Copolymer, positive resist composition, and method of forming resist pattern
AssigneeZeon Corporation
InventorManabu Hoshino
Life of this patent
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Abstract
A copolymer includes a monomer unit (A) represented by formula (I), shown below, and a monomer unit (B) represented by formula (II), shown below, and has a weight-average molecular weight of 230,000 or more. In the formulae, L is a single bond or a divalent linking group, Ar is an optionally substituted aromatic ring group, R1 is an alkyl group, R2 is hydrogen, an alkyl group, a halogen atom, a haloalkyl group, a hydroxy group, a carboxy group, or a halocarboxy group, p is an integer of not less than 0 and not more than 5, and in a case in which more than one R2 is present, each R2 may be the same or different.
Claims10
A copolymer comprising:
- a monomer unit (A) represented by formula (I), shown below,
- where, in formula (I), L is a single bond or a divalent linking group and Ar is an optionally substituted aromatic ring group;
- and
- a monomer unit (B) represented by formula (II), shown below,
- where, in formula (II), R1 is an alkyl group, R2 is hydrogen, an alkyl group, a halogen atom, a haloalkyl group, a hydroxy group, a carboxy group, or a halocarboxy group, p is an integer of not less than 0 and not more than 5, and in a case in which more than one R2 is present, each R2 may be the same or different, wherein
- the copolymer has a weight-average molecular weight of 230,000 or more, and
- a difference between weight-average molecular weight Mw20 thereof upon exposure with an electron beam irradiation dose of 20 μC/cm2 and weight-average molecular weight Mw40 thereof upon exposure with an electron beam irradiation dose of 40 μC/cm2 is 12,100 or more.
Dependencies are inferred from the claim text.