Comparative study of Cu and CuAl0.3 wt.% films

Cu and CuAl0.3 wt.% films were deposited by DC magnetron sputtering on SiO2 or a Ta interlayer. They are characterized with respect to resistivity, sl ess, adhesion, roughness and microstructure. The Al concentration is homog eneous within the CuAl0.3 wt.% films and equals the target composition. Al is enriched at the surface after annealing. No Al precipitation or formatio n of intermetallic phases is observed. The addition of Al results in a decr eased roughness, which is caused by significantly smaller grains of nearly constant size. Adhesion on SiO2 (after annealing) and oxidation resistance are improved due to the addition of Al. The modified properties of the allo y are balanced with an increase in resistivity of 3.3 mu Omega cm after dep osition, which decreases to the bulk value of 2.6 mu Omega cm after anneali ng. Process parameters and target erosion profile are equal to pure Cu targ ets. (C) 2001 Elsevier Science B.V. All rights reserved.