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US 6,033,826 AGranted
Polymer and resist material
AssigneeWako Pure Chemical Industries, Ltd.
InventorsFumiyoshi Urano, Hirotoshi Fujie, Keiji Oono
Life of this patent
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Abstract
A polymer of polyhydroxystyrene derivative containing an acetal or ketal group which can easily be eliminated in the presence of an acid in the molecule and having a very narrow molecular weight distribution gives a resist material suitable for forming ultrafine patterns excellent in resolution, heat resistance, mask linearity, and other properties without causing problems of delay time and the like.
Claims11
A polymer having repeating units of the formula:
- ##STR29## wherein R.sup.1 and R.sup.2 are independently a hydrogen atom or a lower alkyl group;
- R.sup.3 and R.sup.4, which cannot be both hydrogen atoms, are independently a hydrogen atom or an alkyl group which may be substituted with one or more halogen atom, or R.sup.3 and R.sup.4 can form an alkylene ring together with the interposing carbon atom;
- R.sup.5 is an alkyl group which may be substituted with one or more halogen atom, or an aralkyl group;
- R.sup.6 is a phenyl group which may have one or more substituent, a carboxyl group which may be substituted with an alkyl group, or a cyano group;
- m and n are independently an integer of 1 or more;
- k is zero or an integer of 1 or more, provided that 0.1.ltoreq.(m+k)/(m+n+k).ltoreq.0.9 and 0.ltoreq.k/(m+n+k).ltoreq.0.25, said polymer having a degree of molecular weight dispersion of 1 or more, and less than 1.5.
3 more elements
Dependencies are inferred from the claim text.