Electrical conduction in platinum–gallium nitride Schottky diodes

Gallium nitride is a highly promising wide band gap semiconductor with applications in high power electronic and optoelectronic devices. Among the devices considered for high power generation is the ubiquitous field-effect transistors which require Schottky barriers for modulating the channel mobile charge. It is in this context that we have undertaken an investigation of likely metal-GaN contacts. Here we report on the electrical conduction and other properties of Pt–GaN Schottky diodes. These Schottky diodes were fabricated using n-GaN grown by the molecular beam epitaxy method. Both capacitance–voltage and current–voltage measurements have been carried out as a function of temperature to gain insight into the processes involved in current conduction. Based on these measurements, physical mechanisms responsible for electrical conduction at low and high voltages and temperatures have been suggested. Schottky barrier height determined from the current–voltage and capacitance–voltage measurements is close to 1.10 eV.