Real-Time Polarization Switch Characterization of HfZrO4 for Negative Capacitance Field-Effect Transistor Applications

In this letter, the real-time polarization switching process in HfZrO
₄
ferroelectric film is investigated at high speed (100 MHz, highest up-to-date) by using the ultrafast measurements system. Based on the measurements over a wide range of speed from ms to ns, clear and detailed time-dependent behaviors of the polarization switch of HfZrO
₄
are captured. HfZrO
₄
film with 10 nm in thickness still exhibits ferroelectric characteristics measured with a voltage sweep period from 4 ms to 20 ns and a voltage amplitude of 4 V. The phenomenon of polarization switching diminishes distinctively with the increase of measurement speed. When the measurement speed reaches as fast as 10 ns, the polarization process could not be clearly observed. Therefore, high-speed application of negative capacitance field-effect transistor should be optimized to prevent potential problems caused by the insufficient polarization.