DEVELOPMENT OF INXGA1-XAS-BASED OHMIC CONTACTS FOR P-TYPE GAAS BY RADIOFREQUENCY SPUTTERING

InxGa1-xAs-based ohmic contacts which showed excellent contact propert ies for n-GaAs were demonstrated to be applicable to p-GaAs ohmic cont acts. These contacts, prepared by radio-frequency sputtering, provided low contact resistance (0.2 Omega-mm), excellent thermal stability, s mooth surface, and good reproducibility. The contact resistances had a weak dependence on the annealing temperatures, which was desirable in a manufacturing view point. This weak. temperature dependence was exp lained to be due to a unique Schottky barrier height at the metal/p-In xGa1-xAs interface which does not depend on the In concentration in th e InxGa1-xAs layer. The present experiment showed the possibility of s imultaneous preparation of ohmic contacts for both n and p-GaAs using the same contact materials.