A major problem with current ICs, which gets much worse in 3D (stacked etc) designs, is keeping the transistors cool. The transistor has a maximum operating ju

A major problem with current ICs, which gets much worse in 3D (stacked etc) designs, is keeping the transistors cool. The transistor has a maximum operating junction temperature[1] which is limited by material and process. Higher density chips make it difficult to extract the generated heat, in order to keep those junctions cool. The heat is generated when the transistors switch from either on to off or vice versa, due to all normal conductors having some resistance, and switching a transistor involves sending or draining a small amount of current to its control element called the gate. Thus switching faster means more heat. More transistors in the same area all switching means more heat. So either by making it easier to wick away the heat, or by tolerating higher junction temperatures, a different material to silicon might allow for higher density or faster switching before heat becomes an issue. Of course there are other obstacles to increasing density and frequency, so just because a material has better thermal properties doesn't imply it'll allow for higher density or frequency. [1]: https://en.wikipedia.org/wiki/Junction_temperature https://en.wikipedia.org/wiki/Junction_temperature