Surface reconstruction structures and epitaxial growth of Ag on the Si(111)-(√3 x √3)-Ag structure at 160K were investigated by reflection high-energy electron diffraction. When Ag was deposited on a (√3 x √3)-Ag surface at 160K, reconstruction structures √21 x √21 and 6 x 6 were observed in addition to the √3 x √3 structures. The √3 x √3 and √21 x √21 structures were observed for a thickness range between 0.19 and 2.6ML, and the 6 x 6 structures appeared and coexisted with the √3 x √3 and √21 x √21 structure between 0.7 and 1.7ML. From reflection high-energy electron diffraction patterns analysis, a 6 x 6 model was proposed. Beyond Ag growth of 3ML, three-dimensional Ag islands were formed at the temperature range from 160K to room temperature. These results imply that the mean free path of Ag atoms on the (√3 x √3)-Ag surface was large enough even at 160K that 2D nuclei cannot be formed on the terrace in spite of decreasing substrate temperature.

Reconstruction and Growth of Ag on the Si(111)-√3 x √3-Ag Surface at Low Temperature. Z.H.Zhang, S.Hasegawa, S.Ino: Physical Review B, 1995, 52, 10760-3