High-performance multilayer WSe2 field-effect transistors with carrier type control
transition metal dichalcogenide, field-effect transistors, carrier control, plasma treatment, carrier mobility
ABSTRACT In this study, high-performance multilayer WSe2 field-effect transistor (FET) devices with carrier type control are demonstrated via thickness modulation and a remote oxygen plasma surface treatment. Carrier type control in multilayer WSe2 FET devices with Cr/Au contacts is initially demonstrated by modulating the WSe2 thickness. The carrier type evolves with increasing WSe2 channel thickness, being p-type, ambipolar, and n-type at thicknesses 5 nm, respectively. The thickness-dependent carrier type is attributed to changes in the bandgap of WSe2 as a function of the thickness and the carrier band offsets relative to the metal contacts. Furthermore, we present a strong hole carrier doping effect via remote oxygen plasma treatment. It non-degenerately converts n-type characteristics into p-type and enhances field-effect hole mobility by three orders of magnitude. This work demonstrates progress towards the realization of high-performance multilayer WSe2 FETs with carrier type control, potentially extendable to other transition metal dichalcogenides, for future electronic and optoelectronic applications.
Tsinghua University Press
Pushpa Raj Pudasaini,Akinola Oyedele,Cheng Zhang,Michael G. Stanford,Nicholas Cross,Anthony T. Wong,Anna N. Hoffman,Kai Xiao,Gerd Duscher,David G. Mandrus,Thomas Z. Ward,Philip D. Rack, High-performance multilayer WSe2 field-effect transistors with carrier type control. NanoRes.2018, 11(2): 722–730