Fine pattern formation of gallium arsenide by in situ electron-beam lithography using an ultrathin surface oxide as a resist
Formation of fine patterns such as lines and spots on a GaAs surface by in situ electron beam (EB) lithography is demonstrated. An ultrathin surface oxide (less than 1 nm) of GaAs is used as a resist film, which can be patterned by EB-assisted etching. The minimum pattern size of less than 1.0 micron is obtained; it is limited by the electron beam shape in the present experiment. The EB-induced patterning of the oxide resist is not due to substrate heating or minority carrier generation, but to excitation of the sample surface and/or the chlorine atoms adsorbed on the oxide resist film.