Method and system for improving dielectric film quality for void free gap fill

A method of forming a silicon oxide layer on a substrate, the method comprising:

• providing a substrate;
• forming a first silicon oxide layer overlying at least a portion of the substrate, the first silicon oxide layer including residual water, hydroxyl groups, and carbon species;
• exposing the first silicon oxide layer to a plurality of silicon-containing species at a pressure from about 10 mTorr to about 600 Torr, a temperature from about room temperature to about 900° C., for a time period ranging from about 1 second to about 3 hours, wherein at least a portion of the plurality of silicon-containing species is either reacting with at least a portion of the residual water and hydroxyl groups or being thermally decomposed to form a plurality of amorphous silicon components, the plurality of amorphous silicon components being partially intermixed with the first silicon oxide layer;
• annealing the first silicon oxide layer partially intermixed with the plurality of amorphous silicon components in an oxidative environment to form a second silicon oxide layer on the substrate, wherein at least a portion of amorphous silicon components are oxidized to become part of the second silicon oxide layer, and wherein unreacted residual hydroxyl groups and carbon species in the second silicon oxide layer are substantially removed.