Swelling of ion-irradiated 3C-SiC characterized by synchrotron radiation based XRD and TEM

An experimental technique was established to characterize irradiation-induced volume swelling through a combined utilization of synchrotron radiation-based X-ray diffraction (XRD) and transmission electron microscopy (TEM). 3C-SiC specimens were irradiated by Si²⁺ ions (5 MeV) with fluences up to 5 × 10¹⁷ ion/cm² at 1000 °C. In order to avoid the accumulation of implanted Si ions in the SiC layer, specific thicknesses of the epitaxy layer and implanted ion energy were chosen. Unresolvable black spot defects were studied by TEM, and the average size and density were calculated. XRD radial scan results of surface (0 0 2), (1 1 1), (0 2 2), (1 1 3), and (2 0 0) including peak shift and asymmetry peak broadening were observed. Different interplanar spacing information of single crystal SiC can be obtained from this XRD measurement method, making it possible to investigate the lattice expansion and volume swelling more precisely. While TEM provided a direct visualization of the microstructures and the interplanar spacing was measured from HRTEM images. It is suggested that irradiation induced point defects and compressive stress from the Si substrate were the cause of anisotropic (a = b < c) volume swelling of irradiated 3C-SiC in this study.