线圈台阶数量对悬浮区熔炉内电磁场和热场的影响

Influences of the Number of Coil Steps on Electromagnetic and Thermal Fields in Floating Zone Furnace

为了提高悬浮区熔(FZ)法的成晶率和增加FZ法生长硅单晶的直径,使用模拟计算软件对FZ硅单晶生长过程进行了深入研究。通过Comsol Multiphysics软件模拟了FZ炉内的电磁场和热场,分析了加热线圈台阶数量对电磁场和热场的影响。随着加热线圈台阶数量的增加,台阶处磁场强度降低,熔化的多晶硅表面远离中心位置附近的电磁能量和面电流密度增加,在主狭缝前缝尖端和后缝末端正下方的自由熔化表面的电磁能量、面电流密度和温度降低。因此,加热线圈台阶数量的增加可以使多晶硅表面熔化更加均匀并有效抑制液态硅从主狭缝下方边缘处溢出,提高FZ硅单晶生长的稳定性。

To increase the crystal formation rate and the diameter of the silicon single crystal grown by the floating zone(FZ)method,the growth process of FZ silicon single crystals was investigated deeply with the simulation calculation software.The electromagnetic field and thermal field in the FZ furnace were simulated by Comsol Multiphysics software,and the influences of the number of heating coil steps on the electromagnetic field and thermal field were analyzed.As the number of heating coil steps increases,the magnetic field strength at the steps decreases,the electromagnetic energy and surface current density at the melting polycrystalline silicon surface away from the center position increase,and the electromagnetic energy,surface current density and temperature of the free melting surface below the tip of the front main slit and the end of the rear main slit decrease.Therefore,the increase of the number of heating coil steps can make the surface of polycrystalline silicon melt uniformly and effectively suppress the overflow of liquid silicon below the main slit from the edge,improving the stability of the growth of FZ silicon single crystals.