First demonstration of DG monolayer MoS 2 FETs with 0.3 nm-thin contact extensions achieving near immunity to SCEs at L CH =20 nm and g m =206 μS/μm

In this work, we present the first demonstration of ultrathin (0.3 nm) contact extensions in ultra-scaled dual gate (DG) MoS2FETs to address short-channel effects (SCEs) induced by ‘contact gating’ - a key limitation in existing 2D FETs. The ultra-scaled DG devices feature channel lengths (LCH) down to 20 nm and a combined equivalent oxide thickness (EOT) of 0.75 nm, with on-currents reaching 460 μA/μm and maximum transconductance values reaching 206 μS/μm at VDS=1 V, the highest reported for 20 nm channels. Moreover, due to the ultra-thin contact extensions, our devices exhibit near immunity to SCEs. The off-state performance specs outperform prior reported data on 20 nm FETs, with minimal subthreshold slope (SS) degradation at 20 nm (< 25% increase compared to long-channel device), SS= 97 mV/dec, DIBL=30 mV/V, and a near zero threshold voltage. This work marks a key step toward aggressively scaled logic devices based on 2D materials.