Low-temperature epitaxial growth of cubic SiC thin films on Si(111) using supersonic molecular jet of single source precursors

Epitaxial cubic SIC thin films have been deposited on Si(111) by supersonic molecular jet epitaxy of the single source precursors of methylsilane (MS) , CH3SiH3, and dimethylethylsilane (DMES), (CH3)(2)SiH(CH2CH3), at temperat ures in the range 780-950 degrees C. Single crystalline, crack-free epitaxi al cubic SiC thin films were successfully grown on carbonized Si(111) subst rates at temperatures as low as 830 degrees C using MS and DMES. Highly ori ented cubic SiC thin films in the (111) direction were obtained on uncarbon ized Si(111) substrates at 780 degrees C using MS and at 950 degrees C from DMES. However, the growth temperature of DMES was lowered to 830 degrees C on Si(111) when the substrates were initially carbonized with a supersonic jet of acetylene. Below 780 degrees C, moreover, only polycrystalline cubi c SiC thin films were grown on either carbonized or uncarbonized Si(111) su rfaces with MS. The advantage of supersonic molecular jets of the single so urce precursors employed in this study is evident in that the surface carbo nization process may not be necessary, and the deposition procedure is quit e simple and safe to handle. Real-time, in situ optical reflectivity was us ed to monitor the film growth. The as-grown films were characterized in sit u by Auger electron spectroscopy (AES) and ex situ by ellipsometry, SEM, FT IR, UV/Visible spectroscopy, and XRD (especially omega and phiscan measurem ents). (C) 1999 Elsevier Science S.A. All rights reserved.