Light-scattering tomography, a powerful method for the rapid and non-destructive observation of structural defects in semiconductor monocrystals, was applied - for the first time - to the investigation of the defect distribution of 6H-SiC monocrystalline wafers. In conventional light-scattering tomography observation, a difference in tomograms between N-doped and semi-insulating 6H-SiC wafers was found. It was caused by the difference in optical absorption and scattered light in wafers. Three-dimensional light-scattering tomographic images of the defects were successfully constructed by rendering layer-by-layer 2-dimensional light-scattering tomographic images on various planes perpendicular to the direction of crystal growth. The 3-dimensional light-scattering tomographic images showed clearly the various defect distributions in depth direction.

Defect Distribution in N-Doped and Semi-Insulating 6H-SiC Bulk Single Crystal Wafers Observed by Two- and Three-Dimensional Light Scattering Tomography. P.Wutimakun, T.Mori, H.Miyazaki, Y.Okamoto, J.Morimoto, T.Hayashi, H.Shiomi: Japan Journal of Applied Physics, 2008, 47, 5576-80