JP3031214B2 - Anti-reflective coating material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is particularly suitable for fine processing technology which has a high sensitivity to high energy rays such as far ultraviolet rays, electron beams and X-rays and can form a pattern by developing with an alkaline aqueous solution. The present invention relates to an antireflection film material effective for forming a lower layer of a chemically amplified resist film.

[0002]

2. Description of the Related Art LSI
With high integration and high speed of GaN, far ultraviolet lithography is expected as a next-generation microfabrication technology. The deep ultraviolet lithography can also process 0.3 to 0.4 μm, and when a resist material having low light absorption is used, a pattern having side walls nearly perpendicular to the substrate can be formed. Further, in recent years, a technique using a KrF excimer laser as a light source of far ultraviolet light has attracted attention, and a resist material having low light absorption and high sensitivity has been demanded for use as a mass production technique.

[0003] From such a point, a chemically amplified positive resist material using an acid as a catalyst recently developed (Japanese Patent Publication No. 2-27).
660, JP-A-63-27829, and U.S. Pat. Nos. 4,491,628 and 5,310,619) are excellent in sensitivity, resolution, and dry etching resistance. It is a particularly promising resist material for deep ultraviolet lithography having features.

However, in deep-ultraviolet lithography, a standing wave (S
dimensional accuracy of the resist image is degraded due to the influence of a standing wave), furthermore, when there is a step in the substrate, the influence of light interference due to the variation in the thickness of the resist layer at the step, and the influence of halation from the step. This causes a problem that processing cannot be performed to an accurate pattern size.

Further, in the case of a chemically amplified resist material, where the substrate dependence of the pattern profile is a nitride film, the contact of the resist pattern 5 on the substrate 1 with the substrate as shown in FIG. Hemming in part (Foot
1), there is a problem that notching occurs in the contact portion of the resist pattern 5 on the substrate 1 with the substrate as shown in FIG. 1B (Hashijima et al., Spring 1994). Proceedings of the Japan Society of Applied Physics, p566, 29a, MB-10 / Fukushima et al., 199
Proceedings of the Japan Society of Applied Physics Spring 2014, p566, 29p,
MB-1). It is considered that this occurs because the NH bond in the nitride film deactivates the acid at the interface between the chemically amplified resist film and the nitride film substrate.

Therefore, as a pattern forming method which solves the above problems, an ARC (anti-reflection film formed under a resist) method has been proposed (BW Dudley.e).
t. al. , SPIE Vol. 1672 Advances in Resist Technology and Processing
hnology and Processing) I
X, 638 (1992). / Tani et al., Proceedings of the Society of Applied Physics, Spring 1994, p567, 29p, MB-4). As the ARC method, a method using an inorganic film or an organic film as an antireflection film is generally used. In the ARC method using an inorganic film, a method by sputtering or CVD (chemical vapor deposition) is used to form the inorganic film. There is a problem that it has to be taken and the equipment for that is very expensive.

The ARC method using an organic film has the advantage that the apparatus for forming the organic film is only an inexpensive coater and the processing time is shorter than that of the inorganic film, so that the throughput is better. UV (wavelength 245-25)
5 nm) In lithography, an imaginary part k of a complex refractive index in far ultraviolet rays, that is, an extinction coefficient k of 0.3 or more, which is a characteristic required for processing into an accurate pattern size, is 0.3 or more.
In addition, there is still a problem that there is no material that satisfies the condition of "not causing hemming or notching".
Further, instead of the currently known chemically amplified resist material, an antireflection film material for a general-purpose resist material using a diazonaphthoquinone compound (see Japanese Patent Publication No. 6-12452) uses a polyamic acid as a main component. After the formation, for example, by performing a heat treatment at 140 ° C. or more for 30 minutes or more to use a technique of chemically converting into polyimide, the extinction coefficient k is satisfied. Cannot convert the NH bond (amine residue and terminal amine residue in the polyamic acid main chain) into an imide group which is an inactive group, and generates ammonia by heating at a high temperature. It is not suitable because it causes notching. The anti-reflective coating material for general-purpose resists using other diazonaphthoquinone compounds (US Pat. No. 5,234,990) uses polysulfone as a main component, and therefore does not cause tailing and notching. The value of the extinction coefficient k does not satisfy the required value.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is intended to provide a lower layer of a chemically amplified resist film capable of forming a resist pattern with fineness, high dimensional accuracy, high productivity, and high reproducibility. It is an object of the present invention to provide an antireflection film material effective for forming a film.

