JPH0542658B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a negative X-ray resist used in X-ray lithography. In the semiconductor integrated circuit manufacturing industry, resist is considered to be an important factor that influences the degree of integration and productivity of semiconductor integrated circuits. In recent years, as the degree of integration of semiconductor integrated circuits has increased, the conventional method of forming a resist image by exposing it to ultraviolet light and developing it, and then wet-etching the substrate other than the resist image area, has changed. A shift is now being made to a method in which a resist image is formed using ionizing radiation as a radiation source, which causes less reduction in resolution due to diffraction phenomena, and is then etched by dry etching using plasma etching or reactive ion etching. With these changes in technology, electron beams, deep ultraviolet rays, X-rays, and the like are being considered as radiation sources. However, when electron beams are used, a decrease in resolution due to diffraction phenomenon is not a problem, but since patterns are drawn over a large area by scanning a narrowly focused electron beam, productivity is poor when mass producing semiconductor integrated circuits. There is a drawback. On the other hand, far ultraviolet rays can be irradiated all at once, so there is no problem with productivity, but since the wavelength is at most about 250 nm, there is a problem with the resolution limit due to the phenomenon of light diffraction. On the other hand, X-rays have a short wavelength of 0.1 to 100 Å, and have the advantage of being able to be irradiated all at once. Conventionally, polyglycidyl methacrylate and the like have been known as X-ray resists, but they have many drawbacks such as low sensitivity due to low X-ray absorption efficiency and lack of dry etching resistance. . The object of the present invention is to use an X-ray resist film that has high sensitivity to X-rays, can form fine resist images with high precision, and has high resistance to dry etching.
The purpose is to provide line resist. The X-ray resist of the present invention has the following general formula (A) ^In _the ^formula _, ^{_ _ 5} independently represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms (hereinafter referred to as
(hereinafter simply referred to as "alkyl group"), alkoxy group having 1 to 3 carbon atoms (hereinafter simply referred to as "alkoxy group"), halogen atom, haloalkyl having 1 to 3 carbon atoms (hereinafter simply referred to as "haloalkyl group") or a haloalkoxy group having 1 to 3 carbon atoms (hereinafter simply referred to as "haloalkoxy group"), the repeating structural unit represented by accounts for at least 80 mol% of the total repeating structural units of the polymer, and ( 1) In the above formula (A), X is a halogen atom (hereinafter referred to as (A-1)); (2) In the above formula (A), R ¹ , R ² , R ³ , R ⁴ and
A repeating structural unit ( ^hereinafter referred to as (A-
2)), and (3) has a repeating structural unit (hereinafter referred to as (A-3)) in which at least one of Y ₁ and Y ₂ in the above formula (A) is a halogen atom, (2) the halogen atoms are 9.0 to 28.8% by weight of the polymer, and the number average molecular weight is 3.0 x ¹⁰⁵ to 15.0 x ¹⁰⁵ ,
It is characterized by containing the polymer as an X-ray sensitive polymer. In the present invention, X is a halogen atom,
It is represented by the general formula (A) in which at least one of R ¹ , R ² , R ³ , R ⁴ and R ⁵ is a haloalkyl group or a haloalkoxy group, and at least one of Y ₁ and Y ₂ is a halogen The repeating structural unit is (A-
