Regensburg 2004 – wissenschaftliches Programm
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DS: Dünne Schichten
DS 18: Schichtherstellung III
DS 18.2: Vortrag
Donnerstag, 11. März 2004, 17:00–17:15, HS 31
High-Fluence C-Implantation into 3C-SiC: Synthesis of Buried Diamond-Nanocrystals — •Hannes Weishart1, Viton Heera1, Frank Eichhorn1, Bela Pecz2, Lajos Toth2, and Wolfgang Skorupa1 — 1Forschungszentrum Rossendorf, PO Box 510119, D-01314 Dresden — 2Research Institute for Technical Physics and Materials Science, H-1525 Budapest, Hungary
Their outstanding properties, such as wide band gap, high thermal conductivity and saturated electron drift velocity, make silicon carbide and diamond useful semiconductors for applications under harsh conditions. A combination of both materials on a microscopic scale may be a promising way to novel devices.
Ion Beam Synthesis (IBS) is an excellent method for creating precipitates inside any matrix without thermodynamic constraints. We previously demonstrated the synthesis of nanocrystalline 3C-SiC inside diamond by high-fluence Si implantation. In this work we investigate phase formation in carbon-implanted 3C-SiC substrates. Implantations were performed with fluences ranging from 3 × 1017 cm−2 to 3 × 1018 cm−2 . Additionally, the influence of implantation temperature and dose rate was studied using X-ray diffraction (XRD), Raman spectrometry and high-resolution cross-sectional transmission electron microscopy (HRTEM).
Low implantation temperatures and high dose rates favor the formation of graphite precipitates, while in all other cases epitaxial diamond nanocrystals grow. Hence, a critical temperature for diamond formation exists, which depends on dose rate. Increasing the fluence leads to bigger nanocrystals. Diamond platelets of up to 20 nm length were found.