Transient effects of positive oxide charge on stress-induced leakage current in tunnel oxides

Abstract

The role of positive oxide charge in excess low-level leakage current in tunnel oxides induced by Fowler/Nordheim stress is investigated. A correlation between stress-induced gate current and substrate current in an n-channel metal-oxide-semiconductor field-effect transistor is observed. Both the gate current and the substrate current exhibit a significant transient effect. The mechanisms of the stress-induced currents and their field dependence are explored. Positive oxide charge tunnel detrapping is found to be the cause of the observed transient behavior in the two currents. The stress-created positive oxide charge can be significantly annealed by substrate hot electron injection. (C) 1999 American Institute of Physics. [S0003-6951(99)02226-3].