4H-SiC Oxide Characterization with SIMS Using a 13C Tracer

The SiO2/SiC interface is characterized for carbon accumulation using the carbon isotope 13C as a marker layer combined with secondary ion mass spectroscopy (SIMS). SiC was epitaxially grown using an isotopically enriched propane source and subsequently oxidized to a thickness required to consume the entire 13C layer. Mass specific depth profiles through the oxide film yield residual carbon concentrations at or below 3x1011 cm-2. The depth resolution of SIMS and natural abundance of 13C in the bulk SiC film limit sensitivity but allow us to set a limit of 2.5x1014 cm-2 carbon build up at or near the interface.