Over the various chapters, this thesis describes the characterization and development of a number of applications of silicon dioxides. An oxynitride is developed allowing a much higher SiGe epitaxial deposition rate in a bipolar process. Also a tunneloxide for non volatile memory application is developed and characterized. Once the oxide has been formed and defined it is exposed to the sometimes harsh environments during the following processing steps. Possible process damage due to this exposure is characterized, evaluation methods are developed, process steps are engineered for damage reduction and protection methods are developed.