High gain, low noise, fully complementary logic inverter based on bi-layer WSe₂ field effect transistors

In this article, first, we show that by contact work function engineering, electrostatic doping and proper scaling of both the oxide thickness and the flake thickness, high performance p- and n-type WSe₂ field effect transistors (FETs) can be realized. We report record high drive current of 98μA/μm for the electron conduction and 110 μA/μm for the hole conduction in Schottky barrier WSe₂ FETs. Then, we combine high performance WSe₂ PFET with WSe₂ NFET in double gated transistor geometry to demonstrate a fully complementary logic inverter. We also show that by adjusting the threshold voltages for the NFET and the PFET, the gain and the noise margin of the inverter can be significantly enhanced. The maximum gain of our chemical doping free WSe₂ inverter was found to be ∼25 and the noise margin was close to its ideal value of ∼2.5V for a supply voltage of V_DD=5.0V.