JP2007065503A - Resist composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a resist composition having dry etching resistance, that is less likely to cause collapse of a resist pattern, capable of preventing acid leaching, and is superior in basic properties as a resist. <P>SOLUTION: The resist composition contains a polymer, having at least one kind of repeating unit derived from an acrylic ester derivative or the like and having an acid dissociable group which increases the solubility with respect to alkali developer by the action of an acid, and a crosslinking agent or a crosslinking initiator. The polymer, having the acid dissociable group, is a compound containing an oxygen-containing monocyclic derivative or a sulfur-containing cyclic derivative inside a molecule. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a resist composition, and more particularly to a chemically amplified resist composition.

  In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, miniaturization has rapidly progressed due to advances in lithography technology. As a technique for miniaturization, the wavelength of an exposure light source is generally shortened. Specifically, ultraviolet rays typified by g-line and i-line have been used in the past, but now far-ultraviolet rays typified by KrF excimer laser (248 nm) and ArF excimer laser (193 nm) have been introduced into mass production. ing.

  A resist using these as a radiation source is required to have high resolution and high sensitivity capable of reproducing a pattern with a fine dimension. As one of the resists satisfying such conditions, a chemically amplified positive resist composition containing a base resin whose alkali solubility is increased by the action of an acid and an acid generator that generates an acid upon exposure is known.

  In a chemically amplified positive resist, an acid is generated from an acid generator in the resist by exposure, and a reaction between the acid and the base resin occurs. The acid-catalyzed chain reaction proceeds by baking after exposure, and the solubility of the base resin in the alkaline solution changes. Thereby, very high sensitivity can be obtained as compared with the conventional non-chemically amplified resist.

  In addition to resolution, resists are required to have various characteristics such as sensitivity, dry etch resistance, low line edge roughness of the pattern, and low density dependency of the pattern. In particular, the finer the pattern, the higher the aspect ratio of the resist. Furthermore, in order to prevent the resist pattern from collapsing, it is necessary to reduce the film thickness of the resist, so that resistance to dry etching of the resist is required.

In order to prevent resist pattern collapse, a method is known in which a surfactant having a low surface tension is used for rinsing after development (see, for example, Patent Document 1). Further, development for preventing pattern collapse and improving dry etching resistance from the structure of the acid-dissociable group-containing polymer has been carried out (see, for example, Patent Document 2).
JP 2004-184648 A JP 2005-31564 A

  However, the method disclosed in Patent Document 1 has a problem that the number of steps is larger than that of the original lithography process, and time and cost are required in semiconductor manufacturing. In addition, the method disclosed in Patent Document 2 is insufficient to satisfy various characteristics such as sensitivity and resolution originally required for a resist, and to sufficiently prevent pattern collapse and improve dry etching resistance. There is a problem.

  The present invention solves the above-mentioned conventional problems, has dry etch resistance, resist patterns are not easily collapsed, can prevent acid elution, sensitivity, resolution, dry etch resistance, pattern shape, line edge roughness, etc. An object of the present invention is to realize a resist composition having excellent basic characteristics as a resist.

  In order to achieve the above object, the present invention comprises a resist composition containing a polymer that forms a crosslink within or between molecules.

  Specifically, the resist composition of the present invention comprises (A) a polymer having at least one repeating unit represented by the general formula (I) and having an acid-dissociable group that increases the solubility in an alkali developer and ( B) A crosslinking agent or crosslinking initiator is contained, and the polymer (A) is a compound containing an oxygen-containing monocyclic derivative or a sulfur-containing ring derivative in the molecule.

  Since the resist composition of the present invention contains (A) a polymer and (C) a crosslinking agent or a crosslinking initiator, the (A) polymer causes a crosslinking reaction by heating at an arbitrary temperature. Accordingly, the unexposed portion of the resist pattern obtained by the subsequent exposure processing and development processing is hard to fall even in a resist pattern having a high aspect ratio because the resin is cured by a crosslinking reaction. Further, since the molecular weight of the resin in the unexposed area is increased by the crosslinking reaction, the dry etching resistance is also improved. On the other hand, since the exposed portion undergoes a deprotection reaction together with the crosslinkable group, sensitivity and resolution are not affected by the crosslinkage, and characteristics equivalent to those of conventional resist compositions can be obtained. As a result, in addition to the various characteristics of the resist, various characteristics such as improved dry etch resistance, prevention of pattern collapse and prevention of acid elution can be satisfied.

