WO2000057249A1

WO2000057249A1 - Resist developer and method for forming resist pattern using the same

Info

Publication number: WO2000057249A1
Application number: PCT/JP2000/001640
Authority: WO
Inventors: Kakuei Ozawa; Nobunori Abe
Original assignee: Nippon Zeon Co., Ltd.
Priority date: 1999-03-19
Filing date: 2000-03-17
Publication date: 2000-09-28
Also published as: JP2000267297A

Abstract

A resist developer containing an organic solvent having a boiling point of more than 180 °C under normal pressure for developing a resist material containing a copolymer of a styrene monomer and an acrylic monomer and used to form a resist pattern by an electron beam, and a method for forming a resist pattern by forming a latent image on a photosensitive film of such a resist material by applying an electron beam and performing development by a paddle method using such a developer. By using the resist developer, a resist pattern is formed on a substrate with suppressed pattern dimension error and good dimension stability even by even development by a paddle method.

Description

TECHNICAL FIELD The present invention relates to a resist developer and a method for forming a resist pattern using the same.

The present invention relates to a resist developer and a method for forming a resist pattern using the same. More specifically, the present invention relates to a resist developing solution capable of forming a resist pattern having good dimensional accuracy in which a pattern dimensional difference between an end portion and a central portion of a substrate is suppressed in forming a resist pattern by an electron beam, and The present invention relates to a method for efficiently developing a resist pattern by a paddle method and forming a resist pattern with good dimensional accuracy.

Background art

In manufacturing semiconductor devices, a resist is applied to the surface of a silicon wafer to form a photosensitive film, and a latent image is formed by irradiating light or ionizing radiation, and then developed to form a negative or positive image. An image is obtained by the lithography technique to be formed. Lithography equipment used in this technology is roughly classified into a mask pattern transfer method using light or X-rays, and a drawing method using beam scanning of electrons or ions. The latter drawing method is widely used in the manufacture of mask patterns and circuit patterns such as ASIC.

In addition, as a developing method, a method of immersing a substrate in a bath filled with a developing solution (dipping method), a method of spraying a developing solution onto a substrate (spraying method), and a method using a surface tension of the substrate are used. A method of placing a developer on the substrate surface (paddle method) is generally used. The dipping method and the spraying method are relatively insensitive to the temperature difference of the developer, and can perform stable development processing. However, in the dip method, since the developer is stored in a tank and used, the composition of a developer containing a low-boiling solvent changes little by little. Also, in the spray method, the development state changes depending on the spray conditions, so it takes time to study the conditions and the management of the conditions is strict. There is a title. On the other hand, in the paddle method, the amount of developing solution used can be kept to a minimum, and therefore, especially when processing large substrates or a large number of substrates, development using the paddle method, which has less impact on the environment, is advantageous. is there.

The paddle method is a method in which an amount sufficient to hold the substrate with its surface tension, that is, a small amount of a developing solution is applied to the substrate to perform development processing. Therefore, in this method, generally, the thickness of the developing solution layer held on the substrate by surface tension becomes thinner toward the edge of the substrate. For this reason, the degree of temperature change of the developing solution accompanying volatilization of the developing solution is large at the edge of the substrate and small at the center of the substrate. As a result, there is a problem that the developing characteristics are different between the central portion and the end portion of the substrate, resulting in a difference in pattern dimensions. The larger the size of the substrate and the finer the pattern, the larger the difference in pattern dimension.

By the way, as the radiation-sensitive positive resist material used in the drawing method, a polymer compound such as PMMA (polymethyl methacrylate) and poly-α-methylstyrene is generally used. Organic solvent is used as a developing solution.

As such a developer for resist materials, for example, a developer for a positive-type radiation resist material containing a copolymer having monomethylstyrene units and (meth) acrylate units has a boiling point of 7%. It has been proposed to use fatty acid esters at 0 to 180 ° C. (Japanese Patent Application Laid-Open No. 61-24949), but in this case, the boiling point is actually 150 ° C. It has only been confirmed that high-contrast development can be achieved using a developing solution at or below ° C.

