In some embodiments, a fishbone structure in a power network includes a first conductive segment in a first conductive layer running in a first direction, a plurality of second conductive segments in a second conductive layer running in a second direction and a plurality of interlayer vias between the first conductive layer and the second conductive layer. The second direction is substantially vertical to the first direction. The plurality of second conductive segments overlap with the first conductive segment. The plurality of interlayer vias are formed at where the plurality of second conductive segments overlap with the first conductive segment. Each of the plurality of second conductive segments has a width such that the first conductive segment has a first unit spacing with a first adjacent conductive line or one of the plurality of second conductive segments has a second unit spacing with a second adjacent conductive line.