In the resist composition of the present invention, in general formula (I), R ₁ is a hydrogen atom or an alkyl group having 4 or less carbon atoms, and R ₂ is an isobutyl group, a tert-butyl group, a tert-amyl group, a benzyl group, Group, cyclohexyl group, anthracenyl group, hydroxyethyl group, cinnamyl group, adamantyl group, methyladamantyl group, ethyladamantyl group, isobornyl group, ethoxyethyl group, methoxypropyl group, methoxyethoxyl group, oxotetrahydrofuran group, hydroxytrimethylpropyl group, It is preferably any one group selected from the group consisting of an oxo-oxatricyclononyl group, a naphthyl group, a phenylethyl group, and a phenyl group. .

  In the resist composition of the present invention, the crosslinking agent or crosslinking initiator (B) is preferably a compound containing an amine. By setting it as such a structure, bridge | crosslinking can be reliably formed in the molecule | numerator of a polymer (A) or between molecules.

  The resist composition of the present invention preferably further contains an additive. Moreover, it is preferable that the resist composition of this invention further contains a solvent.

  The resist composition of the present invention preferably further contains an acid generator that generates an acid upon irradiation with light or radiation.

  According to the resist composition of the present invention, resist having dry etch resistance, resist pattern is not easily collapsed, acid elution can be prevented, and sensitivity, resolution, dry etch resistance, pattern shape, line edge roughness, and the like are resisted. As a result, a resist composition having excellent basic characteristics can be realized.

  Below, the compound used for this invention is demonstrated in detail.

-Polymer having acid dissociable group (component A)-
A polymer (A) is a polymer which has an acid dissociable group which has a repeating unit represented by general formula (I), and the solubility with respect to an alkali developing solution increases. Furthermore, the polymer (A) is a polymer that can form crosslinks within or between molecules by a cross-linking agent or a cross-linking initiator described later.

Specifically, the polymer (A) contains at least one repeating unit selected from the group represented by the formula (I). In the formula (I), R ₁ is selected from the group consisting of a hydrogen atom and a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, R ₂ is an isobutyl group, tert-butyl group, tert-amyl group, benzyl group, cyclohexyl group, anthracenyl group, hydroxyethyl group, cinnamyl group, adamantyl group, methyladamantyl group, ethyladamantyl group, isobornyl group, ethoxyethyl group, methoxypropyl group, methoxyethoxyl Selected from the group consisting of a group, an oxotetrahydrofuran group, a hydroxytrimethylpropyl group, an oxo-oxatricyclononyl group, a naphthyl group, a phenylethyl group, a phenyl group and the like.

Furthermore, the polymer (A) includes at least one repeating unit in which R _{2 in the} general formula (I) is an oxygen-containing monocyclic derivative or a sulfur-containing monocyclic derivative. Examples of oxygen-containing monocyclic derivatives include ethylene oxide (oxirane), propylene oxide (methyl oxirane), styrene oxide (phenyl oxirane), stilbene oxide (1,2-diphenyl oxirane), allene oxide (methylidene oxirane), and glycidyl (oxy). Ranylmethyl), glycidol (oxiranylmethanol), glycidic acid (oxirane carboxylic acid), epichlorohydrin ((chloromethyl) oxirane), epibromohydrin ((bromomethyl) oxirane), epicyanohydrin (oxiranyl) Acetonitrile) 3-membered ring derivative, trimethylene oxide (oxetane), β-propiolactone (oxetane-2-one, propano-3-lactone), diketene (4-methylideneoxetane-2-one), malon 4-membered ring derivative anhydride (oxetane-2,4-dione) and the like.

  Diglycolic anhydride (1,4-dioxane-2,6-dione), lactide, dilactide (3,6-dimethyl-1,4-dioxane-2,5-dione), paraaldehyde (2,4) , 6-trimethyl-1,3,5-trioxane) and 6-membered ring derivatives of siamellid (1,3,5-trioxane-2,4,6-triimine).

  ε-caprolactone (oxepan-2-one, hexano-6-lactone), exaltolide (oxacyclohexadecan-2-one, pentadecano-15-lactone), 12-crown-4 (1,4,7,10-tetraoxa Cyclododecane), 15-crown-5 (1,4,7,10,13-pentaoxacyclopentadecane), 18-crown-6 (1,4,7,10,13,16-hexaoxacyclooctadecane) It may be a 7-membered or higher derivative.