[0009]

Means for Solving the Problems and Embodiments of the Invention As a result of intensive studies to achieve the above object, the present inventor has found that high energy rays such as far ultraviolet rays, electron beams and X-rays, particularly far ultraviolet rays ( As an antireflection film material used as a lower layer of a chemically amplified resist film having a high sensitivity to a wavelength of 245 to 255 nm and suitable for a fine processing technique by an ARC method capable of forming a pattern by developing with an aqueous alkali solution, By blending, as a main component, a polyimide soluble in a solvent and an aqueous alkali solution, particularly a polymer having a repeating unit represented by the following general formula (1) or (2), the above-mentioned characteristics required in deep ultraviolet lithography can be obtained. A certain "imaginary part k of the complex refractive index in far ultraviolet light,
That is, it has been found that the material can satisfy the conditions of “the extinction coefficient k is 0.3 or more” and “does not cause tailing or notching”.

[0010]

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[0011]

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That is, when a pattern is formed by an ARC method in which an anti-reflection layer is formed of an anti-reflection film material mainly composed of a polyimide soluble in an organic solvent and an aqueous alkali solution, the extinction coefficient k becomes 0.3 or more, -Since the reflectance of light at the interface of the anti-reflection layer can be suppressed and the transmittance can be significantly reduced, the amount of variation in pattern dimensions due to standing waves and halation in the resist layer can be suppressed as compared with a single resist layer. Therefore, the dimensional accuracy of the resist image can be improved, and in particular, by modifying the terminal amine residue with a phthalic anhydride derivative or the like, the N—H bond can be removed, thereby causing tailing and notching. In addition, it is not necessary to perform a heat treatment for a long time at a high temperature of, for example, 140 ° C. or more and 30 minutes or more. Was knowledge. In addition, since it is soluble in an alkaline aqueous solution, it can be developed and removed together with the resist film, and the step of selectively etching using oxygen plasma or the like can be omitted, and the process can be shortened.

Further, for the purpose of supplying acid to the interface between the resist film and the anti-reflection layer in the exposed portion, an acid generator or an organic acid is added to the anti-reflection film material to thereby improve the dimensional accuracy of the resist image. Was found to be able to be improved, and the present invention was achieved.

Therefore, the present invention comprises a repeating unit represented by the above general formula (1) or (2), comprising a polyimide soluble in an organic solvent and an aqueous alkaline solution, and an organic solvent. An anti-reflective coating material characterized by the following.

Hereinafter, the present invention will be described in more detail. The polyimide soluble in an organic solvent and an aqueous alkaline solution which is a main component of the antireflection film material of the present invention is soluble in an organic solvent which can be spin-coated, which will be described later. Various polyimides can be used as long as they have a logarithmic viscosity range of 0.01 to 5 dl / g, particularly 0.05 to 1 dl / g.
Are preferred. Logarithmic viscosity range is 0.01 dl / g
If less than 5 dl / g, a film cannot be formed.
If it exceeds, the solution viscosity becomes high and handling becomes difficult.

The logarithmic viscosity is such that the polyimide concentration is 0.5
g / 100 ml using a solution of DMF (N, N-dimethylformamide) under the measurement conditions of 30 ° C. can be obtained by the following equation.

[0017]

(Equation 1)

As the polyimide soluble in the organic solvent and the aqueous alkali solution, a polymer having a repeating unit represented by any of the following general formulas (1) and (2) is used.

[0019]

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[0020]

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Here, the polyimides represented by the above general formulas (1) and (2) are the same as the tetracarboxylic dianhydride represented by the following general formula (3) and the polyimide represented by the following general formula (4) or (5). Is prepared by polycondensing an aromatic diamine having a phenolic hydroxyl group with a phthalic anhydride derivative represented by the following general formula (6) in a suitable solvent, followed by heat imidization according to a conventional method. It can be produced by performing imide conversion.

[0022]

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Specific examples of the tetracarboxylic dianhydride represented by the above general formula (3) include 3,3 ', 4,4'-
Biphenyltetracarboxylic dianhydride, 2,2 ', 3
3′-biphenyltetracarboxylic dianhydride, 3,
3 ', 4,4'-benzophenonetetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether anhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride, bis (3,4
-Dicarboxyphenyl) methane, 2,2-bis (3,
4-dicarboxyphenyl) propane dianhydride and the like, and one or more of these tetracarboxylic dianhydrides can be used in combination.

