One embodiment of the present invention is a method for making metallic
interconnects over a substrate, the substrate having a patterned
insulating layer which includes at least one opening and a field
surrounding the at least one opening, the at least one opening has
sidewalls and bottom and a width of less than about 0.13 .mu.m, and the
method includes: (a) depositing by a PVD technique a PVD seed layer over
the substrate, said PVD seed layer being sufficiently thick over the
field to enable uniform electroplating across the substrate; (b)
depositing by a CVD technique a CVD seed layer over the PVD seed layer,
wherein (i) the CVD seed layer having a thickness of less than about 150
.ANG. over the field, (ii) the CVD seed layer is continuous over the
sidewalls and bottom surfaces, (iii) at least one of the seed layers
includes a material selected from a group consisting of Cu, Ag, or alloys
including one or more of these metals, and (iv) the seed layers inside
the at least one opening leave sufficient room for electroplating inside
the at least one opening; and (c) filling the at least one opening by
electroplating a metallic layer over the CVD seed layer, wherein the
electroplated metallic layer includes a material selected from a group
consisting of Cu, Ag, or alloys including one or more of these metals.