JPH05134411A - Negative resist composition - Google Patents

Abstract

PURPOSE:To form a fine pattern with high sensitivity and high resolution without swelling with a developer by incorporating specified amts. of alkali-soluble resin obtd. by polymn. of arylphenol as the monomer component and a radiation- sensitive acid forming agent. CONSTITUTION:This compsn. contains 100 pts.wt. of alkali-soluble resin obtd. by polymn. of arylphenol as the monomer component and 0.01-15 pts.wt. of radiation-sensitive acid forming agent. Or, the compsn. contains 100 pts.wt. of alkali-soluble resin and 0.1-40 pts.wt. of compd. containing acid group (-N3). The alkali-soluble resin is preferably a polymer obtd. by polymn. condensation of phenols containing aryl phenol and aldehyde in the presence of an acid catalyst. The radiation-sensitive acid forming agent is a compd. which produces acid by irradiation, for example, onium salt, halogen-contg. compd. 1,2- quinodiazide compd. etc.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a negative resist composition. More specifically, the present invention relates to a negative resist composition suitable as a resist for forming highly integrated circuits, which is sensitive to radiation such as ultraviolet rays, far ultraviolet rays, X-rays and charged particle beams.

[0002]

2. Description of the Related Art In the field of microfabrication represented by the manufacture of integrated circuit devices, in recent years, in order to obtain a higher degree of integration, development of a lithography process which enables microfabrication of 0.5 μm or less has been advanced. There is.

Recently, it has been found that when resists are applied to a phase shift lithographic process, high resolution is obtained due to the increased contrast of radiation. But,
When the positive resist is applied to the above process, when forming an isolated pattern, the intensity of the radiation is attenuated due to the phase shift at the boundary of the shifter used for the phase shift, so that the portion originally developed and removed remains, which is inconvenient. Was occurring. Therefore, a negative resist having excellent performance is strongly desired.

[0004]

An object of the present invention is to provide a new negative resist composition. Another object of the present invention is a negative resist composition suitable for a phase shift lithographic process, suitable for use as a resist composition capable of forming a fine pattern with high sensitivity and high resolution without swelling by a developing solution. To provide. Further objects and advantages of the present invention will be apparent from the following description.

[0005]

According to the present invention, the above objects and advantages of the present invention are as follows. Firstly, an alkali-soluble resin 100 obtained by using allylphenol as a monomer component.
The present invention is achieved by a negative resist composition (hereinafter, referred to as "first invention"), characterized by containing 0.01 part by weight and a radiation-sensitive acid forming agent in an amount of 0.01 to 15 parts by weight.

Secondly, a negative resist composition containing 100 parts by weight of an alkali-soluble resin obtained by using allylphenol as a monomer component and 0.1 to 40 parts by weight of an azide group (-N ₃ ) -containing compound. Thing (hereinafter,
It is achieved by "the second invention").

The alkali-soluble resin used in the present invention is a polymer obtained by using allylphenol as a monomer component. As such an alkali-soluble resin,
For example, the following formula (I) obtained by polycondensing phenols including allylphenol and aldehydes in the presence of an acid catalyst such as formic acid, oxalic acid and hydrochloric acid

[0008]

[Chemical 1]

A polymer containing a structural unit represented by (hereinafter referred to as "resin (A)") or a compound having a double bond containing allylphenol, which is obtained by addition polymerization, is represented by the following formula (II).

[0010]

[Chemical 2]

A polymer containing a structural unit represented by (hereinafter referred to as "resin (B)") is preferably used.

Examples of the above-mentioned allylphenol include o-allylphenol, m-allylphenol, p-allylphenol and the like. Among them, o-allylphenol is preferably used.

The phenols other than allylphenol (hereinafter referred to as "other phenols") used for obtaining the resin (A) are not particularly limited, and examples thereof include phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,5-
Examples include xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol, catechol, resorcinol, hydroquinone, phloroglicinol and pyrogallol. Among them, phenol, m-cresol,
2,3-xylenol, 2,5-xylenol, 3,5-
Xylenol, 2,3,5-trimethylphenol, resorcinol and the like are preferably used.

