Hydrogen-terminated Si(111) and Si(100) by wet chemical treatment: linear and non-linear infrared spectroscopy

Fourier transform infrared (IR) and sum frequency spectra of H-terminated S i(111) and Si(100), resulting from various chemical HF etchings, have been recorded. Comparisons between the relative intensity of the vibrational fea tures characteristics of mono-, di- and tri-hydrides, are indicative of som e orientations of the species at the surface. These are confirmed by the es timates of the components of the dynamical dipole moments which are derived from the analysis of the polarized IR spectra. (C) 1999 Elsevier Science B .V. All rights reserved.