Impact of Pre-Annealed ZrO 2 Interfacial Layer on the Ferroelectric Behavior of Hf 0.5 Zr 0.5 O 2.

This work systematically investigates the impact of a pre-annealed ZrO₂ interfacial layer on the ferroelectric behavior of Hf_0.5Zr0.₅O₂ (HZO) capacitors. The remanent polarization (2Pr) value of HZO capacitors, including configurations such as W/HZO/TiN/p⁺ Si, W/HZO/(pre-annealed) ZrO₂/TiN/p⁺ Si, W/HZO/SiO₂/TiN/p⁺ Si, and W/HZO/SiO₂/p⁺ Si, exhibits significant variations. The W/HZO/(pre-annealed) ZrO₂/TiN/p⁺ Si capacitor demonstrates superior ferroelectric performance, with a 2Pr value of ~32 µC/cm². Furthermore, by optimizing the thickness combination of HZO and the pre-annealed ZrO₂ interfacial layer, a capacitor with a 10 nm HZO and 2 nm ZrO₂ achieves the largest 2Pr value. The pre-annealing process applied to ZrO₂ is found to play a very important role in inducing the orthorhombic phase and thus enhancing ferroelectricity. This enhancement is attributed to the pre-annealed 2 nm ZrO₂ interfacial layer acting as a structural guide for the subsequent HZO orthorhombic phase, thereby improving the ferroelectric performance of HZO capacitors. These findings provide a comprehensive explanation and experimental verification of the impact of pre-annealed ZrO₂ on ferroelectric devices, offering novel insights for the optimization of ferroelectric properties. [ABSTRACT FROM AUTHOR]