SiC gate‐controlled bipolar‐field‐effect composite transistor with large on‐state current

Abstract

In this work, a novel bipolar-field-effect composite transistor based on silicon carbide (SiC) Vertical Double-diffused MOSFET (VDMOS) is proposed and investigated for the first time. The novel device is controlled by a gate and is a composite structure of a parasitic Bipolar Junction Transistor (BJT) and a Vertical Double-diffused MOSFET (VDMOSFET), called SiC GCBT (SiC Gate-Controlled Bipolar-field-effect composite Transistor). The structure features using the base-gate short connection mode, instead of the base-source short connection mode, as the traditional SiC VDMOS. So that two conductive channels can be provided by the parasitic bipolar transistor and the metal oxide semiconductor structure for the new device, which not only can improve the integration degreebut also greatly increases the on-state current while the breakdown mechanism remains unchanged. As simulation results show that, compared to the traditional SiC VDMOS with the same parameters, SiC GCBT has the identical BV (about 800 V) and a V th (2.98 V) that is reduced by a factor of 3, and its on-state current is 16.7 times larger than that of SiC VDMOS and is almost unaffected by the width of the Junction Field-Effect Transistor (JFET) region. In addition, under the same gate-controlled voltage, its switching speed can even be compared with that of the traditional SiC VDMOS.