US Patent 10109490 Cobalt interconnects formed by selective bottom-up fill

Methods for forming interconnects that include cobalt. An interconnect opening is formed in a dielectric layer that penetrates from a top surface of the dielectric layer into the dielectric layer. A first cobalt layer is formed at a bottom of the interconnect opening and partially fills the interconnect opening. A second cobalt layer is selectively deposited on the first cobalt layer and grows upwardly from the first cobalt layer at the bottom of the interconnect opening.