JP2009188318A - Pattern forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly practically usable pattern forming method with which more refined patterns can be easily and efficiently formed, and which can be applied to semiconductor manufacturing processes, and a radio-sensible resin composition used therefor. <P>SOLUTION: A pattern forming method includes: (1) a step of forming a negative type latent image pattern by exposing a resist layer 2 constituted of a radio-sensible resin composition, that becomes alkali-soluble under an exposure amount A and becomes alkali-insoluble or refractory under an exposure amount B (wherein exposure amount A < exposure amount B), under the exposure amount B via a first mask including a first opening pattern; (2) a step of forming a positive type latent image pattern 14 by exposing the resist layer 2 under the exposure amount A via a second mask 22 including a second opening pattern; and (3) a step of developing the resist layer under alkali conditions. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for forming a fine pattern.

  In the field of microfabrication represented by the manufacture of integrated circuit elements, in order to obtain a higher degree of integration, recently, lithography technology capable of microfabrication at a level of 0.1 μm or less is required. However, in the conventional lithography process, near-ultraviolet rays such as i-rays are generally used as radiation, and it is said that fine processing at a subquarter micron level is extremely difficult with this near-ultraviolet rays. Therefore, in order to enable microfabrication at a level of 0.1 μm or less, use of radiation having a shorter wavelength is being studied. Examples of such short-wavelength radiation include an emission line spectrum of a mercury lamp, far-ultraviolet rays typified by an excimer laser, an X-ray, an electron beam, and the like. Among these, a KrF excimer laser (wavelength 248 nm) is particularly preferable. ) Or ArF excimer laser (wavelength 193 nm) has been attracting attention.

  As a resist suitable for irradiation with such an excimer laser, a component having an acid dissociable functional group and a component that generates an acid upon irradiation with radiation (hereinafter also referred to as “exposure”) (hereinafter referred to as “acid generator”) Many resists using the chemical amplification effect (hereinafter also referred to as “chemically amplified resist”) have been proposed. As the chemically amplified resist, for example, a resist containing a resin having a tert-butyl ester group of carboxylic acid or a tert-butyl carbonate group of phenol and an acid generator has been proposed (see, for example, Patent Document 1). ). In this resist, the tert-butyl ester group or tert-butyl carbonate group present in the resin is dissociated by the action of an acid generated by exposure, and the resin has an acidic group composed of a carboxyl group or a phenolic hydroxyl group. As a result, the phenomenon that the exposed region of the resist film becomes readily soluble in an alkali developer is utilized.

  In such a lithography process, further fine pattern formation (for example, a fine resist pattern having a line width of about 45 nm) will be required in the future. In order to achieve such fine pattern formation of less than 45 nm, it is conceivable to shorten the light source wavelength of the exposure apparatus and increase the numerical aperture (NA) of the lens as described above. However, a new expensive exposure apparatus is required to shorten the light source wavelength. Further, when the lens has a high NA, the resolution and the depth of focus are in a trade-off relationship. Therefore, there is a problem that the depth of focus decreases even if the resolution is increased.

  Recently, as a lithography technique capable of solving such a problem, a method called an immersion exposure (liquid immersion lithography) method has been reported (for example, see Patent Document 2). In this method, at the time of exposure, a liquid high refractive index medium (immersion exposure liquid) such as pure water or a fluorine-based inert liquid having a predetermined thickness on at least the resist film between the lens and the resist film on the substrate. Is to intervene. In this method, a light source having the same exposure wavelength can be used by replacing the exposure optical path space, which has conventionally been an inert gas such as air or nitrogen, with a liquid having a higher refractive index (n), such as pure water. Similar to the case of using a light source with a shorter wavelength or the case of using a high NA lens, high resolution is achieved and there is no reduction in the depth of focus. If such immersion exposure is used, it is possible to realize the formation of a resist pattern that is low in cost, excellent in high resolution, and excellent in depth of focus, using a lens mounted on an existing apparatus. It has attracted a great deal of attention and is being put to practical use.

  However, it is said that the extension of the above-described exposure technique is limited to 45 nmhp, and technical development for the 32 nmhp generation that requires further fine processing is being carried out. In addition, since an apparatus (immersion exposure apparatus) used for immersion exposure is extremely expensive, there is a fact that it is not practical in an actual semiconductor manufacturing process.

  On the other hand, there is a pattern forming method in which thin films formed on the left and right wall surfaces of a dummy pattern are used as a gate electrode after the dummy pattern is removed in order to reduce LWR (Linewidth Roughness) in accordance with the demand for more complex and higher density devices. It has been proposed (see Non-Patent Document 1, for example). In the pattern forming method proposed in Non-Patent Document 1, variation in threshold voltage of transistors is evaluated to reduce LWR. However, there is a situation that it is difficult to use for forming a finer pattern.

Japanese Patent Laid-Open No. 5-232704 JP-A-10-303114 International Electron Devices Meeting Technical Digest, pp. 863-866, Dec. 2005

  The present invention has been made in view of such problems of the prior art, and the problem is that a finer pattern can be easily and efficiently formed and the semiconductor manufacturing process can be performed. An object of the present invention is to provide a highly practical pattern forming method that can be applied.

  As a result of intensive studies to achieve the above-described problems, the present inventors have found that the above-described problems can be achieved by adopting the following configuration, and have completed the present invention.

  That is, according to the present invention, the following pattern forming method is provided.

  [1] It was formed on a substrate made of a radiation-sensitive resin composition that became alkali-soluble at exposure amount A and became insoluble or hardly soluble at exposure amount B (however, exposure amount A <exposure amount B). (1) a negative latent image pattern forming step of forming a negative latent image pattern by exposing the resist layer with an exposure amount B through a first mask having a first opening pattern; and (2) A positive latent image pattern forming step of forming a positive latent image pattern by exposing with an exposure amount A through a second mask having a second opening pattern different from the first opening pattern; (3) A developing step of developing in an alkaline condition to form a third pattern having a first pattern derived from the negative latent image pattern and a second pattern derived from the positive latent image pattern And a pattern forming method comprising:

  [2] The pattern forming method according to [1], wherein the positive latent image pattern forming step is performed after the negative latent image pattern forming step.

  [3] The pattern forming method according to [2], wherein a portion of the resist layer that has not been exposed in the negative latent image pattern forming step is exposed in the positive latent image pattern forming step.

  [4] The pattern forming method according to [1], wherein the negative latent image pattern forming step is performed after the positive latent image pattern forming step.

  [5] The pattern forming method according to [4], wherein a portion of the resist layer exposed in the positive latent image pattern forming step is further exposed in the negative latent image pattern forming step.

  According to the pattern forming method of the present invention, a finer resist pattern can be easily and efficiently formed. For this reason, the pattern forming method of the present invention is highly practical and can be applied to a semiconductor manufacturing process.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described below, but the present invention is not limited to the following embodiment, and is based on the ordinary knowledge of those skilled in the art without departing from the gist of the present invention. It should be understood that modifications and improvements as appropriate to the following embodiments also fall within the scope of the present invention.

1. Radiation sensitive resin composition:
The radiation-sensitive resin composition (hereinafter also simply referred to as “resist agent”) used in the pattern forming method of the present invention becomes alkali-soluble at an exposure amount A and becomes insoluble or hardly soluble at an exposure amount B (however, exposure Amount A <exposure amount B). In other words, the resist agent used in the pattern forming method of the present invention has a characteristic that it becomes alkali-soluble at a lower exposure amount and becomes insoluble or hardly soluble at a higher exposure amount, with a predetermined exposure amount region as a boundary. It is.

  Specific examples of the resist agent having the above-described characteristics include a crosslinking agent (A), a resin (B) containing an acid labile group, a radiation-sensitive acid generator (C), and an acid diffusion inhibitor (D). And a solvent (E) composition, or a copolymer (F) of a resin (B) containing a crosslinking agent (A) and an acid labile group, a radiation sensitive acid generator (C), an acid diffusion inhibitor ( The composition containing D) and a solvent (E) can be mentioned as a suitable example. The resist agent used in the pattern forming method of the present invention exhibits both positive and negative responsiveness depending on the exposure level. That is, on the low exposure amount side, the increase in the solubility of the composition due to the action of the acid exceeds the decrease in the solubility due to the action of the crosslinking agent. On the other hand, on the high exposure amount side, since the decrease in solubility due to the action of the crosslinking agent exceeds the increase in solubility of the composition due to the action of acid, it exhibits negative responsiveness. FIG. 12 is a graph showing the relationship between the exposure amount and the resist layer thickness of the resist agent used in the pattern forming method of the present invention.

(Crosslinking agent (A))
The cross-linking agent (A) acts as a cross-linking component (curing component) that causes at least the resin (B) to react with the action of an acid to be cross-linked (cured). Specific examples of the crosslinking agent (A) include a compound containing a group represented by the following general formula (1) (hereinafter also referred to as “crosslinking agent I”), and a compound containing two or more cyclic ethers as a reactive group. (Hereinafter also referred to as “crosslinking agent II”), or a compound containing two or more vinyl groups as reactive groups (hereinafter also referred to as “crosslinking agent III”), or “crosslinking agent I” or “crosslinking agent II”. , And a mixture of two or more of “Crosslinking agent III”.

