10cm VGF法GaAs单晶生长过程中热应力的数值模拟  

Numerical simulation technology studing thermal stress in the 10 cm VGF-GaAs single crystal growth

作　　者：涂凡[1] 苏小平[1] 屠海令[1] 张峰燚[1] 丁国强[1] 王思爱[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：《红外与激光工程》2010年第3期411-413,426,共4页Infrared and Laser Engineering

基　　金：国家863计划资助项目(2002AAF3102)

摘　　要：采用数值模拟技术模拟了10cm(4in)VGF法GaAs单晶生长过程中的温场分布、固液界面形貌以及热应力分布。推导得到了固液界面形状与轴向温度梯度和径向温度梯度之间的关系,定义了一个固液界面形状函数,用以表征固液界面偏离度。固液界面偏离度可定义为晶体边缘和晶体中心轴向位置的差值。计算得到固液界面凹(凸)度的临界值,小于该值时,固液界面附近的热应力低于临界分解剪切应力(CRSS)。模拟计算了两个时刻的晶体中的热应力分布:当偏离度大于临界值时,晶体中的热应力大于CRSS,反之,晶体中的热应力小于CRSS,验证了理论推导的结果。The numerical simulation was employed to study the temperature field distribution, solid-liquid interface shape and the thermal stress distribution in the 10 cm single crystal growth process using VGF method. The relationship among solid-liquid interface shape with the axial temperature gradient and the radial one were derived. Function of solid-liquid interface shape was defined to characterize the deviation of the solid-liquid interface. The difference value between the center and the edge of the crystal along the axial direction could be defined as the deviation of the interface. The maximum allowable deviation of the interface was calculated. When the deviation was smaller than the maximum one, the crystal closed to the growth interface would sustain a thermal stress which was smaller than the critical resolved shear stress. The thermal stress distribution was calculated in two different time. It was found that the crystal thermal stress was larger than the critical resolved shear stress when the deviation was bigger than the critical one and vice versa. This phenomenon verifis the theoretical derived result.

关 键 词：数值模拟 VGF GAAS 固液界面 热应力 临界剪切应力 

分 类 号：TN304.2[电子电信—物理电子学]