Current transport in Zn/p-Si(1 0 0) Schottky barrier diodes at high temperatures

Abstract

In this study, we have performed behavior of the non-ideal forward bias current–voltage ( I–V) and the reverse bias capacitance–voltage ( C–V) characteristics of Zn/p-Si (metal–semiconductor) Schottky barrier diode (SBDs) with thin interfacial insulator layer. The forward bias I–V and reverse bias C–V characteristics of SBDs have been studied at the temperatures range of 300–400 K. SBD parameters such as ideality factor n, the series resistance ( R S) determined Cheung's functions and Schottky barrier height, Φ b , are investigated as functions of temperature. The ideality factor n and R S were strongly temperature dependent and changed linearly with temperature and inverse temperature, respectively. The zero-bias barrier heights Φ b 0 ( I – V ) calculated from I–V measurements show an unusual behavior that it was found to increase linearly with the increasing temperature. However, the barrier height Φ b ( C – V ) calculated from C–V measurements at 500 kHz frequency decreased linearly with the increasing temperature. The correlation between Φ b 0 ( I – V ) and Φ b ( C – V ) barrier heights have been explained by taking into account ideality factors n and the tunneling factor ( α χ 1 / 2 δ ) in the current transport mechanism. Also, the temperature dependence of energy distribution of interface state density ( N SS ) was determined from the forward I–V measurements by taking into account the bias dependence of the effective barrier height. The higher values of n and R S were attributed to the presence of a native insulator on Si surface and to high density of interface states localized at semiconductor–native oxide layer (Si/SiO 2) interface.