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

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 ( rho _c) of the order of approximately 10^-6 Omega cm² was obtained using both SEB and RTA techniques with SEB annealed contacts exhibiting a superior surface morphology. High temperature aging (500 degrees C) of the contacts showed that SEB annealed contacts were more stable than RTA contacts as shown by the increase in their respective rho _c values (an increase by a factor of approximately 5 for SEB annealed contacts against an increase by a factor of approximately 8 for RTA contacts after 25 hour s of aging).