AFM search for slow MCI-produced nanodefects on atomically clean monocrystalline insulator surfaces

We have investigated by means of atomic force microscopy (AFM) single impacts of slow singly and multiply charged Ar ions on atomically clean insulator surfaces for LiF(1 0 0), SiO2 (0 0 1) alpha-quartz, muscovite mica and sapphire c-plane Al2O3(0 0 0 1) crystals. The target samples have been continuously kept under UHV conditions by transferring them in a transportable UHV vault from the vacuum chamber for ion bombardment to the AFM instrument. Slow ion bombardment was accompanied by low-energy electron flooding to compensate for possible target surface charge-up. For Al2O3 clear ion-charge dependent surface defects in lateral and vertical directions give evidence for potential sputtering, which until now has only been demonstrated with thin polycrystalline insulator films. (C) 2003 Elsevier Science B.V. All rights reserved.