Combined conformal/non-conformal seed layers for metallic interconnects

摘要

One embodiment of the present invention in a method for making copper interconnects, which method includes: (a) forming a patterned insulating layer on a substrate, the patterned insulating layer including at least one opening and a field surrounding the at least one opening; (b) depositing a barrier layer over the field and inside surfaces of the at least one opening; (c) depositing a non-conformal first copper seed layer over the barrier layer using physical vapor deposition, wherein the first seed layer is thicker than about 500 Å over the field; (d) depositing a conformal second copper seed layer over the first seed layer using chemical vapor deposition; and (e) electroplating a copper layer over the second seed layer.