GaAs MIS structures with SiO2 using a thin silicon interlayer

The introduction of a pseudomorphic Si interlayer, about 1.0 nm thick, is found to dramatically improve the MIS characteristics of the SiO₂-GaAs system. Quasistatic and high-frequency capacitance/voltage data from such a novel capacitor structure on n -GaAs indicate that the surface of the GaAs is swept from inversion to accumulation. X-ray photoelectron spectroscopy and ion scattering spectroscopy confirm the presence of the Si layer and its complete coverage of the GaAs surface. The Si layer minimises the formation of any detrimental native oxides and thus controls the chemical nature of the GaAs surface. This approach has implications in the development of metal-insulator-semiconductor systems in general