Temperature-dependent electrical characteristics of bulk GaN Schottky rectifier

• DOI: 10.1063/1.2425004
• Publication Date: 2007-02-03T06:30:43Z
• Authors: Yi Zhou; Dake Wang; Claude Ahyi; Chin-Che Tin; John Williams; Minseo Park; N. Mark Williams; Andrew Hanser; Edward A. Preble
• Keywords: 0103 physical sciences; 01 natural sciences

The temperature-dependent electrical characteristics of Schottky rectifiers fabricated with a SiO2 field plate on a freestanding n− gallium nitride (GaN) substrate were reported in the temperature range of 298–473K. The Schottky barrier heights evaluated from forward current-voltage measurement revealed an increase of Schottky barrier height and series resistance but a decrease of ideality factor (n) with increasing temperature. However, the Schottky barrier heights evaluated from capacitance-voltage measurement remained almost the same throughout the temperature range measured. The Richardson constant extrapolated from ln(J0∕T2) vs 1∕T plot was found to be 0.029Acm−2K−2. A modified Richardson plot with ln(J0∕T2) vs 1∕nT showed better linearity, and the corresponding effective Richardson constant was 35Acm−2K−2. The device showed a high reverse breakdown voltage of 560V at room temperature. The negative temperature coefficients were found for reverse breakdown voltage, which is indicative of a defect-assisted breakdown.