Patent ID: 8455352

Claim:
A method of processing a substrate disposed in a processing chamber, the method comprising: controlling a temperature of a substrate positioned in the processing chamber to about 80° C. or less; generating a first cleaning plasma from a first gas mixture with a first plasma-generating power, the first gas mixture comprising nitrogen trifluoride (NF 3 ) and ammonia (NH 3 ) and having an NH 3 /NF 3 molar ratio of about 5 or greater; condensing products of the first cleaning plasma onto the substrate to form a thin film during a plasma clean process while controlling the temperature of the substrate to about 80° C. or less, wherein the thin film comprises ammonium hexafluorosilicate ((NH 4 ) 2 SiF 6 ) formed in part from a silicon oxide (SiO x ) layer disposed on a surface of the substrate; heating the substrate within the processing chamber to a temperature of about 100° C. or greater to remove the thin film from the surface; generating a second cleaning plasma from a second gas mixture with a second plasma-generating power, the second RF plasma- generating power being greater than the first plasma-generating power and the second gas mixture comprising nitrogen trifluoride; and exposing the surface to products of the second cleaning plasma while maintaining the substrate at the temperature of about 100° C. or greater.