Instability of the buoyancy driven convection in Si melts during Czochralski crystal growth

We study conditions under which the buoyancy driven convection in Czochralski systems will be unstable. The variable parameters are: the crucible radius R sub(c), the crystal radius R sub(D), the melt depth H, and the temperature difference between the crucible wall and the solid-liquid interface De...

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Bibliographic Details
Published in:Journal of crystal growth 1989-09, Vol.97 (1), p.42-49
Main Authors: Mihelcic, M, Wingerath, K
Format: Article
Language:English
Online Access:Get full text
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Summary:We study conditions under which the buoyancy driven convection in Czochralski systems will be unstable. The variable parameters are: the crucible radius R sub(c), the crystal radius R sub(D), the melt depth H, and the temperature difference between the crucible wall and the solid-liquid interface Delta T, respectively. In order to initiate the instability of the flow we impose a small temperature disturbance over the axisymmetric temperature distribution at the crucible wall. 36 cases are simulated numerically in order to make inferences about this instability. It is shown that (1) the buoyancy driven flow is highly unstable for all nearly real growing conditions, (2) the instability of the flow depends on all varied parameters, but stronger on the melt depth than on the other parameters.
ISSN:0022-0248
DOI:10.1016/0022-0248(89)90245-5