This study investigated the effects of helium (He) and swift heavy ions (SHI) on polycrystalline silicon carbide (SiC) pre-implanted with silver (Ag). First, 360 keV Ag ions were implanted into polycrystalline SiC at room temperature (RT) to a fluence of 2×10¹⁶ cm⁻². A subset of these Ag-implanted samples was then co-implanted with 17 keV He ions at 500 °C to a fluence of 1×10¹⁷ cm⁻². All samples were subsequently irradiated with 167 MeV Xe ions (SHI) at RT to a fluence of 1×10¹⁴ cm⁻². The structural evolution and Ag migration were analyzed using Raman spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), and Rutherford backscattering spectrometry (RBS). Ag implantation alone produced an amorphous SiC layer approximately 270 nm thick. He co-implantation at 500 °C induced partial recrystallization, reducing the damaged layer thickness to ~260 nm and forming He nanobubbles. Subsequent SHI irradiation further modified the microstructure. In samples implanted only with Ag, SHs irradiation caused significant partial recrystallization, reducing the damaged layer to ~230 nm. In contrast, for the He co-implanted samples, SHI irradiation resulted in only limited recrystallization, reducing the damaged layer to ~240 nm. This indicates that the presence of He suppresses both recrystallization and defect recovery under SHI irradiation. No Ag migration was observed following either He co-implantation or subsequent SHs irradiation. However, He co-implantation induced the formation of surface whiskers, the height of which decreased after SHI irradiation, suggesting partial surface recovery. This work elucidates the complex interplay between defect creation and irradiation-assisted healing.
Chauke et al. (Sun,) studied this question.