FORCED-CONVECTION IN VERTICAL BRIDGMAN CONFIGURATION WITH THE SUBMERGED HEATER

Ga-doped Ge single crystals were grown in vertical Bridgman configurat ion, using the submerged heater method (SHM). When used without rotati on. the submerged heater drastically reduces convection at the solid-l iquid interface. When the submerged heater is set in to rotation or os cillatory rotation, it acts as a centrifugal viscous pump, inducing fo rced a convection (radial-inward flow) along the interface. The flow p roduced by a rotation and oscillatory rotation of the submerged heater was visualized using a 1:1 scale model. The vigorous mixing produced by the oscillatory rotation creates a nearly perfectly stirred melt, a nd yields a uniform lateral distribution of the dopant. The crystals w ere free of unintentionally produced striae.