Hafnium-doped zirconia ferroelectric thin films with excellent endurance at high polarization. Issue 3 (3rd January 2023)

• Record Type: Journal Article
• Authors: Cao, Yating; Zhang, Wei; Li, Yubao
• Is Part Of: Nanoscale. Volume 15:Issue 3(2023)
• Page Start: 1392
• Page End: 1401
• Publication Date: 2023-01-03
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/d2nr05678j
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : ZHO (3 : 1) thin film, prepared by thermal ALD and postdeposition annealing, exhibits a giant polarization of 41 μC cm −2 in a 10 nm film and outstanding endurance, holding up for over 10 9 cycles at 27 μC cm −2 and for up to 1 × 10 7 cycles at 41 μC cm −2 . Abstract : Using thermal atomic layer deposition and subsequent rapid thermal annealing without the need for metal clamping atop, a remanent polarization ( P r ) of 25.5 μC cm −2 was achieved in a 10 nm-thick ZrO2 film deposited on a W bottom electrode. Hafnium doping was further explored to improve the ferroelectric properties in P r as well as the endurance of zirconia-based thin films. A significantly enhanced P r reaching 41 μC cm −2 was obtained for 10 nm-thick hafnium-doped ZrO2 with an optimal Zr : Hf ratio of 3 : 1. Importantly, owing to the greatly reduced leakage, the optimal hafnium-doped ZrO2 thin films exhibited superior retention and outstanding endurance performances at relatively high polarizations, free of serious degradation for up to 2.3 × 10 9 –6.8 × 10 9 field cycles at an initial P r of 27 μC cm −2 and were even capable of over 10 7 cycles at a maximum P r of 41 μC cm −2 . The superb ferroelectricities were demonstrated on big-sized capacitors as well as sub-micrometer ones, isolated or in array. This would empower zirconia-based ferroelectric thin films as a competitive front-runner for practical applications in ferroelectric-related nanoelectronics.