In order to form a fine pattern, as a developer for a resist material containing an α-methylstyrene-based copolymer, a cyclic ether compound having a four-membered ring or more and six-membered ring or less which is a good solvent for the copolymer is used. It has been proposed to use a mixed solvent composed of a copolymer and a poor solvent (Japanese Patent Application Laid-Open No. Sho 61-22941). Also in this case, the boiling point of the cyclic ether compound is 150 ° C. or less. Disclosure of the birthplace

However, the present inventors have applied these developing solutions to the paddle developing process. However, it was not possible to solve the above-mentioned problem of the size of the pad. Under such circumstances, a first object of the present invention is to provide a resist pattern having good dimensional accuracy in which a pattern dimensional difference between an end portion and a central portion of a substrate is suppressed in forming a resist pattern using an electron beam. A second object is to provide a resist developer which can be formed, and to provide a method for forming a resist pattern with good dimensional accuracy by using the developer to efficiently develop by a paddle method. It is in.

The present inventors have conducted intensive studies to achieve the above object, and as a result, by using a developer containing a high boiling point organic solvent having a boiling point at normal pressure higher than a certain value as a developing solution, It has been found that the first object can be achieved, and that the second object can be achieved by performing development processing by a paddle method using the developer containing the high boiling point organic solvent. The present invention has been completed based on such findings.

That is, a first object of the present invention is to develop a resist material containing a copolymer of a styrene-based monomer and an acryl-based monomer in the formation of a resist pattern by an electron beam. This is attained by a resist developer, which comprises an organic solvent having a boiling point at normal pressure higher than 180 ° C. Further, a second object of the present invention is to form a latent image by irradiating an electron beam to a photosensitive film made of a resist material containing a copolymer of a styrene monomer and an acrylic monomer. Thereafter, in forming a resist pattern by development processing, the above-mentioned resist developing solution is subjected to development by a paddle method, and the above-mentioned resist developing solution is developed by a method of forming a resist pattern. BEST MODE FOR CARRYING OUT THE INVENTION

First, the resist developer of the present invention will be described.

The resist developer of the present invention is used for forming a resist pattern by an electron beam. As a resist material for forming the resist pattern, a copolymer of a styrene-based monomer and an acrylic monomer is used. Is used, this is an electron beam! It is suitable for pattern formation by H. The structural unit ratio (based on moles) of this copolymer is the structural unit derived from a styrene monomer and the structural unit derived from an acrylic monomer. The order is usually 80 Z 20 to 20 Z 80, preferably 75 25 to 25 Z 75, more preferably 70 Z 30 to 30 Z 70.

The styrene monomer is a monomer having a styrene structure, and specific examples thereof are styrene, 4-methylstyrene, 4-propylstyrene, 4-isopropylstyrene, 4-butylstyrene, 4-isobutylstyrene, and 3,4-dimethylstyrene. Styrene such as len, 4-ethyl-13-methylstyrene, 4-hydroxyquinstyrene, 4-hydroxy-13-methylstyrene, 4-methoxystyrene, its 4-substituted product, or its 3-, 4-substituted product Α-methylstyrene, 4-methyl-1-methylstyrene, 4-propyl-1-methylstyrene, 4-isopropyl-1-methylstyrene, 4-butyl-1-methylstyrene, 4-isobutyl-1-α-methylstyrene, 3,4-dimethyl-1-methylstyrene α-methylstyrene, 4-ethyl-3-methyl-1-α-methylstyrene, 4-hydroxy Monomethylstyrene such as 1-methylstyrene, 4-hydroxy-1-methyl-1-methylstyrene, 4-methoxy-1-α-methylstyrene, 4-substituted product thereof, or 3-, 4-substituted product thereof; α-chlorostyrene, 4- Methyl-chlorostyrene, 4-propyl-α-chlorostyrene, 4-isopropyl-1-α-chlorostyrene, 4-butyl-chlorostyrene, 4-isobutyl-chlorostyrene, 3,4-dimethyl-1-chlorostyrene Α-chlorostyrene, such as styrene, 4-ethyl-1-methyl-chlorostyrene, 4-hydroxy-chlorostyrene, 4-hydroxy-3-methyl-chlorostyrene, 4-methoxy-monochlorostyrene, etc. The 4-position substituted product, or the 3-, 4-substituted product thereof and the like can be mentioned.

