The study of thin film amorphous solids by Raman scattering will be employed to provide basic information on the dynamics and structural order of noncrystalline semiconductors. Raman studies will be utilized in thin and ultrathin film geometries. This includes "modified geometries" such as interfaces, voids, ultrasmall microcrystals and in ultrathin film island configurations. Information about the effects of these special geometries on the vibrational Raman spectra are studied. These experiments utilize Raman scattering enhancement methods to allow weak signal levels associated with such configurations to be explored. The growth of ultrathin film amorphous solids will be monitored by Auger electron spectroscopy and selected scanning transmission electron microscopy measurements. Raman scattering measurements will additionally be employed in thin film dilute alloys with tetrahedrally coordinated systems of amorphous semiconductors amorphous germanium and amorphous silicon to obtain information about structural modifications in the nonmetal-metal transition. Complementing these Raman studies will be optical adsorption and spectroscopic ellipsometry measurements of changes in the electronic states.