Little Influence of Kinks on the Formation ofc(4×2)Domains in a Si(001) Surface at Low Temperature

The structure of a Si(001) surface with monatomic steps is investigated by means of scanning tunneling microscopy at 95 K and Monte Carlo simulations (MCS) at various temperatures. In particular, we pay attention to the effect of kinks at the step edge on the formation of c (4×2) domains, and both studies reveal that the kinks do not govern the growth of the domains. MCS demonstrates that the nucleation of c (4×2) domains takes place at central regions of the terrace as a result of thermal fluctuation, and that the domains propagate to the step edge with decreasing temperature.