Epitaxial growth of silicon on silicon implanted with iron ions and optical properties of resulting structures

The method of ultrahigh-vacuum low-temperature ($T$ = 850$^\circ$C) purification of silicon single crystals having the (100) and (111) orientation and implanted with low-energy ($E$ = 40 keV) iron ions with various doses ($\Phi$ = 1 $\cdot$ 10$^{15}$–1.8 $\times$ 10$^{17}$ cm$^{-2}$) and subjected to pulsed ion treatment (PIT) in a silicon atom flow has been tested successfully. The formation of semiconducting iron disilicide ($\beta$-FeSi$_2$) near the surface after PIT is confirmed for a Si(100) sample implanted with the highest dose of iron ions. The possibility of obtaining atomically smooth and reconstructed silicon surfaces is demonstrated. Smooth epitaxial silicon films with a roughness on the order of 1 nm and a thickness of up to 1.7 $\mu$m are grown on samples with an implantation dose of up to 10$^{16}$ cm$^{-2}$. Optical properties of the samples before and after the growth of silicon layers are studied; the results indicate high quality of the grown layers and the absence of iron disilicide on their surface.