JPH05249678A - Radiation sensitive resin composition - Google Patents

Abstract

PURPOSE:To form a fine negative pattern by excimer laser or the like with high sensitivity and high resolution by containing a copolymer having a specific repeating unit and a repeating unit containing sulfonic group or the like. CONSTITUTION:The copolymer having the repeating unit expressed by a formula and the repeating unit containing sulfonic group and/or carboxylic group is contained. In the formula, R<1> is hydrogen atom, methyl group or haloalkyl group, R<2> is haloalkyl group, (n) is integer 1-3. Furthermore, in the formula, fluorine atom, chlorine atom, bromine atom and iodine atom is used as halogen atom contained in R<1> or of R<2> and the preferable halogen atom is chlorine atom. And 1-4C alkyl group, preferably methyl group is used as alkyl group constituting haloalkyl group in R<1> or of R<2>. The repeating unit expressed by the formula is either one kind or is in the coexistence of two or more kinds.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel radiation-sensitive resin composition which is particularly useful as a resist which can be finely processed by various radiations including deep ultraviolet rays such as excimer laser.

[0002]

2. Description of the Related Art In the field of microfabrication represented by the manufacture of integrated circuits, the processing size in lithography is being miniaturized in order to obtain a high degree of integration. There is a need for a technique that can reproducibly perform. Therefore, it is necessary to accurately form a pattern of 0.5 μm or less even in a resist used for microfabrication, but a conventional method using visible light (wavelength 700 to 400 nm) or near ultraviolet light (wavelength 400 to 300 nm) Then, 0.5 μm
It is extremely difficult to form the following fine patterns with high accuracy. Therefore, lithography that uses radiation having a shorter wavelength (wavelength of 300 nm or less) is being studied. Examples of such short-wavelength radiation include far-ultraviolet rays typified by the emission spectrum of a mercury lamp (wavelength 254 nm) and KrF excimer laser (wavelength 248 nm), X-rays typified by synchrotron radiation, and electrification typified by electron beams. Although there are particle beams and the like, of these, lithography using an excimer laser is particularly attracting attention as a "trump" for fine processing because of its high output and high efficiency characteristics. Therefore, the resist used for lithography is also 0.5 μm by the excimer laser.
The following fine patterns can be formed with high sensitivity and high resolution,
Good pattern profile, focus tolerance (a good pattern can be maintained even if the focus shifts during exposure), developability (less scum during development and less development residue),
It is required to be excellent in the residual film property (the film is not reduced during the development) and the adhesive property (the resist pattern is not peeled off during the development). However, with conventional resists,
It was not possible to reach the level of satisfying these conditions as a whole.

[0003]

Therefore, the problem to be solved by the present invention is that, even when various types of radiation including an excimer laser are used, the negative pattern is
It is an object of the present invention to provide a novel radiation sensitive resin composition that can achieve the above-mentioned various conditions required for a resist in a well-balanced manner.

[0004]

According to the present invention, the aforementioned problem is solved by a copolymer having a repeating unit represented by the following structural formula (I) and a repeating unit containing a sulfonic acid group and / or a carboxylic acid group. It is achieved by a radiation-sensitive resin composition comprising:

(Wherein R ¹ represents a hydrogen atom, a methyl group or a haloalkyl group, R ² represents a haloalkyl group, and n is 1
Is an integer of ~ 3. )

The present invention will be described in detail below, which will clarify the problems, constitutions and effects of the present invention.

In the structural formula (I), the halogen atom contained in the haloalkyl group of R ¹ or R ² includes a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a preferable halogen atom is a chlorine atom. Is. Examples of the alkyl group forming the haloalkyl group of R ¹ or R ² include an alkyl group having 1 to 4 carbon atoms, and a methyl group is preferable. The repeating unit represented by the structural formula (I) may be a single unit, or two or more types thereof may coexist.

