Secondary defects of as-grown oxygen precipitates in nitrogen doped Czochralski single crystal silicon

Abstract

In this work, as-grown defects and their secondary defects in 300 mm nitrogen-doped Czochralski-grown single-crystal silicon (NCZ-Si) are investigated. Secondary defects are revealed by homogeneous epitaxial layer growth, and as-grown defects are decorated via gaseous hydrogen chloride (HCl) etching. Localized light scattering (LLS) technique is utilized to inspect defect distribution and provide the latex sphere equivalent (LSE) size to differentiate defect types. With the locations of LLS, the morphology of defect is observed by scanning electron microscopy (SEM). According to the results, it indicated that secondary defects are extrinsic dislocation loops and stacking fault (SF) loops, which are induced by as-grown oxygen precipitates during the growth and cooling process. Furthermore, the correlation between the counts of secondary defects and nitrogen concentration is obtained. It contributes to the optimization of nitrogen doping to avoid the generation of detrimental defects for device operation.