Czochralski Si crystals were grown by using various V/G ratios (0.23 and 0.38mm2/Cmin), where V was the growth-rate and G was the axial temperature gradient. The axial temperature gradient near to the melt/crystal interface was measured by using a recently developed thermocouple of differential type. Defects in the grown crystals were systematically investigated by multi-chroic infra-red light-scattering tomography to identify experimentally the relationship between the characteristics of defects in the Czochralski Si crystals and the V/G ratios. A high defect density was detected in Czochralski Si crystals grown with a V/G ratio of 0.38mm2/Cmin, in which the density distribution of defects along the crystal growth direction obviously fluctuated. The highest defect density existed in the middle region of the crystal while lower defect density was seen in the top area. No defect was detectable by the multi-chroic infra-red light-scattering tomography system in the Czochralski Si crystal grown under the V/G ratio of 0.23mm2/Cmin. The type of grown-in defects in the Czochralski Si crystal grown under the V/G ratio of 0.38mm2/Cmin was the vacancy agglomeration based on the result of photoluminescence detection and the V/G ratio used for crystal growth.

Relationship between Characteristics of Defects in CZ-Si Crystals and V/G Ratios by Multi-Chroic Infrared Light Scattering Tomography. M.Ma, T.Irisawa, T.Ogawa, X.Huang, T.Taishi, K.Hoshikawa: Journal of Crystal Growth, 234[2-3], 296-304