Evaluation of Intermetallic Compounds Selected From DFT Database

The calculated resistivity database was used to find low-resistivity intermetallic compounds (IMCs). The rare earth (RE)- copper compounds of RECu5 (RE=Er, Y, Yb)were found to show low resistivity. To confirm the calculated results and seek feasibility of using these IMCs for advanced interconnections, thin film samples were prepared and their properties were experimentally measured. Resistivity of the three IMCs was found to increase by the decrease of the film thickness to 10 nm, then to decrease to the same level of Cu by further decrease of the thickness from 10 to 5 nm. BTS test showed that ErCu5 had a good diffusion barrier property. The obtained results were attributed to the out diffusion of Er from the IMC film and the formation of the Er-Y oxide.