Switching at Less Than 60 mV/Decade with a “Cold” Metal as the Injection Source
Fei Liu
Abstract
Power dissipation is a great challenge for the continuous scaling down and performance improvement of CMOS technology, due to the thermionic-current switching limit of conventional MOSFETs. In this paper, we show that this problem can be overcome by using a ``cold'' metal as the injection source of a transistor; these metals are different from conventional metals and can filter out high-energy electrons to break the ``Boltzmann tyranny.'' It is proved that the subthreshold swing of the thermionic current of a transistor using a ``cold''-metal contact can be much smaller than 60 mV/decade at room temperature. Specifically, the two-dimensional transition-metal-dichalcogenide (TMD) ``cold'' metals $\mathrm{Nb}{X}_{2}$ and $\mathrm{Ta}{X}_{2}$ ($X=\mathrm{S},\phantom{\rule{0.2em}{0ex}}\mathrm{Se},\phantom{\rule{0.2em}{0ex}}\mathrm{Te}$) are proposed as injection sources for FETs. Quantum transport simulations indicate that a promising switching efficiency and on-state current can be achieved using TMD ``cold''-metal injection sources, which is beneficial for energy efficiency.