Reversible resistivity change of thin silver films in the spatial afterglow of a nitrogen discharge

Experiments are reported on the interaction of thin (d≈20 nm) evaporated silver films with the afterglow of an argon nitrogen microwave discharge. A strong increase in the resistivity of the thin silver film (from 2.2×10−8 to more than 10−3 Ω m) due to the interaction with the spatial afterglow of a nitrogen plasma was observed. The initial low resistivity could be recovered by increasing the sample temperature from room temperature to 420 K or by treatment with an argon plasma. The effect is thus reversible. Sputtering processes could not be observed in the spatial afterglow of nitrogen discharges. The experimental results are assigned to dissolved nitrogen compounds in the thin silver film. A possible mechanism for the reversible increase in film resistivity in the nitrogen afterglow may be strong electron localization at the nitrogen-induced lattice defects.