Hydrogen effect on Pt/Al2O3/GaN metal-oxide-semiconductor capacitors

Abstract

The effect of hydrogen on Pt/Al2O3/GaN metal-oxide-semiconductor capacitors was investigated by capacitance-voltage (C-V) measurements. The results showed that hydrogen exposure shifted the C-V curves towards the negative bias direction, indicating that hydrogen was incorporated into Al2O3 as a positive charge. Dry air exposure shifted the C-V curves back towards the positive bias direction more quickly than nitrogen did, which suggests that Pt has a catalytic function. Moreover, applying a negative bias to Pt resulted in faster shifts of the C-V curves back towards the positive bias direction. These results may suggest that hydrogen plays a critical role in post-metallization annealing.