JPH11160876A - Positive radiation sensitive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the positive radiation sensitive composition having high resolution capable of matching the quarter micron lithography using light in the far ultraviolet region and controlling a shift amount of resist width between sparse and dense patterns by incorporating a resin increasing in solubility in an aqueous solution by action of an acid and a compound to be allowed to generate an acid by light or electron beams and a specified orthoester compound. SOLUTION: The positive radiation sensitive resin composition contains the resin increasing in solubility in an aqueous solution by action of an acid and the compound to be allowed to generate an acid by light or electron beams and the orthoester compound represented by the formula in which R<1> is an H atom or an optionally substituted hydrocarbon group; and each of R<2> -R<4> is, independently, an optionally substituted hydrocarbon group. Line width change of >=10% of a mask size is necessary to effectively control the resist line width, thus permitting the shift amount of >=20% of the resist line width to be realized by this method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation-sensitive positive-type radiation-sensitive composition. For more information,
The present invention relates to a positive photoresist having high sensitivity and high resolution to light in the far ultraviolet region.

[0002]

2. Description of the Related Art As the degree of integration of a semiconductor integrated circuit is generally increased four times in three years as generally known, for example, dynamic random access memory (DR)
AM) as an example, full-scale production of a memory having a storage capacity of 64 Mbits has now started. Accordingly, the demand for photolithography technology, which is indispensable for the production of integrated circuits, has been increasing year by year. For example, it is expected that lithography at the level of 0.3 μm is required for the production of a 64 Mbit DRAM, and lithography at the level of 0.25 μm is required for a 256 Mbit DRAM with a higher degree of integration. I have. Along with this, the wavelength used for exposing the resist also changed from the g-line (436 nm) of the mercury lamp to the i-line (365 n).
m), and further shortening the wavelength to KrF excimer laser light (248 nm). However, in a conventional positive photoresist using naphthoquinonediazide as a photosensitizer, K
It has a very low transmittance for light in the far ultraviolet region, such as rF excimer laser light, resulting in low sensitivity and low resolution.

As a new positive resist which solves such a problem, various chemically amplified positive photoresists comprising a photoacid generator and a compound whose solubility in an alkali developing solution is increased by an acid catalyzed reaction have been proposed. Have been. By the way, in an actual semiconductor device manufacturing process, there may be a part where patterns are dense and a part where patterns are sparse. In such a case, since the optical image obtained through the mask at the time of exposure is different between a sparse part and a dense part, the line width of a resist pattern obtained from a mask pattern having the same line width will be different. . In order to correct the shift amount of the resist line width between the dense / dense patterns, there is a method of applying a bias to the mask, and the shift amount of the resist line width between the dense / dense patterns is different depending on the type of the resist. In addition, it is often inconvenient because it is necessary to change the mask according to the type of the resist, and it is not possible to apply a bias depending on the pattern arrangement. Therefore, there is a need for a method of adjusting the shift amount of the resist line width between the dense and dense patterns by controlling the characteristics of the resist.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high resolution capable of responding to quarter-micron lithography using light in the far ultraviolet region which has solved the above-mentioned problems of the prior art, and to control the characteristics of the resist. The object of the present invention is to provide a positive-type radiation-sensitive composition capable of adjusting the shift amount of the resist line width between the dense and dense patterns.

[0005]

In order to increase the resolution of a chemically amplified positive photoresist, the acid generated by exposure effectively acts to increase the change in the alkali solubility of the resist film with respect to the amount of exposure. is necessary. Further, as a problem peculiar to the chemically amplified resist, the diffusion length of the acid generated by the exposure in the resist film affects the resolution. That is, if the acid does not diffuse in the resist film, the acid catalyzed reaction proceeds only in the vicinity of the generated acid, and sufficient sensitivity and resolution cannot be obtained. Conversely, if the diffusion length of the acid in the resist film is extremely long, the acid-catalyzed reaction proceeds even in the non-exposed part, causing deterioration of the pattern shape and resolution.

As described above, controlling the diffusion length of an acid generated by exposure in a resist film is an important factor for determining the sensitivity, resolution and pattern shape of a chemically amplified resist. However, it also plays an important role in adjusting the shift amount of the resist line width between the dense and dense patterns. As a specific method for controlling the diffusion length of an acid in a resist film, a method of adding an organic base or the like is known. However, the addition of an organic base has the disadvantage that the acid is neutralized thereby leading to a reduction in sensitivity.

We have studied various methods for controlling the acid diffusion length in a resist film. As a result, by adding an orthoester compound having a specific structure, the acid diffusion length can be controlled without lowering the sensitivity. As a result, it has been found that the resolution and the pattern shape can be improved, and the shift amount of the resist line width between the dense and dense patterns can be adjusted.

