Method and apparatus for reducing metal oxide surfaces to modified metal surfaces are disclosed. Metal oxide surfaces are reduced to form a film integrated with a metal seed layer on a substrate by exposing the metal oxide surfaces to a reducing gas atmosphere comprising radicals of a reducing gas species. The radicals of the reducing gas species can form from exposing the reducing gas species to ultraviolet radiation and/or a plasma. The substrate is maintained at a temperature below a temperature that produces agglomeration of the metal seed layer during exposure to the reducing gas atmosphere, such as below 150° C. for copper. In some embodiments, the reducing gas species can include at least one of hydrogen, ammonia, carbon monoxide, diborane, sulfite compounds, carbon and/or hydrocarbons, phosphites, and hydrazine.