decyl glucoside, lauryl glucoside, cetanol, stearyl alcohol, oleyl alcohol and the like.

As the nonionic surfactant, in addition to those mentioned above, a water-soluble polymer having a nitrogen-containing functional group and a terminal hydrophobic group may be used. Unlike conventional surfactants, this water-soluble polymer has a main chain portion (hydrophilic portion) with a nitrogen-containing functional group and a hydrophobic group portion at the end, and has surface activity, improving the coating properties. is high. Therefore, excellent applicability can be imparted to the conductive composition without using other surfactants in combination.

From the viewpoint of solubility, the nitrogen-containing functional group is preferably an amide group.
Examples of terminal hydrophobic groups include alkyl groups, aralkyl groups, aryl groups, alkoxy groups, aralkyloxy groups, aryloxy groups, alkylthio groups, aralkylthio groups, arylthio groups, primary or secondary alkylamino groups, and aralkylamino groups. , an arylamino group, and the like. Among these, an alkylthio group, an aralkylthio group, and an arylthio group are preferred.
The number of carbon atoms in the terminal hydrophobic group is preferably 3-100, more preferably 5-50, and particularly preferably 7-30.
The number of terminal hydrophobic groups in the water-soluble polymer is not particularly limited. Moreover, when two or more terminal hydrophobic groups are present in the same molecule, the terminal hydrophobic groups may be of the same type or of different types.

The water-soluble polymer is mainly a homopolymer of a vinyl monomer having a nitrogen-containing functional group, or a copolymer of a vinyl monomer having a nitrogen-containing functional group and a vinyl monomer having no nitrogen-containing functional group (other vinyl monomer). A compound having a chain structure and having a hydrophobic group at a site other than the repeating unit constituting the polymer is preferred.
Examples of the vinyl monomer having a nitrogen-containing functional group include acrylamide and derivatives thereof, heterocyclic monomers having a nitrogen-containing functional group, etc. Among them, those having an amide bond are preferred. Specifically, acrylamide, N,N-dimethylacrylamide, N-isopropylacrylamide, N,N-diethylacrylamide, N,N-dimethylaminopropylacrylamide, t-butylacrylamide, diacetoneacrylamide, N,N'-methylene bisacrylamide, N-vinyl-N-methylacrylamide, N-vinylpyrrolidone, N-vinylcaprolactam and the like. Among these, acrylamide, N-vinylpyrrolidone, N-vinylcaprolactam and the like are particularly preferable from the viewpoint of solubility.
Other vinyl monomers are not particularly limited as long as vinyl monomers having nitrogen-containing functional groups can be copolymerized, and examples thereof include styrene, acrylic acid, vinyl acetate, and long-chain α-olefins.

Although the method for introducing the terminal hydrophobic group into the water-soluble polymer is not particularly limited, it is usually preferable to introduce it by selecting a chain transfer agent during vinyl polymerization because of its simplicity. In this case, as a chain transfer agent, a group containing a hydrophobic group such as an alkyl group, an aralkyl group, an aryl group, an alkylthio group, an aralkylthio group, an arylthio group, etc. is introduced at the end of the resulting polymer. There are no particular restrictions. For example, when obtaining a water-soluble polymer having an alkylthio group, an aralkylthio group, or an arylthio group as a terminal hydrophobic group, a chain transfer agent having a hydrophobic group corresponding to these terminal hydrophobic groups, specifically a thiol , disulfide, thioether and the like are preferably used for vinyl polymerization.

The main chain portion of the water-soluble polymer is water-soluble and has nitrogen-containing functional groups. The number of units (degree of polymerization) of the main chain portion is preferably 2 to 1000, more preferably 2 to 1000, and particularly preferably 2 to 10 per molecule. If the number of units of the main chain portion having a nitrogen-containing functional group is too large, the surface activity tends to decrease.
Molecular weight ratio (mass average of the main chain portion The molecular weight/mass average molecular weight of the terminal hydrophobic group portion) is preferably 0.3-170.