That is, the gist of the present invention is a resin having an acid labile group and increasing the solubility in an aqueous alkali solution by the action of an acid, a compound capable of generating an acid by light or electron beam, and a compound represented by the following general formula (I). The positive-type radiation-sensitive resin composition comprises an orthoester compound.

[0009]

Embedded image

(Wherein R¹Is a hydrogen atom or substituted
Represents an optionally substituted hydrocarbon group;^Two, R ^Three, R^FourEach
May be the same or different, may be substituted
Represents a hydrocarbon group. In general, the line width reproducibility of the resist pattern depends on the mask size.
It is about plus or minus 10%. Therefore, the present invention
To effectively control the resist line width, which is the purpose of
In order to achieve this, a line width change of 10% or more of the mask size is required.
Yes, according to the method of the present invention, a resist line width of 20% or more
Can be realized.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
In the present invention, as a resin having an acid labile group and having increased solubility in an aqueous alkali solution by the action of an acid,
There is no particular limitation as long as the exposed portion becomes alkali-soluble due to the action of the acid generated by the exposure, elutes in the alkaline developer during development, and has an ability to form a uniform resist film. For example, a resin obtained by homopolymerizing hydroxystyrene or copolymerizing hydroxystyrene with various vinyl monomers such as styrene or acrylic acid, or a hydroxyl group or a carboxyl group of an alkali-soluble resin that is a derivative thereof is an acid labile group. A protected resin can be used. The acid labile group is not particularly limited, as long as it can be removed at room temperature or by heating after exposure (post-exposure bake) with an acid generated from the photoacid generator at the time of exposure to regenerate a hydroxyl group or a carboxyl group. For example, methoxymethoxy, 1-methoxyethoxy, 1-methoxypropoxy, 1-methoxybutoxy, 1-ethoxyethoxy, 1-ethoxypropoxy, 1-ethoxybutoxy, tetrahydrofuranyloxy, tetrahydropyrani An acetal group such as a loxy group, a ketal group such as a 1-methoxy-1-methylethoxy group, a carbonate group such as a t-butoxycarbonyloxy group, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, n-butoxy group,
tert-butoxy group, n-amyloxy group, alkoxy group such as iso-amyloxy group, acyloxy group such as acetoxy group, or methylsulfonyloxy group, ethylsulfonyloxy group, trifluoromethylsulfonyloxy group, benzenesulfonyloxy group, p -A sulfonyloxy group such as a toluenesulfonyloxy group is used, and these acid labile groups may be used in combination. Of these, an acetal group or a carbonate group is preferred, and an acetal group is particularly preferred.

When the resin having an acid labile group and having increased solubility in an aqueous alkali solution by the action of an acid is a resin in which the phenolic hydroxyl group of polyhydroxystyrene is protected by an acid labile group, Specifically, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, 2- (o-hydroxyphenyl) propylene, 2- (m-hydroxyphenyl)
A resin obtained by polymerizing one or more hydroxystyrenes such as propylene and 2- (p-hydroxyphenyl) propylene in the presence of a radical polymerization initiator, an anionic polymerization initiator or a cationic polymerization initiator is preferably used. Further, a resin which has been subjected to hydrogenation in order to reduce the absorbance of the resin after polymerization may be used.

The weight average molecular weight (Mw) of the resin having an acid labile group and increasing the solubility in an aqueous alkali solution by the action of an acid is within a range in which a resist film can be formed and developed with an alkali developing solution after exposure. Although not particularly limited, it is preferably 3,000 in terms of polystyrene (measured by gel permeation chromatography).
Those having a size of not less than 60,000 and not more than 4,000 are more preferable.

