p -GaN Gate Power Transistor With Distributed Built-in Schottky Barrier Diode for Low-loss Reverse Conduction

A 700-V normally-off p -GaN gate power transistor with distributed built-in Schottky barrier diode (SBD) is demonstrated in this work. The transistor cell and diode cell are alternately arrayed along the device width and are locally isolated using ion implantations. The built-in SBD provides a low reverse turn-on voltage which is independent of the threshold voltage and gate bias of the transistor. Compared to the two-device scheme consisting of an anti-parallel p-GaN gate HEMT/SBD pair, the proposed transistor exploits the common access region in both forward conduction and reverse conduction, thus a significant reduction in chip area is obtained.