Vacancy type defects in Al implanted 4H–SiC studied by positron annihilation spectroscopy

Abstract

Vacancy-type defects produced by 100 keV Al + ion implantation in epitaxial 4H–SiC have been studied by positron annihilation spectroscopy. The implantation dose varied from 3×10 13 to 1×10 15/cm 2 and the implantation temperature was 25–800°C. From the experimental results it is clear that the implantation at elevated temperatures reduces the number of vacancy type defects. Furthermore, the defect-cluster size depends on the implantation temperature, suggesting that the vacancies involved are mobile. The positron annihilation experiments also suggest that the defect profile extends deeper into the samples than expected from the deposited energy distribution and from previous Rutherford backscattering/channeling measurements.