Temperature dependence of electrical parameters of the Cu/n-Si metal semiconductor Schottky structures

Abstract

The main electrical characteristics of Cu/n-Si metal-semiconductor structures have been investigated in the temperature range 50 K to 310 K using current–voltage (I–V) and capacitance–voltage (C–V) measurements. It has been showed that the values of ideality factor and barrier height increase with increase in temperature and are clarified by invoking three different set of Gaussian distributions (GD) of barrier height at 50–160 K, 160–220 K, and 220–310 K. The values of ideality factor and barrier height for the Cu/n-Si metal-semiconductor structures were obtained as 1.435 and 0.487 eV at 50 K, 1.399 and 0.704 at 120 K, 2.192 and 0.701 at 220 K, and 4.286 and 0.759 eV at 310 K, respectively. This results showed fairly that in presence of inhomogeneity at metal semiconductor (MS) interface. The double Gaussian distribution of the temperature dependent I–V characteristics of the Cu/n-Si metal-semiconductor structures barrier diode gave the mean barrier heights of 0.532, 0.638 and 0.816 eV and standard deviations (σo) of 3120 mV, 37 mV and 53 mV, respectively. Thus, the values of the mean barrier height have been verified with the modified ln(I0/T2)−q2σ2/2k2T2 versus (kT)−1 plot which belongs the three different temperature regions. Furthermore, it was showed that a noticeable increase of the saturation current from 1.978 × 10–46 to 3.973 × 10–8 A, (from 50 K to 310 K). The increase in saturation current after temperature was attributed to the presence of interface states created by temperature induced defects.