As the surfactant (D), nonionic surfactants are preferable among the above-mentioned surfactants because they have less influence on the resist layer.

The content of the surfactant (D) is preferably 5 to 80 parts by mass, preferably 10 to 80 parts by mass, when the total of the conductive polymer, the basic compound (C) and the surfactant (D) is 100 parts by mass. 70 parts by mass is more preferable, and 10 to 60 parts by mass is even more preferable. If the content of the surfactant (D) is within the above range, the applicability of the conductive composition to the resist layer is further improved.

<Optional component>
The conductive composition may contain components (optional components) other than the conductive polymer, solvent (B), basic compound (C) and surfactant (D), if necessary.
Examples of optional components include polymer compounds (excluding conductive polymers, basic compounds (C) and surfactants (D)), additives and the like.

Examples of polymer compounds include polyvinyl alcohol derivatives such as polyvinyl formal and polyvinyl butyral; polyacrylamides such as polyacrylamide, poly(Nt-butylacrylamide) and polyacrylamidemethylpropanesulfonic acid; Acrylic acids, water-soluble alkyd resins, water-soluble melamine resins, water-soluble urea resins, water-soluble phenol resins, water-soluble epoxy resins, water-soluble polybutadiene resins, water-soluble acrylic resins, water-soluble urethane resins, water-soluble acrylic styrene copolymers Resins, water-soluble vinyl acetate acrylic copolymer resins, water-soluble polyester resins, water-soluble styrene-maleic acid copolymer resins, water-soluble fluorine resins, and copolymers thereof.
Examples of additives include pigments, antifoaming agents, ultraviolet absorbers, antioxidants, heat resistance improvers, leveling agents, anti-sagging agents, matting agents and preservatives.

<Method for producing conductive composition>
The conductive composition is produced by mixing the conductive polymer of the present embodiment, the solvent (B), and, if necessary, the basic compound (C), the surfactant (D) and optional components.
For example, when using a solid conductive polymer (A), the solid conductive polymer (A) and the solvent (B) are mixed in advance to prepare a conductive polymer solution, and the resulting conductive polymer solution A conductive composition can be obtained by adding a basic compound (C) or the like as necessary.
When using a conductive polymer solution such as the conductive polymer (A) after ion exchange treatment, a basic compound (C) or the like is added to the conductive polymer solution as necessary to obtain a conductive composition. be able to. Moreover, the conductive polymer solution may be further diluted with the solvent (B) as necessary.

<Application>
The conductive composition of the present embodiment is suitable for antistatic use during charged particle beam drawing. Specifically, the conductive film formed by coating the conductive composition of the present embodiment on the surface of the resist layer serves as an antistatic film of the resist layer.
In addition, the conductive composition of the present embodiment can also be used as materials for capacitors, transparent electrodes, semiconductors, and the like.

<Method for Forming Conductive Film>
The method for forming a conductive film of the present embodiment includes a step of forming a coating film by applying a conductive composition on the surface to be treated (coating step), and the coating without heating the coating film to 50 ° C. or higher. It has a drying step of removing the solvent in the film to form a conductive film.

(Coating process)
The coating step is a step of applying a conductive composition containing a conductive polymer and a solvent onto the surface to be treated to form an undried coating film.
The surface to be treated is the surface to which the conductive composition is applied. For example, when forming a conductive film on various substrates, the surface of the substrate is the surface to be treated. When the conductive film is formed on the surface of the resist layer of the substrate having the resist layer on one side, the surface of the resist layer is the surface to be processed.