Structural formula (I) in the copolymer of the present invention
Among the repeating units represented by, specific examples of preferred ones include o-chloromethylstyrene, m-chloromethylstyrene, p-chloromethylstyrene, o-dichloromethylstyrene, m-dichloromethylstyrene, p-dichloromethylstyrene. , O-trichloromethylstyrene, m-trichloromethylstyrene, p-trichloromethylstyrene, o-chloromethyl-α-methylstyrene, m-chloromethyl-α-methylstyrene, p-chloromethyl-α-methylstyrene, o -Dichloromethyl-
α-methylstyrene, m-dichloromethyl-α-methylstyrene, p-dichloromethyl-α-methylstyrene,
o-trichloromethyl-α-methylstyrene, m-trichloromethyl-α-methylstyrene, p-trichloromethyl-α-methylstyrene, o-chloromethyl-α-chloromethylstyrene, m-chloromethyl-α-chloromethyl Styrene, p-chloromethyl-α-chloromethylstyrene, o-dichloromethyl-α-chloromethylstyrene, m-dichloromethyl-α-chloromethylstyrene,
p-dichloromethyl-α-chloromethylstyrene, o-
Trichloromethyl-α-chloromethylstyrene, m-trichloromethyl-α-chloromethylstyrene, p-trichloromethyl-α-chloromethylstyrene, o-chloromethyl-α-dichloromethylstyrene, m-chloromethyl-α-dichloro Methylstyrene, p-chloromethyl-
α-dichloromethylstyrene, o-dichloromethyl-α
-Dichloromethylstyrene, m-dichloromethyl-α-
Dichloromethylstyrene, p-dichloromethyl-α-dichloromethylstyrene, o-trichloromethyl-α-dichloromethylstyrene, m-trichloromethyl-α-dichloromethylstyrene, p-trichloromethyl-α-dichloromethylstyrene, o- Chloromethyl-α-trichloromethylstyrene, m-chloromethyl-α-trichloromethylstyrene, p-chloromethyl-α-trichloromethylstyrene, o-dichloromethyl-α-trichloromethylstyrene, m-dichloromethyl-α-trichloro Methylstyrene, p-dichloromethyl-α-trichloromethylstyrene, o-trichloromethyl-α-trichloromethylstyrene, m-trichloromethyl-α-trichloromethylstyrene, p-trichloromethyl-α-trichloromethylstyrene, o, p -J Chloromethyl) styrene, 2,5-di (chloromethyl) styrene, 2,6
-Di (chloromethyl) styrene, 3,5-di (chloromethyl) styrene, o, p-di (dichloromethyl) styrene, 2,5-di (dichloromethyl) styrene, 2,6-
Di (dichloromethyl) styrene, 3,5-di (dichloromethyl) styrene, o, p-di (trichloromethyl) styrene, 2,5-di (trichloromethyl) styrene,
2,6-di (trichloromethyl) styrene, 3,5-di (trichloromethyl) styrene, o, p-di (chloromethyl) -α-methylstyrene, 2,5-di (chloromethyl) -α-methyl Styrene, 2,6-di (chloromethyl) -α-methylstyrene, 3,5-di (chloromethyl) -α-methylstyrene, o, p-di (dichloromethyl) -α-methylstyrene, 2,5 -Di (dichloromethyl) -α-methylstyrene, 2,6-di (dichloromethyl) -α-methylstyrene, 3,5-di (dichloromethyl) -α-methylstyrene, o, p-di (trichloromethyl) ) -Α-Methylstyrene, 2,5-di (trichloromethyl) -α-methylstyrene, 2,6-di (trichloromethyl) -α-methylstyrene, 3,5-di (trichloromethyl) -α-methylstyrene , O, p - di (chloromethyl)-.alpha.-chloromethylstyrene, 2,5-di (chloromethyl)-.alpha.-chloromethylstyrene, 2,6
-Di (chloromethyl) -α-chloromethylstyrene,
3,5-di (chloromethyl) -α-chloromethylstyrene, o, p-di (dichloromethyl) -α-chloromethylstyrene, 2,5-di (dichloromethyl) -α-chloromethylstyrene, 2, 6-di (dichloromethyl) -α-
Chloromethylstyrene, 3,5-di (dichloromethyl)
-Α-chloromethylstyrene, o, p-di (trichloromethyl) -α-chloromethylstyrene, 2,5-di (trichloromethyl) -α-chloromethylstyrene, 2,6
-Di (trichloromethyl) -α-chloromethylstyrene, 3,5-di (trichloromethyl) -α-chloromethylstyrene, 2,4,6-tri (chloromethyl) styrene, 2,4,6-tri ( Dichloromethyl) styrene,
2,4,6-tri (trichloromethyl) styrene, 2,
4,6-tri (chloromethyl) -α-methylstyrene,
2,4,6-tri (dichloromethyl) -α-methylstyrene, 2,4,6-tri (trichloromethyl) -α-methylstyrene, 2,4,6-tri (chloromethyl) -α
-Chloromethylstyrene, 2,4,6-tri (dichloromethyl) -α-chloromethylstyrene, 2,4,6-tri (trichloromethyl) -α-chloromethylstyrene,
2,4,6-Tri (chloromethyl) -α-dichloromethylstyrene, 2,4,6-tri (dichloromethyl) -α
-Dichloromethylstyrene, 2,4,6-tri (trichloromethyl) -α-dichloromethylstyrene, 2,4
6-tri (chloromethyl) -α-trichloromethylstyrene, 2,4,6-tri (dichloromethyl) -α-trichloromethylstyrene, 2,4,6-tri (trichloromethyl) -α-trichloromethylstyrene, etc. The repeating unit in which the double bond of is cleaved is mentioned. Among these repeating units, m-chloromethylstyrene, p-chloromethylstyrene, m-dichloromethylstyrene, p-dichloromethylstyrene, m-trichloromethylstyrene, p
-Trichloromethylstyrene, m-chloromethyl-α-
Repeating units in which a double bond is cleaved, such as methylstyrene and p-chloromethyl-α-methylstyrene, are particularly preferable.

