Deep electron traps in HfO2-based metal-oxide-semiconductor capacitors

Salomone, L. Sambuco; Lipovetzky, J.; Carbonetto, S.; Inza, M. A. García; Redin, E.; Campabadal, F.; Faigon, A.

doi:10.1016/j.tsf.2016.01.007

Cited by 6 publications

(7 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Such trap states are introduced by the and 68 – 76 , and therefore, their contribution to the hysteresis could change with the applied voltage, composition, and microstructure 76 , 77 . Electron trap states have been analyzed in other Al 2 O 3 /HfO 2 structures, which were designed as charge-trapping memories with retention times of up to s 78 – 80 . Such a mechanism could contribute to the hysteresis curves in our devices, too.…”

Section: Resultsmentioning

confidence: 99%

Multilayer redox-based HfOx/Al2O3/TiO2 memristive structures for neuromorphic computing

Park

Spetzler

Ivanov

et al. 2022

Sci Rep

View full text Add to dashboard Cite

Redox-based memristive devices have shown great potential for application in neuromorphic computing systems. However, the demands on the device characteristics depend on the implemented computational scheme and unifying the desired properties in one stable device is still challenging. Understanding how and to what extend the device characteristics can be tuned and stabilized is crucial for developing application specific designs. Here, we present memristive devices with a functional trilayer of HfOx/Al2O3/TiO2 tailored by the stoichiometry of HfOx (x = 1.8, 2) and the operating conditions. The device properties are experimentally analyzed, and a physics-based device model is developed to provide a microscopic interpretation and explain the role of the Al2O3 layer for a stable performance. Our results demonstrate that the resistive switching mechanism can be tuned from area type to filament type in the same device, which is well explained by the model: the Al2O3 layer stabilizes the area-type switching mechanism by controlling the formation of oxygen vacancies at the Al2O3/HfOx interface with an estimated formation energy of ≈ 1.65 ± 0.05 eV. Such stabilized area-type devices combine multi-level analog switching, linear resistance change, and long retention times (≈ 107–108 s) without external current compliance and initial electroforming cycles. This combination is a significant improvement compared to previous bilayer devices and makes the devices potentially interesting for future integration into memristive circuits for neuromorphic applications.

show abstract

Section: Resultsmentioning

confidence: 99%

Multilayer redox-based HfOx/Al2O3/TiO2 memristive structures for neuromorphic computing

Park

Spetzler

Ivanov

et al. 2022

Sci Rep

View full text Add to dashboard Cite

show abstract

“…This experimental finding suggests that an electronic current starts to circulate with a consequent reduction of the growth efficiency according to Eq. 2. holds: 38,39 (Q ph hν) n ∝ (hν−E g opt ) [ 4 ] in which Q ph , the photocurrent yield, is proportional to the light absorption coefficient and hν is the photon energy. According to Eq.…”

Section: Resultsmentioning

confidence: 99%

“…In recent years, intense research has been carried out on HfO 2 as high dielectric constant material, a promising candidate to replace SiO 2 as a gate dielectric in CMOS based devices, [1][2][3][4] and as metal oxide for resistive random access memory (ReRAM). [5][6][7] This interest arises because hafnium oxide combines a large band-gap (E g = 5.1 -6.1 eV), [8][9][10][11][12][13] a dielectric permittivity (ε = 16-25) 1,13 significantly higher than that of silicon oxide (∼4), high thermal stability and high thermodynamic stability in contact with silicon.…”

mentioning

confidence: 99%

The Effect of Nb Incorporation on the Electronic Properties of Anodic HfO₂

Zaffora

Franco

Quarto

et al. 2017

ECS J. Solid State Sci. Technol.

