The effect of a magnetic field on the flux of a contaminant dissolving into the crucible wall boundary layer in Czochralski crystal growth

Abstract

In this paper we consider the effect of various configurations of magnetic field on an idealised model of the crucible sidewall boundary layer in a Czochralski crystal growth melt. We determine the effect of these different configurations on the fluid flow in a boundary layer adjacent to the wall. From this analysis we are able to determine the flux of a contaminant, such as oxygen, produced by a chemical reaction at the wall into the bulk of the melt. We show that a magnetic field may increase or decrease the contaminant flux across the momentum boundary layer. Although, in general the magnetic field acts to inhibit the flow in the boundary layer, and thus reduce the contaminant transport into the bulk of the melt, the nature of the dependence of the rate of contaminant production on temperature at the wall can act to increase the overall contaminant transport into the melt.