Transport properties of Gallium Phosphide based Schottky contact with thin insulating layer

The current-voltage (I-V) characteristics of Au/n-GaP Schottky barrier diode was analyzed in wide temperature range of 220-400 K. The conduction mechanism in the low bias region, except for 220 K and 240 K, was identified as tunneling (TN). Nevertheless, thermionic emission (TE) becomes dominant as the voltage increases. The diode parameters were evaluated in this region by TE model incorporating the concept of thin insulating layer. The series resistance (Rs) of the device was found to decrease with increase in temperature. In the 220-320 K temperature range, as reported for most of the Schottky diodes, the zero-bias barrier height (ϕb0) decreases and the ideality factor (η) increases with the decrease of temperature. The value of modified Richardson constant (A**) obtained agrees well with the theoretical value. However, in the 320-400 K range, the variation of η and ϕb0 with temperature shows opposite trend, which is speculated as due to the change in conduction pattern by the temperature induced modifications at the interface.