In the general formula (1), R ¹ and R ² represent a hydrogen atom or a group represented by the following general formula (2). However, at least one of R ¹ and R ² is a group represented by the following general formula (2).

In the general formula (2), R ³ and R ⁴ are a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxyalkyl group having 1 to 6 carbon atoms, or a carbon number in which R ³ and R ⁴ are bonded to each other. R 2 represents a ring having 2 to 10 and R ⁵ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

  Specific examples of the compound containing the group represented by the general formula (1) (crosslinking agent I) include (poly) methylolated melamine, (poly) methylolated glycoluril, (poly) methylolated benzoguanamine, (poly) Examples thereof include nitrogen-containing compounds obtained by alkyl etherifying part or all of active methylol groups such as methylolated urea. Here, examples of the alkyl group that alkylates the active methylol group include at least one of a methyl group, an ethyl group, and a butyl group. The nitrogen-containing compound may contain an oligomer component that is partially self-condensed. Specific examples of the nitrogen-containing compound include hexamethoxymethylated melamine, hexabutoxymethylated melamine, tetramethoxymethylated glycoluril, tetrabutoxymethylated glycoluril and the like.

  Specific examples of commercially available nitrogen-containing compounds include Cymel 300, 301, 303, 350, 232, 235, 236, 238, 266, 267, 285, 1123, 1123-10, 1170, 370, 771, 772, 172, 1172, 325, 327, 703, 712, 254, 253, 212, 1128, 701, 202, 207 (Nippon Cytec Co., Ltd.), Nikarac MW-30M, 30, 30, 22, 24X, Niracak MS-21, 11, 001, Niracak MX-002, 730, 750, 708, 708, 706, 042, 035, 45, 410, 302, 202, Niracac SM-651, 652, 653, 551, 451, Nilaca SB-401, 355, 303, 301, 255, 203, 201, Niracak BX-4000, 37, 55H, Niracak BL-60 (manufactured by Sanwa Chemical Co., Ltd.), etc. be able to.

Among them, as the crosslinking agent I, either R ¹ or R ^{2 in} the general formula (1) is a hydrogen atom (that is, contains an imino group), Cymel 325, 327, 703, 703, 712, 254, 253, 212, 1128, 701, 202, and 207 are preferable.

  Specific examples of the crosslinking agent II include 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy). Cyclohexane-meta-dioxane, bis (3,4-epoxycyclohexylmethyl) adipate, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6-methylcyclohexyl-3 ′, 4 ′ -Epoxy-6'-methylcyclohexanecarboxylate, methylene bis (3,4-epoxycyclohexane), di (3,4-epoxycyclohexylmethyl) ether of ethylene glycol, ethylene bis (3,4-epoxycyclohexanecarboxylate), epsilon -Caprolactone modified 3 4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, trimethylcaprolactone modified 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, β-methyl-δ-valerolactone modified 3, Epoxycyclohexyl group-containing compounds such as 4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate; bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, Brominated bisphenol F diglycidyl ether, brominated bisphenol S diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol di Polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol and glycerin; glycidyl ethers, polypropylene glycol diglycidyl ethers; Diglycidyl esters of basic acids; monoglycidyl ethers of higher aliphatic alcohols; phenol, cresol, butylphenol, or these Monoglycidyl ethers of polyether alcohols obtained by adding ruxylene oxide; glycidyl esters of higher fatty acids; 3,7-bis (3-oxetanyl) -5-oxa-nonane, 3,3 ′-(1, 3- (2-methylenyl) propanediylbis (oxymethylene)) bis- (3-ethyloxetane), 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, 1,3-benzenedicarboxylic Acid bis [(3-ethyl-3-oxetanyl) methyl] ester, 1,2-bis [(3-ethyl-3-oxetanylmethoxy) methyl] ethane, 1,3-bis [(3-ethyl-3-oxetanyl) Methoxy) methyl] propane, ethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, dicyclopenteni Bis (3-ethyl-3-oxetanylmethyl) ether, triethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, tetraethyleneglycol bis (3-ethyl-3-oxetanylmethyl) ether, tricyclodecanediyldi Methylene (3-ethyl-3-oxetanylmethyl) ether, trimethylolpropane tris (3-ethyl-3-oxetanylmethyl) ether, 1,4-bis (3-ethyl-3-oxetanylmethoxy) butane, 1,6- Bis (3-ethyl-3-oxetanylmethoxy) hexane, pentaerythritol tris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, polyethylene glycol bis (3- Til-3-oxetanylmethyl) ether, dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol pentakis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol tetrakis (3- Ethyl-3-oxetanylmethyl) ether, caprolactone-modified dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether, caprolactone-modified dipentaerythritol pentakis (3-ethyl-3-oxetanylmethyl) ether, ditrimethylolpropane Tetrakis (3-ethyl-3-oxetanylmethyl) ether, ethylene oxide (EO) modified bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, propylene ether Xoxide (PO) modified bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, EO modified hydrogenated bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, PO modified hydrogenated bisphenol A bis (3-ethyl Examples thereof include oxetane compounds having two or more oxetane rings in the molecule, such as -3-oxetanylmethyl) ether and EO-modified bisphenol F (3-ethyl-3-oxetanylmethyl) ether.

  Among them, as the crosslinking component II, 1,3-benzenedicarboxylic acid, bis [(3-ethyl-3-oxetanyl) methyl] ester, 1,6-hexanediol diglycidyl ether, dipentaerythritol hexakis (3- Ethyl-3-oxetanylmethyl) ether is preferred.

  Specific examples of the crosslinking component III include 1,3,5-triacryloylhexahydro-1,3,5-triazine, triallylamine, triallyl1,3,5-benzenetricarboxylate, 2,4,6-triaryloxy -1,3,5-triazine, 1,3,5-triallyl-1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione, 1,3,5-tris (2 -Methyl-2-propenyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione and the like.

  Of these, 1,3,5-triallyl-1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione is preferable as the crosslinking component III.

  The compounding quantity of a crosslinking agent (A) is 1-60 mass parts normally with respect to 100 mass parts of resin (B), Preferably it is 2-50 mass parts. If the amount is less than 1 part by mass, inactivation to light becomes insufficient, and the formed pattern may be deteriorated. On the other hand, if it exceeds 60 parts by mass, the pattern tends to be difficult to resolve.

(Resin containing acid labile group (B))
Resin (B) (hereinafter also referred to as “resist agent resin”) is a component in which an acid dissociable group is dissociated by the action of an acid generated from an acid generator by exposure to increase the solubility in an alkali developer. . The resin (B) preferably has a repeating unit represented by the following general formula (3).

In the general formula (3), R ⁶ represents a hydrogen atom or a methyl group, and R ⁷ independently of each other, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or carbon The linear or branched alkyl group of Formula 1-4 is shown. Further, at least one of (i) a plurality of R ^7, or a monovalent alicyclic hydrocarbon group or a derivative thereof having 4 to 20 carbon atoms, or (ii) 2 both R ⁷ are bonded to each other, A divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms including a carbon atom to which each is bonded or a derivative thereof is formed, and the remaining R ⁷ is linear or branched having 1 to 4 carbon atoms Or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof.

In the general formula (3), a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms represented by R ⁷ and 2 to ⁷ carbon atoms formed by bonding two R ⁷ to each other. Specific examples of the divalent alicyclic hydrocarbon group include fats derived from cycloalkanes such as norbornane, tricyclodecane, tetracyclododecane, adamantane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, and cyclooctane. A group consisting of a cyclic ring; a group consisting of these alicyclic rings is, for example, a methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methyl Examples include a group substituted with one or more of linear, branched, and cyclic alkyl groups having 1 to 4 carbon atoms such as a propyl group and a t-butyl group. Of these, a group consisting of an alicyclic ring derived from norbornane, tricyclodecane, tetracyclododecane, adamantane, cyclopentane, or cyclohexane, or a group obtained by substituting these with the above alkyl group is preferable.

In the general formula (3), specific examples of the derivative of the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms represented by R ⁷ include a hydroxyl group; a carboxyl group; an oxo group (that is, ═O Group); hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 1-hydroxypropyl group, 2-hydroxypropyl group, 3-hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3 A hydroxyalkyl group having 1 to 4 carbon atoms such as -hydroxybutyl group and 4-hydroxybutyl group; methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, 2-methylpropoxy group, 1 -C1-C4 alkoxyl group such as methylpropoxy group and t-butoxy group; cyano group; cyanomethyl group, 2-cyanoethyl group, 3-cyanopropyl group And a group having 2 to 5 carbon atoms having one or more substituents such as a cyanoalkyl group such as a propyl group and a 4-cyanobutyl group. Of these, a hydroxyl group, a carboxyl group, a hydroxymethyl group, a cyano group, and a cyanomethyl group are preferable.

In the general formula (3), specific examples of the linear or branched alkyl group having 1 to 4 carbon atoms represented by R ⁷ include a methyl group, an ethyl group, an n-propyl group, i- A propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group and the like can be mentioned. Of these, a methyl group and an ethyl group are preferable.

In the general formula (3), specific examples of the group represented by “—C (R ⁷ ) ₃ ” include groups represented by the following (general) formulas (3a) to (3f). .