1), (A-2) and (A-3). Similarly, X is a halogen atom, at least one of Y ₁ and Y ₂ is a halogen, and R ¹ , R ² , R ³ , R ⁴ and R ⁵ are hydrogen atoms, alkyl groups, alkoxy groups, or halogen atoms. In the case of a repeating structural unit represented by general formula (A), it is treated as either (A-1) or (A-3). In the repeating structural unit represented by general formula (A),
Examples of R ¹ , R ² , R ³ , R ⁴ and R ⁵ include hydrogen atom, methyl group, ethyl group, propyl group, methoxy group, ethoxy group, propoxy group, chlorine atom, bromine atom, iodine atom, fluorine atom, Atom, methyl chloride group, methyl bromide group, methyl iodide group, ethyl chloride group, propyl chloride group, methoxy chloride group, methoxy bromide group, methoxy iodide group, ethoxy chloride group, propoxy chloride group, methyl dichloride group , methyl dibromide group, methyl diiodide group, ethyl dichloride group, ethyl dibromide group, propyl dichloride group, propyl dibromide group, methoxy dichloride group, methoxy dibromide group, methoxy diiodide group, ethoxy dichloride group, ethoxy dibromide group, propoxy dichloride group, propoxy dibromide group, methyl trichloride group, methyl tribromide group, ethyl trichloride group, ethyl tribromide group, methoxy trichloride group , methoxy tribromide, etc., especially R ¹ , R ² , R ³ ,
It is preferable that one of R ⁴ and R ⁵ is a methyl group, a methyl chloride group, a methyl bromide group, a methyl dichloride group or a methyl dibromide group, and the other is a hydrogen atom. Further, examples of the halogen atom represented by X, Y ₁ and Y ₂ in the general formula (A) include a chlorine atom, a bromine atom, an iodine atom, and a fluorine atom. Other repeating structural units that can form a copolymer with the repeating structural unit represented by general formula (A) include, for example, ethyl acrylate units, butyl acrylate units, glycidyl acrylate units, α
- Unsaturated ethylene compound units such as vinylnaphthalene units, β-vinylnaphthalene units, 2-vinylpyridine units, 4-vinylpyridine units, maleic anhydride units, vinyl acetate units, conjugated diene compounds such as butadiene units, isoprene units, etc. Examples include units and halogenated units of these units. For sensitivity to X-rays and resistance to dry etching, these repeating units account for the total number of repeating units in the copolymer.
Preferably it is less than 20 mol%. The total halogen content in the polymer in the X-ray resist of the present invention is 9 to 28.8% by weight. If the total halogen content is less than 9% by weight, the absorption efficiency for X-rays will decrease, and if it exceeds 28.8% by weight, image bleeding will occur when used as a resist to form a fine resist image, that is, the pattern will be blurred. It also becomes sensitive to weak X-rays that pass through the X-ray shielding part of the mask, resulting in a decrease in resolution. The molecular weight of the polymer in the X-ray resist of the present invention is preferably high in order to maintain high sensitivity to X-rays, and from the viewpoint of handling for forming a coating film as a resist, the molecular weight The lower the value, the better. The number average molecular weight range that satisfies these two contradictory requirements is 3.0×10 ⁵ to 15.0×10 ⁵ . If the number average molecular weight is less than 3.0×10 ⁵ , the sensitivity to X-rays is low, and if it exceeds 15.0×10 ⁵ , the viscosity of the solution becomes high, making it impossible to form a uniform coating film when used as a resist. . The X-ray resist of the present invention has the general formula (B) (In the formula, R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ mean a hydrogen atom, an alkyl group or an alkoxy group, provided that all of R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ are Except in the case of a hydrogen atom. Also, Z ₁ , Z ₂ and Z ₃ mean a hydrogen atom, a fluorine atom or a methyl group, provided that Z ₁
