Patent ID: 7432166

Claim:
A method of forming a nitrogen-enriched region within a silicon-oxide-containing layer, comprising: providing the silicon-oxide-containing layer over a substrate; the silicon-oxide-containing layer having a bare upper surface above the substrate and a lower surface on the substrate; exposing the silicon-oxide-containing layer to an activated nitrogen species from a nitrogen-containing plasma to introduce nitrogen into the silicon-oxide-containing layer and form a nitrogen-enriched region, the nitrogen-enriched region being only in an upper half of the silicon-oxide-containing layer; subsequent to the introduction of nitrogen into the silicon-oxide-containing layer, thermally annealing the nitrogen within the nitrogen-enriched region, while the bare upper surface of the silicon-oxide-containing layer remains bare, to bond at least some of the nitrogen to silicon proximate the nitrogen; the nitrogen-enriched region remaining confined to the upper half of the silicon-oxide-containing layer during the annealing; and wherein the nitrogen-enriched region is formed only in the upper third of the silicon-oxide-containing layer by the exposing and remains confined to the upper third of the silicon-oxide-containing layer during the annealing.