Blended novolac resins with improved lithographic performance

摘要

Statistically designed experiments were performed to optimize novolac blending techniques which would yield superior photoresists. The best lithographic performance was obtained when two novolacs to be blended had dissimilar relative molecular weights (RMW) while also having matched dissolution rates (DR), (lithographic performance $EQ (RMW$-A$/ $MIN RMW$-B$/)/(DR$-A$/ $MIN DR$-B$/). A calculated plot of (RMW$-A$/ $MIN RMW$-B$/)/(DR$-A$/ $MIN DR$-B$/) matched the experimental plot of lithographic performance well.