The substrate is not particularly limited as long as it has the effect of the present invention, but polyester resins such as PET and PBT, polyethylene, polyolefin resins typified by polypropylene, vinyl chloride, nylon, polystyrene, polycarbonate, epoxy resin, fluororesin, Polysulfone, polyimide, polyurethane, phenolic resin, silicone resin, synthetic paper, and other polymer compound moldings, films, paper, iron, glass, quartz glass, various wafers (substrates), aluminum, copper, zinc, nickel, Examples include stainless steel and the like, and those coated with various paints, photosensitive resins, resists, and the like on the surface of these base materials.
The shape of the substrate is not particularly limited, and may be a plate shape or a shape other than the plate shape.
The step of applying the conductive composition to the surface to be treated may be performed before or during the manufacturing process of these substrates, such as uniaxial stretching, biaxial stretching, molding, or embossing. Often, these treatment steps can also be performed on substrates that have been completed.

The conductive composition is applied onto the substrate so that the thickness of the coating film after drying is 30 nm or less, preferably 5 to 30 nm.
The method of applying the conductive composition to the substrate is not particularly limited as long as the effect of the present invention is achieved, and may be spin coating, spray coating, dip coating, roll coating, gravure coating, or reverse coating. , a roll brush method, an air knife coating method, a curtain coating method, and the like.

(Drying process)
A drying process is a process of removing the solvent in a coating film. It is preferable to dry sufficiently so that the amount of solvent in the coating film after the drying process is as small as possible.
In the drying step of this embodiment, the solvent in the coating film is removed without heating the coating film to 50° C. or higher. For example, the following method (1) or method (2) can be used.
Method (1): A method in which the coating film is heated to less than 50°C in a reduced pressure atmosphere to remove the solvent in the coating film.
Method (2): A method of removing the solvent in the coating film by holding the coating film in a dry gas atmosphere for 10 minutes or longer.

In the method (1), the pressure of the reduced pressure atmosphere is preferably 0.1 Pa or less, more preferably 10 ⁻³ Pa or less. When the viscosity is 0.1 Pa or less, the coating film is easily dried sufficiently.
In method (1), the coating is heated to facilitate evaporation of the solvent in the coating. For example, it is preferable to heat the coating film so that the surface temperature of the coating film is equal to or higher than the boiling point of the solvent in the coating film under atmospheric pressure and lower than 50°C. When it is at least the lower limit of the above range, it is easy to efficiently and sufficiently dry the coating film. When the temperature is less than 50°C, the components in the coating film are less likely to be denatured by heat.
In the method (1), the drying time is defined as the time during which the coating film is present in the reduced pressure atmosphere. The drying time is preferably set to a time during which the solvent in the coating film is sufficiently removed. For example, 1 minute or more is preferable, and 2 minutes or more is more preferable. From the viewpoint of production efficiency, the upper limit is preferably 200 minutes or less, more preferably 150 minutes or less.
In the method (1), air, inert gas, etc. can be exemplified as the ambient gas. Air is preferred from the point of view of equipment.

In the above method (2), as the dry gas, a gas that has undergone water removal treatment by a known method can be used. Examples of gas types include air, nitrogen gas, argon gas, and the like.
In method (2), the dry gas atmosphere is preferably normal temperature and normal pressure from the viewpoint of equipment. Heating, pressure reduction, etc. may be performed as necessary.
In method (2), a flowing dry gas may be brought into contact with the coating to facilitate evaporation of the solvent in the coating.
In method (2), the drying time is defined as the time during which the coating film is in contact with the drying gas. The drying time is 10 minutes or more, and it is preferable to set the time to sufficiently remove the solvent in the coating film. It is preferably 15 minutes or more.

According to the method for forming a conductive film of the present embodiment, since the coating film is not exposed to heat of 50 ° C. or higher in the drying process, while suppressing thermal denaturation of the components in the coating film, volatile components such as solvents in the coating film can be removed.
For example, when the coating film contains the conductive polymer (A), thermal denaturation such as detachment of acidic groups due to heating is suppressed. Moreover, when the coating film contains an additive, thermal denaturation such as melting of the additive due to heating is suppressed. Therefore, the transfer of such thermally denatured substances to the lower layer of the conductive film is suppressed, and the influence on the lower layer is suppressed.
In addition, since volatile components such as solvents in the conductive film are removed, contamination inside the exposure apparatus can be suppressed.

