JPH0978031A - Reflection-protecting film material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a reflection-protecting film material having high dimensional accuracy and productivity, capable of being removed together with a resist film and forming a resist pattern in good reproducibility and useful for underlayer reflection-protecting films of chemical amplification type resist films by compounding contain a specific polyimide and an organic solvent. SOLUTION: This reflection-protecting film material contains (A) a polyimide soluble in an organic solvent or an aqueous alkaline solution e.g. a polymer having 0.01-5dl/g logarithmic viscosity and expressed by the formula [R is H, a halogen, a 1-10C alkyl or nitro; Y is CH2 , SO2 , O, C(CH3 )2 , C(CF3 )2 or CO; X is Y or OC6 H4 O; (m) and (k) are each 0 or 1; (n) is the degree of polymerization]}, (B) an organic solvent and, if needed, (C) an acid generator or an organic acid.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention has a high sensitivity to high-energy rays such as deep ultraviolet rays, electron beams, and X-rays, and is suitable for a fine processing technique capable of forming a pattern by developing with an alkaline aqueous solution. The present invention relates to an antireflection film material effective for forming an underlayer of a chemically amplified resist film.

[0002]

2. Description of the Related Art LSI to be Solved
With the higher integration and higher speed, deep-ultraviolet lithography is considered promising as a next-generation microfabrication technology. The deep-UV lithography can also process 0.3 to 0.4 μm, and when a resist material having low light absorption is used, it becomes possible to form a pattern having a side wall that is almost vertical to the substrate. Further, in recent years, a technique using a KrF excimer laser as a light source of far ultraviolet rays has been attracting attention, and a resist material having low light absorption and high sensitivity is required for its use as a mass production technique.

From such a point, a chemically amplified positive resist material which has been developed in recent years using an acid as a catalyst (Japanese Patent Publication No. 2-27).
660, JP-A-63-27829, U.S. Pat. Nos. 4,491,628, and 5,310,619) have excellent sensitivity, resolution, and dry etching resistance and are excellent. This resist material is particularly promising for deep ultraviolet lithography because of its characteristics.

However, in deep ultraviolet lithography, the standing wave (S
The dimensional accuracy of the resist image decreases due to the effects of tanning wave), the optical interference due to the change of the resist layer thickness at the step portion when there is a step on the substrate, and the effect of halation from the step portion. This causes a problem that the pattern size cannot be processed accurately.

Further, in the chemically amplified resist material, when the substrate dependence of the pattern profile is a nitride film, the positive resist material is in contact with the resist pattern 5 on the substrate 1 as shown in FIG. 1 (A). Hemming on the part (Foot
ing), the negative resist material has 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 (Hasushima et al., Spring 1994). Proceedings of the Japan Society of Applied Physics, p566, 29a, MB-10 / Fukushima et al., 199
Proceedings of the 4th Spring Society of Applied Physics, p566, 29p,
MB-1). This is believed to occur because the N—H bond in the nitride film deactivates the acid at the chemically amplified resist film-nitride film substrate interface.

Therefore, as a pattern forming method for solving the above problems, an ARC (antireflection film formed in a resist lower layer) method has been proposed (BW Dudley.e).
t. al. , SPIE Vol. 1672 Advance in Resist Technology and Processing (Advances in Resist Tec)
hology and Processing) I
X, 638 (1992). / Tani et al., Proceedings of the 1994 Spring Society of Applied Physics, p567, 29p, MB-4). As the ARC method, a method of using an inorganic film or an organic film as an antireflection film is generally used, but the ARC method using an inorganic film is performed by sputtering or CVD (chemical vapor deposition) to form an inorganic film. However, there is a problem in that the equipment for that purpose is very expensive.

