First demonstration of vertically stacked ferroelectric Al doped HfO&lt;inf&gt;2&lt;/inf&gt; devices for NAND applications

Florent, Karine; Lavizzari, S.; Piazza, Luca; Popovici, M.; Vecchio, E.; Potoms, Goedele; Groeseneken, G.; IHoudt, J. Van

doi:10.23919/vlsit.2017.7998162

Cited by 59 publications

(37 citation statements)

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“…In general, this peak could be ascribed to the mixed phases of cubic, tetragonal, and orthorhombic in HfO 2 thin films. However, because of their similar lattice parameters, it is difficult to unambiguously and quantitatively identify these phases. − Among these phases, the orthorhombic phase is considered to be the cause of ferroelectricity. − Particularly, during thermal annealing process, the ferroelectric orthorhombic phase could be stabilized or promoted in HfO 2 -based films, and this process normally requires high crystallization temperature. For HZO films, annealing at ∼500 °C is required to achieve feasible ferroelectricity .…”

Section: Resultsmentioning

confidence: 99%

Thermally Stable and Radiation Hard Ferroelectric Hf_0.5Zr_0.5O₂ Thin Films on Muscovite Mica for Flexible Nonvolatile Memory Applications

Xiao

Liu

Peng

et al. 2019

ACS Appl. Electron. Mater.

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Metal–ferroelectric–metal (MFM) capacitors on flexible substrates are promising for flexible nonvolatile memory applications, while the insufficient scalability of perovskite-based ferroelectric thin films and the difficulty of direct integration of high performance ferroelectric thin films on current conventional flexible substrates are the most serious obstacles to their practical applications. Meanwhile, performance under harsh conditions (such as high temperature and high total ionized dose (TID) radiation) is highly demanded due to the growing applications for nonvolatile memory. Here, we integrate highly scalable ferroelectric Hf0.5Zr0.5O2 (HZO) thin films on potential flexible mica substrates using atomic layer deposition (ALD) to form flexible MFM capacitors and investigate the ferroelectric properties, the retention behaviors, and endurance characteristics of the TaN/HZO/TaN/mica flexible MFM capacitors under various tensile and compressive bending radii. In addition, these characteristics of the HZO-based MFM flexible capacitors are explored in a wide temperature range from 25 up to 125 °C. The ferroelectricity of the film can be retained under a bending radius down to 7.5 mm after 1000 bending cycles, and the retention properties can be reserved under a bake time of 104 s at 125 °C, with an extrapolated retention time-to-failure longer than 10 years. Furthermore, the flexible devices display robust ferroelectric performance against radiation of 60Co γ-rays with a total dose of 1 Mrad (Si). Our work represents a critical step in HfO2-based ferroelectric memory implemented on mica toward flexible nonvolatile memory operated under harsh conditions.

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Section: Resultsmentioning

confidence: 99%

Thermally Stable and Radiation Hard Ferroelectric Hf_0.5Zr_0.5O₂ Thin Films on Muscovite Mica for Flexible Nonvolatile Memory Applications

Xiao

Liu

Peng

et al. 2019

ACS Appl. Electron. Mater.

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“…As shown in Supplementary Table 1, the 1T1C FeRAM requires a large capacitor area ("footprint") and undergoes destructive readout. FeFET can realize non-distructive read and 3D vertical stack [9][10][11] . However, it cannot be used as a random-access memory.…”

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confidence: 99%

A highly CMOS compatible hafnia-based ferroelectric diode

et al. 2020

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Memory devices with high speed and high density are highly desired to address the 'memory wall' issue. Here we demonstrated a highly scalable, three-dimensional stackable ferroelectric diode, with its rectifying polarity modulated by the polarization reversal of Hf 0.5 Zr 0.5 O 2 films. By visualizing the hafnium/zirconium lattice order and oxygen lattice order with atomicresolution spherical aberration-corrected STEM, we revealed the correlation between the spontaneous polarization of Hf 0.5 Zr 0.5 O 2 film and the displacement of oxygen atom, thus unambiguously identified the non-centrosymmetric Pca2 1 orthorhombic phase in Hf 0.5 Zr 0.5 O 2 film. We further implemented this ferroelectric diode in an 8 layers 3D array. Operation speed as high as 20 ns and robust endurance of more than 10 9 were demonstrated. The builtin nonlinearity of more than 100 guarantees its self-selective property that eliminates the need for external selectors to suppress the leakage current in large array. This work opens up new opportunities for future memory hierarchy evolution.