<Method for manufacturing conductor>
The method for producing a conductor of the present embodiment is a method in which the surface of a base material is used as a surface to be treated, and a conductive film is formed on the surface to be treated by the method of forming a conductive film of the present embodiment to produce a conductor. be.
The conductor of this embodiment has a base material and a conductive film provided on the base material. A conductive film is provided on at least part of the surface of the substrate.
The base material is the same as the base material in the method for forming a conductive film described above.

According to the method for manufacturing a conductor of the present embodiment, since the conductive film is not exposed to heat of 50° C. or more in the process of forming the conductive film, heat denaturation in the conductive film is unlikely to occur, and heat denaturation due to thermally denatured substances is unlikely to occur. The influence on the base material is suppressed.

<Method of forming resist pattern>
The method of forming a resist pattern of the present embodiment is performed by using the method of forming a conductive film of the present embodiment on a substrate having a resist layer on one side thereof, with the surface of the resist layer being the surface to be processed. and an exposure step of patternwise irradiating the resist layer with a charged particle beam from the conductive film side.
Further, after the exposure step, a washing step of removing the conductive film by washing with water, a developing step of developing the resist layer to form a resist pattern, and the like are performed as necessary.
When the resist layer is made of a chemically amplified resist, it is preferable to perform a post-exposure bake (hereinafter also referred to as PEB) step of heating after the exposure step and before the development step.

(Lamination process)
In the lamination step, a conductive film is formed on the surface of the resist layer of the substrate having the resist layer on one side thereof.
The substrate is not particularly limited as long as it has the effect of the present invention, but glass, quartz glass, various wafers, aluminum, copper, zinc, nickel, tantalum, stainless steel, etc., and various paints and photosensitive resins on the surface of these substrates. are coated.

A resist layer of positive or negative type resist is provided on one side of the substrate.
The positive resist is not particularly limited as long as it has sensitivity to charged particle beams, and known ones can be used. A chemically amplified resist containing an acid generator that generates an acid upon irradiation with a charged particle beam and a polymer containing a structural unit having an acid-decomposable group is preferred.
A positive resist layer can be formed by a known method. For example, a positive resist layer can be formed by applying an organic solvent solution of a resist onto one side of the substrate and, if necessary, heating (pre-baking) it.

The negative type resist is not particularly limited as long as it has sensitivity to charged particle beams, and known ones can be used. A chemically amplified resist containing an acid generator that generates an acid upon irradiation with a charged particle beam, a developer-soluble polymer, and a cross-linking agent is preferred.
The negative resist layer can be formed by a known method, similarly to the positive resist layer.

Using the surface of the resist layer as a surface to be processed, a conductive film is formed by the above-described method for forming a conductive film according to the present embodiment. As a result, a laminate in which the substrate, the resist layer, and the conductive film are laminated in this order is obtained. The film thickness of the conductive film is 30 nm or less, preferably 5 to 30 nm.

(Exposure process)
The exposure step is a step of patternwise irradiating the resist layer with a charged particle beam. Specifically, the laminate is irradiated with a charged particle beam from the conductive film side.
The exposure step forms a latent image in the resist layer between the substrate and the conductive film. When the resist layer is made of a chemically amplified resist, acid is generated from the acid generator in the charged particle beam irradiation area (exposed area).
At this time, since the conductive film is provided on the surface of the resist layer, the conductive film can be grounded, and the entire laminate can be prevented from being charged. Therefore, it is possible to suppress the positional deviation of electrons incident on the resist layer due to the effects of charging, and to form a latent image corresponding to the desired resist pattern with high accuracy.

