Methods of forming conductive pattern structures form an insulating interlayer on a substrate that is partially etched to form a first trench extending to both end portions of a cell block. The insulating interlayer is also partially etched to form a second trench adjacent to the first trench, and a third trench extending to the both end portions of the cell block. The second trench has a disconnected shape at a middle portion of the cell block. A seed copper layer is formed on the insulating interlayer. Inner portions of the first, second and third trenches are electroplated with a copper layer. The copper layer is polished to expose the insulating interlayer to form first and second conductive patterns in the first and second trenches, respectively, and a first dummy conductive pattern in the third trench. Related conductive pattern structures are also described.