When is a methyl group, Z ₂ and Z ₃ mean a hydrogen atom. ), or this and general formula (C) (In the formula, Z ₄ , Z ₅ and Z ₆ mean a hydrogen atom, a fluorine atom or a methyl group. However, if Z ₁ of the repeating structural unit shown in general formula (B) is a methyl group, Z ₄
means a hydrogen atom. ) can be produced by radically halogenating a polymer containing a repeating structural unit represented by the formula, for example, with a halogenating agent in the presence of a radical generator or under irradiation with light or ultraviolet rays. . Next, methods (1) and (2) will be shown as specific examples. (1) General formula (D) (In the formula, R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ and Z ₁ , Z ₂ and Z ₃ are the same as in general formula (B).), or a monomer represented by this and general formula ( E) (In the formula, Z ₄ , Z ₅ and Z ₆ are the same as in general formula (C).)
A monomer containing the monomer represented by is polymerized or copolymerized. The resulting polymer is then dissolved or swollen in a solvent as described in, for example, Journal of the American Chemical Society, 82 , 108 (1960).
t-Butyl hypochlorite, t-butyl hypoiodite in the presence of a radical generator such as 4'-azobisisobutyronitrile, benzoyl peroxide, lauroyl peroxide, etc. or under irradiation with light or ultraviolet light. , chlorine, bromine, and other compounds capable of generating halogen radicals. (2) Polymerize or copolymerize a monomer represented by general formula (D) or a monomer containing this and a monomer represented by general formula (E), and then polymerize the obtained polymer. , for example, Journal of American
Chemical Society, 74 , 2189 (1952), N-chlorosuccinimide, N- Radical halogenation is performed using an N-halogen compound such as bromosuccinimide or N-bromoacetamide. In the method (1) or (2), examples of the monomer represented by the general formula (D) include o-methylstyrene, m-methylstyrene, p-methylstyrene,
Examples include p-ethylstyrene and p-methoxystyrene. Two or more of these monomers may be used in combination. Examples of the monomer represented by general formula (E) include α-methylstyrene and styrene. These monomers may be used in combination. Furthermore, examples of other monomers copolymerizable with the monomer represented by general formula (D) or the monomer represented by general formula (E) include ethyl (meth)acrylate, (meth) ) butyl acrylate, (meth)glydicyl acrylate, etc.
Acrylic acid ester, α-vinylnaphthalene, β
-vinylnaphthalene, 2-vinylpyridine, 4-
Examples include aromatic vinyl compounds other than monomers represented by general formula (D) or (E) such as vinylpyridine, conjugated diene compounds such as butadiene and isoprene, and unsaturated ethylene compounds such as maleic anhydride and vinyl acetate. be able to. In addition, the general formula in the polymer to be halogenated
The ratio of the repeating structural units represented by (B) to the total repeating structural units is preferably 20 to 100 mol%, particularly 30 to 100 mol%, in order to improve sensitivity to X-rays, and is represented by general formula (C). The proportion of the repeating structural unit to the total repeating structure is 0 to 80 mol%, especially 0
~70 mol% is preferred. In method (1) or (2), the solvent for radically halogenating the polymer is preferably one that does not interact with halogen radicals, such as carbon tetrachloride, 1,1,2-trichloroethane, etc. , halogenated hydrocarbons such as carbon tetrabromide, benzene and the like are particularly suitable. The degree of halogenation in method (1) or (2) is usually determined by the amount of the compound capable of generating halogen radicals used in method (1), and the amount of N-halogen compound used in method (2). It is adjusted depending on the amount used, etc. In the method (1) or (2), the concentration of the halogenated polymer in the reaction solution is 3 to 20% by weight,
