Stability of nitrided silicon dioxide deposited by reactive sputtering

Abstract

The electrical properties of nitrided silicon dioxide formed by reactive sputtering in Ar/O2/N2 plasma from the SiO2 target have been studied. The nitrogen mixing ratio was varied from 0% to 15%, with the argon mixing ratio kept at 80%. It is found that as more nitrogen is incorporated, the leakage current increases for electron injection from both aluminum and silicon. By nitrogen reactive sputtering, the interface states generation during constant current stress is greatly reduced in comparison with oxide sputtered in only an Ar/O2 gas mixture. A mixture ratio of Ar/O2/N2 equal to 80:15:5 is found to give optimum oxide quality with good resistance to interface states generation and low leakage current.