Differential trench fill for ease of layout design

An integrated circuit structure comprises a plurality of structures above a substrate, wherein spacing between the structures creates a range of different open density regions from a relatively low open density region to a high open density region. A first fill material fills at least a portion of openings between the structures in at least the high open density region to provide a substantially uniform open density across the different open density regions, wherein the first fill material is patterned to include openings therein. A second fill material fills the openings between the structures in the low open density region, and fills the openings in the first fill material in the at least the high open density region.