Preferential orientation of titanium carbide films deposited by a filtered cathodic vacuum arc technique

Titanium carbide films with a thickness of approximately 100-nm were deposited on Si(100) substrates by a filtered cathodic vacuum arc technique. The composition and microstructure of the films were assessed by Rutherford backscattering spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and atomic force microscopy. A negative bias voltage (VS0∼−1000 V) was applied to the substrate during deposition, and the influence of VS on the crystalline orientation of the as-deposited films was investigated. It was found that the crystallites are randomly oriented in the film deposited at VS=0 V. In the bias voltage range of VS=−40∼−500 V, the titanium carbide films exhibited a (111) preferential orientation. When VS was increased to −1000 V, however, the film was (100) preferentially oriented. The compressive internal stress, determined by the radius of curvature technique, in the titanium carbide films exhibited a minimum value at approximately VS=−80∼−120 V. The (111) preferential orientation can be explained by minimization of elastic energy storage in the films; while the (100) preferential orientation in the film deposited at VS=−1000 V is due to the sputter channeling effect, because the (100) direction in the TiC lattice shows the most open channeling direction and therefore the lowest sputtering yield.