Further, specific examples of the aromatic diamine having a phenolic hydroxyl group represented by the general formulas (4) and (5) include bis (3-amino-4-hydroxyphenyl) ether and bis (4-aminophenyl) ether. Amino-3-hydroxyphenyl) ether, bis (3-amino-4-hydroxyphenyl) methane, bis (4-amino-3-hydroxyphenyl) methane, bis (3-amino-4-hydroxyphenyl) sulfone, bis ( 4-amino-3-hydroxyphenyl) sulfone, 2,2-bis (3-amino-4-
Hydroxyphenyl) propane, 2,2-bis (4-amino-3-hydroxyphenyl) propane, 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, 2,2-bis (4-amino -3-hydroxyphenyl) hexafluoropropane, 4,4'-diamino-3,3'-dihydroxybiphenyl, 3,3 '
-Diamino-4,4'-dihydroxybiphenyl, 1,
3-bis (3-amino-4-hydroxyphenoxy) benzene, 1,4-bis (4-amino-3-hydroxyphenoxy) benzene, 1,3-bis (4-amino-3-
(Hydroxyphenoxy) benzene, bis [4- (3-amino-4-hydroxyphenoxy) phenyl] sulfone, bis [4- (4-amino-3-hydroxyphenoxy) phenyl] sulfone, 2,2-bis [4- ( 3-amino-4-hydroxyphenoxy) phenyl] propane, 2,2-bis [4- (4-amino-3-hydroxyphenoxy) phenyl] propane, 2,2-bis [4-
(3-Amino-4-hydroxyphenoxy) phenyl]
Hexafluoropropane, 2,2-bis [4- (4-amino-3-hydroxyphenoxy) phenyl] hexafluoropropane, and the like. One of these aromatic diamines is used alone, or two or more are used in combination. can do.

As the monovalent organic group for modifying the terminal amino group, succinic anhydride derivatives of aliphatic hydrocarbons and the like can be used. In order to increase the k value, the above general formula (6) The aromatic hydrocarbons represented by ()) are preferred.
Specifically, phthalic anhydride, 4-methylphthalic anhydride,
4-fluorophthalic anhydride, 4-nitrophthalic anhydride,
Examples thereof include 4-chlorophthalic anhydride and 4-bromophthalic anhydride.

The equations (3) and (4) or (5),
The reaction molar ratio of the compound (6) is from 100: 130: 60.
Preferably, the ratio is 100: 102: 4.

Preferred solvents for producing the polyimide of the present invention include N-methyl-2-pyrrolidone,
N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, dimethylsulfone,
Diethylene glycol dimethyl ether, hexamethylsulfonamide, N-methyl-ε-caprolactam, tetramethylurea, hexamethylphosphoric triamide, cyclohexanone, γ-butyrolactone, and the like can be used. One or more of these can be used in combination. can do.

In the case of ring closure by dehydration by heating, polyimide can be produced by azeotropically producing water by-product of imidization in the presence of an organic solvent which forms an azeotrope with water, such as toluene, xylene and chlorobenzene. it can. The reaction temperature is 150 to 400 ° C, preferably 1 to 400 ° C.
80-350 ° C. At temperatures lower than 150 ° C., imidization proceeds only partially, and at temperatures higher than 400 ° C., decomposition may occur. The reaction time is 30 seconds to 10 hours, preferably 5 minutes to 5 hours. After completion of the reaction, it is preferably used after pouring into a large amount of water or a poor solvent to precipitate a polymer, washing and drying to obtain a solid.

The amount of the polyimide soluble in the organic solvent and the aqueous alkali solution is adjusted so that the thickness of the antireflection film layer is 100 to 20.
In order to set the thickness to 00 ° (0.01 to 0.2 μm), the thickness is preferably 1 to 20% (% by weight, the same applies hereinafter), particularly 3 to 10%, and if less than 1%, the film thickness becomes thinner than 100 °. In some cases, the anti-reflection effect is reduced, and if it exceeds 20%, the fluidity of the solution becomes poor, and it may be difficult to form a uniform coating film.

