High reverse breakdown voltage Schottky rectifiers without edge termination on Ga2O3

Abstract

Vertical geometry Ni/Au-beta-Ga2O3 Schottky rectifiers were fabricated on Hydride Vapor Phase Epitaxy layers on conducting bulk substrates, and the rectifying forward and reverse current-voltage characteristics were measured at temperatures in the range of 25-100 degrees C. The reverse breakdown voltage (V-BR) of these beta-Ga2O3 rectifiers without edge termination was a function of the diode diameter, being in the range of 920-1016V (average value from 25 diodes was 975 +/- 40 V, with 10 of the diodes over 1 kV) for diameters of 105 mu m and consistently 810V (810 +/- 3V for 22 diodes) for a diameter of 210 mu m. The Schottky barrier height decreased from 1.1 at 25 degrees C to 0.94 at 100 degrees C, while the ideality factor increased from 1.08 to 1.28 over the same range. The figure-of-merit (V-BR(2)/R-on), where R-on is the on-state resistance (similar to 6.7 m Omega cm(2)), was approximately 154.07 MW.cm(-2) for the 105 mu m diameter diodes. The reverse recovery time was 26 ns for switching from +5V to -5V. These results represent another impressive advance in the quality of bulk and epitaxial beta-Ga2O3. Published by AIP Publishing.