View full text Add to dashboard Cite

Hafnium oxide and Nb doped HfO2 were grown by anodizing sputtering-deposited Hf and Hf-4at.%Nb. Photoelectrochemical characterization was carried out in order to estimate solid state properties such as band gap, flat band potential and electrons internal photoemission threshold energy as a function of thickness and composition of anodic oxides. Optical transitions at energy lower than the band gap value of the investigated anodic films were evidenced, and they are attributed to optical transitions involving localized states inside the band gap. Such states were located at 3.6 eV and 3.9 eV below the conduction band edge for the Nb free and Nb containing hafnium oxide, respectively. Impedance measurements were performed in a wide range of electrode potentials under anodic and cathodic polarization with respect to the flat band potential, confirming the formation of insulating oxides with high dielectric constant. The latter increases from 20 to 41 due to incorporation of Nb into the oxide

show abstract

“…Thus, it is very crucial to study an encouraging prospective material to replace the Si based gate oxides. In that respect, HfO 2 is a favorite high-k material [3][4][5][6] to be studied for the development of MOS devices because of its wide band gap (E g >5 eV) [7], a high-κ dielectric constant (κ=25) [8] and thermal stability on Si [9].…”

Section: Introductionmentioning

confidence: 99%

Comparision of in situ spectroscopic ellipsometer and ex situ x-ray photoelectron spectroscopy depth profiling analysis of HfO₂/Hf/Si multilayer structure

Cantaş

Özyüzer

Aygün

2018

Mater. Res. Express

View full text Add to dashboard Cite

A HfO 2 film was grown by RF magnetron sputtering technique on a Si substrate Using in situ Spectroscopic Ellipsometry (SE), the film thickness and refractive index were examined as a function of deposition time. Ex situ x-ray Photoelectron Spectroscopy (XPS) was used in depth profile mode to determine the phase evolution of HfO 2 /Hf/Si multilayer structure after the growth process. The chemical composition and the crystal structure of the film were investigated by Fourier Transform Infrared (FTIR) spectroscopic measurements and x-ray Diffraction in Grazing Incidence (GI-XRD) mode, respectively. The results showed that the film was grown in the form of HfO 2 film. According to SE analysis, reactive deposition of HfO 2 directly on Hf/Si results to SiO 2 interface of about 2 nm. The final HfO 2 films thickness is 5.4 nm. After a certain period of time, the XPS depth profile revealed that the film was in the form of Hf-rich Hf silicate with SiO 2 interfacial layer. In reference to XPS quantification analysis from top to bottom of film, the atomic concentration of Hf element reduces from 19.35% to 7.13%, whereas Si concentration increases from 22.99% to 74.89%. The phase change of HfO 2 film with time is discussed in details. RECEIVED

show abstract

Deep electron traps in HfO2-based metal-oxide-semiconductor capacitors

Cited by 6 publications

References 46 publications

Multilayer redox-based HfOx/Al2O3/TiO2 memristive structures for neuromorphic computing

Multilayer redox-based HfOx/Al2O3/TiO2 memristive structures for neuromorphic computing

The Effect of Nb Incorporation on the Electronic Properties of Anodic HfO₂

Comparision of in situ spectroscopic ellipsometer and ex situ x-ray photoelectron spectroscopy depth profiling analysis of HfO₂/Hf/Si multilayer structure

Contact Info

Product

Resources

About

Deep electron traps in HfO2-based metal-oxide-semiconductor capacitors

Cited by 6 publications

References 46 publications

Multilayer redox-based HfOx/Al2O3/TiO2 memristive structures for neuromorphic computing

Multilayer redox-based HfOx/Al2O3/TiO2 memristive structures for neuromorphic computing

The Effect of Nb Incorporation on the Electronic Properties of Anodic HfO2

Comparision of in situ spectroscopic ellipsometer and ex situ x-ray photoelectron spectroscopy depth profiling analysis of HfO2/Hf/Si multilayer structure

Contact Info

Product

Resources

About

The Effect of Nb Incorporation on the Electronic Properties of Anodic HfO₂

Comparision of in situ spectroscopic ellipsometer and ex situ x-ray photoelectron spectroscopy depth profiling analysis of HfO₂/Hf/Si multilayer structure