THE DECREASE OF DISSOLUTION RATE IN UNEXP OSED AREAS OF CHEMICALLY AMPLIFIED 3-COMPONENT POSITIVE RESIST BY MEANS OF TERT-BUTYL CARBONATE AS A DISSOLUTION INHIBITOR

The dissolution characteristics of a chemically amplified electron bea m (EB) resist composed of partially tert-butoxycarbonyl group (tBOC) p rotected poly(p-vinylphenol) (PVP), a dissolution inhibitor, and an ac id generator were investigated. We tried to decrease the dissolution r ate of the resist in the unexposed areas using dissolution inhibitors. We estimated the dissolution rate by using a model-composition resist which consists of tBOC-PVP as matrix resin and three differently orie nted dihydroxybenzenes protected with tBOC as dissolution inhibitors. We evaluated the relationship between the melting point of dihydroxybe nzens protected with tBOC and the dissolution rate of model-compositio n resist. The higher the melting point of dihydroxybenzen protected wi th tBOC, the lower the dissolution rate of model-composition resist. T he higher the melting point of dihydroxybenzen protected with tBOC, th e less the decomposition of the tBOC group of the dissolution inhibito rs at prebake. We think that the polymer hardness becames softer by ad ding a dissolution inhibitor with a low melting point. The dissolution inhibitor with a low melting point acted as a flexibilizer in the mod el-composition resist. It was found that a dissolution inhibitor with a high melting point decreases the dissolution rate of a resist in the unexposed areas.