High-performance 500 v quasi- and fully-vertical GaN-on-Si pn diodes

Abstract

This letter demonstrates quasi- and fully vertical GaN-on-Si pn diodes with record performance. The optimized device structure employs a highly conductive (ND > 1020 cm-3) current collecting layer and a lightly carbon-doped drift layer. With this optimization, a differential specific on-resistance (RON) of 0.8-1 m Ω·cm2, a breakdown voltage (BV) over 500 V, and a high forward current (∼kA/cm2) were demonstrated. Excellent RON and BV performance up to 300 °C were also obtained. A small reverse recovery time of 50 ns was demonstrated under switching conditions. With Baliga's figure of merit over 0.32 GW/cm2, these devices show the great potential of low-cost GaN-on-Si vertical devices for future power applications.