Deposition of nanocrystalline cubic silicon carbide films using the hot-filament chemical-vapor-deposition method

Nanocrystalline cubic silicon carbide (3C-SiC) films embedded in an amorpho us SiC matrix were fabricated by the hot-filament chemical-vapor-deposition technique using methane and silane as reactance gases. High-resolution tra nsmission electron micrographs clearly showed that these films contain naon crystallites, with an average dimension of about 7 nm, embedded within an a morphous matrix. X-ray photoelectron spectroscopy, x-ray diffraction, infra red absorption, and Raman scattering studies revealed the nanocrystallites as having the structure of that of 3C-SiC. In contrast to 3C-SiC, where no photoluminescence could be observed at room temperature, strong visible emi ssion with a peak energy of 2.2 eV could be seen from the nanocrystalline f ilms at room temperature. The presence of nanocrystalline cubic SiC in thes e films is believed to result in a change in their energy-band structure, c ompared to that of 3C-SiC, which promotes radiative recombination of electr on-hole pairs. (C) 2000 American Institute of Physics. [S0021-8979(00)04411 -X].