Analysis of oxide breakdown mechanism occurring during ESD pulses

In new technologies, concern for oxide breakdown during ESD (ElectroStatic Discharge) is becoming more and more important. It is usually evaluated using the classical 1/E law for the time to breakdown. In this study, we report different experiments demonstrating that this model for the time to breakdown need to be improved in the case of ESD stresses. A model for the conduction at these high current densities is proposed. The times to breakdown are analyzed on a large range of current densities. We show that we must take into account the effects of current crowding, electrical breakdown, temperature increase during the pulse and thermal breakdown to understand the failure mechanisms. A model is proposed to evaluate the heating during the ESD pulses and to predict the oxide strength.