Effects of processing parameters on the properties of tantalum nitride thin films deposited by reactive sputtering

The effects of processing parameters on the properties of tantalum nitride thin films deposited by radio frequency reactive sputtering have been investigated. The influence of the N2 partial and (Ar + N2) total gas pressures as well as the sputtering power on the microstructure and electrical properties is reported. Rising the N2 partial pressure, from 2 to 10.7%, induces a change in the composition of the δ-TaN phase, from TaN to TaN1.13. This composition change is associated with a drastic increase of the electrical resistivity over a 7.3% N2 partial pressure. The total gas pressure is revealed to strongly affect the film microstructure since a variation in both composition and grain size is observed when the gas pressure rises from 6.8 to 24.6 Pa. When the sputtering power varied between 50 and 110 W, an increase of the grain size related to a decrease of the electrical resistivity is observed.