3D-simulation design of a high current capacity GaN Tri-gate power device with integrated parasitic bipolar junction

Abstract In this work, a novel high current capability Gallium Nitride (GaN) Tri-gate power device with an integrated parasitic bipolar junction transistor (BJT) is proposed to enhance its static electrical characteristics. The device's electrical characteristics are thoroughly studied and analyzed using 3D Technology Computer-Aided Design (TCAD) simulation tools. The two-dimensional electron gas (2DEG) channel is effectively pinched off in the off-state due to the depletion region induced by side-gate metals and parasitic BJT, resulting in a positive threshold voltage (VTH) and enhanced mode (E-mode) operation. The parasitic BJT provides an additional conductive channel in the on-state, significantly improving the output current capability. Compared with the conventional Tri-gate (C-Trigate) device, the proposed high current capability GaN Trigate (HC-Trigate) device boosts saturation output current by nearly a factor of three under identical conditions, reaching 1,761 mA/mm. The 3D simulation shows the proposed GaN HC-Trigate power device features a positive VTH of 1.1 V, a low specific on-resistance (Ron,sp) of 0.18 mΩ*cm2 at breakdown voltage (BV) of 760 V, and the
Baliga’s figure of merit (BFOM) of 3.21 GW/cm2. Furthermore, the GaN HC-Trigate power device exhibits superior thermal performance and switching characteristics, indicating its great potential for power electronics applications.