Cycling of defects between trapped negative charge and interface states at the Si-SiO2 interface

Abstract

We have investigated the states produced at the Si-SiO2 interface by Fowler–Nordheim tunneling and by UV photoinjection at low temperature (90 K). After the interface states are generated, subsequent application of a negative gate bias (5–6 MV/cm) converts them entirely into trapped negative charge. The reverse conversion into interface states occurs if a positive gate bias (5–6 MV/cm) is applied. Cycling of the defects between interface states and trapped negative charge is observed in both experiments. The data strongly suggest that both low-temperature Fowler–Nordheim tunneling and UV photoinjection generate essentially the same structural defect at the interface between Si and SiO2.