Next, as the organic solvent, those which can be spin-coated are desirable. For example, ketones such as cyclohexanone, ethers such as propylene glycol dimethyl ether and diethylene glycol dimethyl ether,
Esters such as methyl-3-methoxypropionate and ethyl-3-ethoxypropionate can be mentioned, and these can be used alone or in combination of two or more. Among them, polyimide soluble in an organic solvent and an aqueous alkali solution, cyclohexanone, diethylene glycol dimethyl ether, and methyl-3-methoxypropionate, which have the highest solubility of an acid generator, are preferably used.

It is preferable that an acid generator is further added to the antireflection coating material of the present invention for the purpose of supplying acid to the interface between the resist film and the antireflection layer in the exposed portion.

As the acid generator, for example, onium salts, pi
Rogalol trimesylate derivative, oximesulfonic acid
Derivatives, 2,6-dinitrobenzylsulfonic acid derivatives,
Diazonaphthoquinonesulfonic acid derivative, 2,4-vist
Lichloromethyl-6-aryl-1,3,5-triazi
Derivatives, α, α'-bisarylsulfonyldiazomes
Tan derivatives and the like;
Onium salts represented by the formula (7) are preferably used. (R ’)_mMY (7) (wherein, R 'Is the same or different unsubstituted or substituted aromatic
The group, M is sulfonium or iodonium, Y is substituted or
Unsubstituted alkyl or aryl sulfonates. m
Is 2 or 3. )

Here, examples of the aromatic group include a phenyl group, a phenyl group substituted with an alkyl group having 1 to 10 carbon atoms or an alkoxy group, and the like.

Specific examples of the onium salt of the above formula (7) include the following iodonium salts and sulfonium salts.

[0035]

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The amount of the acid generator is preferably 1 to 100 parts, more preferably 3 to 25 parts, per 100 parts (parts by weight, hereinafter the same) of polyimide soluble in an organic solvent and an aqueous alkali solution.
If the amount is less than 1 part, the supply of acid to the interface between the resist film and the antireflection layer in the exposed part becomes insufficient, and the effect of the addition of the acid generator may hardly be obtained. .3 may not be satisfied.

Further, in the present invention, a surfactant may be added in order to improve coatability. Further, depending on the reflectance characteristics of the substrate, far ultraviolet rays (wavelengths of 245 to 255 n
m) At least one light absorbing agent having a molar extinction coefficient in the region of 20,000 or more can be added. In order to supply an acid to the antireflection layer, for example, an organic acid such as acetic acid, propanoic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, and trifluoroacetic acid can be added. In addition, the addition amount of the surfactant, the light absorbing agent, and the organic acid can be a normal amount as long as the effects of the present invention are not impaired.

The anti-reflective coating material of the present invention can be obtained by mixing the above components, and has a wavelength of 245 to 255.
Although it is most suitable for fine patterning by far ultraviolet light of nm and KrF excimer laser of wavelength 248 nm, there is no problem if it is used as an antireflection film of a general-purpose resist material using a diazonaphthoquinone compound.

Here, the resist material is preferably a chemically amplified positive resist material. Among the materials, examples of the alkali-soluble resin as the base polymer include polyhydroxystyrene or a derivative thereof. As the derivative of polyhydroxystyrene, one obtained by partially replacing the hydrogen atom of the hydroxyl group of polyhydroxystyrene with an acid-labile group is preferable, but a copolymer of hydroxystyrene can also be used. In the former case,
Acid-labile groups include tert-butyl, ter
t-butoxycarbonyl group, tetrahydropyranyl group,
Examples include a methoxymethyl group, a trimethylsilyl group, and a tert-butyldimethylsilyl group, and a tert-butyl group, a tert-butoxycarbonyl group, and a tetrahydropyranyl group are preferably used. In the latter case, the copolymer of hydroxystyrene includes a copolymer of hydroxystyrene and styrene, a copolymer of hydroxystyrene and tert-butyl acrylate, and a copolymer of hydroxystyrene and tert-butyl methacrylate. Examples include a polymer, a copolymer of hydroxystyrene and maleic anhydride, and a copolymer of hydroxystyrene and di-tert-butyl maleate.

The weight average molecular weight of polyhydroxystyrene or a derivative thereof is from 5,000 to 100,000.
When it is less than 5,000, the film formability and resolution may be poor, and when it exceeds 100,000, the resolution may be poor.

