Thermal annealing of light-induced metastable defects in hydrogenated amorphous silicon nitride

Exposure to ultraviolet light induces paramagnetic, metastable defects in hydrogenated amorphous silicon nitride (a-SiN1.6) thin films. The thermally induced decay of the light-induced paramagnetic defects follows a stretched exponential dependence on annealing time, exp [-(t/τ) β], and displays a temperature-dependent β and τ. These results indicate that a multiple trapping or a trap-controlled hopping mechanism is involved in the annealing process with an apparent activation energy of 0.43 eV.