Method for forming a novel power grid structure for integrated circuit semiconductor chip devices that exhibits increased electromigration resistance by including diffusion blocking interlevel contacts and employing a regular array of conducting line elements with “phase shift” between adjacent tracks of segmented power busses. The novel grid structure includes a first metal layer including a first set of conducting line segments that are substantially parallel to one another and run in a first direction; a layer of diffusion blocking dielectric insulation above the first layer; a second metal layer including a second set of conducting line segments substantially parallel to each other and running in a second direction orthogonal to the first direction; and, interlevel contact studs disposed substantially vertically through the diffusion blocking dielectric insulation layer for electrically connecting aligned line segments of the first and second sets, wherein each segment of the first and second sets of line segments is limited to a predetermined length by a diffusion blocking boundary.