Oxygen concentration inhomogeneity in the silicon melt of the czochralski single crystal growth system

Abstract

The momentum, heat and mass transfer in the silicon melt of the Czochralski crystal growth system were calculated with a three dimensional numerical simulation technique. Several types of non-axisymmetric profiles of velocities, temperature and oxygen concentration appeared in the melt with axisymmetrical boundary conditions. Since the asymmetric profiles and the rotations of fluid, temperatures and oxygen concentration fluctuated in the melt. The correlations between both fluctuations at the same point became larger, as the convection grew stronger. The calculation also showed that the temperature and oxygen concentration near the interface also fluctuated. The results suggested that the oxygen concentration could be considered one of the causes of the striation pattern in grown silicon single crystals.