The repeating unit represented by the structural formula (I) contains (i) at least one styrene derivative having a predetermined number of haloalkyl groups in the benzene ring, a sulfonic acid group and / or a carboxylic acid group. Method of copolymerizing with at least one monomer, (b) at least one of styrene and / or its derivative and at least one monomer containing a sulfonic acid group and / or a carboxylic acid group
It can be introduced by a method of haloalkylating the benzene ring of a precursor copolymer obtained by copolymerizing with a seed. In the case of (b), the styrene derivative in the precursor copolymer may contain a haloalkyl group in advance.

Specific examples of the repeating unit containing a sulfonic acid group and / or a carboxylic acid group in the copolymer of the present invention include vinyl sulfonic acid, isoprene sulfonic acid, styrene sulfonic acid, acrylic acid and methacrylic acid. , Maleic acid, itaconic acid, vinyl benzoic acid, styreneoxyacetic acid and the like in which the double bond is cleaved. These repeating units may be a single unit for each of those containing a sulfonic acid group and one containing a carboxylic acid group, or two or more kinds thereof may coexist.

The content of the repeating unit containing a sulfonic acid group and / or a carboxylic acid group varies depending on the type of developer used (alkaline aqueous solution, organic solvent, etc.), various characteristics of the resist, etc. Structural formula (I)
It is preferably from 15 to 70 mol%, more preferably from 20 to 50 mol%, based on the repeating unit represented by.

There are no particular restrictions on the polymerization method for producing a copolymer containing the repeating unit of structural formula (I) or a precursor copolymer thereof, and bulk polymerization, suspension polymerization, bulk-suspension polymerization, Any polymerization method such as emulsion polymerization or solution polymerization can be adopted. These polymerizations are carried out, for example, using a radical polymerization initiator and, if necessary, in the presence of a chain transfer agent. The polymerization temperature in this case varies depending on the decomposition temperature of the radical polymerization initiator, the molecular weight of the produced copolymer, etc., but is generally room temperature or higher and the boiling point of the reaction medium or lower. The preferred polymerization temperature is 40 to 100 ° C.

When the repeating unit of the structural formula (I) is introduced by the method (B), the precursor copolymer concentration is usually 1 to 50% by weight in the reaction medium in the presence of the Friedel-Crafts catalyst. , Haloalkylated. Formaldehyde and hydrogen halide, haloalkyl methyl ether, haloalkyl ethyl ether, dihaloalkyl methyl ether, trihaloalkyl methyl ether, etc. are used as the haloalkylating reagent. At that time, an excess amount of the haloalkylating reagent can be used as a reaction medium. Further, ethers such as tetrahydrofuran and dioxane can be used as the other reaction medium. The reaction temperature is preferably -10 to 40 ° C. As the Friedel-Crafts catalyst, boron trifluoride, aluminum chloride, aluminum bromide, zinc chloride, tin tetrachloride, titanium tetrachloride, ferric chloride, magnesium chloride, etc. are used. After introducing a predetermined amount of haloalkyl group, the Friedel-Crafts catalyst is decomposed in order to stop the reaction by adding water or water and a polar solvent such as dioxane to the reaction system.

