6英寸砷化镓单晶VGF法生长中坩埚-埚托间隙对晶体生长过程影响  

Optimization of Gap between Crucible and Support during Growth of 6 Inch VGF GaAs Single Crystal by Numerical Simulation

作　　者：涂凡[1] 苏小平[1] 张峰燚[1] 黎建明[1] 丁国强[1] 

机构地区：[1]北京有色金属研究总院,北京国晶辉红外光学科技公司,北京100088

出　　处：《稀有金属》2011年第4期617-622,共6页Chinese Journal of Rare Metals

基　　金：国家863项目(2002AAF3102)资助

摘　　要：在VGF法生长6英寸GaAs单晶的实际生长过程中,坩埚与坩埚托之间难以实现完全的理想贴合。坩埚与埚托之间的空隙对晶体生长过程中的温场和固液界面形状影响较大。通过模拟计算5种不同的空隙形状时的温场与热应力分布,发现随着空隙面积的增大,固液界面在轴向上的位置逐渐下降。在锥形空隙情况下,得到一个平坦的固液界面。设计了两种不同的空隙填充方案,模拟计算的结果表明,液态Ga完全填充时,在晶体轴向上热应力的分布较为平缓,有利于生长低位错、高质量的GaAs单晶。There was a gap between the crucible and the support in the process of 6 inch GaAs single crystal grown by VGF（Vertical Gradient Freeze） technique,which had great effect on the solid-liquid interface shape and the thermal field.With the aid of the numerical simulation,it could be found that when the gap′s area was bigger,the interface′s position in the axial direction was lower.A plant interface was achieved when there was a cone gap.Two different solutions about the gap stuffs to optimize the temperature field were carried out.The numerical simulation results showed that there was a smooth thermal stress distribution curve along the axial direction when the gap was stuffed by Ga.In this situation,a high quality GaAs single crystal with low dislocation density could be achieved.

关 键 词：垂直梯度凝固 数值模拟 空隙 固液界面 热应力分布 

分 类 号：O472[理学—半导体物理]