On the interface state density at In0.53Ga0.47As/oxide interfaces

Abstract

The authors model the capacitance-voltage $\left(CV\right)$ behavior of ${\text{In}}_{0.53}{\text{Ga}}_{0.47}\text{As}$ metal-oxide-semiconductor (MOS) structures and compare the results to experimental $CV$ -curves. Due to the very low conduction band density of states, ideal III-V MOS structures should present an asymmetric $CV$ behavior, with lower accumulation capacitance on the conduction band side. The absence of this asymmetric $CV$ shape in experimental $CV$ curves points toward the presence of additional states inside the conduction band at the oxide-semiconductor interface. Comparisons between the model and experimental data allow the determination and approximate quantification of a large acceptorlike interface state density above the conduction band edge energy.