These styrenic monomers may be used alone or in combination of two or more. However, α-methylstyrene compounds (α-methylstyrene, 4-substituted products thereof, Or its 3- or 4-substitution) is particularly preferred in that it gives a good pattern shape.

On the other hand, the acryl-based low molecular weight is an atalylic acid derivative, and specific examples thereof include methyl (meth) acrylate, ethyl (meth) acrylate, pill (meth) acrylate, and (meth) acrylic acid. Isopropyl acid, butyl (meth) acrylate, etc. (Meth) alkyl acrylate; (meth) acrylic acid such as phenyl (meth) acrylate, 4-methacrylic acid 4-chlorophenyl; benzyl (meth) acrylate, benzyl (meth) acrylate, 3,4-dimethyl (meth) acrylate Aralkyl (meth) acrylates such as benzyl; α-haloacryls such as methyl monochloroacrylate, ethylethyl monochloroacrylate, propyl monobromoacrylate, isopropyl α-chloroacrylate, and butyl monobromoacrylate Alkyl acrylates; Aryl monohaloacrylates such as phenyl monochloroacrylate; benzyl aralkyls such as benzyl <2-bromoacrylate and 3,4-dimethylbenzyl α-chloroacrylate; monocyanoacrylic Methyl acrylate, α-ethyl acrylate, a-methyl acrylate Pill, α-alkyl acrylates such as isopropyl α-cyanoacrylate and butyl cyanoacrylate; α-aryl acrylates such as phenyl acrylate; benzyl α-cyanoacrylate and 3,4-dimethylbenzyl mono-cyanoacrylate α-cyanoacrylic acid aralkyl; unsubstituted or substituted acrylonitrile-based compounds such as acrylonitrile, methacrylonitrile, polyacrylonitrile, and bromoacrylonitrile; (meth) acrylamide, 、 -methyl (meth) acrylamide Unsubstituted or Ν-substituted (meth) acrylamides such as ド, Ν, Ν-dimethyl (meth) acrylamide, Ν-phenyl (meth) acrylamide; α-chloroacrylamide, Hi-bromoacryl Amid Unsubstituted or Ν-substituted “-haloacrylamides such as -methyl-a-chloroacrylamide, N, N-dimethyl-α-chloroacrylamide, Ν-phenyl-α-chloroacrylamide, etc. And the like.

These acryl-based monomers may be used alone or in combination of two or more. Among them, the haloacrylate ester-based compounds (na-halo) are preferred because of their high sensitivity. Alkyl acrylate, aryl aryl haloacrylate, aralkyl α-haloacrylate; particularly preferred is alkyl α-haloacrylate).

The copolymer is prepared by charging each of the above monomers so as to be a polymer in the ratio of each of the structural units described above, and polymerizing the monomers by solution polymerization, bulk polymerization, suspension polymerization, emulsion polymerization, or the like. And obtained by

The weight average molecular weight of the copolymer is not particularly limited, but the weight average molecular weight in terms of polystyrene (hereinafter sometimes referred to as Mw) calculated by gel permeation chromatography (GPC) using tetrahydrofuran is 50, Preferred are those with a force of 0,000, 1,000,000.

