STUDY OF THE QUALITY OF GaAs THIN FILM ON Si SUBSTRATE BY X-RAY DIFFRACTION METHOD

Different diffraction lattice planes were used to investigate the quality profiles of molecular beam epitaxy epi-layer GaAs films on Si substrate by X-ray double crystal diffraction method. As the X-ray incident angle increasing, the full width of half maximum (FWHM) also increases, that is , the quality getting worse in deeper layer. Therefore a clear figure of the degree of perfectness along the depth can be shown. The sample with strain surerlattice buffer layer has better quality than that without, especially in the surface lamella.