Electrical stress-induced variable range hopping conduction in ultrathin silicon dioxides

Electrical stress-induced variable range hopping conduction is reported in the ultrathin silicon dioxides. The conduction is mediated by the localized states, including various trap sites and interface states induced by the electrical stressing. Based on the results, a model for the conduction mechanism of the ''B-mode'' stress-induced leakage current (B-SILC) is proposed. This model well explains the temperature dependence and large fluctuation of the B-SILC, which cannot be explained by the previous models for the B-SILC. Furthermore, an empirical expression for the current-voltage characteristics of the B-SILC is also proposed. (C) 1997 American Institute of Physics.