Influence of implantation and annealing temperatures on the irradiation damage in He2+ ion implanted 6H-SiC

•Lattice expansion, disorder level and defect concentration in He-implanted SiC are observed to decrease with increasing implantation temperature at the same irradiation dose.•6H-SiC irradiated at 400 °C and subsequently annealed at 750 °C shows lower lattice defect concentrations than when irradiated at 750 °C to the same dose.•The temperature effect on defect recovery process differs between dynamic annealing during irradiation and post-irradiation annealing at the same temperature and duration. Single crystal 6H-SiC samples were implanted with He2+ ions to 5 × 1016 cm−2 at 400 °C and 750 °C, and the sample implanted at 400 °C was subsequently annealed at 750 °C for 3 h in vacuum. These samples were characterized using X-ray diffraction, Raman spectroscopy, UV–Visible spectrophotometry and transmission electron microscopy. The results showed that the lattice expansion, level of disorder and defect concentrations in the He-implanted 6H-SiC has decreased with increasing implantation temperature at the same dose. There was a reduced irradiation effect in the 6H-SiC irradiated at 400 °C and subsequently annealed at 750 °C compared to the sample solely irradiated at 750 °C to the same dose. This behavior was attributed to more stable defect clusters and enhanced He trapping at defects in the latter sample. Possible He bubble effects cannot be excluded. In addition, the temperature effect on defect recovery in the dynamic annealing during irradiation and post-irradiation annealing was discussed.