Relationship between grown-in defects in Czochralski silicon crystals

The relationship between flow pattern defects (FPDs), Secco etch pit defects (SEPDs), defects detected by IR light scattering tomography (LSTDs) and defects detected by an optical precipitate profiler (OPP-defects) was investigated in the same area of as-grown and annealed wafers. It was concluded that the relationship between grown-in defects in as-grown Czochralski silicon crystals is expressed as LSTDs=OPP-defects=FPDs+SEPDs. FPDs were decreased after annealing, but LSTDs were still observed at the positions where the LSTDs were detected in the as-grown state. It was found that the origins of FPDs are not annihilated during annealing.