When the weight average molecular weight of the resin is larger than this range, the solubility of the exposed portion in an alkali developing solution becomes small, and a good resist pattern cannot be obtained.
If the weight average molecular weight of the resin is smaller than this range, a good resist coating film cannot be obtained. As the compound that generates an acid by radiation such as light or an electron beam used in the composition of the present invention, any compound that generates an acid by light or an electron beam used for exposure can be used, Specifically, for example, tris (trichloromethyl) -s-triazine, tris (tribromomethyl) -s-triazine, tris (dibromomethyl) -s
-Triazine, 2,4-bis (tribromomethyl) -6
Halogen-containing s-triazine derivatives such as -p-methoxyphenyl-s-triazine, 1,2,3,4-tetrabromobutane, 1,1,2,2-tetrabromoethane,
Halogen-substituted paraffinic hydrocarbons such as carbon tetrabromide and iodoform, halogen-substituted cycloparaffinic hydrocarbons such as hexabromocyclohexane, hexachlorocyclohexane and hexabromocyclododecane, bis (trichloromethyl) benzene, bis (tribromomethyl)
Halogen-containing benzene derivatives such as benzene, halogen-containing sulfone compounds such as tribromomethylphenylsulfone, trichloromethylphenylsulfone and 2,3-dibromosulfolane, and halogen-containing isocyanurate derivatives such as tris (2,3-dibromopropyl) isocyanurate , Triphenylsulfonium chloride, triphenylsulfonium methanesulfonate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium p-toluenesulfonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluoroarsenate, triphenylsulfonium hexafluorophosphonate and the like Sulfonium salt, diphenyliodonium trifluoromethanesulfo Over, diphenyl iodonium p-
Iodonium salts such as toluenesulfonate, diphenyliodonium tetrafluoroborate, diphenyliodonium hexafluoroarsenate, diphenyliodonium hexafluorophosphonate, methyl p-toluenesulfonate, ethyl p-toluenesulfonate, p
-Butyl toluenesulfonate, phenyl p-toluenesulfonate, 1,2,3-tri (p-toluenesulfonyloxy) benzene, p-toluenesulfonic acid benzoin ester, methyl methanesulfonate, ethyl methanesulfonate, methanesulfonic acid Butyl, 1,2,3-tri (methanesulfonyloxy) benzene, phenyl methanesulfonate, benzoin methanesulfonate, methyl trifluoromethanesulfonate, ethyl trifluoromethanesulfonate, butyl trifluoromethanesulfonate, 1,2,3 Sulfonic acid esters such as tri (trifluoromethanesulfonyloxy) benzene, phenyl trifluoromethanesulfonate and benzoin trifluoromethanesulfonate; o-nitrobenzyl-p-toluenesulfur O-nitrobenzyl sulfonic acid esters such as carboxylate, sulfone hydrazides such as N, N'-di (phenylsulfonyl) hydrazide, disulfones such as diphenyldisulfone, bis (phenylsulfonyl) methane, bis (p-methoxyphenylsulfonyl) ) Methane, bis (p-toluylsulfonyl) methane, bis (2,6-dimethylphenylsulfonyl) methane, bis (cyclohexylsulfonyl) methane, phenylsulfonyl (cyclohexylsulfonyl) methane, p
Bissulfonylmethanes such as -methoxysulfonyl (cyclohexylsulfonyl) methane, and bissulfonyldiazomethanes.

