The relationship between flow-pattern defects, Secco etch-pit defects, defects detected by infra-red light-scattering tomography, and defects detected by optical precipitate profiling, was investigated within the same areas of as-grown and annealed wafers. It was concluded that the relationship between grown-in defects in as-grown Czochralski crystals could be expressed as: [light-scattering tomography defects] = [optical precipitate profiling defects] = [flow-pattern defects] + [Secco etch-pit defects]. The flow-pattern defects decreased during annealing, but light-scattering tomography defects were still observed at positions where they were detected in the as-grown state. It was found that the nuclei of flow-pattern defects were not annihilated by annealing.

S.Umeno, M.OKui, M.Hourai, M.Sano, H.Tsuya: Japanese Journal of Applied Physics - 2, 1997, 36[5B], L591-4