Depth distribution of point defects in Si bombarded by high-energy N5+ and Si5+ ions

Abstract

Electron spin resonance has been used to study the depth distribution of point defects in Si samples bombarded by N5+ (E=16 MeV) and Si5+ (E=26.8 MeV) ions at 175 and 300 K in the dose range (4–8)×1015 cm−2. It was established that unlike the implantation of moderate-energy Si ions (E ∼ 100 keV), the depth distributions of planar tetravacancies in samples bombarded by ions at 300 K under these conditions have two maxima. The experimental results indicate that the tetravacancy density maximum closer to the surface is formed as a result of secondary defect formation processes. No continuous amorphous layer was observed in the bulk of any of the Si samples. This experimental observation is evidence of defect annealing which takes place when high-energy ions are implanted in Si.