Of these acid generators, a sulfonium salt whose counter anion is a sulfonate anion, an iodonium salt whose counter anion is a sulfonate anion,
Compounds that generate sulfonic acid by light or electron beam, such as sulfonic acid esters, o-nitrobenzylsulfonic acid esters, sulfone hydrazides, bissulfonylmethanes, and bissulfonyldiazomethanes. Of these compounds that generate sulfonic acid by light or electron beam, bisulfonyldiazomethanes are particularly preferred. Specific examples of bissulfonyldiazomethanes that can be suitably used include cyclohexylsulfonyl-
(O-methoxyphenylsulfonyl) diazomethane, cyclohexylsulfonyl- (m-methoxyphenylsulfonyl) diazomethane, cyclohexylsulfonyl-
(P-methoxyphenylsulfonyl) diazomethane, cyclopentylsulfonyl- (o-methoxyphenylsulfonyl) diazomethane, cyclopentylsulfonyl-
(M-methoxyphenylsulfonyl) diazomethane, cyclopentylsulfonyl- (p-methoxyphenylsulfonyl) diazomethane, cyclohexylsulfonyl-
(O-fluorophenylsulfonyl) diazomethane, cyclohexylsulfonyl- (m-fluorophenylsulfonyl) diazomethane, cyclohexylsulfonyl-
(P-fluorophenylsulfonyl) diazomethane, cyclopentylsulfonyl- (o-fluorophenylsulfonyl) diazomethane, cyclopentylsulfonyl-
(M-fluorophenylsulfonyl) diazomethane, cyclopentylsulfonyl- (p-fluorophenylsulfonyl) diazomethane, cyclohexylsulfonyl-
(O-chlorophenylsulfonyl) diazomethane, cyclohexylsulfonyl- (m-chlorophenylsulfonyl) diazomethane, cyclohexylsulfonyl- (p-
(Chlorophenylsulfonyl) diazomethane, cyclopentylsulfonyl- (o-chlorophenylsulfonyl) diazomethane, cyclopentylsulfonyl- (m-chlorophenylsulfonyl) diazomethane, cyclopentylsulfonyl- (p-chlorophenylsulfonyl) diazomethane, cyclohexylsulfonyl- (o-trifluoromethylphenylsulfonyl) Diazomethane, cyclohexylsulfonyl- (m-trifluoromethylphenylsulfonyl) diazomethane, cyclohexylsulfonyl-
(P-trifluoromethylphenylsulfonyl) diazomethane, cyclopentylsulfonyl- (o-trifluoromethylphenylsulfonyl) diazomethane, cyclopentylsulfonyl- (m-trifluoromethylphenylsulfonyl) diazomethane, cyclopentylsulfonyl- (p-trifluoromethylphenylsulfonyl) ) Diazomethane, cyclohexylsulfonyl- (o-trifluoromethoxyphenylsulfonyl) diazomethane, cyclohexylsulfonyl- (m-trifluoromethoxyphenylsulfonyl) diazomethane, cyclohexylsulfonyl- (p-trifluoromethoxyphenylsulfonyl) diazomethane, cyclopentylsulfonyl- (o −
(Trifluoromethoxyphenylsulfonyl) diazomethane, cyclopentylsulfonyl- (m-trifluoromethoxyphenylsulfonyl) diazomethane, cyclopentylsulfonyl- (p-trifluoromethoxyphenylsulfonyl) diazomethane, cyclohexylsulfonyl- (2,4,6-trimethylphenylsulfonyl) Diazomethane, cyclohexylsulfonyl- (2,3,4-
Trimethylphenylsulfonyl) diazomethane, cyclohexylsulfonyl- (2,4,6-triethylphenylsulfonyl) diazomethane, cyclohexylsulfonyl- (2,3,4-triethylphenylsulfonyl) diazomethane, cyclopentylsulfonyl- (2,4,6
-Trimethylphenylsulfonyl) diazomethane, cyclopentylsulfonyl- (2,3,4-trimethylphenylsulfonyl) diazomethane, cyclopentylsulfonyl- (2,4,6-triethylphenylsulfonyl)
Diazomethane, cyclopentylsulfonyl- (2,3,
4-triethylphenylsulfonyl) diazomethane, phenylsulfonyl (o-methoxyphenylsulfonyl)
Diazomethane, phenylsulfonyl (m-methoxyphenylsulfonyl) diazomethane, phenylsulfonyl (p-methoxyphenylsulfonyl) diazomethane, bis (o-methoxyphenylsulfonyl) diazomethane,
Bis (m-methoxyphenylsulfonyl) diazomethane, bis (p-methoxyphenylsulfonyl) diazomethane, phenylsulfonyl- (2,4,6-trimethylphenylsulfonyl) diazomethane, phenylsulfonyl- (2,3,4-trimethylphenylsulfonyl) Diazomethane, phenylsulfonyl- (2,4,6-triethylphenylsulfonyl) diazomethane, phenylsulfonyl- (2,3,4-triethylphenylsulfonyl) diazomethane, 2,4-dimethylphenylsulfonyl- (2,4,6-trimethyl Phenylsulfonyl) diazomethane, 2,4-dimethylphenylsulfonyl-
Examples thereof include (2,3,4-trimethylphenylsulfonyl) diazomethane, phenylsulfonyl (o-fluorophenylsulfonyl) diazomethane, phenylsulfonyl (m-fluorophenylsulfonyl) diazomethane, and phenylsulfonyl (p-fluorophenylsulfonyl) diazomethane. These acid generators may be used alone or as a mixture of two or more of them.

The composition of the present invention is characterized by containing an orthoester compound. As the orthoester compound, any compound can be used without particular limitation as long as it is a compound represented by the general formula (I). Specifically, R ¹ is a hydrogen atom, an optionally substituted methyl group, or an ethyl group. , N-
Propyl group, iso-propyl group, n-butyl group, se
c-butyl group, tert-butyl group, n-amyl group, i
so-amyl group, cyclopentyl group, n-hexyl group,
A chain or cyclic carbon number 1 such as a cyclohexyl group
10 alkyl groups, an optionally substituted phenyl group,
An aryl group having 6 to 10 carbon atoms such as a toluyl group, a 1-naphthyl group, a 2-naphthyl group, a 2-propenyl group, a 2-butenyl group, a 2-methyl-2-propenyl group, a 3-methyl-2-butenyl group. , An allyl group such as a 2,3-dimethyl-2-butenyl group or the like,
And 10 substituted allyl groups. the above,
Examples of the substituent of the alkyl group, the aryl group, and the allyl group include a methoxy group, an ethoxy group, an n-propoxy group, and an iso-
Alkoxy groups such as propoxy groups, hydroxyl groups, nitro groups,
Examples include an amino group.

