Significant Reliability Improvement by Inducing Dual Atomic-Thin Titanium Intercalation Layers in Hf<sub>0.5</sub>Zr<sub>0.5</sub>O<sub>2</sub> Films
Lu Tai, Wei Wei, Pengpeng Sang, Xiaopeng Li, Guoqing Zhao, Pengfei Jiang, Peng Yuan, Qing Luo, Xuepeng Zhan, Jixuan Wu, Jiezhi Chen
Abstract
This work studies the ferroelectric Hf <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{{0}.{5}}$ </tex-math></inline-formula> Zr0.5O2 (HZO) thin film with various designs of intercalation layers. Among the studied intercalation stacks, HZO films with dual <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim $ </tex-math></inline-formula> 0.05 nm titanium layers (DL-Ti) present ultrahigh remanent polarization ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2{P}_{{\text {r}}}\sim 57 \mu \text{C}$ </tex-math></inline-formula> /cm2), a low coercive field ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${E}_{{\text {c}}}\sim 1.1$ </tex-math></inline-formula> MV/cm), and a high breakdown field ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${E}_{{\text {BD}}}\sim 4.3$ </tex-math></inline-formula> MV/cm). Wherein, a rather low <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${E}_{{\text {c}}}/{E}_{{\text {BD}}}$ </tex-math></inline-formula> of 27% can greatly benefit endurance property. In comparison to the standard HZO films, 3 orders better endurance ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{{10}}$ </tex-math></inline-formula> cycles @3 MV/cm) has been achieved in DL-Ti HZO films, while only 3% <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${P}_{{\text {r}}}$ </tex-math></inline-formula> degradation can be observed even after <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{{7}}$ </tex-math></inline-formula> cycles (@125 °C). Our results strongly indicate that atomic layer doping is an effective approach to engineer HZO-based devices with better performance and robust reliabilities.