Simulation of spatially-heterogeneous oxygen precipitation in silicon with allowance for internal mechanical stresses

Abstract

A new model of the kinetics of oxygen precipitation in silicon, which allows for the effect of internal mechanical stresses that arise at the boundaries of precipitation particles on the speed of oxygen transport and silicon oxidation reactions, is developed based on an approach previously proposed by authors. Temporal variations of the spatial distribution of oxygen in a silicon plate are calculated under conditions of the formation of precipitation particles. Dependences of the width of a defect-free zone formed in a plate on the time and temperature of the annealing are obtained. This is an important characteristic of the formation of an internal getter in carriers. The allowance for internal mechanical stresses is shown to result in decreasing the rate of the widening of a defect-free zone, which agrees with the experiment data. The results can be used to optimize the formation of an internal getter.