Characterization of TiN films deposited using multicathode unbalanced magnetrons

Abstract

Unbalanced magnetrons can be very effectively utilized to provide enhanced ion bombardment of the substrate/film couples during deposition, and in multicathode systems it should be feasible to coat complex three-dimensional components uniformly and reproducibly. In this research, titanium nitride films were deposited using multicathode unbalanced, reactive, magnetron sputtering under a variety of ion bombardment fluxes, ion energies, nitrogen partial pressures, and total system pressures. In addition, several titanium aluminum nitride films were deposited for comparison. Through the use of carefully characterized magnetic field geometries, ion current densities ranging from 2 to 6 mA/cm2 have been generated, giving rise to ion-to-deposited Ti-atom ratios ranging from approximately 1.4:1 to 6.3:1. The films have been characterized in terms of their physical properties, chemical composition, crystallographic orientation, and film structure. Most of the films are approximately 3 μm thick, exhibit critical adhesive loads in excess of 5 kg, and have Vicker’s microhardness values of 2000 or more. Chemical characterization was performed using a scanning electron microscope with energy dispersive x-ray analysis (EDAX), a scanning transmission electron microscope with EDAX, and an electron microprobe. The majority of the films examined showed (111) preferred orientations and distinct columnar grain structures. No layering or shadowing effects were observed in cross section transmission electron microscopy studies.