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Atomic layer deposition

About: Atomic layer deposition is a research topic. Over the lifetime, 19821 publications have been published within this topic receiving 477332 citations. The topic is also known as: ALD.


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Patent
22 Dec 2005
TL;DR: In this article, a process for producing bismuth-containing oxide thin films by atomic layer deposition is described, which can be used as ferroelectric or dielectric materials in integrated circuits and as superconductor materials.
Abstract: Processes are provided for producing bismuth-containing oxide thin films by atomic layer deposition. In preferred embodiments an organic bismuth compound having at least one monodentate alkoxide ligand is used as a bismuth source material. Bismuth-containing oxide thin films can be used, for example, as ferroelectric or dielectric materials in integrated circuits and as superconductor materials.

115 citations

Journal ArticleDOI
TL;DR: In this article, the coordination and interface of Al2O3 formed on Si(001) by atomic layer deposition (ALD) were studied using electron energy-loss spectroscopy in a transmission electron microscope.
Abstract: The coordination and interface of Al2O3 formed on Si(001) by atomic layer deposition (ALD) were studied using electron energy-loss spectroscopy in a transmission electron microscope. Al energy-loss near-edge structures (ELNESs) were interpreted using first-principles calculations. The Al L23 ELNESs show two peaks at 78.2 and 79.7 eV, which originate from tetrahedrally and octahedrally coordinated aluminum, respectively. The depth profile of coordination in ALD Al2O3/Si was investigated. While both tetrahedrally and octahedrally coordinated Al atoms exist in the ALD Al2O3, the former is dominant near the interface. Aluminum silicate was detected near the interface, and it may cause the difference in aluminum coordination.

115 citations

Journal ArticleDOI
TL;DR: In this paper, HfO2 thin films were deposited on Si wafers using an atomic layer deposition technique at temperatures ranging from 200 to 400°C with HfCl4 as the precursor and H2O as the oxidant.
Abstract: HfO2 thin films were deposited on Si wafers using an atomic layer deposition technique at temperatures ranging from 200 to 400 °C with HfCl4 as the precursor and H2O as the oxidant. The time-dependent interfacial-layer growth behavior was dependent on the deposition temperature. The interfacial layer grew with increasing deposition time at 200 °C. However, the film thicknesses decreased with increasing deposition time after reaching a certain maximum value at 300 and 400 °C due to the enhanced dissolution of SiOx into the growing films at these temperatures. Post-annealing at 800 °C under a N2 atmosphere resulted in the precipitation of a Si-rich interfacial layer even for the initially interfacial layer free films. This had the effect of reducing the capacitance density of the films.

115 citations

Journal ArticleDOI
TL;DR: The low temperature ALD-grown TiO(2) films are dense, stable and robust with capability of conformal coating on nanostructural surfaces, showing a promising interface layer for achieving air-stable plastic OSCs with roll-to-roll mass production potential.
Abstract: Organic solar cells (OSCs) with inverted structure have attracted much attention in recent years because of their improved device air stability due to the use of stable materials for electrodes and interface layers. In this work, TiO(2) films, fabricated using low temperature (e.g., 130-170 °C) atomic layer deposition (ALD) on ITO substrates, are used as electron selective interface layers to investigate inverted OSCs. It is found that though the as-deposited TiO(2) films are high resistive due to the presence of oxygen defects, the defects can be significantly reduced by light soaking. PV cells with 15-nm-thick amorphous-TiO(2) layers fabricated at low temperature show better performance than those with poly crystal TiO(2) with same thickness deposited at 250 °C. The low temperature ALD-grown TiO(2) films are dense, stable and robust with capability of conformal coating on nanostructural surfaces, showing a promising interface layer for achieving air-stable plastic OSCs with roll-to-roll mass production potential.

115 citations

Journal ArticleDOI
TL;DR: In this article, hollow cathode plasma was used for low-temperature plasma-assisted atomic layer deposition (PA-ALD) of crystalline AlN, GaN and AlxGa1−xN thin films with low impurity concentrations.
Abstract: The authors report on the use of hollow cathode plasma for low-temperature plasma-assisted atomic layer deposition (PA-ALD) of crystalline AlN, GaN and AlxGa1−xN thin films with low impurity concentrations. Depositions were carried out at 200 °C using trimethylmetal precursors and NH3 or N2/H2 plasma. X-ray photoelectron spectroscopy showed the presence of 2.5–3 at.% O in AlN and 1.5–1.7 at.% O in GaN films deposited using NH3 and N2/H2 plasma, respectively. No C impurities were detected within the films. Secondary ion mass spectroscopy analyses performed on the films deposited using NH3 plasma revealed the presence of O, C (both <1 at.%), and H impurities. GIXRD patterns indicated polycrystalline thin films with wurtzite crystal structure. Hollow cathode PA-ALD parameters were optimized for AlN and GaN thin films using N2/H2 plasma. Trimethylmetal and N2/H2 saturation curves evidenced the self-limiting growth of AlN and GaN at 200 °C. AlN exhibited linear growth with a growth per cycle (GPC) of ∼1.0 A. For GaN, the GPC decreased with the increasing number of deposition cycles, indicating substrate-enhanced growth. The GPC calculated from a 900-cycle GaN deposition was 0.22 A. Ellipsometric spectra of the samples were modeled using the Cauchy dispersion function, from which the refractive indices of 59.2 nm thick AlN and 20.1 nm thick GaN thin films were determined to be 1.94 and 2.17 at 632 nm, respectively. Spectral transmission measurements of AlN, GaN and AlxGa1−xN thin films grown on double side polished sapphire substrates revealed near-ideal visible transparency with minimal absorption. Optical band edge values of the AlxGa1−xN films shifted to lower wavelengths with the increasing Al content, indicating the tunability of band edge values with the alloy composition.

115 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023542
20221,013
20211,032
20201,269
20191,298
20181,322