Via electroless metal deposition and industrial plasma technology, we have successfully synthesized unique composite silicon nanowire structures with diamondlike carbon (DLC) sheaths acting as inorganic passivation layers. We have also discussed their growth mechanism in terms of a self-organization process. The thickness of the DLC sheaths were quantified with Raman spectroscopy. The Raman analytical result is in good agreement with direct microstructure observations. (c) 2006 American Vacuum Society.