A novel noria (water-wheel-like cyclic oligomer) derivative as a chemically amplified electron-beam resist material

Abstract

A novel ladder-type cyclic oligomer (molecular water-wheel = noria) derivative containing t-butyl ester groups was synthesized. This derivative (noria-COOtBu) had good thermal stability, good solubility in common organic solvents, and good film-forming ability. The photo-induced deprotection (UV irradiation for 30 min followed by heating at 130 °C) of films of noria-COOtBu was examined in the presence of a photo-acid generator, and it was found that deprotection of the t-butyl groups proceeded smoothly to give the corresponding carboxylic acid derivative (noria-COOH). Furthermore, when noria-COOtBu(71) (ratio of t-butyl ester groups: 71%) was examined as an electron-beam resist material, a clear line and space pattern was obtained at a resolution of 70 nm.