When a radical generator is used, the amount of the radical generator used is preferably 0.01 to 5 parts by weight per 100 parts by weight of the polymer to be halogenated, and the reaction temperature is preferably 40 to 200°C. In addition, when halogenating by irradiating light or ultraviolet rays, the irradiation amount of light or ultraviolet rays can be adjusted as appropriate depending on the degree of halogenation. Additives such as stabilizers can be added to the X-ray resist of the present invention. Examples of stabilizers include hydroquinone, methoxyphenol, p-t-
Butylcatechol, 2,2'-methylenebis(6-
Hydroxy aromatic compounds such as t-butyl-4-ethylphenol), quinones such as benzoquinone, p-toluquinone, p-xyquinone, phenyl-
Amines such as α-naphthylamine, p,p'-diphenylphenylenediamine, dilaurylthiodipropionate, 4,4'-thiobis(6-t-butyl-3-methylphenol), 2,2'- Thiobis(4-methyl-6-t-butylphenol), 2-
(3,5-di-t-butyl-4-hydroxyanilino)-4,6-bis(N-octylthio)-s-
Examples include sulfur compounds such as triazine. The amount of these added is usually about 0.5 to 5% by weight. The X-ray resist of the present invention is usually handled in the form of a solution in a petroleum fraction such as xylene, ethylbenzene, toluene, etc., a chlorinated solvent such as trichloroethane, tetrachloroethane, or a polar solvent such as methyl isobutyl ketone or cellosolve acetate. Although the concentration of the X-ray resist in this case cannot be absolutely defined, it is determined depending on the film thickness when applied, and is generally used as a 5 to 30% by weight solution. According to the present invention, irradiation with specific X-rays such as rhodium Lα rays, aluminum Kα rays, palladium Lα rays,
Provides a negative X-ray resist that becomes insoluble in the phenomenon liquid by irradiation with soft X-rays using a synchroton, has high sensitivity, high resistance to dry etching, and has significantly improved resolution. can do. Next, the present invention will be explained in more detail with reference to Examples. Example 1 A magnetic stirring bar was placed in a four-necked round bottom flask with an internal volume of 2, the inside of the system was replaced with nitrogen, and 320 g of cyclohexane and 35.4 g of p-methylstyrene were added under a nitrogen stream.
to make the system a homogeneous solution, and then lower the internal temperature to 50℃.
I kept it. This solution was then diluted with n-
Polymerization was initiated by adding 0.60 ml of a 0.50 mol/cyclohexane solution of butyllithium. The polymerization rate reached 92.0% after 120 minutes. Furthermore, the reaction solution
The polymer was recovered by placing it in a methanol solution containing 2,6-di-t-butyl-p-cresol and heated at 40°C.
It was dried under reduced pressure for 16 hours. 11.8 g of the polymer thus obtained was placed in a round bottom flask, and the system was purged with nitrogen, followed by 236 g of benzene, 96 mg of 4,4'-azobisisobutyronitrile, and t-hypochlorous acid. 10.9 g of butyl was added, and the system was kept at 70°C and reacted for 90 minutes. The reaction product was placed in a methanol solution containing 2,2'-methylenebis(6-t-butyl-4-methylphenol) to separate and recover the halide. When the obtained halide was analyzed using a nuclear magnetic resonance apparatus (JMN-4H-100 model manufactured by JEOL Ltd.), δ = 2.2 ppm was found in the raw material polymer.
Peaks derived from hydrogen of nearby methyl groups and δ
It was found that the peak derived from the hydrogen of the methine group around 1.8 ppm became smaller. Also ¹³ C−
Nuclear magnetic resonance apparatus (JNM-FX-100 type manufactured by JEOL Ltd.)
When analyzed using
Absorption due to dichloromethyl group was observed at 71.8 ppm, and further at δ = 68 to 76 ppm.

