Electron-beam nanolithography and line-edge roughness of acid-breakable resin-based positive resist

Abstract A positive chemical amplification resist based on acid-catalyzed fragmentation of the acetal groups in the polymer main-chain has been developed for electron-beam (EB) nanolithography. This resist consists of an acid generator, an acid-diffusion controller and an acid-breakable (AB) resin that is synthesized through a co-condensation reaction between polyphenol and aromatic multi-functional vinylether compound. Despite a large difference in the molecular weight distribution of the AB resins, the AB resin-based resists (ABRs) provide high-resolution patterns (60-nm line-and-spaces) with high sensitivity ( 2 at 30 kV). AFM analysis showed the surface roughness for ABR is less than half (RMS: ∼1 nm) compared with that for novolak resin-based resist. By using ABR, the sub-100 nm L/S patterns with line-edge roughness (3 σ ) about 5 nm are obtained.