Effect of microwave treatment on the properties of Au-TiBx-Al-Ti-n-GaN ohmic contacts

Abstract

We studied the effect of microwave irradiation (frequency of 2.45 GHz, irradiance of ~1.5 W/cm2) for 2-100 s on the characteristics of Au-TiBx-Al-Ti-n-GaN contact structures. A correlation between the contact resistivity changes and wafer curvature was found. This indicates considerable effect of intrinsic stresses on contact resistivity. Relative spread of ohmic contact resistance values decreases with irradiation time. This may indicate local intrinsic stresses homogenization enhanced by microwave irradiation.