Temperature-Dependent Leakage Current Characteristics of Homojunction GaN p-i-n Rectifiers Using Ion-Implantation Isolation

We report vertical GaN p-i-n rectifiers grown on a bulk GaN substrate. These planar GaN p-i-n rectifiers were implemented with Schottky field plates and buried-junction field terminations using ion implantation as a mean of device isolation. The 1130-μm-diameter GaN p-i-n rectifiers achieved a blocking voltage (BV) of 1.2 kV and an ON-state current drive of 10 A. A temperature-dependent OFF-state current study showed that the variable-range-hopping (VRH) conduction is dominant for devices operating at the temperature of less than 160 K, and multistep electron transition is responsible for the reverse-biased leakage at higher temperature. Further study suggested the leakage current arises from the deep centers formed through the ion-implantation damage that led to perimeter-dependent leakage currents in GaN p-i-n rectifiers using ion-implanted isolation approach.