The Effects of Fluoropolymer Gate-Dielectric on the Air Stability of MoS2 Field-Effect Transistors

Abstract

We report the improved hysteresis and air stability of multilayer MoS2 FETs fabricated on a fluoropolymer CYTOP gate-dielectric layer. The fabricated devices, in comparison to the devices on a cross-linked Poly(4-vinylphenol) [PVP] layer, exhibit less hysteretic behavior in ambient as well as vacuum conditions and thus smaller hysteresis gap. Furthermore, the amount of threshold voltage shifts (Delta V-TH) over two months in the shelf is also reduced (0.6 +/- 1.2 V) compared to the devices on the PVP layer (-2.0 +/- 0.4 V). These improvements are attributed to less charge trapping effect by adsorbed oxygen and/or water molecules on the surface due to hydrophobic fluorine group, indicating the fluoropolymer gate-dielectric can be a good candidate for flexible low-power electronics with improved stability.