2001 Volume 14 Issue 4 Pages 595-601
Fluoropolymers are promising materials for the single-layer resists used in 157-nm lithography. The fluoropolymer positive-tone resists we studied showed high optical transparencies at 157nm (absorption coefficients of 0.01 to 2μm-1), their dry-etching resistance was comparable to that of an ArF resist. They showed good sensitivities, from 1 to 10mJ/cm2, and high contrast in their sensitivity curves. The quartz-crystal-microbalance method showed that these resists swelled transiently during development and that the rate at which they dissolves was slower near the interface between the resist and the substrate than it was in the bulk of the resist.
