JPH09136871A - Quinonediazidosulfonic ester and use thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a compound useful as a photosensitizer in positive-type resist compositions. SOLUTION: This new compound of formula I (Q<1> , Q<2> and Q<3> are such that one of them is o-quinonediazidosulfonyl, the other being each H or o- quinonediazidosulfonyl) is useful as an active ingredient for photosensitizers. This compound is mixed with an alkali-soluble novolak resin (a condensate from a phenolic compound and an aldehyde) to give a positive-type resist composition which is excellent in balance among photosensitivity, resolution, γ-value and profile, etc., producing no scum in developing operation, and effective for the fine processing of semiconclucttors. This compound of formula I is obtained by reaction of 1,3-dihydroxy-4-(4-hyclroxy-2,3,6-trimethylbenzyl)-2-methylbenzene of formula II with an o-quinonediazidosulfonic halide in the presence of a base.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a quinonediazide sulfonic acid ester of a polyphenol compound and its application to the resist field.

[0002]

2. Description of the Related Art Generally, a compound having a phenolic hydroxyl group is converted into a quinonediazide sulfonic acid ester, and a positive resist film is formed from a photosensitive resin composition containing the ester as a photosensitizer and used for fine processing of semiconductors. Are known, and various compounds having a phenolic hydroxyl group have been proposed. At present, integrated circuits in the semiconductor industry are becoming finer along with higher integration, and a lithography process plays an important role in such fineness.

[0003]

In order to cope with such semiconductor manufacturing which is becoming finer, there is a demand for a resist composition having higher performance. In addition, as the photosensitizer in the positive resist composition, a quinonediazide sulfonate ester of a polyhydric phenol compound having a plurality of phenolic hydroxyl groups in the molecule is usually used,
In particular, a partial ester thereof, or a mixture of a total ester and a partial ester is used. When a conventionally known polyhydric phenol compound is used for partial esterification, only a phenolic hydroxyl group at a specific site is selectively selected. It was generally difficult to esterify to. However, it is often advantageous to use a compound in which only the phenolic hydroxyl group at a specific site is selectively esterified, because the γ value increases, that is, the resolution increases.

One of the objects of the present invention is to provide a quinonediazide sulfonic acid ester which can be used as a photosensitizer in a resist composition for semiconductor microfabrication, thereby giving a high-performance resist composition.
Another object of the present invention is to provide a quinonediazide sulfonate ester in which only a phenolic hydroxyl group at a specific site is selectively esterified by using a polyhydric phenol compound having a specific structure, or all the phenolic hydroxyl groups are esterified. To do. Still another object of the present invention is to provide a positive resist composition excellent in various properties by using such a quinonediazide sulfonic acid ester.

[0005]

Means for Solving the Problems As a result of intensive studies aimed at achieving such an object, the present inventors have found that a polyhydric phenol compound having a specific structure is converted into an o-quinonediazide sulfonic acid ester, which is a positive type. The present invention has been completed by finding that it gives excellent results when used as a photosensitizer of a resist composition. When this polyhydric phenol compound is reacted with o-quinonediazide sulfonyl halide at a certain molar ratio, only the phenolic hydroxyl group at a specific site is selectively esterified and reacted at another molar ratio. It was also found that all of the phenolic hydroxyl groups were esterified, and each of them had excellent performance as a photosensitizer for a positive resist composition.

That is, the present invention provides a compound represented by the following formula (I).

[0007]

In the formula, ^one of Q ¹ , Q ² and Q ³ represents o-quinonediazidesulfonyl, the rest independently of each other,
Represents hydrogen or o-quinonediazidesulfonyl.

The present invention also provides a photosensitizer containing a compound represented by the formula (I) as an active ingredient, and further provides a positive resist composition containing the photosensitizer and an alkali-soluble novolak resin. .

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the formula (I), o-quinonediazidesulfonyl represented by Q ¹ , Q ² and Q ³ is, for example, 1,2-naphthoquinonediazide-4-sulfonyl or 1,2-naphthoquinonediazide. -5-sulfonyl,
It may be 1,2-benzoquinonediazide-4-sulfonyl or the like, each of which is represented by the following formula.

