Controllable Oxidation of ZrS 2 to Prepare High-κ, Single-crystal m-ZrO 2 for 2D Electronics.

High-κ materials that exhibit large permittivity and band gaps are needed as gate dielectrics to enhance capacitance and prevent leakage current in downsized technology nodes. Among these, monoclinic ZrO 2 (m-ZrO 2 ) shows good potential because of its inertness and high-κ with respect to SiO 2 , but a method to produce ultrathin single crystal is lacking. Here, the controllable preparation of ultrathin m-ZrO 2 single crystals via the in situ thermal oxidation of ZrS 2 is achieved. As-grown m-ZrO 2 presents an equivalent oxide thickness of ≈0.29 nm, a high dielectric constant of ≈19, and a breakdown voltage (E BD ) of ≈7.22 MV cm -1 . MoS 2 field effect transistor (FET) by using m-ZrO 2 as a dielectric layer shows comparable mobility to that using SiO 2 dielectric. The ultraclean interface of m-ZrO 2 /MoS 2 and high crystalline quality of m-ZrO 2 lead to negligible hysteresis in transfer curves. Single crystal m-ZrO 2 dielectric shows potential application in digital complementary metal oxidesemiconductor (CMOS) logic FET.