In the general formulas (3a) to (3c), (3e), and (3f), R ⁷ independently represents a linear or branched alkyl group having 1 to 4 carbon atoms. In the general formula (3c), m represents 0 or 1. Specific examples of the linear or branched alkyl group having 1 to 4 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1- Examples thereof include a methylpropyl group and a t-butyl group. Of these, a methyl group and an ethyl group are preferable.

  Specific examples of the repeating unit other than the repeating unit having an acid dissociable group represented by the (general) formulas (3a) to (3f) (hereinafter also referred to as “other repeating units”) include the following general formula ( The repeating unit which has a lactone structure represented by 3-1)-(3-8) can be mentioned.

In the general formulas (3-1) to (3-8), R ⁶ represents a hydrogen atom or a methyl group. In addition, resin (B) may contain 2 or more types of these repeating units.

In the general formula (3), the moiety represented by “—COOC (R ⁷ ) ₃ ” is a moiety that is dissociated by the action of an acid to form a carboxyl group to form an alkali-soluble site. This “alkali-soluble site” is a group that becomes an anion (alkali-soluble) by the action of an alkali. On the other hand, an “acid-dissociable group” is a group in which an alkali-soluble site is protected with a protecting group, and is a group that is not “alkali-soluble” until the protecting group is removed with an acid.

  The resist agent resin itself is a resin that is insoluble in alkali or hardly soluble in alkali, but is resin that becomes alkali-soluble by the action of an acid. Here, “alkali insoluble or alkali poorly soluble” is a developing condition for forming a pattern using a resist layer comprising a resist agent containing a resin having a repeating unit represented by the general formula (3). When a film made only of a resin containing the repeating unit represented by the general formula (3) is processed (but not exposed), 50% or more of the initial film thickness remains after the processing. Say. On the other hand, “alkali-soluble” refers to a property in which 50% or more of the initial film thickness of the film is lost after the same treatment.

  The polystyrene-reduced weight average molecular weight Mw measured by gel permeation chromatography (GPC) of the resist agent resin is usually 1,000 to 500,000, preferably 1,000 to 100,000, and more preferably 1,000. ~ 50,000. If Mw is less than 1,000, the heat resistance of the pattern to be formed tends to decrease. On the other hand, if the Mw exceeds 500,000, the developability tends to be lowered. Moreover, it is preferable that ratio (Mw / Mn) of Mw of resin for resist agents and the polystyrene conversion number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is 1-5, More preferably. In addition, it is preferable that the ratio of the low molecular weight component which has a monomer as a main component contained in resin for resist agents is 0.1 mass% or less in conversion of solid content with respect to the whole resin. The content ratio of the low molecular weight component can be measured, for example, by high performance liquid chromatography (HPLC).

(Method for producing resin for resist agent)
Resist agent resin is a radical polymerization of a monomer component containing a polymerizable unsaturated monomer corresponding to a desired repeating unit, such as hydroperoxides, dialkyl peroxides, diacyl peroxides, and azo compounds. It can manufacture by using an initiator and superposing | polymerizing in a suitable solvent in presence of a chain transfer agent as needed.

  Examples of the solvent used for polymerization include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane; cyclohexane, cycloheptane, cyclooctane, decalin, norbornane. Cycloalkanes such as benzene, toluene, xylene, ethylbenzene, cumene and other aromatic hydrocarbons; chlorobutanes, bromohexanes, dichloroethanes, halogenated hydrocarbons such as hexamethylene dibromide, chlorobenzene; ethyl acetate, Saturated carboxylic acid esters such as n-butyl acetate, i-butyl acetate and methyl propionate; ethers such as tetrahydrofuran, dimethoxyethanes and diethoxyethane; methanol, ethanol, 1-propanol, 2-propanol, 1- Butanol, 2-pig Alcohol, isobutanol, 1-pentanol, 3-pentanol, 4-methyl-2-pentanol, o-chlorophenol, 2- (1-methylpropyl) phenol, etc .; acetone, 2-butanone, Mention may be made of ketones such as 3-methyl-2-butanone, 4-methyl-2-pentanone, 2-heptanone, cyclopentanone, cyclohexanone and methylcyclohexanone. These solvents can be used alone or in combination of two or more.

  Moreover, the reaction temperature in said superposition | polymerization is 40-150 degreeC normally, Preferably it is 50-120 degreeC, and reaction time is 1-48 hours normally, Preferably it is 1-24 hours. In addition, the resin for a resist agent to be obtained is preferable as the content of impurities such as halogen and metal is smaller because sensitivity, resolution, process stability, pattern profile and the like can be further improved. Examples of resist resin purification methods include chemical purification methods such as water washing and liquid-liquid extraction, and combinations of these chemical purification methods and physical purification methods such as ultrafiltration and centrifugation, etc. Can be mentioned.

(Copolymer (F))
A copolymer (F) is a component obtained by copolymerizing the above-mentioned crosslinking agent (A) and resin for resist agents (resin (B)). The radiation-sensitive resin composition can contain this copolymer (F) instead of the crosslinking agent (A) and the resist agent resin. Specific examples of the crosslinking agent (A) used for obtaining the copolymer (F) include those having a repeating unit (crosslinking group) represented by the following general formulas (4) and (5). it can. That is, as a specific example of the copolymer (F), a crosslinking group represented by at least one of the following general formula (4) and the following general formula (5) is introduced into the resist resin. Can be mentioned.

In the general formula (4), R ⁸ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, A represents a methylene, ethylene, or propylene group, and R ⁹ represents the following formula (6) or ( The group represented by 7) is shown. In the general formula (5), R ⁸ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, R ¹⁰ represents a methylene group or an alkylene group having 2 to 6 carbon atoms, and R ¹¹ represents a hydrogen atom. , Methyl group, or ethyl group, and n = 0 or 1.

(Radiation sensitive acid generator (C))
The acid generator (C) has a property of being decomposed by exposure. The acid generator (C) preferably has a structure represented by the following general formula (8).

In the general formula (8), R ¹⁴ is a hydrogen atom, a fluorine atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, or a linear or branched group having 1 to 10 carbon atoms. Or a linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms. R ¹² represents a linear or branched alkyl group or alkoxyl group having 1 to 10 carbon atoms, or a linear, branched or cyclic alkanesulfonyl group having 1 to 10 carbon atoms.

In the general formula (8), R ¹³ is independently a linear or branched alkyl group having 1 to 10 carbon atoms, an optionally substituted phenyl group, or a substituted group. Or two R ¹³ may be bonded to each other to form a divalent group having 2 to 10 carbon atoms. In addition, the formed bivalent group may be substituted. k is an integer of 0 to 2, and X ⁻ is a general formula: RC _n F _2n SO ₃ ⁻ (wherein R is a fluorine atom or an optionally substituted hydrocarbon group having 1 to 12 carbon atoms. N is an integer of 1 to 10), and q is an integer of 0 to 10.

In the general formula (8), examples of the linear or branched alkyl group having 1 to 10 carbon atoms represented by R ¹² , R ¹³ , and R ¹⁴ include a methyl group, an ethyl group, and n-propyl. Group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, n-pentyl group, neopentyl group, n-hexyl group, n-heptyl group, n-octyl Group, 2-ethylhexyl group, n-nonyl group, n-decyl group and the like. Of these, a methyl group, an ethyl group, an n-butyl group, a t-butyl group, and the like are preferable.

In the general formula (8), examples of the linear or branched alkoxyl group having 1 to 10 carbon atoms represented by R ¹² and R ¹³ include a methoxy group, an ethoxy group, an n-propoxy group, i- Propoxy group, n-butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group, n-pentyloxy group, neopentyloxy group, n-hexyloxy group, n-heptyloxy group, n- An octyloxy group, 2-ethylhexyloxy group, n-nonyloxy group, n-decyloxy group, etc. can be mentioned. Of these, a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group and the like are preferable.

In the general formula (8), examples of the linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms represented by R ¹⁴ include a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, i -Propoxycarbonyl group, n-butoxycarbonyl group, 2-methylpropoxycarbonyl group, 1-methylpropoxycarbonyl group, t-butoxycarbonyl group, n-pentyloxycarbonyl group, neopentyloxycarbonyl group, n-hexyloxycarbonyl group N-heptyloxycarbonyl group, n-octyloxycarbonyl group, 2-ethylhexyloxycarbonyl group, n-nonyloxycarbonyl group, n-decyloxycarbonyl group and the like. Of these, a methoxycarbonyl group, an ethoxycarbonyl group, an n-butoxycarbonyl group, and the like are preferable.

In the general formula (8), examples of the linear, branched, or cyclic alkanesulfonyl group having 1 to 10 carbon atoms represented by R ¹⁴ include a methanesulfonyl group, an ethanesulfonyl group, and n-propanesulfonyl. Group, n-butanesulfonyl group, tert-butanesulfonyl group, n-pentanesulfonyl group, neopentanesulfonyl group, n-hexanesulfonyl group, n-heptanesulfonyl group, n-octanesulfonyl group, 2-ethylhexanesulfonyl group n -Nonanesulfonyl group, n-decanesulfonyl group, cyclopentanesulfonyl group, cyclohexanesulfonyl group, etc. can be mentioned. Of these, a methanesulfonyl group, an ethanesulfonyl group, an n-propanesulfonyl group, an n-butanesulfonyl group, a cyclopentanesulfonyl group, a cyclohexanesulfonyl group, and the like are preferable. Moreover, q is preferably 0-2.

