The effects of nitrogen partial pressure on the properties of the TaNx films deposited by reactive magnetron sputtering

This paper concentrates on the mechanical, the electrical, and the acoustical properties of the Ta–N films deposited by radio frequency (rf) magnetron reactive sputtering in Ar/N2 gas mixtures. As the nitrogen partial pressure increased, a microstructure transformation of the films from columnar polycrystalline to amorphous was observed, and the differences on the acoustic properties were measured by the picosecond ultrasonic technique. We also found that the electrical resistivities of TaNx films rose steeply by six orders of magnitude owing to the lack of extra nitrogen as the donors, and excess electron scattering caused by the porous structure.