Resist Characteristics of Acryl Polymer with Methyl Acetal Protecting Group for 193 nm Lithography

Abstract

We have prepared three different methyl acetal acryl polymers (2-admantyloxy methyl: AdOM, 1-methyladamantyloxy methyl: MAdOM and 4-oxo-2-admantyloxy methyl: OAdOM) to evaluate polymer properties compared with 2-methyl-2-admantyl (MAd). It was found from the thermal analysis, that the Tg of methyl acetal polymers are lower than that of MAd and Td of methyl acetal polymers are higher than that of MAd. We have found that the acid catalyzed deprotection reactivity of methyl acetal polymers (AdOM and MAdOM) resists are higher than that of MAd resist and the dissolution of methyl acetal polymers film were accelerated with 30 % more deprotection using FT-IR study. In addition, the AdOM resist displayed a good PEB sensitivity of 120 nm 1:1 dense line pattern with values of 3.43 nm/ °C, when the MAd resist displayed 4.29 nm/ °C.