Reduction of polycrystalline grains region near the crucible wall during seeded growth of monocrystalline silicon in a unidirectional solidification furnace

摘要

The generation of polycrystalline grains region near the crucible wall during seeded growth of monocrystalline silicon in a unidirectional solidification furnace was analyzed numerically. The crystal-melt interface is tracked by an enthalpy method. Numerical results show that some polycrystalline silicon grains generates along the crucible wall and marches into the interior of crystal. The ratio of polycrystalline silicon grains in a global crystal is mainly determined by a ratio of thermal flux along the crucible wall to thermal flux along the seed. By reducing the thermal flux along the crucible wall or by increasing the thermal flux along the seed, the ratio of polycrystalline silicon grains in a global crystal can be markedly reduced.