Modeling temperature dependent Ni/β-Ga2O3 Schottky barrier diode interface properties

Abstract

A TCAD simulator is used to model measured current–voltage characteristics of Ni/β-Ga2O3 Schottky barrier diode (SBD), deposited by E-beam evaporation, at room temperature. A good fit was obtained when the Ni workfunction, Ni/β-Ga2O3 interface traps concentrations and Si-doped β-Ga2O3 surface electron affinity variation were taken into consideration. Temperature dependent J-V characteristics were investigated and a good agreement at low voltage was obtained. However, the simulated current at high voltage (series resistance domain) was higher than measurement while both series resistance (Rs) and on-resistance (Ron) for measurements were higher than their simulations counterparts. In order to overcome this disagreement, the effect of Si-doped β-Ga2O3 surface electron affinity on the SBD at each temperature was studied. This is due to the fact that the electron affinity can be affected by trap levels located above conduction band maximum (CBM) as reported in the literature. The surface electron affinity decreased with increasing temperature because trap levels located above CBM were activated. A better agreement was achieved.