Thermally stable in-based ohmic contacts to p-type GaAs

Abstract

Thermally stable, low resistance p-type ohmic contacts have been developed by depositing NiInW alloys on GaAs substrates in which Be and F were co-implanted. The contacts provided resistances of about 0.6 Ω-mm after annealing at temperatures in the range of 300 to 800°C for short times. The electrical properties did not deteriorate after annealing at 400°C for more than 100 hrs, which far exceeds the requirements for current GaAs device fabrication. The present study demonstrates, for the first time, that thermally stable, low resistance ohmic contacts to both n- and p-type GaAs can be fabricated using the same metallurgy.