The ARC method using an organic film has an advantage that throughput is good because an apparatus for forming an organic film is only an inexpensive coater and the processing time is shorter than that of an inorganic film. UV rays (wavelength 245-25
(5 nm) In lithography, it is a required characteristic for processing into an accurate pattern size. "The imaginary part k of the complex index of refraction in deep UV, that is, the extinction coefficient k is 0.3 or more."
In addition, there is still a problem that there is no material satisfying the condition of "no tailing or notching".
Further, the antireflection film material (see Japanese Patent Publication No. 6-12452) for a general-purpose resist material using a diazonaphthoquinone compound, which is not the currently known chemically amplified resist material, uses a polyamic acid as a main component and forms a film. After formation, the extinction coefficient k is satisfied because the method of chemically converting into polyimide by performing heat treatment at 140 ° C. or higher for 30 minutes or longer is satisfied, but like the nitride film, the film is also subjected to heat treatment after heat treatment. The NH bond in the above (amine residue and terminal amine residue in the polyamic acid main chain) cannot be completely converted to an imide group which is an inactive group, and ammonia is generated by heating at a high temperature. Not suitable because it causes notching. Further, the general-purpose resist antireflective coating material using another diazonaphthoquinone compound (US Pat. No. 5,234,990) uses polysulfone as a main component, so that it does not cause tailing or notching, The value of the extinction coefficient k does not satisfy the required value.

The present invention has been made in view of the above circumstances, and is a lower layer of a chemically amplified resist film capable of forming a resist pattern that is fine, has high dimensional accuracy, is simple, has high productivity, and has good 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 Modes for Carrying Out the Invention As a result of earnest studies for achieving the above-mentioned object, the present inventor has found that far-ultraviolet rays, electron beams, high energy rays such as X-rays, especially far-ultraviolet rays ( Having a high sensitivity to a wavelength of 245 to 255 nm and capable of forming a pattern by developing with an alkaline aqueous solution and being suitable as an antireflection film material used as an underlayer of a chemically amplified resist film suitable for a fine processing technique by an ARC method, By blending a polyimide soluble in a solvent and an aqueous alkaline solution, particularly a polymer having a repeating unit represented by the following general formula (1) or (2) as a main component, the above-mentioned required characteristics in deep ultraviolet lithography can be obtained. A certain "imaginary part k of the complex refractive index in the deep ultraviolet,
That is, it was found that the material can be a material satisfying the conditions of "extinction coefficient k of 0.3 or more" and "no 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 antireflection layer is formed of an antireflection film material whose main component is polyimide soluble in an organic solvent and an alkaline aqueous solution, the extinction coefficient k becomes 0.3 or more, and the resist -Since the reflectance of light at the interface of the antireflection layer can be suppressed and the transmittance can be significantly reduced, it is possible to suppress the variation in the pattern dimension due to standing waves and halation in the resist layer as compared with the resist single layer. Therefore, it is possible to improve the dimensional accuracy of the resist image, and in particular, by modifying the terminal amine residue with a phthalic anhydride derivative or the like, the NH bond can be removed, resulting in tailing and notching. In addition, the process is simpler because it does not require heat treatment at a high temperature of 140 ° C. or higher for 30 minutes or longer, for a long time. 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, which has the advantage of shortening the process.

Further, by adding an acid generator or an organic acid to the above antireflection film material for the purpose of supplying an acid to the resist film-antireflection layer interface in the exposed portion, the dimensional accuracy of the resist image is further improved. It was also found that the above can be improved, and the present invention has been completed.

Therefore, the present invention provides an antireflection film material comprising a polyimide soluble in an organic solvent and an alkaline aqueous solution, and an organic solvent.

The present invention will be described in more detail below. As a polyimide soluble in an organic solvent and an alkaline aqueous solution, which are the main components of the antireflection film material of the present invention, a polyimide soluble in a spin coatable organic solvent described below is used. Various polyimides can be used so long as they have a logarithmic viscosity range of 0.01 to 5 dl / g, especially 0.05 to 1 dl / g.
Are preferred. Logarithmic viscosity range is 0.01 dl / g
If it does not meet the requirements, it may not be possible to form a film, and 5 dl / g
If it exceeds, the solution has a high viscosity and becomes difficult to handle.

The logarithmic viscosity is such that the polyimide concentration is 0.5.
It can be determined by the following formula from the result of measurement using a solution of g / 100 ml DMF (N, N-dimethylformamide) under the measurement condition of 30 ° C.

[0017]

[Equation 1]

The above-mentioned polyimide soluble in an organic solvent and an aqueous alkaline solution is preferably a polymer having a repeating unit represented by any one of the following general formulas (1) and (2).

