Effect of substrate preparation and deposition conditions on the preferredorientation of TiN coatings deposited by RF reactive sputtering

Titanium nitride (TiN) coatings have been deposited by RF reactive magnetro n sputtering of a titanium target, in an atmosphere of argon and nitrogen. The coatings were deposited using different deposition conditions of gas co mposition, total pressure and indicated substrate temperature, on to titani um substrates that had received different preparation treatments. The struc ture of the coatings was examined as a function of deposition conditions by X-ray diffraction, and the crystallographic orientation was determined by use of a texture coefficient. The coatings on ground titanium substrates de veloped a strong (111) orientation from the earliest stages of growth, alth ough the degree of orientation was dependent on deposition conditions. Alth ough gas composition had no effect on film orientation, the intensity of th e (111) orientation diminished with increasing pressure, as well as with in creasing substrate temperature. On polished titanium substrates, the initia l texture was (220), but this changed to (111) orientation with increasing coating thickness. The results are discussed in terms of thermodynamically stable orientations and the kinetics of coating development as a function o f atomic matching of the coating and substrate. (C) 2000 Elsevier Science S .A. All rights reserved.