Epoxide functionalized molecular resists for high resolution electron-beam lithography

Abstract

Chemically amplified resists would be a preferred option to non-amplified resists such as PMMA or ZEP for electron-beam lithography because of their much higher sensitivity and therefore faster write times, but are resolution limited compared to non-amplified resists due to photoacid diffusion. A chemically amplified molecular resist based on epoxide polymerization (4-Ep) has been developed that simultaneously has resolution of 35nm half-pitch, sensitivity of 20μC/cm2, and line edge roughness (3σ) of 2.3nm. The resist combines the performance advantages of both a molecular and polymeric resist. The extensive cross-linking effectively limits photoacid diffusion during resist processing, thus allowing for high resolution.