Temperature-dependent electrical transport properties of (Au/Ni)/n-GaN Schottky barrier diodes

Abstract

The temperature-dependent electrical properties of (Au/Ni)/n-GaN Schottky barrier diodes (SBDs)have been investigated in the wide temperature range of 40–400K. The analysis of the main electrical characteristics such as zero-bias barrier height (ΦB0), ideality factor (n) and series resistance (Rs) were found strongly temperature dependent. Such behavior is attributed to barrier inhomogeneities by assuming a Gaussian distribution (GD) of barrier heights (BHs) at the interface. It is evident that the diode parameters such as zero-bias barrier height increases and the ideality factor decreases with increasing temperature. The values of series resistance that are obtained from Cheung׳s method are decreasing with increasing temperature. The temperature dependence of Schottky barrier height (SBD) and ideality factor (n) are explained by invoking three sets of Gaussian distribution of (SBH) in the temperature ranges of 280–400K, 120–260K and 40–100K, respectively. (Au/Ni)/n-GaN Schottky barrier diode have been shown a Gaussian distribution giving mean BHs (Φ¯B0) of 1.167, 0.652 and 0.356eV and standard deviation σs of 0.178, 0.087 and 0.133V for the three temperature regions. A modified ln(I0/T2)−q2σ2/2k2T2 vs. 1/kT plot have given Φ¯B0 and A⁎ as 1.173eV and 34.750A/cm2K2, 0.671eV and 26.293A/cm2K2, 0.354eV and 10.199A/cm2K2, respectively.