Shin-Etsu Chemical Co., Ltd.

Kiyoshi Motomi

Toshinobu Ishihara

Shigehiro Nagura

Jun Hatakeyama

Ichiro Kaneko

Takeshi Nagata

Masahiro Yuyama

Atushi Sugitani

Satoshi Watanabe

Osamu Watanabe

A polymer comprising recurring units of formula (1) is provided wherein some hydrogen atoms of phenolic hydroxyl groups and/or carboxyl groups are replaced by acid labile groups. The polymer is crosslinked with a crosslinking group having a C--O--C linkage resulting from reaction of some of the remaining phenolic hydroxyl groups and/or carboxyl 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 carboxyl group. The polymer has Mw of 1,000-500,000. R.sup.1 is H or methyl, R.sup.2 is C.sub.1 -C.sub.8 alkyl, R.sup.3 is H, R.sup.4 is --COOR.sup.5, C.sub.1 -C.sub.5 alkyl or phenyl, or R.sup.3 and R.sup.4, taken together, may form --COOCO--, R.sup.5 is H or C.sub.1 -C.sub.8 alkyl, x and y are integers satisfying x+y.ltoreq.5, p and q are positive numbers satisfying p+q=1 and 0&lt;q/(p+q).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.

Polymers and chemically amplified positive resist compositions

In a chemically amplified positive resist composition comprising an organic solvent, an acid labile group-protected resin and a photoacid generator, a compound having a weight average molecular weight of 100-1,000 and at least two phenolic hydroxyl groups in a molecule wherein the hydrogen atom of the phenolic hydroxyl group is partially replaced by an acid labile group in an overall average proportion of 10-80% is blended as a dissolution controller. The resist composition is highly sensitive to actinic radiation, has improved sensitivity and resolution, and is suitable for use in a fine patterning technique and commercially acceptable.

Chemically amplified positive resist composition

In a chemical amplification positive resist composition comprising an organic solvent, a resin and a photoacid generator, at least two polymers having different molecular weights selected from polyhydroxystyrenes having some hydroxyl groups protected with acid labile groups are used. Among the polymers, a high molecular weight polymer has a molecular weight dispersity (Mw1/Mn1) of up to 1.5, and a low molecular weight polymer has a dispersity (Mw2/Mn2) of up to 5.0. The weight average molecular weight ratio Mw1/Mw2 is between 1.5/1 and 10.0/1. The resist composition is highly sensitive to actinic radiation, has improved sensitivity and resolution, and is suitable for use in a fine patterning technique and commercially acceptable.

Polyimides comprising recurring units of the following general formula (1) ##STR1## wherein Ar.sub.1 represents a tetravalent aromatic group and each Ar.sub.2 represents a divalent aromatic group. Polyimide copolymers and preparations of the polyimides and the polyimide copolymers are also described.

Polyimides and processes for preparing the same

Polyimides comprising recurring units of the following general formula (1) ##STR1## wherein R.sub.1 represents a tetravalent aromatic group. Polyimide copolymers and preparations of the polyimides and the polyimide copolymers are also described.

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Nakakubiki-gun, Japan

Kiyoshi Motomi