Reaction of Si (100) with silane-methane low-power plasma: SiC buffer-layer formation

The formation of a SiC buffer layer on Si (100) at substrate temperature as low as 950 degrees C using radicals of methane molecules obtained in a low-power-density glow-discharge plasma, is presented. The x-ray photoemission spectroscopy and low-energy-yield spectroscopy performed in the constant final-state mode suggest that the layers obtained were stoichiometric. To understand the mechanism of heteroepitaxial silicon carbide growth, the early stage of SiC nucleation was observed by atomic force microscopy and reflection high-energy electron diffraction. The results reveal that three-dimensional epitaxial crystallites nucleate at the earliest growth stage followed by a further Volmer-Weber growth. (C) 1999 American Institute of Physics. [S0021-8979(99)04620-4].