Generally, the resist material is a solution obtained by dissolving the above copolymer in an organic solvent such as methyl phenyl ether, diethylene glycol dimethyl ether, or o-dichlorobenzene. It can contain various additives commonly used in resist materials for forming a resist pattern, such as a surfactant.

The method for preparing the resist material is not particularly limited. For example, the above-mentioned copolymer of a styrene-based monomer and an acrylic-based monomer, and various additives used as needed, are added to the above-mentioned appropriate organic solvent. The desired resist material can be prepared by dissolving and then, if necessary, filtering by using a membrane filter or the like.

The resist developer of the present invention contains an organic solvent having a boiling point at normal pressure higher than 180 ° C, but has a boiling point at normal pressure in the range of 185-250 ° C. Those containing an organic solvent having a melting point of 30 ° C. or lower are preferred. Further, the developer may contain L as one kind of the organic solvent, or L as two or more kinds.

A developer containing two or more kinds of organic solvents is preferable because the ratio of the remaining film and the resolution can be well balanced.

When two or more kinds of organic solvents are used, a combination having a boiling point difference of 100 ° C. or less, preferably 80 ° C. or less is particularly preferable because there is no change in pattern dimension.

The developing solution of the present invention is used as a liquid at a temperature in a developing process. Therefore, even if a certain substance alone is solid at the development processing temperature, it can be used as a developer as long as it becomes liquid at the development processing temperature when mixed with another organic solvent. Examples of the organic solvent having a boiling point at normal pressure higher than 180 ° C. include the following. The number in parentheses after the compound name is the boiling point at normal pressure (in units). Where the decimal places are rounded or truncated values. If the boiling point has a range, the upper limit is described.

(a) Hydrocarbons: n-dodecane (216), tetralin (207), n-butylbenzene (183), cyclohexylbenzene (240), o-getylbenzene (183), m-getylbenzene (181) ), P-Jetylbenzene (183), n-pentylbenzene (205), dipentylbenzene (280), dodecylbenzene (331), bicyclohexyl (238), decalin (195), diisopropenylbenzene (231 ) , Such

(b) Halogenated hydrocarbons: 1,2,4-trichlorobenzene benzene (210), 1-chloronaphthalene (259), 0-bromobenzene (224), 1-bromonaphthalene (281), 1-chloro Mouth octane (182), black mouth decane (223), etc. (c) Alcohols: 2-ethyl-1-1 hexanol (184), 1-nonano-mono (214), 3,5,5-trimethyl-1-1 hexanol (194), 1-decanol (231), 1-ndeneol (243), 1-dodecanol (259), 1,2-ethanediol (197), 1,2-propanediol (188), 1,3-propanediol (214), 1,2- Butanediol (190), 1,3-butanediol (207), 1,4-butanediol (229), 1,5-pentanediol (242), 2-butene1-1,4-diol (238), 2-Methyl-2,4-pentanediol (197), 2-ethyl-1,3-hexanediol (243), 2- (isopentyloxy) ethanol (181), 2_ (hexyloxy) ethanol (208) ), 2-Phenoxyethanol (244), 21- (benzyloxy) ethanol (256), diethylene glycol (244), diethylene glycol monomethyl ether (194), diethylene glycol monoethyl ether (202), diethylene glycol monobutyl ether (230), triethylene glycol (288), triethylene glycol monomethyl ether (249), tetra Ethylene glycol (327), dipropylene glycol monomethyl ether (190), dipropylene glycol monoethyl ether (197), tripropylene glycol monomethyl ether (243), 3 1,2-propanediol (213), 3-hydroxypropiononitrile (220), 2,2'-thiodiethanol (282), 1-octanol (195), benzyl alcohol (205), Glycerin (290), etilse mouth solu-acetate (192), etc.

(d) Ketones: acetonylacetone (191), holon (197), acetofenone (202), isophorone (215), and the like.