In the general formula (8), examples of the optionally substituted phenyl group represented by R ¹³ include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, and 2,3-dimethylphenyl. Group, 2,4-dimethylphenyl group, 2,5-dimethylphenyl group, 2,6-dimethylphenyl group, 3,4-dimethylphenyl group, 3,5-dimethylphenyl group, 2,4,6-trimethylphenyl Group, 4-ethylphenyl group, 4-t-butylphenyl group, 4-cyclohexylphenyl group, 4-fluorophenyl group and the like; linear, branched or cyclic alkyl having 1 to 10 carbon atoms A phenyl group substituted by a group; these phenyl group or alkyl-substituted phenyl group can be converted into a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxy group; Examples include a group substituted with at least one group such as an alkyl group, an alkoxycarbonyl group, and an alkoxycarbonyloxy group. Examples of the alkoxyl group among the substituents for the phenyl group and the alkyl-substituted phenyl group include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, a 2-methylpropoxy group, 1 Examples thereof include linear, branched, or cyclic alkoxyl groups having 1 to 20 carbon atoms such as a methylpropoxy group, a t-butoxy group, a cyclopentyloxy group, and a cyclohexyloxy group.

  Examples of the alkoxyalkyl group include 2 to 21 carbon atoms such as a methoxymethyl group, an ethoxymethyl group, a 1-methoxyethyl group, a 2-methoxyethyl group, a 1-ethoxyethyl group, and a 2-ethoxyethyl group. And a linear, branched, or cyclic alkoxyalkyl group. Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, an i-propoxycarbonyl group, an n-butoxycarbonyl group, a 2-methylpropoxycarbonyl group, and a 1-methylpropoxycarbonyl group. , T-butoxycarbonyl group, cyclopentyloxycarbonyl group, cyclohexyloxycarbonyl, etc., having 2 to 21 carbon atoms, such as linear, branched, or cyclic alkoxycarbonyl groups.

Examples of the alkoxycarbonyloxy group include methoxycarbonyloxy group, ethoxycarbonyloxy group, n-propoxycarbonyloxy group, i-propoxycarbonyloxy group, n-butoxycarbonyloxy group, t-butoxycarbonyloxy group, Examples thereof include linear, branched, or cyclic alkoxycarbonyloxy groups having 2 to 21 carbon atoms such as cyclopentyloxycarbonyl group and cyclohexyloxycarbonyl. In the general formula (8), the optionally substituted phenyl group represented by R ¹³ includes a phenyl group, a 4-cyclohexylphenyl group, a 4-t-butylphenyl group, a 4-methoxyphenyl group, a 4-t -A butoxyphenyl group and the like are preferable.

In the general formula (8), examples of the optionally substituted naphthyl group represented by R ¹³ include 1-naphthyl group, 2-methyl-1-naphthyl group, 3-methyl-1-naphthyl group, 4 -Methyl-1-naphthyl group, 4-methyl-1-naphthyl group, 5-methyl-1-naphthyl group, 6-methyl-1-naphthyl group, 7-methyl-1-naphthyl group, 8-methyl-1- Naphthyl group, 2,3-dimethyl-1-naphthyl group, 2,4-dimethyl-1-naphthyl group, 2,5-dimethyl-1-naphthyl group, 2,6-dimethyl-1-naphthyl group, 2,7 -Dimethyl-1-naphthyl group, 2,8-dimethyl-1-naphthyl group, 3,4-dimethyl-1-naphthyl group, 3,5-dimethyl-1-naphthyl group, 3,6-dimethyl-1-naphthyl Group, 3,7-dimethyl-1-naphthyl group, 3 , 8-dimethyl-1-naphthyl group, 4,5-dimethyl-1-naphthyl group, 5,8-dimethyl-1-naphthyl group, 4-ethyl-1-naphthyl group, 2-naphthyl group, 1-methyl- A naphthyl group such as a 2-naphthyl group, a 3-methyl-2-naphthyl group, and a 4-methyl-2-naphthyl group; substituted with a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms One or more of these naphthyl groups or alkyl-substituted naphthyl groups in at least one group such as a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxyalkyl group, an alkoxycarbonyl group, and an alkoxycarbonyloxy group. Examples include substituted groups. Specific examples of the alkoxyl group, alkoxyalkyl group, alkoxycarbonyl group, and alkoxycarbonyloxy group among these substituents include the groups exemplified for the aforementioned phenyl group and alkyl-substituted phenyl group.

In the general formula (8), the optionally substituted naphthyl group represented by R ¹³ includes 1-naphthyl group, 1- (4-methoxynaphthyl) group, 1- (4-ethoxynaphthyl) group, 1 -(4-n-propoxynaphthyl) group, 1- (4-n-butoxynaphthyl) group, 2- (7-methoxynaphthyl) group, 2- (7-ethoxynaphthyl) group, 2- (7-n- And propoxynaphthyl) group and 2- (7-n-butoxynaphthyl) group.

In the general formula (8), the divalent group having 2 to 10 carbon atoms formed by bonding two R ¹³ to each other together with the sulfur atom in the general formula (8) is a 5-membered or 6-membered ring. Groups that form a ring, preferably a 5-membered ring (ie, a tetrahydrothiophene ring) are desirable. Examples of the substituent for the divalent group include a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxyalkyl group, an alkoxy group exemplified as the substituent for the phenyl group and the alkyl-substituted phenyl group. Examples thereof include a carbonyl group and an alkoxycarbonyloxy group. Incidentally, as the R ¹³ in the general formula (8), a methyl group, an ethyl group, a phenyl group, a 4-methoxyphenyl group, 1-naphthyl group, tetrahydrothiophene two R ¹³ are taken together with the attached to a sulfur atom each other to form a ring structure A divalent group or the like that forms is preferable.

  Examples of the cation moiety in the general formula (8) include triphenylsulfonium cation, tri-1-naphthylsulfonium cation, tri-tert-butylphenylsulfonium cation, 4-fluorophenyl-diphenylsulfonium cation, di-4-fluorophenyl- Phenylsulfonium cation, tri-4-fluorophenylsulfonium cation, 4-cyclohexylphenyl-diphenylsulfonium cation, 4-methanesulfonylphenyl-diphenylsulfonium cation, 4-cyclohexanesulfonyl-diphenylsulfonium cation, 1-naphthyldimethylsulfonium cation, 1- Naphthyldiethylsulfonium cation, 1- (4-hydroxynaphthyl) dimethylsulfonium cation, 1- (4 Methylnaphthyl) dimethylsulfonium cation, 1- (4-methylnaphthyl) diethylsulfonium cation, 1- (4-cyanonaphthyl) dimethylsulfonium cation, 1- (4-cyanonaphthyl) diethylsulfonium cation, 1- (3,5- Dimethyl-4-hydroxyphenyl) tetrahydrothiophenium cation, 1- (4-methoxynaphthyl) tetrahydrothiophenium cation, 1- (4-ethoxynaphthyl) tetrahydrothiophenium cation, 1- (4-n-propoxynaphthyl) ) Tetrahydrothiophenium cation, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium cation, 2- (7-methoxynaphthyl) tetrahydrothiophenium cation, 2- (7-ethoxynaphthyl) tetrahi B thiophenium cation, 2- (7-n- propoxy-naphthyl) tetrahydrothiophenium cation, 2- (7-n- butoxynaphthyl) can be exemplified tetrahydrothiophenium cation, or the like.

In the general formula (8), the “C _n F _2n —” group in the anion represented by X ⁻ (general formula: RC _n F _2n SO ³⁻ ) is a perfluoroalkylene group having n carbon atoms. However, the perfluoroalkylene group may be linear or branched. Note that n is preferably 1, 2, 4, or 8. The optionally substituted hydrocarbon group having 1 to 12 carbon atoms represented by R is preferably an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, or a bridged alicyclic hydrocarbon group. Specifically, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, n-pentyl group, neopentyl group N-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, norbornyl group, norbornylmethyl group, hydroxynorbornyl group, adamantyl group Etc.

  Preferred anion sites in the general formula (8) include trifluoromethanesulfonate anion, perfluoro-n-butanesulfonate anion, perfluoro-n-octanesulfonate anion, 2-bicyclo [2.2.1] hept-2- Yl-1,1,2,2-tetrafluoroethanesulfonate anion, 2-bicyclo [2.2.1] hept-2-yl-1,1-difluoroethanesulfonate anion, and the like.

  Said acid generator (C) can be used individually by 1 type or in combination of 2 or more types. In addition, it is also possible to use "other acid generators" other than said acid generator (C). Specific examples of “other acid generators” include onium salt compounds, halogen-containing compounds, diazoketone compounds, sulfone compounds, and sulfonic acid compounds.

  Examples of the onium salt compounds include iodonium salts, sulfonium salts, phosphonium salts, diazonium salts, pyridinium salts, and the like. Specific examples of the onium salt compound include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1] hepta-2. -Yl-1,1,2,2-tetrafluoroethanesulfonate, bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis ( 4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, bis (4-t-butylphenyl) iodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2- Te La tetrafluoroethane sulfonate, cyclohexyl 2-oxo-cyclohexyl methyl trifluoromethanesulfonate, dicyclohexyl-2-oxo-cyclohexyl trifluoromethane sulfonate, and 2-oxo-cyclohexyl dimethyl sulfonium trifluoromethanesulfonate, and the like.

