US Patent 11955381 Low-temperature plasma pre-clean for selective gap fill

Methods for pre-cleaning substrates having metal and dielectric surfaces are described. A temperature of a pedestal comprising a cooling feature on which a substrate is located is set to less than or equal to 100° C. The substrate is exposed to a plasma treatment to remove chemical residual and/or impurities from features of the substrate including a metal bottom, dielectric sidewalls, and/or a field of dielectric and/or repair surface defects in the dielectric sidewalls and/or the field of the dielectric. The plasma treatment may be an oxygen plasma, for example, a direct oxygen plasma. Processing tools and computer readable media for practicing the method are also described.