RAMAN-SCATTERING INVESTIGATION ON THE ORDERED INCORPORATION OF SI DOPANT ATOMS ON GAAS(001) VICINAL SURFACES DURING MBE GROWTH

Using Raman scattering by local vibrational modes (LVM) and collective electronic excitations we have investigated the ordered incorporation of Si dopant atoms on vicinal GAAs(001) surfaces. LVM spectra reveale d for a sequence of delta-doped samples grown by molecular beam epitax yy (MBE) under specific conditions that the Si dopant atoms are predom inantly incorporated on Ga-sites even at a doping concentration as hig h as 1.8 x 10(13) cm(-2). For a sample grown under conditions establis hed by real-time high-energy electron diffraction (RHEED) to be favour able for the wire-like Si incorporation, a pronounced polarization asy mmetry in the Raman scattering intensity of collective intersubband pl asmon-phonon modes arising from the delta-doping layer has been found.