A metal vapor deposition reactor includes a primary reactor chamber having a primary chamber enclosure comprising a ceiling and side wall. The reactor further includes a secondary reactor chamber having a secondary chamber enclosure and a metal source target within the secondary chamber formed of a metal species to be deposited on said semiconductor wafer. Process gas inlets furnish process gases into a region of the secondary chamber near a working surface of said metal source target. A D.C. power source connected across said metal source target and a conductive portion of said secondary chamber enclosure has sufficient power to support ionization of the process gas near the working surface of the metal source target whereby to form a plasma that sputters metal ions and neutrals from the working surface of the metal source target.