Effect of Process Temperature and Reaction Cycle Number on Atomic Layer Deposition of TiO2 Thin Films Using TiCl4 and H2O Precursors: Correlation Between Material Properties and Process Environment

Chiappim, William; Testoni, G. E.; Lima, Jhonatan S. Brandão de; Medeiros, H. S.; Pessoa, Rodrigo Sávio; Grigorov, K. G.; Vieira, Lúcia; Maciel, Homero Santiago

doi:10.1007/s13538-015-0383-2

Cited by 43 publications

(26 citation statements)

References 51 publications

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“…The TiO x films show an excess of oxygen, i.e., x values ranging from 2.13 ± 0.01 to 2.33 ± 0.01, as can be seen in Figure 3. These results differ from those described for thermal ALD TiO 2 films, in which either stoichometric or oxygen-deficient films are obtained [52]. The increase of oxygen content in PEALD TiO 2 films may be related to the higher reactivity of O 2 plasma compared to the water precursor used in thermal ALD.…”

Section: Structure and Morphologycontrasting

confidence: 88%

“…The crystalline condition of pure TiO 2 thin films due to the strong peak at 144 cm −1 is clearly evidenced. On the other hand, for the TiO 2 /Al 2 O 3 nanolaminate, the main peaks of the anatase phase were not observed, and the rutile phase is formed above 500 • C for silicon substrate [28,37,52,53], which suggests that the film is amorphous or partially crystalline. Figure 4b shows the micro-Raman spectra evidencing the shift and the full width at half maximum (FWHM) of the E g peak at 144 cm −1 .…”

Section: Structure and Morphologymentioning

confidence: 94%

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MOS Capacitance Measurements for PEALD TiO2 Dielectric Films Grown under Different Conditions and the Impact of Al2O3 Partial-Monolayer Insertion

et al. 2020

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In this paper, we report the plasma-enhanced atomic layer deposition (PEALD) of TiO2 and TiO2/Al2O3 nanolaminate films on p-Si(100) to fabricate metal-oxide-semiconductor (MOS) capacitors. In the PEALD process, we used titanium tetraisopropoxide (TTIP) as a titanium precursor, trimethyl aluminum (TMA) as an aluminum precursor and O2 plasma as an oxidant, keeping the process temperature at 250 °C. The effects of PEALD process parameters, such as RF power, substrate exposure mode (direct or remote plasma exposure) and Al2O3 partial-monolayer insertion (generating a nanolaminate structure) on the physical and chemical properties of the TiO2 films were investigated by Rutherford backscattering spectroscopy (RBS), Raman spectroscopy, grazing incidence X-ray diffraction (GIXRD), and field emission scanning electron microscopy (FESEM) techniques. The MOS capacitor structures were fabricated by evaporation of Al gates through mechanical mask on PEALD TiO2 thin film, followed by evaporation of an Al layer on the back side of the Si substrate. The capacitors were characterized by current density-voltage (J-V), capacitance-voltage (C-V) and conductance-voltage (G-V) measurements. Our results indicate that RF power and exposure mode promoted significant modifications on the characteristics of the PEALD TiO2 films, while the insertion of Al2O3 partial monolayers allows the synthesis of TiO2/Al2O3 nanolaminate with well-spaced crystalline TiO2 grains in an amorphous structure. The electrical characterization of the MOS structures evidenced a significant leakage current in the accumulation region in the PEALD TiO2 films, which could be reduced by the addition of partial-monolayers of Al2O3 in the bulk of TiO2 films or by reducing RF power.

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Section: Structure and Morphologycontrasting

confidence: 88%

Section: Structure and Morphologymentioning

confidence: 94%

MOS Capacitance Measurements for PEALD TiO2 Dielectric Films Grown under Different Conditions and the Impact of Al2O3 Partial-Monolayer Insertion

et al. 2020

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“…Certainly, the selection of Ti and O 2 precursors is another important factor due to the different activation kinetics for different precursors. Several works have suggested that the crystallization process is initiated at the temperature range of 165–250°C (Aarik et al, 1995, 2013; Saha et al, 2014; Chiappim et al, 2016). For example, an 11 nm thin anatase TiO 2 film was obtained at deposition temperature of 225°C when TiCl 4 and H 2 O were employed as precursors (Aarik et al, 2013).…”

Section: Resultsmentioning

confidence: 99%

TiO2 ALD Coating of Amorphous TiO2 Nanotube Layers: Inhibition of the Structural and Morphological Changes Due to Water Annealing

Sopha

Zazpe

et al. 2019

Front. Chem.

