Crystalline-to-amorphous transition for Si-ion irradiation of Si(100)

Silicon (100) crystals are implanted with 1-MeV Si2+ ions to a fixed fluence of 1×1015 ions/cm2 at systematically different incident-ion dose rates, R, and substrate temperatures, T. A critical dependence on T is found for Rt, the critical flux for formation of a continuous amorphous layer in the substrate material. The activation energy characterizing the process is found to be 0.9 0.05 eV, which is attributed to the collapse of defect complexes formed during irradiation. Critical temperatures for this process, at each fixed dose rate, are all near room temperature.