Simulation study for GaN-based hybrid trench MOS barrier Schottky diode with an embedded p-type NiO termination: increased forward current density and enhanced breakdown voltage

Abstract

In this work, a hybrid trench MOS barrier Schottky diode (TMBS) structure is proposed to improve both the forward current density and the breakdown voltage by using TCAD simulation tools. The hybrid structure means that the conventional TMBS rectifier is combined with a p-NiO/n-GaN diode. According to our study, when the device is in the forward-biased condition, the embedded p-type NiO layer forms a PN junction. This can modulate the lateral energy bands by removing the conduction band barriers for electrons. Thus, the improved current spreading effect and the better conductivity modulation can be obtained, leading to the increased current density. Meanwhile, the embedded p-type NiO layer can also help to reduce the electric field at the Schottky contact interface and the edge of anode contact/p-NiO layer interface. Thus, the breakdown voltage can be improved remarkably. Moreover, a detailed optimization strategy for the hybrid TMBS is also analyzed by varying the p-NiO layer thickness (T NiO) and the lengths of the anode electrode that is covered on the p-NiO layer (L A).