Embodiments of the invention include a method for forming a copper
interconnect having a bi-layer copper barrier layer. The method comprises
the steps of providing a substrate with a low-K dielectric insulating
layer and an opening in the insulating layer. A first barrier layer of
tantalum/tantalum nitride is formed on the insulating layer and in the
opening. A second barrier layer consisting of a material selected from
the group of palladium, chromium, tantalum, magnesium, and molybdenum is
formed on the first barrier layer. A copper seed layer is formed on the
second barrier layer and implanted with barrier ions and a bulk copper
layer is formed on the seed layer. The substrate is annealed and subject
to further processing which can include planarization.