MICROSTRUCTURE AND ELECTRICAL PROPERTIES OF Al/TaNx MULTILAYERS

Al/TaNx multilayers were deposited on Al2O3 wafers by DC reactive magnetron sputtering. Microstructure and electrical properties of the samples were investigated in detail. The results show that more compact and smoother surfaces than that of TaNx thin films can be obtained in the Al/TaNx multilayers. Metal Al phases precipitate out from all the Al/TaNx multilayer samples. The main phases in the Al/TaNx multilayers are poor nitrogen phases when sputtered at lower nitrogen partial flux. However, rich nitrogen phases gradually precipitate out from the samples at higher nitrogen partial flux. With the increase of the nitrogen partial flux from 2 to 6%, the resistivity of the Al/TaNx multilayers increases from 640 to 1170 mu Omega.cm, and the temperature coefficient of resistance (TCR) of the samples increases from 46 to 350 ppm/degrees C. Compared with TaNx thin films, the resistivity and TCR of the Al/TaNx multilayers are all higher than those of the TaNx thin films.