A consistent model for time dependent dielectric breakdown in ultrathin silicon dioxides

The stress voltage dependence of oxide degradation has been studied utilizing the "A-mode" stress induced leakage current. Although the defect site generation rate follows the 1/E-model, T/sub BD/ (time to breakdown) seems to follow the E-model. At low voltage region where T/sub BD/ deviates from the 1/E-model, Q/sub BD/ (electron fluence to breakdown) becomes constant in stead of Q/sub p/ (hole fluence to breakdown). Based on these results, the Dominant Carrier Change model has been proposed. This model allows a more aggressive use of oxide film, i.e., thinner thickness and higher operating voltages.