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The present work presents a strategy to stabilize amorphous anodic self-organized TiO2 nanotube layers against morphological changes and crystallization upon extensive water soaking. The growth of needle-like nanoparticles was observed on the outer and inner walls of amorphous nanotube layers after extensive water soakings, in line with the literature on water annealing. In contrary, when TiO2 nanotube layers uniformly coated by thin TiO2 using atomic layer deposition (ALD) were soaked in water, the growth rates of needle-like nanoparticles were substantially reduced. We investigated the soaking effects of ALD TiO2 coatings with different thicknesses and deposition temperatures. Sufficiently thick TiO2 coatings (≈8.4 nm) deposited at different ALD process temperatures efficiently hamper the reactions between water and F− ions, maintain the amorphous state, and preserve the original tubular morphology. This work demonstrates the possibility of having robust amorphous 1D TiO2 nanotube layers that are very stable in water. This is very practical for diverse biomedical applications that are accompanied by extensive contact with an aqueous environment.

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“…While for Al 2 O 3 films the cycle times were 0.15, 0.75, 0.15 and 0.75 s for the TMA pulse, purge, H 2 O pulse and another purge, respectively. These are optimal cycle time conditions investigated in early studies [29,30,31,32,33,34]. The vapors of TiCl 4 , TMA and H 2 O were led into the reaction chamber from external reservoirs kept with liquid TiCl 4 (99.95 %, Sigma-Aldrich, São Paulo, Brazil), liquid TMA (97%, Sigma-Aldrich) and deionized water at temperature of 21 °C.…”

Section: Methodsmentioning

confidence: 99%

Atomic Layer Deposited TiO2 and Al2O3 Thin Films as Coatings for Aluminum Food Packaging Application

et al. 2019

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Titanium dioxide (TiO2) and aluminum oxide (Al2O3) coatings have been investigated in a wide range of bio-applications due to their biodegradation and biocompatibility properties, that are key parameters for their use in the food packaging and biomedical devices fields. The present study evaluates and compares the electrochemical behavior of the non-coated, commercial resin-coated, TiO2-coated and Al2O3-coated aluminum in commercial beer electrolyte. For this, TiO2 and Al2O3 thin films were deposited on aluminum (Al) substrates using atomic layer deposition (ALD). The evaluation of the corrosion barrier layer properties was performed by linear sweep voltammetry (LSV) during 10 min and electrochemical impedance spectroscopy (EIS). In addition, profilometry, grazing incidence X-ray diffractometry (GIXRD), scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FT-IR) analyses were performed to investigate the physical and chemical properties of the pristine and / or corroded samples. TiO2 and Al2O3 films presented an amorphous structure, a morphology that follows Al substrate surface, and a thickness of around 100 nm. Analysis of LSV data showed that ALD coatings promoted a considerable increase in corrosion barrier efficiency being 86.3% for TiO2-coated Al and 80% for Al2O3-coated Al in comparison with 7.1% of commercial resin-coated Al. This is mainly due to the lower electrochemical porosity, 11.4% for TiO2-coated Al and 20.4% for Al2O3-coated Al in comparison with 96% of the resin-coated Al, i.e. an increase of up to twofold in the protection of Al when coated with TiO2 compared to Al2O3. The EIS results allow us to complement the discussions about the reduced corrosion barrier efficiency of the Al2O3 film for beer electrolyte once SEM and FT-IR analyzes did not show drastic changes in both investigated ALD films after the corrosion assays. The above results indicate that ALD TiO2 and Al2O3 films may be a viable alternative to replace the synthetic resin coatings frequently used in aluminum cans of use in the food industry.

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Effect of Process Temperature and Reaction Cycle Number on Atomic Layer Deposition of TiO2 Thin Films Using TiCl4 and H2O Precursors: Correlation Between Material Properties and Process Environment

Abstract: How to citeComplete issue More information about this article Journal's homepage in redalyc.org Scientific Information System Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Non-profit academic project, developed under the open access initiative

Cited by 43 publications

References 51 publications

MOS Capacitance Measurements for PEALD TiO2 Dielectric Films Grown under Different Conditions and the Impact of Al2O3 Partial-Monolayer Insertion

MOS Capacitance Measurements for PEALD TiO2 Dielectric Films Grown under Different Conditions and the Impact of Al2O3 Partial-Monolayer Insertion

TiO2 ALD Coating of Amorphous TiO2 Nanotube Layers: Inhibition of the Structural and Morphological Changes Due to Water Annealing

Atomic Layer Deposited TiO2 and Al2O3 Thin Films as Coatings for Aluminum Food Packaging Application

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