Patent ID: 9716065
Date: 2017-07-25
CPC Classifications: H01L

Claim:
1. A method comprising: forming a via opening through a trench to expose a portion of an underlying metal line; electrolessly plating a metal layer at a bottom of the via opening over the exposed portion of the underlying metal line, the electrolessly plated metal layer formed of a metal not including copper; depositing a cobalt layer to cover the bottom of the via opening over the electrolessly plated metal layer and sidewalls of the via opening; electrolessly depositing an additional metal layer over the electrolessly plated metal layer at the bottom of the via opening prior to the depositing of the cobalt layer, wherein the additional metal layer includes nickel, cobalt, or alloys of nickel and cobalt; growing a copper layer over the cobalt layer to form a line within the trench and a via filling the via opening; and annealing the trench and the via opening after the growing of the copper layer.