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Field‐Induced Ferroelectric Hf 1‐ x Zr x O 2 Thin Films for High‐ k Dynamic Random Access Memory
Author(s) -
Hyun Seung Dam,
Park Hyeon Woo,
Park Min Hyuk,
Lee Young Hwan,
Lee Yong Bin,
Kim Beom Yong,
Kim Ho Hyun,
Kim Baek Su,
Hwang Cheol Seong
Publication year - 2020
Publication title -
advanced electronic materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.25
H-Index - 56
ISSN - 2199-160X
DOI - 10.1002/aelm.202000631
Subject(s) - materials science , permittivity , dielectric , ferroelectricity , electric field , dram , thin film , hysteresis , condensed matter physics , annealing (glass) , high κ dielectric , polarization (electrochemistry) , analytical chemistry (journal) , optoelectronics , composite material , nanotechnology , chemistry , physics , quantum mechanics , chromatography
The field‐induced ferroelectric Hf 1– x Zr x O 2 (FFE–HZO) thin film is investigated for use as the capacitive layer in the future dynamic random access memory (DRAM). Although the dielectric permittivity of FFE–HZO is as high as ≈80, a high electric field (4 MV cm −1 ) is needed to activate the FFE mechanism and the accompanying high dielectric permittivity value. The Zr content is adjusted, or field cycling is performed, to obtain a high dielectric permittivity at a low electric‐field region for feasible DRAM operation. As a result, a dielectric permittivity value of 60–80 is achieved in the low field region (0–2 MV cm −1 ), which coincided with an equivalent oxide thickness of 0.47 nm with a stable leakage current at 0.8 V. The involvement of hysteresis in the polarization‐electric field curve of the film, however, caused significant energy loss (40–60%). Hysteresis engineering using various dopants, and improving the deposition process, annealing process, or passive interfacial layer, should be the next step.