Low-energy electron diffraction intensity measurements were used to study the re-ordering of the Si(7x7) pattern, The latter was produced by vacuum annealing a (111)-oriented crystal of p-type material at 1000C. The surface was then irradiated using a laser beam. Annealing of the irradiated surface was studied by using LEED techniques to monitor the Si(1x1) to Si(7x7) transformation. Using a cross-cut method, it was estimated that the activation energy for migration on the (111) surface was 1.1eV.

Activation Energy for Migration on Silicon (111) Face. S.M.Bedair: Surface Science, 1974, 42[2], 595-9