JPH10186663A - Positive photoresist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the positive photoresist composition capable of sensitization development superior in various performances, such as, resistance to dimensional fluctuation, especially, of profiles and patterns with the lapse of time. SOLUTION: The positive photoresist composition to be used comprises (A) a resin having a protective group being insoluble in alkali but to be cleft and solubilized in it by the action of acid and (B) an acid generator and (C) a polycyclic compound represented by the formula in which X is a simple bond or a divalent bonding group; at least one of R<1> -R<10> is -OZ and each of the other groups is an H or halogen atom or a nitro or hydroxyl group and each of R<9> and R<10> may combine with each other or may be a divalent bonding group; Z is an alkyl or aryl or -COOR<11> or -SO2 R<12> group; and each of R<11> and R<12> is an alkyl or alkoxy or aryl group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoresist composition suitable for lithography or the like which is acted on by high-energy radiation such as deep ultraviolet rays (including excimer lasers), electron beams, X-rays or radiation. It is.

[0002]

2. Description of the Related Art In recent years, with the increase in the degree of integration of semiconductor integrated circuits, the formation of quarter-micron patterns has been required. In particular, lithography using an excimer laser from krypton fluoride (KrF) or argon fluoride (ArF) has attracted attention because it enables the manufacture of 64 MDRAM and 256 MDRAM. As a resist suitable for such an excimer laser lithography process, a so-called chemically amplified resist utilizing a chemical amplification effect by an acid catalyst has been proposed. The chemically amplified resist develops solubility in an alkali developing solution in an exposed part by a reaction using an acid generated from an acid generator in a radiation irradiation part as a catalyst, whereby a positive photoresist is obtained.

[0003]

In a chemically amplified resist, an acid generated in a radiation-irradiated portion is subjected to a subsequent heat treatment (po).
Although it is diffused by stexposure bake (hereinafter abbreviated as PEB), the protecting group of the resin or the like is eliminated, and the acid is regenerated, high sensitivity is realized, but further higher sensitivity is desired. In addition, improvement in resolution is also desired. Further, in such a chemically amplified resist, an acid generated by irradiation may cause the deprotection group reaction of the resin to gradually progress during the period from irradiation to PEB. Due to such a phenomenon, the profile is deteriorated, the resolution is reduced, and the pattern after development is thinned, so that the dimensional reproducibility is impaired. Further, there is also a problem that the acid is deactivated due to amines or the like existing in a small amount in the air during the period from the irradiation to the PEB, and this may cause a reduction in resolution and a reduction in dimensional reproducibility.

An object of the present invention is to provide excellent performance such as sensitivity, resolution, heat resistance, residual film ratio, and coatability, and in particular, to excel in the profile and the dimensional change resistance of the pattern over time due to the standing time from irradiation to PEB. Another object of the present invention is to provide a chemically amplified positive photoresist composition.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a positive type photoresist composition having excellent performance can be obtained by combining specific components. completed.

That is, the present invention provides a positive photoresist composition containing the following components.

(A) a resin which is itself insoluble or hardly soluble in alkali, but has a protecting group which can be cleaved by the action of an acid and becomes alkali-soluble after cleavage, (B) an acid generator, and C) A polycyclic compound represented by the following formula (I):

[0008]

Wherein X is a direct bond or carbon, nitrogen,
Represents a divalent linking group having an atom selected from oxygen and sulfur as a constituent atom, and at least one of R ¹ to R ¹⁰ represents —O
Z represents Z, wherein Z is an optionally substituted alkyl, aryl,

[0010]

Wherein R ¹¹ and R ¹² represent alkyl which may have a substituent, alkoxy or aryl which may have a substituent, and the rest of R ¹ to R ¹⁰ represent Independently represents hydrogen, an optionally substituted alkyl, halogen, nitro or hydroxyl group,
Alternatively, R ⁹ and R ¹⁰ together form a direct bond or a divalent linking group having an atom selected from carbon, nitrogen, oxygen and sulfur as a constituent atom.

The inclusion of the polycyclic compound represented by the above formula (I) improves the dimensional variation resistance of the profile and the pattern over time.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. Resin (A) as the main component of the photoresist composition
Has a protective group which can be cleaved by the action of an acid and is insoluble or hardly soluble in alkali by itself, but becomes alkali-soluble after the protective group is cleaved by the action of an acid. For example, a resin is used in which at least a part of the phenolic hydroxyl group of the alkali-soluble resin having a phenol skeleton is protected by an acid-labile group having the ability to inhibit dissolution in an alkali developer.

