Silicon-on-insulator (SOI) structures formed in the top region of silicon wafers by ion implantation of oxygen were characterized by RBS (Rutherford Backscattering Spectrometry), OPM (Optical Microscopy), SEM (Scanning Electron Microscopy), and TEM (Transmission Electron Microscopy). Specimens taken from these wafers were previously subjected to specific thermal treatment and silicon epitaxial growth. The results of this investigation show that homogeneous, stoichiometric buried SiO₂ layers were formed beneath the silicon wafer surfaces after high-dose oxygen ion implantation (2.0 x 10¹⁸ O⁺/cm², 180 keV/O⁺). No buried SiO₂ layers were observed in the low-dose wafers (1.0 x 10¹⁷ O⁺/cm², 180 keV/O⁺). Solid-phase epitaxial regrowth (SPE) is strongly temperature dependent. The transition from amorphous (caused by ion impact) to crystalline through the SPE process is completed in the high-dose-rate wafers (∼33 μA/cm²), but not in the low-dose-rate wafers (∼17 μA/cm²). Polysilicon layers were formed on both sides of the SiO₂ layer in the low-dose-rate wafers. Evidence shows that both post annealing (>1000°C, 2 hours in N₂) and in-situ annealing (wafer substrate heating at 500°C during oxygen ion implantation) lower the imperfection density of the top surface region of silicon wafers. A silicon epitaxial layer with low levels of crystalline imperfections was able to be grown on these annealed wafers. The results also show that in-situ annealing is more effective than post annealing. The major microdefects in SOI structures observed in this investigation are dislocations.

The goal of this dissertation has been to develop techniques in order to use Brillouin spectroscopy as a tool for studying the elastic properties of thin films on a scale of ≃100 Å. In order to develop that capability we have built a tandem multi-pass Fabry-Perot interferometer, and that interferometer was used to study the elastic properties of Langmuir-Blodgett films. These films were chosen because they can be deposited one molecular layer at a time. As a result of these investigations we have measured the density and elastic constants of the Langmuir-Blodgett film cadmium arachidate. Samples of cadmium arachidate were prepared on molybdenum and BK-7 glass substrates. Data were accumulated for a range of thicknesses and for different scattering geometries. These data will be used to argue that guided acoustic waves were observed in a highly anisotropic film. The observed guided acoustic waves will be identified as a Rayleigh wave and a tight band of Sezawa modes. No Love modes were detected in these experiments; however, evidence for reorientational modes typical of anisotropic liquids was detected. The dispersion of the Rayleigh wave as a function of thickness together with thick film scattering data were used to estimate the elastic constants in cadmium arachidate. In particular the shear elastic constant c₄₄ was found to be a small value: c₄₄ < 4.0x10⁸ N/m². The remaining elastic constants were estimated, assuming hexagonal film symmetry, to be c₆₆ < 4.5x10⁹ N/m², C₁₁ ≃ 1.1x10¹⁰ N/m², c₃₃ ≃ 2.1x10¹⁰ N/m², c₁₃ ≃ 1.0x10¹⁰ N/m², and c₁₂ > 3.x10¹⁰ N/m². It is interesting to note that the acoustical behavior of cadmium arachidate is quite similar to the smectic phase liquid crystals (c₄₄ = 0).

Sol-gel derived silica coatings were deposited on soda-lime-silica by dip-coating. An absorbing metallic layer was sputtered onto the surface of the gel to couple near-infrared radiation from a Nd:YAG laser into the transparent coating. Laser energy was utilized to heat the ceramic coating on a substrate which has a lower glass transition temperature than the coating. Scanning the sample across the beam's path resulted in the formation of a 50 mum wide channel. The characteristics of a channel were altered by varying laser power, sol-gel coating thickness, and scanning speeds. Profilometry and SEM analysis verified that the coating can be heated to high temperatures without damaging the substrate.

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