Development of high contrast EUV photoresist for narrow pitch C/H patterning

The organic non-chemically amplified resist (non-CAR) materials have been developed for fine pitch contact hole patterning process to remove the acid blur of conventional chemically amplified resist (CAR) system, but non-CAR materials usually show lower contrast and sensitivity compared to conventional CAR materials, so additional improvements are needed for practical application. In this study, we developed new platforms of EUV PTD resist materials to overcome these limitations and enable fine pitch C/H patterning. The main target of our study is to reduce acid blur and to maintain chemical contrast compared to conventional CAR system by 1) finding better EUV-active structures, or 2) simultaneously generating polarity switching and molecular weight (M.W.) change, or 3) maximizing the M.W. change through the depolymerization. Those new resist materials have confirmed showing equivalent or higher contrast compared to conventional CAR, and also having good resolution in EUV C/H patterning evaluation.