JP3248379B2 - Chemically amplified positive resist material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to deep ultraviolet rays,
It has high sensitivity to high energy rays such as lines, and can be patterned by developing with an alkaline aqueous solution.
The present invention relates to a chemically amplified positive resist material suitable for fine processing technology.

[0002]

2. Description of the Related Art LSI
With the demand for finer pattern rules in line with the higher integration and higher speed of light sources, light exposure, which is currently used as a general-purpose technology, is approaching the intrinsic resolution limit due to the wavelength of the light source. is there. In light exposure using a g-line (436 nm) or an i-line (365 nm) as a light source, a pattern rule of about 0.5 μm is limited, and the integration degree of an LSI manufactured using this is 16 Mbit DR.
AM equivalent. However, LSI prototypes have already been made at this stage, and there is an urgent need to develop further miniaturization techniques.

[0003] Against this background, 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.

A recently developed acid-catalyzed chemically amplified positive resist material (Japanese Patent Publication No. 2-27660,
Japanese Patent Application Laid-Open No. 3-27829) discloses a resist that is highly promising for deep-ultraviolet lithography, which uses a high-intensity KrF excimer laser as a light source for far-ultraviolet light, has high sensitivity, high resolution, and high dry etching resistance, and has excellent characteristics. Material.

[0005] Such a chemically amplified positive resist material comprises a two-component system comprising an alkali-soluble organic polymer and an acid generator, an alkali-soluble polymer, a dissolution inhibitor having an acid labile group, and an acid generator. Although a three-component type is known, it is desired to further improve its sensitivity and resolution.

Accordingly, an object of the present invention is to provide a chemically amplified positive resist material having high sensitivity and high resolution.

[0007]

The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that
Medium, the alkali-soluble resin, acid generator, to a chemically amplified positive resist composition comprising a solvent solution blocking agent further, partially hydroxyl groups represented further by the following general formula (1) as a dissolution enhancing agent protection When the blended polyhydroxystyrene compound is added, the dissolution rate contrast of the resist film is increased, especially the dissolution rate after exposure is increased, and it has a high resolution suitable for fine processing technology, and especially deep ultraviolet lithography. It has been found that a chemically amplified positive resist material which can exert a great effect in the above method can be obtained.

[0008]

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Wherein R is a tert-butyl group, te
Acid anxiety such as rt-butoxycarbonyl group, methoxymethyl group, isopropoxymethyl group, tetrahydropyranyl group, tetrahydrofuranyl group and trialkylsilyl group
It shows a fixed group , p / (p + q) is 0.1 or less, and the weight average molecular weight is less than 10,000. That is, the compound of the formula (1) causes microphase separation with the alkali-soluble resin, and in the patterning process of exposure, heating, and development, the dissolution rate of the matrix as the alkali-soluble resin is suppressed in the unexposed portion. In the exposed area, the acid labile groups of the alkali-soluble resin serving as the matrix are decomposed, so that the dissolution rate in the alkaline aqueous solution is accelerated, and the penetration of the alkaline aqueous solution into the film is increased. When the phase-separated compound of the formula (1) is rapidly dissolved, the apparently dissolving rate is rapidly increased because the alkali-soluble resin which has not been sufficiently dissolved is released into the alkaline aqueous solution in a block manner. From this, the compound of the above formula (1) is used as a dissolution accelerator, and greatly enhances the contrast of the dissolution rate of an exposed portion and an unexposed portion of the resist film in an aqueous alkali solution,
As a result, they have found that the resulting resist is a component of a chemically amplified positive resist having a new concept, which has not been heretofore exhibited, and has a high resolution, and have accomplished the present invention.

Accordingly, the present invention relates to (A) an organic solvent: 200 to 1,000 parts by weight, (B) an alkali-soluble resin: 100 parts by weight, (C) a dissolution inhibitor: 5 to 50 parts by weight, and (D) Acid generator: 1 to 20 parts by weight, (E) as a dissolution promoter, partially hydroxy-protected polyhydroxystyrene represented by the general formula (1): 5 to 5 parts
A chemically amplified positive resist composition comprising 50 parts by weight.

