The effect of Si and Cu on the interactions between Al films and TiW barrier layer

The effect of Si and Cu doping of Al films on the interactions between the films and a TiW barrier layer was investigated. The results showed that Al12W was the primary product formed at the interface. Si-doping resulted in enhanced Al12W formation. When excess tungsten was present, Al12W reacted with W and formed compounds with a high W content. Prolonged annealing at 450 degrees celsius resulted in the formation of a hexagonal Al5W phase and a monoclinic Al4W phase in pure Al film.