[0011]

Among these, 1,2-naphthoquinonediazide-5-sulfonyl is generally used. Further, in the formula (I), a compound in which Q ¹ and Q ² are o-quinonediazidesulfonyl and Q ³ is hydrogen, and
Of importance are compounds where Q ¹ , Q ² and Q ³ are all o-quinonediazidesulfonyl.

The compound represented by the formula (I) has the following formula (II)
In the presence of a base, 1,3-dihydroxy-4- (4-hydroxy-2,3,6-trimethylbenzyl) -2-methylbenzene (hereinafter sometimes referred to as “hydroxy compound (II)”) represented by It can be produced by reacting with o-quinonediazide sulfonic acid halide under the following conditions.

[0014]

Hydroxy form (II) as a raw material for this reaction
Is, for example, 4-hydroxymethyl-2,3,5-trimethylphenol obtained by monomethylolating 2,3,5-trimethylphenol with formaldehyde,
By reacting with 2-methylresorcin, it can be easily produced in high purity. In the reaction of 2,3,5-trimethylphenol and formaldehyde,
Formaldehyde is used in a molar ratio of about 1 to 8 with respect to 2,3,5-trimethylphenol.
A monomethylol compound can be selectively produced by reacting at a relatively low temperature, for example, a temperature of 0 to 5 ° C. in the presence of a base catalyst in an amount of 1 to 2 mol times that of 3,5-trimethylphenol. .

In the reaction of 4-hydroxymethyl-2,3,5-trimethylphenol with 2-methylresorcin, 2-methylresorcin is added to 2-hydroxyresorcin in an amount of 2 to 2 with respect to 4-hydroxymethyl-2,3,5-trimethylphenol. 10
It is preferable to use it in a molar ratio of, and more preferably to use in a molar ratio of 3 to 6. This reaction is generally performed in the presence of an acid catalyst. The acid catalyst may be either an inorganic acid or an organic acid, and examples thereof include hydrochloric acid, sulfuric acid, formic acid, acetic acid, oxalic acid and p-toluenesulfonic acid. Preferably, hydrochloric acid, sulfuric acid or p-toluenesulfonic acid is
More preferably hydrochloric acid is used. The acid catalyst is used in an amount of usually 0.1 to 1 mol times, preferably 0.2 to 0.5 mol times, relative to 4-hydroxymethyl-2,3,5-trimethylphenol. The reaction is usually carried out in a solvent, preferably an aqueous solvent, and the reaction solvent, especially water, is generally in the range of 1 to 10 times by weight, preferably in the range of 1 to 10 times by weight, based on the amount of 2-methylresorcin. It is used in the range of 3 to 5 times by weight. This reaction is generally performed under atmospheric pressure, for example at a temperature of about 5-60 ° C. In carrying out the reaction, 4-hydroxymethyl-2,3,5-trimethylphenol is gradually or divided into an aqueous solution containing 2-methylresorcin and an acid catalyst, for example, from 0.2 to
It is preferable to add it over 2 hours. By such a reaction, the hydroxy form (II) is produced. For example, when water is used as the reaction solvent, the hydroxy form (II) precipitates with the progress of the reaction, so solid-liquid separation may be performed.

The hydroxy compound (II) thus obtained is
o-quinonediazide sulfonic acid halide, for example, 1,
By reacting with 2-naphthoquinonediazide-4- or -5-sulfonic acid chloride, 1,2-benzoquinonediazide-4-sulfonic acid chloride, etc., an o-quinonediazidesulfonic acid ester represented by the formula (I) can be produced. . At this time, the hydroxy form (II) and o-
By reacting a quinonediazide sulfonic acid halide in a molar ratio of about 1: 2, Q ¹ and Q ² in the formula (I) are reacted.
Becomes o-quinonediazide sulfonyl, and the ester in which Q ³ remains as hydrogen is preferentially produced. When the hydroxy compound (II) and the o-quinonediazide sulfonic acid halide are reacted at a molar ratio of about 1: 3, Q in the formula (I) can be obtained.
An ester is obtained in which ¹ , Q ² and Q ³ are all o-quinonediazidesulfonyl.

