High performance bilayer MoTe2 transistors with co-sputtered ternary HfAlO2 high-k dielectric

Abstract

We demonstrated that ternary HfAlO2 amorphous film prepared with common co-sputtering technology can be a suitable gate dielectric for bilayer MoTe2 transistors. The film quality can be improved by optimizing the sputtering process and post-annealing treatment, which is superior to its binary Al2O3 and HfO2 components and satisfies gate dielectric criteria. The bilayer MoTe2 transistors with ∼29-nm-thick HfAlO2 gate dielectric exhibit an Ion/Ioff ratio of over 108 by a low operating voltage, together with a small subthreshold swing ≈ 71.22 mV/dec. These promising characteristics favor the development of high-performance and low-power ultrathin MoTe2-based beyond-silicon electronics.