DISSOLUTION KINETICS ANALYSIS FOR CHEMICALLY AMPLIFIED DEEP-ULTRAVIOLET RESIST

Dissolution kinetics of a chemically amplified deep-ultraviolet (DUV) positive resist, which consists of tert-butoxycarbonyl (t-BOC)-protected phenolic resin, benzenesulfonic acid derivative as a photoacid generator (PAG) and an additional dissolution inhibitor, has been investigated by focusing on the t-BOC-protected phenolic resin structure (t-BOC protection ratio/molecular weight M(W)) and postexposure bake (PEB) temperature. Based on the analysis of the dissolution rate curve and Arrhenius plots, it was concluded that only one mechanism, namely, the penetration of tetramethylammonium hydroxide (TMAH) developer into hydrophobic t-BOC resin, rules the dissolution kinetics. It was also found that a steep slope of the dissolution rate curve is very effective for improving resolution capability. Polymer structure, as well as the PEB condition, was optimized from the correlation between dissolution kinetics and resist performance, and good resist performance was realized.