Detection of excess crystalline As and Sb in III-V oxide interfaces by Raman scattering

Raman backscattering from oxidized GaAs and InAs yielded two anomalous peaks of large scattering strength which we have concluded to be from excess As in the interface between the oxides and underlying semiconductors. Similarly, we concluded that the two anomalous peaks from GaSb and InSb are from excess interface Sb. From the frequencies, line shapes, and polarization selection rules, we deduced that the excess As and Sb are in the crystalline semimetal phase, as distinct from the amorphous phase.