The reaction between the hydroxy compound (II) and the o-quinonediazide sulfonic acid halide is carried out in the presence of a base. Examples of the base used here include amines such as trimethylamine, triethylamine, triethanolamine, N, N-dimethylaniline, N, N-diethylaniline and pyridine, and inorganic carbonates such as sodium carbonate and sodium hydrogencarbonate. And preferably triethylamine is used. The base is usually used in a molar ratio of 1.05 to 5, preferably 1.05 to 1.2, and more preferably 1.1 to o-quinonediazide sulfonic acid halide.
Used in a molar ratio of 1.2.

This esterification reaction is usually carried out in a solvent. As the reaction solvent, 1,4-dioxane, 1,3
-Dioxane, ethers such as tetrahydrofuran, esters such as [gamma] -butyrolactone, acetone, and aliphatic ketones such as 2-heptanone. These solvents may be used alone or in combination of two or more, but especially 1,4
-Dioxane or 1,3-dioxane is preferred. The reaction solvent is usually in the range of 2 to 6 times by weight, preferably 3 to 5 times by weight, more preferably 4 to 5 times by weight, based on the total amount of the hydroxy form (II) and the o-quinonediazide sulfonic acid halide. Used in the range of.

After completion of the reaction, neutralize with an acid such as acetic acid,
After filtering the solid, the filtrate is mixed with a dilute aqueous acid solution, for example, an aqueous acetic acid solution having a concentration of about 0.1 to 2% by weight.
The target ester is precipitated. This can be filtered, washed with water and dried to give the compound of formula (I).

The compound of formula (I) thus obtained can be advantageously used as a sensitizer which is sensitive to radiation such as near or far ultraviolet rays (including excimer laser and the like). This photosensitizer exhibits excellent effects when combined with an alkali-soluble novolac resin to form a positive resist composition. In this case, Q ¹ and Q in the formula (I)
Those in which any one of ² and Q ³ is o-quinonediazidesulfonyl (monoester), those in which any two of them are o-quinonediazidesulfonyl (diester), and those in which all of them are o-quinonediazidesulfonyl It may be a mixture of two or more of (triester).

Among them, what is important as a sensitizer is that 1,2-naphthoquinonediazide-5-sulfonyl is used as Q ¹ and Q ² in the formula (I) and hydrogen is used as Q ³ .
4'-bis (6-diazo-5,6-dihydro-5-oxo-1-naphthalenesulfonyloxy) -2'-hydroxy-2,3,3 ', 6-tetramethyldiphenylmethane, and formula (I) 2 ', 4,4'-tris (6-diazo-5,6-dihydro-5-oxo-1) in which Q ¹ , Q ² and Q ³ are all 1,2-naphthoquinonediazide-5-sulfonyl -Naphthalenesulfonyloxy)
It is -2,3,3 ', 6-tetramethyldiphenylmethane.

The positive resist composition containing the compound represented by the formula (I) as a photosensitizer may further contain, as another photosensitizer, an o-quinonediazide sulfonic acid ester of an aromatic hydroxy compound. In particular, when a compound in which Q ¹ , Q ² and Q ³ in the formula (I) are all o-quinonediazidesulfonyl is used, a partial o-quinonediazidesulfonic acid ester of another aromatic polyhydroxy compound is used in combination. Is advantageous. Examples of such an optionally used o-quinonediazide sulfonic acid ester include esters obtained by reacting an aromatic hydroxy compound having at least one, preferably two or more phenolic hydroxyl groups with an o-quinonediazide sulfonic acid halide. To be Aromatic hydroxy compounds to be esterified include, for example, polyhydroxybenzophenones such as trihydroxybenzophenone, tetrahydroxybenzophenone and pentahydroxybenzophenone,
2,4,4-trimethyl-2 ', 4', 7-trihydroxyflavan, 2,4,4-trimethyl-2 ',
3 ', 4', 7,8-pentahydroxyflavan, 4
-(1 ', 2', 3 ', 4', 4'a, 9'a-hexahydro-6'-hydroxy-5'-methylspiro [cyclohexane-1,9'-xanthene] -4'a-yl)
-2-methylresorcinol, 4- (1 ', 2',
Polyhydroxyflavans such as 3 ', 4', 4'a, 9'a-hexahydro-6'-hydroxyspiro [cyclohexane-1,9'-xanthene] -4'a-yl) resorcinol and others, 2 A compound having two to six benzene rings bonded with an aliphatic hydrocarbon linking group and having two or more aromatic hydroxyl groups can be used.

