Patent ID: 8795482

Claim:
An apparatus comprising: a wafer holder configured to hold a wafer, the wafer including field regions and recessed features; an electric field-imposing member; a controller configured to: (a) cause a deposition accelerator to become selectively attached to surfaces of the recessed features including: (i) causing the deposition accelerator to become attached to the field regions of the wafer and the surfaces of the recessed features of the wafer; and (ii) causing selective removal of deposition accelerator from field regions in close proximity to the electric field-imposing member to a greater extent than any corresponding accelerator removal from surfaces of the recessed features more remote from the electric field-imposing member than said field regions, the selective removal comprising an electrochemical process that is performed without performing substantial metal deposition onto the field regions and surfaces of the recessed features; and (b) after (a) is at least partially complete, cause the depositing of a metal onto the field regions and the surfaces of the recessed features, wherein the deposition accelerator remaining attached to the surfaces of the recessed features increases the rate of metal deposition onto the surfaces of the recessed features relative to the rate of metal deposition onto the field regions, and wherein the metal deposition continues until the recessed features are filled and the metal is protruding in regions of the recessed features relative to the field regions.