Modeling of the gate leakage in MOSFETs with Al2O3/β-Ga2O3 gate stack

An accurate modeling of the current conduction through the gate stack is needed to identify the residual conduction paths, to improve the behavior of the device in future iterations of the technological process. Models available in the literature are applied to the study of experimental gate leakage measurements in gallium oxide MOSFETs in a wide temperature range, from cryogenic temperature up to 350 K. Experimental results show a dominant Poole-Frenkel mechanism at high temperature and high bias, and Fowler-Nordheim tunneling at low temperature. A suitable rate equation was developed to model the time-dependent behavior of the gate leakage with applied bias. The gate leakage model was implemented in TCAD, and is able to reproduce the experimental behavior from the milliseconds to the hundreds of seconds range.