Broad absorption due to [Formula] and δ = 51 to 55 ppm
to

Absorption caused by [Formula] was observed. This revealed that the methyl groups of the polymer and the methine and methylene groups in the main chain were chlorinated. The halide thus obtained is (A
It was confirmed that the following repeating structural units belonging to -1), (A-2) and (A-3) were present.

【formula】

【formula】

【formula】

[Formula] The chlorine content is 20.9% by weight, and the number average molecular weight measured by a membrane osmometer is 6.0×10 ⁵
It was hot. The halide obtained above is mixed with xylene.
A 4.8% by weight solution was prepared, and this solution was placed on a silicon wafer with a 0.7 μm thermal oxidation layer.
2 seconds at revolutions/minute, then 30 seconds at 4000 revolutions/minute,
Spin coated. When the wafer was further heat-treated at 80° C. for 30 minutes to scatter the solvent, a 0.5 μm coating film was formed on the wafer. This sample was irradiated with aluminum Kα rays as X-rays through a mask, developed with cellosolve acetate for 1 minute, and rinsed with a mixed solution of methyl ethyl ketone/isopropanol (1:1) for 1 minute. As a result, 14mJ/ ^cm2
It was found that an image of 0.6 μm could be resolved faithfully to the mask with an X-ray irradiation energy of . Example 2 A magnetic stirring bar was placed in a four-necked round bottom flask with an internal volume of 2, the inside of the system was replaced with nitrogen, and 320 g of cyclohexane and 35.4 g of p-methylstyrene were added under a nitrogen stream.
to make the system a homogeneous solution, and then lower the internal temperature to 50℃.
I kept it. This solution was then diluted with n-
0.25 mol of butyllithium in cyclohexane solution. Polymerization was started by adding 45 ml. The polymerization rate reached 100% after 120 minutes. Furthermore, the reaction solution was added to 2,
The polymer was recovered by placing it in a methanol solution containing 6-di-t-butyl-p-cresol and heated at 40°C for 16
Dry under reduced pressure for an hour. 11.8 g of the polymer thus obtained was placed in a round bottom flask, and the system was purged with nitrogen, followed by 236 g of benzene, 96 mg of 4,4'-azobisisobutyronitrile, and t-hypochlorous acid. 4.1 g of butyl was added, and the system was kept at 70°C and reacted for 90 minutes. The reaction product was placed in a methanol solution containing 2,2'-methylenebis(6-t-butyl-4-methylphenol) to separate and recover the halide. When the structure of the halide was analyzed in the same manner as in Example 1, (A-1), (A-2) and (A
It was confirmed that it had the following repeating structural unit belonging to -3).

【formula】

【formula】

[Formula] The chlorine content is 9.0% by weight, and the number average molecular weight measured by a membrane osmometer is 4.0×10 ⁵
It was hot. The halide obtained above is mixed with xylene.
A 5.5% by weight solution was prepared, and this solution was placed on a silicone wafer with a 0.7 μm thermal oxidation layer.
Spin coating was performed at 200 rpm for 2 seconds and then at 4000 rpm for 30 seconds. After further heat treatment at 80℃ for 30 minutes to scatter the solvent, 0.5μm of
A coating film was formed. This sample was irradiated with aluminum Kα rays as X-rays through a mask, developed with cellosolve acetate for 1 minute, and rinsed with a mixed solution of methyl ethiketone/isopropanol (1:1) for 1 minute. This result is 40m
It was found that an image of 0.6 μm could be resolved faithfully to the mask with an X-ray irradiation energy of J/cm ² . Example 3 A magnetic stirring bar was placed in a four-necked round bottom flask with an internal volume of 2, the inside of the system was replaced with nitrogen, and 577 g of cyclohexane, 49.9 g of styrene, and 14.2 g of o-methylene styrene were placed in a nitrogen stream. After making a homogeneous solution, the internal temperature was maintained at 60°C. Next, 2.4 ml of a 0.25 mol/cyclohexane solution of n-butyllithium was added to this solution under a nitrogen stream to initiate polymerization. The polymerization rate reached 100% after 60 minutes.
Furthermore, the reaction solution was added to 2,2′-methylenebis(6-
The polymer was recovered by placing it in a methanol solution containing t-butyl-4-ethylphenol) and incubated at 40°C for 16
Dry under reduced pressure for an hour. 10.7 g of the polymer thus obtained was placed in a round bottom flask, and the system was purged with nitrogen, followed by 230 g of benzene, 96 mg of 4,4'-azobisisobutyronitrile, and 20.0 g of N-chlorosuccinimide.
was added, and the system was kept at 70°C and reacted for 1.5 hours.
The reaction product was converted into 2,2'-methylenebis(6-t-
The mixture was placed in a methanol solution containing (butyl-4-ethylphenol) to separate and recover the halide. When the structure of the halide was analyzed in the same manner as in Example 1, (A-1), (A-2) and (A
It was confirmed that it had the following repeating structural unit belonging to -3).