(e) Ethers: dihexyl ether (226), butyl phenyl ether (210), n-pentyl phenyl ether (214), isopentyl phenyl ether (225), benzyl ethyl ether (189) , Diphenyl ether (258), dibenzyl ether (298), veratrol (206), 1,2-dibutoxetane (203), diethylene glycol getyl ether (18

8), diethylene glycol dibutyl ether (254), triethylene glycol dimethyl ether (222), n-amyl ether (188) and the like.

(f) Esters: 2-ethylhexyl acetate (198), benzyl acetate (213), isopentyl butyrate (184), isopentyl isovalerate (194), methyl benzoate (199), ethyl benzoate (213) ), Propyl benzoate (231), butyl benzoate (250), isopentyl benzoate (262), benzyl benzoate (324), ethyl ethyl cinnamate (271), a-peptirolactone (20

4), Jethyl oxalate (185), Dibutyl oxalate (245), Diethyl malonate (198), Dimethyl maleate (200), Getyl maleate (22

5), dibutyl maleate (280), dibutyl sebacate (345), dimethyl phthalate (282), getyl phthalate (295), dibutyl phthalate (33

9), bis (2-ethylhexyl) phthalate (386), ethylene glycol monoacetate (182), ethylene diacetate (190), ethylene glycol butyrate monoester (220), ethylene glycol propionate diester (210) , Monoacetin (182), propylene carbonate (242), butyl lactate (185), methyl salicylate (223), 2-butoxyshethyl acetate (191), 2-phenyloxyshethyl acetate (259), diethylene glycol mono Etilue Teracetate (217), diethylene glycol monobutyl ester teracetate (246), methyl cyanoacetate (205), ethyl cyanoacetate (206), r-valerolactone (207), and monoprolactone (216).

(g) Amines: aniline (184), N-methylaniline (196), N, N-dimethylaniline (193), N, N-getylaniline (217), o-toluidine (200), m-toluidine ( 204), p-toluidine (201), quinoline (237), diethylenetriamine (207), tetraethylenepentamine (333), o-chloroaniline (208), etc.

(h) Amides: formamide (210), N-methylformamide (185), N-methylpyrrolidone (202), N, N-dimethylacetamide (194), hexamethylphosphate triamide ( 233), / 3—ptyrolactam (245), δ-valerolactam (256), etc.

(i) Fatty acids: valeric acid (185), cabronic acid (205), 2-ethylbutyric acid (190), caprylic acid (239), 2-ethylhexanoic acid (227), oleic acid (360), etc. .

(j) Phenols: m-cresol (202) and the like.

(k) Sulfoxide * Sulfones: dimethyl sulfoxide (189), sulfolane (287) and the like.

(1) Nitrile group-containing compounds: benzonitrile (191), α-tolunitrinole (233), lactonitrile (184), ethylene cyanohydrin (220), adiponitrile (295) and the like.

(m) Nitro group-containing compounds: nitrobenzene (210), 0-nitroanisole (277) and the like.

Among the above compounds, esters, amides, sulfoxidesulfones are preferred, and particularly esters having a boiling point at normal pressure of 185 ° C to 250 ° C and a melting point of 30 ° C or less, Amides and sulfoxide'sulfones are preferred. A developer containing at least one selected from cyclic esters, cyclic amides and sulfoxides in an amount of 30% by weight or more, preferably 40% by weight or more, more preferably 50% by weight or more, It is particularly preferable because high sensitivity can be obtained.

If desired, an organic solvent having a boiling point at normal pressure of 180 ° C. or lower can be mixed with the developer of the present invention as long as the effects of the present invention are not impaired. The amount may be 25% by weight or less, preferably 20% by weight or less, more preferably 15% by weight or less based on the whole developer. Even if an organic solvent having a boiling point at normal pressure of 180 ° C or lower is mixed with a solvent having a boiling point at normal pressure of 150 ° C or higher, the effect of the present invention is hardly impaired. Absent.

