Nonlinear Phenomena in Complex Systems, 2000, Vol.3, No.3, pp.289--292

NONLINEAR PHENOMENA IN COMPLEX SYSTEMS
An Interdisciplinary Journal

2000, Volume 3, Number 3, pp.289--292

On the Origin of Bigscale Longitudinal Oscillations of the Oxygen and Doped Impurity Concentration in Silicon Crystals Grown by the Czochralski Method.
V.V. Litvinov, A.N. Petuch, Ju.M. Pokotilo

The frequency spectrum of the longitudinal concentration oscillations of the oxygen in silicon mono crystals doped by phosphorus was investigated. Two modes with independent frequencies f1 = 1.6 x 10^-3 and f2 = 6.0 x 10^-4 Hertz were found under quasi-periodical regime of melt convection. Comparison of oxygen and phosphorus concentration oscillations allowed to make connection between f1 mode and convection roll oscillations along temperature gradient which results in periodical change of both impurity segregation coefficients. Lower frequency mode f2 is associated with non-stationary transfer of the oxygen concentration which results in wave-like displacement of melt convection rolls across temperature gradient. Oxygen distribution coefficient in silicon was estimated about 0.25 using comparison analysis of the oxygen and phosphorus profiles.
Key words: melt convection, longitudinal concentration oscillations, silicon crystals doped by phosphorus.

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