Examples of the base alkali-soluble resin include novolak resin, polyvinyl phenol resin, polyisopropenyl phenol resin, vinyl phenol and styrene, acrylonitrile, a copolymer of methyl methacrylate or methyl acrylate, and isopropenyl phenol and styrene. , Acrylonitrile, copolymers with methyl methacrylate or methyl acrylate, and the like. The positional relationship between the hydroxyl group and the vinyl or isopropenyl group in vinylphenol and isopropenylphenol is not particularly limited, but p-vinylphenol and p-isopropenylphenol are generally preferred. These resins may be hydrogenated to improve transparency. In addition, an alkyl group, an alkoxy group, or the like may be introduced into the phenol nucleus of the resin as long as it is soluble in alkali. Among these alkali-soluble resins, a polyvinylphenol resin, that is, a homopolymer of vinylphenol or a copolymer of vinylphenol and another monomer is preferably used.

The group which is introduced into the alkali-soluble resin and has the ability to inhibit dissolution in an alkali developer but is unstable to an acid can be any of various known protecting groups. For example, tert-butoxycarbonyl, tert-butoxycarbonylmethyl, tetrahydro-2-pyranyl, tetrahydro-2-furyl, methoxymethyl, 1-ethoxyethyl, and the like, and these groups are substituted with hydrogen of a phenolic hydroxyl group. become. Among these protecting groups,
In the present invention, 1-alkoxyalkyl, particularly 1-ethoxyethyl, is particularly preferred. When these protecting groups are introduced into the phenolic hydroxyl groups of an alkali-soluble resin having a phenol skeleton, the proportion of the phenolic hydroxyl groups in the alkali-soluble resin that are substituted with a protecting group (protection group introduction rate) is generally Preferably it is in the range of 10 to 50%.

In the present invention, in particular, the phenolic hydroxyl group of the above-mentioned polyvinylphenol-based resin has a dissolution inhibiting ability in an alkali developing solution and does not react with an acid as all or a part of the resin (A). It is preferred to use those which are partially protected by stable groups. Of these, a resin in which the phenolic hydroxyl group of a polyvinylphenol-based resin is partially protected by 1-alkoxyalkyl, especially 1-ethoxyethyl, is preferred.

The acid generator (B) constituting the photoresist composition may be various compounds that generate an acid by irradiating the substance itself or a resist composition containing the substance with radiation. It can, of course, also be used as a mixture of two or more compounds. For example, an onium salt, an organic halogen compound, a compound having a diazomethane disulfonyl skeleton, an orthoquinonediazide compound, a sulfonic acid compound, and the like can be given. In the present invention, a compound having a diazomethane disulfonyl skeleton is preferably used as the acid generator.

In addition to the above resin (A) and acid generator (B), the photoresist composition of the present invention contains a polycyclic compound (C) represented by the above formula (I).

In the formula (I), at least one of R ¹ to R ¹⁰ represents —OZ, wherein Z is an optionally substituted alkyl, aryl, —COR ¹¹ or —COR ^11. SO ₂ R ¹² , wherein R ¹¹ and R ¹² are an alkyl which may have a substituent, an alkoxy or an aryl which may have a substituent. Examples of the group which may be substituted with the alkyl or alkoxy herein include:
Examples thereof include halogen such as fluorine, chlorine, bromine and iodine, lower alkoxy having about 1 to 6 carbon atoms, lower alkoxycarbonyl having about 1 to 6 carbon atoms in the alkyl portion, and aryl such as phenyl and alkylphenyl.

As the alkyl in the above meaning constituting Z, for example, methyl, ethyl, 1-ethoxyethyl,
2-methoxyethyl, 2-ethoxyethyl, etc. tert- butoxycarbonyl methyl. Examples of the aryl include phenyl, 4-methylphenyl, and examples of the group represented by -COR ^11, for example, Alkylcarbonyl such as acetyl and tert-butoxymethylcarbonyl, arylcarbonyl such as benzoyl and p-methylbenzoyl, and methoxycarbonyl and
alkoxycarbonyl, such as tert- butoxycarbonyl. Examples of the group represented by -SO ₂ R ^12, for example, methanesulfonyl and ethanesulfonyl, alkylsulfonyl such as n- hexane, benzenesulfonyl or p- toluenesulfonic And arylsulfonyl such as sulfonyl. Among them, Z is preferably 1-ethoxyethyl, tert-butoxycarbonylmethyl or tert-butoxycarbonyl.

At least one of R ¹ to R ¹⁰ is the above-mentioned —OZ, and the rest are, independently of one another, hydrogen, optionally substituted alkyl, halogen, nitro or hydroxyl, or R ⁹ and R ¹⁰ form a direct bond or a divalent linking group whose constituent atoms are atoms selected from carbon, nitrogen, oxygen and sulfur. The alkyl here may have, for example, about 1 to 6 carbon atoms, and may be unsubstituted or substituted. Examples of the alkyl substituent include halogens such as fluorine, chlorine, bromine and iodine, lower alkoxy having about 1 to 6 carbon atoms and aryl, for example, unsubstituted or lower alkyl having about 1 to 6 carbon atoms and carbon atoms. Examples thereof include phenyl substituted with about 1 to 6 lower alkoxy, halogen, nitro or acetylamino. Preferred alkyls are methyl, ethyl and the like.

