Charged states of H atoms in defect-free ${\mathrm{SiO}}_2$ have been proposed from first-principles total-energy band-structure calculations within a framework of the local-density approximation. The polarities of the charged states are determined depending on the position of the Fermi level. A positively charged state forms an Si-(${\mathrm{OH}}^{+}$)-Si complex, while a negatively charged state forms an Si-${\mathrm{H}}^{\mathrm{-}}$ bond. Calculated vibrational frequencies of newly formed O-${\mathrm{H}}^{+}$ and Si-${\mathrm{H}}^{\mathrm{-}}$ bonds for each charge state are found to be lower than those for neutral O-H and Si-H bonds, so the H-originated charge traps are expected to be distinguishable by either Raman or infrared spectroscopies.

DOI:https://doi.org/10.1103/PhysRevB.55.13783