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

Abstract

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) MoS₂ channels using monolayer graphene as the Source/Drain contacts. The best devices, corresponding to DG 4-layer MoS₂-FETs with L_S/D=15 nm, had an I_on/I_off in excess of 10⁶ 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 MoS₂ FETs, indicating the high quality of the interface and the enhanced channel electrostatics.