RESUMEN

A simple homogeneous reaction model in one dimension is presented in the context of silicon oxidation. We investigate two different (canonical) regimes for the oxidant diffusivity and show how these lead in the limit of fast bulk reactions to distinct sharp interface models for oxidation. The resulting heterogeneous models are moving boundary problems which correspond to the classical Stefan problem or to the Stefan problem with kinetic undercooling. The results are relevant for more general reactions but illustrate some of the peculiarities associated with silicon oxidation.

RESUMEN

A model for the isolation oxidation of silicon, an important process in the fabrication of many integrated circuits, is presented. The problem is two-dimensional with two moving boundaries. Oxidant diffusion is modelled as quasi-steady state and the oxide is assumed to be a Newtonian fluid. Asymptotic techniques are applied to the case of reaction controlled oxidation, which occurs for sufficiently thin oxides.