This book brings forth fundamental aspects of silicon oxidation that are key to understanding the nature of ultra-thin oxides used in microelectronics. From the wet chemical pre-cleans prior to oxidation to oxygen diffusion in oxides, the chemical, structural and kinetic elements of oxidation are presented in a tutorial fashion at both an experimental and theoretical level. Experimental results are based on powerful techniques such as photon/electron spectroscopy, ion scattering and electron/tunneling microscopy. The theories, based on first principles, focus on atomic scale processes related to silicon oxidation. In contrast to previous books dealing with the structural and electronic properties of silicon oxide, this book is solely devoted to the formation and evolution of silicon oxide, including its nitridation.