Effects of surface traps on breakdown voltage and switching speed of GaN power switching HEMTs

Abstract

As a competitive candidate for power switching electronics, GaN has slightly wider bandgap, higher electric strength, and higher saturated velocity than SiC. An insulating-gate structure GaN HEMT with a breakdown voltage of 1.3 kV was fabricated with a specific on-resistance of 1.7 m/spl Omega/.cm/sup 2/. State-of-the-art power device figure of merit of V/sub BR//sup 2//R/sub on/= 9.94/spl times/10/sup 8/ [V/sup 2//spl middot//spl Omega//sup -1/ cm/sup -2/] was achieved on this device. Device analysis shows that the surface traps play a dominant role in breakdown voltage and switching speed. High switching speed was realized on the kilo-volts devices by adoption of double gate dielectrics.