Damage accumulation in $Si$ during high-dose self-ion implantation

Accumulation and annealing of damage in $Si$ implanted with self-ions to high doses were investigated using a combination of grazing incidence diffuse x-ray scattering, high-resolution x-ray diffraction scans, and transmission electron microscopy. During implantation at $100°C$⁠, small vacancy and interstitial clusters formed at low doses, but their concentrations saturated after a dose of $≈3×1014cm−2$⁠. The concentration of Frenkel defects at this stage of the implantation was $≈1×10−3$⁠. At doses above $1×1015cm−2$⁠, the concentration of implanted interstitial atoms began to exceed the Frenkel pair concentration, causing the interstitial clusters to grow, and by $≈3×1015cm−2$⁠, these clusters formed dislocation loops. Kinematical analysis of the rocking curves illustrated that at doses above $1×1015cm−2$ the “plus one” model was well obeyed, with one interstitial atom being added to the dislocation loops for every implanted $Si$ atom. Measurements of Huang scattering during isochronal annealing showed that annealing was substantial below $700°C$ for the specimens irradiated to lower doses, but that little annealing occurred in the other samples owing to the large imbalance between interstitial and vacancy defects. Between 700 and $900°C$ a large increase in the size of the interstitial clusters was observed, particularly in the low-dose samples. Above $900°C$⁠, the interstitial clusters annealed.