  Furan, furyl (furanyl), furfuryl (2-furylmethyl), furfurylidene (2-furylmethylidene), furfurylidine (2-furylmethylidyne), furfuryl alcohol (furan-2-methanol), furfural (furan-2-carba) Rudehydr), 2,2′-furyl (di (2-furyl) ethanedione), 2,2′-furoin (1,2-di (2-furyl) -2-hydroxyethane-1-one), furoic acid ( 2- to 3-) (furancarboxylic acid), furoyl (2- to 3-) (furancarbonyl), pyromucic acid (furan-2-carboxylic acid), pyromucyl (furan-2-carbonyl), dehydromucic acid ( 2,5-dicarboxylic acid), furylic acid (di (2-furyl) hydroxyacetic acid), γ-butyrolactone (tetrahydrofuran-2-one, porcine) No-4-lactone), γ-valerolactone (5-methyltetrahydrofuran-2-one, pentano-4-lactone), γ-caprolactone (5-ethyltetrahydrofuran-2-one, hexano-4-lactone), pantolactone (3-hydroxy-4,4-dimethyltetrahydrofuran-2-one), homoserine lactone (3-aminotetrahydrofuran-2-one), tetronic acid (tetrahydrofuran-2,4-dione), succinic anhydride (tetrahydrofuran-2, 5-dione), maleic anhydride (2,5-dihydrofuran-2,5-dione), citraconic anhydride (3-methyl-2,5-dihydrofuran-2,5-dione), muscarinic ((2S , 4R, 5S) -4-hydroxy-N, N, N, 5-tetramethyltetrahydrofuran-2-me Tanaminium), 2H-furylium (2H-1λ4-furan-1-ylium), 2H-pyran, pyrone (2- or 4-) (pyranone), maltol (3-hydroxy-2-methyl-4H-pyran-4- ON), kojic acid (5-hydroxy-2- (hydroxymethyl) -4H-pyran-4-one), dehydroacetic acid (3-acetyl-6-methyl-3,4-dihydro-2H-pyran-2,4) -Dione), δ-valerolactone (tetrahydropyran-2-one, pentano-5-lactone), δ-caprolactone (6-methyltetrahydropyran-2-one, hexano-5-lactone), mevalonolactone (4-hydroxy- 4-methyltetrahydropyran-2-one), glutaric anhydride (tetrahydropyran-2,6-dione), coumaric acid (2-o Xo-2H-pyran-5-carboxylic acid), keridonic acid (4-oxo-4H-pyran-2,6-dicarboxylic acid), meconic acid (3-hydroxy-4-oxo-4H-pyran-2,6- Dicarboxylic acid), secoroganine (methyl = (2S, 3R, 4S) -4- (formylmethyl) -2- (β-D-glucopyranosyloxy) -3-vinyl-3,4-dihydro-2H-pyran -5-carboxylate, (2S, 3R, 4S) -4- (formylmethyl) -2- (β-D-glucopyranosyloxy) -3-vinyl-3,4-dihydro-2H-pyran-5 -Carboxylic acid methyl), secoroganoic acid ((2S, 3R, 4S) -4- (formylmethyl) -2- (β-D-glucopyranosyloxy) -3-vinyl-3,4-dihydro-2H- Pyran-5-carboxylic acid), pyririu Or the like.

  Examples of the oxygen-containing monocyclic derivative include ethylene sulfide (thiirane), trimethylene sulfide (thietane), thioctic acid, α-lipoic acid, lipoic acid (1,2-dithiolane-3-pentanoic acid), tetrathiafulvalene (2 , 2′-bi (1,3-dithiol-2-ylidene)), lenthionine (1,2,3,5,6-pentathiepane), thiophene, thienyl (2- to 3-) (thiophenyl), tenenyl ( 2-thienylmethyl), tenylidene (2-thienylmethylidene), tenilidine (2-thienylmethylidyne), tenoic acid (2- to 3-) (thiophenecarboxylic acid), tenoyl (2- to 3-) (thiophenecarbonyl) ), Tetramethylene sulfide (tetrahydrothiophene, thiolane), tetramethylene sulfoxide (tetrahydrothiop) Down 1-oxide), sulfolane, tetramethylene sulfone (tetrahydrothiophene 1,1-dioxide), 3-sulfolene (2,5-dihydro-thiophene 1,1-dioxide), 2H-thiopyran, thiopyrylium and the like.

