Improved performance in MoS2 homogeneous junction field effect transistors by optimizing electrodes contact

Abstract

Junction field effect transistor (JFET) operates by controlling the thickness of depletion layer in channel with a reverse biased pn junction without dielectric issues, leading to high performance in nanoscale. Two-dimensional MoS2 has shown excellent electronic properties in atomic scale. MoS2 is an n-type semiconductor, therefore JFET based on MoS2 either adopts heterogeneous structure or doping of MoS2 needs to be done. Heterogeneous JFET suffers from lattice mismatching and other interface limitations. Homogeneous JFET with stable doping stands out. Herein, we propose a homogeneous JFET with stable doping by toroidal-magnetic-field controlled nitrogen plasma. The gate-channel pn homojunction in JFET exhibits excellent pn diode rectifying behavior with low reverse current. This JFET shows n-channel characteristics, and by improving contact between electrodes and MoS2, 102 improvement in mobility is demonstrated. The ON/OFF ratio reaches 104 in optimized JFETs.