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Topographical characterization of Ar-bombarded Si(1 1 1) surfaces by atomic force microscopy

Abstract:

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 × 1016 ions/cm2 range. We observed a first generation of blisters at a critical dose around 3 × 1016 ions/cm2, which flakes off at 19 × 1016 ions/cm2, and a second generation of smaller blisters between 35 and 45 × 1016 ions/cm2. 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 × 1016 Ar+/cm2 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. © 2002 Elsevier Science B.V. All rights reserved.