悬浮区熔法中线圈中心厚度对电磁场的影响

Influence of the Coil Center Thickness on the Electromagnetic Field in the Floating Zone Method

为提高悬浮区熔(FZ)法的成晶率,使用模拟计算软件深入研究FZ硅单晶的生长过程。本文通过Comsol Multiphysics软件模拟FZ炉内的电磁场,分析不同线圈中心厚度对于电磁场的影响。随着线圈中心厚度增加,熔化的多晶硅表面电磁能量减小,而熔体自由表面电磁能量增加。如果线圈中心厚度过小,较小熔体自由表面电磁能量会导致穿过线圈的多晶硅棒中心区域不熔化;如果线圈中心厚度过大,较小熔化的多晶硅表面电磁能量使熔化的多晶硅减少,引起熔体自由表面形状改变。之后,本文使用中心厚度为1 mm、1.5 mm和2 mm线圈生长6英寸硅单晶,发现线圈中心厚度为1.5 mm时,线圈产生的电磁场更有利于硅单晶生长。

In order to improve the crystal formation rate of the floating zone(FZ)method,the growth process of FZ silicon single crystal was studied by simulation software.The electromagnetic field in the FZ furnace was simulated by Comsol Multiphysics software,and the influence of the coil center thickness on the electromagnetic field was analyzed.With the coil center thickness increases,the electromagnetic energy on the melted polysilicon surface decreases,but the electromagnetic energy on the free surface of the melt increases.If the coil center thickness is too small,the center of the poly rod passing through the coil will not melt due to the small electromagnetic energy on the free surface of the melt.If the coil center thickness is too large,the small electromagnetic energy on the melted polysilicon surface will make the poly melt slowly,causing the changing of the free surface shape of the melt.Then,the 6 inch crystals were grew by the coils and the coil center thicknesses are 1 mm、1.5 mm、2 mm,respectively.It is found that the electromagnetic field generated by the coil is beneficial to the growth of the silicon single crystal when the coil center thickness is 1.5 mm.