Explanation of Soft and Hard Breakdown and Its Consequences for Area-Scaling

Mapping the post breakdown current of larger area, ultrathin test capacitors to that of small area transistor is critically important for long term reliability projection of MOSFET circuits. This work presents, for the first time, a consistent theory that clarifies the area scaling of soft breakdown, and that explains how soft breakdown depends on stress current, oxide thickness, and backgate bias. The model also provides the first explanation of the puzzling bimodal failure distribution, and illustrates the fundamental limitations of the popular 1/2 CV sup 2 model. Predictions of this new model are experimentally confirmed to validate the theory.