  An example of a repeating unit containing an oxygen-containing monocyclic derivative or a sulfur-containing monocyclic derivative is shown in Formula (II). X in the formula (II) may be either an oxygen atom or a sulfur atom.

-Crosslinking agent or crosslinking initiator (B)-
The crosslinking agent and crosslinking initiator (B) may be any compound that can cleave and crosslink the oxygen-containing monocyclic derivative or sulfur-containing monocyclic derivative of the polymer (A). Usually, in the crosslinking reaction, heating at 50 ° C. to 200 ° C. is performed, preferably heating at 70 ° C. to 180 ° C. is performed.

  The structure of the crosslinking agent or crosslinking initiator (B) is specifically a compound having an amino group and may be any of the following compounds. Ethylazane, ethanamine, ethylamine, phenylazane, benzeneamine, phenylamine, aniline, benzylazane, 1-phenylmethanamine, benzylamine, benzenemethanamine, 1-benzofuran-2-ylazane, 1-benzofuran-2-amine, 1 -Benzofuran-2-ylamine, 2-benzofuranamine, 4-quinolylazane, quinolin-4-amine, 4-quinolylamine, 4-quinolinamine, 4-aminoquinoline, ethylenebis (azane), ethane-1,2-diamine, Ethylenediamine, 1,2-ethanediamine, pentane-1,2,5-triyltris (Azan), pentane-1,2,5-triamine, pentane-1,2,5-triyltriamine, 1,2,5- Pentanetriamine, benzene-1, , 4,5-tetrayltetrakis (azane), benzene-1,2,4,5-tetraamine, benzene-1,2,4,5-tetrayltetraamine, 1,2,4,5-benzenetetraamine Primary amine compounds such as

  Further, diethylazane, diethylamine, N-ethylethanamine, butyl (ethyl) methylazane, N-ethyl-N-methylbutan-1-amine, butyl (ethyl) methylamine, N-ethyl-N-methylbutylamine, N-ethyl Secondary amine compounds such as -N-methyl-1-butanamine, N-diethylcyclohexylamine, N-ethyldicyclohexylamine, N, N-dimethylhexylamine and N-methyldicyclohexylamine may also be used.

  Triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, cyclohexyldimethylamine, tricyclohexylamine Tri (cyclo) alkylamines such as; alkanolamines such as triethanolamine and diethanolaniline; N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetrakis (2- Hydroxypropyl) ethylenediamine, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzenetetramethylenediamine, 2,2-bis (4-aminophenyl) propane, 2- (3-aminophenyl) ) -2- (4-aminophenyl) propane, 2- (4- Minophenyl) -2- (3-hydroxyphenyl) propane, 2- (4-aminophenyl) -2- (4-hydroxyphenyl) propane, 1,4-bis [1- (4-aminophenyl) -1-methyl Tertiary amine compounds such as ethyl] benzene, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzene, bis (2-dimethylaminoethyl) ether, bis (2-diethylaminoethyl) ether It may be.

  Triamines such as diethylenetriamine, 4-dodecyldiaeylenetriamine, bis (hexamethylene) triamine, 1,2,4-benzenetriamine, 1,1,4,7,7-pentamethyldiethylenetriamine may be used.

N- (2-aminoethyl) -1,3-propanediamine, N-isopropylethylenediamine, N-isopropyl-1,3-propanediamine, N-ethylethylenediamine, 4- (N-ethyl-N-2-hydroxyethyl) ) -2 Methylphenyldiamine, Ethylenediamine, 4- (4-Ethoxyphenylazo) -m-phenylenediamine, m-xylenediamine, chloro-phenylenediamine, dimethylethyldiamine, 1,4-diazabicyclo [2,2,2] Diamines such as octane may be used. The amount of the crosslinking agent used is 0.01 to 10 parts by weight, preferably 0.1 to 1 part by weight, per 100 parts by weight of the solid in the composition. If the amount of the crosslinking agent used is small, the crosslinking reaction of the acid-dissociable group-containing polymer does not proceed, and desired properties cannot be obtained. On the other hand, if the amount is too large, the cross-linking reaction of the acid-dissociable group-containing polymer proceeds excessively, resulting in poor sensitivity.

