Thermal stability of Pd-In OHMIC contacts to n-GaAs formed by scanned electron beam and rapid thermal annealing

Abstract

Thermally stable and low resistance Pd-In ohmic contacts to n-GaAs were formed using scanned electron beam (SEB) and rapid thermal annealing (RTA). A specific contact resistance (ρ c ) of the order of ∼10 −6 Ωcm 2 was obtained using both SEB and RTA techniques with SEB annealed contacts exhibiting a superior surface morphology. High temperature aging (500°C) of the contacts showed that SEB annealed contacts were more stable than RTA contacts as shown by the increase in their respective ρ c values (an increase by a factor of ∼5 for SEB annealed contacts against an increase by a factor of ∼8 for RTA contacts after 25 hours of aging)