The scaling of silicon complementary metal–oxide–semiconductor (CMOS) technology has become increasingly challenging as transistor device channels become smaller and more difficult to electrostatically control. To overcome these issues, researchers have explored the potential of atomically thick channel materials, such as monolayers of the transition metal dichalcogenide molybdenum disulfide (MoS₂). However, demonstrations of monolayer MoS₂ transistors with commercially relevant sizes and performance have been limited. Wen-Chia Wu and colleagues now report monolayer MoS₂ transistors with sub-40 nm device lengths.

The researchers — who are based at the Taiwan Semiconductor Manufacturing Company, National Yang Ming Chiao Tung University and the National Applied Research Laboratories in Taiwan — created back-gated transistors that have antimony-based metal contacts and are fabricated within the thermal requirements of back-end-of-line processing. Transistors with channel lengths of 19 nm and contact lengths of 12 nm exhibited on-currents of around 1,100 μA μm^–1 at drain voltages of 1 V. The contact resistance at this contact length was calculated to be 190 Ω μm. Scaling of the channel length to 12 nm showed improved on-currents with minimal degradation in subthreshold swing or drain-induced barrier lowering.