Scaling of MoS₂ Transistors and Inverters to Sub-10 nm Channel Length with High Performance

Abstract

semiconductors such as monolayer molybdenum disulfide (MoS 2 ) are promising building blocks for ultrascaled field effect transistors (FETs), benefiting from their atomic thickness, dangling-bond-free flat surface, and excellent gate controllability. However, despite great prospects, the fabrication of 2D ultrashort channel FETs with high performance and uniformity remains a challenge. Here, we report a self-encapsulated heterostructure undercut technique for the fabrication of sub-10 nm channel length MoS 2 FETs. The fabricated 9 nm channel MoS 2 FETs exhibit superior performances compared with sub-15 nm channel length including the competitive onstate current density of 734/433 μA/μm at V DS = 2/1 V, record-low DIBL of ∼50 mV/V, and superior on/off ratio of 3 × 10 7 and low subthreshold swing of ∼100 mV/dec. Furthermore, the ultrashort channel MoS 2 FETs fabricated by this new technique show excellent homogeneity. Thanks to this, we scale the monolayer inverter down to sub-10 nm channel length.

Nanoscale Channel Length MoS2 Vertical Field-Effect Transistor Arrays with Side-Wall Source/Drain Electrodes

“…We further examined the drain-induced barrier lowering (DIBL), a key parameter to characterize the immunity of the FET to the SCE Figure c exhibits the threshold voltage ( V th ) as a function of V DS .…”

“…Figure c exhibits the threshold voltage ( V th ) as a function of V DS . We extracted a DIBL value of about 333 mV/V using the formula DIBL = prefix− V th high − V th low V DS high − V DS low , where V th high and V th low are the threshold voltages at V DS high = 1 V and V DS low = 0.1 V, respectively. The obtained DIBL of the vertical FET is relatively satisfactory compared with those of the reported MoS 2 FETs with nanoscale channel length (Table ), indicating that the as-fabricated vertical device structure has better immunity to the SCE.…”

“…Furthermore, Wu et al fabricated a single MoS 2 FET with a channel length of 10 nm by exploiting the self-oxidization of aluminum to form an effective isolation between the source and drain electrodes . Recently, Tian et al reported a sub-10 nm FET by selectively etching and transferring an undercut graphene/BN heterostructure on the MoS 2 channel . Moreover, Xiao et al reported a single MoS 2 FET with a channel length of 7.5 nm by fabricating electrodes with sub-10 nm gaps using horizontally aligned single-walled carbon nanotubes as an evaporation mask .…”

2D Short‐Channel Tunneling Transistor Relying on Dual‐Gate Modulation for Integrated Circuits Application

“…[49] As V DS increases from 0.25 to 2 V, V T shifts from 0.398 to 0.377 V, which implies that the transistor DIBL is ultralow with 12 mV V −1 , outperforming that of most reported 2D FETs. [50][51][52] Detailed calculations for V T and DIBL are shown in Figure S6 (Supporting Information). It is noteworthy that the off-state current (I OFF ) is maintained in the range of 0.22 to 0.44 pA, much smaller than that in planar 2D-FETs.…”

Two-Dimensional Semiconductors and Transistors for Future Integrated Circuits

“…In recent years, two-dimensional (2D) semiconductors have become one of the focuses of international academics due to their ultrathin thickness, atomic-level flatness, and superior electronic properties. − Such features make 2D semiconductors possess natural advantages in minimizing SCEs and solving the critical issues encountered in scaling three-dimensional (3D) bulk semiconductors. − The realization of 2D transistors with high mobility, low contact resistance ( R c ), and near-Boltzmann-limit subthreshold swing (SS) demonstrates their great potential in achieving low-power integrated circuits. ,, For example, Intel explored 2D transistor scaling down to a Source-to-Drain contact spacing of 25 nm, comparable to state-of-the-art Si technology . In work led by TSMC, Wu et al demonstrated contact length scaling down to 30 nm with a low contact resistance of sub-100 Ω μm for monolayer MoS 2 channel transistors .…”