多晶硅定向凝固铸锭炉热场改进数值模拟研究

Abstract

多晶硅定向凝固铸锭炉的热场对于生长高质量的多晶硅极为重要。本文利用CGSim软件对多晶硅铸锭炉热场的底部边缘、侧边增加保温材料的改进并进行了数值模拟研究，与未改进的热场进行了对比，分析了这些改进对温场、流场和固液生长界面的影响。模拟结果表明，热场改进后，等温线在坩埚底部边缘和侧边部位变得平缓，抑制了坩埚底部边缘的散热以及边缘横向晶的产生，熔体流动更加有利于杂质排出，多晶硅的定向凝固生长质量得到了提高。The hot zone of the directional solidification multi-crystalline silicon furnace is extremely important to the quality of multi-crystalline silicon. In this paper, numerical simulation was carried out by using CGSim on the added heat preservation structures in the bottom edges and sidewalls of the hot zone and its effects on the temperature field, flow field and interface were analyzed. Simulation results show that, after the optimization of the hot zone, isotherms around the bottom edges and the sidewalls become flat and the flow of the molten silicon is better to remove the impurities. Therefore, the quality of the multi-crystalline silicon by directional solidification is improved.