Thermal annealing effect on ultraviolet-light-induced leakage current in low-pressure chemical vapor deposited silicon nitride films

We report the effects of isothermal annealing on the current component, the paramagnetic K0 centers, and charge accumulation, induced by exposing silicon nitride films and silicon nitride-silicon dioxide double-layer films to 4.9-eV ultraviolet (UV) illumination. The UV-induced current component decayed as a result of the isothermal annealing at temperatures ranging from 27 °C to 240 °C, and was induced once again by UV exposure following the annealing. The density of the current component showed a close correlation with the density of the K0 centers. Based on detailed analysis, we show that electron-hole pair generation in the bulk of the silicon nitride film is the possible source of the UV-induced current component.