The strain and damage produced on Si substrates by high-dose ion
implantation of Si and C is investigated after thermal treatments by double
and triple crystal X-ray diffraction, high ressolution transmission electron
microscopy (HRTEM) and Secondary Ion Mass Spectrometry (SIMS). Si
implantation (180 keV, 5×1015 Si at cm−2) at liquid
nitrogen temperature forms a buried amorphous layer. Annealing at
temperatures close to 650°C results in epitaxial films with significant
defect recovery. X-ray rocking curves show the existence of interference
fringes on the left hand side of the 004 Si peak indicating the presence of
tensile strained Si layers due to the generation of Si interstitials during
the implantation process. C implantation, at 60 keV, 7×1015
cm−2 and 450°C, in the preamorphized Si wafers results in the
growth of Si1-yCy epitaxial films with a low amount of
substitutional carbon (y≍ 0.1%). Rapid thermal annealing at 750°C results in
highly defective epitaxial films with a maximum carbon content close to
0.4%.The high density of defects is responsible for the partial strain
relaxation observed in those layers. The amount of substitutional Si also
decreases drastically with increasing temperature. Profile fitting of
rocking curves using dynamical X-ray theory is used to estimate the C
concentration and the strain and disorder profiles of the
heterostructures.