Characterization of SiC buffer layer formation by reaction of Si(100) surface with methane + hydrogen plasma

Abstract

This work, combining in situ surface science techniques (x-ray photoemission spectroscopy and reflection high-energy electron diffraction) and ex situ analytical techniques (atomic force microscopy and infrared absorption spectroscopy), studies the formation of an SiC buffer layer on Si(100) using radicals of methane molecules obtained in a low-power-density glow discharge plasma. An analysis of C 1s and Si 2p core-level shifts combined with examination of the valence-band curves suggests that the buffer layers obtained are stoichiometric. 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 islands nucleate at the earliest growth stage, showing a further Volmer–Weber growth until the formation of a carbon-rich surface. The sequence of events that occur during silicon surface carbonization will be discussed on the basis of a reported model. Copyright © 2000 John Wiley & Sons, Ltd.