NUK - logo
E-resources
Full text
Peer reviewed
  • Clean Interface Contact Usi...
    Jang, Jisu; Kim, Yunseob; Chee, Sang-Soo; Kim, Hanul; Whang, Dongmok; Kim, Gil-Ho; Yun, Sun Jin

    ACS applied materials & interfaces, 01/2020, Volume: 12, Issue: 4
    Journal Article

    Two-dimensional transition metal dichalcogenides (TMDCs) have emerged as promising materials for next-generation electronics due to their excellent semiconducting properties. However, high contact resistance at the metal–TMDC interface plagues the realization of high-performance devices. Here, an effective metal–interlayer–semiconductor (MIS) contact is demonstrated, wherein an ultrathin ZnO interlayer is inserted between the metal electrode and MoS2, providing damage-free and clean interfaces at electrical contacts. Using TEM imaging, we show that the contact interfaces were atomically clean without any apparent damages. Compared to conventional Ti/MoS2 contacts, the MoS2 devices with a Ti/ZnO/MoS2 contact exhibit a very low contact resistance of 0.9 kΩ μm. These improvements are attributed to the following mechanisms: (a) Fermi-level depinning at the metal/MoS2 interface by reducing interface disorder and (b) presence of interface dipole at the metal/ZnO interface, consequently reducing the Schottky barrier and contact resistance. Further, the contact resistivity of a Ti/ZnO/MoS2 contact is insensitive to the variation of ZnO thickness, which facilitates large-scale production. Our work not only elucidates the underlying mechanisms for the operation of the MIS contact but also provides a simple and damage-free strategy for conventional aggressive metal deposition that is potentially useful for the realization of large-scale 2D electronics with low-resistance contacts.