Search results for "roska"
showing 10 items of 56 documents
Unusual stoichiometry control in the atomic layer deposition of manganese borate films from manganese bis(tris(pyrazolyl)borate) and ozone
2016
The atomic layer deposition (ALD) of films with the approximate compositions Mn3(BO3)2 and CoB2O4 is described using MnTp2 or CoTp2 [Tp ¼ tris(pyrazolyl)borate] with ozone. The solid state decomposition temperatures of MnTp2 and CoTp2 are 370 and 340 C, respectively. Preparative-scale sublimations of MnTp2 and CoTp2 at 210 C/0.05 Torr afforded >99% recoveries with <0.1% nonvolatile residues. Self-limited ALD growth was demonstrated at 325 C for MnTp2 or CoTp2 with ozone as the coreactant. The growth rate for the manganese borate process was 0.19 A˚ /cycle within the ALD window of 300–350 C. The growth rate for the cobalt borate process was 0.39–0.42 A˚ /cycle at 325 C. X-ray diffraction of …
Antiferromagnetism and p‐type conductivity of nonstoichiometric nickel oxide thin films
2020
Plasma‐enhanced atomic layer deposition was used to grow non‐stoichiometric nickel oxide thin films with low impurity content, high crystalline quality, and p‐type conductivity. Despite the non‐stoichiometry, the films retained the antiferromagnetic property of NiO.
Atomic layer deposition of Ti-Nb-O thin films onto electrospun fibers for fibrous and tubular catalyst support structures
2018
Here, the authors report on the preparation of core-shell carbon-ceramic fibrous as well as ceramic tubular catalyst supports utilizing electrospinning and atomic layer deposition (ALD). In this paper, ALD of Ti-Nb-O thin films using TiCl4, Nb(OEt)5, and H2O as precursors is demonstrated. According to the time-of-flight-elastic recoil detection analysis and Rutherford backscattering spectrometry, carbon and hydrogen impurities were relatively low, but depend on the pulsing ratio of the precursors. Optimized ALD process was used for coating of sacrificial electrospun polyvinyl alcohol (PVA) template fibers to yield tubular Ti-Nb-O structures after thermal or solution based PVA removal. Anoth…
Reaction pathways for atomic layer deposition with lithium hexamethyl disilazide, trimethyl phosphate, and oxygen plasma
2020
Atomic layer deposition (ALD) of lithium-containing films is of interest for the development of next-generation energy storage devices. Lithium hexamethyl disilazide (LiHMDS) is an established precursor to grow these types of films. The LiHMDS molecule can either be used as a single-source precursor molecule for lithium or as a dual-source precursor molecule for lithium and silicon. Single-source behavior of LiHMDS is observed in the deposition process with trimethylphosphate (TMP) resulting in the deposition of crystalline lithium phosphate (Li3PO4). In contrast, LiHMDS exhibits dual-source behavior when combined with O2 plasma, resulting in a lithium silicate. Both processes were characte…
Phosphites as precursors in atomic layer deposition thin film synthesis
2021
We here demonstrate a new route for deposition of phosphorous based materials by atomic layer deposition (ALD) using the phosphites Me3PO3 or Et3PO3 as precursors. These contain phosphorous in the oxidation state (III) and are open for deposition of reduced phases by ALD. We have investigated their applicability for the synthesis of LiPO and AlPO materials and characterized their growth by means of in situ quartz crystal microbalance. Phosphites are good alternatives to the established phosphate-based synthesis routes as they have high vapor pressure and are compatible with water as a coreactant during deposition. The deposited materials have been characterized using XPS, x-ray fluorescence…
Structural and chemical analysis of annealed plasma-enhanced atomic layer deposition aluminum nitride films
2016
Plasma-enhanced atomic layer deposition was utilized to grow aluminum nitride (AlN) films on Si from trimethylaluminum and N2:H2 plasma at 200 °C. Thermal treatments were then applied on the films which caused changes in their chemical composition and nanostructure. These changes were observed to manifest in the refractive indices and densities of the films. The AlN films were identified to contain light element impurities, namely, H, C, and excess N due to nonideal precursor reactions. Oxygen contamination was also identified in the films. Many of the embedded impurities became volatile in the elevated annealing temperatures. Most notably, high amounts of H were observed to desorb from the…
Cellulose-inorganic hybrids of strongly reduced thermal conductivity
2022
Abstract The employment of atomic layer deposition and spin coating techniques for preparing inorganic-organic hybrid multilayer structures of alternating ZnO-CNC layers was explored in this study. Helium ion microscopy and X-ray reflectivity showed the superlattice formation for the nanolaminate structures and atomic force microscopy established the efficient control of the CNCs surface coverage on the Al-doped ΖnO by manipulating the concentration of the spin coating solution. Thickness characterization of the hybrid structures was performed via both ellipsometry and X-ray reflectivity and the thermal conductivity was examined by time domain thermoreflectance technique. It appears that ev…
Properties of atomic layer deposited nanolaminates of zirconium and cobalt oxides
2018
Producción Científica
Aluminum oxide/titanium dioxide nanolaminates grown by atomic layer deposition: Growth and mechanical properties
2017
Atomic layer deposition (ALD) is based on self-limiting surface reactions. This and cyclic process enable the growth of conformal thin films with precise thickness control and sharp interfaces. A multilayered thin film, which is nanolaminate, can be grown using ALD with tuneable electrical and optical properties to be exploited, for example, in the microelectromechanical systems. In this work, the tunability of the residual stress, adhesion, and mechanical properties of the ALD nanolaminates composed of aluminum oxide (Al2O3) and titanium dioxide (TiO2) films on silicon were explored as a function of growth temperature (110-300 C), film thickness (20-300 nm), bilayer thickness (0.1-100 nm),…
Thermal atomic layer deposition of AlOxNy thin films for surface passivation of nano-textured flexible silicon
2019
Abstract Aluminum oxynitride (AlOxNy) films with different nitrogen concentration are prepared by thermal atomic layer deposition (ALD) for flexible nano-textured silicon (NT-Si) surface passivation. The AlOxNy films are shown to exhibit a homogeneous nitrogen-doping profile and the presence of an adequate amount of hydrogen, which is investigated by Time-of-Fight Elastic Recoil Detection Analysis (ToF-ERDA). The effective minority carrier lifetimes are measured after the NT-Si surface passivation; the minimum surface recombination velocity (SRV) of 5 cm-s−1 is achieved with the AlOxNy film in comparison to the Al2O3 and AlN films (SRV of 7–9 cm-s−1). The better SRV with AlOxNy film is due …