Further specific photosensitizers include, for example,
Japanese Unexamined Patent Publication No. 2-32352 (= USP 5,124,228), Japanese Unexamined Patent Publication No. 2-103
Japanese Patent No. 543 (= EP-A-363,978), Japanese Patent Laid-Open No. 2-269351 (=
USP 5,290,656), JP-A-3-185447 (= USP 5,283,1)
55), JP 4-50851 A (= USP 5,188,920), JP
4-295472 publication (= EP-A-505,987), JP-A-5-323597 publication (= EP-A-570,884), JP-A-6-167805 publication (= EP-A)
-573,056) and the like.

When another photosensitizer is used together with the compound represented by the formula (I), the ratio of the two is appropriately set within a range not impairing the object of the present invention. In the present invention, the photosensitizer, including the amount of such other quinonediazide sulfonic acid ester when used, is contained in the range of 10 to 50% by weight based on the total solid content in the resist composition. Is preferred.

The alkali-soluble novolac resin constituting the positive resist composition is obtained by condensing a compound having at least one phenolic hydroxyl group and an aldehyde in the presence of an acid catalyst, and its type is The material is not particularly limited, and various materials used in the resist field can be used. Examples of the phenolic compound as a raw material of the novolac resin include o-cresol, m-cresol, p-cresol, 2,5-xylenol, 3,5-xylenol, 3,4-xylenol, 2,3,5-. Examples include trimethylphenol and 2-t-butyl-5-methylphenol. Examples of the aldehyde which is the other raw material of the novolac resin include aliphatic aldehydes such as formaldehyde, acetaldehyde and glyoxal, and aromatic aldehydes such as benzaldehyde and salicylaldehyde. In particular, formaldehyde is industrially mass-produced as an aqueous solution of about 37% by weight and is preferably used.

One or two of these phenolic compounds
The novolak resin can be obtained by condensing one or more species and one or more species of aldehydes in the presence of an acid catalyst. Examples of the acid catalyst include inorganic acids such as hydrochloric acid, sulfuric acid and phosphoric acid, oxalic acid, acetic acid, organic acids such as p-toluenesulfonic acid, and divalent metal salts such as zinc acetate. The condensation reaction can be performed according to a conventional method, for example, at a temperature in the range of 60 to 120 ° C. for about 2 to 30 hours. The reaction may be performed in a bulk or in a suitable solvent.

The obtained novolac resin is subjected to an operation such as fractionation for the purpose of reducing the development residue of the resist, and then subjected to gel permeation chromatography (GP).
In the pattern by C) (using a UV254 nm detector), the area ratio of the components having a polystyrene-equivalent molecular weight of 900 or less is 25% or less with respect to the total pattern area excluding the pattern area of the unreacted phenolic compound, and further Two
It is preferably set to 0% or less. When fractionation is carried out, the novolak resin obtained by condensation is used as a good solvent, for example, alcohols such as methanol and ethanol, ketones such as acetone and methyl ethyl ketone and methyl isobutyl ketone, and ethylene glycol ethers such as ethyl cellosolve. Ethylene glycol ether esters such as ethyl cellosolve acetate,
Dissolve in ethers such as tetrahydrofuran,
A method in which this solution is poured into water to precipitate a high molecular weight component, or a method in which this solution is mixed with a poor solvent such as pentane, hexane, or heptane to carry out liquid separation can be employed.

It is also effective to add an alkali-soluble phenolic compound having a molecular weight of 900 or less to the novolak resin which has been subjected to such a fractionation operation to increase the high molecular weight component. As the alkali-soluble phenolic compound having a molecular weight of 900 or less, a polyhydric phenol compound having at least two phenolic hydroxyl groups in the molecule is preferable, for example, JP-A-2-275955 (= EP-A-358,871) and JP-A-2. -2
Examples include those described in Japanese Patent No. 560. Molecular weight 90
When an alkali-soluble phenolic compound of 0 or less is used as an additive, it is preferably contained in the range of 3 to 40% by weight based on the total solid content in the resist composition.