Further, as the dissolution inhibitor, a low molecular weight compound or polymer having at least one group decomposed by an acid (acid labile group) in the molecule is preferable. Specific examples of the low molecular weight compound include a bisphenol A derivative and a carbonate derivative. Particularly, a compound in which the hydroxyl group of bisphenol A is substituted with a tert-butoxy group or a tert-butoxycarbonyloxy group is preferable.

Examples of the polymer dissolution inhibitor include p-
Examples thereof include a copolymer of tert-butoxystyrene and tert-butyl acrylate and a copolymer of p-tert-butoxystyrene and maleic anhydride. In this case, the weight average molecular weight is preferably 5,000 to 10,000.

Further, the same acid generator as described above can be used as the acid generator, and the resist material can be prepared using a solvent that dissolves these components. Here, the mixing amount of these components can be a normal dose.

In order to form a resist pattern using the antireflection film material of the present invention, a known method can be adopted, for example, by performing a lithography process using a positive chemically amplified resist material shown in FIG. Can be. For example,
First, the antireflection film material of the present invention is spin-coated on a highly reflective substrate 1 of silicon, silicon oxide, silicon nitride, tungsten silicide, aluminum, or the like, and baked as needed (about 100 ° C., 120 seconds or less). To remove the residual solvent in the film) to form an anti-reflection layer 2, and a chemically amplified positive resist material is spin-coated and pre-baked on the anti-reflection layer 2 to form a resist layer 3. The resist layer 3 is exposed to a high energy ray such as a deep ultraviolet ray having a wavelength of 245 to 255 nm or a KrF excimer laser 4 having a wavelength of 248 nm by a reduction projection method in a desired pattern shape, that is, the portion A in FIG. , And then PEB (Post Exposure Ba)
ke), and the resist pattern 5 can be formed by a method of developing using a developing solution.
(D)).

[0045]

The antireflective coating material of the present invention, when used as an antireflective coating material under a chemically amplified resist film in pattern formation by the ARC method, has a required characteristic of "a complex refractive index of far ultraviolet rays. Since the imaginary part k, that is, the extinction coefficient k is 0.3 or more "and" does not cause tailing or notching "are satisfied, it is fine, has high dimensional accuracy, is simple and has high productivity, and additionally has Since it is soluble, it has a characteristic that it can be removed together with the resist film, and a resist pattern can be formed with good reproducibility.

[0046]

EXAMPLES The present invention will be specifically described below with reference to Synthesis Examples and Examples, but the present invention is not limited to the following Examples. First, a synthesis example of a polyimide soluble in an organic solvent and an aqueous alkali solution of the present invention will be described.

[Synthesis Example 1] In a flask equipped with a stirrer, a thermometer and a nitrogen purging apparatus, 4,4'-diamino 3,
5.31 g of 3'-dihydroxybiphenyl (0.025
mol), N-methyl-2-pyrrolidone 75 as a solvent
g of bis (3,4-dicarboxyphenyl) sulfone dianhydride 7.88 g (0.022 mol)
Was added so that the reaction temperature of the system did not exceed 30 ° C. Stirring is continued for 3 hours after the completion of the addition, and 0.89 g of phthalic anhydride is obtained.
(0.006 mol) was added, and the mixture was further stirred for 1 hour.
30 g of toluene was added, and the temperature of the solution was raised to 190 ° C. over 4 hours, and water produced as a by-product in this process was distilled off together with toluene. Further, stirring was continued at 190 ° C. for 5 hours to imidize the polyamic acid. The solution thus obtained is cooled, poured into methanol to precipitate a polyimide soluble in an organic solvent and an aqueous alkali solution, washed, dried under reduced pressure and dissolved in an organic solvent and an aqueous alkali solution generated. The polyimide was solid. The logarithmic viscosity was measured at 30 ° C. in N, N-dimethylformamide at a concentration of 0.5 g / 100 ml and found to be 0.23 dl / g.

Synthesis Example 2 5.41 g of 4,4′-diamino-3,3′-dihydroxybiphenyl as a diamine
(0.025 mol), 9.77 g of 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride as tetracarboxylic dianhydride (0.022 m
ol), 1.00 g (0.0 g) of 4-fluorophthalic anhydride.
06mol), but the logarithmic viscosity was 0.21 dl / g.