(PEB process)
The PEB step is a step of heating (PEB) the resist layer after the exposure step. For example, the laminate is heated by a known heating means such as a hot plate.
When the resist layer irradiated with a charged particle beam in the exposure process is heated, in the case of a positive resist layer, the reaction is accelerated by the action of the acid generated from the acid generator in the charged particle beam irradiated area (exposed area). and increased solubility in the developer. On the other hand, in the case of a negative resist layer, the solubility in the developer decreases.
The heating conditions vary depending on the resist, but are preferably 200° C. or less and within 1 hour from the viewpoint of the heat resistance of the conductive film.

(Washing and developing process)
The washing/developing step is a step of removing the conductive film by washing with water and developing the resist layer to form a resist pattern.
Since the conductive film is water-soluble, the conductive film is dissolved and removed by washing with water.
Water washing indicates contacting with an aqueous liquid. Examples of the aqueous liquid include simple water, water containing at least one of a base and a basic salt, water containing an acid, a mixture of water and a water-soluble organic solvent, and the like.

When the positive resist layer is developed, the charged particle beam irradiated portion (exposed portion) of the positive resist layer is dissolved and removed, resulting in a resist pattern consisting of the charged particle beam unirradiated portion (unexposed portion) of the positive resist layer. is formed.
On the other hand, when the negative resist layer is developed, the charged particle beam non-irradiated portion (non-exposed portion) is dissolved and removed, contrary to the case of the positive resist layer, and the charged particle beam irradiated portion of the negative resist layer is removed. A resist pattern consisting of (exposed portions) is formed.

The washing/development step can be performed, for example, by the following method (α) or (β).
Method (α): Using an alkaline developer for washing, the conductive film is removed and the resist layer is developed.
Method (β): Only the conductive film is removed by washing with water, and then the resist layer is developed with a developer.

The alkaline developer (aqueous alkaline solution) used in the method (α) is not particularly limited, and known ones can be used. For example, tetramethylammonium hydroxide aqueous solution and the like can be mentioned.
The water washing of the method (β) can be carried out using an aqueous solution that does not correspond to a developer, such as water. Development can be carried out using an alkaline developer as in method (α).

Further, after the water washing/developing process, the substrate may be rinsed with pure water or the like, if necessary.
After the water washing/development step or after the rinse treatment, the substrate having the resist pattern formed thereon may be heated (post-baked), if necessary.

According to the method of forming a resist pattern of the present embodiment, since volatile components such as solvents in the coating film are removed in the drying process, contamination inside the exposure apparatus can be suppressed. In addition, since the conductive film is not exposed to heat of 50° C. or more in the process of forming the conductive film on the resist layer, heat denaturation in the conductive film is unlikely to occur, and the resist layer is not affected by thermally denatured substances. suppressed. For example, in a mode in which a conductive film containing a conductive polymer (A) is formed on the surface of a resist layer made of a chemically amplified resist, film reduction of the resist layer can be improved.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the following examples are not intended to limit the scope of the present invention.
Measurement methods and evaluation methods in Examples and Comparative Examples are as follows.

[Measurement method/evaluation method]
<Conductive evaluation method>
2.0 mL of the conductive composition is dropped onto the glass substrate, and a coating film is formed by spin coating under the conditions of 2000 rpm × 60 seconds with a spin coater so as to cover the entire substrate surface. Drying was performed by a drying method to form a conductive film having a film thickness of about 30 nm on the substrate to obtain a conductor.
Using Hiresta UX-MCP-HT800 (manufactured by Mitsubishi Chemical Analytech Co., Ltd.), the surface resistance value [Ω/□] of the conductive film was measured by a two-terminal method (distance between electrodes: 20 mm).

