Formation of Si3N4 and SiC composite by nitrogen implantation

Silicon carbide was implanted with 50 keV nitrogen at elevated temperature up to 1100°C in order to form a composite of SiC and Si3N4. The depth profiles, the chemical state of the elements and the structure of the implanted surface were measured using Rutherford backscattering (RBS), nuclear resonance analysis (NRA), Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and glancing angle X-ray diffraction (G-XRD). With increasing nitrogen fluence a replacement of carbon by nitrogen took place and β-Si3N4 crystallites were formed on β-SiC surface at 1100°C, and the maximum concentration and halfwidth of the nitrogen profile implanted at 1100°C decreased in comparison with those implanted at <930°C. Preferential loss of graphite-like carbon produced by the nitrogen implantation was promoted by the irradiation with hydrogen radical beam during the nitrogen implantation, and the amount of β-Si3N4 crystallites gradually increased.