A memory array device includes an array of memory cells located over a substrate, a memory-level dielectric layer laterally surrounding the array of memory cells, and top-interconnection metal lines laterally extending along a horizontal direction and contacting a respective row of top electrodes within the memory cells. Top electrodes of the memory cells are planarized to provide top surfaces that are coplanar with the top surface of the memory-level dielectric layer. The top-interconnection metal lines do not extend below the horizontal plane including the top surface of the memory-level dielectric layer, and prevent electrical shorts between the top-interconnection metal lines and components of memory cells.