Investigation of temperature dependent electrical properties of Ni/Al0.26Ga0.74N Schottky barrier diodes

Abstract

The current–voltage (I–V) characteristics of the Ni/Al0.26Ga0.74N Schottky barrier diodes (SBDs) were measured in the temperature range of 100–310K by the step of 10K. The forward I–V characteristics were analyzed on the basis of the thermionic emission theory. The characteristics of diode parameters such as the Schottky barrier height (SBH) and the ideality factor were investigated as a function of temperature. An experimental SBH value of about 1.021eV was obtained for the Ni/Al0.26Ga0.74N SBD at 300K. The experimental results show that the values of the ideality factor decrease while the values of the SBH increase with increasing temperature. The temperature dependence of the SBH was explained on the basis of a thermionic emission mechanism with the Gaussian distribution of the SBHs due to the SBH inhomogeneities at the metal–semiconductor interface. The values of the mean barrier height Φ¯b0 and the standard deviation σs0 were 1.362eV and 133meV in the temperature range of 210–300K, 1.204eV and 111meV in the temperature range of 100–210K, respectively. The modified Richardson plots according to inhomogeneity of the SBHs have a good linearity in the corresponding temperature range. The values of Richardson constant A* were found to be 31.46Acm−2K−2 and 33.36Acm−2K−2 in the temperature ranges of 210–310K and 100–210K, respectively. The obtained Richardson constant values are in good agreement with the theoretical value of 34.56 Acm−2K−2 known for n-type Al0.26Ga0.74N.