Sensitivity enhancement of chemically amplified EUV resists by adding acid-generating promoters

The trade-off relationship between sensitivity, resolution, and roughness is a serious problem in the development of extreme ultraviolet (EUV) resist materials. Increasing the acid-generation efficiency is an effective solution to this trade-off problem. Chemically amplified resists (CARs) remain important for EUV lithography because of their longstanding use in photolithography. In this study, the feasibility and mechanism of improving CAR performance by adding acid-generating promoters were investigated. It was confirmed that di-p-tolyl sulfone acts as both a deprotonation promoter and a recombination inhibitor, which enhances the acid-generation efficiency and improves the performance of CARs in lithographies using ionizing radiation such as EUV and electron beams.