Effects of different crucible shapes on heat and oxygen transport during continuous Czochralski silicon crystal growth

The effects of different quartz crucible geometries on continuous Czochralski growth of 8-inch silicon crystals in a double-crucible system are investigated. The numerical results show that a design in which the bottom and the side walls of the crucible are flat lowers the oxygen content, saves energy, and weakens the melt flow turbulence. Moreover, the lowest von Mises thermal stress in the crucible system was obtained with this crucible design. The flat crucible side wall reduces heat loss from the outer melt surface, facilitating heat transfer from the side heater into the melt. The differences in crucible geometry change the temperature distribution and flow pattern in the outer melt but have an insignificant effect on the deflection of the crystal-melt interface.