Monte Carlo sphere model for effective oxide thinning induced extrinsic breakdown

The Monte Carlo sphere model is extended to deal with the extrinsic time-de pendent-dielectric-breakdown (TCDB) by incorporating the well-known "effect ive oxide thinning" concept. Percolation simulation, based on this model fo r the first time, evidences that the process defects induced extrinsic TDDB is also statistical in nature as is the intrinsic one, and is characterize d by a probability function defining local oxide thinning. The experimental bimodal or even multimodal characteristics can be reproduced accordingly. Furthermore, the simulation results in the extrinsic regime are found to be sample-size (i.e., the total number of samples that span the breakdown sta tistics) dependent, suggesting that care should be taken when evaluating th e extrinsic TDDB data in a real manufacturing process.