(Invited) Interface Trap Densities and Admittance Characteristics of III-V MOS Capacitors

Abstract

High-k/III-V interfaces in metal-oxide-semiconductor capacitor structures with In0.53Ga0.47As channels exhibit certain admittance characteristics that are almost universally observed, independent of the specific high-k material or deposition technique used. These include a "hump" in the capacitance-voltage curves at negative biases (depletion region) and low frequencies for n-type channels, and pronounced frequency dispersion in accumulation. The paper discusses both features in the context of the high density of non-uniformly distributed interface trap states in the semiconductor band gap that is typical of these interfaces.