INHOMOGENEITIES IN MBE-GROWN GAAS ALXGA1-XAS - A MICRO-RAMAN STUDY/

By an extensive micro-Raman study, oval-defect-related morphological, compositional and carrier concentration inhomogeneities were studied i n MBE-grown GaAs and AlxGa1-xAs epitaxial layers. It was found that th e crystalline morphology changes from point to point in the same defec t. Though the films remain in a rather good crystalline state, the def ects are shown to induce stress/strain in these films. The carrier con centration at the oval defects was also found to be less than at the e pitaxial layers.