Disclosed are apparatus comprising a substrate and techniques for fabricating the same. The substrate may include a first metal layer having signal interconnects on a first side of the substrate. A second metal layer may include ground plane portions on a second side of the substrate. Conductive channels may be formed in the substrate and coupled to the ground plane portions. The conductive channels are configured to extend the ground plane portions towards the signal interconnects to reduce a distance from individual signal interconnects to individual conductive channels. The distance may be in a range of seventy-five percent to fifty percent of a substrate thickness between the first metal layer and the second metal layer.