Insights into High-Dose Helium Implantation of Silicon

The paper reports an analysis of surface morphology variation and cavity pattern formation in silicon single crystal induced by ion implantation and post-implantation annealing in different regimes. Critical implantation doses required to promote surface erosion are determined for samples subjected to post-implantation annealing and in absence of post-implantation treatment. For instance, implantation with helium ions to fluences below 3 × 10¹⁷ He⁺/cm² without post-implantation annealing does not affect the surface morphology; while annealing of samples implanted with fluences of 2 × 10¹⁷ He⁺/cm² and higher promotes flaking.