Study of high breakdown voltage GaN-based current-aperture vertical electron transistor with source-connected field-plates for power applications

A GaN-based current-aperture vertical electron transistor with source-connected field-plates (SFP-CAVET) is proposed and investigated by means of two-dimensional simulations. This device is characterized by the source-connected field-plates (SFP) at both sides, which leads to remarkable improvement of breakdown voltage (BV) without degradation of specific on-resistance (R _on). Systematic analyses are conducted to reveal the mechanism of the SFP modulation effect on the potential and the electric field distributions and thus the BV improvement. Optimization and design of SFP-CAVET are performed for the maximum BV. Simulation results exhibit a R _on of 2.25 mΩ • cm² and a significantly enhanced BV of 3610 V in SFP-CAVET, indicating an average breakdown electric field of more than 240 V μm^-1. Compared with conventional CAVET, both BV and average breakdown electric field in SFP-CAVET are increased by more than 121% while R _on remains unchanged. And the trade-off performance of BV and R _on in SFP-CAVET is also better than that in GaN-based CAVET with superjunctions (SJ CAVET). In addition, the fabrication process issues of the proposed SFP-CAVET are also presented and discussed. These results could break a new path to further improve the trade-off performance of BV and R _on in GaN-based vertical devices.