Hereinafter, the present invention will be described in more detail. The positive resist composition of the present invention contains a polyhydroxystyrene compound partially protected in a hydroxyl group represented by the following general formula (1) as a dissolution accelerator. It is characterized by doing.

[0012]

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(Wherein R is a tert-butyl group, te
Acid anxiety such as rt-butoxycarbonyl group, methoxymethyl group, isopropoxymethyl group, tetrahydropyranyl group, tetrahydrofuranyl group and trialkylsilyl group
It shows a fixed group , p / (p + q) is 0.1 or less, and the weight average molecular weight is less than 10,000. ) The polyhydroxystyrene compound in which the hydroxyl group is partially protected in the above formula (1) preferably has a p / (p + q) of 0.02 to 0.
08, the weight average molecular weight is 3,000-8,000. The compounding amount is 5 to 50 parts by weight per 100 parts by weight of the base polymer (alkali-soluble resin) of the resist material.
Parts by weight, preferably 10 to 30 parts by weight, and can be used alone or in combination of two or more. If the amount is less than 5 parts by weight, the resolution may not be improved. If the amount exceeds 50 parts by weight, the film thickness of the pattern may be reduced and the resolution may be reduced.

The resist composition of the present invention may be configured as a chemically amplified positive resist composition of the known three-component system, the solubility promoter is an organic Solvent, alkali-soluble resin as a base polymer, acid generator, further dissolved It can be incorporated into a resist material containing a blocking agent as a main component.

[0015] As the organic solvent medium, cyclohexanone, ketones such as methyl -2-n-amyl ketone,
Alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, Ethers such as ethylene glycol monoethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl-3-methoxypropionate, ethyl Esters such as -3-ethoxypropionate; one of these alone or two or more of them; Mixed and can be used.
Among these, diethylene glycol dimethyl ether and 1-ethoxy-2-propanol, which have the highest solubility of the acid generator in the resist component, are preferably used. Incidentally, the amount of the organic solvent medium is an alkali-soluble resin 1
The amount is 200 to 1000 parts by weight, preferably 400 to 800 parts by weight, per 100 parts by weight. If the amount is less than 200 parts, the compatibility is reduced and the film formability is poor. If the amount is more than 1000 parts, the resist film is formed into a thin film when formed, and may not be used.

The alkali-soluble resin as the base resin is not particularly limited, but some of the hydrogen atoms of the hydroxyl groups are acid labile groups such as tert-butoxycarbonyl, tert-butoxy, and tetrahydropyranyl groups. Partially substituted polyhydroxystyrene is preferred.
This alkali-soluble resin has a weight average molecular weight of 5,000.
0-100,000, preferably 10,000-50,
000 and a substitution rate of an acid labile group of 10 to 50 mol%, preferably 12 to 30 mol%, are suitably used. When the weight average molecular weight and the substitution ratio are out of the above ranges, the pattern profile may be deteriorated or the sensitivity may be deteriorated.

Further, as the acid generator, known ones can be used, and examples thereof include onium salts, sulfonic acid esters, diazosulfones and the like. Onium salts are preferred.
Examples of the onium salt include a triphenylsulfonium triflate derivative, a triphenylsulfonium tosylate derivative, and the like. The amount of the acid generator to be added is 1 to 20 parts by weight, preferably 2 to 10 parts by weight, based on 100 parts by weight of the alkali-soluble resin.

The material of the present invention further comprises a dissolution inhibitor.
You. As the dissolution inhibitor, those having one or more acid labile groups in the molecule are preferable. Known dissolution inhibitors can be used, and specifically, bisphenol A derivatives,
Phenolphthalein derivatives and the like are exemplified, and a compound in which a hydrogen atom of a hydroxyl group is substituted with a tert-butoxycarbonyl group is particularly preferably used. The addition amount of the dissolution inhibitor is from 5 to 50 per 100 parts by weight of the alkali-soluble resin.
Parts by weight, preferably 10 to 30 parts by weight.

