Raman study of disorder in laser-annealed III-V semiconductors

From Raman study of laser-annealed InP and GaAs semiconductors (both crystalline and ion-implanted) a conclusion is drawn that under certain conditions a disordered polycrystalline phase of the material rather than a monocrystalline one may be produced. The diagnostic of the disorder is based on the Raman polarization measurements as well as on phonon linewidths and frequency shifts and on plasmon-phonon damping. The calculations are performed of the ratios of phonon scattering intensities for a polycrystal with either random or preferential orientation of crystallites. The dependence of Raman line shape on crystallite sizes is evaluated. From comparison of calculated and measured data the degree of orientation and crystallites sizes are estimated. (author)