LAUSR

Achieving excellent electrostatic control and immunity to short channel effects are the formidable challenges in ultrascaled devices. 3D device architectures, such as nanoribbon, have successfully mitigated these problems by achieving uniform topand side-wall control of the channel. Here, by leveraging on the merits of 3D structure, high-mobility black phosphorus nanoribbon fieldeffect transistors (BPNR-FET) are demonstrated and the anisotropic transport properties are systematically investigated. A simple top-down reactive ion etching method is used to realize both armchairand zigzag-oriented nanoribbons with various widths down to 60 nm. The mobility of BPNR-FET is found to be widthand thickness-dependent, with the highest hole mobility of ≈862 cm2 V−1 s−1 demonstrated in armchair-oriented device at room temperature by combining high-κ gate dielectric and hydrogen treatment to reduce sidewall scattering. Furthermore, hydrogenation effectively passivates the nanoribbon dangling bonds, leading to hysteresis and contact resistance improvement. This work unravels the superior electrical performance underscore a conceptually new device based on BP nanoribbons, paving the way toward the development of nonplanar devices on 2D materials platform.