Ultraviolet-induced annealing of hydrogen bonds in silica films deposited at low temperatures

Exposure of photodeposited silica to ultraviolet irradiation with wavelengths comprised between 170 and 250 nm is shown to cause full removal of Si—H bonds. The photoreaction occurs at low temperatures (0–200 °C) in the bulk of the films, is independent of the film thickness, and does not lead to the creation of dangling bonds. An important reaction path involves water groups in the silica films, while direct photolysis of Si—H bonds is ruled out.