STM STUDIES OF SI EVAPORATION ON SI AT RT BY LASER-ABLATION

Silicon has been deposited on Si(111) under UHV by means of the pulsed laser evaporation technique. The evaporated species contain Si ions o f kinetic energies as high as 2 keV, i.e. much higher than in thermal evaporation. STM images of around 0.1 deposited monolayers reveal that some damage is produced on the substrate. The damaged areas consist m ainly in monatomic vacancies of the so-called internal adatoms in the unit cell. Triangular islands of lateral dimensions around 100 angstro m along [110BAR] directions have been found at variance with previous published results on thermal evaporation. The atomic density of the is lands appears to be smaller than that of the substrate and they contai n rows of paired atoms.