The copolymer constituting the radiation-sensitive resin composition preferably has a high molecular weight in terms of sensitivity to radiation, and generally has a low molecular weight in terms of film-forming property as a resist. Is preferred. Therefore, the molecular weight of the copolymer constituting the radiation-sensitive resin composition of the present invention is also selected in consideration of these contradictory requirements, but it is generally a weight average molecular weight (hereinafter referred to as "Mw"). It is 3,000 to 500,000, preferably 5,000 to 100,000. Further, Mw / Mn of the copolymer (where "Mn" is the number average molecular weight).
Is generally 4.0 or less, preferably 2.0 or less.

The radiation-sensitive resin composition of the present invention means one containing the above-mentioned copolymer, and may or may not contain other additives. Therefore, it should be noted that the radiation-sensitive resin composition of the present invention includes both the copolymer alone and the mixture of the copolymer and other additives.

The radiation-sensitive resin composition of the present invention may contain a compound having a functional group capable of being crosslinked by radiation (hereinafter referred to as "crosslinkable functional group"), particularly an aromatic compound. , Thereby improving the sensitivity of the composition. Examples of the crosslinkable functional group include
^{R 5 CO (R 3 R 4} ) - group [provided that, R ³ and R ⁴ are good hydrogen atom or a methyl group which may be the same or different, R ⁵ is optionally a hydrogen atom be the same or different, 1 to 5 carbon atoms Alkyl group, aralkyl group having 7 to 13 carbon atoms, R ⁶ R ⁷ N-group (provided that R ⁶ and
R ⁷ may be the same or different, and may be an alkyl group having 1 to 4 carbon atoms or a cyclic group having 3 to 8 carbon atoms which may contain a hetero atom) or R ⁸ CO- group (wherein R ⁸ is the number of carbon atoms). 1-4 alkyl group or C6-C20 aryl group)], R ⁹
CO- group (wherein, R ⁹ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms) or ^{R 1 1 R 12 C = CR} 10 - group (wherein, R ^10,
R ¹¹ and R ¹² may be the same or different, such as a hydrogen atom or an alkyl group having 1 to 4 carbon atoms).

Specific examples of the crosslinkable functional group include glycidyl ether group, glycidyl ester group, glycidylamino group, methoxymethyl group, ethoxymethyl group, benzyloxymethyl group, dimethylaminomethyl group, diethoxymethylamino group, Examples thereof include morpholinomethyl group, acetoxymethyl group, benzoyloxymethyl group, formyl group, acetyl group, vinyl group and isopropenyl group. Specific examples of the aromatic compound having a crosslinkable functional group include bisphenol A epoxy compounds, bisphenol F epoxy compounds, bisphenol S epoxy compounds, novolac epoxy compounds, resol resin epoxy compounds, and polyhydroxystyrene epoxy compounds. Epoxy compound, methylol group-containing melamine resin, methylol group-containing benzoguanamine resin, methylol group-containing urea resin, methylol group-containing phenol resin, methylol group-containing melamine compound, methylol group-containing phenol compound, alkyl ether group-containing melamine resin, alkyl ether group-containing Benzoguanamine resin, alkyl ether group containing urea resin, alkyl ether group containing phenol resin, alkyl ether group containing melamine compound, alkyl ether group containing phenol Compounds, carboxymethyl group-containing melamine resins, carboxymethyl group-containing benzoguanamine resins, carboxymethyl group-containing urea resins, carboxymethyl group-containing phenol resin, carboxymethyl group-containing melamine compounds, carboxymethyl group-containing phenol compounds and the like. Of these, a methylol group-containing phenol resin, a methylol group-containing phenol compound, a methoxymethyl group-containing melamine compound, a methoxymethyl group-containing phenol compound, and an acetoxymethyl group-containing phenol compound are preferable. Particularly preferred is a methoxymethyl group-containing melamine compound, which is a CYM compound.
EL300, CYMEL301, CYMEL303, C
It is commercially available under the trade name of YMEL350 (manufactured by Mitsui Cyanamid).

When the compound having a crosslinkable functional group is blended, the amount used is generally 100 parts by weight or less, preferably 15 to 85 parts by weight, particularly preferably 15 to 85 parts by weight, based on 100 parts by weight of the copolymer of the present invention. It is preferably 20 to 75 parts by weight. When the compounding amount of the compound exceeds 100 parts by weight, scum increases and the developability tends to decrease. Further, when the compounding amount of the compound is 15 parts by weight or more, a sufficient cross-linked structure can be introduced, so that the reduction of the residual film rate, the meandering of the pattern, the swelling, etc. can be sufficiently suppressed.

