Doping dependent high-frequency dielectric properties of Hf1-xTixO2 nanoparticles

Pokhriyal, Sumit; Biswas, Somnath

doi:10.1016/j.matpr.2016.04.009

Cited by 14 publications

(9 citation statements)

References 31 publications

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“…HfO 2 is extremely attractive due to its high dielectric constant (ε r ~ 25), large band offset (∆E c ~ 1.5 eV) and chemical stability with silicon [4][5][6][7][8][9][10][11][12][13][14][15]. The present CMOS technology requires materials that are thermally stable at the temperatures over 800 °C in the case of gate dielectrics [16]. However, the drawback of HfO 2 is its low crystallization temperature of ca.…”

Section: Introductionmentioning

confidence: 99%

“…However, the drawback of HfO 2 is its low crystallization temperature of ca. 200 °C [17], resulting in a large leakage current, high oxygen and impurities penetration, and also defect generation which hinders its integration with traditional CMOS processes [5,6,14,[16][17][18][19][20][21][22]. Hafnium dioxide occurs in three polymorphs, including monoclinic, tetragonal and cubic phases [5,15,23].…”

Section: Introductionmentioning

confidence: 99%

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The effect of post-process annealing on optical and electrical properties of mixed HfO2–TiO2 thin film coatings

Obstarczyk

Kaczmarek

Mazur

et al. 2019

J Mater Sci: Mater Electron

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In this paper a comparison of electrical and optical properties of mixed hafnium-titanium oxides is described. Thin films were deposited with the use of the magnetron co-sputtering method. For further analysis (Hf 0.52 Ti 0.48)Ox and (Hf 0.29 Ti 0.71) Ox coatings, which were amorphous directly after the deposition process, were chosen,. Moreover, post-process annealing was also performed in order to compare the electrical and optical properties of amorphous and nanocrystalline thin films with the same material composition. It was found that the phase transition from amorphous to orthorhombic HfTiO 4 occurred in the case of (Hf 0.52 Ti 0.48)Ox coating at 650 °C. In turn, the phase transition to TiO 2-anatase was observed at the temperature of 600 °C in the case of (Hf 0.29 Ti 0.71)Ox thin film. The leakage current for both amorphous coatings was in the range of 10 −7-10 −8 A/cm 2. After additional annealing and phase transition, the leakage current slightly decreased for (Hf 0.29 Ti 0.71)Ox thin film, while in the case of (Hf 0.52 Ti 0.48)Ox sample the resistance switching effect was observed. The dielectric constant was equal to 24 and 25 for amorphous (Hf 0.52 Ti 0.48)Ox and (Hf 0.29 Ti 0.71)Ox films, respectively. However, after the phase transition it decreased to 15 for (Hf 0.52 Ti 0.48)Ox and increased to 51 for (Hf 0.29 Ti 0.71)Ox film. The results of optical studies showed that amorphous thin films were well transparent in a visible light range with an average transparency of ca. 85%. After the phase transition to HfTiO 4-orthorhombic and TiO 2-anatase, a slight decrease in the transparency level by 3% and a redshift of the cutoff wavelength was observed. Moreover, additional annealing caused small changes of the optical band gap energy, refractive index and extinction coefficient.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The effect of post-process annealing on optical and electrical properties of mixed HfO2–TiO2 thin film coatings

Obstarczyk

Kaczmarek

Mazur

et al. 2019

J Mater Sci: Mater Electron

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“…[36][37][38] Applied bias voltage evolution of the resistance was originated to the particle distribution of localized interface and interfacial hydrogels channels in the three-dimensional networks of polymer chains. 40,[54][55][56][57] The pit behavior in the electric modulus expressed that NPs loaded hydrogels capacitance shows the relaxation mechanism with the applied bias voltage. This relaxation mechanism can be related to the grains and grain boundaries.…”

Section: Discussionmentioning

confidence: 99%

“…This type potential effect can be observed by applied bias voltage dependence in detail. 40,54,55 The applied bias voltage evolutions of the resistance, the reactance and the impedance values with different amount NiFe 2 O 4 NPs loaded hydrogels are shown in the right column in Figs. 4d, 4e and 4f with respectively.…”

Section: N105mentioning

confidence: 99%

Optic and Dielectric Properties of Different Amount NiFe₂O₄Nanoparticles Loaded Hydrogels: Synthetic Circuits Applications

Okutan¹,

Coşkun²,

Öztürk³

et al. 2018

ECS J. Solid State Sci. Technol.

