Study of Local Silicon Oxidation with Calibrated Nitride Model

Typical 2D effects such as oxide thinning and bird´s beak size decrease with nitride masks and windows size reduction are observed in submicron isolation structures. Such phenomena depend on the stresses generated by the oxidation process and consequently on the mechanical properties of the IC-materials. In this paper, an elastovisco-plastic modelling of the silicon oxidation is used for the calibration of the nitride properties and applied to various LOCOS processes.