Finite-Element Simulation of Local Oxidation of Silicon

In this paper, various numerical models for finite element simulation of local oxidation of silicon are investigated. The simplest one contains linear diffusion of oxidizing species and elastic displacements of dioxide layers. The limitations of this model and the influences of pad-oxide and nitride mask thicknesses as well as temperature are illustrated by computer simulations. The local effects of mechanical stresses on the diffusion mechanism are simulated and an elasto-visco-plastic model is proposed so that a wide range of temperatures can be covered. Finite-Element simulation of semi-Rox, full-Rox, and SILO processes are presented.