摘要
在CZ法生长太阳能级单晶硅中,单晶炉的导流筒、热屏和炭毡对晶体生长有很大影响。通过对上述三个部件进行改进优化,并通过数值模拟对优化前后晶体和熔体的热场、热屏外表面与石英坩埚内壁面之间的氩气流场以及晶体中的热应力进行分析,得出以下结论:石墨导流筒的引入减少了炉体上部的氩气流动涡胞,进而减少了S iO在单晶炉上部的沉积;优化后的热屏减少了加热器对晶体的烘烤,使结晶速率加快;优化后的侧壁炭毡阻止了加热器向上部的热损失。优化后在加热器功耗不变时,结晶速率至少可提高35%,而不增加宏观位错的发生概率。
In solar-grade single crystal growth with CZ method,the geometries of flow guide,radiation shield and side wall insulation are main parameters affecting the heat fields and crystal growth.By changing the above parameters,an optimization of the heat fields was attempted.Numerical simulations of the thermal fields before and after optimization were conducted.Through analysis of the temperature distribution in the crystal and melt,the argon gas flow between radiation shield and quartz crucible,and the thermal stress in the crystal,it was found that the optimized flow guide can decrease the SiO deposition on the upper wall;the optimized radiation shield can reduce the baking of crystal by the heater;and the optimized side insulation can prevent the heat loss upward.In general,after optimization,under the same heater power,the crystallization rate increases over 35%,without increase of macro-dislocation probability.
出处
《人工晶体学报》
EI
CAS
CSCD
北大核心
2010年第2期524-528,544,共6页
Journal of Synthetic Crystals
基金
江苏省普通高校研究生科研创新计划资助项目(No.1291130015)
关键词
单晶硅
数值模拟
热屏
炭毡
Si single crystal
numerical simulation
radiation shield
carbon felt
