Thermal management with graphene lateral heat spreaders: A feasibility study

Following an experimental discovery of its extremely high thermal conductivity, graphene was proposed as material for heat removal. To evaluate the feasibility of graphene´s use for thermal management we simulated heat propagation in siliconon- insulator (SOI) structures with and without graphene or few-layer graphene (FLG) underlayers. A graphene heat spreader layer, when used, was sandwiched between the oxide layer and the Si substrate. The two ends of the graphene layer were attached to the side heat sinks, thus forming the lateral channel for heat escape. The simulations were carried out with the finite element method using COMSOL software. The thermal conductivity of graphene or FLG was assumed to be within the range from 1000 W/mK to 5000 W/mK. Our simulations have shown that for a given set of parameters of the device structure and a number of transistors the maximum temperature in the hot spots decreased by 70 K when graphene layers were embedded in the chip. The effect of the graphene lateral heat spreaders was more pronounced when the number of transistors increased. The obtained results suggest that graphene and FLG heat spreaders have a potential for the hotspot removal while incorporated in the chip design or used as filler in the thermal interface materials.