Grain size, grain uniformity, and (111) texture enhancement by solid-phasecrystallization of F- and C-implanted SiGe films

The crystallization kinetics and film microstructure of poly-SiGe layers ob tained by solid-phase crystallization of unimplanted and C- and F-implanted 100-nm-thick amorphous SiGe films deposited by low-pressure chemical vapor deposition on thermally oxidized Si wafers were studied. After crystalliza tion, the F- and C-implanted SiGe films showed larger grain sizes, both in- plane and perpendicular to the surface of the sample, than the unimplanted SiGe films. Also, the (111) texture was strongly enhanced when compared to the unimplanted SiGe or Si films. The crystallized F-implanted SiGe samples showed the dendrite-shaped grains characteristic of solid-phase crystalliz ed pure Si. The structure of the unimplanted SiGe and C-implanted SiGe samp les consisted of a mixture of grains with well-defined contour and a small number of quasi-dendritic grains. These samples also showed a very low grai n-size dispersion.