The process of fabricating Cu layers by displacement reaction is demonstrated. In our experiments, Ti was used and displaced in the chemical reaction process to form copper films. TiN was also adopted to improve adhesion between the copper and the dielectric layer. The effects of the process recipe on the structure and reliability of the Cu lines were studied. The obtained average electrical resistivity of the Cu films was 2.04 mu Omega cm after thermal annealing and 2.18 mu Omega cm for samples grown from a less-oxygen-containing solution. Study of the reliability showed that the activation energy of the copper interconnect was 0.92 eV, which is very close to the result for Cu films grown by sputtering. (c) 2005 The Electrochemical Society. All rights reserved.