First-principles calculations of defects in oxygen-deficient silica exposed to hydrogen

Hydrogen-related defects and oxygen vacancies in silica are analyzed using first-principles density-functional calculations. Energetics, structures, charge-state levels, and hyperfine parameters are determined. These calculations identify the hydrogen bridge related to the ${E}_{4}^{\ensuremath{'}}$ center as the defect responsible for the stress-induced leakage current, a forerunner of dielectric breakdown of gate oxides in transistors.