Novel Schottky contacts to n-type gallium nitride: Microelectronic device applications

Group III-V wide band gap semiconductor particularly GaN received a great deal of attention in the past decade due to its potential for the realization of electronic and optoelectronic devices. Its wide band gap, high break down field, and high electron saturation velocity also make it an attractive candidate for the development of electronic devices operating at high temperature, high power and high frequency devices such as light emitting diodes, laser diodes, metal-semiconductor field effect transistors and high electron mobility transistors. Especially, the performance and reliability of these devices have been improved with high quality ohmic and Schottky rectifiers. However, larger leakage current through Schottky rectifiers adversely affects the operation, power consumption, noise and reliability of devices. Hence, Schottky rectifier for GaN with ultra low leakage current is one of the challenges to their use in optoelectronic and electronic devices. Therefore, it is necessary to obtain a high Schottky barrier height at the metal/semiconductor (MS) interface to reduce the leakage current and to improve break down voltage in Schottky diodes.