Also, R^Two, R^Three, R^FourAs methyl
Group, ethyl group, n-propyl group, iso-propyl group,
n-butyl group, sec-butyl group, tert-butyl
Group, n-amyl group, iso-amyl group, cyclopentyl
Group, n-hexyl group, cyclohexyl group, etc.
Or a cyclic alkyl group having 1 to 20 carbon atoms,
Phenyl group, toluyl group, α-naphthyl group, β
An aryl group having 6 to 20 carbon atoms such as a naphthyl group,
Propenyl group, 2-butenyl group, 2-methyl-2-pro
Phenyl group, 3-methyl-2-butenyl group, 2,3-dimethyl
An allyl group such as a tyl-2-butenyl group or
A substituted allyl group having 3 to 20 carbon atoms, which is substituted with an arbitrary substituent
And the like. The above alkyl group and aryl
Alkoxy group, aryl
Oxy groups, hydroxyl groups, nitro groups, amino groups, etc.
Can be. Examples of the alkoxy group include a methoxy group and ethoxy.
Xy group, n-propoxy group, iso-propoxy group, n
-Butoxy group, sec-butoxy group, tert-butoxy
Si group, n-pentyloxy group, n-hexyloxy group,
Cyclopentyloxy group, cyclohexyloxy group, etc.
And the aryloxy group may be
Nyloxy group, toluyloxy group, α-naphthyloxy
And a β-naphthyloxy group.
Preferred R^Two~ R ^FourAs R^Five-OR⁶− (R^FiveIs
C1-C10 alkyl group, C6-C10 aryl
R 3 represents an aryl group or an allyl group having 3 to 10 carbon atoms;⁶Is charcoal
(Showing an alkylene group having a prime number of 1 to 10).
Preferably, the present invention is not limited to this.

It is possible to increase the line width of an isolated line by adding the orthoester compound. By adjusting the amount of addition, the amount of line width shift from the line and space resist line width can be adjusted. can do. The orthoester compound preferably has a boiling point of 200 ° C. or higher at normal pressure. If the boiling point is too low, sufficient effects cannot be obtained because they are volatilized by baking after resist application or baking after exposure (post-exposure bake).

In the radiation-sensitive resin composition of the present invention, 100 parts by weight of a resin having an acid labile group and having an increased solubility in an aqueous alkali solution due to the action of an acid are added to the resin by radiation such as light or electron beam. Is used in an amount of 0.01 to 20 parts by weight, preferably 0.1 to 10 parts by weight, and the orthoester compound represented by the general formula (I) is 0.1 to 30 parts by weight, preferably 0.1 to 30 parts by weight. Is 0.5 ~
Used in a proportion of 20 parts by weight.

If the amount of the compound that generates an acid by radiation such as light or an electron beam is less than the above range, the sensitivity becomes extremely low, and it is not practical. If the amount of the compound that generates an acid by radiation such as light or an electron beam is larger than this range, the sensitivity becomes extremely high, which is not practical. If the amount of the orthoester compound is less than the above range, a sufficient effect cannot be obtained, and if the amount is more than the above range, the heat resistance is reduced.

The composition of the present invention is usually used by dissolving these components in a suitable solvent. The solvent is not particularly limited as long as it has a sufficient solubility to the photoacid generator and the resin and gives good coating properties, and examples thereof include 2-hexanone, 2-heptanone, and cyclohexanone. Ketone solvents, methyl cellosolve, ethyl cellosolve, cellosolve solvents such as methyl cellosolve acetate, ethyl cellosolve acetate, diethyl oxalate, ethyl pyruvate, ethyl-2-hydroxybutyrate,
Ethyl acetoacetate, butyl acetate, amyl acetate, ethyl butyrate, butyl butyrate, methyl lactate, ethyl lactate, 3-
Ester solvents such as methyl methoxypropionate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol dimethyl ether, etc. Or a mixed solvent thereof, or a solvent further containing an aromatic hydrocarbon. The ratio of the solvent used is 1 to 20 as a weight ratio with respect to the total amount of the solid content in the photosensitive agent composition.
Preferably, the range is twice as large.

The composition of the present invention may contain various additives usually used for photoresists, in addition to the above-mentioned resin, acid generator and orthoester. For example, a surfactant may be added to improve the coatability. Further, tri-i is used as a diffusion control agent for the acid generated by exposure.
Amines such as propanolamine may be added.
The resolution is improved by the addition of the amine.

When a resist pattern is formed on a semiconductor substrate using the positive-type radiation-sensitive resin composition of the present invention, the positive-type photosensitive composition of the present invention dissolved in a solvent as described above is usually used. It is applied on a semiconductor substrate and undergoes the steps of pre-bake, pattern transfer by exposure, post-exposure bake, and development. The semiconductor substrate is generally used as a substrate for manufacturing a semiconductor, and is a silicon substrate, a gallium arsenide substrate, or the like.

