THE SUPERIORITY OF N2O PLASMA ANNEALING OVER O-2 PLASMA ANNEALING FORAMORPHOUS TANTALUM PENTOXIDE (TA2O5) FILMS

As-deposited tantalum pentoxide (Ta2O5) films are amorphous. The films will remain amorphous after low-temperature O-2 or N2O plasma anneali ng. High-temperature annealing will produce polycrystalline films wher e grain boundaries can generate leakage current. It was found that N2O plasma annealing is superior to O-2 plasma annealing in terms of leak age current reduction. This can be easily explained by the lower energ y required to break the nitrogen-oxygen bond in a N2O molecule compare d to the energy required to break the O=O bond in an O-2 molecule. We also observed that there is less Si contamination, which may lead to l eakage current, in the sample with N2O plasma annealing compared to th e sample with O-2 plasma annealing.