The use ratio of allylphenol and other phenols is usually allylphenol / other phenols = 5 to 100/95 to 0 (molar ratio), preferably 30 to 100/70. It is 0 (molar ratio).

Examples of aldehydes include formaldehyde, benzaldehyde, hydroxybenzaldehyde, acetaldehyde, propylaldehyde, phenylacetaldehyde and the like. In particular, formaldehyde can be preferably used. Sources of this formaldehyde include formalin, trioxane, paraformaldehyde, methyl hemiformal, ethyl hemiformal, propyl hemiformal,
Hemiformals such as butyl hemiformal and phenyl hemiformal can be mentioned. Particularly, formalin and butyl hemiformal can be preferably used. These aldehydes can be used alone or in combination of two or more kinds.

The resin (A) used in the present invention
Is a polystyrene-converted weight average molecular weight (hereinafter, “Mw”)
Is preferably in the range of 1,000 to 20,000, more preferably 4,000 to 15,000. When Mw exceeds 20,000, it becomes difficult to uniformly apply the composition of the present invention to a wafer, and further developability tends to deteriorate, and when Mw is less than 1,000, it becomes difficult to form a resist film. ..

Examples of the compound having a double bond other than allylphenol used for obtaining the resin (B) (hereinafter referred to as "a compound having another double bond") include, for example, butadiene, acrylic acid and methacrylic acid. , Methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, styrene, α-methylstyrene, chloromethylstyrene, vinylphenol, vinylbenzoic acid and the like are preferably used.

Here, the usage ratio of allylphenol and the compound having other double bond is usually allylphenol / compound having other double bond = 5 to 100/95.
To 0 (molar ratio), preferably 10 to 100/90
Is 0 (molar ratio).

Cationic polymerization of these monomers using boron trifluoride, hydrogen iodide or the like as a polymerization initiator,
Alternatively, the resin (B) is obtained by addition polymerization by radical polymerization using azobisisobutyronitrile (hereinafter referred to as AIBN), benzoyl peroxide or the like as a polymerization initiator.

The resin (B) used in the present invention is
The Mw is preferably in the range of 1,000 to 100,000, more preferably 4,000 to 30,000. If the Mw exceeds 100,000, it becomes difficult to uniformly apply the composition of the present invention to a wafer, and the developability tends to decrease, and if the Mw is less than 1,000,
It becomes difficult to form a resist film. In the composition of the present invention, the above-mentioned resin (A) and resin (B) can be used alone or in combination of two or more.

In the negative resist composition of the first invention of the present invention, a radiation-sensitive acid forming agent is used as the radiation-sensitive compound. The radiation-sensitive acid forming agent is a compound that generates an acid upon irradiation with radiation, and is, for example, JP-A-60-1.
15932, JP-A-60-37549, JP-A-60-52845, and JP-A-63-29212.
The compounds disclosed in JP-A No. 8 and JP-A-1-293339, for example, onium salts, halogen-containing compounds, 1,2-quinonediazide compounds, nitrobenzyl esters, sulfonates and the like can be exemplified.

The onium salt is represented by the following formula (II
I)

[0023]

[Chemical 3]

A compound represented by the formula:
V)

[0025]

[Chemical 4]

The compounds represented by are preferably used.
The halogen-containing compound is represented by the following formula (V)

[0027]

[Chemical 5]

A compound represented by the formula:
I)

[0029]

[Chemical 6]

The compounds represented by are preferably used.
The 1,2-quinonediazide compound is a compound having a diazide group (= N ₂ ), and has, for example, the following formula (VI
I-) to (VII-)

[0031]

[Chemical 7]

A compound represented by the following formula (VI)
II)

[0033]

[Chemical 8]

