Figure 2

Bright-field TEM images of c-Si samples irradiated with (a)–(c) 6 MeV C₆₀⁺, (d)–(f) 4 MeV C₆₀⁺, (g,h) 1 MeV C₆₀⁺, and (i) 200 MeV Xe¹⁴⁺ ions. All the samples were prepared by the pre-thinned configurations, except (c), (f), and (h) by the post-thinned configurations. Although both 200 MeV Xe¹⁴⁺ ions and 4 MeV C₆₀ ions provide almost the same S_e in c-Si, tracks were not observed in the former case, as shown in (i). While 4 and 6 MeV C₆₀⁺ ions exhibit almost straight tracks (c,f), 1 MeV C₆₀⁺ ions exhibit skewed tracks, which could indicate crossover from ion tracks to collision cascades.