High Temperature Electronic Properties of a Microwave Frequency Sensor – GaN Schottky Diode

Abstract

The potential energy barrier height, depletion layer thickness and junction capacitance properties of a microstructure GaN Schottky diode as a microwave frequency sensor have been estimated at extreme temperature (300 – 950K), under applied external bias (0 – 20V) by computational method based on the analytical expression obtained by the application of rule of thumb on the existing energy gap of n-GaN and existing solutions (depletion thickness and capacitance) of Poisson’s equation. The results of the calculation shown that the barrier height decreases as the temperature increases, but abrupt increase in the barrier height was observed as the temperature continues to increase above 900K. This behaviour may be linked to thermal stability demonstrated by n-GaN Schottky diode at high temperature. Also, the depletion thickness decreases as the temperature increases and the capacitance decreases as the bias increases. The decrease of the capacitance is much at high temperature under the same applied bias condition. The GaN Schottky diode can be employed as microwaves frequency sensor at very high temperature.

Keywords: Barrier height, Depletion layer thickness, Junction capacitance, n-GaN Schottky diode, microwave sensor, high temperature.