JPS63234006A - Halogen-containing polyacrylic ester derivative - Google Patents

Abstract

PURPOSE:To provide the titled novel ester derivative containing halogen and benzene ring, easy to cause main chain degradation reaction by electron beam or X-ray irradiation, useful as a resist material improved in dry-etching resistance. CONSTITUTION:The objective novel ester derivative of formula I [A is constituent derived from a monomer having copolymerizable double bond; R is group of formula II or III (R1 and R2 are each H or fluorine-substituted methyl; but not H simultaneously; R3 is H or lower alkyl); X is halogen or CH3; m is positive integer; n is 0 or positive integer, n/m being 0-2]. This ester derivative can be prepared by polymerization, e.g., of the corresponding acrylic ester monomer (e.g., alpha-chloroacrylic acid 1-phenyl-2,2,2-trifluoroethyl ester).

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a halogen-containing polyacrylic ester derivative, and more specifically, to a polyacrylic ester derivative containing a halogen and a benzene ring, and the halogen-containing polyacrylic ester derivative. The present invention relates to a method for forming a resist pattern using an acrylic acid ester derivative as a resist material, and the resist material.

[Prior Art] Polymethyl methacrylate (hereinafter abbreviated as PMMA) is well known as an electron beam positive resist. PMM
Although A has high resolution, it has low sensitivity and poor dry etching resistance. In addition, for the purpose of increasing sensitivity, (
Polymers of esters of meth)acrylic acid or its derivatives with mono- or polyfluoroalkanols are used as positive resists for pattern formation by electron beams (Japanese Unexamined Patent Publication No. 55-1°8638, 1986-
Similar to PMMA, dry etching resistance is insufficient. Although polyphenyl methacrylate has improved dry etching resistance compared to PMMA, its sensitivity is as low as that of PMMA.

[Problems to be solved by the invention] In recent years, various polymers containing halogens such as fluorine have been studied and used for various purposes by taking advantage of their properties. Due to its high sensitivity, it is attracting attention as a resist material. however,
Although the recent trend toward miniaturization has shifted to dry processes, it still has the drawback of insufficient dry etching resistance as a resist material.

The present invention has been made from the above-mentioned viewpoint, and its object is to obtain a polymer which can be used as a resist material, particularly having improved dry etching resistance.

[Means for Solving the Problems] Based on this background, the present inventors have conducted extensive research and have completed the present invention.

That is, the present invention is based on the following general formula (where A represents a structural unit derived from a monomer having a copolymerizable double bond, R represents hydrogen, and R1 and R2 represent hydrogen or a fluorine-substituted methyl group). , cannot become hydrogen at the same time.

R3 represents hydrogen or a lower alkyl group. X represents a halogen atom or a methyl group. m represents a positive integer, and n represents O or a positive integer. n/m is 0-2 - preferably 0-1
It is. The present invention provides a halogen-containing polyacrylic acid ester derivative represented by the following formula, and further provides a method for forming a resist pattern using this derivative as a resist material, and the resist material.

The halogen-containing polyacrylic ester derivative of the present invention is an α-substituted acrylic ester polymer containing a halogen or methyl group at the α-position, a fluorine atom, and a benzene ring at the ester moiety.

The halogen-containing polyacrylic ester derivative of the present invention can be obtained by polymerizing the corresponding acrylic ester monomer. As α-position halogen, fluorine,
Chlorine is preferred. Furthermore, examples of substituents on the benzene ring include hydrogen, fluorine, and lower alkyl groups. The lower alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, for example,
Methyl group.

Ethyl group, etc.

Examples of α-halogenoacrylic acid ester monomers include:
α-Chloroacrylic acid 1-phenyl-2゜2.2-)lifluoroethyl ester, α-chloroacrylic acid 2-phenyl-hexafluoroisopropyl ester, α-chloroacrylic acid pentafluorophenyl ester, α-
Fluoroacrylic acid 1-phenyl-2,2,2-trifluoroethyl ester, α-fluoroacrylic acid 2-phenyl-hexafluoroisopropyl ester.

Examples include α-fluoroacrylic acid pentafluorophenyl ester. This α-halogenoacrylic acid ester monomer can be produced, for example, by the following method.

In the case of α-chloroacrylic acid ester monomers, the acrylic acid ester is synthesized by the reaction of acrylic acid loride with an alcohol or its alkali salt corresponding to the ester to be prepared, and then chlorine gas React with α,
The desired α-chloroacrylic acid ester monomer is synthesized by converting it into β-dichloropropionic acid ester, adding the same mole of quinoline or pyridine, and performing vacuum distillation or reflux, followed by filtration, extraction, and column separation. be able to.