X in the formula (I) is a direct bond or a divalent linking group having at least one of carbon, nitrogen, oxygen and sulfur as a constituent atom. Also, as mentioned above,
R ⁹ and R ¹⁰ may be taken together to form a direct bond or a divalent linking group having at least one of carbon, nitrogen, oxygen and sulfur as a constituent atom. When X is a divalent linking group, or when R ⁹ and R ¹⁰ form a divalent linking group, these linking groups are formed by linking an atom other than carbon, nitrogen, oxygen and sulfur, such as hydrogen. Including
Of course you can. Specific examples of such a divalent linking group include:

[0023]

--O--, --S--, --SO--, --SO _2- and the like, wherein R ¹³ , R ¹⁴ and R ¹⁵ may each independently have hydrogen or a substituent. Represents alkyl.

Among the above, preferred as X are:
Direct bond, -CO-, -COO-, -O-, -S-,-
SO -, - SO ₂ - and the like. Preferred divalent groups formed by the combination of R ⁹ and R ¹⁰ include —CO— and —.
NR ¹³ —, —CR ¹⁴ R ¹⁵ —, —O—, —S— and the like, wherein R ¹³ , R ¹⁴ and R ¹⁵ represent the same meaning as above.

The alkyl represented by R ¹³ , R ¹⁴ and / or R ¹⁵ may have, for example, about 1 to 6 carbon atoms, and may be unsubstituted or substituted. Examples of the alkyl substituent include halogens such as fluorine, chlorine, bromine and iodine, lower alkoxy having about 1 to 6 carbon atoms and aryl, for example, unsubstituted or lower alkyl having about 1 to 6 carbon atoms and carbon atoms. Examples thereof include phenyl substituted with about 1 to 6 lower alkoxy, halogen, nitro or acetylamino. Preferred alkyls are methyl, ethyl, 1-ethoxyethyl and the like.

The polycyclic compound represented by the formula (I) can be obtained by protecting a polycyclic compound wherein —OZ in the formula is a hydroxyl group by a known method. In the formula (I), when X is —NH— and / or when R ⁹ and R ¹⁰ are bonded to form a divalent linking group —NH—, the hydrogen at the N-position is also May be protected.

Examples of the compound which is a raw material of the polycyclic compound of the formula (I) and in which —OZ is a hydroxyl group include, for example,
Examples include the following:

3- or 4-hydroxybiphenyl,
Hydroxybiphenyls such as 4,4'-dihydroxybiphenyl; 4-hydroxybenzophenone, 2,
Hydroxybenzophenones such as 2'-, 4,4'- or 2,4-dihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone; benzoic acid 3-
Or 4-hydroxyphenyl, 3,5-dihydroxyphenyl benzoate, phenyl 4-hydroxybenzoate,
Hydroxy-substituted phenyls such as 4'-methoxyphenyl 4-hydroxybenzoate; 2- or 3-
Hydroxycarbazoles such as hydroxycarbazole; hydroxyanthraquinones such as 2-hydroxyanthraquinone, 2,6-dihydroxyanthraquinone, alizarin, purpurin, quinizarin; hydroxyfluorenes such as 2- or 4-hydroxyfluorene; Hydroxyfluorenones such as 3- or 4-hydroxyfluorenone; hydroxyacridones such as 2-hydroxyacridone; hydroxyxanthones such as 2-hydroxyxanthone;
Hydroxythioxanthones such as hydroxyxityantone.

Although the resist composition of the present invention is insoluble or hardly soluble in alkali as described above,
It contains a resin (A), an acid generator (B) and a polycyclic compound (C) which have a protecting group which can be cleaved by the action of an acid and become alkali-soluble after cleavage. , An electron donor, a dissolution inhibitor, a sensitizer, a dye, an adhesion improver, a basic substance, and the like. Basic substances are generally added to chemically amplified positive photoresists in order to suppress performance degradation due to acid deactivation due to leaving from irradiation to PEB, and various types of amines are used. There can be.

The preferred composition ratio of the positive photoresist composition is such that the resin (A) is in the range of 20 to 98% by weight and the acid generator (B) is 0.2% by weight, based on the total solid content in the composition. In the range of 0.5 to 20% by weight, the content of polycyclic compound (C) is 0.01
In the range of 10 to 10% by weight. When a basic substance is used, 0.001 to 1 based on the total weight of solids in the composition.
Preferably it is present in the range of 0% by weight.

