An investigation was made of the influence of pulsed laser irradiation upon the surface structure of Si(111), GaAs(100), InP(100), and Au(100). The surfaces of these materials exhibited an equilibrium low-energy electron diffraction pattern that could be described by a (m x n) reconstruction. No (1 x 1) pattern was observed at room temperature; except upon impurity stabilization. The preparation of a clean (1 x 1) surface was interesting because it could lead to considerably easier theoretical evaluation. Pulsed laser irradiation was believed to be a means of preparing such surfaces. However, it was shown here that the surfaces obtained were not defect-free. Clean reconstructed surfaces were irradiated with increasing laser fluences. Above a threshold fluence, the superstructure low-energy electron diffraction spots disappeared; leaving only the (1 x 1) pattern and a slightly increased background. A more detailed examination of the low-energy electron diffraction patterns revealed a random distribution of steps beside ordered terraces. The step height was nearly equal to the bulk interplanar distance. The inter-step spacing ranged from 70Å for Si to 30Å for InP and GaAs and 15Å for Au. It was shown that these steps stabilized the (1 x 1) pattern.

Laser-Induced Surface Reconstruction of Semiconductors and Metals. J.M.Moison, M.Bensoussan: Surface Science, 1983, 126[1-3], 294-300