Influence of localized latent defects on electrical breakdown of thin insulators

Electrical breakdown in thin SiO/sub 2/ films was measured with different techniques at different electric fields. It is shown that oxide reliability is affected by the presence of latent defects requiring a certain time to develop and evolve towards a destructive stage. As such a time is weakly dependent on applied fields, breakdown is not adequately detected by accelerated tests. It is shown that, due to the localized nature of breakdown, meaningful relationships between measured parameters able to clarify the microscopic nature of oxide failure are not easy to establish.>