中文摘要：

在多晶硅铸锭炉内采用了凹坑坩埚和凹坑坩埚平台组合的改进结构，并结合COMSOL4．3a模拟软件对改进前后的热场做了对比分析。结果表明：与改进前相比，在改进后的热场结构中，硅熔体结晶界面趋于平坦，等温线更加均匀，熔体轴向温度梯度增加了大约2K／cm，有利于柱状晶的生长；硅熔体对流强度增大，可以使溶质分布更加均匀；CdVs变大、溶质边界层厚度减小，有利于阻碍结晶界面前沿发生组分过冷，进一步抑制结晶界面细晶的产生。

英文摘要：

The optimization of thermal structure uses the multi-crystalline casting furnace with notched crucible and pit crucible pedestal, then the thermal distribution combining the simulation soft-ware with comsol4.3a before and after optimization were analyzed. The stimulation results indicate that： after optimization, the interface of silicon melt becomes flatten and the isothermal become uniform as well as the axial temperature gradient in silicon melt increasing about 2 k/cm, which is conducive to the growth of columnar crystals in multi-crystalline silicon. The convection intensity in the silion melt becomes strengthen, so the solute distributes more uniform. It is difficult to generate constitutional supercooling in the crystalline intreface since the Gt/Vs becoming large and the solute boundary layer thickness decreasing, which can suppress the geuneration of fine grain.