Low-Resistivity Non-Alloyed Ohmic Contacts to p- and n-Gaas Using In-Situ Integrated Process

Abstract

ABSTRACTVery low-resistivity non-alloyed ohmic contacts (Rc) to both p- and n-GaAs were realized using molecular beam epitaxy (MBE) in a vacuum integrated system. Three different metals of Au, Ag, and Nb were in-situ deposited on (1) p+-GaAs which was heavily Be-doped either in a uniform doping or with a 5-doping scheme; and (2) n+-GaAs which was doped in a 5-pair Si δ-doping with a spacer GaAs-Si 2.5 nm thick. In both cases, low Rc values of ≤ (1-5) x 10-7 Ω-cm2 were achieved.