Study of inhomogeneous radial distribution of defects in As-grown and annealed Czochralski silicon crystals by multi-chroic infrared light scatteringtomography

Multi-chroic infrared light scattering tomography (MC-IR-LST) and transmiss ion electron microscopy (TEM) were used to systematically investigate the i nhomogeneous radial distribution of defects in as-grown and annealed Czochr alski silicon (CZ-Si) crystals. A new defect morphology of dark stripes obs erved for the first time by the MC-IR-LST system in a special region in the as-grown CZ-Si crystal. After annealing the crystal at 1150 degreesC for 1 6 h in an O-2 atmosphere, dark stripes that became scattered in width and d eep in contrast were clearly visible in an OSF-ring area. The location of t hese stripes in the as-grown crystal coincided with that in the annealed CZ -Si crystal, where many stacking faults and oxygen-precipitate-related poly hedral defects were revealed by TEM analysis. This means that the dark stri pes were generated during crystal growth as original grown-in defects. Quan titative measurement of the inhomogeneous radial distribution of defects in the annealed crystal was made and the characteristics of the defects in di fferent regions of the crystal were analytically discussed.