Low-frequency capacitance-voltage study of hydrogen interaction with Pt-AlGaN/GaN Schottky barrier diodes

We have investigated the interaction of hydrogen with Pt-AlGaN/GaN Schottky barrier diodes (SBDs) using a lowfrequency capacitance-voltage (C-V) technique. At a frequency of 1 kHz, the C-V curve in hydrogen shifts toward negative bias values as compared with that in nitrogen. As the frequency decreases from 1 kHz to 1 Hz, the capacitance in hydrogen significantly increases and an oscillation of the capacitance is observed. These C-V characteristics are quite anomalous and have not been reported yet, suggesting the formation of an interfacial polarization which could be attributable to hydrogen-related dipoles. The oscillation of the capacitance may be related to the alignment of the dipoles.