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Loaded hydrogels with different amount (2.5%, 5.0%, 7.5% and 10.0%) NiFe 2 O 4 nanoparticles have been prepared for elastic optoelectronic devices in nano size via the copolymerization technics. All samples have been characterized by the UV-Vis absorption spectroscopy. The resistance changes were analyzed by calculating from the slope of the current-voltage plots. The optical band gaps of the NiFe 2 O 4 nanoparticles loaded hydrogels decreases with increase of loading of nanoparticles amount. At room temperature (RT), frequency and applied bias voltage dependence of complex impedance, electric modulus, tangent factor and ionic conductivity have been studied with the impedance spectroscopy (IS). In addition, frequency and applied bias voltage of dependence on dielectric properties for NiFe 2 O 4 nanoparticles loaded hydrogels were compared with each other. Frequency evolution of the dielectric properties are drastically effected interface and electrode polarization. The lowest and highest values of the ε and ε were determined for 10% and 2.5% loaded NiFe 2 O 4 nanoparticles depend on applied bias voltage. The complex impedance based Cole-Cole diagrams and their adopted to Smith-Chart have been analyzed for synthetic equivalent resistance-capacitance circuits via frequency. The UV-Vis absorption values decreases and the conductivity values increases with increase because of increasing NiFe 2 O 4 nanoparticles amount and the grain size of loaded hydrogels structure in general. Different amount NiFe 2 O 4 nanoparticles loaded hydrogels will provide great benefits for optoelectronics and non-linear optical applications in the nanotechnology and photovoltaic devices. The different amount ionic materials loaded hydrogels can be categorized as non-ionic, ionic, zwitterionic and amphoteric electrolyte according to existence or absence of electrical charge in their chains.2 Especially, the dye ions loaded hydrogels play an important role in many areas in electronic packing, iontronics, enhance organic electronic performance devices, optoelectronics, microelectronics, brain electronics and microbial fuel cells applications.3-7 Furthermore, the applications of nanoparticles loaded materials in the form of powders, tubes, fiber and spheres are receiving a great deal of interest in nanoscience and nanotechnology. 8,9 The nanostructure loaded hydrogels have many applications such as high-efficiency an alkaline phosphatase (ALP) sensor, 10 23 and photoelectric devices 24 due to its high or low dielectric constants. Also, nano particle loaded dielectric materials in the visible spectral region can be made transparent electrically conductive. These materials are used as flat panel displays and the transparent conductive electrodes in solar cells. 25-27The dielectric properties and their technological applications of the NiFe 2 O 4 nanoparticles (NPs) loaded hydrogels have not been detailed examination depending on frequency and bias voltage so far. From hence, as an unlike to our previous study, [3][4][5][6][7] in the aim of pre...

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“…The band gap of HfO 2 is ca. 5.7 eV, whereas the dielectric constant is 25 [4,[10][11][12]15]. HfO 2 is also considered to be one of the most promising candidates to replace SiO 2 in Si-based gate electronic devices, because of their high dielectric constant and thermodynamic stability [1,16].…”

Section: Introductionmentioning

confidence: 99%

Characterization of HfO2 Optical Coatings Deposited by MF Magnetron Sputtering

et al. 2019

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The aim of this work is to determine the influence of medium frequency magnetron sputtering powers on the various properties of hafnium dioxide (HfO2) thin films. Microstructure observations show that an increase in the sputtering power has a significant influence on HfO2 films’ microstructure. As-deposited hafnia thin films exhibit nanocrystalline structure with a monoclinic phase, however thr rise of the sputtering power results in an increase of crystallite sizes. Atomic force microscopy investigations show that the surface of the deposited films is smooth, crack-free, and composed of visible grains. The surface roughness and the value of the water contact angle increase with the increase of the sputtering power. Measurements of the optical properties show that HfO2 coatings are transparent in the visible wavelength range. A higher sputtering power causes a decrease of an average transmittance level and a simultaneous increase of the real part of the refractive index. Nanoindentation measurements reveal that the thin film hardness and Young’s elastic modulus increase with an increase in the sputtering power. Moreover, the results of plasticity index H/E and plastic resistance parameter H3/E2 are discussed. Based on the obtained results, a correlation between the sputtering power and the structural, surface, and optical properties, as well as the hardness and Young’s elastic modulus, were determined.

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Doping dependent high-frequency dielectric properties of Hf1-xTixO2 nanoparticles

Cited by 14 publications

References 31 publications

The effect of post-process annealing on optical and electrical properties of mixed HfO2–TiO2 thin film coatings

The effect of post-process annealing on optical and electrical properties of mixed HfO2–TiO2 thin film coatings

Optic and Dielectric Properties of Different Amount NiFe₂O₄Nanoparticles Loaded Hydrogels: Synthetic Circuits Applications

Characterization of HfO2 Optical Coatings Deposited by MF Magnetron Sputtering

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Doping dependent high-frequency dielectric properties of Hf1-xTixO2 nanoparticles

Cited by 14 publications

References 31 publications

The effect of post-process annealing on optical and electrical properties of mixed HfO2–TiO2 thin film coatings

The effect of post-process annealing on optical and electrical properties of mixed HfO2–TiO2 thin film coatings

Optic and Dielectric Properties of Different Amount NiFe2O4Nanoparticles Loaded Hydrogels: Synthetic Circuits Applications

Characterization of HfO2 Optical Coatings Deposited by MF Magnetron Sputtering

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Optic and Dielectric Properties of Different Amount NiFe₂O₄Nanoparticles Loaded Hydrogels: Synthetic Circuits Applications