Topographical characterization of Ar-bombarded Si(111) surfaces by atomic force microscopy

We used atomic force microscopy to study the topographical changes induced on Si(1 1 1) surfaces by 10-22 keV Ar+ bombardment. The irradiation was carried on normal to the surface with doses in the 1-60 x 10(16) ionS/cm(2) range. We observed a first generation of blisters at a critical dose around 3 x 10(16) ions/cm(2), which flakes off at 19 x 10(16) ions/cm(2), and a second generation of smaller blisters between 35 and 45 x 10(16) ionS/cm(2). Measurements of the mean surface height show that at low irradiation doses the surface inflates because of voids produced by Ar+ implantation. For doses greater than 20 x 10(16) Ar+/cm(2) the height decreases linearly because of sputtering, with a slope corresponding to a sputtering yield of 1.4. Finally, we present electron spectra produced during grazing proton bombardment of samples whose topography has been modified by Ar irradiation. (C) 2002 Elsevier Science B.V. All rights reserved.