A simple technique to determine barrier height change in gate oxide caused by electrical stress

Charge trapping in the gate oxide and at the interfaces caused by electrical stress may lead to changes of both the oxide field and the shape of tunneling barrier. In this study, a simple technique based on the analysis of a small change in the Fowler-Nordheim (FN) tunneling current has been developed to quantitatively examine the changes of the effective barrier height and the electric field at the tunneling interface. A power-law dependence of the changes of both the barrier height and the electric field on the stress time is observed.