The positive photoresist composition is usually
The above components are mixed with a solvent to prepare a resist solution so that the total solid content concentration is 10 to 50% by weight, and the resist solution is applied onto a substrate such as a silicon wafer. The solvent used here may be any solvent that dissolves each component, and may be a solvent generally used in this field. For example, glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate, propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate, ethyl cellosolve, methyl cellosolve, propylene glycol monomethyl ether, propylene glycol monoethyl ether and diethylene glycol dimethyl ether. Such as glycol mono- or diethers, esters such as ethyl lactate, butyl acetate and ethyl pyruvate, ketones such as 2-heptanone, cyclohexanone and methyl isobutyl ketone, and aromatic hydrocarbons such as xylene. Can be These solvents are
Each can be used alone or in combination of two or more.

Thereafter, a positive pattern is formed from the resist film applied on the substrate through the steps of prebaking, patterning exposure, PEB, and development with an alkali developing solution.

[0034]

EXAMPLES Next, examples of the present invention will be described, but the present invention is not limited by these examples. In the examples, percentages and parts representing contents or amounts used are by weight unless otherwise specified.

Reference Example (Protection of Resin) A weight-average molecular weight (M
w) 23,900, poly (p) with a polydispersity index (Mw / Mn) of 1.12
-Vinylphenol) ["VP-1500" manufactured by Nippon Soda Co., Ltd.
0 "] 25 parts and p-toluenesulfonic acid 0.021
And 250 parts of 1,4-dioxane was added and dissolved. To this solution, 7.9 parts of ethyl vinyl ether was added dropwise and then reacted at 25 ° C. for 5 hours. The solution after the reaction was dropped into 1,500 parts of ion-exchanged water, and then separated by filtration.
A white wet cake was obtained. This wet cake,
It was again dissolved in 200 parts of 1,4-dioxane, then dropped into 1,500 parts of ion-exchanged water, and filtered. The obtained wet cake was taken out, and the washing operation with ion-exchanged water was further repeated twice. The obtained white wet cake was dried under reduced pressure to obtain a resin in which hydroxyl groups of poly (p-vinylphenol) were partially 1-ethoxyethyl etherified. When this resin was analyzed by proton nuclear magnetic resonance,
About 35 mol% of the hydroxyl groups were protected with 1-ethoxyethyl groups. This resin had a weight average molecular weight of 31,200 and a polydispersity of 1.17.

Synthesis Example 1 (Ethoxyethylation of 3-hydroxybiphenyl) A 4-neck flask was charged with 5.0 parts of 3-hydroxybiphenyl and 0.007 parts of p-toluenesulfonic acid.
65 parts of 4-dioxane was added and dissolved. To this solution, 3.2 parts of ethyl vinyl ether was added dropwise, and then at room temperature for 1 hour.
The reaction was performed for 5 hours. After the completion of the reaction, this slurry was charged into a flask with a bottom, 100 parts of ethyl acetate and 50 parts of toluene were added, and then washed five times with 200 parts of distilled water. The organic layer was concentrated, and the obtained oil was subjected to column chromatography (silica gel, n-hexane: ethyl acetate =
After purifying according to 9: 1), the residue was dried under reduced pressure to obtain 3- (1-ethoxyethoxy) biphenyl. This is compound C-1
And

Mass spectrometry (FD-MS): 242 (M ⁺ ) ¹ H-NMR (dimethyl sulfoxide) δ (ppm): 1.0
9-1.14 (t, 3H); 1.41-1.44 (d, 3H); 3.46-3.76 (m, 2
H); 5.54-5.60 (q, 1H); 6.98-7.03 (m, 1H); 7.25-7.29
(m, 2H); 7.31-7.41 (m, 2H); 7.44-7.49 (m, 2H); 7.63
-7.67 (m, 2H).

Synthesis Example 2 (Ethoxyethylation of 4-hydroxybiphenyl) In place of 3-hydroxybiphenyl in Synthesis Example 1,
Using 10.0 parts of 4-hydroxybiphenyl, and further adding p-
The same operation as in Synthesis Example 1 was performed, except that the amount of toluenesulfonic acid was changed to 0.015 part, the amount of 1,4-dioxane was changed to 130 parts, and the amount of ethyl vinyl ether was changed to 6.4 parts. As a result, 4- (1-ethoxyethoxy) biphenyl was obtained. This is designated as compound C-2.

Mass spectrometry (FD-MS): 242 (M ⁺ ) ¹ H-NMR (dimethyl sulfoxide) δ (ppm): 1.0
9-1.14 (t, 3H); 1.41-1.43 (d, 3H); 3.46-3.76 (m, 2
H); 5.48-5.54 (q, 1H); 7.06-7.11 (d, 2H); 7.28-7.35
(t, 1H); 7.41-7.47 (t, 2H); 7.57-7.63 (m, 4H).