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“…Ferroelectric (FE) doped-hafnia (HfO 2 ) holds promise as a lead-free material to reignite integrated ferroelectrics, enabling low-power, high-density non-volatile memory, and integrated sensors [1]. This has yielded a growing interest from both academic and industrial communities exploring theoretical and practical aspects of FE-HfO 2 , with demonstrations of scaled ferroelectric field effect transistors (FeFET) and random access memory (FeRAM), in planar and vertical architectures [2][3][4][5][6]. More generally, hafnia is one of the most studied binary oxide systems, it is compatible with existing complementary metal-oxide-semiconductor (CMOS) process technologies and is widely used as a gate dielectric in transistors.…”

Section: Introductionmentioning

confidence: 99%

Ferroelectricity in Si-Doped Hafnia: Probing Challenges in Absence of Screening Charges

et al. 2020

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The ability to develop ferroelectric materials using binary oxides is critical to enable novel low-power, high-density non-volatile memory and fast switching logic. The discovery of ferroelectricity in hafnia-based thin films, has focused the hopes of the community on this class of materials to overcome the existing problems of perovskite-based integrated ferroelectrics. However, both the control of ferroelectricity in doped-HfO2 and the direct characterization at the nanoscale of ferroelectric phenomena, are increasingly difficult to achieve. The main limitations are imposed by the inherent intertwining of ferroelectric and dielectric properties, the role of strain, interfaces and electric field-mediated phase, and polarization changes. In this work, using Si-doped HfO2 as a material system, we performed a correlative study with four scanning probe techniques for the local sensing of intrinsic ferroelectricity on the oxide surface. Putting each technique in perspective, we demonstrated that different origins of spatially resolved contrast can be obtained, thus highlighting possible crosstalk not originated by a genuine ferroelectric response. By leveraging the strength of each method, we showed how intrinsic processes in ultrathin dielectrics, i.e., electronic leakage, existence and generation of energy states, charge trapping (de-trapping) phenomena, and electrochemical effects, can influence the sensed response. We then proceeded to initiate hysteresis loops by means of tip-induced spectroscopic cycling (i.e., “wake-up”), thus observing the onset of oxide degradation processes associated with this step. Finally, direct piezoelectric effects were studied using the high pressure resulting from the probe’s confinement, noticing the absence of a net time-invariant piezo-generated charge. Our results are critical in providing a general framework of interpretation for multiple nanoscale processes impacting ferroelectricity in doped-hafnia and strategies for sensing it.

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First demonstration of vertically stacked ferroelectric Al doped HfO<inf>2</inf> devices for NAND applications

Cited by 59 publications

References 0 publications

Thermally Stable and Radiation Hard Ferroelectric Hf_0.5Zr_0.5O₂ Thin Films on Muscovite Mica for Flexible Nonvolatile Memory Applications

Thermally Stable and Radiation Hard Ferroelectric Hf_0.5Zr_0.5O₂ Thin Films on Muscovite Mica for Flexible Nonvolatile Memory Applications

A highly CMOS compatible hafnia-based ferroelectric diode

Ferroelectricity in Si-Doped Hafnia: Probing Challenges in Absence of Screening Charges

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First demonstration of vertically stacked ferroelectric Al doped HfO<inf>2</inf> devices for NAND applications

Cited by 59 publications

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Thermally Stable and Radiation Hard Ferroelectric Hf0.5Zr0.5O2 Thin Films on Muscovite Mica for Flexible Nonvolatile Memory Applications

Thermally Stable and Radiation Hard Ferroelectric Hf0.5Zr0.5O2 Thin Films on Muscovite Mica for Flexible Nonvolatile Memory Applications

A highly CMOS compatible hafnia-based ferroelectric diode

Ferroelectricity in Si-Doped Hafnia: Probing Challenges in Absence of Screening Charges

Contact Info

Product

Resources

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Thermally Stable and Radiation Hard Ferroelectric Hf_0.5Zr_0.5O₂ Thin Films on Muscovite Mica for Flexible Nonvolatile Memory Applications

Thermally Stable and Radiation Hard Ferroelectric Hf_0.5Zr_0.5O₂ Thin Films on Muscovite Mica for Flexible Nonvolatile Memory Applications