Yf. Wang et Tt. Tsong, STRUCTURES OF ATOMIC STEPS ON THE 7X7 RECONSTRUCTED SI(111) SURFACE, Physical review. B, Condensed matter, 53(11), 1996, pp. 6915-6918
We have carried out a systematic study of the structures of mono bilay
er atomic steps on the 7X7 reconstructed Si(111) surface whose step ed
ges are parallel to the unit-cell boundary. Atomic steps in all possib
le 14 step groups have been observed; thus a complete picture of the s
tep structure is presented. The upper step edges of ten groups termina
te at unit-cell boundaries, while the remaining four groups do not. Th
e step structure formed is the result of two factors competing to mini
mize the surface free energy: the structural integrity of the upper st
ep edge and the width of the transition region at the lower terrace. T
here is evidence that step formation is influenced by the annealing me
thod used.