[0019]

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[0020]

[Chemical 6]

The polyimides represented by the general formulas (1) and (2) are represented by the tetracarboxylic dianhydride represented by the following general formula (3) and the following general formula (4) or (5). A polyamic acid obtained 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 is prepared, and then heat imidized according to a conventional method. It can be produced by performing imide conversion.

[0022]

[Chemical 7]

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'-benzophenone tetracarboxylic acid 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 can be mentioned, and these tetracarboxylic dianhydrides can be used alone or in combination of two or more.

Further, specific examples of the aromatic diamine having a phenolic hydroxyl group represented by the above general formulas (4) and (5) include bis (3-amino-4-hydroxyphenyl) ether and bis (4-). 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 are used, and one of these aromatic diamines is used alone or in combination of two or more. can do.

As the monovalent organic group for modifying the terminal amino group, succinic anhydride derivatives of aliphatic hydrocarbons can be used, but in order to increase the k value, the above general formula (6) Aromatic hydrocarbons represented by) are preferable.
Specifically, phthalic anhydride, 4-methylphthalic anhydride,
4-fluorophthalic anhydride, 4-nitrophthalic anhydride,
4-chlorophthalic anhydride, 4-bromophthalic anhydride, etc. can be mentioned.

The equations (3), (4) or the equation (5),
The reaction molar ratio of the compound of (6) is 100: 130: 60-
The ratio is preferably 100: 102: 4.

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

In the case of dehydration and ring closure by heating, a polyimide can be produced by azeotroping water by-produced by imidization in the presence of an organic solvent which forms an azeotropic mixture with water, such as toluene, xylene and chlorobenzene. it can. The reaction temperature is 150 to 400 ° C., preferably 1
It is 80-350 degreeC. At a temperature lower than 150 ° C, imidization does not proceed partially, and at a temperature higher than 400 ° C, decomposition may occur. The reaction time is 30 seconds to 10 hours, preferably 5 minutes to 5 hours. After the completion of the reaction, it is preferable to use it after pouring it into a large amount of water or a poor solvent to precipitate the polymer, washing and drying it to obtain a solid.

The amount of the polyimide soluble in the organic solvent and the alkaline aqueous solution is such that the thickness of the antireflection film layer is 100 to 20.
In order to set it to 00 Å (0.01 to 0.2 μm), 1 to 20% (weight%, the same below) of the whole is desirable, especially 3 to 10% is desirable, and if it is less than 1%, the film thickness becomes less than 100 Å The antireflection effect may be reduced, and if it exceeds 20%, the fluidity of the solution may be deteriorated, and it may be difficult to form a uniform coating film.

Next, as the organic solvent, those capable of spin coating are desirable, for example, ketones such as cyclohexanone, ethers such as propylene glycol dimethyl ether and diethylene glycol dimethyl ether,
Examples thereof include esters such as methyl-3-methoxypropionate and ethyl-3-ethoxypropionate, and these can be used alone or in combination of two or more. Among these, polyimide that is soluble in an organic solvent and an aqueous alkaline solution, cyclohexanone, which has the highest solubility of the acid generator, diethylene glycol dimethyl ether, and methyl-3-methoxypropionate are preferably used.

It is preferable to add an acid generator to the antireflection film material of the present invention for the purpose of supplying an acid to the resist film-antireflection layer interface in the exposed area.

Examples of the acid generator include onium salts and pi
Rogalol trimesylate derivative, oxime sulfonic acid
Derivative, 2,6-dinitrobenzyl sulfonic acid derivative,
Diazonaphthoquinonesulfonic acid derivative, 2,4-bisto
Lichloromethyl-6-aryl-1,3,5-triazi
Derivatives, α, α'-bisarylsulfonyldiazomes
Examples include tan derivatives, but especially the following general
The onium salt represented by the formula (7) is preferably used. (R ’)_mMY ... (7) (In the formula, R ′ Is the same or different unsubstituted or substituted aromatic
Group, M is sulfonium or iodonium, Y is substituted or
It is an unsubstituted alkyl or aryl sulfonate. m
Is 2 or 3. )

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

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 blended is preferably 1 to 100 parts, and more preferably 3 to 25 parts, per 100 parts (parts by weight, hereinafter the same) of the polyimide soluble in an organic solvent and an alkaline aqueous solution.
If the amount is less than 1 part, the acid may not be sufficiently supplied to the resist film-antireflection layer interface in the exposed part, and the effect of the addition of the acid generator may be scarce. If the amount exceeds 100 parts, the extinction coefficient k may be 0. There are cases where the value of 3 is not satisfied.

