A statistical model of oxide breakdown based on a physical description of wearout

The breakdown of oxides has been related to wearout. A model has been developed that described the statistics of breakdown in terms of the wearout that occurred prior to breakdown. TDDB distributions given in the literature were accurately simulated (i) for area dependence, (ii) for both constant voltage and constant current stressing, and (iii) for multi-modal distributions. Defect related breakdown was incorporated by introducing the concept of "degree of wearout". A possible method for determining the reliability of an oxide at operating voltages from the accelerated test results has been developed.<>