Patent ID: 8329587

Claim:
A method of processing a silicon-and-oxygen-containing layer on a patterned substrate having a narrow trench and a recessed open area, the method comprising: forming a carbon-free silicon-and-nitrogen-containing layer on the patterned substrate including in the narrow trench and in the recessed open area by chemical vapor deposition and converting the carbon-free silicon-and-nitrogen-containing layer to the silicon-and-oxygen-containing layer; planarizing the silicon-and-oxygen-containing layer leaving a narrow gapfill portion in the narrow trench and a wide gapfill portion in the recessed open area, wherein planarizing the silicon-and-oxygen-containing layer comprises removing a portion of the silicon-and-oxygen-containing layer above the narrow trench and exposing a post-planarization dielectric interface disposed closer to the narrow trench than a corresponding pre-planarization dielectric interface; and treating the substrate, after the planarizing operation, to increase a density of the narrow gapfill portion, wherein the post-planarization dielectric interface disposed closer to the narrow trench allows the narrow gapfill portion to become denser than had the substrate been treated before the planarizing operation.