Further, in the present invention, a surfactant may be added to improve the coating property. In addition, depending on the reflectance characteristics of the substrate, deep ultraviolet rays (wavelength 245-255n
It is also possible to add at least one kind of light absorbing agent having a molar absorption coefficient in the m) region of 20,000 or more. Further, in order to supply an acid to the antireflection layer, an organic acid such as acetic acid, propanoic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, trifluoroacetic acid can be added. The amounts of the surfactant, the light absorber and the organic acid to be added can be normal amounts within a range that does not impair the effects of the present invention.

The antireflection film material of the present invention can be obtained by mixing the above components, and has a wavelength of 245 to 255.
It is most suitable for fine patterning with deep ultraviolet rays of nm and a KrF excimer laser of wavelength 248 nm, but of course there is no problem even 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 that is the base polymer include polyhydroxystyrene and derivatives 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,
Examples of acid labile groups include tert-butyl group and ter
t-butoxycarbonyl group, tetrahydropyranyl group,
Examples thereof 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 thereof include polymers, copolymers of hydroxystyrene and maleic anhydride, and copolymers of hydroxystyrene and di-tert-butyl maleate.

The weight average molecular weight of polyhydroxystyrene or its derivative is 5,000 to 100,000.
If it is less than 5,000, the film-forming property and the resolution may be inferior, and if it exceeds 100,000, the resolution may be inferior.

Further, the dissolution inhibitor is preferably a low molecular weight compound or polymer having at least one group capable of decomposing by an acid (acid labile group) in the molecule. Specific examples of the low molecular weight compound include bisphenol A derivatives and carbonic acid ester derivatives, and a compound in which the hydroxyl group of bisphenol A is substituted with a tert-butoxy group or a tert-butoxycarbonyloxy group is particularly preferable.

Examples of polymer dissolution inhibitors 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.

Furthermore, the same acid generator as the above-mentioned acid generator can be blended, and the resist material can be prepared by using a solvent which dissolves these components. Here, the compounding amount of these components can be a usual dose.

To form a resist pattern using the antireflection film material of the present invention, a known method can be adopted, for example, a lithographic process using a positive chemically amplified resist material shown in FIG. You can For example,
First, the antireflection film material of the present invention is spin-coated on a highly reflective substrate 1 made of silicon, silicon oxide, silicon nitride, tungsten silicide, aluminum, etc., and if necessary, baked (about 100 ° C., 120 seconds or shorter heating). To remove the residual solvent in the film) to form an antireflection layer 2, and a chemically amplified positive resist material is spin-coated on the antireflection layer 2 and prebaked to form a resist layer 3. The resist layer 3 is exposed to deep ultraviolet rays having a wavelength of 245 to 255 nm or high energy rays such as a KrF excimer laser 4 having a wavelength of 248 nm in a desired pattern shape by a reduction projection method, that is, the portion A in FIG. 2 (c) is exposed. , And then PEB (Post Exposure Ba
The resist pattern 5 can be formed by carrying out ke) and developing with a developing solution (FIG. 2).
(D)).

[0045]

INDUSTRIAL APPLICABILITY When the antireflection film material of the present invention is used as an antireflection film material for a lower layer of a chemically amplified resist film in pattern formation by the ARC method, it has a required characteristic of "a complex refractive index in deep ultraviolet rays. Since the condition that the imaginary part k, that is, the extinction coefficient k is 0.3 or more "and that" no tailing or notching is caused "is satisfied, it is fine and has high dimensional accuracy, is simple and highly productive, 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 described in detail below with reference to synthetic 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 alkaline aqueous solution of the present invention will be shown.