The compounds represented by are advantageously used.
Further, the above nitrobenzyl ester has the following formula (IX)

[0035]

[Chemical 9]

The compounds represented by are preferably used.
Furthermore, as the sulfonic acid ester, the following formula (X)

[0037]

[Chemical 10]

A compound represented by the following formula (XI)

[0039]

[Chemical 11]

A compound represented by the following formula (XII)

[0041]

[Chemical 12]

A compound represented by the formula:
III)

[0043]

[Chemical 13]

The compounds represented by are preferably used.
Among these, the compound represented by the formula (III) which is an onium salt, the compound represented by the formula (VII-) which is a 1,2-quinonediazide compound or the formula (IX) which is a nitrobenzyl ester is preferable. Used as an agent.

These radiation-sensitive acid forming agents may be used alone or in combination of two or more. The amount of the radiation-sensitive acid forming agent added is 0.01 to 15 parts by weight, preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the alkali-soluble resin. When the amount of the radiation-sensitive acid forming agent added is less than 0.01 parts by weight, the radiation-irradiated portion is hard to be insoluble in the developing solution
If it exceeds 15 parts by weight, the unirradiated portion may not be developed.

The azido group-containing compound used in the second invention is a compound which decomposes upon irradiation with radiation to crosslink the alkali-soluble resin, or changes the polarity to make it insoluble in the developing solution. Such compounds include, for example, 1-azidopyrene, p-azidobenzophenone, 4 '.
Monoazide compounds such as 4-methoxy-4-azidodiphenylamine, 4-azidobenzal-2'-methoxyacetophenone, 4-azido-4'-nitrophenylazobenzene, 4,4'-diazidobenzophenone, 4,4'-
Diazidobenzomethane, 4,4'-diazidostilbene, 2,2'-di (ethanolsulfonamide) -4,
4'-diazidostilbene, 4,4'-diazidochalcone, 2-diethoxyethylsulfonamide-4,4'-
Diazidochalcone, 4,4'-diazidodiphenyl sulfone, 3,4'-diazidodiphenyl sulfone, 3,3 '
-Diazidodiphenyl sulfone, 2,6-di (4'-azidobenzal) cyclohexane, bisazide compounds such as 2,6-di (4'-azidobenzal) 4-methylcyclohexane, sulfonylazidobenzene, p-sulfonylazidotoluene and the like Monosulfonyl azide compound and p-bis (sulfonyl azido) benzene, 4,4 ′
Bis (sulfonyl azido) benzophenone and other bis sulfonyl azide compounds.

Among these, the bisazide compound is used as a preferred azide group-containing compound. These azido group-containing compounds may be used alone or in combination of two or more. The addition amount of the azido group-containing compound is usually 0.1 to 40 parts by weight, preferably 1 to 30 parts by weight, based on 100 parts by weight of the alkali-soluble resin. If the addition amount of the azido group-containing compound is less than 0.1 part by weight, the radiation-irradiated portion is less likely to be insolubilized in the developing solution, and if it exceeds 40 parts by weight, the pattern becomes inversely tapered and the pattern shape deteriorates.

In addition to the alkali-soluble resin, the radiation-sensitive acid forming agent or the azide group-containing compound, various additives may be added to any of the above negative resist compositions of the present invention, if necessary. it can. As such an additive, for example, a surfactant for improving the coating property and the developing property can be mentioned. As such a surfactant, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octylphenol ether, polyoxyethylene nonylphenol ether, polyethylene glycol dilaurate, polyethylene glycol distearate, commercially available As the product, for example, F-top EF301, EF303, EF35
2 (manufactured by Shin-Akita Kasei Co., Ltd.), Megafax F171,
Same F173 (Dainippon Ink Co., Ltd.), Florard FC
430, FC431 (Sumitomo 3M Limited), Asahi Guard AG710, Surflon S-382, SC1
01, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.), organosiloxane polymer KP341 (Shin-Etsu Chemical Co., Ltd.)
Polyflow No. 75, No. 95 (manufactured by Kyoeisha Oil and Fat Chemical Co., Ltd.) which is an acrylic acid-based or methacrylic acid-based (co) polymer.