-Acid generator-
An acid generator is a compound that generates acid upon exposure to high-energy light or high-energy radiation. Preferred acid generators include sulfonium salts, iodonium salts, sulfonyldiazomethane and N-sulfonyloxyimide. These acid generators can be used alone or in admixture of two or more. Content of an acid generator is 0.1-25 weight part per 100 weight part of solids in a composition, Preferably it is 1-15 weight part. In this case, if the amount of the acid generator used is too small, the sensitivity and resolution are lowered. On the other hand, when the amount is too large, transparency to radiation is lowered, and it tends to be difficult to obtain a rectangular resist pattern.

  Specific examples of preferred acid generators include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium 2-bicyclo [2.2. 1] hept-2-yl-1,1,2,2 tetrafluoroethanesulfonate, triphenylsulfonium camphorsulfonate, and the like.

  Also, 4-cyclohexylphenyl diphenylsulfonium trifluoromethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium perfluoro-n-, which are 4-cyclohexylphenyldiphenylsulfonium salt compounds. Octanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium-2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium camphorsulfonate, etc. It may be.

  4-cyclohexylphenyldiphenylsulfonium salt compounds, 4-methanesulfonylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium perfluoro-n-octane Sulfonate, 4-methanesulfonylphenyldiphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium camphorsulfonate, etc. May be.

  Diphenyliodonium salt compounds such as diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1] hept-2-yl -1,1,2,2-tetrafluoroethane sulfonate, diphenyl iodonium camphor sulfonate, and the like may be used.

  Bis (4-t-butylphenyl) iodonium salt compounds, 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-tetra Fluoroethanesulfonate, bis (4-t-butylphenyl) iodonium camphorsulfonate, and the like may be used.

  1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium salt compound, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4- n-butoxynaphthalen-1-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- ( 4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (4-n -Butoxynaphthalen-1-yl) tetrahydrothiophenium camphorsulfonate, etc. It may be.

  1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium trifluoromethanesulfonate, which is a 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium salt compound, n-butoxynaphthalen-2-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- ( 6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (6-n -Butoxynaphthalen-2-yl) tetrahydrothiophenium camphorsulfonate It may be.

  1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium salt compound, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (3 5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- ( 3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (3,5 -Dimethyl-4-hydroxyphenyl) tetrahydrothiophenium It may be a far-sulfonates.

  N- (trifluoromethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2, such as a bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide compound , 3-dicarboximide, N- (nonafluoro-n-butanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (perfluoro-n-octanesulfonyl) Oxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (2-bicyclo [2.2.1] hept-2-yl-1,1,2,2 -Tetrafluoroethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (2- (3-tetracyclo [4.4.0.1.1.1] dodecanyl) -1 1-difluoroethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (camphorsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2 , 3-dicarboximide or the like.

-Additives-
The resist composition of the present invention includes an acid diffusion controller, an alicyclic additive having an acid dissociable group, an alicyclic additive not having an acid dissociable group, a surfactant, and a sensitizer as necessary. You may mix | blend various additives, such as.

  The acid diffusion control agent is a component having an action of controlling a diffusion phenomenon of an acid generated from an acid generator upon irradiation in a resist film and suppressing an undesirable chemical reaction in a non-irradiated region. By blending such an acid diffusion controller, the storage stability of the resulting radiation-sensitive resin composition is improved, and the resolution as a resist is further improved. Furthermore, a change in the line width of the resist pattern due to fluctuations in the holding time (PED) from irradiation to development processing can be suppressed, and a composition excellent in process stability can be obtained.

  As the acid diffusion controller, a nitrogen-containing organic compound whose basicity does not change by irradiation or heat treatment during the resist pattern forming process is preferable. Examples of such nitrogen-containing organic compounds include “tertiary amine compounds”, “amide group-containing compounds”, “quaternary ammonium hydroxide compounds”, “nitrogen-containing heterocyclic compounds”, and the like.

