A non-Ohmic normally-off GaN monolithic bidirectional switch with MIS field effect schottky tunnel junction

Abstract

A non-Ohmic normally-off GaN Monolithic bidirectional switch (MBS) with two metal-insulator-semiconductor field-effect schottky tunnel junctions is proposed and investigated by TCAD sentaurus. The MBS exhibits normally-off operation on account of the thick tunnel barrier at schottky-source and schottky-drain electrodes, whose effective thickness is controlled by two insulated gates next to source and drain. A positive gate bias can pull down the conduction band and result in a thin tunnel barrier with high tunneling current, while a zero gate bias brings about a thick barrier effectively suppressing the tunneling current. The simulated results show that the proposed MBS can deliver a low off-state current of 10 μA and a small on-state voltage of 3.55 V at the same time. And compared with the conventional Ohmic-contact MBS, the proposed MBS does not show any degeneration in on-state loss. Moreover, the absence of Au-based Ohmic process and high temperature annealing process enables the proposed MBS with CMOS compatibility and low thermal budget.