Methods and apparatus for processing substrates using an ion shield

Abstract

Methods and apparatus for processing a substrate are provided. In some embodiments, a method of processing a substrate having a first layer may include disposing a substrate atop a substrate support in a lower processing volume of a process chamber beneath an ion shield having a bias power applied thereto, the ion shield comprising a substantially flat member supported parallel to the substrate support, and a plurality of apertures formed through the flat member, wherein the ratio of the aperture diameter to the thickness flat member ranges from about 10:1-1:10; flowing a process gas into an upper processing volume above the ion shield; forming a plasma from the process gas within the upper processing volume; treating the first layer with neutral radicals that pass through the ion shield; and heating the substrate to a temperature of up to about 550 degrees Celsius while treating the first layer.

1 . A substrate processing apparatus, comprising:
 a chamber body defining a processing volume having an upper processing volume and a lower processing volume;   a substrate support disposed within the lower processing volume;   an ion shield disposed in the processing volume and dividing the processing volume into the upper processing volume and the lower processing volume, the ion shield comprising a substantially flat member supported parallel to the substrate support, and having a plurality of apertures formed through the substantially flat member, wherein the ratio of the diameter of the apertures to the thickness of the substantially flat member has a range of about 10:1 to about 1:10;   a biasing power source coupled to the ion shield;   a shield support disposed within the processing volume configured to support the ion shield above the substrate support in a substantially parallel orientation with respect to the substrate;   a heat source to provide heat energy to a substrate when disposed on the substrate support; and   an RF power source for forming a plasma within the upper processing volume.   
     
     
         2 . The apparatus of  claim 1 , wherein the upper processing volume is fluidly coupled to the lower processing volume substantially only through the ion shield. 
     
     
         3 . The apparatus of  claim 1 , wherein the biasing power source is configured to supply about 10 to about 2000 V DC or about 10 to about 2000 W of RF power to bias the ion shield. 
     
     
         4 . The apparatus of  claim 1 , further comprising a nitrogen-containing gas source coupled to the process chamber to provide a nitrogen-containing gas to the upper processing volume. 
     
     
         5 . The apparatus of  claim 4 , wherein the nitrogen-containing gas is ammonia (NH 3 ).