Radiation imagery chemistry: process – composition – or product th – Diazo reproduction – process – composition – or product – Composition or product which contains radiation sensitive...
Reexamination Certificate
1999-10-22
2003-04-08
Chu, John S. (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Diazo reproduction, process, composition, or product
Composition or product which contains radiation sensitive...
C430S270100, C430S905000
Reexamination Certificate
active
06544712
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a negative working resist material. More particularly, it relates to a negative working resist composition suitable to fine processing with radiations such as ultraviolet rays, far ultraviolet rays, excimer (e.g., KrF or ArF) laser beams, X-rays, and electron beams.
BACKGROUND OF THE INVENTION
In the manufacture of electronic components such as semiconductor devices and liquid crystal display devices, processing technology has recently gained in fineness. With this tendency, it has been demanded for the resist to be used to have higher resolution and higher sensitivity to form a resist pattern with a satisfactory profile. Under such circumstances, attention is paid to a chemically amplified resist in which reaction which changes the solubility of the resist in a developer is caused by catalysis of an acid generated with irradiation of radiation, and a number of chemically amplified negative working resist compositions are proposed.
Photolithography is adopted in manufacturing electronic components by use of the chemically amplified negative working resist composition. That is, a chemically amplified negative working resist is applied to a substrate, such as a silicon wafer, irradiated with a radiation through a mask pattern, and developed to form a resist pattern. The substrate is then etched with the resist pattern as a protective film.
There is a tendency in the photolithography to use radiations having short wavelengths, such as UV rays, deep UV rays, and excimer (e.g., KrF or ArF) laser beams. Use of electron rays and X-rays has also been studied intensively. In order for a chemically amplified negative working resist composition to be sensitive to such short-wavelength radiations to form a satisfactory resist pattern, it is important that each component making up the resist composition shows small absorption of the radiation. From this viewpoint, novolak resins that have been used conventionally are impractical because of their large radiation absorption, and polvinylphenol resins having a small radiation absorption have come to be used.
Chemically amplified negative working resist compositions containing a polyvinylphenol resin as a resinous component are disclosed in JP-A-1-293339, JP-A-2-15270, and JP-A-4-163552, but any of them has insufficient resolution. To improve resolution, JP-A-7-238196 proposes to use, as an alkali-soluble resin, a 4-hydroxystyrene-styrene copolymer having a styrene content of 5 to 20 mol % and a weight average molecular weight of 6000 to 25,000.
However, the resist pattern formed of the chemically amplified resist composition according to JP-A-7-238196 is inferior in contrast, and its profile is not satisfactory. In order to overcome these disadvantages, JP-A-7-295220 teaches a chemically amplified negative working photoresist composition comprising an alkali-soluble resin containing at least one of partially alkyl etherified polyvinylphenol and partially alkyl etherified hydrogenated polyvinylphenol, a photosensitive acid generator containing at least one sulfonic ester of an N-hydroxyimide compound, and a crosslinking agent. While this composition exhibits improved resolution and an improved profile, the resist characteristics are liable to change with time, which has been a great problem in practical use.
SUMMARY OF THE INVENTION
Accordingly, an object of the invention is to provide a practical negative working resist composition which is excellent in resolution, profile, and aging stability.
In the light of the above-described circumstances, the present inventors have conducted extensive investigations. As a result, they have found that a diazosulfonic acid compound capable of generating an acid upon irradiation of radiation and an organic amine compound provide a negative working resist composition which exhibits excellent resolution, forms a resist film with an excellent profile and undergoes no change in characteristics with time (hereinafter referred to as aging stability).
The above object is accomplished by a negative working resist composition essentially comprising (A) a diazosulfonic acid compound capable of generating an acid with irradiation of radiation and (B) an organic amine compound.
DETAILED DESCRIPTION OF THE INVENTION
If desired, the negative working resist composition of the invention can further comprise (C) an organic carboxylic acid compound.
