Improved ferroelectric properties of CMOS back-end-of-line compatible Hf0.5Zr0.5O2 thin films by introducing dielectric layers

Improved Ferroelectricity and Tunneling Electroresistance by Inducing the ZrO2 Intercalation Layer in La:HfO2 Thin Films

“…When a voltage lower than the coercive voltage ( V c ) of the ferroelectric stack is applied to the electrodes, the current associated with polarization can be nondestructively measured. In order to obtain a reasonable current difference between the ON and OFF states and achieve a high TER, defined as TER = ( I LRS – I HRS )/ I HRS where I LRS and I HRS are the current level as the low-resistance state and high-resistance state, respectively, the FTJ devices must be formed by asymmetric stack layers, in which the TER effect refers to the reversible change in tunneling conductivity through a thin ferroelectric barrier layer induced by the polarization switching of the ferroelectric material. − It has been established that the TER effect correlates with variations in the effective potential barrier, attributed to asymmetric charge screening length at the barrier/electrode interface and the ferroelectric polarization induced built-in polarization field. − It can be seen that researchers commonly introduce interfacial layers, such as TiO 2 , , HfO 2 , , Al 2 O 3 , , and ZrO 2 , between the electrodes and the Zr:HfO 2 ferroelectric layer for studying the FTJ performance. For instance, Max et al proposed a bilayer FTJ structure consisting of hafnium zirconium oxide (HZO) as the ferroelectric layer and aluminum oxide (Al 2 O 3 ) as the tunneling barrier.…”

Perspectives of Ferroelectric Wurtzite AlScN: Material Characteristics, Preparation, and Applications in Advanced Memory Devices

“…Additionally, the inclusion of lead-based toxic materials, such as PZT, poses significant environmental challenges [ 18 , 19 ]. The fluorite structure seems to exhibit high scalability and perfect compatibility with CMOS processes [ 20 ]. However, the stability issues arising from polycrystalline and multiphase structures hinder their ability to ensure reliable data storage capabilities after multiple cycles [ 21 , 22 ].…”