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°C. The current–voltage (I–V) characteristics of Schottky diodes remained steady at high temperatures of up to 600°C, 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°C due to the change of atmosphere from H2 to O2.