PREPARATION OF COMPOSITIONALLY GRADIENT TI-TIN FILMS BY RF REACTIVE SPUTTERING

The r.f. reactive sputtering of a Ti target in a mixed gas of Ar and N-2 was used to fabricate compositionally gradient films consisting of Ti and TiN phases. In this paper, two methods are described to form the compositionally gradient Ti-TiN films. The first uses the N-2 flow-to-total flow ratio (F-N2/F-total) control method, and the other is the r.f. power control method. The compositionally gradient Ti-TiN films were deposited onto microscope glass slides. The substrate was at room temperature. The crystallographic structure, the composition and the morphology of the deposited films were characterized by X-ray diffractometry, Auger electron spectroscopy and scanning electron microscopy, respectively. Both the F-N2/F-total and r.f. power control method can be used to grow compositionally gradient films. It was demonstrated that the deposited film has a structure with a non-oriented TiN layer on a c-axis perpendicular Ti layer. The morphology of the films is independent of the deposition method. It is also shown that optical emission spectroscopy and mass spectroscopy are useful tools to monitor the growth of these films.