Variable-temperature scanning tunnelling microscopy was used to characterize the surface defects which were created by the 4.5keV He-ion bombardment of (001) surfaces at 80 to 294K. Surface defects were created directly by ion bombardment and by the diffusion of bulk defects to the surface. The heights and areal densities of adatoms, dimers and adatom clusters at 80 and 130K were approximately independent of temperature and were in reasonable agreement with molecular dynamics calculations of adatom production. At 180K, the areal density of these surface features was enhanced by a factor of about 3. This result was explained in terms of the migration and surface trapping of bulk interstitials which were formed within some 2nm of the surface.

Surface Defects and Bulk Defect Migration Produced by Ion Bombardment of Si(001) K.Kyuno, D.G.Cahill, R.S.Averback, J.Tarus, K.Nordlund: Physical Review Letters, 1999, 83[23], 4788-91