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 (p(c) of the order of approximately 10(-6) OMEGA-cm2 ws 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 p(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 hours of aging).