High-dose C implantation at between 150 and 250C resulted in the formation of a buried amorphous layer, with a layer of self-organized nanometric amorphous SiCx precipitates and a completely crystalline Si top layer above. It was shown, by Rutherford back-scattering channeling and cross-sectional transmission electron microscopy, that the nature of the defects in the top layer depended critically upon the implantation temperature and determined the annealing behaviour of amorphous SiCx precipitates. At lower implantation temperatures, where extended defects were absent from the top layer, annealing (900C) led to partial crystallization of amorphous SiCx precipitates; accompanied by void formation. The crystallizing SiCx precipitates then acted as sinks for Si self-interstitials. At higher implantation temperatures, dislocations on {111} planes and {311}-defects effectively trapped the self-interstitials and inhibited the crystallization of amorphous SiCx.

Creation of Internal Point Defect Drains in Silicon by Carbon Implantation. M.Häberlen, J.K.N.Lindner, B.Stritzker: Nuclear Instruments and Methods in Physics Research B, 2003, 206, 916-21