Vertical GaN-on-Si MOSFET/JBS-based Monolithic Bidirectional Switch

We demonstrate the first enhancement-mode (E-mode) vertical GaN-on-Si monolithic bidirectional switch (M-BDS). The M-BDS employs a pair of anti-series connected vertical GaN MOSFETs with integrated freewheeling quasi junction-barrier Schottky (JBS) diodes, in which Nitrogen ions were implanted at the bottom/sidewall of the trenches to shield the Schottky anode from high electric field, resulting in state-of-the-art breakdown voltage (BV) exceeding 600 V in both polarities. Furthermore, the vertical GaN topology combines the merits of E-mode trench MOSFETs and low-voltage-drop Schottky diodes, enabling a high threshold voltage (VTH) of 3.5 V in transistor mode and a low turn-on voltage (VON) of 0.5 V in diode mode, respectively. These results underscore great potential of cost-effective vertical GaN-on-Si transistors as building blocks for high-performance bidirectional switches.