Vacancy clusterization during thermal annealing of silicon carbide irradiated by hard ions

Consideration is given to results of positron studies of structural defects of vacancy type, formed in silicon carbide (SiC) monocrystals under irradiation by heavy ions, as well as evolution of these defects during isochronons annealing. SiC monocrystals of 6H polytype were investigated. Samples had n-type of conductivity. It is shown that irradiation of silicon carbide monocrystals by 120Xe ions with ∼1 MeV/nucleon energy leads to formation of vacancy defects, concentrated in near-the-surface layer of ∼14 μm thickness. Irradiated system becomes unstable during annealing, beginning from the critical fluence of xenon ions, equal to ∼5x1013 cm-3. This results to clusterization of primary vacancies in the 500-1000 deg C range