The method for developing the above-mentioned resist material using the developing solution of the present invention is not particularly limited. However, as described in the method for forming a resist pattern of the present invention described below, if the development processing is performed by a paddle method, , To maximize its effect.

Next, a method for forming a resist pattern according to the present invention will be described.

In the method for forming a resist pattern according to the present invention, first, a resist material containing a copolymer of the styrene-based monomer and the acryl-based monomer is applied on a substrate such as a silicon wafer by a spinner or the like. Then, it is dried to form a photosensitive film. Next, after irradiating the photosensitive film with an electron beam to form a latent image, the substrate is usually rotated at a speed of 100 to 500 rotations per minute, usually at a temperature of 10 to 30 ° C., preferably 1 to 30 ° C. The developer of the present invention at 5 to 25 ° C. is dripped until spread on the substrate (usually 0.5 to 30 seconds, preferably 1 to 15 seconds), and the surface tension is applied to the substrate. And load the developer. Next, the rotation of the substrate is stopped, or the rotation is reduced to a low speed of 50 rotations per minute or less, usually for 0.5 to 30 minutes, preferably for 1 to 15 minutes, about 10 to 30 ° C, The development is preferably carried out at a temperature in the range of 15 to 25 ° C.

Then, if necessary, the remaining developer and the like are removed by a rinsing solution. Examples of the organic solvent used as the rinse liquid include toluene, xylene, ethyl acetate, butyl acetate, isopropyl alcohol, methyl isobutyl ketone, and 2-heptanone. These solvents are used alone or in combination of two or more. The rinsing liquid preferably has a boiling point at normal pressure of 150 ° C. or lower, more preferably 120 ° C. or lower.

In addition, the developing step and the rinsing step are alternately repeated about 2 to 10 times. Can also be.

In this manner, a resist pattern with good dimensional accuracy in which the pattern dimensional difference between the substrate end and the central part is suppressed is formed. Example

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Examples 1-3, Comparative Examples 1, 2

Structural unit derived from monomethylstyrene Z Prepare a resist material consisting of a copolymer (Mw = 331,000) with a structural unit derived from methyl monochloroacrylate of 50Z50 on a molar basis and an organic solvent. The solution was filtered through a high density polyethylene (UPE) membrane filter to prepare a resist solution.

After spin coating the above resist solution on 6 inch blanks coated with 0.08 zm thick chromium, bake it on a hot plate at 180 ° C for 180 seconds to form a 0.5 mm thick resist film. Formed.

Next, the electron beam irradiator J BX-700 OMV [manufactured by JEOL Ltd.] was used to adjust the amount of electron beam irradiation on the resist film formed on the blanks at an accelerating voltage of 20 kV to form a 132 mm square Draw a 1.0 m line & space pattern. After pattern drawing, a developer having the composition shown in Table 1 was dropped on the substrate for 3 seconds at 23 ° C while rotating the substrate at a speed of 120 rotations per minute, so that the developer spread over the entire substrate surface. . The rotation was stopped at the same time as the supply of the developing solution was stopped, and while maintaining the temperature, the developing solution was left for 180 seconds in a state where the developing solution was held at a surface tension on the substrate to perform development. After development, methyl isobutyl ketone (boiling point 118 ° C) was dropped as a rinsing liquid for 20 seconds while rotating the substrate at 300 rpm to rinse the substrate. Finally, the rinse liquid was dried and removed by a nitrogen stream to obtain a positive resist pattern.

After the formation of the resist pattern, the pattern dimensions were measured using an electronic scanning microscope, and the difference between the maximum value and the minimum value was determined. The value obtained by dividing this difference by the pattern dimension (pattern dimension difference rate) was used as an index of pattern dimension variation. Results obtained using each developer Are shown in Table 1.