[Synthesis Example 1] 4,4'-diamino 3, in a flask equipped with a stirrer, a thermometer and a nitrogen purging device.
5.41 g of 3'-dihydroxybiphenyl (0.025
mol), N-methyl-2-pyrrolidone 75 as a solvent
g was charged, and 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. After the addition was completed, stirring was continued for 3 hours, and 0.89 g of phthalic anhydride
(0.006 mol) was added, and the mixture was further stirred for 1 hr.
30 g of toluene was added, the temperature of this solution was raised to 190 ° C. over 4 hours, and water by-produced 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 and poured into methanol to precipitate a polyimide soluble in an organic solvent and an alkaline aqueous solution, which is washed and dried under reduced pressure to be soluble in an organic solvent and an alkaline aqueous solution. The polyimide was solid. When the logarithmic viscosity was measured in N, N-dimethylformamide at 30 ° C. and a concentration of 0.5 g / 100 ml, it was 0.23 dl / g.

[Synthesis Example 2] 5.41 g of 4,4'-diamino-3,3'-dihydroxybiphenyl as a diamine
(0.025 mol), as a tetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride 9.77 g (0.022 m)
ol), 4-fluorophthalic anhydride 1.00 g (0.0
When the same procedure as in Synthesis Example 1 was carried out except that (06 mol) was used, the logarithmic viscosity was 0.21 dl / g.

[Synthesis Example 3] 2,15-bis [4- (3-amino-4-hydroxyphenoxy) phenyl] hexafluoropropane as a diamine 9.15 g (0.025)
mol) and bis (3,4 as tetracarboxylic dianhydride
4-dicarboxyphenyl) sulfone dianhydride 7.88
g (0.022 mol), phthalic anhydride 0.89 g
The procedure of Synthesis Example 1 was repeated except that (0.006 mol) was used, and the logarithmic viscosity was 0.25 dl / g.

Synthesis Example 4 5,41 g of 3,3'-diamino-4,4'-dihydroxybiphenyl as diamine
(0.025 mol), as tetracarboxylic dianhydride, 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride 7.0 g (0.022 mol), 4-nitrophthalic anhydride 1.16 g (0. When the same procedure as in Synthesis Example 1 was carried out except that (006 mol) was used, the logarithmic viscosity was 0.22 dl / g.

[Synthesis Example 5] Bis [4-] as diamine
(3-Amino-4-hydroxyphenoxy) phenyl]
11.60 g (0.025 mol) of sulfone, 7.88 g (0.022mo) of bis (3,4-dicarboxyphenyl) sulfone dianhydride as tetracarboxylic dianhydride.
l) and phthalic anhydride 0.89 g (0.006 mol) were used, and 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), bis (3,4-dicarboxyphenyl) sulfone dianhydride 6.31 g (0.018 mol) as tetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) Hexafluoropropane dianhydride 1.78 g (0.004 mol) and phthalic anhydride 0.89 g (0.006 mol) were used in the same manner as in Synthesis Example 1 except that the logarithmic viscosity was 0.
It was 20 dl / g.

Example 1 As the positive chemically amplified resist material, the following composition was used. Polyhydroxystyrene partially protected with a tert-butoxycarbonyl group 75 parts by weight Triphenylsulfonium trifluoromethanesulfonate 5 parts by weight 2,2′-bis (4-tert-butoxycarbonyloxyphenyl) propane 20 parts by weight 1-Ethoxy-2-propanol 500 parts by weight The antireflection film material having the following composition was used. Polyimide soluble in organic solvent and aqueous alkaline solution obtained in Synthesis Example 1 5 parts by weight Diethylene glycol dimethyl ether 95 parts by weight

A resist pattern was formed according to the lithography process shown in FIG. First, the above antireflection film material is spin-coated on the high reflection substrate 1 (silicon nitride),
An antireflection layer 2 having a thickness of 1 μm was formed (FIG. 2A). In this case, you may bake at 100 degreeC for 90 second as needed.

Then, the positive chemically amplified resist material is spin-coated on the antireflection layer 2 and the temperature is raised to 100 ° C.
The resist layer 3 was formed in the range of 0.6 μm to 1.0 μm by prebaking for 120 seconds (see FIG. 2).
(B)).

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

Observing the dimensional variation of the obtained 0.3 μm line-and-space resist pattern, it was about ± 0.05 μm or more in the resist single-layer lithography, and a skirt was generated. Approximately ± 0.0 without hem in lithography using
It could be reduced to 20 μm.

