The effect of O 2 ambient annealing on the microstructure of Cu(Mg) in the form of a Cu(Mg)/SiO 2 /Si multilayer

The effect of annealing in an O2 ambient on Cu(Mg)/SiO2/Si multilayer films was investigated. As-deposited Cu(Mg)/SiO2/Si multilayer samples with film thicknesses in the 1,000-3,000 A range were annealed for 30 min in oxygen ambients at pressures ranging from vacuum to 100 mtorr. The results showed that annealing in an 8-mtorr O2 ambient significantly decreased the electrical resistivity of a 1,000 A sample from 10.5 µΩ-cm to 3.7 µΩ-cm. Annealing in the O2 ambient enhanced Mg diffusion to the surface in comparison to vacuum annealing. Furthermore, O2 ambient annealing leads to excessive grain growth. However, the effect of O2 ambient annealing on resistivity is less when the thickness of the film increases.