  Examples of the “tertiary amine compound” include triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n. -Tri (cyclo) alkylamines such as octylamine, cyclohexyldimethylamine, tricyclohexylamine; alkanolamines such as triethanolamine, diethanolaniline; N, N, N ', N'-tetramethylethylenediamine, N, N , N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzenetetramethylenediamine, 2,2-bis (4-amino) Phenyl) 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-methylethyl] benzene, bis (2-dimethylaminoethyl) ether, bis (2 -Diethylaminoethyl) ether and the like.

  Examples of the “amide group-containing compound” include Nt-butoxycarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-n-decylamine, N- t-butoxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-N-methyl-1-adamantylamine, 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-butoxycarbonylhexamethyl Range amine, 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-phenylbenz Imidazole, Nt-butoxycarbonyl-pyrrolidine, Nt-butoxycarbonyl-piperidine, Nt-butoxy In addition to Nt-butoxycarbonyl group-containing amino compounds such as carbonyl-4-hydroxy-piperidine, Nt-butoxycarbonyl-morpholine, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methyl Examples include acetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone and the like.

  Examples of the “quaternary ammonium hydroxide compound” include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetra-n-propylammonium hydroxide, tetra-n-butylammonium hydroxide, and the like. Examples of the “nitrogen-containing heterocyclic compound” include imidazoles such as imidazole, 4-methylimidazole, 1-benzyl-2-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole; In addition to piperazines such as piperazine and 1- (2-hydroxyethyl) piperazine, pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, Examples include 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane.

  Of the nitrogen-containing heterocyclic compounds, tertiary amine compounds, amide group-containing compounds, and nitrogen-containing heterocyclic compounds are preferred, and among the amide group-containing compounds, Nt-butoxycarbonyl group-containing amino compounds are preferred, and nitrogen-containing compounds are preferred. Among the complex compounds, imidazoles are preferable.

  The acid diffusion controller can be used alone or in admixture of two or more. The compounding amount of the acid diffusion controller is usually 15 parts by weight or less, preferably 10 parts by weight or less, and more preferably 5 parts by weight or less with respect to 100 parts by weight of the acrylic polymer. In this case, when the compounding amount of the acid diffusion controller exceeds 15 parts by weight, the sensitivity as a resist and the developability of the radiation irradiated part tend to be lowered. If the amount of the acid diffusion controller is less than 0.001 part by weight, the pattern shape and dimensional fidelity as a resist may be lowered depending on the process conditions.

  In addition, an alicyclic additive having an acid dissociable group or an alicyclic additive not having an acid dissociable group is a component that further improves dry etching resistance, pattern shape, adhesion to a substrate, and the like. is there.

  Examples of such alicyclic additives include 1-adamantanecarboxylic acid t-butyl, 1-adamantanecarboxylic acid t-butoxycarbonylmethyl, 1-adamantanecarboxylic acid α-butyrolactone ester, 1,3-adamantane dicarboxylic acid diester. -T-butyl, 1-adamantane acetate t-butyl, 1-adamantane acetate t-butoxycarbonylmethyl, 1,3-adamantanediacetate di-t-butyl, 2,5-dimethyl-2,5-di (adamantylcarbonyl There are adamantane derivatives such as oxy) hexane.

  Also, t-butyl deoxycholate, t-butoxycarbonylmethyl deoxycholate, 2-ethoxyethyl deoxycholate, 2-cyclohexyloxyethyl deoxycholate, 3-oxocyclohexyl deoxycholate, tetrahydropyranyl deoxycholate, Deoxycholic acid esters such as deoxycholic acid mevalonolactone ester; t-butyl lithocholic acid, t-butoxycarbonylmethyl lithocholic acid, 2-ethoxyethyl lithocholic acid, 2-cyclohexyloxyethyl lithocholic acid, 3-oxocyclohexyl lithocholic acid And lithocholic acid esters such as tetrahydropyranyl lithocholic acid and mevalonolactone ester of lithocholic acid.

  Alkyl carboxylic acid esters such as dimethyl adipate, diethyl adipate, dipropyl adipate, di-n-butyl adipate, and di-t-butyl adipate may also be used.

  These alicyclic additives can be used alone or in admixture of two or more. The compounding quantity of an alicyclic additive is 50 parts weight or less normally with respect to 100 weight part of acrylic polymers, Preferably it is 30 parts weight or less. In this case, when the blending amount of the alicyclic additive exceeds 50 parts by weight, the heat resistance as a resist tends to decrease.