The α-fluoroacrylic acid ester monomer is, for example, described in US Pat. No. 3.262.968 or Colect
ion of Czeehoslovak Ch.
emlcalCommunications, 29
．． 234 (1964), etc., it can be synthesized by reacting fluorooxaloester with formalin.

The polymer of the present invention can be produced by a known method such as bulk polymerization, solution polymerization, emulsion polymerization, etc. from α-halogenoacrylate monomer, and the degree of polymerization is 20 to 2000.
It is 0. As the polymerization initiator, hydrogen peroxide, peroxides such as benzoyl peroxide, azo compounds such as azobisisobutyronitrile, persulfates such as potassium persulfate, etc. can be used.

The polymers of the invention can also be produced by copolymerization with radically copolymerizable monomers.

Examples of such monomers include acrylic esters such as methyl acrylate, ethyl acrylate, and butyl acrylate; methacrylic esters such as methyl methacrylate, 2-hydroxyethyl methacrylate, and glycidyl methacrylate; -Methyl chloroacrylate 0. α-substituted acrylic esters such as methyl α-trifluoromethyl acrylate, ethyl α-cyanoacrylate, and acrylic acid.

Unsaturated carboxylic acids such as methacrylic acid and itaconic acid, acid amides such as acrylamide, methacrylamide and N-phenylmethacrylamide, vinyl esters such as vinyl acetate and vinyl propionate, aromatics such as styrene and α-methylstyrene. Examples include vinyls, acrylonitrile, methacrylonitrile, and the like.

[Function] The halogen-containing polyacrylic acid ester derivative of the present invention can be used as a resist material to form a resist pattern by electron beam drawing or the like.

For this purpose, among the halogen-containing polyacrylic acid ester derivatives of the present invention, those having a chlorine atom at the α-position are particularly excellent in electron beam sensitivity and dry etching resistance.

There are no particular limitations on how to use the halogen-containing polyacrylic acid ester derivative of the present invention to form a resist pattern by electron beam drawing or the like, and any conventional method can be used.

When using the halogen-containing polyacrylic acid ester derivative of the present invention as a resist material, the coating solvent is not particularly limited as long as it can dissolve the polymer and form a uniform film, such as xylene, toluene, benzene, etc. The amount used is a conventional amount, for example, about 5 to about 30% of the halogen-containing polyacrylic ester of the present invention, 95% of the solvent. or about 70%
That's about it.

As the developer, for example, a mixed solvent of the above-mentioned solvents and alcohol, or a mixed solvent of ester or ketone solvent and alcohol can be used. Other methods such as coating, blebake, tB light, and development can be carried out according to conventional methods.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto.

In addition, the electron beam sensitivity test in Examples was conducted by the following method.

A xylene or ethylene glycol monoethyl ether acetate solution of the polymer was spin-coded onto a silicon wafer to obtain a 0.6 μm coating. 30 at 150℃
After prebaking for a minute, desired portions of the coating film were irradiated with an electron beam at an accelerating voltage of 20 KV at various doses. Next, development was performed by dipping at 24° C. to selectively remove the irradiated areas. Sensitivity and resolution were evaluated from a sensitivity curve diagram depicting the relationship between dose and residual film thickness after development.

Here, the sensitivity (hereinafter referred to as S value) is indicated by the value of the irradiation amount at which the residual film thickness becomes zero. In addition, the resolution (hereinafter γ
The value is indicated by a pair of points on the tangent line corresponding to the S value of the sensitivity curve at which the film thickness begins to decrease, and the larger the value, the higher the resolution.

[For details, refer to "Cutting Edge Applied Technology of Fluorine Compounds," CMC, published April 24, 1980, pages 139-140.] The dry etching resistance test was performed using dry etching equipment D.
Resistance to reactive sputtering by CF4 gas was observed using EM-451 model (manufactured by Nikkei Anelva Co., Ltd.).

Example 1 (Synthesis of 1-phenyl-2,2゜2-trifluoroethyl α-chloroacrylate) 33 g of 1-phenyl-2,2,2-)rifluoroethanol was added to 157 g of 1 wt% aqueous sodium hydroxide solution.
(0,188 mol), cooled the solution on ice, and added 20.4 g (0,226 a+
ol) was added dropwise over 1 hour. The resulting oil phase was separated by ethyl ether extraction. Next, the ethyl ether solution was washed with water and saturated brine, and further dehydrated with sodium sulfate. Ethyl ether was removed by evaporation using an evaporator, and the remaining oil was distilled under reduced pressure (60℃/2
smlg) Shita.