  Examples of the halogen-containing compound include haloalkyl group-containing hydrocarbon compounds and haloalkyl group-containing heterocyclic compounds. Specific examples of halogen-containing compounds include (trichloromethyl such as phenylbis (trichloromethyl) -s-triazine, 4-methoxyphenylbis (trichloromethyl) -s-triazine, 1-naphthylbis (trichloromethyl) -s-triazine. ) -S-triazine derivatives and 1,1-bis (4-chlorophenyl) -2,2,2-trichloroethane.

  Examples of the diazoketone compound include a 1,3-diketo-2-diazo compound, a diazobenzoquinone compound, a diazonaphthoquinone compound, and the like. Specific examples of the diazo ketone include 1,2-naphthoquinonediazide-4-sulfonyl chloride, 1,2-naphthoquinonediazide-5-sulfonyl chloride, 1,2, naphthoquinonediazide of 2,3,4,4′-tetrahydroxybenzophenone. -4-sulfonic acid ester or 1,2-naphthoquinonediazide-5-sulfonic acid ester; 1,1,1-naphthoquinonediazide-4-sulfonic acid ester of 1,1,1-tris (4-hydroxyphenyl) ethane Examples include 2-naphthoquinonediazide-5-sulfonic acid ester.

  Examples of the sulfone compound include β-ketosulfone, β-sulfonylsulfone, α-diazo compounds of these compounds, and the like. Specific examples of the sulfone compound include 4-trisphenacylsulfone, mesitylphenacylsulfone, bis (phenylsulfonyl) methane, and the like.

  Examples of the sulfonic acid compounds include alkyl sulfonic acid esters, alkyl sulfonic acid imides, haloalkyl sulfonic acid esters, aryl sulfonic acid esters, and imino sulfonates. Specific examples of the sulfonic acid compounds include benzoin tosylate, pyrogallol tris (trifluoromethanesulfonate), nitrobenzyl-9,10-diethoxyanthracene-2-sulfonate, trifluoromethanesulfonylbicyclo [2.2.1] hept- 5-ene-2,3-dicarbodiimide, nonafluoro-n-butanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, perfluoro-n-octanesulfonylbicyclo [2.2 .1] Hept-5-ene-2,3-dicarbodiimide, 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonylbicyclo [2.2. 1] Hept-5-ene-2,3-dicarbodiimide, N- (trifluoromethanesulfonyl Xyl) succinimide, N- (nonafluoro-n-butanesulfonyloxy) succinimide, N- (perfluoro-n-octanesulfonyloxy) succinimide, N- (2-bicyclo [2.2.1] hept-2-yl- 1,1,2,2-tetrafluoroethanesulfonyloxy) succinimide, 1,8-naphthalenedicarboxylic imide trifluoromethanesulfonate, 1,8-naphthalenedicarboxylic imidononafluoro-n-butanesulfonate, 1,8-naphthalenedicarboxylic Examples include acid imido perfluoro-n-octane sulfonate. These “other acid generators” can be used singly or in combination of two or more.

  It is also preferable to use the acid generator (C) having the structure represented by the general formula (8) and “other acid generator” in combination. When “other acid generator” is used in combination, the ratio of “other acid generator” used is the sum of the acid generator having the structure represented by the general formula (8) and “other acid generator”. Is usually 80% by mass or less, preferably 60% by mass or less.

  From the viewpoint of ensuring the sensitivity and developability of the resist agent, the total content of the acid generator contained in the resist agent (the total content of the acid generator (C) and “other acid generator”) is as follows. The amount is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the resin for resist agent. When the total content of the acid generator is less than 0.1 parts by mass, the sensitivity and developability of the resist agent tend to be lowered. On the other hand, if it exceeds 20 parts by mass, the transparency to radiation is lowered, and it tends to be difficult to form a rectangular resist pattern.

(Acid diffusion control agent (D))
The resist agent preferably contains an acid diffusion control agent (D). The acid diffusion control agent (D) is a component having an action of controlling a diffusion phenomenon of an acid generated from an acid generator upon exposure in a resist layer and suppressing an undesirable chemical reaction in a non-exposed region. By blending such an acid diffusion control agent (D), the storage stability of the resist agent is improved, the resolution of the resist is further improved, and the holding time from exposure to heat treatment after exposure (PED) A change in the line width of the resist pattern due to fluctuations in the thickness of the resist pattern can be suppressed, and a composition having excellent process stability can be obtained. As the acid diffusion controller (D), it is preferable to use a nitrogen-containing organic compound or a photodisintegratable base. This photodegradable base is an onium salt compound that is decomposed by exposure and exhibits acid diffusion controllability.

(Nitrogen-containing organic compounds)
Examples of the nitrogen-containing organic compound include a compound represented by the following general formula (9) (hereinafter, also referred to as “nitrogen-containing compound (I)”), a compound having two nitrogen atoms in the same molecule (hereinafter, “ Nitrogen-containing compound (II) ”, polyamino compounds having three or more nitrogen atoms in the same molecule and polymers thereof (hereinafter collectively referred to as“ nitrogen-containing compound (III) ”), amide group-containing compounds , Urea compounds, nitrogen-containing heterocyclic compounds, and the like.

In the general formula (9), R ^{15 s} are independently of each other a hydrogen atom, a substituted or unsubstituted linear, branched or cyclic alkyl group, a substituted or unsubstituted aryl group, or a substituted or non-substituted group. A substituted aralkyl group is shown.

  Examples of the nitrogen-containing compound (I) include mono (cyclo) alkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, cyclohexylamine; di-n- Butylamine, di-n-pentylamine, di-n-hexylamine, di-n-heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine, cyclohexylmethylamine, dicyclohexylamine, etc. Di (cyclo) alkylamines; triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine , Tri-n-nonylamine, tri-n-decylamine, cyclohexyl Tri (cyclo) alkylamines such as dimethylamine, methyldicyclohexylamine and tricyclohexylamine; substituted alkylamines such as 2,2 ′, 2 ″ -nitrotriethanol; aniline, N-methylaniline, N, N-dimethylaniline 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, diphenylamine, triphenylamine, naphthylamine, 2,4,6-tri-tert-butyl-N-methylaniline, N-phenyldiethanolamine Aromatic amines such as 2,6-diisopropylaniline are preferred.

  Examples of the nitrogen-containing compound (II) include ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diaminodiphenylmethane, and 4,4′-diaminodiphenylether. 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylamine, 2,2-bis (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 2, -(4-aminophenyl) -2- (3-hydroxyphenyl) propane, 2- (4-aminophenyl) -2- (4-hydroxyphenyl) propane, 1,4-bis [1- (4-aminophenyl) ) -1-methylethyl] benzene, 1,3-bis [1- (4-aminophenyl) -1-methyl ester Benzene], bis (2-dimethylaminoethyl) ether, bis (2-diethylaminoethyl) ether, 1- (2-hydroxyethyl) -2-imidazolidinone, 2-quinoxalinol, N, N, N ′ , N′-tetrakis (2-hydroxypropyl) ethylenediamine, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine and the like are preferable.

  As the nitrogen-containing compound (III), for example, polyethyleneimine, polyallylamine, 2-dimethylaminoethylacrylamide polymer and the like are preferable.

  Examples of the amide group-containing compound include Nt-butoxycarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-n-decylamine, Nt- Butoxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-2-adamantylamine, Nt-butoxycarbonyl-N-methyl-1-adamantylamine, (S)-( -)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, (R)-(+)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, Nt-butoxycarbonyl-4-hydroxypiperidine Nt-butoxycarbonylpyrrolidine, Nt-butoxycarbonyl Perazine, N, N-di-t-butoxycarbonyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-N-methyl-1-adamantylamine, Nt-butoxycarbonyl-4,4′- Diaminodiphenylmethane, N, N′-di-t-butoxycarbonylhexamethylenediamine, N, N, N′N′-tetra-t-butoxycarbonylhexamethylenediamine, N, N′-di-t-butoxycarbonyl-1 , 7-diaminoheptane, N, N′-di-t-butoxycarbonyl-1,8-diaminooctane, N, N′-di-t-butoxycarbonyl-1,9-diaminononane, N, N′-di- t-butoxycarbonyl-1,10-diaminodecane, N, N′-di-t-butoxycarbonyl-1,12-diaminododecane, N, N -Di-t-butoxycarbonyl-4,4'-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, Nt-butoxycarbonyl-2-phenylbenzimidazole Nt-butoxycarbonyl group-containing amino compounds such as Nt-butoxycarbonylpyrrolidine, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide Propionamide, benzamide, pyrrolidone, N-methylpyrrolidone, N-acetyl-1-adamantylamine, isocyanuric acid tris (2-hydroxyethyl) and the like are preferable.

