MoS ₂ transistors with 1-nanometer gate lengths

Abstract

Scaling of silicon (Si) transistors is predicted to fail below 5-nanometer (nm) gate lengths because of severe short channel effects. As an alternative to Si, certain layered semiconductors are attractive for their atomically uniform thickness down to a monolayer, lower dielectric constants, larger band gaps, and heavier carrier effective mass. Here, we demonstrate molybdenum disulfide (MoS) transistors with a 1-nm physical gate length using a single-walled carbon nanotube as the gate electrode. These ultrashort devices exhibit excellent switching characteristics with near ideal subthreshold swing of ~65 millivolts per decade and an On/Off current ratio of ~10 Simulations show an effective channel length of ~3.9 nm in the Off state and ~1 nm in the On state.

1D SbSeI, SbSI, and SbSBr With High Stability and Novel Properties for Microelectronic, Optoelectronic, and Thermoelectric Applications

“…[1] Recently, 2D MoS 2 transistors with 1 nm gate lengths have been made using 1D singlewalled carbon nanotube gate electrode. [2] The introduction of semiconductors with large band gap, heavy effective mass, and low dielectric constant, like MoS 2 , can lead to further scaling of transistor dimensions with low direct source-to-drain tunneling currents. [3,4] Considering shrinking transistor dimensions, 1D semiconductors with such properties are highly sought.…”

“…[21][22][23][24][25][26] The last 5 years have witnessed the renaissance of these materials for photovoltaic applications beyond perovskites, [27][28][29][30][31][32][33][34] because (i) orienting crystal growth perpendicular to the substrate sustains excellent carrier transport along the chains, (ii) benign grain boundaries parallel to the chains are free of dangling bonds and hence cause little recombination loss, [35] and (iii) needle-like crystals aligned in the translational direction of the growth exhibit better photovoltaic response than their higher dimensional counterparts. [36] For applications in field-effect transistors, the Achilles' heel of bulk V-VI-VII semiconductors is smaller band gap, lighter effective mass, and much higher dielectric constant than 2D MoS 2 , [2,17,29,32] which seriously reduces their potential. Interestingly, we show for the first time that the bulk-to-1D transition is accompanied by an abrupt switch in band gap, effective mass, and dielectric constant, distinguishing 1D SbSeI as a promising channel material for next generation field-effect transistors.…”

Two-dimensional negative capacitance transistor with polyvinylidene fluoride-based ferroelectric polymer gating

“…[16][17][18][19] These materials, especially 2D semiconductors, have been widely applied in FETs to substantially reduce device size and power consumption. [20][21][22][23] Thus, 2D materials are the most promising candidates for future nanoelectronic devices. For 2D FETs, however, ordinary dielectric materials, such as SiO 2 , Al 2 O 3 , and HfO 2 , are usually selected as the gate dielectric; therefore, the working principle of such 2D FETs is the same as that of a conventional FET; accordingly, the SS limit (60 mV/dec) persists, hindering further reduction in power consumption.…”

Effective mass effect in attosecond electron transport

“…The mobility directly depends on the effective mass of the electron in the crystal lattice. Reduced-structure sizes in integrated circuits and recent innovations towards atomic-scale transistors [1,2] lead to electron transport happening over distances of a few Ångströms that electrons traverse on attosecond time scales. Given that the idea of an effective electron mass originates from the assumption of an unbounded periodic crystal [3], the question arises whether it is still a valid concept on atomic-length and sub-femtosecond timescales [4].…”