10‐nm linewidth electron beam lithography on GaAs

Metal features with 10‐nm linewidths were produced on thick GaAs substrates using electron beam lithography. A single layer of polymethylmethacrylate (PMMA) was exposed by an approximately 2‐nm‐diam electron beam with energies ranging from 20 to 120 keV. Gold‐palladium lines less than 20 nm wide, and 15 nm thick, with center‐to‐center spacings of 70 nm, were produced over 15‐μm square fields at all electron beam energies by lift off. The exposure latitude increased significantly for higher electron energies, with 10‐nm‐wide metal lines formed using a 120‐keV writing beam.