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In this study, the effects of uniform helium (He) ion implantation and annealing on strontium (Sr) implanted SiC were investigated. 300 keV Sr ions were implanted to a fluence of 2×10^16〖cm〗^(-2) at room temperature (RT). Some of the Sr implanted samples were then uniformly implanted with He ions to a fluence of 1.2×10^17〖cm〗^(-2) at RT. The individual and co-implanted samples were annealed at 1000°C for 5 hours. Raman spectroscopy and Rutherford Backscattering Spectrometry were used to investigate the structural evolution and migration behaviour of Sr + He implanted SiC. Sr implantation in SiC led to the disappearance of SiC characteristic peaks and appearance of homonuclear Si-Si and C-C peaks, indicating amorphization of SiC structure. Co-implantation of He caused similar damage, with additional graphitization (D and G peaks) associated with He-induced defects. Annealing at 1000°C partially restored SiC crystallinity, with the reappearance of SiC peaks and a reduction in defect-related features. Sr-only samples exhibited greater migration upon annealing, while co-implanted samples showed reduced Sr migration. This indicates that uniform He implantation suppresses Sr mobility by forming He-induced defects, such as bubbles and voids that trap Sr ions and hinder their diffusion, thereby enhancing retention within SiC.
