旋转工艺对高阻区熔硅单晶研制的影响

Effect of the Rotating Process on the Preparation of the High Resistivity FZ-Si Single Crystals

采用区熔工艺对多次真空提纯后的多晶硅进行了n型高阻硅单晶生长。真空提纯时,通过对工艺参数的精确控制,稳步提升了晶体的纯度和电阻率。单晶生长时,对比分析了常规旋转工艺和正反转旋转工艺两种生长方式对单晶径向电阻率分布的影响,并通过计算得到了杂质在单晶径向上的分布规律。分析认为正反转旋转工艺可以精确地控制杂质在单晶径向上的分布情况,进而确保了单晶径向上的磷杂质含量略大于硼杂质含量。最终,通过采用正反转旋转工艺,成功研制了电阻率为8 000Ω·cm以上的n型高均匀性区熔硅单晶。

Vacuum float zone（FZ）refining process was used in the repeated polysilicon purification,and then the n-type silicon single crystal with high resistivity was grown.Through the precise control of the process parameters,the purity and resistivity of the crystal were improved steadily during the vacuum purification.During the single crystal growth,the influences of two growth modes of the normal rotating process and positive and negative rotating process on the single crystal radial resistivity distribution were compared and analyzed,and then the single crystal radial distribution of the impurities was calculated.The analysis shows that the single crystal radial distribution of impurities can be precisely controlled through the positive and negative rotating process,ensuring that in the single crystal radial direction,the content of the phosphorus impurity is slightly larger than that of the boron impurity.Finally,through the positive and negative rotating process,the n-type high uniformity FZ-Si single crystal with8 000Ω·cm resistivity was developed successfully.