DEPOSITION OF EPITAXIALLY ORIENTED FILMS OF CUBIC SILICON-CARBIDE ON SILICON BY LASER-ABLATION - MICROSTRUCTURE OF THE SILICON-SILICON-CARBIDE INTERFACE

Excimer laser ablation has been used to deposit epitaxial films of β-SiC on single-crystal Si wafers, in a vacuum, at substrate temperatures between 1050 and 1250 °C. Such films can be grown by ablating ceramic SiC, carbon, or alternating silicon and carbon targets at a range of growth rates. X-ray θ-2θ diffraction shows the presence of strong, sharp reflections from crystal planes parallel to the substrate, 200 and 400 for [100] substrates and 111 and 222 for [111] oriented substrates. Wrong reflections, such as 111 for [100] substrates, are extremely weak or absent, indicating alignment with the substrates. The characterization of these films by a number of techniques is discussed. In all cases the film-substrate interface shows a characteristic microstructure of cavities in the Si substrate, similar to that observed for the carbonization layer initially formed as a precursor for chemical-vapor deposition of SiC films on Si. This implies that the initial film growth, for all cases, involves chemical reaction of the Si substrate with the carbon in the plume as well as transport through the growing film. © 1995 American Institute of Physics.