Thermally stable phenolic resin compositions with ortho, ortho methylene linkage

摘要

A phenolic resin composition comprising units of formula (I): <IMAGE> (I) wherein R1 is a halogen and R2 is a lower alkyl group having 1 to 4 carbon atoms, and said units of formula (I) are made by condensing the corresponding halogen-substituted resorcinol of formula (A): <IMAGE> (A) wherein R1 is defined above, with the corresponding para-lower alkyl-substituted 2,6-bis(hydroxymethyl)-phenol of formula (B): <IMAGE> (B) wherein R2 is defined above, and wherein the mole ratio of A:B is from about 0.5:1 to 1.7:1. This phenolic resin may be mixed with photoactive compounds (e.g. 1,2-naphthoquinone diazide sensitizers) to prepare a light-sensitive composition useful as a positive-working photoresist.