Model of diffusional layer growth of new compounds in silicon-chromium wafers

The growth of chromium silicide and chromium oxide layers within a chromium film deposited on a single-crystal silicon substrate is examined. Possible mechanisms underlying this phenomenon are discussed. A physical model is proposed to explain the linear and parabolic growth stages of chromium silicide, as well as the kink in the linear stage and the correlation of this kink with the formation of the chromium oxide layer. To describe this phenomenon, a system of coupled equations accounting for diffusion and chemical reactions in media with moving boundaries was formulated. Approximate solutions were derived, and an algorithm for obtaining them is presented. Parameters characterising layer growth and critical values corresponding to changes in growth regimes were determined. The calculated values are compared with experimental observations.