INFLUENCE OF THE SILICON-NITRIDE OXIDATION ON THE PERFORMANCES OF NCLAD ISOLATION

In order to study NCLAD isolation structures, a silicon nitride oxidat ion model has been studied and implemented in the process simulation p rogram IMPACT-4. Comparing the models proposed by Kamins, Enomoto and Deal and Grove (DG), it appears that the DG model is the best trade-of f between accuracy and easiness of implementation. The calibration aga inst one-dimensional experimental data has been performed and reveals an excellent agreement, The use of this new modeling capability shows that the oxidation of silicon nitride cannot be neglected when optimiz ing a NCLAD structure. As a result, it has been possible to improve th e topography of the oxidation stack of a recessed NCLAD structure in o rder to obtain the minimum bird's-beak punchthrough [1,2]. (C) 1998 El sevier Science Ltd. All rights reserved.