Circuit-level requirements for MOSFET-replacement devices

Power consumption has grown to be the dominant challenge for continued CMOS scaling. This issue can be traced directly to the fact that the thermal voltage kBT/q does not scale, limiting the extent to which the MOSFET threshold voltage (VT) and hence the supply voltage (Vdd) can be scaled. To circumvent this limit, alternative switching device designs [1,2] which can achieve ≪60 mV/dec sub-threshold swing (S) have been proposed and demonstrated. However, many of these fail to maintain improved Ion/Ioff across a range of Vdd. In this paper, we apply circuit-level metrics to establish guidelines for assessing the promise of alternative switching devices for replacing the MOSFET.