Effects of ambient gases on current-voltage characteristics of Pt-GaN Schottky diodes at high temperatures

The electrical characteristics of a Pt Schottky barrier to n-type GaN grown by metalorganic chemical vapor deposition and the effects of ambient gases on their properties have been investigated at elevated temperatures of up to 600 degreesC. The current-voltage (I-V) characteristics of Schottky diodes remained stead at high temperatures of up to 600 degreesC, although the rectifying ratio decreased with a rise in temperature, The I-V characteristics of Pt-GaN Schottky diodes depended on the ambient gases. Hydrogen decreases the barrier height of Pt-GaN Schottky diodes, whereas oxygen increases it. The barrier height changed significantly in the temperature range from 100 to 400 degreesC due to the change of atmosphere from H-2 to O-2.