The amount of the surfactant used is preferably 2 parts by weight or less with respect to 100 parts by weight of the alkali-soluble resin. Further, other additives include a sensitizer, an antihalation agent, an adhesion aid, a safety stabilizer, and a defoaming agent.

The negative resist composition of the present invention comprises the above-mentioned alkali-soluble resin, radiation-sensitive acid forming agent or azide group-containing compound, and various additives to be added if necessary.
It is prepared by dissolving each in the required amount in a solvent.

Examples of the solvent used in this case include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol dimethyl ether, and diethylene glycol. -Diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol Rumonopropyle
Tellacetate, toluene, xylene, methyl ethyl ketone, cyclohexanone, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, 2-hydroxy-3. −
Methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, 3-methyl-3-methoxybutyl butyrate, ethyl acetate, butyl acetate, methyl acetoacetate, ethyl acetoacetate, methyl 3-methoxypropionate, 3- Examples thereof include ethyl ethoxypropionate, N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide and the like.

If necessary, these solvents may be benzyl ethyl ether, dihexyl ether, diethylene glycol monomethyl ether, diethylene glycol ether.
Rumonoethyl ether, acetonylacetone, isophorone, caproic acid, caprylic acid, 1-octanol, 1-
Nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate,
γ-butyrolactone, ethylene carbonate, propylene carbonate,
A high boiling point solvent such as phenyl cellosolve acetate can also be added.

The composition of the present invention is applied onto a substrate such as a silicon wafer in the form of the above solution and dried to form a resist film. In this case, for coating on a substrate, for example, the composition of the present invention is dissolved in the above solvent so as to be 5 to 50% by weight in terms of solid content, filtered, and then spin-coated, flow-coated, spin-coated. It is carried out by applying, for example, a coating.

The formed resist film is partially irradiated with radiation to form a fine pattern. The radiation used is not particularly limited and, for example, ultraviolet rays, deep ultraviolet rays, X-rays, charged particle beams, etc. are used depending on the type of the radiation-sensitive acid forming agent or azide group-containing compound used. Irradiation conditions such as radiation dose, the composition of the composition,
It is appropriately determined according to the kind of each addition amount.

In the present invention, in order to improve the performance of the negative resist, it is preferable to perform heating after irradiation with radiation. The heating condition varies depending on the composition of the composition, the type of each additive, etc., but is usually 30 to 200.
C., preferably 50 to 150.degree.

Examples of the developer used for the subsequent development include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine and di-. n-propylamine, triethylamine, methyldiethylamine, dimethylethano-
Ruamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrol, piperidine, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,5-diazabicyclo- [4.3] .0] -5-nonane in which an alkaline aqueous solution or the like is dissolved can be used.

Further, this developing solution contains a water-soluble organic solvent,
For example, an alkaline aqueous solution to which alcohols such as methanol and ethanol and a surfactant are appropriately added can be used as a developing solution. As the developer, the solvent used for preparing the composition solution, acetone, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol, isopropanol and the like can be used, but it is preferable to use an alkaline aqueous solution in view of resolution. preferable.

[0058]

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. The measurement of Mw and the evaluation of the resist in the examples were performed by the following methods.

Mw: Tosoh GPC column (G200
0HXL 2 pcs, G3000HXL 1 pcs, G4000HXL
1) and a flow rate of 1.0 ml / min, an elution solvent of tetrahydrofuran, and a column temperature of 40 ° C. were analyzed by gel permeation chromatography using monodisperse polystyrene as a standard.

