Inhomogeneities in MBE-grown : a micro-Raman study

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