The reaction product was 37.6sr.

Next, the above reaction product 3 was added to 14 300m flasks.
0.0 g and 1.00 r of chloroform were added and cooled on ice. While stirring, chlorine gas was blown into the system at a flow rate of 10 ml/s+In for 5 hours. Thereafter, chloroform was removed by evaporation using an evaporator, and the remaining oil was distilled under reduced pressure (91'''C/2+ul1g).

The reaction product was 24.0sr.

Next, 5.3 g of pyridine was added to 20.0 g of the above reaction product.
was added and stirred at 50°C for 2 hours.

After removing the precipitate by filtration, it was made into an ethyl ether solution. Next, the ethyl ether solution was washed with water and saturated brine, and further dehydrated with sodium sulfate. Ethyl ether was removed by evaporation using an evaporator, and the remaining oil was distilled under reduced pressure (73°C/11 g). 12.5 g of 1-phenyl-2,2,2-trifluoroethyl L,α-chloroacrylate was Obtained.

(Polyα-chloroacrylic acid 1-phenyl-2゜2.2
-Synthesis of trifluoroethyl) α-chloroacrylic acid 1-phenyl-2,2°2-t°
Lifluoroethyl 3. 0.37 ml of a benzene solution of Og, azobisisobutyronitrile (containing 0.1 wt% of azobisisobutyronitrile) and 3.9 ml of benzene were placed in a flask and vacuum degassed according to a conventional method. After stirring the flask at 70° C. for 7 hours, the reaction product was poured into petroleum ether to precipitate the polymer, which was filtered and dried to obtain 1.75 r of white precipitate.

It was confirmed by elemental analysis, IR, and 13c-NMR that the obtained polymer was the desired poly-alpha-chloroacrylic acid 1-phenyl-2,2,2-trifluoroethyl.

■) Elemental analysis C (%) H (%) F (%) Cu2 (%) Analysis value 49.7 3.1 22.0 13.4 Theoretical value 4
9.9 3.0 21.6 13.42) Infrared absorption spectrum (KBr method) 1750cm (C-0 stretching vibration) 1500CIl
-1 (C-C ring stretching vibration) 1460an-1 Disappearance of 1620 cm-' (C-C stretching vibration) The infrared absorption spectrum of the obtained polymer is shown in FIG. In addition, the infrared absorption spectrum of the monomer is also shown for comparison.

3) C-NMR (solvent CDCjl, internal standard C
DCl2) Cj ■ 86.0
pp-■ ■ ■ 54.7.52.3pp■
-CM 2-C-■ IB7.9. 167.4pp
Otori ■ 1 ■
75.3ppmc-o ■ 122
．． 9ppm1 ■ 130.3pp
mO■, ■12g, 9. 128.7ppm■1 ■
(1) 129.4pp (129.4pp) (H-C-CF3) The 'C-NMR spectrum of the obtained polymer is shown in FIG.

In addition, the weight average component weight of the polymer obtained in this example is
As a result of GPC measurement, it is 1.4X10B in terms of polystyrene.
Met.

(Electron Beam Sensitivity Test) Next, an electron beam sensitivity test was conducted, and when diisopropyl ketone/isopropyl alcohol was used as the developer, the S value and γ value were 6 μC/cj, 2.
0, and when diisobutyl ketone/isopropyl alcohol is used, the S value and γ value are respectively 20 μC/
A positive type pattern with cj of 6.6 was formed.

(Dry etching resistance test) Polyα-chloroacrylic acid 1-phenyl-2゜2.2-
A dry etching resistance test against reactive sputtering of trifluoroethyl ester using CF4 gas was conducted, and the etching rate was 1700 A/m1n. For comparison, a similar test was conducted on polymethyl methacrylate, and the etching rate was 2.
It was 200 people/sin.

Example 2 α-chloroacrylic acid 2-phenylhexafluoroisopropyl ester was polymerized in the same manner as in Example 1,
Polyα-chloroacrylic acid 2-phenylhexafluoroisopropyl ester was obtained. Weight average molecular weight is G
As a result of PC measurement, it was 1.2×106 in terms of polystyrene.

