Nonlinear analysis of vanadium- and titanium-based contacts to Al-rich n-AlGaN

Abstract

In this work, we report on voltage dependent contact characteristics of Al-rich n-AlGaN due to the presence of a Schottky barrier at the metal- AlGaN interface. Current-voltage characteristics appear to be linear at low voltages, but a clear nonlinearity is evident at high voltages. Unlike Garich n-AlGaN where V-based contact marginally outperforms the Ti-based contact, V-based contact to Al-rich n-AlGaN outperforms the Ti-based contact by 2 orders of magnitude for all voltage ranges. The improved performance of V-based contacts is likely due to a lower Schottky barrier and partly due to ease of formation of a low barrier V-AlGaN interface. © 2017 The Japan Society of Applied Physics.