The disclosure relates to a target and magnetron for a plasma sputter reactor (10). The target (12) has an annular vault (18) facing the wafer (20) to be sputter coated. Various types of magnetic means positioned around the vault create a magnetic field supporting a plasma extending over a large volume of the vault. Preferably, the magnetron (14) includes annular magnets (32) of opposed polarities disposed behind the two vault sidewalls (22, 24) and a small closed unbalanced magnetron of nested magnets (30) of opposed polarities scanned along the vault roof. An integrated copper via filling process with the inventive reactor or other reactor includes a first step of highly ionized sputter deposition of copper, which can optionally be used to remove the barrier layer at the bottom of the via, a second step of more neutral, lower-energy sputter deposition of copper to complete the seed layer, and a third step of electroplating copper into the hole to complete the metallization. The first two steps can be also used with barrier metals.