Next, an electron beam sensitivity test was conducted, and when diisopropyl ketone/isopropyl alcohol was used as the developer, the S value and γ value were 5 μC/cj and 2.0, respectively.
A positive type pattern was formed.

Further, when a dry etching resistance test against reactive sputtering using CF4 gas was conducted, the etching rate was 1800 people/1n.

Example 3 (Synthesis of α-chloroacrylic acid pentafluorophenyl ester) 45% of pentafluorophenol was added to 200t of a 10wt% aqueous sodium hydroxide solution. After dissolving Og (0,245 mol), the solution was cooled with water, and 26.5 g (0,293 mol) of acrylic acid chloride was added dropwise thereto over 1 hour, followed by stirring for 15 hours. The resulting oil phase was separated by ethyl ether extraction. Next, the ethyl ether solution was washed with water and saturated brine, and further dehydrated with sodium sulfate. Ethyl ether was removed by evaporation using an evaporator, and the remaining oil was distilled under reduced pressure. The reaction product was 42.8g.

Next, 4 o, or of the above reaction product and 100 g of chloroform were added to 14 300 m LOPRA and SC, and the mixture was cooled with water. While stirring, chlorine gas was blown into the system at a flow rate of 50 ml/win for 6 hours. Thereafter, chloroform was removed by evaporation using an evaporator, and the remaining oil was distilled under reduced pressure. The reaction product was 41.9 g.

Next, the above reaction product 4ff, Or to pyridine 9.2
g and stirred at 50°C for 2 hours.

After removing the precipitate by filtration, an ethyl nitrite solution was prepared. Next, the ethyl ether solution was washed with water and saturated brine, and further dehydrated with sodium sulfate. Ethyl ether was removed by evaporation using an evaporator, and the remaining oil was distilled under reduced pressure to obtain 21.2 g of α-chloroacrylic acid pentafluorophenyl ester.

(Synthesis of polyα-chloroacrylic acid pentafluorophenyl ester) 3.0 g of α-chloroacrylic acid pentafluorophenyl ester, 0.9 ml of benzene solution of azobisisobutyronitrile (0.1vt of azobisisobutyronitrile)
%) and 2.5 ml of benzene were placed in a flask and vacuum degassed according to a conventional method.

After stirring the flask at 70° C. for 9 hours, the reaction product was poured into petroleum ether to precipitate a polymer, which was filtered and dried to obtain 1.6 g of a white precipitate.

It was confirmed by elemental analysis, IR and 'C-NMR that the obtained polymer was the desired polyα-chloroacrylic acid pentafluorophenyl ester.

l) Elemental analysis C (%) H (%) FC%')CflC%) Analysis value 39.7 0.9B 34.4 12.8
Theoretical value 39.6 0.73 34.9 18.
02) Infrared absorption spectrum - (KBr method) 1790 (J
-' (C-0 expansion/contraction m movement) 1550CIl (C
-C ring stretching vibration) Disappearance of 1620 cm-' (C-C stretching vibration) The infrared absorption spectrum is shown in FIG. For comparison, α-chloroacrylic acid pentafluorophenyl ester is shown.

3) C-NMR (solvent CDCl, internal standard CD
Cl2) C, Il @ 68.8ppm
1 0 48-52 ppm [F]
■ -CH2-C-■ tse, tppat■1
■ 124.6ppmC-O■
141.191)Ill
■ 13g, 1ppsO■ 128
．． 9. 140.2p1) a+ The C-NMR spectrum is shown in FIG.

In addition, the weight average molecular weight of the polymer is as a result of GPC measurement,
9. in terms of polystyrene. It was lXIO3.

(Electron beam sensitivity test) - Next, an electron beam sensitivity test was conducted, and when methyl isobutyl ketone/isopropanol was used as the developer, the S value and γ value were 15 μC/cj and 2.0, respectively. A positive type pattern was formed.

(Dry Etching Resistance Test) A dry etching resistance test of polyα-chloroacrylic acid pentafluorophenyl ester against reactive sputtering using CF 4 gas was conducted, and the etching rate was 1650 people/1n.

Example 4 Similar to the synthesis method of Example 3, methacrylic acid pentafluorophenyl ester monomer was synthesized by reaction of methacrylic acid chloride and pentafluorophenol, and polymerization was performed using azobisisobutyronitrile as an initiator. , polymethacrylic acid pentafluorophenyl ester was obtained.

It was confirmed by elemental analysis, IR and 13C-NMR that the obtained polymer was the desired polymethacrylic acid pentafluorophenyl ester.

