On the effect of polarization relaxation on dielectric breakdown

Abstract

This article discusses the effect of polarization relaxation on dielectric breakdown. We establish analytical statistical Weibull distributions, taking into account the changing local electric field instead of the usual static field in acceleration models. The time dependence of the local field is expressed using the universal Curie–Von Schweidler law. The derived distribution fits well with various observations on time-to-breakdown statistical distributions. In the case of voltage square pulse alternative stress, the calculated time to breakdown follows a power law with stress frequency, regardless of the field dependence of the acceleration model, consistent with observations. The dielectric lifetime is longer compared to continuous voltage stress, as observed in transistors and integrated capacitors. The analytical expression of the power law exponent depends on the field acceleration model and polarization current. It matches well with the measured values for metal–oxide–semiconductor and metal insulator metal capacitors with different dielectrics. The power law exponent increases with the static dielectric constant. The Weibull shape factor is shown to be lower in the AC mode than in the DC mode, as observed. The AC signal duty factor effect decreases the lifetime in the AC mode. Finally, we demonstrate that the consequence of polarization relaxation also affects the lifetime in the DC mode. The acceleration factor and lifetime projections are close to power laws with the field, regardless of the static field dependence of the acceleration model.