Controlling the Ferroelectricity of Doped-HfO<sub>2</sub> via Reversible Migration of Oxygen Vacancy
Jiajia Chen, Jiacheng Xu, Zhi Gong, Jiani Gu, Xiao Yu, Chengji Jin, Yue Peng, Yan Liu, Bing Chen, Ran Cheng, Genquan Han
Abstract
We have experimentally demonstrated that the ferroelectricity can be controlled by reversibly injecting oxygen vacancies ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {o}}{)}$ </tex-math></inline-formula> from the interfacial layer (IL) of TiOxNy to 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) or extracting them from HZO to IL in the titanium nitride (TiN) <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$/$ </tex-math></inline-formula> HZO <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$/$ </tex-math></inline-formula> TiN structure for the first time. The IL between the TiN electrode and HZO thin film plays a crucial role as the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {o}}$ </tex-math></inline-formula> reservoir. By adjusting the electrical pre-stress time to modulate the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {o}}$ </tex-math></inline-formula> concentration and distribution, HZO shows multiferroelectricity which can be switchable. In addition, the experimental multiferroelectricity can be correctly reproduced by the simulation with a phase-field polarization switching model. The simulated results herein strongly support the mechanism that modulating the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {o}}$ </tex-math></inline-formula> migration reversibly from IL into HZO can achieve multiferroelectricity control.