Temperature dependence of barrier height inhomogeneity in β -Ga2O3 Schottky barrier diodes

Abstract

From an analysis of Pd contact Schottky diodes fabricated on (100) β-Ga2O3 wafers, in combination with data extracted from published work, we show that the barrier height inhomogeneity commonly observed in β-Ga2O3 Schottky diodes has a strong correlation to the temperature. For doping of ∼5 × 1017 cm−3, the barrier height arising from an inhomogeneous contact continues to increase to a temperature of ∼440 K followed by a decrease upon a further increase in temperature, which is commonly attributed to the bandgap narrowing of the semiconductor referred to as the Varshni shift. At this regime, Schottky characteristics representing close to homogeneous behavior is obtained. Thus, a device under normal operating conditions in a system, which results in an elevated temperature, is expected to exhibit near-homogeneous electrical characteristics.