Synthesis Example 3 (Ethoxyethylation of 4,4'-dihydroxybiphenyl) In place of 3-hydroxybiphenyl in Synthesis Example 1,
Using 8.0 parts of 4,4'-dihydroxybiphenyl, further adding 0.02 parts of p-toluenesulfonic acid, 1,4-
The same operation as in Synthesis Example 1 was carried out except that the amount of dioxane was changed to 140 parts and the amount of ethyl vinyl ether was changed to 9.3 parts. As a result, 4,4'-di (1-ethoxyethoxy) biphenyl was obtained. This is designated as compound C-3.

Mass spectrometry (FD-MS): 330 (M ⁺ ) ¹ H-NMR (dimethyl sulfoxide) δ (ppm): 1.0
9-1.14 (t, 6H); 1.40-1.42 (d, 6H); 3.45-3.77 (m, 4
H); 5.46-5.51 (q, 2H); 7.04-7.07 (d, 4H); 7.51-7.56
(d, 4H).

Synthesis Example 4 (Ethoxyethylation of 2-hydroxycarbazole) 13.2 2-hydroxycarbazole was placed in a four-necked flask.
Parts, pyridine 1.0 parts and p-toluenesulfonic acid 2.4 parts
Were added and 210 parts of 1,4-dioxane was added and dissolved. To this solution, 15.5 parts of ethyl vinyl ether was added dropwise, followed by reaction at 25 ° C. for 20 hours. After the completion of the reaction, this slurry was charged into a bottomed flask, 100 parts of ethyl acetate and 400 parts of toluene were added, and the mixture was washed five times with 200 parts of distilled water. The organic layer was concentrated, hexane was added thereto, and the mixture was stirred and filtered, and the filtrate was dried under reduced pressure all day and night to obtain 15.9 parts of a solid. As a result of composition analysis by liquid chromatography, 35% of the di-substituted product and 3% of the mono-substituted product were determined by chromatogram area percentage.
The mixture contained 3%. This is designated as compound C-4.

After the compound was developed by thin-layer liquid chromatography, the separated components were scraped off and the structures were analyzed. The structures of the mono-substituted product and the di-substituted product were as follows.

[0044]

Monosubstituted mass spectrometry (FD-MS): 255 (M ⁺ ) ¹ H-NMR (chloroform) δ (ppm): 1.10 (t, 3)
H); 1.69 (d, 3H); 3.25-3.39 (m, 2H); 4.91 (s, 1H);
5.84 (q, 1H); 6.68-6.70 (d, 1H); 7.04-7.06 (d, 1H);
7.12-7.15 (t, 1H); 7.27-7.31 (t, 1H); 7.47-7.50
(d, 1H); 7.82-7.85 (d, 1H); 7.89-7.91 (d, 1H).

Disubstituted mass spectrometry (FD-MS): 327 (M ⁺ )

Synthesis Example 5 (2-hydroxycarbazole
tert-butoxycarbonylation) A four-necked flask was charged with 5.0 parts of 2-hydroxycarbazole and 6.6 parts of di-tert-butyl dicarbonate.
-90 parts of dioxane was added and dissolved. To this solution, 7.3 parts of triethylamine was added dropwise and then reacted at 60 ° C. for 4 hours. After the completion of the reaction, this slurry was charged into a bottomed flask, and 150 parts of ethyl acetate and 150 parts of toluene were added.
Were added and then washed eight times with 200 parts of distilled water. The organic layer was concentrated, 150 parts of toluene and 50 parts of hexane were added to the concentrated mass, the mixture was cooled to 20 ° C., filtered, and washed with 200 parts of hexane. The obtained filtrate was dried under reduced pressure at 45 ° C for 24 hours to obtain 2- (tert-butoxycarbonyloxy) carbazole. This is designated as compound C-5.

Mass spectrometry (SIMS (FAB)): 283
(M ⁺ ) ¹ H-NMR (dimethyl sulfoxide) δ (ppm): 1.5
2 (s, 9H); 6.94-6.98 (d, 1H); 7.14-7.20 (t, 1H); 7.
29-7.30 (d, 1H); 7.35-7.41 (t, 1H); 7.48-7.52 (d, 1
H); 8.09-8.12 (d, 2H); 11.35 (s, 1H).

Synthesis Example 6 (of 2-hydroxycarbazole
tert-butoxycarbonylmethylation) In a four-necked flask, 2-hydroxycarbazole 5.0
Parts, 8.3 parts of potassium carbonate and 2.0 parts of potassium iodide, and 70 parts of 1,4-dioxane was added and dissolved. To this solution, 9.0 parts of tert-butyl chloroacetate was added dropwise, followed by reaction at 100 ° C. for 24 hours. After the completion of the reaction, this slurry was charged into a bottomed flask, 150 parts of ethyl acetate and 50 parts of toluene were added, and then 2 parts of distilled water was added.
Washed 6 times with 00 parts. The organic layer was concentrated, and 150 parts of toluene and 50 parts of hexane were added to the concentrated mass to give 20 parts.
After cooling to ℃, filtered and washed with 200 parts of hexane.
The obtained filtrate was dried under reduced pressure at 45 ° C for 24 hours,
(Tert-Butoxycarbonylmethoxy) carbazole was obtained. This is designated as compound C-6.

