Amorphous structures of silicon carbonitride formed by high-dose nitrogen ion implantation into silicon carbide

Abstract

Short-range order in amorphous silicon carbonitride (a-SiC x N y ) has been examined using transmission electron microscopy. Single crystals of 6H-SiC with [0 0 0 1] orientation were implanted with 180 keV nitrogen ions at ambient temperature to a fluence of 5 × 10 17 N +/cm 2, followed by thermally annealing at 1500 °C for 30 min. A fully amorphous layer was formed at the topmost layer in the as-implanted sample. A part of the amorphous phase transformed into crystalline SiC after annealing. Radial distribution functions extracted via nano-beam electron diffraction patterns clearly showed that atomistic structures of the ion-beam-induced amorphous phase are different from those of the remaining amorphous phase in the annealed sample: a-SiC x N y possesses an intermediate bond length between Si–C and Si–N, while Si–N and Si–C bonds become more pronounced in the amorphous layer of the annealed specimen.