Study of Si(111) Surfaces by Optical Second-Harmonic Generation: Reconstruction and Surface Phase Transformation

Abstract
Optical second-harmonic generation has been applied to the study of clean Si(111) 2×1 and 7×7 surfaces. By an analysis of polarization dependences of the two reconstructions, the symmetry properties of the surfaces have been determined. The 2×1 to 7×7 surface phase transformation during thermal annealing has also been monitored in real time by the second-harmonic technique.