摘要
为了制备纯度11N以上、直径φ大于45mm并且各项性能指标满足探测器级要求的大直径超高纯单晶Si材料，本文在真空气氛下提纯并生长垂52～65mm探测器级区熔（FZ，float zone）Si单晶，并对真空气氛和直径增加所带来的晶体不稳定生长、高断面电阻率不均匀率和漩涡缺陷等问题的产生原因和解决方式进行了深入研究。结果表明，丹麦加热线圈表面带有台阶和十字开口，是提纯和生长φ大于45mm多晶Si和单晶Si的理想线圈；适当提高单晶转速和生长速度有利于降低断面电阻率不均匀率，且提高转速的效果更加明显；真空气氛下，提高热场对中性可抑制漩涡缺陷的产生，其对漩涡缺陷的影响比单晶Si生长速度更加显著，这是与Ar气气氛FZ不同的；多晶Si提纯次数越多单晶Si寿命越低，降低多晶Si原料中的P／B和重金属原始含量有利于提高单晶2Si寿命；若要制备少子寿命大于800μs，符合探测器级标准的φ52～65mm Si单晶，多晶Si原料少子寿命应大于3000μs。
In order to prepare ultra-high purity silicon material whose purity is larger than 11 N, diameter is larger than 45 mm and all performance indices could meet the detector level requirements,the φ（52- 65） mm detector level silicon crystal was prepared by vacuum floor zone （FZ） technology. The cause and solution of unstable growth problem, tow radial resistivity uniformity and swirl defect problems caused by vacuum atmosphere and the increasing of crystal diameter are analyzed. The results indicate that Denmark coil with cross slits and steps on its surface is the ideal one for growing φ〉45 mm crystals. Increasing the growth and rotation speeds of the mono-crystal is good for decreasing the radial resistivity uniformity,and increasing the rotation speed is the better option. Increasing the concentricity of thermal field is good for reducing the swirl defect,its influence on swirl is more remarkable than crystal growth speed, and it is different from Ar atmosphere FZ technology. With the increasing of the refinement times of poly-crystal, the lifetime of mono-crystal will decrease. The low original concentrations of P, B and metal in poly-erystal are good for enhancing the lifetime of mono-crystal. To prepare φ（52-65） mm detector level mono-crystal whose lifetime is longer than 800μs, the poly-crystal silicon lifetime should be longer then 3 000μs.
出处
《光电子．激光》
EI
CAS
CSCD
北大核心
2013年第12期2301-2307,共7页
Journal of Optoelectronics·Laser
基金
科研院所技术开发研究专项基金(2010EG115068
2012EG115014)资助项目
