Analysis of temperature dependent forward characteristics of Ni/(201) β-Ga₂O₃ Schottky diodes

In this paper, the temperature dependence of the turn-on characteristics of Schottky barrier diodes fabricated on (201) oriented n-type β-Ga₂O₃ is reported. The barrier height (qΦ_bn) and ideality factor (n) for Ni- β-Ga₂O₃ was found to be 1.08±0.05 eV and 1.19 respectively at room temperature. The effective Richardson constant (A∗∗) is determined to be 42.96 A cm^-2 K^-2, in close agreement with the theoretical value. At low temperatures (85-273 K), the current-voltage characteristics reveal a strong temperature dependence of Schottky barrier heights and ideality factors and a corresponding deviation from the barrier height extracted from capacitance-voltage measurements. A detailed analysis is presented, which suggest that these effects can be attributed to a large barrier inhomogeneity at metal/β-Ga₂O₃ interfaces, possibly resulting from interfacial defects, which can be modeled using a potential fluctuation model.