The resist solution is prepared by using a photosensitizer comprising a compound represented by the formula (I) and optionally other o-quinonediazide sulfonic acid ester, an alkali-soluble novolac resin, and a molecular weight optionally used as an additive. 90
It is carried out by mixing and dissolving a solid content of 0 or less of an alkali-soluble phenolic compound in a solvent. The solvent used here preferably has an appropriate drying rate and gives a uniform and smooth coating film after the solvent evaporates. Examples of such a solvent include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate, and propylene glycol monomethyl ether acetate, ketones such as 2-heptanone, n-amyl acetate, ethyl lactate, and ethyl pyruvate. Such as those described above, cyclic esters such as γ-butyrolactone, those described in JP-A-2-220056, those described in JP-A-4-362645, and JP-A-4-3
Examples thereof include those described in 67863. As the solvent, each compound may be used alone or in combination of two or more kinds.

The resist composition thus obtained may further contain a small amount of a resin or dye other than the novolac resin as an additive, if necessary.

[0032]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the examples, percentages and parts representing the content or the used amount are based on weight unless otherwise specified.

Reference Example 1: Monomethylolation of 2,3,5-trimethylphenol 53.4 g of 2,3,5-trimethylphenol, 19.2 g of sodium hydroxide and 400 g of water were charged into a 1-liter four-necked flask. With stirring at 2 ° C, 194.6 g of 37% formalin was added dropwise over 2 hours, and the reaction was continued at the same temperature for 2 hours. After completion of the reaction, 97.1 g of 28% aqueous ammonia was charged and stirred for 30 minutes, and then 150.3 g of acetic acid.
Then, the mixture was extracted with 800 g of methyl isobutyl ketone, washed with water and concentrated, then 40 g of toluene was charged, and the mixture was stirred at room temperature for 2 hours and then filtered. The filtered product was rinsed with toluene and then dried to obtain 45.4 g of 4-hydroxymethyl-2,3,5-trimethylphenol (purity of 98% by liquid chromatography).

Reference Example 2: Synthesis of Hydroxy Form (II) In a 100 ml three-necked flask, 4.8 g of 2-methylresorcinol, 0.4 g of 36% hydrochloric acid, and 22 g of water were charged, and the mixture was stirred at room temperature for 4- Hydroxymethyl-2,3,5-trimethylphenol (1.7 g) was added portionwise over 0.5 hour. After reacting at room temperature for another 2 hours, the precipitated crystals were filtered, and the filtered product was rinsed with ion-exchanged water. After that, it was dried under reduced pressure for a whole day and night to give 1,3-dihydroxy-4- (4-hydroxy-2,3,6-trimethylbenzyl) -2-methylbenzene (purity by liquid chromatography: 98
%) Was obtained.

Mass spectrum: MS 272 ¹ H-NMR (dimethyl sulfoxide) δ (ppm): 1.9
5 (s, 3H); 2.01 (s, 6H); 2.03 (s, 3H); 3.67 (s, 2
H); 5.91 (d, J = 8.3 Hz, 1H); 6.12 (d, J = 8.3 Hz,
1H); 6.52 (s, 1H); 8.14 (s, 1H); 8.80 (s, 1H); 8.84
(s, 1H).

Synthesis Example 1 In a 50 ml four-necked flask, 1,3-dihydroxy-4 was added.
0.5 g of-(4-hydroxy-2,3,6-trimethylbenzyl) -2-methylbenzene, 0.99 g of 1,2-naphthoquinonediazide-5-sulfonic acid chloride (molar ratio 1: 2), and 1, 4-Dioxane (7.45 g) was charged and completely dissolved, and triethylamine (0.45 g) was added dropwise thereto at 20 to 30 ° C over 1 hour. After dropping, 30 ℃
For 1 hour. Next, 0.11 g of acetic acid was added, and the mixture was stirred at the same temperature for 1 hour. The reaction mixture was filtered and the filter residue was washed with 0.99 g of 1,4-dioxane. The filtrate and the washing solution were poured into a mixed solution of 0.25 g of acetic acid and 25 g of ion-exchanged water and stirred for 1 hour. The precipitated crystals were filtered, and the obtained wet cake was washed with 50 g of ion-exchanged water while stirring.
Then, the resulting cake was filtered and dried at 40 ° C. to obtain 1.3 g of Photosensitizer A.

