Breakdown simulation in thin dielectric films based on DLA model

In metal oxide semiconductor capacitors subjected to electrical stress the dielectric breakdown is due to the creation of new electronic traps, forming a conductive path between the gate electrode and substrate. The breakdown phenomenon depends on the dielectric thickness and the number and the nature of traps needed to form a perocative path across the dielectric. Here we tried an approach to modeling the dielectric degradation based on fractal distribution of traps. The fractal pattern of cluster of traps formation is produced by algorithm based on difussion limited aggregation (DLA) model, used in the literature to model irreversible colloidal aggregation. In our approach trap generation and migration is not random and we introduced several parameters that simulates the realistic situation. The results obtained by this model are compared with the Weibull statistics used to desccribe the dielectric film failure. Finally the results of the modelling are compared with the experimental data obtained on thin dielectrc film breakdown.