Controllable Polarization Switching of Hafnia-Based Ferroelectric Bilayers

For neuromorphic applications, achieving a precisely controllable remnant polarization (P
r
) as well as coercive voltage (V
C
) is crucial to achieve a multilevel polarization in the ferroelectric layer (FL). Therefore, we introduce bilayered ferroelectric thin films with Zr-doped HfO
2
(HZO) on top of Al-doped HfO
2
(HAO), allowing the adjustment of P
r
over a broad voltage range relative to the ramping voltage. In the bilayer ferroelectric HZO/HAO, polarization switching behavior occurs sequentially through each FL, which results in tunable P
r
characteristics.