Spatial variations in the crystallinity of recrystallized samples, which had been ion-implanted and then flash-lamp annealed, were studied by means of Raman imaging. Clusters which were a few microns in size, and which contained a high density of defects, were created in samples that had been annealed at temperatures above 700C. A Raman band of this cluster region was broad and shifted to the low-frequency side of the crystalline Si band (520.5/cm). The peak frequency and width of the broad Raman band which was characteristic of the clusters changed with position in the clusters. In samples which were annealed at 700C, the peak frequency and width of the broad band were almost constant for various wavelengths of the exciting laser. This indicated that the spatial variation of the defect density in the cluster was small for samples that were annealed at low temperatures. In samples which were annealed at 1000C, the peak frequency of the broad band shifted to the low-frequency side and the bandwidth increased as the wavelength of the exciting laser became longer. This wavelength dependence indicated that the defect density within the clusters was distributed inhomogeneously through the depth, and decreased in the region close to the free surface.

K.Mizoguchi, S.Nakashima, H.Harima, T.Hara: Materials Science Forum, 1995, 196-201, 1547-52