Example 2 The following composition was used as the antireflection film material. Polyimide soluble in organic solvent and alkaline aqueous solution obtained in Synthesis Example 1 5 parts by weight Triphenylsulfonium trifluoromethanesulfonate 1 part by weight Diethylene glycol dimethyl ether 94 parts by weight Evaluation was made in the same manner as in Example 1 using the above antireflection film material. As a result, observing the dimensional variation of the obtained 0.30 μm line-and-space resist pattern, it was possible to reduce to about ± 0.015 μm without tailing in lithography using the above antireflection film material.

Example 3 As the antireflection film material, the material having the following composition was used. Polyimide soluble in organic solvent and alkaline aqueous solution obtained in Synthesis Example 2 5 parts by weight Diethylene glycol dimethyl ether 95 parts by weight When the same evaluation as in Example 1 was carried out using the above antireflection film material, the obtained 0.30 μm By observing the dimensional variation of the resist pattern in the line and space, it was possible to reduce to about ± 0.020 μm in the lithography using the antireflection film material without tailing.

[Example 4] As the antireflection film material, the following composition was used. Polyimide soluble in organic solvent and alkaline aqueous solution obtained in Synthesis Example 2 5 parts by weight Triphenylsulfonium trifluoromethanesulfonate 1 part by weight Diethylene glycol dimethyl ether 94 parts by weight Evaluation in the same manner as in Example 1 using the above antireflection film material Then, observing the dimensional variation of the obtained 0.30 μm line-and-space resist pattern, it was possible to reduce to about ± 0.015 μm without tailing in lithography using the above antireflection film material.

Example 5 As the antireflection film material, the following composition was used. Polyimide soluble in organic solvent and aqueous alkaline 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 The above antireflection When evaluation was performed in the same manner as in Example 1 using the film material, observing the dimensional variation of the obtained 0.30 μm line-and-space resist pattern, it was found that the lithography using the antireflection film material described above was performed without tailing. It was possible to reduce to ± 0.015 μm.

Example 6 As the antireflection film material, the material having the following composition was used. Polyimide soluble in organic solvent and alkaline aqueous solution obtained in Synthesis Example 4 5 parts by weight Pyrogallol trimesylate 1 part by weight Diethylene glycol dimethyl ether 94 parts by weight It was evaluated in the same manner as in Example 1 using the above antireflection film material. Observing the dimensional variation of the resist pattern having a line-and-space of 0.30 μm, it was possible to reduce to about ± 0.015 μm without tailing in lithography using the above antireflection film material.

Example 7 As the antireflection film material, the material having the following composition was used. Polyimide soluble in organic solvent and alkaline aqueous 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 of evaluation in the same manner as in Example 1, observing the dimensional variation of the obtained 0.30 μm line-and-space resist pattern, lithography using the antireflection film material described above performed about ± 0.015 μm without tailing. Could be reduced to.

Example 8 As the antireflection film material, the following composition was used. Polyimide soluble in organic solvent and alkaline aqueous solution obtained in Synthesis Example 6 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 of evaluation in the same manner as in Example 1, observing the dimensional variation of the obtained 0.30 μm line-and-space resist pattern, lithography using the antireflection film material described above performed about ± 0.015 μm without tailing. Could be reduced to.

[Brief description of drawings]

FIG. 1A is a schematic view showing a hem and FIG. 1B is a schematic view 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]

 1 substrate 2 antireflection layer 3 resist layer 4 high energy ray 5 resist pattern 6 pattern after etching

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G02B 1/11 G02B 1/10 A

Claims (4)

[Claims] 1. An antireflection film material comprising an organic solvent and a polyimide soluble in an alkaline aqueous solution, and an organic solvent. 2. The antireflection film material according to claim 1, wherein a polyimide soluble in an organic solvent and an aqueous alkaline solution has a logarithmic viscosity range of 0.01 to 5 dl / g. 3. The antireflection film material according to claim 1, wherein the polyimide soluble in an organic solvent and an alkaline aqueous solution is a polymer having a repeating unit represented by the following general formula (1) or (2). . Embedded image Embedded image 4. An acid generator or an organic acid is added.
4. The antireflection film material according to any one of items 1 to 3.