Further, the resist composition of the present invention may contain a nitrogen-containing compound as an environmental stabilizer, a surfactant for improving coating properties, and a light absorbing composition for reducing the influence of irregular reflection from the substrate. The materials can be incorporated in conventional amounts.

In this case, examples of the nitrogen-containing compound include amine compounds and amide compounds having a boiling point of 150 ° C. or higher. Specifically, aniline, N-methylaniline, N, N-dimethylaniline, o-toluidine, m-
Toluidine, p-toluidine, 2,4-lutidine, quinoline, isoquinoline, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, 2-pyrrolidone, N- Methylpyrrolidone, imidazole, α-picoline, β-picoline, γ-picoline, o-aminobenzoic acid, m-aminobenzoic acid, p-aminobenzoic acid, 1,2-phenylenediamine, 1,3-
Phenylenediamine, 1,4-phenylenediamine, 2
And triazine compounds such as -quinolinecarboxylic acid, 2-amino-4-nitrophenol, and 2- (p-chlorophenyl) -4,6-trichloromethyl-s-triazine. Among these, in particular, pyrrolidone, N-methylpyrrolidone, o-aminobenzoic acid, m-aminobenzoic acid, p-aminobenzoic acid, 1,2-phenylenediamine, 1,3-phenylenediamine, 1,4-phenylene Diamines are preferably used.

Examples of the surfactant include perfluoroalkyl polyoxyethylene ethanol, fluorinated alkyl ester, perfluoroalkyl amine oxide, and perfluoroalkyl EO adduct. Examples of the light absorbing material include diaryl sulfoxide, Examples include diaryl sulfone, 9,10-dimethylanthracene, 9-fluorenone and the like.

The formation of a pattern using the positive resist composition of the present invention can be carried out by using a known lithography technique, for example, by spin-coating on a silicon wafer and forming a 0.5 to 1. After coating at 5 μm and pre-baking at 80 to 120 ° C., irradiating with light energy rays such as far ultraviolet rays, electron beams, X-rays, etc.
Post-exposure bake (PEB) at 100 ° C. for 60 to 120 seconds, and then development with an aqueous alkali solution can be performed. The material of the present invention is particularly suitable for fine patterning using 254 to 193 nm deep ultraviolet light and an electron beam among high energy rays.

[0023]

As described above, the chemically amplified positive resist composition of the present invention is sensitive to high energy rays such as far ultraviolet rays, electron beams and X-rays, especially KrF excimer laser, and has excellent sensitivity, resolution and plasma etching resistance. In addition, it has high resolution suitable for fine processing technology having excellent heat resistance of the resist pattern, and has high practicality.

[0024]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples. All parts in each example are parts by weight.

Examples 1 to 10 and Comparative Examples 1 to 5 The hydroxyl groups represented by the following formulas (Polym 1 to 3) are partially protected by tert-butoxycarbonyl, tert-butoxy and tetrahydropyranyl groups, respectively. Polyhydroxystyrene, an acid generator represented by the following formula (PAG1-4), a dissolution inhibitor represented by the following formula (DRI1) or (DRI2), and (DRA1)
6) A compound having a phenolic OH group (dissolution promoter) shown in Table 1 was dissolved in diethylene glycol dimethyl ether with the composition shown in Table 1, a resist composition was prepared, and each composition was further filtered with a 0.2 μm Teflon filter. A resist solution was prepared by filtration.

The obtained resist solution was spin-coated on a silicon wafer and applied to a thickness of 0.8 μm. Next, the silicon wafer was baked at 100 ° C. for 120 seconds using a hot plate.