Synthesis Example 3 9.15 g (0.025 g) of 2,2-bis [4- (3-amino-4-hydroxyphenoxy) phenyl] hexafluoropropane as a diamine
mol), and bis (3,3) as tetracarboxylic dianhydride
4-dicarboxyphenyl) sulfone dianhydride 7.88
g (0.022 mol), 0.89 g of phthalic anhydride
(0.006 mol), but the logarithmic viscosity was 0.25 dl / g in the same manner as in Synthesis Example 1.

Synthesis Example 4 5.31 g of 3,3′-diamino-4,4′-dihydroxybiphenyl as diamine
(0.025 mol), 7.0 g (0.022 mol) of 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride as tetracarboxylic dianhydride, and 1.16 g (0.02 mol) of 4-nitrophthalic anhydride. 006 mol), except that the logarithmic viscosity was 0.22 dl / g.

[Synthesis Example 5] Bis [4-
(3-Amino-4-hydroxyphenoxy) phenyl]
11.60 g (0.025 mol) of sulfone and 7.88 g (0.022 mol of bis (3,4-dicarboxyphenyl) sulfone dianhydride as tetracarboxylic dianhydride
1) The procedure was performed in the same manner as in Synthesis Example 1 except that 0.89 g (0.006 mol) of phthalic anhydride was used. As a result, the logarithmic viscosity was 0.23 dl / g.

Synthesis Example 6 5.41 g of 4,4′-diamino-3,3′-dihydroxybiphenyl as diamine
(0.025 mol), 6.31 g (0.018 mol) of bis (3,4-dicarboxyphenyl) sulfone dianhydride as tetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) The procedure was performed in the same manner as in Synthesis Example 1 except that 1.78 g (0.004 mol) of hexafluoropropane dianhydride and 0.89 g (0.006 mol) of phthalic anhydride were used.
It was 20 dl / g.

Example 1 A positive type chemically amplified resist material having the following composition was used. 75 parts by weight of polyhydroxystyrene partially protected with a tert-butoxycarbonyl hydroxyl group 5 parts by weight of triphenylsulfonium trifluoromethanesulfonate 20 parts by weight of 2,2'-bis (4-tert-butoxycarbonyloxyphenyl) propane 1-ethoxy-2-propanol 500 parts by weight The following composition was used as the anti-reflective coating material. 5 parts by weight of polyimide soluble in organic solvent and aqueous alkali solution obtained in Synthesis Example 1 95 parts by weight of diethylene glycol dimethyl ether

A resist pattern was formed according to the lithography process shown in FIG. First, the antireflection film material is spin-coated on a highly reflective substrate 1 (silicon nitride).
An antireflection layer 2 of 1 μm was formed (FIG. 2A). In this case, baking at 100 ° C. for 90 seconds may be performed as needed.

Next, the positive type chemically amplified resist material is spin-coated on the anti-reflection layer 2 and
The resist layer 3 was formed in the range of 0.6 μm to 1.0 μm by pre-baking for 120 seconds.
(B)).

This was exposed using an excimer laser stepper (manufactured by Nikon Corporation, NSR-2005EX8A, NA-0.5) (FIG. 2C), and PEB at 90 ° C. for 60 seconds.
And development with an aqueous solution of 2.38% tetramethylammonium hydroxide, a positive pattern could be obtained (FIG. 2 (d)).

Observation of the dimensional variation of the obtained 0.3 μm line-and-space resist pattern revealed that the resist single-layer lithography was about ± 0.05 μm or more, and that the anti-reflection coating material was used. About ± 0.0 without skirting in lithography using
It could be reduced to 20 μm.

Example 2 As an antireflection film material, the one having the following composition was used. 5 parts by weight of polyimide soluble in organic solvent and aqueous alkali solution obtained in Synthesis Example 1 5 parts by weight of triphenylsulfonium trifluoromethanesulfonate 1 part by weight 94 parts by weight of diethylene glycol dimethyl ether Evaluation was made in the same manner as in Example 1 using the above antireflection film material. Observation of the dimensional variation of the obtained 0.30 μm line-and-space resist pattern revealed that the lithography using the above antireflection film material could reduce the size to about ± 0.015 μm without tailing.

