Atomic layer deposition (ALD) is gaining attention as a thin film deposition method, uniquely suitable for depositing uniform and conformal films on complex three-dimensional topographies. The deposition of a film of a given material by ALD relies on the successive, separated, and self-terminating gas–solid reactions of typically two gaseous reactants. Hundreds of ALD chemistries have been found for depositing a variety of materials during the past decades, mostly for inorganic materials but lately also for organic and inorganic–organic hybrid compounds. One factor that often dictates the properties of ALD films in actual applications is the crystallinity of the grown film: Is the material amorphous or, if it is crystalline, which phase(s) is (are) present. In this thematic review, we first describe the basics of ALD, summarize the two-reactant ALD processes to grow inorganic materials developed to-date, updating the information of an earlier review on ALD [R. L. Puurunen, J. Appl. Phys. 97, 121301 (2005)], and give an overview of the status of processing ternary compounds by ALD. We then proceed to analyze the published experimental data for information on the crystallinity and phase of inorganic materials deposited by ALD from different reactants at different temperatures. The data are collected for films in their as-deposited state and tabulated for easy reference. Case studies are presented to illustrate the effect of different process parameters on crystallinity for representative materials: aluminium oxide, zirconium oxide, zinc oxide, titanium nitride, zinc zulfide, and ruthenium. Finally, we discuss the general trends in the development of film crystallinity as function of ALD process parameters. The authors hope that this review will help newcomers to ALD to familiarize themselves with the complex world of crystalline ALD films and, at the same time, serve for the expert as a handbook-type reference source on ALD processes and film crystallinity.

Crystallinity of inorganic films grown by atomic layer deposition: Overview and general trends

There has been a resurgence of complex oxides of late owing to their ferroelectric and ferromagnetic properties. Although these properties had been recognized decades ago, the renewed interest stems from modern deposition techniques that can produce high quality materials and attractive proposed device concepts. In addition to their use on their own, the interest is building on the use of these materials in a stack also. Ferroelectrics are dielectric materials that have spontaneous polarization in certain temperature range and show nonlinear polarization–electric field dependence called a hysteresis loop. The outstanding properties of the ferroelectrics are due to non-centro-symmetric crystal structure resulting from slight distortion of the cubic perovskite structure. The ferroelectric materials are ferroelastic also in that a change in shape results in a change in the electric polarization (thus electric field) developed in the crystal and vice versa. Therefore they can be used to transform acoustic wav...

Processing, Structure, Properties, and Applications of PZT Thin Films

Due to the unique set of properties possessed by ZnO, thin films of ZnO have received more and more interest in the last 20?years as a potential material for applications such as thin-film transistors, light-emitting diodes and gas sensors. At the same time, the increasingly stringent requirements of the microelectronics industry, among other factors, have led to a dramatic increase in the use of atomic layer deposition (ALD) technique in various thin-film applications. During this time, the research on ALD-grown ZnO thin films has developed from relatively simple deposition studies to the fabrication of increasingly intricate nanostructures and an understanding of the factors affecting the fundamental properties of the films. In this review, we give an overview of the current state of ZnO ALD research including the applications that are being considered for ZnO thin films.

https://iopscience.iop.org/article/10.1088/0268-1242/29/4/043001/pdf

Atomic layer deposition of ZnO: a review

Behavior of tungsten under irradiation and plasma interaction

Green synthesis of zinc sulfide (ZnS) nanoparticles using Stevia rebaudiana Bertoni and evaluation of its cytotoxic properties

Water dispersible ZnS:Mn nanocrystals were synthesized by capping the surface of the nanocrystals with four kinds of aminoacids ligands: arginine, cystein, histidine, and methionine. The aminoacids capped ZnS:Mn nanocrystal powders were characterized by XRD, HR-TEM, EDXS, and FT-IR spectroscopy. The optical properties of the aminoacids capped ZnS:Mn colloidal nanocrystals were also measured by UV/Vis and solution photoluminescence (PL) spectroscopies in aqueous solvents. The solution PL spectra showed broad emission peaks around 575 nm (orange light emissions) with PL efficiencies in the range of 4.4 to 7.1%. The measured particle sizes for the aminoacid capped ZnS:Mn nanocrystals by HR-TEM images were in the range of 5.3 to 11.7 nm.

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Syntheses and Optical Properties of the Water-Dispersible ZnS:Mn Nanocrystals Surface Capped by L-Aminoacid Ligands: Arginine, Cysteine, Histidine, and Methionine

Effects of alloying elements and heat treatments on mechanical properties of Korean reduced-activation ferritic–martensitic steel

We studied effects of oxygen plasma treatment on the ferroelectric Pb(Zrx,Ti1−x)O3 (PZT) films prepared by a sol-gel method Electrical characteristics of the films were found to be improved considerably by exposure to the O2 plasma, with enhanced remanent polarization and decreased leakage current densities Chemical bonding analysis by means of x-ray photoelectron spectroscopy in the Pb 4f region indicated that the intensity from the perovskite PZT phase increased considerably after the O2 plasma treatment, giving rise to the improved performances of the PZT films

Oxygen plasma effects on sol-gel-derived lead-zirconate-titanate thin films

5+ were investigated. The dielectric properties were analyzed and the relationship between the properties and structure of doped BaTiO3 was established. The fine-grain and high density of the doped BaTiO3 ceramics resulted in excellent dielectric properties. The dielectric properties of this solid solutions were improved by adding a small amount of dopants. The transition temperature of the 1.0 mole% Ta 5+ doped BaTiO3 solid solution was ∼110 o C with a dielectric constant of 3000 at room temperature. At temperatures above the Curie temperatures, the dielectric constant followed the Curie-Weiss law.

https://www.koreascience.or.kr:443/article/JAKO200902727033707.pdf

Microstructural Characterization and Dielectric Properties of Barium Titanate Solid Solutions with Donor Dopants

Hydrogen permeation through nickel has been studied for decades owing to its importance from both scientific and industrial aspects. Considering the applications for nuclear hydrogen production as well as nuclear fusion, we carried out a series of hydrogen permeation experiments in the wide temperature range of 450–850 °C by using a nickel membrane. The permeability, diffusivity, and solubility of hydrogen for nickel were determined. Our results were compared with the ones previously reported by others; because their works were measured at low temperatures compared with this work, their values were extrapolated for the purpose of comparisons. Results and discussions for hydrogen permeation studies are presented here.

S. J. Noh

Papers

Syntheses and Optical Properties of the Water-Dispersible ZnS:Mn Nanocrystals Surface Capped by L-Aminoacid Ligands: Arginine, Cysteine, Histidine, and Methionine

Effects of alloying elements and heat treatments on mechanical properties of Korean reduced-activation ferritic–martensitic steel

Oxygen plasma effects on sol-gel-derived lead-zirconate-titanate thin films

Microstructural Characterization and Dielectric Properties of Barium Titanate Solid Solutions with Donor Dopants

Measurement of hydrogen permeation through nickel in the elevated temperature range of 450 – 850 °C