The process adaptability of Cu(0.7-1.2 at.% Mg) alloy films for microelectronics interconnects was investigated by comparing their electrical properties, interfacial adhesion strength, time dependent dielectric breakdown (TDDB) reliabilities, and interfaciat microstructure with those of pure Cu. The resistivity of the Cu(Mg) films decreased to similar to 2.0 mu Omega cm after annealing them in a vacuum at 350 degrees C for 10 min. The interfacial debonding energy measured by the four-point bending method was approximately 20.1 J/m(2) for Cu(Mg)/SiO2 which is a factor of 2.3 larger than that of Cu/SiO2 interfaces. The median time to failure of CU(Mg)/SiO2 in the TDDB test was much larger than that of pure Cu/SiO2. The diffusion of Cu into the dielectric was found to be inhibited by the continuous very thin Mg-O layer formed at the Cu(Mg)/SiO2 interface, which improves the interfacial adhesion, and ultimately leads to better electrical reliabilities. (c) 2007 Elsevier B.V. All rights reserved.