A spin coater is usually used for coating,
For exposure, light of 436 nm and 365 nm of a high pressure mercury lamp,
254 nm of a low-pressure mercury lamp, 157 nm, 193 nm, 222 nm, 248 n using an excimer laser or the like as a light source
m light or electron beam is preferably used. Light at the time of exposure may be broad instead of monochromatic light. Also,
Exposure by the phase shift method is also applicable.

The developer of the positive photoresist composition of the present invention includes sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate,
Inorganic alkalis such as aqueous ammonia, ethylamine, n
Primary amines such as -propylamine, secondary amines such as diethylamine and di-n-propylamine, tertiary amines such as triethylamine, N, N-diethylmethylamine, tetramethylammonium hydroxide, A quaternary ammonium salt such as trimethylhydroxyethylammonium hydroxide, or a quaternary ammonium salt to which an alcohol, a surfactant or the like is added can be used. The positive photoresist composition of the present invention is useful not only for the production of VLSI, but also for general IC production, mask production, image formation, liquid crystal screen production, color filter production or offset printing.

[0026]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited by the examples unless it exceeds the gist thereof. Synthesis Example 1 (Synthesis of tetrahydropyranylated polyvinyl phenol) Polyvinyl phenol (weight average molecular weight 4140) was placed in a 1 L four-necked flask equipped with a nitrogen inlet tube, a stirrer, and a thermometer.
0) 30 g and ethyl acetate (300 mL) were added and dissolved uniformly, then dihydropyran (21.0 g) was added, and the mixture was heated to 40 ° C in a water bath. To this, 0.3 g of 36% hydrochloric acid was added, and stirring was continued for 4 hours. After the reaction, the reaction solution was extracted with 400 mL of a 1% aqueous sodium hydrogen carbonate solution. After drying this organic layer with anhydrous sodium sulfate,
It was concentrated to about 100 mL with a rotary evaporator. This concentrated solution was poured into 1 L of n-hexane to recover a polymer. The precipitated polymer was dried under vacuum to obtain 34.3.
g of tetrahydropyranylated polyvinylphenol was obtained. The obtained polymer was dissolved in deuterated acetone, and the proton NMR spectrum was measured.
Aromatic-hydrogen signal of 7.0 and a δ value of 5.2-5.5
Area ratio with the acetal methine hydrogen signal is 1
0.81: 1. From this result, the acetalization rate was 37.0%.

Synthesis Example 2 (Synthesis 1 of 1-ethoxyethylated polyvinylphenol 1) Polyvinylphenol (weight average molecular weight 4140) was placed in a 1 L four-necked flask equipped with a nitrogen inlet tube, a stirrer, and a thermometer.
0) 30 g and ethyl acetate (300 mL) were added and uniformly dissolved, and then ethyl vinyl ether (15.3 g) was added, followed by heating to 40 ° C. in a water bath. In addition, 36
% Hydrochloric acid was added, and stirring was continued for 4 hours. After the reaction,
The reaction solution was extracted with 400 mL of a 1% aqueous sodium hydrogen carbonate solution. The organic layer was dried over anhydrous sodium sulfate, and then concentrated to about 100 mL using a rotary evaporator. This concentrated solution was poured into 1 L of n-hexane to recover a polymer. The precipitated polymer is dried under vacuum and
6.4 g of 1-ethoxyethylated polyvinylphenol were obtained. The obtained polymer was dissolved in deuterated acetone, and the proton NMR spectrum was measured. As a result, a signal of an aromatic hydrogen having a δ value of 6.2 to 7.0 and a δ value of 5.2 to 5.2 were obtained.
The area ratio to the acetal methine hydrogen signal of 5.5 was 9.90: 1. From this result, the acetalization ratio was 40.4%.

Synthesis Example 3 (Synthesis 2 of 1-ethoxyethylated polyvinylphenol 2) In the same manner as in Synthesis Example 2, 30 g of polyvinylphenol (weight average molecular weight 17200) and ethyl vinyl ether 1
From 6.0 g and 300 mL of ethyl acetate as a reaction solvent, 39.8 g of 1-ethoxyethylated polyvinylphenol was obtained. When the proton NMR spectrum of the obtained polymer was measured, the area ratio between the signal of aromatic hydrogen having a δ value of 6.2 to 7.0 and the signal of acetal methine hydrogen having a δ value of 5.2 to 5.5 was calculated as follows. 11.05: 1. From this result, the acetalization rate was 36.2.
%.