The copolymer used in the radiation-sensitive resin composition of the present invention and the compound having a crosslinkable functional group may be used alone or in admixture of two or more.

Further, the radiation-sensitive resin composition of the present invention exhibits, if necessary, an effect of improving the coating property of the composition, striation, and the developability of the radiation-irradiated portion after the formation of a dry coating film. Surfactants, azo compounds or amine compounds showing antihalation action, adhesion aids, stabilizers,
Other additives such as defoaming agents can be added.

As described above, the radiation-sensitive resin composition of the present invention basically comprises the copolymer, and optionally the compound having the crosslinkable functional group and other additives. However, when forming a resist film, it is preferably prepared as a solution. Therefore, the radiation-sensitive resin composition as referred to in the present invention, in one embodiment, comprises the above-mentioned copolymer, and optionally the compound having the crosslinkable functional group and other additives as described above. It should be understood, however, that in still other embodiments, it can take the form of a solution of the composition.

In the radiation-sensitive resin composition of the present invention,
As the solvent used for forming the resist film,
Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, 2-methoxyethyl acetate, 2-ethoxyethyl acetate, Propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclohexanone, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, 2-
Ethyl hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl oxyacetate, 2-hydroxy-3-
Methyl methylbutanoate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-
Methyl-3-methoxybutylpropionate, 3-methyl-3-methoxybutylbutyrate, ethyl acetate, butyl acetate, methyl acetoacetate, ethyl acetoacetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, N -Methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, methyl pyruvate, ethyl pyruvate and the like can be mentioned.

The solvent may be benzyl ethyl ether, dihexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, acetonylacetone, isophorone, if necessary.
Caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzylalule, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, ethylene glycol monophenyl ether acetate, etc. A high boiling point solvent can also be added.

When the radiation-sensitive resin composition of the present invention is used as a solution, the solution is adjusted to a solid content concentration of, for example, 5 to 50% by weight, filtered, and then spin-coated or cast-coated.
A resist film is formed by applying it on the substrate by an appropriate method such as roll application.

To obtain a resist having a fine pattern using the radiation-sensitive resin composition of the present invention, the resist film formed as described above is partially exposed. Radiation for that purpose is not particularly limited. For example, the emission line spectrum of a mercury lamp (254 nm), the excimer laser (2
48 nm) and other deep ultraviolet rays, X such as synchrotron radiation
A charged particle beam such as a beam or an electron beam is used. Irradiation conditions such as radiation dose and irradiation time at that time are appropriately selected according to the compounding composition of the composition, the kind of additives and the like.

When the radiation-sensitive resin composition of the present invention is used, it may be heated after exposure in order to improve the apparent sensitivity of the resist. The heating condition is usually 30 to 200 ° C., preferably 50 to 100 ° C., though it varies depending on the composition of the composition, the type of additive and the like.

The resist film obtained from the radiation-sensitive resin composition of the present invention can be patterned by developing with a developing solution. As the developing solution, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia,
Ethylamine, n-propylamine, diethylamine,
Di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide,
Tetraethylammonium hydroxide, choline, pyrrole, piperidine, 1,8-diazabicyclo [5.4.
0] -7-undecene, 1,5-diazabicyclo-
[4.3.0] -5-Alkaline aqueous solution in which nonane, urea and the like are dissolved; or chloroform, trichloroethane,
Tetrachloroethane, benzene, toluene, xylene,
Organic solvents such as ethylbenzene, methyl ethyl ketone and cellosolve acetate can be used. Further, a water-soluble organic solvent (for example, alcohols such as methanol and ethanol), a surfactant and the like can be added to the alkaline aqueous solution.

