Method for preparing lithographically sensitive branched novolaks using a mannich base intermediate

摘要

A method for preparing branched novolak polymers possessing excellent lithographic performance is provided. The method involves the acid catalyzed reaction of a tris- or tetrakis(dialkylaminoalkyl) phenol or bisphenol with one or more phenol having at least one unsubstituted ortho- or para- ring position. The branched novolaks are soluble in aqueous base and organic solvent solutions and are particularly useful as the polyeric component of either positive-acting or negative-acting photoresist compositions.