Mechanisms for lateral solute segregation in edge‐defined film‐fed crystal growth

摘要

The extent of lateral dopant segregation across a crystal sheet produced by the edge‐defined film‐fed growth technique is set by the shape of the die and molten zone and by the intensity of the convection in the melt. Finite element calculations of the velocity and concentration fields for model melt shapes are used to separate the influences of growth rate, die geometry, melt height, tapering of the melt/gas interface, and curvature of the melt/solid phase boundary on lateral segregation. Curvature of the solidification front is most important when the melt height is large enough that the diffusion layer does not reach the die top. Surface‐tension‐driven convection induced by the axial temperature gradient dominates over the growth velocity and leads to qualitatively different lateral segregation patterns.