Low resistance Pd/Ge/Au and Ge/Pd/Au ohmic contacts to n-type GaAs

Abstract
We have fabricated Pd/Ge/Au and Ge/Pd/Au sintered ohmic contacts on n‐type GaAs. These contacts have specific resistances similar to those of conventional Ni/Ge/Au alloyed ohmic contacts, but their surfaces are much smoother and their edges are well defined. The fabrication procedure is compatible with GaAs technology, and the sintered contacts are thermally stable. The properties of these low resistance contacts are insensitive to the sintering temperature and to the thickness of the Pd and Ge layers or their order of deposition.