A semiconductor device comprising at least one modified cell block that includes a modified abutment region in which is provided a first continuous active region arranged along a first axis parallel to a vertical abutment edge for positioning adjacent other cell blocks to form a vertical abutment, including non-standard, standard, and modified cell blocks. The structure provided within the modified abutment region improves a structural and device density match between the modified cell block and the adjacent cell block, thereby reducing the need for white space between vertically adjacent cell blocks and reducing the total device area and increasing cell density.