  Examples of urea compounds include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tri-n-butylthiourea. Etc. are preferred. Examples of the nitrogen-containing heterocyclic compound include imidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2- Imidazoles such as methyl-1H-imidazole; pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4-phenylpyridine , Nicotine, nicotinic acid, nicotinamide, quinoline, 4-hydroxyquinoline, 8-oxyquinoline, acridine, pyridines such as 2,2 ′: 6 ′, 2 ″ -terpyridine; piperazine, 1- (2-hydroxyethyl ) In addition to piperazines such as piperazine, Gin, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, piperidine ethanol, 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1- (4-morpholinyl) ethanol, 4-acetylmorpholine, 3 -(N-morpholino) -1,2-propanediol, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane and the like are preferable.

(Photodegradable base)
A photodegradable base is an onium salt compound that generates a base that decomposes upon exposure and exhibits acid diffusion controllability. Specific examples of such an onium salt compound include a sulfonium salt compound represented by the following general formula (10) and an iodonium salt compound represented by the following general formula (11).

In the general formulas (10) and (11), R ^{16 to} R ²⁰ each independently represent a hydrogen atom, an alkyl group, an alkoxyl group, a hydroxyl group, or a halogen atom. Z ⁻ represents OH ⁻ , R—COO ⁻ , R—SO ₃ ^— (wherein R represents an alkyl group, an aryl group, or an alkaryl group), or an anion represented by the following formula (12). Show.

  Specific examples of the sulfonium salt compound and the iodonium salt compound include triphenylsulfonium hydroxide, triphenylsulfonium acetate, triphenylsulfonium salicylate, diphenyl-4-hydroxyphenylsulfonium hydroxide, diphenyl-4-hydroxyphenylsulfonium acetate, Diphenyl-4-hydroxyphenylsulfonium salicylate, bis (4-t-butylphenyl) iodonium hydroxide, bis (4-t-butylphenyl) iodonium acetate, bis (4-t-butylphenyl) iodonium hydroxide, bis (4-t-butylphenyl) iodonium acetate, bis (4-t-butylphenyl) iodonium salicylate, 4-t-butyl Enyl-4-hydroxyphenyliodonium hydroxide, 4-t-butylphenyl-4-hydroxyphenyliodonium acetate, 4-t-butylphenyl-4-hydroxyphenyliodonium salicylate, bis (4-t-butylphenyl) iodonium Examples thereof include 10-camphor sulfonate, diphenyliodonium 10-camphor sulfonate, triphenylsulfonium 10-camphor sulfonate, and 4-t-butoxyphenyl diphenylsulfonium 10-camphor sulfonate.

  The above acid diffusion controller (D) can be used alone or in combination of two or more. The compounding amount of the acid diffusion controller (D) is usually 15 parts by mass or less, preferably 10 parts by mass or less, and more preferably 5 parts by mass or less with respect to 100 parts by mass of the resist resin. When the blending amount of the acid diffusion controller (D) is more than 15 parts by mass, the sensitivity of the resist agent tends to decrease. If the amount of the acid diffusion controller (D) is less than 0.001 part by mass, the shape and dimensional fidelity of the resist pattern may be lowered depending on the process conditions.

(Solvent (E))
The resist agent is preferably obtained by dissolving a resin for a resist agent, an acid generator (C), an acid diffusion controller (D) and the like in a solvent (E). The solvent (E) is preferably at least one selected from the group consisting of propylene glycol monomethyl ether acetate, 2-heptanone, and cyclohexanone (hereinafter also referred to as “solvent (1)”). In addition, a solvent other than the solvent (1) (hereinafter, also referred to as “other solvent”) can be used. Furthermore, the solvent (1) and other solvents can be used in combination.

  Examples of other solvents include propylene glycol monoethyl ether acetate, propylene glycol mono-n-propyl ether acetate, propylene glycol mono-i-propyl ether acetate, propylene glycol mono-n-butyl ether acetate, propylene glycol mono-i- Propylene glycol monoalkyl ether acetates such as butyl ether acetate, propylene glycol mono-sec-butyl ether acetate, propylene glycol mono-t-butyl ether acetate; 2-butanone, 2-pentanone, 3-methyl-2-butanone, 2-hexanone, Linear or 4-methyl-2-pentanone, 3-methyl-2-pentanone, 3,3-dimethyl-2-butanone, 2-octanone, etc. Branched ketones;

  Cyclic ketones such as cyclopentanone, 3-methylcyclopentanone, 2-methylcyclohexanone, 2,6-dimethylcyclohexanone, isophorone; methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, 2-hydroxypropionic acid n-propyl, i-propyl 2-hydroxypropionate, n-butyl 2-hydroxypropionate, i-butyl 2-hydroxypropionate, sec-butyl 2-hydroxypropionate, t-butyl 2-hydroxypropionate, etc. Alkyl 2-hydroxypropionates; in addition to alkyl 3-alkoxypropionates such as methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate,

  n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclohexanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether , Diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol di-n-propyl ether, diethylene glycol di-n-butyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-propyl ether acetate, propylene glycol monomethyl ether , Propylene glycol monoethyl Ether, propylene glycol mono-n-propyl ether, toluene, xylene, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutyrate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, 3-methyl-3-methoxybutyl butyrate, ethyl acetate, n-propyl acetate, n-butyl acetate, methyl acetoacetate, Ethyl acetoacetate, methyl pyruvate, ethyl pyruvate, N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, benzyl ethyl ether, di-n-hexyl ether, diethylene glycol monomethyl ether, diethylene glycol Cole monoethyl ether, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, etc. Can do.

  Of these solvents, linear or branched ketones, cyclic ketones, propylene glycol monoalkyl ether acetates, alkyl 2-hydroxypropionate, alkyl 3-alkoxypropionate, γ-butyrolactone and the like are preferable. . These solvents can be used singly or in combination of two or more.

  When the solvent (1) and another solvent are used in combination as the solvent (E), the proportion of the other solvent is usually 50% by mass or less, preferably 30% by mass or less, more preferably 25%, based on the total solvent. It is below mass%. The amount of the solvent (E) contained in the resist agent is such that the concentration of the total solid contained in the resist agent is usually 2 to 70% by mass, preferably 4 to 25% by mass, and more preferably 4 to 10%. It is the amount that becomes mass%.

  The resist agent is prepared by dissolving each component in the solvent (E) so that the total solid content concentration is in the above-described numerical range to obtain a uniform solution, and then filtering with a filter having a pore size of about 0.02 μm, for example. Can be prepared.

  Various additives such as a surfactant, a sensitizer, and an aliphatic additive can be blended with the resist agent as necessary.

  A surfactant is a component that exhibits an effect of improving coating properties, striation, developability, and the like. Examples of such surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, and polyethylene glycol dilaurate. Nonionic surfactants such as polyethylene glycol distearate; hereinafter referred to as KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (above, manufactured by Kyoeisha Chemical Co., Ltd.), F-top EF301, EF303, EF352 (above, manufactured by Tochem Products), Megafax F171, F173 (above, manufactured by Dainippon Ink and Chemicals), Florard FC430, FC431 (above, manufactured by Sumitomo 3M), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 ( As mentioned above, Asahi Glass Co., Ltd.) can be mentioned. These surfactants can be used singly or in combination of two or more. The compounding quantity of surfactant is 2 mass parts or less normally with respect to 100 mass parts of resin (B).

  The sensitizer absorbs radiation energy and transmits the energy to the acid generator, thereby increasing the amount of acid generated, and has the effect of improving the apparent sensitivity of the resist agent. Have. Examples of such sensitizers include carbazoles, acetophenones, benzophenones, naphthalenes, phenols, biacetyl, eosin, rose bengal, pyrenes, anthracenes, phenothiazines, and the like. These sensitizers can be used individually by 1 type or in combination of 2 or more types. Further, by blending a dye or a pigment, the latent image in the exposed area can be visualized, and the influence of halation during exposure can be reduced. Furthermore, adhesiveness with a board | substrate can be improved by mix | blending an adhesion aid. The compounding quantity of a sensitizer is 50 mass parts or less normally with respect to 100 mass parts of resin (B).

  Examples of the alicyclic additive that can be added to the resist agent include an alicyclic additive having an acid dissociable group and an alicyclic additive having no acid dissociable group. Such an alicyclic additive is a component having an effect of further improving dry etching resistance, pattern shape, adhesion to a substrate, and the like. Specific examples of the alicyclic additive include 1-adamantanecarboxylic acid, 2-adamantanone, 1-adamantanecarboxylic acid t-butyl, 1-adamantanecarboxylic acid t-butoxycarbonylmethyl, 1-adamantanecarboxylic acid α-butyrolactone Ester, 1,3-adamantane dicarboxylate di-t-butyl, 1-adamantane acetate t-butyl, 1-adamantane acetate t-butoxycarbonylmethyl, 1,3-adamantane diacetate di-t-butyl, 2,5- Adamantane derivatives such as dimethyl-2,5-di (adamantylcarbonyloxy) hexane; deoxycholic acid t-butyl, deoxycholic acid t-butoxycarbonylmethyl, deoxycholic acid 2-ethoxyethyl, deoxycholic acid 2-cyclohexyloxy Ethyl, deoxycholic acid -Deoxycholic acid esters such as oxocyclohexyl, deoxycholic acid tetrahydropyranyl, deoxycholic acid mevalonolactone ester; lithocholic acid t-butyl, lithocholic acid t-butoxycarbonylmethyl, lithocholic acid 2-ethoxyethyl, lithocholic acid 2 -Lithocholic acid esters such as cyclohexyloxyethyl, lithocholic acid 3-oxocyclohexyl, lithocholic acid tetrahydropyranyl, lithocholic acid mevalonolactone ester; dimethyl adipate, diethyl adipate, dipropyl adipate, di-n-butyl adipate, Alkyl carboxylic acid esters such as di-t-butyl adipate; 3- [2-hydroxy-2,2-bis (trifluoromethyl) ethyl] tetracyclo [4.4.0.12,5.17,10] A dodecane etc. can be mentioned.