Sensitivity: Nikon NSR-1505i6
A Reduced projection exposure machine (numerical aperture of the lens; 0.45) is used to change the exposure time, and exposure is performed using i-line with a wavelength of 365 nm (hereinafter referred to as "i-line exposure"), or Admon Science. Company KrF excimer laser MB
K-400TL-N is used to bring the mask into close contact with the exposure (hereinafter,
"Excimer exposure"), followed by baking, followed by development with an aqueous solution of tetramethylammonium hydroxide, rinsing with water, and drying to form a resist pattern on the wafer, and a line and An exposure amount for forming a space pattern (1L1S) in a width of 1: 1 (hereinafter, referred to as “optimal exposure amount”) was determined.

Resolution: The dimension of the smallest resist pattern resolved when exposed at the optimum exposure amount was measured.

Synthesis Example 1 In a flask equipped with a stirrer, a condenser and a thermometer, o
-Allylphenol 53.7 g (0.40 mol), 37% by weight aqueous formaldehyde solution 73.0 g (formaldehyde: 0.90 mol) and oxalic acid dihydrate 0.63 g.
(0.005 mol) was charged, polycondensation was performed for 60 minutes while maintaining the internal temperature at 100 ° C., and then 56.5 g (0.60 mol) of phenol was added and polycondensation was further performed for 120 minutes. .. Then, the temperature of the oil bath was raised to 180 ° C., and at the same time, the pressure inside the flask was reduced to 30 to 50 mmHg to remove volatile matter. Next, the molten resin was returned to room temperature and recovered. This resin is referred to as resin (A1).

Synthesis Example 2 A flask similar to Synthesis Example 1 was charged with o-allylphenol 1
Charge 34.2 g (1.0 mol), 37 wt% formaldehyde aqueous solution 162.3 g (formaldehyde: 2.0 mol) and oxalic acid dihydrate 6.3 g (0.05 mol), and set the internal temperature to 100 ° C. While maintaining the temperature at 40 ° C., polycondensation was performed for 240 minutes while stirring. Then, the resin was recovered by the same operation as in Synthesis Example 1. This resin is referred to as resin (A2).

Synthesis Example 3 53.7 g (0.40 mol) of o-allylphenol, 57.2 g (0.55 mol) of styrene, and p- were added to a flask equipped with a stirrer, a cooling pipe, a gas introduction pipe and a thermometer. 7.4 g (0.05 mol) vinylbenzoic acid and 24 dioxane
0 g was charged, this was immersed in an oil bath, and the internal temperature was kept at 65 ° C. under a nitrogen stream while stirring and AIBN 8.21 g
(0.05 mol) was added and addition polymerization was carried out for 15 hours.
The contents were then concentrated and dried to recover the resin. This resin is referred to as resin (B1).

Comparative Synthesis Example 1 m-Cresol 64.8 was placed in the same flask as in Synthesis Example 1.
g (0.60 mol), p-cresol 43.3 g (0.4
0 mol), 37% by weight formaldehyde aqueous solution 73.0
g (formaldehyde: 0.90 mol) and oxalic acid dihydrate 0.63 g (0.005 mol) were charged, and polycondensation was carried out for 120 minutes while stirring while maintaining the internal temperature at 100 ° C. Then, the resin was recovered by the same operation as in Synthesis Example 1. This resin is referred to as a resin (C1).

Comparative Synthesis Example 2 In a flask similar to that used in Synthesis Example 2, 83.2 g of styrene (0.
80 mol), p-vinylbenzoic acid 29.6 g (0.20 mol) and dioxane 240 g were charged, this was immersed in an oil bath, the internal temperature was kept at 65 ° C. under a nitrogen stream, and AIBN8. 21 g (0.05 mol) was added and polymerization was carried out for 15 hours. The contents were then concentrated and dried to recover the resin. This resin is referred to as a resin (C2).