1) Elemental analysis C (%) H (%) F (%) Analysis value 47.5 2,1 37.3 Theoretical value 47.
6 2,0 37.72) Infrared absorption spectrum (K
Br method) 1780aa (C-0 stretching vibration) 1520all
(C-C ring stretching vibration) The infrared absorption spectrum is shown in FIG.

8) C-NMR (solvent CDC1, internal standard CDCl3) ■CH3■ 4[f, 4ppm I o52, 7 p p I11■
■ CH2C-■ 19. lppm1■ ■
172.8-173.0ppmC-O■ 124
．． 9ppm! ■ 141.2ppmO■
lH, lppm ■F Note that the C-NMR spectrum is shown in FIG.

In addition, the weight average molecular weight of the polymer is as a result of GPC measurement,
9. in terms of polystyrene. ? It was X105.

Next, an electron beam sensitivity test was conducted, and when methyl isobutyl ketone/isopropanol was used as the developer, a positive type pattern was formed with an S value and a γ value of 25 μC/cJ and 2.2, respectively. Ta.

Example 5 1.26 g of a-chloroacrylic acid 1-phenyl-2,2゜2-trifluoroethyl ester, 0.74 g of methacrylonitrile, and 0.52 ml of a benzene solution of azobisisobutyronitrile (azobisisobutyronitrile) Lonitrile 0.
(containing 1vt%) and 1.75 ml of benzene were placed in a flask and vacuum degassed according to a conventional method. The flask was heated to 70°C.
After stirring for 20 hours, the reaction product was poured into methanol to precipitate the polymer, filtered and dried to obtain α-chloroacrylic acid 1-phenyl-2,2,2-)lifluoroethyl ester/ A methacriconitrile copolymer was obtained. As a result of elemental analysis, the copolymerization ratio was found to be 50,150 in terms of molar ratio. In addition, the weight average molecular weight is the result of GPC measurement,
It was 4°0XIO5 in terms of polystyrene.

Next, an electron beam sensitivity test was conducted, and it was found that when developing for 1 minute using methyl isobutyl ketone/isopropyl alcohol as the developer, the S value and γ value were each 10.
A positive type pattern with μC/cJ of 3.1 was formed.

Further, when a dry etching resistance test against reactive sputtering using CF4 gas was conducted, the etching rate was 1500 people/1n.

Example 6 2.58 g of α-chloroacrylic acid 1-phenyl-2,2゜2-trifluoroethyl ester, 0.42 g of methyl methacrylate, 0.46 ml of a benzene solution of azobisisobutyronitrile (azobisisobutyronitrile 0
．． (containing 1vt%) and 2.9 ml of benzene were placed in a flask, and according to Example 5, a polymer was obtained. As a result of elemental analysis, the copolymerization ratio was 76/24 in terms of molar ratio. Moreover, the weight average molecular weight was 1.4×10B in terms of polystyrene as a result of GPC measurement.

Next, an electron beam sensitivity test was performed, and when development was performed for 1 minute using diisopropyl ketone/isopropyl alcohol as the developer, the S value and γ value were each 20μ.
A positive type pattern with C/cJ of 5.5 was formed.

Further, when a dry etching resistance test against reactive sputtering using CF4 gas was conducted, the etching rate was 1900 people/win.

Example 7 2.30 g of α-chloroacrylic acid 1-phenyl-2,2°2-trifluoroethyl ester.

0.70 g of α-chloroacrylic acid 2,2.2-)lifluoroethyl ester, 0.41 ml of benzene solution of azobisisobutyronitrile (contains 0.1vt% azobisisobutyronitrile), and benzene 3 0 ml was placed in a flask, and according to Example 5, a polymer was obtained. As a result of elemental analysis, the copolymerization ratio was 70/30 in terms of molar ratio. Moreover, the weight average molecular weight was 1.0×10B in terms of polystyrene as a result of GPC measurement.

Next, an electron beam sensitivity test was conducted, and it was found that when developing for 10 minutes using ethylene glycol monoethyl ether/isopropyl alcohol as a developer, the S value and γ
Each value is 15μC/c+j.

A positive type pattern of 4.5 was formed.

Further, when a dry etching resistance test was conducted for reactive sputtering 1 using CF4 gas, the etching rate was 2000 people/+1n.

Example 8 1.47 g of α-chloroacrylic acid 1-phenyl-2,2°2-trifluoroethyl ester.

