An in-chip system and method for removing heat from integrated circuits is disclosed. One embodiment is a substrate with a front side and a back side. The front side of the substrate is capable of having formed thereon a plurality of transistors. A plurality of structures within the substrate contain a solid heat conductive media comprising carbon nanotubes and/or a metal, such as copper. At least some of the plurality of structures extend from the back side of the substrate into the substrate. In some embodiments, the carbon nanotubes are formed within the substrate using a catalyst.