Low-resistance nonalloyed ohmic contacts on p-type GaAs using GaSb/GaAs strained-layer superlattices

Employing a GaSb/GaAs strained-layer superlattice and a GaSb cap, specific contact resistivities as low as 3.2×10−7 Ω cm2 have been realized for nonalloyed ohmic contact to p-type GaAs. This contact structure is shown to give low contact resistances irrespective of the contact metals, including AuBe, AuGe/Ni/Au, and Au. Excellent thermal stability for AuBe contacts was obtained when sintered.