Composite copper wire interconnect structures and methods of forming

摘要

Various embodiments include interconnect structures and methods of forming such structures. The interconnect structures can include a composite copper wire which includes at least two distinct copper sections. The uppermost copper section can have a thickness of approximately 1 micrometer or less, which inhibits surface roughening in that uppermost section, and helps to enhance cap adhesion with overlying layers.

主权项

1. An interconnect structure comprising:
a substrate having a recess with a bottom surface and sidewalls; a composite copper wire formed within the recess in the substrate, the composite copper wire including:
a liner layer over the bottom surface and the sidewalls of the recess;a first copper layer over the liner layer, the first copper layer having a first thickness of approximately two micrometers or greater;a copper grain growth barrier layer over the first copper layer; anda second copper layer over the copper grain growth barrier layer, the second copper layer having a second thickness that is substantially less than the first thickness, the second thickness inhibiting surface roughness in the second copper layer.