Synthesis of metastable carbon-silicon-nitrogen compounds by ion implantation

The feasibility of carbon-silicon nitride formation (beta-Si1.5C1.5N4, the homologue of equilibrium P-Si3N4 or hypothetical beta-C3N4) has been investigated by high dose N+ implantation into polycrystalline beta-SiC (cubic phase). Thin films were formed using 100 keV implantations with varying ion doses and target temperatures. X-ray diffraction with a position-sensitive detector and cross-sectional transmission electron microscopy revealed that the as-implanted surfaces contained similar to 0.1 mu m thick buried amorphous layers. Rutherford backscattering spectroscopy showed that the peak concentration of nitrogen saturated up to approximately 54 at.% with increasing doses, suggesting formation of a new phase. Key words: Carbon-silicon nitride, ion-implantation.