MATERIALS AND INTERFACES CHARACTERIZATION BY MICRO-RAMAN SPECTROSCOPY

Several aspects of Raman and micro-Raman spectroscopy are shown and applied for the characterization of semiconductor materials and bi-layers of semiconductor on semiconductor and insulator on semiconductor. As a molecular technique, Raman spectroscopy will inform not only on the nature of elements but also on chemical bonds between atoms. Raman spectroscopy also permits the studies of disordered or amorphous materials. Based on the anisotropy in Raman scattering, the determination of the orientation of surfaces and thin layers becomes also easy. Micro-Raman spectroscopy, with a spatial resolution of the order of 1-mu-m2, allows the study of heterogenous or very small materials. This technique is very helpful in the determination of heterogeneity, stress and gradient in semiconductors. On step-etched or bevelled samples of a bi-layer, micro-Raman spectroscopy helps to examine the epitaxy quality of the deposit versus its thickness and also to detect eventual chemical bonds between deposit and substrate.