Effects of Protecting Group of Fluoroalcohol on Lithographic Performance

We have investigated effects of protecting group of fluoroalcohol as alkaline solubility on lithographic performance for the designing of chemical amplification positive-tone resist system. Preparing three different protecting groups (methoxymethyl: MOM, ethoxymethyl: EOM and fluoroethoxymethyl: FEOM) of norbornene hexafluoro-isopropanol (NBHFA) polymers and resists consisted of these polymers, we have evaluated optical properties, dissolution rates with developer, exposure sensitivities and resolution. These polymers showed a good pattern profile and high resolution. In addition, as compared with NBHFA-MOM and -EOM polymers, NBHFA-FEOM polymer displayed a good absorption coefficient at 157 nm.