  These alicyclic additives can be used singly or in combination of two or more. The compounding quantity of an alicyclic additive is 50 mass parts or less normally with respect to 100 mass parts of resin (B), Preferably it is 30 mass parts or less. When the blending amount of the alicyclic additive is more than 50 parts by mass with respect to 100 parts by mass of the resin (B), the heat resistance as a resist tends to decrease. Furthermore, examples of additives other than the above include alkali-soluble resins, low-molecular alkali solubility control agents having an acid-dissociable protecting group, antihalation agents, storage stabilizers, antifoaming agents, and the like.

2. Pattern formation method:
(Formation of resist layer)
As shown in FIG. 1, on the substrate 1 such as a silicon wafer, a wafer coated with SiN or an organic antireflection film, etc., the above-mentioned resist agent is applied by an appropriate application means such as spin coating, casting coating, roll coating or the like. The resist layer 2 can be formed by applying. In addition, after apply | coating a resist agent, you may volatilize the solvent in a coating film by prebaking (PB) as needed. Although the prebaking heating conditions are appropriately selected depending on the composition of the resist agent, they are usually 30 to 200 ° C, preferably 50 to 150 ° C.

  In order to maximize the potential of the resist agent, an organic or inorganic antireflection film is formed on the substrate as disclosed in, for example, Japanese Patent Publication No. 6-12458. Is this. In order to prevent the influence of basic impurities contained in the environmental atmosphere, it is also preferable to provide a protective film on the resist layer as disclosed in, for example, Japanese Patent Laid-Open No. 5-188598. It is also preferable to perform both the formation of the antireflection film and the formation of the protective film.

(Negative latent image pattern forming process)
FIG. 2 is a cross-sectional view schematically showing an example of a state where exposure is performed with an exposure amount B. FIG. As shown in FIG. 2, in the negative latent image pattern forming process (hereinafter also simply referred to as “(1) process”), the first mask 11 having a predetermined opening pattern (first opening pattern) is interposed. Then, the resist layer 2 is exposed to radiation. The radiation dose (exposure dose) irradiated at this time is set to a higher exposure dose (exposure dose B) than the predetermined exposure dose range in which the characteristics of the resist agent change. By exposing in this way, as shown in FIG. 3, the exposed portion of the resist layer 2 becomes a latent image line portion (portion that has become alkali-insoluble or hardly soluble by exposure) 3a, and the non-exposed portion of the resist layer 2 becomes The latent image space portion 3b (alkali-soluble portion (resist layer 2)) is formed. Therefore, a negative latent image pattern 3 composed of the latent image line portion 3a and the latent image space portion 3b is formed.

  The radiation that can be used in the pattern forming method of the present embodiment is appropriately selected from visible rays, ultraviolet rays, far ultraviolet rays, X-rays, charged particle beams, and the like according to the type of acid generator contained in the resist agent. However, far ultraviolet rays typified by ArF excimer laser (wavelength 193 nm), KrF excimer laser (wavelength 248 nm) and the like are preferable, and ArF excimer laser (wavelength 193 nm) is particularly preferable. Note that heat treatment (PEB) is preferably performed after exposure. The heating condition of PEB is appropriately selected depending on the composition of the resist agent, but is usually 30 to 200 ° C, preferably 50 to 170 ° C.

(Positive type latent image pattern forming process)
FIG. 4 is a cross-sectional view schematically showing an example of the state of exposure with the exposure amount A. As shown in FIG. 4, in the positive latent image pattern forming process (hereinafter also simply referred to as “(2) process”), the second mask 12 having a predetermined opening pattern (second opening pattern) is interposed. Then, at least the resist layer 2 is exposed to radiation. At this time, the irradiation amount (exposure amount) of the irradiated radiation is set to a lower exposure amount (exposure amount A) than a predetermined exposure amount region in which the characteristics of the resist agent change. By exposing in this way, as shown in FIG. 5, the exposed portion of the resist layer 2 becomes a latent image line portion (portion that becomes alkali-insoluble or hardly soluble by exposure) 4a, and the unexposed portion of the resist layer 2 becomes The latent image space portion 4b (alkali-soluble portion (resist layer 2)) is formed. Therefore, a positive type latent image pattern 4 including the latent image line portion 4a and the latent image space portion 4b is formed.

  Note that heat treatment (PEB) is preferably performed after exposure. By this PEB, the dissociation reaction of the acid dissociable group in the resin component can be smoothly advanced. The heating condition of PEB is appropriately selected depending on the composition of the resist agent, but is usually 30 to 200 ° C, preferably 50 to 170 ° C.

  The opening pattern of the second mask 12 (see FIG. 4) used in the step (2) is different from the opening pattern of the first mask 11 (see FIG. 2) used in the step (1). That is, when a second mask having an opening pattern different from the opening pattern of the first mask is used in the step (2), the non-exposed portion of the resist layer that has not been exposed in the step (1) is converted in the step (2). It will be exposed. Thereby, a latent image pattern in which the negative latent image pattern 3 and the positive latent image pattern 4 are combined as shown in FIG. 5 can be formed.

(Development process)
In the development step (hereinafter, also simply referred to as “(3) step”), development is performed under alkaline conditions. This development is usually performed using a developer. Examples of the developer that can be used for development include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, and di-n-propylamine. , Triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- An alkaline aqueous solution in which at least one of alkaline compounds such as [4.3.0] -5-nonene is dissolved is preferable. The concentration of the alkaline aqueous solution is usually 10% by mass or less. When the concentration of the alkaline aqueous solution is more than 10% by mass, the non-exposed portion tends to be easily dissolved in the developer. In addition, after developing using alkaline aqueous solution, generally it wash | cleans with water and dries.

  An organic solvent can also be added to the alkaline aqueous solution (developer). Examples of the organic solvent that can be added include ketones such as acetone, methyl ethyl ketone, methyl i-butyl ketone, cyclopentanone, cyclohexanone, 3-methylcyclopentanone, and 2,6-dimethylcyclohexanone; methyl alcohol, ethyl alcohol , N-propyl alcohol, i-propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclopentanol, cyclohexanol, 1,4-hexanediol, 1,4-hexanedimethylol, and the like; tetrahydrofuran, dioxane Ethers such as ethyl acetate, n-butyl acetate, i-amyl acetate, aromatic hydrocarbons such as toluene and xylene, phenol, acetonylacetone, dimethylformamide, etc. That. These organic solvents can be used individually by 1 type or in combination of 2 or more types.

  The addition amount of the organic solvent is preferably 100 parts by volume or less with respect to 100 parts by volume of the alkaline aqueous solution. When the addition amount of the organic solvent is more than 100 parts by volume with respect to 100 parts by volume of the alkaline aqueous solution, the developability may be deteriorated and the development residue may be increased. An appropriate amount of a surfactant or the like can be added to the developer.

  By performing development, an alkali-soluble portion in the resist layer can be removed. Accordingly, as shown in FIG. 6, the first pattern 51 having the first line portion 51a and the first space portion 51b derived from the negative latent image pattern 3 (see FIG. 5), and the positive type A third pattern 50 having a second line portion 52a and a second space portion 52b derived from the latent image pattern 4 (see FIG. 5) can be formed.

  As described above, in the pattern forming method of the present invention, the irradiation amount (exposure amount) of the irradiated radiation is irradiated (exposed) in two stages to the resist layer formed on the substrate. Specifically, as described above, exposure is performed with the exposure amount B to form a negative latent image pattern (step (1)), and then exposure is performed with the exposure amount A to form a positive latent image pattern. ((2) step)) The order (first embodiment) can be cited as a preferred example. However, a positive latent image pattern is first formed by exposure with an exposure amount A (step (2)), and then a negative latent image pattern is formed by exposure with an exposure amount B (step (1)). )) The order (second embodiment) is also preferred. Hereinafter, specific contents of the second embodiment will be described.

(Second embodiment)
FIG. 7 is a cross-sectional view schematically showing another example of the state of exposure with the exposure amount A. As shown in FIG. 7, in the step (2) of the second embodiment, the resist layer 2 is irradiated with radiation through a second mask 22 having a predetermined opening pattern (second opening pattern). To expose. At this time, the irradiation amount (exposure amount) of the irradiated radiation is set to a lower exposure amount (exposure amount A) than a predetermined exposure amount region in which the characteristics of the resist agent change. By exposing in this way, as shown in FIG. 8, the exposed portion of the resist layer 2 becomes a latent image line portion (portion that becomes alkali-insoluble or hardly soluble by exposure) 14a, and the non-exposed portion of the resist layer 2 becomes The latent image space portion 14b (alkali-soluble portion (resist layer 2)) is formed. Therefore, a positive latent image pattern 14 composed of the latent image line portion 14a and the latent image space portion 41b is formed. Note that heat treatment (PEB) is preferably performed after exposure. The heating condition of PEB is appropriately selected depending on the composition of the resist agent, but is usually 30 to 200 ° C, preferably 50 to 170 ° C.

