A consistent model for the hard breakdown distribution including digital soft breakdown: the noble art of area scaling

A new statistical model is presented for the hard breakdown distribution including digital soft breakdown as observed on ultra-thin gate dielectrics, allowing for consistent area scaling of experimental time dependent hard breakdown data and extrapolation to low percentiles. It predicts a smaller reliability margin than would be obtained through direct convolution of the SBD and wearout distributions. The paper reveals that failure criteria based upon multiple soft breakdowns claiming extra reliability margin have to be treated with caution, as they lead to area dependent specifications.