  Further, the surfactant as an additive is a component having an effect of improving coating property, 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. And nonionic surfactants such as polyethylene glycol distearate.

  Further, the sensitizer as an additive has an action of absorbing radiation energy and transmitting the energy to the acid generator, thereby increasing the amount of acid generated. The radiation-sensitive resin composition It has the effect of improving the apparent sensitivity.

  Examples of such a sensitizer include carbazoles, benzophenones, rose bengals, anthracenes, phenols and the like.

These sensitizers can be used alone or in admixture of two or more. The blending amount of the sensitizer is preferably 50 parts by weight or less with respect to 100 parts by weight of the acrylic polymer.
Further, additives other than those mentioned above include antihalation agents, adhesion assistants, storage stabilizers, antifoaming agents and the like.

-Solvent-
The resist fat composition of the present invention is usually dissolved in a solvent so that the total solid content is usually 3 to 50% by weight, preferably 5 to 25% by weight. The solution is prepared by filtering with a filter of about 2 μm.

  Examples of the solvent used for preparing the solution include linear or branched ketones such as 2-pentanone, 2-hexanone, 2-heptanone, and 2-octanone; cyclic ketones such as cyclopentanone and cyclohexanone. Propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate; 2-hydroxypropionic acid alkyls such as methyl 2-hydroxypropionate and ethyl 2-hydroxypropionate; 3-methoxy Examples thereof include alkyl 3-alkoxypropionates such as methyl propionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate and ethyl 3-ethoxypropionate.

  Also, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, n-butyl acetate, pyrubin Examples thereof include methyl acid, ethyl pyruvate, N-methylpyrrolidone, and γ-butyrolactone.

  These solvents can be used alone or in admixture of two or more, but propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, 2-heptanone, cyclohexanone, γ-butyrolactone, ethyl 2-hydroxypropionate, 3-ethoxy It is preferable to contain at least one selected from ethyl propionate. However, cyclohexanone is an effective solvent from the viewpoint of solubility, but its use is preferably avoided as much as possible because of its toxicity.

  Below, the formation method of the resist pattern by the resist composition of this invention is demonstrated.

  The resist pattern forming method includes a step of forming a resist film by heating after applying a resist composition as a solution, a step of performing pattern exposure by selectively irradiating exposure light to the resist film, and pattern exposure. And developing the resist film to form a resist pattern.

  When forming a resist pattern from the resist composition of the present invention, a solution in which the resist composition is dissolved is coated with, for example, a silicon wafer or aluminum by an appropriate application means such as spin coating, cast coating, or roll coating. A resist film is formed by coating on a wafer or a substrate on which a lower layer film has been formed in advance, and a predetermined resist pattern is formed after performing a heat treatment (hereinafter referred to as PB treatment) in some cases. Then, the resist film is exposed to light.

  The radiation used at that time is preferably radiation having a wavelength of 200 nm or less, and particularly ArF excimer laser (wavelength 193 nm) is preferred. The PB treatment temperature is 50 ° C to 200 ° C, preferably 70 ° C to 180 ° C. By this PB treatment, a crosslinking reaction is caused in the resist, the molecular weight of the entire resist is increased, and the resin is cured. For example, the compound represented by the formula (III) and octamethylenediamine cause the reaction represented by the formula (IV). For this reason, the resist pattern obtained by subsequent exposure, post-exposure bake, and development processing is not easily collapsed, and etching resistance is obtained.

  When using the resist composition of the present invention, it is preferable to perform a heat treatment (hereinafter referred to as PEB treatment) after exposure. The heating conditions for the PEB treatment vary depending on the composition of the radiation sensitive resin composition, but are usually 30 to 200 ° C, preferably 50 to 170 ° C. At this time, the exposed portion undergoes a deprotection reaction, but since the entire crosslinked portion is detached, subsequent development characteristics are not affected. Further, an organic or inorganic lower layer film can be formed on the substrate to be used, and a protective film can be provided on the resist film.

  Next, a predetermined resist pattern is formed by developing the exposed resist film. Examples of the developer used for development include sodium hydroxide, potassium hydroxide, aqueous ammonia, ethylamine, diethylamine, triethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo. An alkaline aqueous solution in which at least one of alkaline compounds such as [5.4.0] -7-undecene and 1,5-diazabicyclo- [4.3.0] -5-nonene is dissolved is preferable. Further, an organic solvent or a surfactant can be added to the developer composed of the alkaline aqueous solution.