【formula】

【formula】

【formula】

【formula】

【formula】

[Formula] The chlorine content is 28.8% by weight, and the number average molecular weight measured by a membrane osmometer is 3.0×10 ⁵
It was hot. The halide obtained above is mixed with xylene.
A solution of 8.5% by weight was placed on a silicon wafer with a thermal oxidation layer of 0.7μm, and
2 seconds at revolutions/minute, then 30 seconds at 4000 revolutions/minute,
Spin coated. When the wafer was further heat-treated at 80°C for 30 minutes to scatter the solvent, a coating film of 0.5 μm was formed on the wafer. After irradiating this sample with aluminum Kα rays as X-rays through Max,
The film was developed with cellosolve acetate for 1 minute, and rinsed with a mixed solution of methyl ethyl ketone/isopropanol (1:1) for 1 minute. As a result, 13mJ/
It was found that an image of 0.6 μm can be resolved faithfully to the mask with an X-ray irradiation energy of cm ² . Comparative Example 1 A magnetic stirring bar was placed in a four-necked round bottom flask with an internal volume of 2, the inside of the system was replaced with nitrogen, and 481 g of cyclohexane and 52 g of styrene were put in a nitrogen stream to make the inside of the system a homogeneous solution. The temperature was maintained at 60℃.
Next, 1.42 ml of a 0.25 mol/cyclohexane solution of n-butyllithium was added to this solution under a nitrogen stream to initiate polymerization. The reaction temperature rose to 70.5°C, and the polymerization rate reached 100% after 120 minutes. Further, the reaction solution was placed in a methanol solution containing 2,2'-methylenebis(6-t-butyl-4-ethylphenol), and the polymer was recovered and dried under reduced pressure at 40°C for 16 hours. 10.4 g of the polymer obtained in this way was placed in a round bottom flask, and after purging the system with nitrogen, 224 g of carbon tetrachloride, 9.7 mg of benzoyl peroxide and 60 g of t-butyl hypochlorite were added. The system was kept at 90°C and reacted for 4 hours. The reaction product, 2,
The halide was separated and recovered by placing it in a methanol solution containing 2'-methylenebis(6-t-butyl-4-ethylphenol). When the structure of the halide was analyzed in the same manner as in Example 1, it was confirmed that it has the following repeating structural units belonging to (A-1) and (A-3), and (A-2) does not exist. This was confirmed.

