Effect of dual-channel structures on DC characteristics of vertical trench GaN-based MOSFETs

Abstract In this work, five dual-channel vertical trench GaN-based metal oxide semiconductor field-effect transistors (MOSFETs) are proposed and studied. The dual-channel structures include dual two-dimensional electron gas (2DEG) structure, 2DEG and three-dimensional electron gas (3DEG) hybrid structures, and dual 3DEG structure. Compared to the MOSFET with 2DEG from the abrupt GaN/Al 0.3 Ga 0.7 N heterostructure, the MOSFET with 3DEG from the graded Al x Ga 1-x N (0 ≤ x ≤ 0.3) layer can provide more channel electrons, and significantly improve the saturation current and reduce the on-resistance. By introducing three-dimensional hole gas (3DHG) as the current barrier layer (CBL) to optimize the dual-3DEG channel vertical MOSFET, the saturation current of the optimized MOSFET is 2.8 times higher and the on-resistance is reduced by 53% to 1.11 mΩ∙cm 2 at V gs =12 V, and the breakdown voltage is increased from 955 V to 1510 V compared with traditional single-channel MOSFET. Therefore, the optimized dual-channel MOSFET has excellent DC characteristics and can be used as a high-power switching device in next-generation energy and communications applications.