The components (A) and (B) or the components (A) to (C) can be combined with (D) an alkali-soluble resin and (E) a compound capable of causing crosslinking reaction in the presence of an acid (hereinafter referred to as a crosslinking agent) to provide a chemically amplified negative working resist composition capable of forming a resist pattern excellent in resolution and profile.
The diazosulfonic acid compound as component (A) includes those known as an acid generator to be used in negative working resists, such as compounds represented by formula (I):
wherein R
1
represents a branched or cyclic alkyl group having 3 to 8 carbon atoms; and R
2
represents a straight-chain, branched or cyclic alkyl group having 1 to 8 carbon atoms, and the compounds described in JP-A-4-217249. Specific examples of useful diazosulfonic acid compounds are bis(cyclohexylsulfonyl)diazomethane, cyclohexylsulfonylethyl-sulfonyldiazomethane, bis(isopropylsulfonyl)diazomethane, bis(t-butylsulfonyl)diazomethane, bis(sec-butylsulfonyl)-diazomethane, t-butylsulfonylmethylsulfonyldiazomethane, t-butylsulfonylcyclohexylsulfonyldiazomethane, bis(cyclopentylsulfonyl)diazomethane, cyclopentylsulfonyl-t-butylsulfonyldiazomethane, and bis(iso-amylsulfonyl)diazomethane.
The organic amine compound as component (B) includes aliphatic amines, aromatic amines, and heterocyclic amines. Specific examples of the aliphatic amines are monoethanolamine, triethanolamine, methylamine, ethylamine, propylamine, isopropylamine, butylamine, isobutylamine, t-butylamine, pentylamine, isopentylamine, t-pentylamine, hexylamine, heptylamine, octylamine, dimethylamine, diethylamine, dipropylamine, diisopropylamine, trimethylamine, triethylamine, tripropylamine, triisopropylamine, tributylamine, triisobutylamine, tri(t-butyl)amine, tripentylamine, triisopentylamine, tri(t-pentyl)amine, trihexylamine, triheptylamine, and trioctylamine. Specific examples of the aromatic amines are benzylamine, aniline, N-methylaniline, N,N-dimethylaniline, o-methylaniline, m-methylaniline, p-methylaniline, N,N-diethylaniline, and diphenylamine. Specific examples of the heterocyclic amines include pyridine, o-methylpyridine, o-ethylpyridine, 2,3-dimethylpyridine, 4-ethyl-2-methylpyridine, and 3-ethyl-4-methylpyridine. Preferred of them are aliphatic amines. In particular, trimethylamine, triethylamine, tripropylamine, triisopropylamine, tributylamine, triisobutylamine, tri(t-butyl)amine, tripentylamine, triisopentylamine, tri(t-pentyl)amine, trihexylamine, triheptylamine, and trioctylamine are still preferred for forming a resist pattern excellent in resolution and profile.
The diazosulfonic acid compound is used generally in an amount of 0.5 to 30 parts by weight, and the organic amine compound is used in an amount of 0.01 to 5 parts by weight, both per 100 parts by weight of the total composition. Added in smaller amounts, components (A) and (B) bring about insubstantial improvement on profile and aging stability. If added in higher amounts, they hardly dissolve in a solvent completely and have poor miscibility with the resinous component.
The organic carboxylic acid compound which can be used as component (C) is not particularly limited and includes saturated or unsaturated aliphatic carboxylic acids, alicyclic carboxylic acids, hydroxycarboxylic acids, alkoxycarboxylic acids, ketocarboxylic acids, aromatic carboxylic acids, and the like. Incorporation of component (C) brings about further improvement on aging stability.
Examples of suitable organic carboxylic acid compounds include aliphaticmono- or polycarboxylic acids, such as formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid,
Kaneko Fumitake
Kobayashi Masakazu
Miyairi Miwa
Tachikawa Toshikazu
Chu John S.
Fish & Richardson P.C.
Tokyo Ohka Kogyo Co. Ltd.
LandOfFree
Negative working resist composition does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Negative working resist composition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Negative working resist composition will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3105419