Ultra-low turn-on voltage quasi-vertical GaN Schottky barrier diode with homogeneous barrier height

Abstract

Quasi-vertical Schottky Barrier Diodes (SBDs) with near to ideal turn-on voltage and ideality factor (n) of 1.02, were fabricated on a GaN on Si substrate. The average turn-on voltage and on-resistance values were found to be 0.23 ± 0.005 V (at 1 A/cm2) and 1.76 ± 0.11 mΩcm2, respectively with diode series resistance of 11 Ω. The analysis of the current–voltage curve revealed a temperature-independent barrier height, however the capacitance–voltage method showed a negative temperature coefficient. This discrepancy is discussed in the paper. Variable range hopping through dislocations is shown to be the dominant reverse current leakage mechanisms identified in the fabricated diode, with a characteristic temperature, T0 of 2 × 1010 K.