密闭式热场下<111>晶向Si单晶高晶转生长研究

在Kayex CG6000单晶炉上采用优化的350 mm密闭式热场,在23~25 r/min高晶转下用直拉法拉制出了Φ76.2~125 mm、n型高阻<111>晶向Si单晶,单晶的外形和径向电阻率均匀性良好。对<111>晶向Si单晶在高晶转下生长容易出现扭曲变形、棱面较宽现象的原因进行了分析。通过添加热屏,加强热场的保温和热屏的隔热作用,及缩小等径生长阶段熔Si液面与热屏间的距离,提高了晶体结晶前沿的温度梯度。从而避免了<111>晶向Si单晶的扭曲变形,减小了单晶棱面宽度,同时有利于消除晶体的漩涡缺陷。

Research on the Growth of <111>-Silicon Crystals with High Seed Rotation in Closed Heat System

The n-type <111>-orientation 76.2-125 mm diameter Czochralski(CZ)silicon single crystals with good shapes and radial resistivity uniformity were grown by 23-25 r/min high seed rotation in optimized closed heat system using Kayex CG6000 furnaces.The reasons for the distortion and wide facet of <111>-silicon single crystals during body growth with high seed rotation were analyzed.Through adding heat shields,strengthening heat insulation of heat shields and the heat system,shortening the distance between Si melt and the heat shield during body growth,the temperature gradient in the crystal along the crystallization front was increased.So,the distortion of <111>-silicon single crystals is avoided,the width of the facet is reduced,and swirl defects of crystals are eliminated easily.