PREPARATION AND CHARACTERIZATION OF RF-SPUTTERED MULTILAYERED TIN-AU FILMS

TiN-Au films with multiple intermediate layers deposited by r.f. sputtering are suggested as a solution to the problem of adhesion of gold films to TiN coatings. Their optical and mechanical properties are investigated and compared with those of conventional electroplated gold films. Various analysis techniques have been used: Auger electron spectroscopy to determine the composition profiles, the direct tensile test for adhesion characteristics, optical rub test for scratch characteristics, salt spray test for corrosion characteristics and the selected ordinate method to identify the color of resultant films. It is shown that poor adhesion of gold films of TiN coatings can be overcome. Resultant multilayered TiN-Au films show the same color as that of commercially available electroplated gold films and their reflectivity reaches 98% of that of gold films over the wavelength range studied. For further applications, electrical properties of multilayered TiN-Au have also been studied. The sheet resistance of these TiN-Au films on n-Si and p-Si is in the range 0.54-OMEGA/square-6.12-OMEGA/square. Thus these multilayered structures may be used as durable contacts for microelectronic applications.