Deep-level distributions in hydrogenated amorphous silicon

Abstract

Electronic defect levels in hydrogenated amorphous silicon have been measured by transient-voltage spectroscopy. On Schottky-barrier diodes with n-type conductivity, the deep-level distribution displays a broad peak centered ∼0.8 eV below the conduction-band mobility edge. On metal-insulator-silicon capacitors with a silicon-dioxide gate dielectric, the saturated voltage transient arises from interfacial and bulk gap states. By comparison, measurements on silicon-nitride insulated capacitors demonstrate charge injection and trapping in the dielectric.