Example 1 2 g of 10.0 g of Resin (A1) and 0.5 g of 1,2-naphthoquinonediazide-4-sulfonic acid ester of 2,3,4-trihydroxybenzophenone (esterification rate 90%) were used.
-Dissolved in 27.0 g of ethyl hydroxypropionate,
The composition was prepared by filtration through a 0.2 μm membrane filter. This composition was spin-coated on a 4-inch silicon wafer by a spinner so that the film thickness would be 1.2 μm, and prebaked at 90 ° C. for 120 seconds on a hot plate. This was subjected to i-line exposure, baked on a hot plate at 110 ° C. for 60 seconds, and then developed. After development, when observed with a scanning electron microscope (Hitachi S-530), the sensitivity was 160 mJ / cm ² and a negative line-and-space pattern having a resolution of 0.44 μm was obtained.

Example 2 Resin (A1) (10.0 g) and 9,10-diethoxyanthracene-2-sulfonic acid-4-nitrobenzyl (0.5 g) were dissolved in methyl 3-methoxypropionate (27.0 g).
The composition was prepared by filtration through a 0.2 μm membrane filter. This composition was spin-coated on a 4-inch silicon wafer by a spinner so as to have a film thickness of 1.0 μm, and prebaked at 90 ° C. for 120 seconds on a hot plate. This was subjected to excimer exposure, baked on a hot plate at 80 ° C. for 120 seconds, and then developed. When this was observed in the same manner as in Example 1, the sensitivity was 30 mJ / c.
m ² and a negative line-and-space pattern having a resolution of 0.42 μm was obtained.

Example 3 10.0 g of Resin (B1) and 2.5 g of 2,2'-di (diethanolsulfonamide) -4,4'-diazidostilbene
Was dissolved in 37.5 g of ethyl 2-hydroxypropionate and filtered through a 0.2 μm membrane filter to prepare a composition. When this composition was operated in the same manner as in Example 1 and observed with a scanning electron microscope, the sensitivity was 150 mJ / cm ² , and a negative line-and-space pattern having a resolution of 0.44 μm was obtained. ..

Example 4 Resin (A1) was used instead of resin (B1) in Example 3.
When the same operation as in Example 3 was carried out except that 10.0 g was used, the sensitivity was 170 mJ / cm ² and a negative line-and-space pattern having a resolution of 0.44 μm was obtained.

Example 5 Resin (A2) was used instead of resin (B1) in Example 3.
The same operation as in Example 3 was carried out except that 10.0 g was used. As a result, a negative line-and-space pattern having a sensitivity of 150 mJ / cm ² and a resolution of 0.44 μm was obtained.

Example 6 10.0 g of resin (A2) and 0.5 g of triphenylsulfonium triflate were dissolved in 27.0 g of ethyl 2-hydroxypropionate and the same operation as in Example 2 was carried out. 35 mJ / cm ² and resolution 0.42
A μm negative line-and-space pattern was obtained.

Comparative Example 1 Resin (C2) was used instead of resin (A1) in Example 1.
When the same operation as in Example 1 was performed except that 10.0 g was used, no pattern was formed.

Comparative Example 2 Resin (C1) was used instead of resin (B1) in Example 3.
When the same operation as in Example 3 was carried out except that 10.0 g was used, only a line-and-space pattern having a resolution of 1.5 μm was obtained.

[0075]

INDUSTRIAL APPLICABILITY The negative resist composition of the present invention is suitable for a phase shift lithography process, does not swell with a developing solution, and can be suitably used as a resist excellent in sensitivity and resolution.

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI Technical indication location H01L 21/027 (72) Inventor Takao Miura 2-11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. Within

Claims (2)

[Claims] 1. A negative resist composition comprising 100 parts by weight of an alkali-soluble resin obtained by using allylphenol as a monomer component and 0.01 to 15 parts by weight of a radiation-sensitive acid forming agent. 2. A negative resist composition containing 100 parts by weight of an alkali-soluble resin obtained by using allylphenol as a monomer component and 0.1 to 40 parts by weight of a compound containing an azide group (—N ₃ ).