Shin-Etsu Chemical Co., Ltd.

Junji Shimada

Satoshi Watanabe

Toshinobu Ishihara

Youichi Ohsawa

Katsuya Takemura

Kazumasa Maruyama

Shigehiro Nagura

Fujio Yagihashi

Yoshihumi Takeda

Osamu Watanabe

Yoichi Osawa

A polymer comprising recurring units of formula (1) is provided wherein some of the hydrogen atoms of phenolic hydroxyl groups and/or alcoholic hydroxyl groups are replaced by acid labile groups. The polymer is crosslinked within a molecule and/or between molecules with a crosslinking group having a C--O--C linkage resulting from reaction of some of the remaining phenolic hydroxyl groups and/or alcoholic hydroxyl groups with an alkenyl ether compound or halogenated alkyl ether compound. The amount of the acid labile group and the crosslinking group combined is on the average from more than 0 mol % to 80 mol % of the entirety of the phenolic hydroxyl group and alcoholic hydroxyl group. The polymer has Mw of 1,000-500,000. ##STR1## R.sup.1 is H or methyl, R.sup.2 is C.sub.1 -C.sub.8 alkyl, letter x is 0 or a positive integer, y is a positive integer, x+y.ltoreq.5, letters p and q are positive numbers satisfying p+q=1 and 0&lt;q/(p+1).ltoreq.0.9. A chemically amplified positive resist composition comprising the polymer as a base resin has high sensitivity and resolution and forms resist patterns having plasma etching resistance, heat resistance, overhang prevention, and dimensional controllability.

Partially hydrogenated polymers and chemically amplified positive resist

The invention provides a novel sulfonium salt having a substituted or unsubstituted arylsulfonate anion. The novel sulfonium salt minimizes the influence of deactivation by basic compounds not only at a resist surface, but also at a resist-substrate interface, assists a resist to be configured to a definite pattern profile. When the sulfonium salt has an acid labile group, it is effective for increasing the dissolution contrast between exposed and unexposed areas. The sulfonium salt is useful in a chemically amplified positive resist composition which lends itself to fine patterning and features high resolution.

Sulfonium salts and chemically amplified positive resist compositions

By reacting an aryl Grignard reagent of the following general formula (1) with thionyl chloride and then reacting the reaction product with a triorganosilyl sulfonate or triorganohalide of the general formula (2): (R.sup.6).sub.3 SiY wherein R.sup.6, which may be the same or different, is a monovalent hydrocarbon group and Y is a substituted or unsubstituted alkylsulfonate or arylsulfonate or halogen atom, there is prepared a triarylsulfonium salt of the following general formula (3). ##STR1## In the formulae, each of R.sup.1 to R.sup.5, which may be the same or different, is a hydrogen atom or a monovalent organic group, especially alkyl, aryl, alkoxy, aryloxy, dialkylamino, dialkylaminoalkyl, alkylthio or arylthio group and X is a bromine or chlorine atom.

Method for preparing triarylsulfonium salts

Trifluoromethanesulfonic and p-toluenesulfonic acid bis- or tris(p-tert-butoxyphenyl)sulfonium salts are novel. They are prepared from bis(p-tert-butoxyphenyl)sulfoxide which is also novel. A chemically amplified positive resist composition which contains the sulfonium salt as a photo-acid generator is highly sensitive to deep-UV rays, electron beams and X-rays, can be developed with alkaline aqueous solution to form a pattern, and is thus suitable for use in a fine patterning technique.

Sulfonium salt and chemically amplified positive resist composition

Tristertbutoxyphenyl sulfonium tosylate compound

A novel sulfonium salt having at least one substituted aromatic group having acid labile groups and at least one nitrogenous aromatic group is provided. A chemically amplified, positive resist composition comprising the sulfonium salt as well as an alkali soluble resin and a dissolution inhibitor in an organic solvent has solved the PED problem.

Growing community of inventors

Nakakubiki-gun, Japan

Junji Shimada