Integrated circuitry comprising devices electrically coupled through a plurality of interconnect levels in which lines of a first and second interconnect level are coupled through a planar slab via. An interconnect line may include a horizontal line segment within one of the first or second interconnect levels, and the slab via may be a vertical line segment between the first and second interconnect levels. A planar slab via may comprise one or more layers of conductive material, which have been deposited upon a planarized substrate material that lacks any features that the conductive material must fill. A planar slab via may be subtractively defined concurrently with a horizontal line of one or both of the first or second interconnect levels.