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

Abstract

The authors model the capacitance-voltage (CV) behavior of In0.53Ga0.47As 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.