Simulation study of a novel GaN on Si Quasi‐Vertical Reverse‐Conducting Insulated Gate Bipolar Transistor

Abstract In this paper, a novel GaN on Si quasi-vertical reverse conducting insulated gate bipolar transistor(RC-IGBT) with a new NPN structure is proposed and simulated by Silvaco TCAD. The distinctive feature of this structure lies in fabricating the original bottom P-Collector on the wafer surface. In comparison to conventional IGBT devices with PNPN structures, this NPN structure overcomes two major challenges: the difficulty in forming ohmic contacts due to the activation difficulty of the bottom P-GaN and the necessity of creating backside through-holes for electrode formation. Simultaneously, the N-GaN in the emitter and reverse-conducting regions can be selectively regrown through Metal-Organic Chemical Vapor Deposition (MOCVD) or Molecular Beam Epitaxy (MBE), avoiding the etching effect of top-layer N-GaN on P-GaN during the fabrication of P-type electrodes. This approach demonstrates a high level of process feasibility. In this paper, Silvaco TCAD is used to simulate the static and dynamic characteristics of this novel quasi-vertical RC-IGBT device. The simulation results reveal that the device has a high saturation current(Ion,sat) density of 18224.67A/cm2 at Vge=14V,a threshold voltage (Vth) of 5V,a breakdown voltage of 828V,a latch-up voltage of 800V ,and a switching speed of nanoseconds. In addition, the selection of device parameters is studied in this paper.