Figure 3

AFM topographic images obtained from silicon samples. (a) Pristine silicon and those exposed to 500 eV argon ions at an incidence angle of 70° to various fluences: (b) 1 × 10¹⁷, (c) 2 × 10¹⁷, (d) 5 × 10¹⁷, (e) 10 × 10¹⁷, (f) 15 × 10¹⁷, and (g) 20 × 10¹⁷ ions cm^-2, respectively. The corresponding height scales for (a to g) are the following: 1, 4.3, 9.9, 39.5, 85.7, 60.9, and 182.2 nm. For clarity, (a to c) represent images acquired over a scan area of 1 × 1 μm², whereas (d to g) are of scan area 2 × 2 μm². Insets show the 2D autocorrelation functions for corresponding images.