<Evaluation by Film Reduction Test>
(Measurement of film reduction amount)
A chemically amplified electron beam resist (hereinafter abbreviated as “resist”) was used, and the film reduction amount of the resist layer was measured by the following procedures (1A) to (8A). In this method, the PEB step (4A) was omitted in order to confirm the influence of the drying step during the formation of the conductive film.
(1A) Formation of resist layer: 0.2 μL of resist was spin-coated on a 4-inch silicon wafer as a base material with a spin coater under conditions of 2000 rpm×60 seconds, and then pre-baked at 130° C. for 90 seconds on a hot plate. , the solvent was removed, and a resist layer was formed on the substrate.
(2A) Thickness measurement of resist layer 1: Part of the resist layer formed on the substrate is peeled off, and the substrate surface is used as a reference position, and a stylus profiler (Stylus profiler P-16+, KLA-Tencor Corporation) was used to measure the initial film thickness a [nm] of the resist layer.
(3A) Formation of conductive film: 2 mL of a conductive composition is dropped onto the resist layer, and the entire surface of the resist layer is coated by spin coating at 1000 rpm for 100 seconds using a spin coater to form a coating film. After that, a drying process was performed under the drying conditions of each example to remove the solvent in the coating film, and a conductive film having a thickness of about 60 nm was formed on the resist layer.
(5A) Washing with water: After washing the conductive film with 20 mL of water, it was spun at 2000 rpm for 60 seconds with a spin coater to remove water on the surface of the resist layer.
(6A) Development: 20 mL of a developer consisting of a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution was dropped onto the surface of the resist layer. After standing still for 60 seconds, the resist layer was rotated at 2000 rpm for 60 seconds with a spin coater to remove the developer on the surface of the resist layer, and then dried by maintaining rotation for 60 seconds.
(7A) Thickness measurement of resist layer 2: After stripping part of the resist layer within 5 mm from the part where the resist layer was partially stripped in (2A), the resist after development using a stylus type step meter The film thickness b [nm] of the layer was measured.
(8A) Calculation of film thickness reduction amount: The film thickness reduction amount c [nm] (c=ab) of the resist layer was calculated by subtracting the film thickness b value from the film thickness a value.

(Measurement of reference film reduction amount)
The amount of film reduction was measured without forming a conductive film on the resist layer. That is, the film reduction amount not caused by the conductive film (hereinafter referred to as “reference film reduction amount”) d [nm] was measured by the following procedures (1B) to (6B). The PEB step (3B) was omitted.
(1B) Formation of resist layer: A resist layer was formed on the substrate in the same manner as in (1A) above.
(2B) Film thickness measurement 1 of resist layer: The initial film thickness a [nm] of the resist layer was measured in the same manner as in (2A) above.
(4B) Development: Development was carried out in the same manner as in (6A) above.
(5B) Thickness measurement of resist layer 2: After stripping a part of the resist layer within 5 mm from the part where the resist layer was stripped in (2B), the resist layer after development was measured using a stylus profilometer. A film thickness e [nm] was measured.
(6B) Calculation of amount of film thickness reduction: Subtracting the value of film thickness e from the value of film thickness a, the reference film thickness reduction amount d (d=ae) of the resist layer was calculated.
The reference film thickness reduction amount d of the resist layer was 3 nm.

(Calculation of film reduction amount of resist layer caused by conductive film)
Subtract the value of the reference film reduction amount d of the resist layer from the value of the film reduction amount c of the resist layer to calculate the film reduction amount f [nm] (f = cd) of the resist layer due to the conductive film. and evaluated according to the following evaluation criteria. The smaller the amount of film loss f, the better, and A and B are accepted.
A: The film reduction amount f is less than 10 nm.
B: The film reduction amount f is 10 nm or more and less than 20 nm.
C: The film reduction amount f is 20 nm or more.

<Production of conductive polymer (A)>
[Production Example 1]
100 mmol of pyridine and 100 mL of water were added to 100 mmol of 2-aminoanisole-4-sulfonic acid to obtain a monomer solution.
An aqueous solution (oxidant solution) of 100 mmol of ammonium peroxodisulfate was added dropwise at 10° C. to the resulting monomer solution. After completion of dropping, the mixture was further stirred at 25°C for 15 hours, then heated to 35°C and further stirred for 2 hours to obtain a reaction liquid in which a reaction product precipitated (polymerization step).
The obtained reaction solution is filtered with a centrifugal filter, the precipitate (reaction product) is recovered, the reaction product is washed with 1 L of methanol and then dried to obtain a powdery conductive polymer (A1). obtained (purification step).

