Sputter damage in Si (0 0 1) surface by combination of C60+ and Ar+ ion beams

The damage to the solid by low-energy single atomic projectiles and high-energy cluster ion beams is analyzed by evaluating the Si (0 0 1) surface after ion sputtering, with angle-resolved x-ray photoelectron spectroscopy (ARXPS), high-resolution transmission electron microscopy (HRTEM), and atomic force microscopy (AFM). The depth distribution of Ar and C was determined using ARXPS. It was found that the primary ion implant region thickness in the Si is estimated to be 2.34, 1.68, and 1.63 nm for Ar+, C60+, and mixed Ar+–C60+ sputtering, respectively. Similarly, 5–8, 4–6, and 3–5 nm thick rearranged layers were observed directly with HRTEM. The results indicate that cluster ion beams cause shallower damage to the solid. On the other hand, AFM revealed 0.44, 2.58, and 2.63 nm surface roughness indicating that cluster ion beams induce significantly rougher interfaces. This interfacial roughening will ultimately determine the depth resolution of the depth profile.