Thermal Management in 3D IC Designs for Nano-CMOS Technologies: Analysis on Graphene- vs. Graphite-based TIM

With a high thermal conductivity of 3000-5000 W/m -K, Graphene outstands almost all materials in effective lateral heat spreading. Will introduction of 2D monolayer graphene in 3D-IC help in vertical heat conduction too? In this work, we investigate the impact of Graphene- and Graphite- -based inter-die thermal interface material (TIM) on the peak temperature of the 3D-IC. We compare configurations of additional intermediate layer (IL) of monolayer graphene, graphite and copper materials along with TIM. Simulations show a peak temperature reduction of up to 50°C in GSRC benchmarks. Role of thermal conductivity and the additional IL critical thickness in peak temperature reduction is also investigated. Our discussion encompasses the vertical thermal profile impact on TSV delay and peak temperature dependence on TIM material, thermal-conductivity and thickness. Lastly, of all configurations, we suggest to further investigate a very promising cost-effective graphite-based inter-die TIM along with graphite-based heat spreaders, to compensate the poor heat dissipation problem in 3D ICs.