Patent ID: 7736980

Claim:
A method of forming an apparatus, the method comprising: forming a plurality of deep trenches and a plurality of shallow trenches in a first region of a substrate, wherein at least one of the shallow trenches is positioned between two deep trenches, and wherein the plurality of shallow trenches and the plurality of deep trenches are parallel to each other; depositing a layer of conductive material over the first region and a second region of the substrate; etching the layer of conductive material to define a plurality of lines separated by a plurality of gaps over the first region of the substrate, and a plurality of active device elements over the second region of the substrate; masking the second region of the substrate; removing the plurality of lines from the first region of the substrate, thereby creating a plurality of exposed areas from which the plurality of lines were removed; and etching a plurality of elongate trenches in the plurality of exposed areas while the second region of the substrate is masked, wherein the elongate trenches have an intermediate depth between depths of the deep trenches and the shallow trenches.