Mass spec: MS 736 ¹ H-NMR (dimethyl sulfoxide) δ (ppm): 1.8
9 (s, 3H); 1.95 (s, 6H); 1.98 (s, 3H); 3.80 (s, 2
H); 5.80 (d, J = 7.8 Hz, 1H); 6.12 (d, J = 7.8 Hz,
1H); 6.52 (s, 1H); 7.35 (m, 2H); 7.69 (m, 4H); 8.19
(m, 3H); 8.59 (m, 2H).

The photosensitizer A obtained above is a compound in which Q ³ in the above formula (I) is hydrogen and Q ¹ and Q ² are 1,2-naphthoquinonediazide-5-sulfonyl. Was confirmed.

Synthesis Example 2 In a 50 ml four-necked flask, 1,3-dihydroxy-4 was added.
0.5 g of-(4-hydroxy-2,3,6-trimethylbenzyl) -2-methylbenzene, 1.48 g of 1,2-naphthoquinonediazide-5-sulfonic acid chloride (molar ratio 1: 3), and 1, 4-dioxane (9.90 g) was charged and completely dissolved, and triethylamine (0.67 g) was added dropwise thereto at 20 to 30 ° C over 1 hour. After dropping, 30 ℃
For 1 hour. Next, 0.17 g of acetic acid was added, and the mixture was stirred at the same temperature for 1 hour. The reaction mixture was filtered and the filter residue was washed with 1.48 g of 1,4-dioxane. The filtrate and the washing solution were poured into a mixed solution of 0.34 g of acetic acid and 34 g of ion-exchanged water and stirred for 1 hour. The precipitated crystals were filtered, and the obtained wet cake was washed with 70 g of ion-exchanged water while stirring.
Then, the resulting cake was filtered and dried at 40 ° C. to obtain 1.6 g of Photosensitizer B.

Mass spectrum: MS 969 ¹ H-NMR (dimethyl sulfoxide) δ (ppm): 1.8
8 (s, 3H); 1.96 (s, 6H); 1.99 (s, 3H); 3.83 (s, 2
H); 5.82 (d, J = 7.6 Hz, 1H); 6.14 (d, J = 7.6 Hz,
1H); 6.54 (s, 1H); 7.40 (m, 3H); 7.70 (m, 6H); 8.20
(m, 3H); 8.62 (m, 3H).

It was confirmed that the photosensitizer B obtained above was a compound in which Q ¹ , Q ² and Q ^{3 in} the above formula (I) became 1,2-naphthoquinonediazide-5-sulfonyl. .

Reference Example 3: Production of novolac resin In a four-necked flask, 148.5 parts of m-cresol, 121.5 parts of p-cresol, and methyl isobutyl ketone 252 were prepared.
Parts, 10% oxalic acid aqueous solution 37.0 parts, and 90% acetic acid aqueous solution 84.8 parts were charged, and 37% formalin 129.5 parts was added dropwise over 40 minutes while heating and stirring in an oil bath at 100 ° C. The reaction was continued for another 15 hours. Then, it was washed with water and dehydrated to obtain 466 parts of a methyl isobutyl ketone solution containing 42.3% of novolac resin. The weight average molecular weight in terms of polystyrene measured by GPC was 4,300.

450 parts of this solution was charged into a separable flask with a bottom, and 909.6 of methyl isobutyl ketone was further added.
Parts and 996.1 parts of n-heptane, and added at 60 ° C. for 30
After stirring for a minute, the mixture was left to stand and separated. To the lower layer mass obtained by liquid separation, 380 parts of 2-heptanone was added, and methyl isobutyl ketone and n-heptane were removed by an evaporator to obtain a 2-heptanone solution of novolak resin. The polystyrene-converted weight average molecular weight by GPC is
The area ratio was 9,000, and the area ratio in the range of 900 or less in terms of polystyrene equivalent was 14% with respect to the entire pattern area.

Application Examples 1 and 2 and Comparative Example 15 parts by weight of the 2-heptanone solution of the novolac resin obtained in Reference Example 3 in terms of solid content, 4,4 '-(2-
3.9 parts of hydroxybenzylidene) di-2,6-xylenol and the photosensitizer shown in Table 1 were added to 2-heptanone so that the total amount of 2-heptanone was 50 parts, and the mixture was dissolved. This solution was filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist solution.

