Monocrystalline aluminium ohmic contact to <i>n</i>-GaAs by H2S adsorption

Abstract

700-K H2S adsorption in the monolayer range onto the GaAs (100) surface induces profound modifications of surface properties. Al in situ epitaxially deposited near room temperature by molecular beam epitaxy (MBE) on a H2S adsorbed semiconductor surface exhibits low-effective Schottky-barrier height. It is shown that this Schottky-barrier lowering can be used to obtain monocrystalline nonalloyed ohmic contacts with low specific-contact resistances.