N. Kitamura et al., VARIABLE-TEMPERATURE STM MEASUREMENTS OF STEP KINETICS ON SI(001), Physical review. B, Condensed matter, 48(8), 1993, pp. 5704-5707
Using a variable-temperature scanning tunneling microscope we have mea
sured the time evolution of the atomic-scale morphology of steps on Si
(001) at temperatures up to 350-degrees-C. Step-rearrangement events,
i.e., local changes in the atomic arrangements, are observed between s
uccessive images at temperatures above 225-degrees-C. The observed eve
nts always involve single or multiple units of four atoms and occur mo
st frequently at kink sites and at the ends of dimer rows. By measurin
g the event rate we determine an effective activation-energy barrier o
f 1.4-1.7 eV. The events cannot be completely characterized as success
ive random arrangements involving only single units. Rather, correlati
ons are observed between neighboring dimer columns, and the event rate
depends on the local atomic-step configuration.