15-nm channel length MoS2 FETs with single- and double-gate structures

We demonstrate single- and double-gated (SG & DG) field effect transistors (FETs) with a record source-drain length (L
S/D
) of 15 nm built on monolayer (t
ch
∼0.7 nm) and 4-layer (t
ch
∼3 nm) MoS
2
channels using monolayer graphene as the Source/Drain contacts. The best devices, corresponding to DG 4-layer MoS
2
-FETs with L
S/D
=15 nm, had an I
on
/I
off
in excess of 10
⁶
and a minimum subthreshold swing (SS
min.
) of 90 mV/dec. at V
DS
=0.5 V. At L
S/D
=1 µm and V
DS
=0.5 V, SS
min.
=66 mV/dec., which is the best SS reported in MoS
2
FETs, indicating the high quality of the interface and the enhanced channel electrostatics.