Structural characterization of dual ion implantation in silicon

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Beam interactions with materials and atoms, 2015-12, Vol.365, p.39-43
• Main Authors: Nunes, B., Franco, N., Botelho do Rego, A.M., Alves, E., Colaço, R.
• Format: Article
• Language: English
• Subjects: Annealing; C+ implantation; Dual ion-implantation; Fe+ implantation; Phases; Scanning electron microscopy; Silicides; Silicon; Silicon carbide; Ti+ implantation; X-ray photoelectron spectroscopy; X-rays
• ISSN: 0168-583X; 1872-9584
• DOI: 10.1016/j.nimb.2015.08.006

〈100〉 Si wafers were dual implanted at room temperature with Fe+C and Ti+C with fluences of 2×1017cm−2. The samples were annealed in vacuum at 800°C and 1000°C respectively, and characterized in scanning electron microscope (FEG-SEM), grazing incidence X-ray diffraction (GIXRD) and X-ray photoelectron spectroscopy (XPS). The scanning electron microscopy characterization showed that both annealings generated precipitates, with sizes within the range of 10–100nm at 800°C and 1–10μm for the 1000°C annealing. The GIXRD measurements revealed the presence of different silicides phases. For the Fe+C implantation β-FeSi2 was observed at 800°C while at 1000°C α-FeSi2 and SiC were found. The Ti+C sample at 800°C showed simultaneously the presence of four different phases, both metastable C49 and stable C54 silicide TiSi2, poly-Si and SiC. At higher temperatures the metastable C49-TiSi2 silicide phase was no longer observed, all the others remaining. The XPS analysis confirmed the existence of the SiC at 1000°C temperature, and showed that the initial carbon clusters get richer in Si with the increase of temperature to form SiC. It was also possible to see that among all present species, C was the one that oxidized the most with increasing temperature.