High-performance MoS2 field-effect transistors enabled by chloride doping: Record low contact resistance (0.5 kΩ·µm) and record high drain current (460 µA/µm)

• Published in: 2014 Symposium on VLSI Technology (VLSI-Technology): Digest of Technical Papers pp. 1 - 2
• Main Authors: Lingming Yang, Majumdar, Kausik, Yuchen Du, Han Liu, Heng Wu, Hatzistergos, Michael, Hung, P. Y., Tieckelmann, Robert, Tsai, Wilman, Hobbs, Chris, Ye, Peide D.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.06.2014
• Subjects: Doping; Field effect transistors; Gold; Logic gates; Nickel; Time-domain analysis; Time-varying systems
• ISBN: 9781479933310; 1479933317
• ISSN: 0743-1562
• DOI: 10.1109/VLSIT.2014.6894432

In this paper, we report a novel chemical doping technique to reduce the contact resistance (R c ) of transition metal dichalcogenides (TMDs) - eliminating two major roadblocks (namely, doping and high R c ) towards demonstration of high-performance TMDs field-effect transistors (FETs). By using 1,2 dichloroethane (DCE) as the doping reagent, we demonstrate an active n-type doping density > 2×10 19 cm -3 in a few-layer MoS 2 film. This enabled us to reduce the R c value to a record low number of 0.5 kΩ·μm, which is ~10×lower than the control sample without doping. The corresponding specific contact resistivity (ρ c ) is found to decrease by two orders of magnitude. With such low R c , we demonstrate 100 nm channel length (L ch ) MoS 2 FET with a drain current (I ds ) of 460 μA/μm at V ds = 1.6 V, which is twice the best value reported so far on MoS 2 FETs.