Internal mechanical strains were investigated, using double-crystal X-ray diffractometry, in (100) bulk material which had been implanted with 150keV Ge+ ions to a dose of 2 x 1015/cm2 and co-implanted with 65keV C+ ions to doses ranging from 3 x 1013 to 1016/cm2. The re-grown implanted layers were studied by using plan-view and cross-sectional transmission electron microscopy. The results showed that there was a source of strain, at the depth of the end-of-range damage, in implanted and annealed crystals. The presence of C atoms in this region reduced the mechanical strain and avoided the formation of extended defects. This effect was attributed to the trapping of Si interstitials by C atoms. It was suggested that strain compensation could also prevent the formation of extended defects in the end-of-range region.

J.Suprun-Belevich, F.Cristiano, A.Nejim, P.L.F.Hemment, B.J.Sealy: Semiconductor Science and Technology, 1998, 13[2], 220-5