MoS₂Field-Effect Transistor with Sub-10 nm Channel Length

Abstract

Atomically thin molybdenum disulfide (MoS₂) is an ideal semiconductor material for field-effect transistors (FETs) with sub-10 nm channel lengths. The high effective mass and large bandgap of MoS₂ minimize direct source-drain tunneling, while its atomically thin body maximizes the gate modulation efficiency in ultrashort-channel transistors. However, no experimental study to date has approached the sub-10 nm scale due to the multiple challenges related to nanofabrication at this length scale and the high contact resistance traditionally observed in MoS₂ transistors. Here, using the semiconducting-to-metallic phase transition of MoS₂, we demonstrate sub-10 nm channel-length transistor fabrication by directed self-assembly patterning of mono- and trilayer MoS₂. This is done in a 7.5 nm half-pitch periodic chain of transistors where semiconducting (2H) MoS₂ channel regions are seamlessly connected to metallic-phase (1T') MoS₂ access and contact regions. The resulting 7.5 nm channel-length MoS₂ FET has a low off-current of 10 pA/μm, an on/off current ratio of >10⁷, and a subthreshold swing of 120 mV/dec. The experimental results presented in this work, combined with device transport modeling, reveal the remarkable potential of 2D MoS₂ for future sub-10 nm technology nodes.