热屏优化对大直径单晶硅生长影响的数值模拟  

Numerical Simulation on Effect of Heat-shield Optimization on the Growth of Large-Diameter Silicon Single Crystal

作　　者：滕冉[1,2] 戴小林 徐文婷[1,2] 肖清华 周旗钢[1,2] 

机构地区：[1]北京有色金属研究总院,北京100088 [2]有研半导体材料股份有限公司,北京100088

出　　处：《人工晶体学报》2012年第1期238-242,252,共6页Journal of Synthetic Crystals

基　　金：科技部国际科技合作项目(2007DFC50310);国家科技重大专项项目(2008ZX02401)

摘　　要：通过对28英寸热场生长300 mm硅单晶过程中结晶速率、固液界面形状、晶体中热应力及晶体中氧含量的数值计算提出了在该热场条件下热屏的优化方案。数值计算结果表明:对热屏底端与晶体表面和熔体自由液面的距离以及热屏材料(优化前热屏使用单一石墨材料,优化后采用辐射率较高的内壁材料结合反射率较高的外壁材料组成复合式热屏)的优化可以减少主加热器对晶体的热辐射使得固液界面更加平坦,藉此增加结晶速率,减小晶体内热应力和熔体中氧含量。Based on analysis of the rate of crystallization,the shape of melt/crystal interface,thermal stress in crystal,oxygen content in melt,we give an optimized scheme in heatshield including the position and the materials of the heatshield.This simulation not only depended on the global thermal environment of the crystal and the melt,but also depended on the turbulent melt convection.Research on thermal gradient,von Mises stress distribution,rate of crystallization and oxygen content revealed that the optimized heat-shield can reduce the thermal radiation of crystal by the heater,increase the rate of crystallization,flat the melt/crystal interface,reduce the Von Mises Stress,increase the flow rate of argon and decrease the oxygen content.

关 键 词：硅单晶 数值模拟 热屏 固液界面 

分 类 号：O78[理学—晶体学]