  FIG. 9 is a cross-sectional view schematically showing another example of the state of exposure with the exposure amount B. As shown in FIG. 9, in the step (1) of the second embodiment, radiation is applied to the resist layer 2 through the first mask 21 in which a predetermined opening pattern (first opening pattern) is formed. Irradiate and expose. The radiation dose (exposure dose) irradiated at this time is set to a higher exposure dose (exposure dose B) than the predetermined exposure dose range in which the characteristics of the resist agent change. By exposing in this way, as shown in FIG. 10, the exposed portion of the resist layer 2 becomes a latent image line portion (portion that becomes alkali-insoluble or hardly soluble by exposure) 13a, and the non-exposed portion of the resist layer 2 becomes The latent image space portion 13b (alkali-soluble portion (resist layer 2)) is formed. Therefore, a negative latent image pattern 13 composed of the latent image line portion 13a and the latent image space portion 13b is formed. Note that heat treatment (PEB) is preferably performed after exposure. The heating condition of PEB is appropriately selected depending on the composition of the resist agent, but is usually 30 to 200 ° C, preferably 50 to 170 ° C.

  The opening pattern of the second mask 22 (see FIG. 7) used in the step (2) of the second embodiment is different from the opening pattern of the first mask 21 (see FIG. 9) used in the step (1). is there. That is, when a second mask having an opening pattern different from the opening pattern of the first mask is used in the step (2), the exposed portion of the resist layer exposed in the step (2) is changed in the subsequent step (1). Further exposure will occur. As a result, a latent image pattern in which the positive latent image pattern 14 and the negative latent image pattern 13 are combined as shown in FIG. 10 can be formed.

  Thereafter, as in the first embodiment described above, development is usually performed using a developer under alkaline conditions. The types of developer that can be used are the same as those described above. By performing this development, the alkali-soluble portion in the resist layer can be removed. Accordingly, the first pattern 61 having the first line portion 61a and the first space portion 61b, which is derived from the negative latent image pattern 13 (see FIG. 10), as shown in FIG. A third pattern 60 having a second line 62 having a second line portion 62a and a second space portion 62b derived from the latent image pattern 14 (see FIG. 10) can be formed.

  The line widths of the first line portions 51a and 61a and the second line portions 52a and 62b to be formed as shown in FIGS. 6 and 11 are different depending on the type of radiation to be irradiated. For example, ArF excimer When a laser (wavelength: 193 nm) is used, the thickness is usually 50 to 500 nm, preferably 50 to 100 nm.

  According to the pattern forming method of the present invention, a fine pattern which has been difficult in the past can be easily formed by an exposure method using an ordinary ArF excimer laser without using an expensive apparatus such as an immersion exposure apparatus. be able to. Moreover, a fine pattern can be formed as compared with the conventional method only by performing the process of applying various materials containing a resin component such as a resist agent and the developing process only once. For this reason, the pattern forming method of the present invention is very simple and can be suitably incorporated into a semiconductor manufacturing process, and is extremely practical.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified. Moreover, the evaluation method of various characteristics is shown below.

[Pattern shape]: The pattern shape of the manufactured patterning substrate was evaluated according to the following criteria.
○: Both negative and positive patterns were formed by two exposures.
X: Only one pattern of negative type and positive type was formed, or neither pattern was formed.

(Preparation Example 1)
Resin (B-1) represented by the following formula (B-1) 100 parts, cross-linking agent (A-1) 7.5 parts, acid generator (C-1) 3.0 parts, acid diffusion controller ( D) 0.27 part, solvent (E-1) 960 part, and solvent (E-2) 410 part were mixed and the solution was obtained. The obtained solution was filtered with a membrane filter having a pore size of 200 nm to prepare a coating solution (resist agent (1)). The total solid concentration of the prepared resist agent (1) was about 7.5%. In addition, each component other than used resin (B-1) is as showing below.

<Crosslinking agent (A)>
(A-1): 1,3,5-triallyl-1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione

<Acid generator (C)>
(C-1): Triphenylsulfonium nonafluoro-n-butanesulfonate

<Acid diffusion control agent (D)>
(D-1): Nt-butoxycarbonylpyrrolidine

<Solvent (E)>
(E-1): Cyclohexanone (E-2): Propylene glycol monomethyl ether acetate

(Preparation Examples 2 to 5)
A coating solution (resist agents (2) to (5)) was prepared in the same manner as in Preparation Example 1 except that the formulation shown in Table 1 was used. The total solid concentration of each of the resist agents (2), (3) and (5) was about 7.0%. The total solid concentration of the resist agent (4) was about 7.5%. In addition, the structure of used resin (B-2), copolymer (F-1), and copolymer (F-2) is as showing below.

(Example 1)
Using a trade name “CLEAN TRACK ACT8” manufactured by Tokyo Electron Co., Ltd., a resist agent (1) was spin-coated on a silicon substrate, and then PB was performed at 100 ° C. for 60 seconds to form a resist film having a thickness of 150 nm. The ArF excimer laser exposure apparatus (trade name “NSR S306C”, manufactured by Nikon, illumination condition: NA 0.75 sigma 0.85) was used for the formed resist film, and the first exposure was performed through a mask. The exposure amount (irradiation amount) at this time was 30 mJ / cm ² . Next, the mask was exchanged and a second exposure was performed. The exposure amount (irradiation amount) at this time was 200 mJ / cm ² . After performing PEB at 120 ° C. for 60 seconds, a 2.38 mass% tetramethylammonium hydroxide aqueous solution was used and developed at 23 ° C. for 30 seconds to obtain a patterned substrate. The evaluation result of the pattern shape of the obtained patterning substrate was “◯”.

(Examples 2 and 3, Comparative Examples 1 and 2)
A patterned substrate was obtained in the same manner as in Example 1 except that PB and PEB were performed under the conditions shown in Table 2. Table 2 shows the evaluation results of the pattern shape of the obtained patterning substrate.

  The pattern forming method of the present invention is a technique that can be very suitably employed in the field of microfabrication represented by the manufacture of integrated circuit elements that are expected to become increasingly finer in the future.

It is sectional drawing which shows typically an example of the resist layer formed on the board | substrate. It is sectional drawing which shows typically an example of the state exposed with the exposure amount B. FIG. It is sectional drawing which shows typically an example of the state in which the negative type latent image pattern was formed. It is sectional drawing which shows typically an example of the state exposed with the exposure amount A. FIG. FIG. 5 is a cross-sectional view schematically showing an example of a state in which a negative latent image pattern and a positive latent image pattern are formed. It is sectional drawing which shows typically an example of the formed line and space pattern. It is sectional drawing which shows typically the other example of the state exposed with the exposure amount A. It is sectional drawing which shows typically an example of the state in which the positive type latent image pattern was formed. It is sectional drawing which shows typically the other example of the state exposed with the exposure amount B. FIG. It is sectional drawing which shows typically the other example in the state in which the negative type latent image pattern and the positive type latent image pattern were formed. It is sectional drawing which shows typically the other example of the formed line and space pattern. It is a graph which shows the relationship between the exposure amount and resist layer thickness of the resist agent used with the pattern formation method of this invention.

Explanation of symbols

1: substrate, 2: resist layer, 3a, 4a, 13a, 14a: latent image line portion, 3b, 4b, 13b, 14b: latent image space portion, 3, 13: negative latent image pattern, 4, 14: Positive latent image pattern, 11, 21: first mask, 12, 22: second mask, 50, 60: third pattern, 51a, 61a: first line portion, 51b, 61b: first Space part 51, 61: first pattern 52a, 62a: second line part 52b, 62b: second space part 52, 62: second pattern

Claims (5)

The resist layer formed on the substrate is made of a radiation-sensitive resin composition that becomes alkali-soluble at exposure amount A and becomes insoluble or hardly soluble at exposure amount B (however, exposure amount A <exposure amount B). ,
(1) a negative latent image pattern forming step of forming a negative latent image pattern by exposing with an exposure amount B through a first mask having a first opening pattern;
(2) a positive latent image pattern forming step of forming a positive latent image pattern by exposing with an exposure amount A through a second mask having a second opening pattern different from the first opening pattern;
(3) Developing under alkaline conditions to form a third pattern having a first pattern derived from the negative latent image pattern and a second pattern derived from the positive latent image pattern A development process to
A pattern forming method comprising:   The pattern forming method according to claim 1, wherein the positive latent image pattern forming step is performed after the negative latent image pattern forming step.   The pattern forming method according to claim 2, wherein a portion of the resist layer that has not been exposed in the negative latent image pattern forming step is exposed in the positive latent image pattern forming step.   The pattern forming method according to claim 1, wherein the negative latent image pattern forming step is performed after the positive latent image pattern forming step.   The pattern forming method according to claim 4, wherein a portion of the resist layer exposed in the positive latent image pattern forming step is further exposed in the negative latent image pattern forming step.

Images