Superlattice HfO<sub>2</sub>-ZrO<sub>2</sub> based Ferro-Stack HfZrO<sub>2</sub> FeFETs: Homogeneous-Domain Merits Ultra-Low Error, Low Programming Voltage 4 V and Robust Endurance 10<sup>9</sup> cycles for Multibit NVM
C.-Y. Liao, Zhonghao Lou, Chin‐An Lin, A. Senapati, Rajdip Karmakar, K.-Y. Hsiang, Z.-X. Li, W.-C. Ray, Jia-Yang Lee, Ping‐Hung Chen, F.-S. Chang, Hsin-Chun Tseng, C.-C. Wang, Jeng‐Han Tsai, Y.-T. Tang, S. T. Chang, C. W. Liu, S. Maikap, M. H. Lee
Abstract
Superlattice (SL) HfO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> -ZrO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> with physical thickness of 5 nm and low phase fraction ratio 0.101:1 of monoclinic-phase (m-phase) to orthorhombic-phase (o-phase) investigated by geometrical phase analysis (GPA) is demonstrated. The homogeneous and congruous of SL-HfZrO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> (HZO) with sufficient ferroelectric-domain is integrated as ferro-stack FeFETs for multibit NVM with low |V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PG/ER</inf> | = 4 V, ultra-low error rate = 7.5×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-16</sup> , record high 2-bit endurance for 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">9</sup> cycles, and stable data retention > 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> s. The device-to-device (D2D) variation of nanoscale 3D FeFETs is also improved with the proposed SL-HZO. The superlattice technique for FE-HZO is a promising concept with elevating the coherence of domain access due to high o-phase toward emerging memory applications.