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

The obtained resist pattern was evaluated as follows. The results are shown in Tables 1 and 2.

Evaluation method: First, the sensitivity (Eth) was determined. Next, a 0.35 μm line and space of 1: 1
And the minimum line width of the separated lines and spaces at this exposure amount was taken as the resolution of the evaluation resist. The shape of the resolved resist pattern was observed using a scanning electron microscope.

From the results shown in Tables 1 and 2, it was confirmed that the chemically amplified positive resist composition of the present invention had good sensitivity and high resolution.

[0031]

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[0032]

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[0033]

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[0034]

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(1) R: tert-butoxycarbonyl group p / (p + q): 0.02 (DRA1) Weight average molecular weight: 8,000 (2) R: tert-butoxycarbonyl group p / (p + q): 0. 05 (DRA2) Weight average molecular weight: 3,000 (3) R: tert-butyl group p / (p + q): 0.02 (DRA3) Weight average molecular weight: 8,000 (4) R: tert-butyl group p / (P + q): 0.05 (DRA4) Weight average molecular weight: 3,000 (5) R: methoxymethyl group p / (p + q): 0.03 (DRA5) Weight average molecular weight: 8,000 (6) R: tetrahydro Pyranyl group p / (p + q): 0.08 (DRA6) Weight average molecular weight: 3,000

[0036]

[Table 1]

[0037]

[Table 2]

Continuing on the front page (72) Inventor Toshinobu Ishihara 28-1 Nishifukushima, Nishifukushima, Nakatsukushi-gun, Niigata Pref. Shin-Etsu Chemical Co., Ltd. 28-1 Shin-Etsu Chemical Co., Ltd., Synthetic Technology Research Laboratory (72) Inventor Katsuya Takemura 28-1, Nishifukushima, Oku-ku, Nakakushiro-gun, Niigata Prefecture Shin-Etsu Chemical Co., Ltd. Synthetic Technology Research Laboratory (72) Inventor Keijun Tanaka Tokyo Nippon Telegraph and Telephone Corporation, 1-1-6 Uchisaiwai-cho, Chiyoda-ku, Tokyo (72) Inventor Yoshio Kawai 1-6-1, Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (56) References 217251 (JP, A) JP-A-4-134345 (JP, A) JP-A-6-289615 (JP, A) JP-A-6-236037 (JP, A) JP-A-8-15864 (JP, A) JP-A-6-266106 (JP, A) JP-A-7-92671 (JP, A) JP-A-7-199468 (JP, A) ) (58) investigated the field (Int.Cl. ^7, DB name) G03F 7/00 - 7/42

Claims (4)

(57) [Claims] (A) an organic solvent: 200 to 1,000 parts by weight, (B) an alkali-soluble resin: 100 parts by weight, (C) a dissolution inhibitor: 5 to 50 parts by weight, (D) an acid generator: 1 to 20 parts by weight, (E) as a dissolution promoter, a partially hydroxy-protected polyhydroxystyrene represented by the following general formula (1):
5 to 50 parts by weight (Wherein R represents an acid labile group, p / (p + q) is 0.1 or less, and the weight average molecular weight is less than 10,000). Positive resist material. 2. An acid labile group represented by R in the general formula (1) is t
tert-butyl group, tert-butoxycarbonyl group,
Methoxymethyl group, iso-propoxymethyl group, a tetrahydropyranyl group, a chemically amplified positive resist composition according to claim 1 Symbol placement are those selected from tetrahydrofuranyl group and trialkylsilyl group. 3. The component (B) is a polyhydroxystyrene having a weight average molecular weight of 10,000 to 50,000 in which a hydrogen atom of a hydroxyl group is substituted by an acid labile group at a substitution rate of 10 to 50 mol%. Item 3. The chemically amplified positive resist material according to Item 1 or 2 . 4. The composition according to claim 1, further comprising a nitrogen-containing compound.
4. The chemically amplified positive resist material according to any one of 3 .