0.53 g of α-chloroacrylic acid 2,2.3.3-tetrafluoropropyl ester, 0.26 ml of benzene solution of azobisisobutyronitrile (contains 0.1vt% azobisisobutyronitrile), and benzene 2.0m
1 was placed in a flask, and according to Example 5, a polymer was obtained.

As a result of elemental analysis, the copolymerization ratio was found to be 72/2 g in terms of molar ratio. In addition, the weight average molecular weight is the result of GPC measurement,
It was 1.6×10B in terms of polystyrene.

Next, we performed an electron beam sensitivity test and found that when developing for 1 minute using diisobutyl ketone/isopropyl alcohol as the developer, the S value and γ value were each 14μ.
A positive type pattern with C/cJ of 4.8 was formed. □Also, when a reactive sputtering test using CF4 gas and a dry etching resistance test for the ring were performed, the etching rate was 2000 people/jln.

[Effect of the invention] The halogen-containing polyacrylic acid ester derivative of the present invention,
In particular, the α-halo form has no 10 gene at the α-position.

It is an acrylic ester polymer containing a fluorine atom and a benzene ring in the ester moiety, and when irradiated with electron beams or X-rays, the main chain collapses. The solubility of is greatly improved.

Although polymethyl methacrylate and polyphenyl methacrylate also undergo main chain collapse due to these radiations, the halogen-containing polyacrylic ester derivatives of the present invention, especially the α-halo form, contain halogen at the α-position and the ester moiety. Because of this, it is easy for decay reactions to occur, resulting in increased sensitivity. Further, since the halogen-containing polyacrylic acid ester derivative of the present invention contains a benzene ring, it has excellent dry etching resistance.

[Brief explanation of the drawing]

Figure 1 shows polyα-chloroacrylic acid 1-phenyl-2
, 2,2-trifluoroethyl ester and its manufacturing raw material α-chloroacrylic acid 1-phenyl-2121
FIG. 2 is a diagram showing an infrared absorption spectrum of a 2,-trifluoroethyl ester monomer, and FIG. 2 is a diagram showing a C-NMR spectrum of the former. FIG. 3 shows infrared absorption spectra of polyα-chloroacrylic acid pentafluorophenyl ester and α-chloroacrylic acid pentafluorophenyl ester monomer, which is a raw material for its production, and FIG. 4 shows the 13C- NMR
It is a figure showing a spectrum. Figures 5 and 6 show the infrared absorption spectrum and C-NM of polymethacrylic acid pentafluorophenyl ester.
It is a figure showing an R spectrum. Patent applicant Toyo Soda Kogyo Co., Ltd. Figure 2 PPM Figure 4 Figure 6

Claims (9)

[Claims] (1) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (However, A indicates a constituent unit derived from a monomer having a copolymerizable double bond, and R is ▲ Numerical formulas, chemical formulas, tables, etc.) ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. methyl group; m is a positive integer; n is 0 or a positive integer; n/m is 0 to 2, preferably 0 to 1). (2) The halogen-containing polyacrylic ester derivative according to claim 1, wherein X is a chlorine atom. (3) The halogen-containing polyacrylic acid ester derivative according to claim 1, wherein X is a methyl group. (4) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (However, A indicates a constituent unit derived from a monomer having a copolymerizable double bond, R is ▲ Numerical formula, chemical formula, table, etc.) ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. or a methyl group. m is a positive integer, n is 0 or a positive integer. n/m is 0 to 2, preferably 0 to 1.) A halogen-containing polyacrylic ester derivative represented by 1. A method for forming a resist pattern, comprising using as a resist material. (5) The forming method according to claim 4, which uses a halogen-containing polyacrylic acid ester derivative in which X is a chlorine atom. (6) The formation method according to claim 4, which uses a halogen-containing polyacrylic acid ester derivative in which X is a methyl group. (7) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (However, A indicates a constitutional unit derived from a monomer having a copolymerizable double bond, and R is ▲ Numerical formula, chemical formula, table, etc.) ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. From a halogen-containing polyacrylic acid ester derivative represented by (represents a methyl group; m represents a positive integer; n represents 0 or a positive integer; n/m is 0 to 2, preferably 0 to 1); Resist material. (8) The resist material according to claim 7, comprising a halogen-containing polyacrylic acid ester derivative in which X is a chlorine atom. (9) The resist material according to claim 7, comprising a halogen-containing polyacrylic acid ester derivative in which X is a methyl group.