Raman characterization of hydrogen ion implanted silicon: “High-dose effect”?

The Raman spectra of nanostructures formed on silicon Si single-crystalline wafers by implantation with hydrogen ions of fluencies ranging within D∼2×1016–3×1017 cm−2 are reported. The presence of both crystalline and amorphous silicon phases were found in the spectra. A non-monotonic growth in the intensities of the peaks originating from the crystalline and the amorphous phases with a dose of the implantation was registered. A ratio of the intensities of the main peaks of the amorphous to the crystalline Si phases also demonstrated a non-monotonic behaviour (“high-dose effect”). Possible reasons and mechanisms of the non-monotonic dependence of a “degree” of amorphization on a dose of the implantation (or irradiation) are discussed.