Controllable Oxidation of ZrS2 to Prepare High-κ, Single-crystal m-ZrO2 for 2D Electronics

High-kappa materials that exhibit large permittivity and band gaps are needed as gate dielectrics to enhance capacitance and prevent leakage current in down-sized technology nodes. Among these, monoclinic ZrO2 (m-ZrO2) shows good potential because of its inertness and high-kappa with respect to SiO2, but a method to produce ultrathin single crystal is lacking. Here, the controllable preparation of ultrathin m-ZrO2 single crystals via the in situ thermal oxidation of ZrS2 is achieved. As-grown m-ZrO2 presents an equivalent oxide thickness of approximate to 0.29 nm, a high dielectric constant of approximate to 19, and a breakdown voltage (E-BD) of approximate to 7.22 MV cm(-1). MoS2 field effect transistor (FET) by using m-ZrO2 as a dielectric layer shows comparable mobility to that using SiO2 dielectric. The ultraclean interface of m-ZrO2/MoS2 and high crystalline quality of m-ZrO2 lead to negligible hysteresis in transfer curves. Single crystal m-ZrO2 dielectric shows potential application in digital complementary metal oxidesemi-conductor (CMOS) logic FET.