This book is devoted to the continuing research and development of thin-dielectric films for optical and microelectronic applications. Although thermal SiO2 has been the dominant dielectric for thin films in microelectronic applications for many years, there is a growing need for low-dielectric constant materials for interlevel dielectrics (less capacitive cross-talk and reduced delay) and high-dielectric constant materials to minimize the space and maximize the capacitance of storage devices such as DRAMs. With the demands put forth by the microelectronics community, this field is expected to develop significantly in the near future. Also featured is the growing area involving the structure and characteriza-tion of buried a-SiO2 layers formed by O+ ion implantation or the Smart Cut Unibond® process. These techniques are evolving into viable methods for producing commercial silicon-on-insulator substrates for device applications requiring radiation hardness, high-speed and low-power performance, and high-temperature operation.