Temperature-Dependent Field Cycling Behavior of Ferroelectric Hafnium Zirconium Oxide (HZO) MFM Capacitors
Sourabh Jindal, S. K. Manhas, Simone Balatti, Arvind Kumar, Mahendra Pakala
Abstract
In this article, we study the field cycling behavior of ALD-deposited ferroelectric Hf <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub> Zr <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> with TiN as the top and bottom electrodes on the silicon substrate. We investigate the effect of temperature on the endurance, capacitance, and leakage of the device. We observe an insignificant wake-up effect attributed to the nitrogen-rich interface between TiN and HZO film. We also report an increase in the remnant polarization, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${P}_{r}$ </tex-math></inline-formula> , with temperature initially, and the reduced rate of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${P}_{r}$ </tex-math></inline-formula> degradation in the fatigue phase at elevated temperatures. The increase in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${P}_{r}$ </tex-math></inline-formula> of the devices at elevated temperatures is attributed to the strong de-pinning. The calculated trap barrier energy of 1 eV in the fatigue phase points toward oxygen vacancy generation in the film. The lower activation energy found in the fatigue phase suggests a higher de-pinning rate for the devices. The reduced rate of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${P}_{r}$ </tex-math></inline-formula> degradation in fatigue is attributed to two-competing mechanisms: vacancy generation (leading to domain pinning) and temperature-dependent de-pinning. The results presented in this study provide key insights into degradation mechanisms that are crucial for improving the reliability of HZO films.