<Production of conductive composition>
[Production Example 2]
A conductive composition (1) was obtained by mixing 1 part by mass of the conductive polymer (A1) with 95 parts by mass of water and 4 parts by mass of isopropyl alcohol (IPA) as the solvent (B).

[Example 1, Example 2, Comparative Example 1]
By the method shown in the procedure (1A) of the film reduction test, a substrate having a resist layer made of a chemically amplified resist on one side is manufactured, and the surface of the resist layer is used as the surface to be processed, and the following is applied on the surface to be processed. A conductive film was formed by the method.
The conductivity of the obtained conductive film was evaluated by the method described above, and a film reduction test was performed. Table 1 shows the results.

In Example 1, the conductive composition (1) was applied on the surface to be treated by the method shown in the film reduction test procedure (3A) to form a coating film, and a vacuum dryer (internal pressure 10 to 5 Pa ) and dried for 10 minutes while heating so that the surface temperature of the coating film was maintained at 30±3° C. to form a conductive film.

In Example 2, a coating film was formed in the same manner as in Example 1, and dried by holding for 30 minutes in a dryer filled with dry nitrogen gas (25° C.) to form a conductive film.

In Comparative Example 1, a coating film was formed in the same manner as in Example 1, and was dried for 10 minutes while heating with a hot plate so that the surface temperature of the coating film was maintained at 120 ± 5 ° C. to form a conductive film. formed.

As shown in the results of Table 1, in Examples 1 and 2, the solvent in the coating film was removed without heating the coating film to 50°C or higher, so that the resist layer, which is the lower layer of the conductive film, was reduced. was suppressed.
On the other hand, in Comparative Example 1 in which the coating film was heated to 120° C. in the drying process, the amount of film reduction of the resist layer was greater than in Examples 1 and 2. In Comparative Example 1, when the coating film was heated in the drying step, the acidic group was detached from the conductive polymer (A) to generate an acid component, and the acid component migrated to the resist layer. It is presumed that the solubility of the resist layer in the developing solution increased, resulting in film thinning.

According to the present invention, it is possible to form a conductive film that has little effect on the underlying layer. For example, an antistatic film can be formed on the resist layer, which has little effect on the resist layer.

Claims (7)

A method for forming a conductive film formed on the surface of a resist layer, comprising:
A step of applying a conductive composition containing a conductive polymer and a solvent on the surface to be processed of the resist layer to form a coating film, and the coating film without heating the coating film to 50 ° C. or higher. Having a drying step of removing the solvent inside to form a conductive film,
A method of forming a conductive film, wherein in the drying step, the conductive film is formed in a reduced pressure atmosphere or in a dry gas atmosphere . 2. The method of forming a conductive film according to claim 1, wherein in said drying step, said coating film is heated in a reduced pressure atmosphere to a boiling point of a solvent in said coating film or higher and lower than 50[deg.] C. at atmospheric pressure. 2. The method of forming a conductive film according to claim 1, wherein said coating film is held in a dry gas atmosphere for 10 minutes or longer in said drying step. The method for forming a conductive film according to any one of claims 1 to 3, wherein the conductive polymer contains a conductive polymer having an acidic group. A method for producing a conductor having a substrate and a conductive film provided on the substrate, wherein the surface of the substrate is the surface to be treated, and the method according to any one of claims 1 to 4 A method for producing a conductor, comprising forming a conductive film by the method described. A lamination step of forming a conductive film by the method according to any one of claims 1 to 4, using the surface of the resist layer of a substrate having a resist layer on one side as the surface to be processed, and On the other hand, a method of forming a resist pattern, comprising an exposure step of patternwise irradiating a charged particle beam from the conductive film side. 7. The method of forming a resist pattern according to claim 6, wherein said resist layer is made of a chemically amplified resist.