Abstract:
The effect of pulsed ion-beam annealing on the surface morphology, structure, and composition of single-crystal Si(111) wafers implanted by chromium ions with a dose varying from 6 $\times$ 10$^{15}$ to 6 $\times$ 10$^{16}$ cm$^{-2}$ and on subsequent growth of silicon is investigated for the first time. It is found that pulsed ion-beam annealing causes chromium atom redistribution in the surface layer of the silicon and precipitation of the polycrystalline chromium disilicide (CrSi$_2$) phase. It is shown that the ultrahigh-vacuum cleaning of the silicon wafers at 850$^\circ$C upon implantation and pulsed ion-beam annealing provides an atomically clean surface with a developed relief. The growth of silicon by molecular beam epitaxy generates oriented 3D silicon islands, which coalesce at a layer thickness of 100 nm and an implantation dose of 10$^{16}$ cm$^{-2}$. At higher implantation doses, the silicon layer grows polycrystalline. As follows from Raman scattering data and optical reflectance spectroscopy data, semiconducting CrSi$_2$ precipitates arise inside the silicon substrate, which diffuse toward its surface during growth.
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