热屏和后继加热器对生长φ300mm硅单晶热场影响的数值分析

Numerical Analysis of the Effects of Heat Shield and Successor Heater on Heat Field of φ300mm Si Single Crystal

本文采用有限体积元法软件CrysVUn对直拉法生长直径300mm硅单晶热场和热应力分布进行了模拟。后继加热器通过补充晶体径向的热散失,使得沿生长界面径向的由熔体向晶体的热输运实现平衡,使晶体生长界面更加平坦。随着热屏材料热辐射率的降低,晶体生长界面趋于平坦,生长界面上方热应力水平也随着热屏材料辐射率的减小而下降,使用内层高辐射率材料、外层低辐射率材料的复合式热屏结构进一步降低了晶体生长界面中心高度。

A finite volume software CrysVUn was used for the simulation of heat field and stress distribution of 300mm Si crystal.The successor heater can be used to supply the radial heat dissipation,and the melt to crystal heat flow is balanced by this process,so that the crystal growth interface became more flatted.Thermal stress in the crystal upon the growth interface decreases when the emissivity of heat shield material decreases.The thermal shield with high emissivity material inside and low emissivity material outside can greatly lower the interface height in the center of the crystal.