On the applicability of single-layer integrated microchannel cooling in 3D ICs

The future 3D ICs may require high-performance cooling systems like integrated microchannels. However, the current 3D IC technology trend towards very thin silicon layers may prohibit manufacturing microchannels large enough to provide sufficient cooling performance. Therefore, in this paper we analyze the idea of single-layer cooling design, in which the microchannels are located only in one chip layer, the top layer which is not thinned because it does not contain vertical through-silicon vias. We use fully-coupled thermo-fluidic simulation to quantitatively compare this solution to standard multi-layer cooling designs. The results show that for some chips, namely when the number of tiers is low and when the height of thinned silicon layers is also low, a single-layer design can have comparable or better cooling performance than multi-layer design.