Ultra-High-kFerroelectric BaTiO3Perovskite in the Gate Stack for Two-Dimensional WSe2p-Type High-Performance Transistors

The experimental demonstration of a p-type 2D WSe2transistor with a ferroelectric perovskite BaTiO3gate oxide is presented. The 30 nm thick BaTiO3gate stack shows a robust ferroelectric hysteresis with a remanent polarization of 20 μC/cm2and further enables a capacitance equivalent thickness of 0.5 nm in the hybrid WSe2/BaTiO3stack due to its high dielectric constant of 323. We demonstrate one of the best ON currents for perovskite gate 2D transistors in the literature. This is enabled by high-quality epitaxial growth of BaTiO3and a single 2D layer transfer based fabrication method that is shown to be amenable to silicon platforms. This demonstration is an important milestone toward the integration of crystalline complex oxides with 2D channel materials for scaled CMOS and low-voltage ferroelectric logic applications.