直拉硅中氮在高温退火过程中对氧沉淀的影响

研究了掺氮直拉硅单晶（NCZ）中氮在高温退火过程中对氧沉淀的影响.通过不同温度高温退 火后，测量氧沉淀的生成量和观察硅片体内微缺陷（BMD）密度与高温形核时间的变化关系 ，同时用透射电子显微镜(TEM)观察氧沉淀及相关缺陷的微观结构.实验结果表明高温退火后 氮对硅中氧沉淀形核有明显的促进作用，在相同退火条件下NCZ硅中BMD密度要远远高于相应 的普通直拉硅.这是由于氮在高温下与氧反应形成氮氧复合体（N-V-O）促进了氧沉淀的形核 ，而且TEM的结果表明氧沉淀的形态都是平板状，周围存在应力场. 关键词： 直拉硅 掺氮 氧沉淀

Effect of nitrogen on oxygen precipitation in Czochralski silicon during high-te mperature annealing

The effect of nitrogen on the oxygen precipitation during high-temperature annea ling in Czochralski silicon was investigated. After annealing under different co nditions, the variation of oxygen precipitation and the bulk microdefects(BMDs) density with annealing time at high temperatures was measured, and transmission electronic microscope was used to observe the microstructure of oxygen precipita tes. It was found that nitrogen doping strongly enhanced oxygen precipitation du ring high-temperature annealing; furthermore, the densities of BMDs in the annea led NCZ samples were higher than those in the corresponding CZ ones. Therefore, it is considered that the nitrogen can react with vacancy and oxygen to form N-V -O complexes to enhance the nucleation of oxygen precipitates, and the oxygen pr ecipitates are plates with strong inner stress.