Simulation studies of Single Event Effects in Ga${}_2$O${}_3$ MOSFETs

Abstract

In this article, we investigate the Single Events Effects (SEE) leading to Single Event Burnout (SEB) in $\beta$-Ga${}_2$O${}_3$ MOSFETs. Using Silvaco TCAD, 2D simulations were performed to understand the mechanism behind the SEB mechanism in lateral Ga${}_2$O${}_3$ MOSFETS. The high electric fields in the channel played a critical role leading to high impact generation rates and eventual SEB. To reduce the electric field in the channel, radiation hardened designs are then proposed with rounded gates and the use of a combination of high permittivity (k) dielectric with SiO${}_2$. With HfO${}_2$-SiO${}_2$ dielectric combination, the SEB threshold of 550V at LET=10 MeV/mg/cm${}^2$ is seen. However, to operate under extreme radiation conditions, a combination of very high-k dielectric material BaTiO${}_3$ with SiO${}_2$ is proposed. Using the radiation hardened design, SEB thresholds up to 1000 V for LET=75 MeV/mg/cm${}^2$ could be achieved which is higher than the state-of-the-art technology. The energy dissipated during the ion strike event is also calculated and it is observed that it is lower than that of SiC MOSFETs.