Scanning tunneling microscopy (STM) was used for studying nucleation and growth of 1-dimensional indium islands - chains - at coverage below 0.5 ML on the anisotropic reconstructed Si(100) 2×1 surface. The in-situ measurements were used to obtain density of the metal islands at various deposition rates and deposited amount of indium. In-vivo measurements, direct observation of the growth during the deposition, provided data on growth kinetics. Relaxation of the indium chains following after the deposition was recorded as well. The surface mobility of free metal adatoms at room temperature is too high and adatoms can be recorded by STM after reaching stable positions. Series of in-vivo images revealed a substantial role of C type defects [1] on the surface - as positions for adsorption of metal adatoms and stable terminations of indium chains. Evolution of size distribution of the growing chains with deposition time was obtained from in-vivo data. The size of indium chains was specified with atomic accuracy and STM images distinguished between termination of the chains by a single indium atom or dimer. The dynamics of indium atoms at the chain terminations we studied in [2] was completed by observation of attachment/detachment processes of individual indium atoms within an uncovered surface "basin" entirely surrounded by indium chains. The observations show that indium atoms can escape from that area - so a concept of "forbidden zones" along 1D metal chains (though they remain uncovered) suggested in growth models should be revised. Experimental data are summarized with respect of a realistic growth model.
[1] P. Kocán, P. Sobotík, and I. Ošt'ádal, Comment on "Monotonically decreasing size distributions for one-dimensional Ga rows on Si(100)", Phys. Rev. B 74, 037401 (2006)
[2] P. Kocán, I.Ošt'ádal, P. Sobotík, J. Javorský, M. Setvín, Stability of indium rows on Si(100)2×1 during growth and relaxation, accepted in Surface Science.
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