Two-dimensional semiconductors have a number of valuable properties that could be used to create novel electronic devices. However, creating 2D devices with good contacts and stable performance has proved challenging. Here we show that transferred via contacts, made from metal embedded in insulating hexagonal boron nitride and dry transferred onto 2D semiconductors, can be used to create high-quality 2D transistors. The approach prevents damage induced by direct metallization and allows full glovebox processing, providing a clean, stable and damage-free platform for 2D device fabrication. Using the approach, we create field-effect transistors (FETs) from bilayer p-type tungsten diselenide (WSe2) that exhibit high hole mobility and low contact resistance. The fabricated devices also exhibit high current and stability for over two months of measurements. Furthermore, the low contact resistance and clean channel allow us to create a nearly ideal top-gated p-FET with a subthreshold swing of 64 mV per decade at 290 K.
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This work was supported by the National Science Foundation through a CAREER Award (ECCS-1752401) and by the Center for Precision Assembly of Superstratic and Superatomic Solids (DMR-1420634). This work is also supported by the National Research Foundation of Korea through the Global Research Laboratory (GRL) program (2016K1A1A2912707) and Research Fellow program (2018R1A6A3A11045864).
Supplementary Figs. 1–11.