Nanoscale facet formation on Si(113)

Koichi Sudoh and Hiroshi Iwasaki

The Institute of Scinentific and Industrial Research, Osaka University,
8-1 Mihogaoka, Ibarak, Osaka 567-0047, Japan.

Si(113) vicinal surfaces are faceted below the respective faceting temperatures owing to short-range attractive step-step interactions. Previous studies [1] have shown that the average terrace width increases as t^1/6. In order to investigate the kinetics of faceting, we have performed real-time observation of surface morphology during faceting, using scanning tunneling microscopy. It is found that a two-dimensional network of step bunches coarsens via zipping up of neighboring step bunches in the later stage of the faceting. We have performed numerical simulation for step motion during faceting based on the continuum step model in which the attractive step-step interactions stabilizing step bunches and the smoothing effect of the line tension are taken into account, yielding a quantitative understanding of our observation and the time scaling behavior.

[1] S. Song et al. Phys. Rev. Lett.74, 3240 (1995) ; K. Sudoh et al., Jpn. J. Appl. Phys. 37, 5870 (1998).