Fig. 6: High-performance NO-Doped 2L-WSe2 FETs with ultralow contact resistance.
From: Uncovering the doping mechanism of nitric oxide in high-performance P-type WSe2 transistors
a Schematic of a 2D FET with a bilayer WSe2 channel after NO doping. b A cross-sectional scanning transmission electron microscopy (STEM) image of a representative short-channel bilayer WSe2 transistor, featuring a 3.5 nm HfO2 dielectric, 0.5/20/20 nm Ti/Pt/Au metal contacts, and a channel length of 55 nm. c Raman spectra of bilayer WSe2 before and after NO treatment at 130 °C for 1 h d linear-scale and e log-scale ID-VG at VD = –1V of representative devices with LCH = 55 nm, both before (black) and NO doping at different steps. f ID-VD of a short channel (LCH = 55 nm) NO-doped 2L-WSe2 p-FET. The black line represents the total resistance (RTOT) of this representative short-channel device. g Schematic of the energy band diagram of the semiconductor-dielectric interface, where the doping band starts approaching the Fermi-window when increasing the doping temperature and time duration. Defect bands (blue for acceptor-like traps and red for donor-like traps) are displayed in the gate dielectric and Fermi window (gray) within the semiconductor channel. h Total resistance as a function of channel length (LCH) at VOV = -1V for two TLM sets. Total resistance (RTOT) is extracted at VDS = -0.1 V.