Mass spectrometry (FD-MS): 297 (M ⁺ ) ¹ H-NMR (dimethyl sulfoxide) δ (ppm): 1.4
5 (s, 9H); 4.72 (s, 2H); 6.75-6.79 (d, 1H); 6.90-6.
91 (d, 1H); 7.08-7.14 (t, 1H); 7.26-7.32 (t, 1H);
7.41-7.43 (d, 1H); 7.96-8.00 (t, 2H); 11.14 (s, 1
H).

Synthesis Example 7 (Ethoxyethylation of 2-hydroxyfluorenone) In place of 3-hydroxybiphenyl in Synthesis Example 1,
Using 3.2 parts of 2-hydroxyfluorenone, p-
The same operation as in Synthesis Example 1 was performed except that the amount of toluenesulfonic acid was 0.004 parts, the amount of 1,4-dioxane was 40 parts, and the amount of ethyl vinyl ether was 1.8 parts.
As a result, 2- (1-ethoxyethoxy) fluorenone was obtained. This is designated as compound C-7.

Mass spectrometry (FD-MS): 268 (M ⁺ ) ¹ H-NMR (dimethyl sulfoxide) δ (ppm): 1.0
9-1.14 (t, 3H); 1.41-1.43 (d, 3H); 3.46-3.75 (m, 2
H); 5.55-5.61 (q, 1H); 7.17-7.22 (m, 2H); 7.27-7.32
(t, 1H); 7.54-7.60 (m, 2H); 7.69-7.73 (d, 2H).

Synthesis Example 8 (Ethoxyethylation of 4,4'-dihydroxybenzophenone) In place of 3-hydroxybiphenyl in Synthesis Example 1,
Using 5.4 parts of 4,4'-dihydroxybenzophenone,
Further, the amount of p-toluenesulfonic acid was 0.02 parts,
The same operation as in Synthesis Example 1 was carried out except that the amount of 4-dioxane was changed to 90 parts and the amount of ethyl vinyl ether was changed to 7.4 parts. As a result, 4,4'-di (1-ethoxyethoxy) benzophenone was obtained. This is designated as compound C-8.

Mass spectrometry (SIMS (FAB)): 359
(M + 1 ⁺ ) ¹ H-NMR (dimethyl sulfoxide) δ (ppm): 1.0
9-1.15 (t, 6H); 1.44-1.46 (d, 6H); 3.47-3.75 (m, 4
H); 5.61-5.67 (q, 2H); 7.12-7.15 (d, 4H); 7.69-7.72
(d, 4H).

Synthesis Example 9 (Ethoxyethylation of 2,4-dihydroxybenzophenone) In place of 3-hydroxybiphenyl in Synthesis Example 1,
Using 5.4 parts of 2,4-dihydroxybenzophenone,
Further, the amount of p-toluenesulfonic acid was 0.006 parts,
The same operation as in Synthesis Example 1 was carried out except that the amount of 4-dioxane was changed to 90 parts and the amount of ethyl vinyl ether was changed to 7.4 parts. As a result, 4- (1-ethoxyethoxy)-
2-Hydroxybenzophenone was obtained. Compound C
−9.

Mass spectrometry (FD-MS): 286 (M ⁺ ) ¹ H-NMR (dimethyl sulfoxide) δ (ppm): 1.1
0-1.15 (t, 3H); 1.43-1.44 (d, 3H); 3.46-3.74 (m, 2
H); 5.61-5.67 (q, 1H); 6.56-6.60 (d, 1H); 6.63-6.64
(d, 1H); 7.41-7.44 (d, 1H); 7.51-7.57 (m, 2H); 7.61
-7.68 (m, 3H); 11.84 (s, 1H).

Synthesis Example 10 (Ethoxyethylation of 2,2'-dihydroxybenzophenone) In place of 3-hydroxybiphenyl in Synthesis Example 1,
Using 4.9 parts of 2,2'-dihydroxybenzophenone,
Further, the amount of p-toluenesulfonic acid was 0.055 parts,
The same operation as in Synthesis Example 1 was performed, except that the amount of 4-dioxane was changed to 85 parts and the amount of ethyl vinyl ether was changed to 6.8 parts. As a result, 2- (1-ethoxyethoxy)-
2'-Hydroxybenzophenone was obtained. This is designated as compound C-10.

