Method and apparatus for remote plasma treatment for reducing metal oxides on a metal seed layer

A remote plasma apparatus for treating a substrate with a metal seed layer, the remote plasma apparatus comprising:

• a processing chamber;
• a substrate support for holding the substrate in the processing chamber, wherein a portion of the metal seed layer of the substrate has been converted to oxide of the metal;
• one or more cooling gas inlets above the substrate support in the processing chamber;
• a remote plasma source over the substrate support;
• a reducing gas inlet connected to the remote plasma source;
• a showerhead between the remote plasma source and the substrate support, wherein the one or more cooling gas inlets are positioned to provide cooling gas through the showerhead and/or provide cooling gas from an area peripheral to the substrate between the showerhead and the substrate support;
• and
• a controller configured with instructions for performing the following operations:
• forming a remote plasma of a reducing gas species in the remote plasma source, wherein the remote plasma comprises one or more of:
• radicals of the reducing gas species, ions of the reducing gas species, and ultraviolet (UV) radiation generated from excitation of the reducing gas species;
• exposing the metal seed layer of the substrate to the remote plasma in the processing chamber under conditions that reduce the oxide of the metal and reflows the metal in the metal seed layer;
• and
• flowing a cooling gas in the processing chamber from the one or more cooling gas inlets to cool the substrate after completion of exposing the metal seed layer to the remote plasma, the remote plasma apparatus being configured to cool the substrate to a temperature of about 30° C. in a span between about 40 seconds and about 100 seconds when flowing the cooling gas after completion of exposing the metal seed layer to the remote plasma.