Flow Transitions in Melts during Czochralski Growth of GaAs Single Crystal
CZ法砷化镓单晶生长中熔体流动状态转换

The time-dependent and three-dimensional turbulent mathematics model is established for the flow and heat transfer of GaAs melt in the Czochralski system. The flow transitions in the melts are predicted. When the combined buoyancy and Marangoni forces induced by temperature gradient are comparable to the combined centrifugal and coriolis forces induced by crystal rotation, the flow in the melt is non-axisymmetric, and when either of them is dominant, the flow is axisymmetric. Baroclinic thermal wave is observed in the non-axisymmetric flow. The mechanism of to non-axisymmetric flow is the baroclinic instability. The flow regime diagrams classifying the flow mode under different conditions are obtained. The calculated results can be taken as a reference for growth of GaAs single-crystal with high quality.