Mass spectrometry (SIMS (FAB)): 287
(M + 1 ⁺ ) ¹ H-NMR (dimethyl sulfoxide) δ (ppm): 0.9
7-1.02 (t, 3H); 1.18-1.20 (d, 3H); 3.31-3.53 (m, 2
H); 5.42-5.48 (q, 1H); 6.87-6.93 (t, 1H); 6.99-7.03
(d, 1H); 7.10-7.16 (t, 1H); 7.24-7.30 (t, 2H); 7.36
-7.39 (d, 1H); 7.48-7.57 (m, 2H); 11.57 (s, 1H).

Synthesis Example 11 (Ethoxyethylation of 2,3,4-trihydroxybenzophenone) In place of 2-hydroxycarbazole in Synthesis Example 4, 2,3,4-trihydroxybenzophenone 11.5
Parts, and the amount of p-toluenesulfonic acid was further increased to 5.1.
The same operation as in Synthesis Example 4 was performed except that the amount of pyridine was 2.1 parts, the amount of 1,4-dioxane was 285 parts, and the amount of ethyl vinyl ether was 33.1 parts. As a result, ethoxyethylated 2,3,4-trihydroxybenzophenone was obtained. As a result of composition analysis by liquid chromatography, the mixture was found to be a mixture containing 70% of the di-substituted product and 19% of the mono-substituted product by chromatogram area ratio.
This is designated as compound C-11.

Mass spectrometry (SIMS (FAB)): 303 (mono-substituted: M + 1 ⁺ ), 375 (di-substituted:
M + 1 ⁺ ).

Synthesis Example 12 (Ethoxyethylation of 2,3,4,4'-tetrahydroxybenzophenone) In place of 2-hydroxycarbazole in Synthesis Example 4, 2,3,4,4'-tetrahydroxybenzophenone Using 3 parts, add 6.9 parts of p-toluenesulfonic acid, 2.8 parts of pyridine, 260 parts of 1,4-dioxane and 4 parts of ethyl vinyl ether.
The same operation as in Synthesis Example 4 was performed except that 4.1 parts were used.
As a result, an ethoxyethylated 2,3,4,4'-tetrahydroxybenzophenone was obtained. As a result of composition analysis by liquid chromatography, a mixture containing 57% of the tri-substituted product and 30% of the di-substituted product was found to be a chromatogram area ratio. This is designated as compound C-12.

Mass spectrometry (SIMS (FAB)): 391 (disubstituted: M + 1 ⁺ ), 463 (trisubstituted:
M + 1 ⁺ ).

Examples 1 to 12 13.5 parts of a polymer obtained by the reference example and having about 35 mol% of the hydroxyl groups in poly (p-vinylphenol) 1-ethoxyethyl etherified, and bis as an acid generator 0.5 parts of (cyclohexanesulfonyl) diazomethane,
Compounds C-1 to C-12 obtained in Synthesis Examples 1 to 12 were used in the amounts shown in Table 1 and 0.015 parts of N-phenyldiethanolamine as a basic substance, and these were used in propylene glycol monomethyl ether acetate 68.
The mixture was dissolved in the mixture and filtered through a fluororesin filter having a pore size of 0.2 μm to obtain a resist solution.

The above-mentioned resist solution was spin-coated on a silicon wafer cleaned by a conventional method using a spin coater to form a resist film having a thickness of 0.717 μm after drying.
Next, this silicon wafer is placed on a hot plate for 9 hours.
Prebaked at 0 ° C for 90 seconds. The coating film after pre-baking was passed through a chrome mask having a pattern at 248 nm.
Exposure was performed using a KrF excimer laser stepper (Nikon Corporation, "NSR-1755 EX8A", NA = 0.45) having the following exposure wavelength. The exposed wafer was heated on a hot plate at 100 ° C. for 90 seconds. This was developed with a 2.38% aqueous solution of tetramethylammonium hydroxide to obtain a positive pattern. Each positive pattern was evaluated as follows, and the results are shown in Table 1.

Sensitivity: A section of a 0.3 μm line and space pattern was observed with a scanning electron microscope, and the line and space pattern in the best focus was 1: 1.
The exposure amount (effective sensitivity) was as follows.

Resolution: The minimum line-and-space width at which the film was separated without reducing the film thickness at the effective exposure dose was measured with a scanning electron microscope.

Thin dimensions: 0.3 μm line-and-space pattern obtained by performing PEB immediately after exposure at the effective sensitivity exposure amount, and 30 minutes after exposure at the same exposure amount, followed by PEB The cross-sectional shape of the obtained 0.3 μm line and space pattern was observed with a scanning electron microscope, and the dimensional difference between the former and the latter patterns was measured.