[0027]

EXAMPLES The present invention will be described in more detail with reference to the following examples and comparative examples, but the present invention is not limited to these examples. Example 1 30 g of p-chloromethylstyrene, 22 g of methacrylic acid
Then, 0.8 g of azobisisobutyronitrile as a polymerization initiator was dissolved in 300 g of dioxane, the atmosphere in the reaction vessel was replaced with nitrogen, and polymerization was carried out at 65 ° C. for 6 hours. After completion of the polymerization, the reaction solution was dropped into hexane to precipitate a copolymer, and the precipitated copolymer was separated by filtration. Next, the step of dissolving the obtained copolymer in acetone, dropping the solution into hexane to precipitate the copolymer, and then filtering it off is repeated three times, and then the copolymer is placed in a vacuum dryer. Dried in. The produced copolymer has Mw = 15,000, Mw / Mn
= 1.84, and as a result of NMR measurement, it contained 47 mol% of the repeating unit of the structural formula (I). After dissolving 10 g of the obtained copolymer in 31 g of methyl 3-methoxypropionate, it was filtered through a filter having an eye diameter of 0.2 μm to prepare a copolymer solution. After coating this solution on a silicon wafer, baking at 100 ° C for 2 minutes,
A resist film having a film thickness of 1.0 μm was formed. This resist film was irradiated with an excimer laser having a wavelength of 248 nm at 30 mJ · cm ⁻² by using a stepper, and then at 6 ° C. with a tetramethylammonium hydroxide aqueous solution at 23 ° C.
It was developed for 0 seconds and then washed with water for 30 seconds. When the obtained resist pattern was observed with a scanning electron microscope, a negative pattern of 0.4 μm line and space was formed with a good pattern profile.
The focus tolerance, residual film property, developability and adhesiveness were also good.

Example 2 Hexamethylmethoxymelamine condensate (CYM) having an average degree of condensation of 1.5 was added to 20 g of the copolymer solution prepared in Example 1.
1 g of EL303, manufactured by Mitsui Cyamide Co., Ltd.) was added to prepare a copolymer solution, which was then treated in the same manner as in Example 1 to form a resist film. This resist film was irradiated with an excimer laser of 10 mJ · cm ⁻² using a stepper, and then developed and washed in the same manner as in Example 1 to form a resist pattern. The obtained negative pattern was a 0.4 μm line-and-space pattern, and the pattern profile was also good. Further, the focus tolerance, the residual film property, the developability and the adhesive property were also good.

Comparative Example 30 g of p-chloromethylstyrene and 0.4 g of azobisisobutyronitrile were dissolved in 200 g of dioxane, the atmosphere in the reaction vessel was replaced with nitrogen, and polymerization was carried out at 65 ° C. for 6 hours. After completion of the polymerization, the reaction solution was dropped into hexane to precipitate a polymer, and the precipitated polymer was separated by filtration. Next, the step of dissolving the obtained polymer in acetone, dropping the solution into hexane to precipitate the polymer, and then filtering it off is performed.
Repeated times and finally dried in a vacuum dryer. The produced polymer had Mw = 23,000 and Mw / Mn = 1.63, and as a result of NMR measurement, it was found to consist of only the repeating unit of the structural formula (I). 10 g of the obtained polymer is m
-After being dissolved in 36 g of xylene, it was filtered with a filter having an eye diameter of 0.2 µm to prepare a polymer solution. This solution was applied on a silicon wafer and baked at 100 ° C. for 2 minutes to form a resist film having a film thickness of 1.0 μm. This resist film is irradiated with 30 mJ · cm ⁻² of excimer laser having a wavelength of 248 nm using a stepper, and then 2
Developed with ethoxyethyl acetate for 60 seconds at 23 ° C. and then washed with isopropyl alcohol for 30 seconds. Observation of the obtained negative resist with a scanning electron microscope revealed that the line and
It was confirmed that the space pattern could not be formed. Further, there is a large amount of undeveloped residue, and there is a problem in developability.

[0030]

As described in detail above, the radiation-sensitive resin composition of the present invention has an excimer laser (wavelength of 248 μm).
Negative fine pattern can be formed with high sensitivity and high resolution by far-ultraviolet rays such as X-rays, X-rays such as synchrotron radiation, and wide range of short-wavelength radiation such as charged particle beams such as electron beams. It is also excellent in acceptability, developability, residual film property, adhesiveness and the like. Therefore, it is extremely useful as a resist for manufacturing a highly integrated semiconductor device, which is expected to be further miniaturized in the future, and can be effectively used as a general resist.

Front Page Continuation (72) Inventor Takao Miura 2-11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd.

Claims (1)

[Claims] 1. A radiation-sensitive resin composition comprising a copolymer having a repeating unit represented by the following structural formula (I) and a repeating unit containing a sulfonic acid group and / or a carboxylic acid group. object. [Chemical 1] (In the formula, R ¹ represents a hydrogen atom, a methyl group or a haloalkyl group, R ² represents a haloalkyl group, and n is an integer of 1 to ^3. )