Anisotropies in magnetron sputtered carbon nitride thin films

Carbon nitride CNx (0 less than or equal tox less than or equal to0.35) thi n films, deposited by reactive dc magnetron sputtering in Ar/N-2 discharges have been studied with respect to microstructure using electron microscopy , and elastic modulus using nanoindentation and surface acoustic wave analy ses. For growth temperature of 100 degreesC, the films were amorphous, and with an isotropic Young's modulus of similar to 170-200 GPa essentially una ffected by the nitrogen fraction. The films grown at elevated temperatures (350-550 degreesC) show anisotropic mechanical properties due to a textured microstructure with standing basal planes, as observed from measuring the Young's modulus in different directions. The modulus measured in the plane of the film was similar to 60-80 GPa, while in the vertical direction the m odulus increased considerably from similar to 25 to similar to 200 GPa as t he nitrogen content was increased above similar to 15 at. %. (C) 2001 Ameri can Institute of Physics.