SEMICONDUCTOR STRUCTURES AND METHODS FOR STABILIZING SILICON-COMPRISING STRUCTURES ON A SILICON OXIDE LAYER OF A SEMICONDUCTOR SUBSTRATE

Methods are provided for substantially preventing and filling overetched regions in a silicon oxide layer of a semiconductor substrate. The overetched regions may be formed as a result of overetching of the silicon oxide layer during etching of an overlying silicon-comprising material layer to form a silicon-comprising structure. An etch resistant spacer may be formed after the initial or subsequent overetches. The etch resistant spacer may be formed by depositing an etch resistant material into the overetched region and etching the deposited etch resistant material to leave residual etch resistant material forming the etch resistant spacer. The etch resistant spacer may also be formed by exposing the silicon oxide layer in the overetched region to a nitrogen-supplying material to form a silicon oxynitride etch resistant spacer.