Analysis of temperature dependent forward characteristics of Ni/$\left(\overline{2}01\right)$β-Ga₂O₃ Schottky diodes

In this paper, the temperature dependence of the turn-on characteristics of Schottky barrier diodes fabricated on $\left(\overline{2}01\right)$ 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. (paper)