Synthesis Example 4 (Synthesis of tri (phenoxyethyl) orthoacetate) In a 50 ml four-necked flask, 4.06 g (25 mmol) of triethyl orthoacetate, 13.82 g (100 mmol) of 2-phenoxyethanol and p-toluenesulfonic acid 1 Hydrate at 150 ° C.
Allowed to react for hours. Thereafter, a rectifying tube was attached to the reaction vessel to distill off ethanol. The reaction solution was further stirred at 200 ° C. for 3 hours. After completion of the reaction, the reaction solution was allowed to cool to room temperature and diluted with 100 ml of tetrahydrofuran. 2 g of anhydrous potassium carbonate was added to this solution, and the mixture was stirred for 1 hour. The potassium carbonate was filtered off, and the filtrate was concentrated with a rotary evaporator. This concentrated solution was distilled under reduced pressure (final bath temperature 1).
At 80 ° C., a final pressure of 15 mmHg), the low-boiling substances and unreacted 2-phenoxyethanol were distilled off to obtain 8.21 g of tri (phenoxyethyl) orthoacetate.

Synthesis Example 5 (Synthesis of tri (phenoxyethyl) orthobenzoate) In the same manner as in Synthesis Example 4, 5.61 g (25 mmol) of triethylorthobenzoate, 13.82 g (100 mmol) of 2-phenoxyethanol and p-toluenesulfonic acid 1 9.34 g of tri (phenoxyethyl) orthobenzoate was obtained from 11 mg of the hydrate.

EXAMPLE 1 1.00 g of the resin synthesized in Synthesis Example 1, 0.02 g of cyclohexylsulfonyl (p-methoxyphenylsulfonyl) diazomethane as a photoacid generator, tri (phenoxyethyl) orthoacetate synthesized in Synthesis Example 4 0.1
0 g, tri-iso-propanolamine 0.001 g
Then, 5.5 g of propylene glycol monomethyl ether acetate was mixed as a solvent to obtain a resist photosensitive solution. This photosensitive solution was spin-coated on a silicon substrate and baked on a hot plate at 90 ° C. for 60 seconds to form a film having a thickness of 0.1 μm.
The resist film was 72 μm. The resist film on the silicon substrate was exposed at an energy amount of 48 mJ / cm ² using a KrF excimer laser reduction projection exposure apparatus (NA = 0.42) manufactured by Nikon Corporation.
Bake at 60 ° C for 60 seconds. Thereafter, the resist film was developed with a 2.38% by weight aqueous solution of tetramethylammonium hydroxide for 1 minute. The resolution and pattern shape were evaluated by observing the resist pattern obtained after the development with a scanning electron microscope. As a result, 0.28 μm
Was resolved with a good shape, and the line width of the 0.30 μm line and space was 0.298 μm, and the line width of the 0.20 μm isolated line was 0.221 μm. . In addition, when the position of the focal point of the exposure apparatus was changed during the exposure with the optimum exposure amount, the range of the focal point where the corresponding pattern was resolved was evaluated as the depth of focus. The 0.30 μm line and space has a depth of focus of 1.6 μm and 0.20 μm.
The depth of focus of a μm isolated line was 0.8 μm.

Example 2 A resist pattern was prepared and evaluated in the same manner as in Example 1 except that 0.10 g of tri (phenoxyethyl) orthobenzoate synthesized in Synthesis Example 5 was used instead of tri (phenoxyethyl) orthoacetate. did. Table 1 shows the results.
It was shown to.

Example 3 0.9 g of the resin of Synthesis Example 2, cyclohexylsulfonyl (p-methoxyphenylsulfonyl) diazomethane 0.
02 g, tri (phenoxyethyl) orthoacetate 0.10 g, tri-iso-propanolamine 0.0
01 g and 5.5 g of propylene glycol monomethyl ether acetate as a solvent were mixed to obtain a resist photosensitive solution. A resist pattern was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 4 0.9 g of the resin of Synthesis Example 3 and cyclohexylsulfonyl (p-methoxyphenylsulfonyl) diazomethane 0.
02 g, 0.10 g of tri (phenoxyethyl) orthoacetate, 0.0017 g of bis (2-hydroxyethyl) aminotris (hydroxymethyl) methane and 5.5 g of propylene glycol monomethyl ether acetate as a solvent were mixed to obtain a resist photosensitive solution. . A resist pattern was prepared and evaluated in the same manner as in Example 1.
The results are shown in Table 1.

Example 5 The amount of tri (phenoxyethyl) orthoacetate was reduced to 0.
A resist photosensitive solution was prepared and evaluated in the same manner as in Example 4 except that the amount was 025 g. The results are shown in Table 1.