On a silicon wafer washed by a conventional method,
Using a spin coater, apply the above resist solution so that the film thickness after drying will be 1.1 μm, and apply 90 on a hot plate.
Bake at ℃ for 1 minute. Next, a reduction projection exposure tool with an exposure wavelength of 365 nm (i-line) [Nikon Products, NS
R 1755i 7A, NA = 0.5) was used, and the exposure amount was changed stepwise for exposure. Next, the wafer was baked on a hot plate at 110 ° C. for 1 minute. This is the developer "SOPD"
The product was developed for 1 minute with [Sumitomo Chemical Co., Ltd. product] to obtain a positive pattern. The positive pattern was evaluated as follows, and the results are shown in Table 1.

Effective Sensitivity: The line and space pattern of 0.50 μm was displayed at an exposure dose of 1: 1.

Resolution: The dimension of the line-and-space pattern, which is separated without reducing the film thickness, was measured with a scanning electron microscope at an exposure amount (effective sensitivity) at which the line-and-space pattern became 1: 1.

Profile: 0.45 in effective sensitivity
The cross-sectional shape of the μm line and space pattern was observed with a scanning electron microscope.

Focus (depth of focus): The width of the focus at which the 0.40 μm line-and-space pattern is separated without reducing the film thickness at the effective sensitivity was measured with a scanning electron microscope.

Scum: The presence or absence of scum (development residue) was observed with a scanning electron microscope.

Γ value: The normalized film thickness (= remaining film thickness / initial film thickness) was plotted against the logarithm of the exposure amount, the inclination θ was obtained, and tan θ was taken as the γ value.

[0052]

[Table 1]

^* Photosensitizer A: the photosensitizer obtained in Synthesis Example 1. Photosensitizer B: the photosensitizer obtained in Synthesis Example 2. Photosensitizer X: 4,4'-methylenebis [2- (4-hydroxybenzyl) -3,6-dimethylphenol] and 1,
Condensate of 2-naphthoquinonediazide-5-sulfonic acid chloride in a molar ratio of 1: 2. Photosensitizer Y: 4- (1 ', 2', 3 ', 4', 4'a,
9'a-hexahydro-6'-hydroxyspiro [cyclohexane-1,9'-xanthene] -4'a-yl)
Resorcinol (having the structure below)

[0054]

A condensate of 1,2-naphthoquinonediazide-5-sulfonic acid chloride in a molar ratio of 1: 3.

[0056]

The compound of formula (I) of the present invention is
It is useful as a photosensitizer for positive resists. A positive resist composition containing this compound has an excellent balance of various performances such as sensitivity, resolution, γ value, and profile, and has no scum during development, and is suitable for fine processing of semiconductors. .

Front Page Continuation (72) Inventor Kunimo Edamatsu 3-98 Kasugade, Konohana-ku, Osaka Sumitomo Chemical Co., Ltd.

Claims (8)

[Claims] (1) Formula (I) (In the formula, ^one of Q ¹ , Q ² and Q ³ represents o-quinonediazidesulfonyl, the rest independently of each other, hydrogen or o.
-Representing quinonediazidesulfonyl). 2. The compound according to claim 1, wherein Q ¹ and Q ² are o-quinonediazidesulfonyl and Q ³ is hydrogen. 3. The compound according to claim ¹ , wherein Q ¹ , Q ² and Q ³ are all o-quinonediazidesulfonyl. 4. O-quinonediazidesulfonyl is 1,2-
Naphthoquinonediazide-5-sulfonyl.
The compound according to any one of 1 to 3. 5. A photosensitizer containing the compound according to any one of claims 1 to 4 as an active ingredient. 6. A positive resist composition containing the photosensitizer according to claim 5 and an alkali-soluble novolac resin. 7. The alkali-soluble novolak resin is a condensate of a phenolic compound and an aldehyde, and the area ratio of the polystyrene-reduced molecular weight in the range of 900 or less in the gel permeation chromatography pattern is that of an unreacted phenolic compound. The composition according to claim 6, which is 25% or less of the total pattern area excluding the pattern area. 8. The composition according to claim 6, further comprising an alkali-soluble phenolic compound having a molecular weight of 900 or less.