Example 3 As an antireflection film material, the one having the following composition was used. 5 parts by weight of polyimide soluble in an organic solvent and an aqueous alkali solution obtained in Synthesis Example 2 95 parts by weight of diethylene glycol dimethyl ether 95% by weight of the above antireflection film material was evaluated in the same manner as in Example 1, and the obtained 0.30 μm Observation of the dimensional variation of the line-and-space resist pattern showed that the lithography using the anti-reflection film material could reduce the size to about ± 0.020 μm without tailing.

Example 4 The following composition was used as the antireflection film material. 5 parts by weight of polyimide soluble in organic solvent and aqueous alkali solution obtained in Synthesis Example 2 5 parts by weight of triphenylsulfonium trifluoromethanesulfonate 1 part by weight 94 parts by weight of diethylene glycol dimethyl ether Evaluation was made in the same manner as in Example 1 using the above antireflection film material. Observation of the dimensional variation of the obtained 0.30 μm line-and-space resist pattern revealed that the lithography using the above antireflection film material could reduce the size to about ± 0.015 μm without tailing.

Example 5 An antireflection film material having the following composition was used. Polyimide soluble in organic solvent and aqueous alkali solution obtained in Synthesis Example 3 4.5 parts by weight Bis (4-tert-butylphenyl) iodonium trifluoromethanesulfonate 0.5 parts by weight Diethylene glycol dimethyl ether 95 parts by weight 95% by weight When evaluation was performed in the same manner as in Example 1 using the film material, the dimensional variation of the obtained 0.30 μm line-and-space resist pattern was observed. It could be reduced to ± 0.015 μm.

Example 6 An antireflection film material having the following composition was used. 5 parts by weight of polyimide soluble in the organic solvent and aqueous alkali solution obtained in Synthesis Example 4 1 part by weight of pyrogallol trimesylate 94 parts by weight of diethylene glycol dimethyl ether 94 parts by weight Observation of the dimensional variation of the obtained 0.30 μm line and space resist pattern showed that the lithography using the antireflection film material could reduce the size to about ± 0.015 μm without tailing.

Example 7 As an antireflection film material, the one having the following composition was used. Polyimide soluble in organic solvent and aqueous alkali solution obtained in Synthesis Example 5 5 parts by weight Bis (4-tert-butylphenyl) iodonium trifluoromethanesulfonate 1 part by weight Diethylene glycol dimethyl ether 94 parts by weight Using the above antireflection film material As a result, when the dimensional variation of the obtained 0.30 μm line-and-space resist pattern was observed, the lithography using the above antireflection film material was performed at about ± 0.015 μm without tailing. Could be reduced.

Example 8 An antireflection coating material having the following composition was used. 5 parts by weight of polyimide soluble in organic solvent and alkali aqueous solution obtained in Synthesis Example 6 5 parts by weight of bis (4-tert-butylphenyl) iodonium trifluoromethanesulfonate 1 part by weight 94 parts by weight of diethylene glycol dimethyl ether Using the above antireflection film material As a result, when the dimensional variation of the obtained 0.30 μm line-and-space resist pattern was observed, the lithography using the above antireflection film material was performed at about ± 0.015 μm without tailing. Could be reduced.

[Brief description of the drawings]

FIG. 1A is a schematic diagram showing skirting, and FIG. 1B is a schematic diagram showing notching.

FIG. 2 is a schematic process diagram showing a method for forming a resist pattern using the antireflection film material of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Antireflection layer 3 Resist layer 4 High energy ray 5 Resist pattern 6 Pattern after etching

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Toshinobu Ishihara 28-1 Nishifukushima, Nishi-Jukumura, Nakakubijo-gun, Niigata Shin-Etsu Chemical Co., Ltd. Synthetic Technology Laboratory (56) References JP-A-1-281730 (JP A) JP-A-7-14762 (JP, A) JP-A-6-69170 (JP, A) (58) Fields studied (Int. Cl. ⁷ , DB name) C09D 1/00-201/10 C09K 3 / 00 G02B 1/00-1/12 CA (STN) REGISTRY (STN)

Claims (3)

(57) [Claims] An organic solvent comprising a polyimide which has a repeating unit represented by the following general formula (1) or (2) and is soluble in an organic solvent and an aqueous alkali solution, and an organic solvent. Anti-reflective coating material. Embedded image Embedded image 2. The method according to claim 1, wherein an acid generator or an organic acid is added.
The antireflection film material according to the above. 3. An antireflection film for forming a lower layer of a resist film made of a chemically amplified positive resist material.
Or the antireflection film material according to 2.