Operation up to 225°C of NiO/ β-(Al0.21Ga0.79)2O3 /Ga2O3 Heterojunction Lateral Rectifiers

Abstract

The characteristics of NiO/ β-(Al0.21Ga0.79)2O3 /Ga2O3 heterojunction lateral geometry rectifiers with the epitaxial layers grown by Metal Organic Chemical Vapor Deposition were measured over the temperature range from 25-225°C. The forward current increased with temperature, while the on-state resistance decreased from 360 Ω•cm2 at 25°C to 30 Ω.cm2 at 225°C. The forward turn-on voltage was reduced from 4 V at 25°C to 1.9 V at 225°C. The reverse breakdown voltage at room temperature was ~4.2 kV, with a temperature coefficient of -16.5 V/K. This negative temperature coefficient precludes avalanche being the breakdown mechanism and indicates that defects still dominate the reverse conduction characteristics. The corresponding power figures-of-merit were 0.27-0.49 MW.cm-2. The maximum on/off ratios improved with temperature from 2105 at 25°C to 3107 at 225°C when switching from 5 V forward to 0 V. The high temperature performance of the NiO/ β-(Al0.21Ga0.79)2O3 /Ga2O3 lateral rectifiers is promising if the current rate of optimization continues.