Patent ID: 7601482

Claim:
A negative photoresist composition comprising; a) at least one alkali-soluble polymer, where the polymer comprises at least one unit of structure 1, where, R′ is selected independently from hydrogen, (C 1 -C 4 )alkyl, chlorine and bromine, and m is an integer from 1 to 4; b) at least one monomer of structure 4; where, W is a multivalent linking group, R 1 to R 6 are independently selected from hydrogen, hydroxy, (C 1 -C 20 ) alkyl and chlorine, X 1 and X 2 are independently oxygen and n is an integer equal to or greater than 1; and, c) at least one photoinitiator, and, further where the monomer of structure 4 comprises an acid-cleavable group and the alkali-soluble polymer further comprises an acid-cleavable group.