High voltage GaN Schottky rectifiers

Mesa and planar GaN Schottky diode rectifiers with reverse breakdown voltages (V/sub RB/) up to 550 and >2000 V, respectively, have been fabricated. The on-state resistance, R/sub ON/, was 6 m/spl Omega//spl middot/cm/sup 2/ and 0.8 /spl Omega/ cm/sup 2/, respectively, producing figure-of-merit values for (V/sub RB/)/sup 2//R/sub ON/ in the range 5-48 MW/spl middot/cm/sup -2/. At low biases the reverse leakage current was proportional to the size of the rectifying contact perimeter, while at high biases the current was proportional to the area of this contact. These results suggest that at low reverse biases, the leakage is dominated by the surface component, while at higher biases the bulk component dominates. On-state voltages were 3.5 V for the 550 V diodes and /spl ges/15 for the 2 kV diodes. Reverse recovery times were <0.2 /spl mu/s for devices switched from a forward current density of /spl sim/500 A/spl middot/cm/sup -2/ to a reverse bias of 100 V.