Acid-labile group protected hydroxystyrene polymers or copolymers thereof and their application to radiation sensitive materials

An acid-labile group protected hydroxystyrene polymer or copolymer thereof represented in formula I:

• ##STR3## Wherein m and o are independently an integer of 1 or more provided that o/m+o=0.1 to 0.9;
• and n is zero or an integer of 1 or more, provided that when n is an integer of 1 or more, n/m+n+o=0.05 to 0.5,
• R.sub.1, R.sub.2, R.sub.5, and R.sub.6 represent independently hydrogen atom or an alkyl group with 1 to 6 carbon atoms,
• R.sub.3 and R.sub.4 represent independently hydrogen atom, a cyano group, an alkyl group with 1 to 6 carbon atoms, an aryl group with 6 to 10 carbon atoms, a substituted aryl group or a --COOR.sub.10 group, or R.sub.3 and R.sub.4 together form a cyclic group represented by --C(O)OC(O)-- or --C(O)NR.sub.10 C(O)--, with
• R.sub.10 being hydrogen atom, a linear, branched or cyclic alkyl group with 1 to 6 carbon atoms, an aryl group with 6 to 10 carbon atoms, or an alkaryl group with 7 to 10 carbon atoms,
• R.sub.7 and R.sub.8 represent independently hydrogen atom, chlorine atom, bromine atom, an alkyl group with 1 to 6 carbon atoms or a substituted alkyl group with 1 to 6 carbon atoms, p and q are an integer of 1 to 4 independently,
• R.sub.9 is represented by the formula II
• --CH(CH.sub.3)OR.sub.11 OXR.sub.12 (II)
• wherein
• R.sub.11 represents a linear or branched alkylene group with 2 to 6 carbon atoms,
• X represents a direct bond, or a --C(O)--, --C(O)O--, --S(O.sub.2)--, --C(O)NH-- or --C(S)NH-- group, and
• R.sub.12 represents a linear, branched or cyclic alkyl group with 1 to 6 carbon atoms, a substituted alkyl group with 1 to 6 carbon atoms, an aryl group with 6 to 10 carbon atoms, a substituted aryl group with 6 to 10 carbon atoms, or an alkalyl group with 7 to 10 carbon atoms.