In addition, after developing with the developing solution which consists of alkaline aqueous solution, generally it wash | cleans with water and dries.

(One embodiment)
An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a step of forming a resist pattern from the resist composition of this embodiment.

In this embodiment, the resist composition is a polymer in which the polymer (A) is represented by the formula (V), and the crosslinking agent (B) is 1,4-diazabicyclo [2,2,2] octane. It contains triphenylsulfonium nonaflate as an acid generator. In this case, a positive resist is formed.

  As shown in FIG. 1A, the chemically amplified resist composition of this embodiment is applied on a substrate 11 to form a resist film 12 having a thickness of 0.20 to 1.0 μm. Here, the baking temperature after application is set to 50 ° C to 200 ° C. Preferably, the temperature is set to 70 ° C to 180 ° C. As shown in FIG. 1B, a crosslinked resist film 13 that has undergone intramolecular or intermolecular crosslinking is formed by baking after coating.

  Next, as shown in FIG. 1C, pattern exposure is performed by irradiating the cross-linked resist film 13 with exposure light 15 through a mask 14. Thereby, as shown in FIG.1 (d), the unexposed part 13b and the exposed part 13a are formed in the bridge | crosslinking resist film 13. FIG.

  Next, the crosslinked resist film 13 subjected to pattern exposure as shown in FIG. 1E is heated with a hot plate, and then 2.38 wt% tetramethylammonium hydroxide developer (alkaline developer). The exposed portion 13a is dissolved and removed, and the unexposed portion 13b is left as a resist pattern 16.

For exposure, g-line, I-line, KrF excimer laser, ArF excimer laser, F ₂ excimer laser, electron beam, X-ray, EUV or the like can be used.

  Conditions such as temperature and time in various steps such as baking after exposure and development treatment may be arbitrary.

  Since the resist pattern 16 remaining on the wafer after the development processing is hardened, the resist pattern 16 retains characteristics superior in resist collapse prevention, etching resistance, and acid elution resistance than conventional acid-dissociable group-containing polymers. Yes.

  In the present embodiment, an example of a positive resist is shown, but the present invention is not limited to this.

  The resist composition of the present invention has dry etch resistance, resist patterns are not easily collapsed, and can prevent acid elution, as well as resists such as sensitivity, resolution, dry etch resistance, pattern shape, and line edge roughness. It has an effect that a resist composition having excellent basic characteristics can be realized, and is useful as a resist composition, particularly a chemically amplified resist composition. .

It is sectional drawing which shows the example of formation of the resist pattern by the resist composition which concerns on one Embodiment of this invention in process order.

Explanation of symbols

11 Substrate 12 Resist film 13 Cross-linked resist film 13a Exposed portion 13b Unexposed portion 14 Mask 15 Exposure light 16 Resist pattern

Claims (6)

(A) a polymer having at least one repeating unit represented by formula (I) and having an acid-dissociable group that increases the solubility in an alkali developer; and (B) a crosslinking agent or a crosslinking initiator. ,
The resist composition, wherein the polymer (A) is a compound containing an oxygen-containing monocyclic derivative or a sulfur-containing ring derivative in a molecule.

In the general formula (I), R ₁ is a hydrogen atom or an alkyl group having 4 or less carbon atoms, and R ₂ is an isobutyl group, a tert-butyl group, a tert-amyl group, a benzyl group, a cyclohexyl group, or an anthracenyl group. , Hydroxyethyl group, cinnamyl group, adamantyl group, methyladamantyl group, ethyladamantyl group, isobornyl group, ethoxyethyl group, methoxypropyl group, methoxyethoxyl group, oxotetrahydrofuran group, hydroxytrimethylpropyl group, oxo-oxatricyclononyl group The resist composition according to claim 1, wherein the resist composition is any one group selected from the group consisting of naphthyl group, phenylethyl group, and phenyl group.   The resist composition according to claim 1, wherein the crosslinking agent or crosslinking initiator (B) is an amine-containing compound.   The resist composition according to any one of claims 1 to 3, further comprising an additive.   The resist composition according to any one of claims 1 to 4, further comprising a solvent. The resist composition according to claim 1, further comprising an acid generator that generates an acid upon irradiation with light or radiation.

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