Graphene as a Thermal Management Material

IIT IS WELL RECOGNIZED THAT POWER CONSUMPtion and heat removal in state-of-the-art integrated circuits (ICs) with the nanometer size of transistors is an urgent challenge. The electronic industry’s transition to multicore designs, where the performance increase is achieved not via the increase in the clock frequency but rather through the increase in the number of processors, helped to alleviate some of the thermal issues but has not solved the problem of the nonuniformity of heat distribution inside a computer chip. The latter results in appearances of hot spots with heat fluxes exceeding 500 W/cm. The problems associated with the increased dissipated power densities have been encountered in optoelectronic and photonic devices as well. The thermal issues are further complicated by the fact that the material’s ability to conduct heat deteriorates when it is structured at the nanometer scale [1]. For these reasons, thermal management has to be improved not only at the packaging level but also at the nanoscale materials and device levels. THERMAL CHALLENGES AT NANOSCALE One of the approaches to mitigate the self-heating problem at the device-structure level is to incorporate materials with very high thermal conductivity into the chip design, i.e., the high-heat flux thermalmanagement approach. These thermally conductivematerials can be used to build either the device channel or interconnects themselves, or can be utilized as heat spreaders together with conventional electronic materials. It is also expected that improvements in thermal interface materials (TIMs) can be made by the utilization of these highly thermally conductive materials as new fillers. Another approach is to use solid-state thermoelectric onspot cooling, requiring efficient thermoelectric materials that can be integrated with the ICmaterials. Liquid coolingmay also play a more important role in future thermalmanagement technology.