Wire-Like ordering of Si dopant atoms on GaAs-001- vincinal surgaces studied by raman scattering

Raman scattering in resonance with Edeep0 + Deltadeep0 band gap of GaAs has been used to study the ordered incorporation of Si dopant atoms on GaAs(001) vicinal surfaces. A Raman excitation at 120 cmhighminus1 was observed for a series of Delta-doped samples. The observed shape of the spectra can be explained by excitations of photo-created near-surface holes with a peak at 120cmhighminus1 overlapping with nonequilibrium huminescence at the Edeepo +Deltadeep0 band edge. A pronounced polarization asymmetry in the scattering intensity of this excitation was observed in a sample grown under conditions favorable for wire-like Si incorporation. The sensitivity of this polarization asymmetry to the wire-like dopant incorporation seems to be even stronger than that previously observed for intersubband plasmon-phonon modes excited in resonance with E1 band gap of GaAs.