ANISOTROPIC DYNAMIC POLARIZATION OF SURFACE VIBRATIONS ASSOCIATED WITH H ON STEPPED SI(111)

Using polarized infrared spectroscopy, stretching and bending vibration modes of H chemisorbed on 4 degrees and -9 degrees misoriented Si(111) surfaces were investigated. Both the stretching and bending modes and their polarization responses were explained by surface structures such as monohydrides on a terrace, monohydride chains at the step edge of a (11 $$($) over bar 1) micro-facet and vertical dihydrides at the step edge of a (00 $$($) over bar 1) micro-facet. The dynamic polarizations for these bending vibration modes were anisotropic, i.e. the polarizations for the two step modes were along [($) over bar 110], while that of the terrace mode was in the (111) plane.