Example 6 Instead of tri (phenoxyethyl) orthoacetate, tri (phenoxyethyl) orthobenzoate 0.02
A resist photosensitive solution was prepared and evaluated in the same manner as in Example 4 except that 0 g was used. The results are shown in Table 1.

Example 7 A resist solution was prepared in the same manner as in Example 4, except that 0.07 g of triphenylsulfonium p-toluenesulfonate was used as a photoacid generator instead of cyclohexylsulfonyl (p-methoxyphenylsulfonyl) diazomethane. Was prepared and evaluated. The results are shown in Table 1.

Comparative Example 1 A resist photosensitive solution was prepared and evaluated in the same manner as in Example 1 except that tri (phenoxyethyl) orthoacetate was not added. The results are shown in Table 1.

Comparative Example 2 A resist photosensitive solution was prepared and evaluated in the same manner as in Example 4 except that tri (phenoxyethyl) orthoacetate was not added. The results are shown in Table 1.

Comparative Example 3 A resist photosensitive solution was prepared and evaluated in the same manner as in Example 7 except that tri (phenoxyethyl) orthoacetate was not added. The results are shown in Table 1.

[0041]

[Table 1]

[0042]

The radiation-sensitive composition containing the orthoester according to the present invention has a high resolution in lithography using KrF excimer laser light and controls the shift amount of the line width between the dense and dense patterns. The ability is excellent.

Claims (8)

[Claims] 1. An alcohol having an acid labile group by the action of an acid.
Resins, light or electrons that increase solubility in aqueous solutions
A compound which generates an acid by a ray and a compound represented by the following general formula (I)
Characterized by containing an orthoester compound represented by
Positive radiation-sensitive resin composition. Embedded image(Where R¹Is a hydrogen atom or an optionally substituted char
Represents a hydride group, R^Two, R ^Three, R^FourAre the same
Hydrocarbon groups which may be different and may be substituted
Represents ) 2. A general formula (I), R ¹ is a hydrogen atom, an alkyl group which may be substituted, may be substituted aryl group or an optionally substituted allyl group, R ^2, R ³ and R ⁴ may be the same or different, and each represents an optionally substituted alkyl group, an optionally substituted aryl group, or an optionally substituted allyl group. 2. The positive radiation-sensitive resin composition according to item 1. 3. In the general formula (I), R ¹ is a hydrogen atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, an optionally substituted aryl group having 6 to 10 carbon atoms or A substituted or unsubstituted allyl group having 3 to 10 carbon atoms, wherein R ² , R ³ and R ⁴ may be the same or different, and may be substituted having 1 to 20 carbon atoms The positive radiation-sensitive radiation according to claim 2, wherein the radiation is an alkyl group, an optionally substituted aryl group having 6 to 20 carbon atoms, or an optionally substituted allyl group having 3 to 20 carbon atoms. Resin composition. 4. In the general formula (I), R ¹ is a hydrogen atom, an unsubstituted alkyl group having 1 to 10 carbon atoms, an unsubstituted aryl group having 6 to 10 carbon atoms, or an allyl group; R ² , R ³ , and R ⁴ may be the same or different, and each represents an unsubstituted alkyl group having 1 to 20 carbon atoms, an unsubstituted aryl group having 6 to 20 carbon atoms, an allyl group, or R ⁵ —OR ⁶ — group (wherein R ⁵ has 1 carbon atom)
Represents an alkyl group having at least 10 or less, an aryl group having at least 6 and at most 10 carbon atoms, or an allyl group optionally having at least 3 and at most 10 carbon atoms, and R ⁶ represents an alkylene group having at least 1 and at most 10 carbon atoms. . The positive-type radiation-sensitive resin composition according to claim 3, which is a group represented by the formula: 5. An acid labile group of a resin having an acid labile group and having increased solubility in an aqueous alkali solution by the action of an acid, wherein the acid labile group is an acetal group, a ketal group, a carbonate group, an alkoxy group, a carboxyl group, or a sulfoxyl group. The positive-type radiation-sensitive resin composition according to any one of claims 1 to 4, wherein 6. The positive radiation-sensitive resin composition according to claim 1, wherein, in the compound that generates an acid by light or electron beam, the generated acid is sulfonic acid. 7. The positive-type radiation-sensitive resin according to claim 1, wherein the orthoester compound represented by the general formula (I) has a boiling point of 200 ° C. or more at normal pressure. Composition. 8. An orthoester compound is used in an amount of 0.1 to 30 parts by weight per 100 parts by weight of a resin having an acid labile group and having increased solubility in an aqueous alkali solution due to the action of an acid.
2. The composition according to claim 1, wherein the content is not more than part by weight.
8. The positive-type radiation-sensitive resin composition according to any one of claims 1 to 7.