Interface State Density in Atomic Layer Deposited SiO2/β-Ga2O3 ((2)over-bar01) MOSCAPs

The interface state density (D-it) at the interface between beta-Ga2O3 ((2) over bar 01) and atomic layer deposited (ALD) SiO2 dielectric is extracted using Terman method and conductance method. The effect of the different surface treatments on the extracted D-it was also studied. It is observed that the extracted D-it of 6 x 10(11) cm(-2)eV(-1) for the sample with no surface treatment is lower than hydrofluoric and hydrochloric acid treated samples. Low D-it sample shows narrow peak in the conductance method, suggesting a smooth interface. The extracted low D-it makes ALD SiO2 an attractive candidate for future Ga2O3 power devices.