【formula】

[Formula] The chlorine content is 11.8% by weight, and the number average molecular weight measured by a membrane osmometer is 6.5×10 ⁵
It was hot. Using the halide obtained above, it was coated on a silicone wafer with a thermally oxidized layer in the same manner as in Example 1, and was further irradiated with aluminum Kα rays as X-rays, developed, and rinsed. As a result, it was finally possible to resolve images of 5 μm or more with an X-ray irradiation energy of 120 mJ/cm ² . Comparative Example 2 A magnetic stirring bar was placed in a four-neck round bottom flask with an internal volume of 2, the inside of the system was replaced with nitrogen, and 481 g of cyclohexane and 52 g of styrene were put in a nitrogen stream to make the inside of the system a homogeneous solution. was kept at 60℃. Next, 0.8 ml of a 0.25 mol/cyclohexane solution of n-butyllithium was added to this solution under a nitrogen stream to initiate polymerization. The reaction temperature rose to 70.5°C, and the polymerization rate reached 100% after 120 minutes. Further, the reaction solution was poured into a methanol solution containing 2,2'-methylenebis(6-t-butyl-4-ethylphenol) to recover the polymer, which was dried under reduced pressure at 40°C for 16 hours. 10.4 g of the polymer thus obtained was placed in a round bottom flask, and after purging the system with nitrogen, 400 ml of chloromethyl methyl ether was added and stirred to form a homogeneous solution. Next, while maintaining this solution at 0° C., 4.0 ml of tin tetrachloride dissolved in 50 ml of chloromethyl methyl ether was added dropwise and reacted for 60 minutes. The reaction product was placed in a methanol solution containing 2,2'-methylenebis(6-t-butyl-4-ethylphenol), and the product was separated and recovered. When the structure of the product was analyzed in the same manner as in Example 1, it was confirmed that it had the following repeating structural unit belonging to (A-2), and that (A-1) and (A-3) did not exist. was confirmed. In addition, the chlorine content is 21.1% by weight, and the number average molecular weight measured by a membrane osmometer is 6.0×10 ⁵
It was hot. Using the product obtained above, it was coated on a silicon wafer with a thermal oxidation layer in the same manner as in Example 1, and then irradiated with aluminum Kα rays as X-rays through a mask in the same manner as in Example 1. , developed with cellosolve acetate for 1 minute, and rinsed with a mixed solution of methyl ethyl ketone/isopropanol (1:1) for 1 minute. As a result, 80m
A 2.0 μm image was obtained with an X-ray irradiation energy of J/cm ² . It can be seen that the sensitivity and resolution are inferior compared to the examples. Examples 4 to 6 and Comparative Examples 3 to 7 Using a polymer obtained by polymerizing p-methylstyrene in the same manner as in Example 1 by changing the amount of the cyclohexane solution of n-butyllithium in Example 1, Halogenation was carried out in the same manner as in Example 1, except that 4,4'-azobisisobutyronitrile in Example 1 was replaced with lauroyl peroxide, and the amount of t-butyl hypochlorite used and the reaction time were changed. (A-1), (A-2) and (A-
A halide having a repeating structural unit belonging to 3) was obtained. Next, using the halide obtained above, a solution having the concentration shown in Table 2 was coated on a silicon wafer with a thermally oxidized layer in the same manner as in Example 1 to form a coating film of 0.5 μm. This coating film was irradiated with X-rays shown in Table 2, developed in the same manner as in Example 1, and rinsed. The resolution and irradiation energy are also shown in Table 2.

【table】

[Table] Note (1): Poor developability and development residue occurred Test Example The dry etching resistance of the resist patterns obtained in Examples 1 to 3 was tested. The dry etching resistance test was conducted using a parallel plate dry etching device (electrode spacing of 40 mm) as an etching gas.
The test was conducted using CF ₄ /O ₂ (95/5 volume ratio) at an output of 100 W and a gas pressure of 15 Pa. When the etching rate of PMMA (polymethyl methacrylate) is set to 1, the relative rates are as shown in Table 3. It was found that the dry etching resistance was good.

【table】

Claims (1)

[Claims] 1 General formula (A) In the formula, X is a hydrogen atom, a methyl group, or a halogen atom; ^Y ₁ and Y ₂ are each independently a hydrogen atom, a methyl ^group , or ^a halogen ^atom ; R ⁵ are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, and 1 carbon number.
~3 alkoxy groups, halogen atoms, 1 carbon number
-3 haloalkyl group or C1-3 haloalkoxy group, the repeating structural unit represented by accounts for at least 80 mol% of the total repeating structural units of the polymer, and (1) the above formula (A) (2) a repeating structural unit in which X is a halogen atom, (2) R ¹ , R ² , R ³ , R ⁴ and
A repeating structural unit in which at least one of R ⁵ is a haloalkyl group having 1 to 3 carbon atoms or a haloalkoxy group having 1 to 3 carbon atoms, and (3) at least one of Y ₁ and Y ₂ in the above formula (A) has a repeating structural unit in which is a halogen atom, (2) the halogen atom is 9.0 to 28.8% by weight of the polymer, and (3) the number average molecular weight is 3.0×10 ⁵ to 15.0×10 ⁵ .
An X-ray resist characterized by containing a polymer as an X-ray sensitive polymer.