A (100) surface, with missing-dimer vacancies that formed a (2 x n) phase, was prepared by W deposition. Morphological changes were monitored by means of scanning tunnelling microscopy when the surface was terminated by H. The density of dimer vacancies was significantly reduced by the H termination; thus suggesting that the density of sub-surface W atoms decreased. The mechanism of this morphological change was explained in terms of chemisorption-induced surface segregation and the energetic instability of W atoms buried in the sub-surface of the H-terminated surface.

Reduced Density of Missing-Dimer Vacancies on Tungsten-Contaminated Si(100)-(2 x n) Surface by Hydrogen Termination. S.Matsuura, T.Hitosugi, S.Heike, A.Kida, Y.Suwa, T.Onogi, S.Watanabe, K.Kitazawa, T.Hashizume: Japanese Journal of Applied Physics - 1, 2000, 39[7B], 4518-20