Patent ID: 7449098

Claim:
A method of planar plating, the method comprising: (a) providing a work piece having a surface with recessed regions and exposed regions; (b) plating metal onto the work piece under conditions that promote bottom-up fill in high aspect ratio features, whereby recessed regions of the work piece having relatively high aspect ratio are filled with metal, while at least some recessed regions having relatively lower aspect ratio are not substantially filled; (c) after (b), causing a plating additive to become attached to the surface selectively in the recessed regions, with relatively little or no plating additive attached to an exposed surface; and (d) after (c) is at least partially complete, plating the metal onto the surface, whereby the additive selectively attached to the surface increases the rate of metal plating in the recessed regions relative to the rate of metal plating in the exposed regions, wherein (c) and (d) are performed during contact with a first solution and during contact with a second solution, respectively, and wherein the first solution comprises a greater concentration of the additive than the second solution, and wherein plating metal in (b) is performed using a plating solution that is different from the first solution.