Profile: The cross-sectional shape of the 0.3 μm line-and-space pattern at the exposure amount of the effective sensitivity was observed with a scanning electron microscope and evaluated according to the following criteria. The pattern of each example is cut almost vertically,
The flat part of the pattern top was also clearly observed.

The pattern is cut almost vertically, and the flat portion of the pattern top is clearly observed: ○ The pattern top is round: ×

COMPARATIVE EXAMPLE In place of Compounds C-1 to C-12 obtained in Synthesis Examples 1 to 12, 0.35 parts of 3-hydroxybiphenyl (denoted as Compound X in Table 1) was used. The same operation as in Examples 1 to 12 was performed. The results are shown in Table 1. The resist of the comparative example was 0.23 μm at an exposure of 60 mJ / cm ^2.
Pattern was resolved, but the narrow dimension was 0.03μ.
m, and the cross-sectional shape (profile) was insufficient because the pattern top was round.

[0071]

TABLE 1 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Example No. Compound (C) re g preparative performance type amount Sensitivity Resolution Thin dimensions Profile (parts) (mJ / cm ² ) (μm) (μm) ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Example 1 C-1 0.35 51 0.23 0.01 ○ 〃 2 C-2 0.36 49 0.23 0.00 ○ ３ 3 C-3 0.35 56 0.23 0.00 ○ 〃 4 C-4 0.20 70 0.22 0.00 ○ 〃 5 C-5 0.20 60 0.22 0.00 ○ 〃 6 C-6 0.20 67 0.22 0.00 ○ ７ 7 C-7 0.20 81 0.22 0.00 ○ ８ 8 C-8 0.30 78 0.23 0.01 ○ 〃 9 C-9 0.30 86.5 0.24 0.00 ○ 〃 10 C-10 0.30 76 0.24 0.00 ○ 〃 11 C-11 0.30 85 0.23 0.01 ○ 〃 12 C-12 0.30 80 0.23 0.01 ○ ───────────────────────────── Comparative example X 0.35 60 0.23 0.03 × ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[0072]

According to the present invention, the photoresist composition to which the polycyclic compound represented by the above formula (I) is added can maintain various properties such as heat resistance, remaining film ratio, coatability and the like at a high level. It has excellent sensitivity, resolution and profile, and suppresses dimensional fluctuation of the pattern.

Claims (7)

[Claims] (A) a resin which is itself insoluble or hardly soluble in alkali, but has a protecting group which can be cleaved by the action of an acid and becomes alkali-soluble after cleavage; (B) an acid generator; (C) the following formula (I) (Wherein, X represents a direct bond or a divalent linking group having an atom selected from carbon, nitrogen, oxygen and sulfur as a constituent atom, and at least one of R ¹ to R ¹⁰ represents —OZ;
Here, Z represents an optionally substituted alkyl, aryl, —COR ¹¹ or —SO ₂ R ¹² , wherein R
¹¹ and R ¹² are alkyl optionally having substituent (s),
Represents an optionally substituted alkoxy or aryl, and the rest of R ¹ to R ¹⁰ independently of one another represent a hydrogen, an optionally substituted alkyl, halogen, nitro or hydroxyl group, or And R ⁹ and R ¹⁰ together form a direct bond or a polycyclic compound represented by the following formula: which forms a divalent linking group having atoms selected from carbon, nitrogen, oxygen and sulfur). A positive photoresist composition comprising: 2. The resin (A) having a protective group cleavable by the action of an acid is a polyvinylphenol-based resin,
The composition of claim 1, wherein the phenolic hydroxyl group is partially protected with 1-ethoxyethyl. 3. The composition according to claim 1, wherein the acid generator (B) is a compound having a diazomethane disulfonyl skeleton. 4. X in the formula (I) is a direct bond, —CO—,
-COO -, - O -, - S -, - SO- or -SO ₂
The composition according to any one of claims 1 to 3, wherein 5. At least one of R ¹ to R ^{8 in} the formula (I) is —OZ, wherein Z has the meaning defined in claim 1, and the rest of R ¹ to R ⁸ are independent of each other. , Hydrogen,
An optionally substituted alkyl, halogen, nitro or hydroxyl group, and R ⁹ and R ^{10 taken} together as a direct bond or an atom selected from carbon, nitrogen, oxygen and sulfur as a constituent atom The composition according to any one of claims 1 to 4, which forms a divalent linking group. 6. A direct bond between R ⁹ and R ¹⁰ , -CO-,-
Forming NR ¹³ , —CR ¹⁴ R ¹⁵ —, —O— or —S—, wherein R ¹³ , R ¹⁴ and R ¹⁵ independently of one another are hydrogen or optionally substituted alkyl A composition according to claim 5. 7. The composition according to claim 1, wherein Z is 1-ethoxyethyl, tert-butoxycarbonyl or tert-butoxycarbonylmethyl.