The Si(111) surface reconstructions were classified into 2 families, the 2 x 2 family: (2 x 2), c(2 x 4), c(2 x 8) and (√3 x √3) and n x n dimer–adatom–stacking-fault family. By in situ atomic scale observation of Si(111) surface reconstruction and by a statistical argument on the nucleation of a daughter phase in Si(111) matrix, It was found that the 2 x 2 family was a result of random motion of adatoms on a Si(11)-(1 x 1) substrate, while the n x n dimer–adatom–stacking-fault family could never be formed only by the movement of adatoms but some cooperative movement of substrate Si atoms was necessary.

Consideration of Atom Movement during Si Surface Reconstruction. I.Ohdomari, T.Watanabe, K.Kumamoto, T.Hoshino: Phase Transitions, 1997, 62[4], 245-58