快速退火对大直径CZSi单晶中原生微缺陷的影响

Efifect of RTA on Grown-in Defects in Large-diameter CZSi

本文利用快速退火对φ8″直拉硅单晶片中的流动图形缺陷(FPDs)进行了研究。首先用Secco腐蚀液腐蚀了大直径直拉硅片,利用光学显微镜观察了FPDs的宏观分布,并用原子力显微镜(AFM)对原生FPDs的微观形貌进行观察,证明了FPDs是一种空位型原生缺陷,然后采用了高温快速热处理,分别在N2、N2／O2(3％)、Ar三种气氛中对原生直拉单晶硅片进行了处理。对比退火前后FPDs密度的变化,分析了高温快速热处理对直拉硅单晶片中FPDs的影响,实验表明1200℃快速热处理180s可以显著降低硅片表面的FPDs。

Flow pattern defects (FPDs) in φ8 double prime CZSi wafers were investigated through rapid thermal annealing (RTA). The wafers were etched in Secco etchant and observed by the. optical microscopy. The results show that FPDs are vacancy-type grown-in defects. The annealing process was performed in RTA instrument, the atmospheres were N2, N2/O2 and Ar respectively. Compared with the changes of the FPDs density before and after annealing, the influence of RTA was discussed. The results prove that the density of FPDs can be reduced subsequently after RTA at 1200°C with 180 s.