Pattern dimension difference rate (%)

= (Maximum value of pattern size-Minimum value of pattern size) Z (Pattern size) X100 The results obtained using each developer are shown in Table 1. Table 1

As can be seen from Table 1, the resist pattern formed by developing with the developing solution of the present invention has a smaller pattern and deviation than the resist pattern formed by developing with the developing solution of the comparative example. The dimensional difference ratio is small. Industrial applicability

In the resist developer of the present invention, the components are hardly volatilized and the composition change is small. Therefore, if the developing solution of the present invention is used, the developing treatment by the paddle method can be performed on the substrate. It is possible to obtain a resist pattern having good dimensional stability, in which a pattern dimensional difference is suppressed. Also, with this developer, the composition of the developer is stable for a long period of time even when the developer is stored in a tank as in the dip method, so that it is expected that a good resist pattern can be continuously obtained.

Claims

The scope of the claims

1. A resist developer for developing a resist material containing a copolymer of a styrene-based monomer and an acryl-based monomer in the formation of a resist pattern using an electron beam. A resist developer comprising an organic solvent having a boiling point higher than 180 ° C.

2. The resist developer according to claim 1, wherein the styrene-based monomer forming the copolymer in the resist material is a monomethylstyrene-based compound, and the acryl-based monomer is a haloacrylate ester-based compound.

3. The copolymer according to claim 1, wherein the ratio of the structural unit derived from the styrene monomer to the structural unit derived from the noacrylic monomer in the copolymer is 80/20 to 20Z80 on a molar basis. Resist developer.

4. Claim that the copolymer has a weight average molecular weight in terms of polystyrene of 50,000, 000, -1, 000, 000, calculated by gel 'permeation' chromatography (GPC). Item 4. The resist developer according to Item 1.

5. The resist developer according to claim 1, wherein the organic solvent has a boiling point at normal pressure in the range of 185 to 250 ° C and a melting point of 30 ° C or less.

6. The resist developer according to claim 1, wherein the organic solvent is at least one selected from esters, amides, and sulfoxides' sulfones.

7. The resist developer according to claim 6, wherein the organic solvent contains at least 30% by weight or more selected from cyclic esters, cyclic amides, and sulfoxides.

8. A latent image is formed by irradiating an electron beam to a photosensitive film made of a resist material containing a copolymer of a styrene-based monomer and an acryl-based monomer, and then developed to form a resist pattern. 3. A method for forming a resist pattern, wherein the resist pattern is formed by a paddle method using the resist developer according to claim 1.

9. The styrene monomer forming the copolymer in the resist material is an α-methylstyrene compound, and the acryl monomer is a haloacrylate compound. 9. The method for forming a resist pattern according to claim 8, wherein

10. The structural unit derived from a styrene-based monomer in the copolymer, wherein the ratio of structural units derived from a Z-acrylic monomer is from 80 to 20Z80 on a molar basis. Method of forming resist pattern.

1 1. Claim that the copolymer has a weight average molecular weight in terms of polystyrene of 50,000 to 1,000,000,000, as calculated by gel permeation chromatography (GPC). Item 10. The method for forming a resist pattern according to Item 8.

12. The resist according to claim 8, wherein the organic solvent in the developer has a boiling point at normal pressure in the range of 180 to 250 ° C and a melting point of 30 ° C or less. Method of pattern formation.

13. The method of forming a resist pattern according to claim 8, wherein the organic solvent in the developer is at least one selected from esters, amides, and sulfoxides / sulfones.

14. The resist pattern according to claim 13, wherein the organic solvent in the developer contains at least 30% by weight or more selected from cyclic esters, cyclic amides, and sulfoxides. Forming method.

15. The method for forming a resist pattern according to claim 8, wherein the developing treatment by the paddle method is performed at a temperature of 10 to 30 ° C.

1 6. The method for forming a resist pattern according to claim 8, wherein a rinsing process is performed after the developing process by the paddle method.

17. The method for forming a resist pattern according to claim 16, wherein the rinsing treatment is performed using a rinsing liquid composed of an organic solvent having a boiling point of 150 ° C. or less at normal pressure.