Suppression of short channel effects in 5.1 nm WTe2 in-plane Schottky barrier field-effect transistors by Mo-doping

Single layer Schottky barrier field-effect transistors (SBFETs) composed of the in-plane (IP) hetero-junctions of 1T-WTe2(metallic phase WTe2) and 2H-WTe2(semiconducting phase WTe2) have been proposed in this paper. However, the transfer characteristic show that the 5.1 nm IP 1T-2H-1T WTe2 SBFET cannot suppress the short channel effect causing the leakage current beyond the OFF current (IOFF) requirement (0.1 mu A/mu m) of the International Technology Roadmap for Semiconductors (ITRS, 2013 version) for production in 2028. To solve this problem, we replace the W atoms of 2H-WTe2 near the source electrode with Mo atoms to conquer the short channel effect. We found that the leakage currents of the 5.1 nm IP 1T-2H-1T WTe2 SBFETs decrease gradually with the increase of the number of substitution Mo atoms. When the number of substitutions increases to six periods, the leakage drain current of the 5.1 nm IP 1T-2H-1T WTe2 SBFETs is lower than 0.1 mu A/mu m. Fortunately, the corresponding ON current (ION) is 961 mu A/mu m which also conforms to the ON current requirement (900 mu A/ mu m) of ITRS (2013 version) for production in 2028. Therefore, the monolayer WTe2 with the Mo atom substitution also can be used as the channel material in future 5 nm transistor.