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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.


Papers
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Journal ArticleDOI
TL;DR: In this article, the physical processes in plasma-assisted ALD affecting conformality were identified and investigated through Monte Carlo simulations, where the conformality was dictated by the recombination probability r, the reaction probability s, and the diffusion rate of particles.
Abstract: For plasma-assisted atomic layer deposition (ALD), reaching conformal deposition in high aspect ratio structures is less straightforward than for thermal ALD due to surface recombination loss of plasma radicals. To obtain a detailed insight into the consequences of this additional radical loss, the physical processes in plasma-assisted ALD affecting conformality were identified and investigated through Monte Carlo simulations. The conformality was dictated by the recombination probability r, the reaction probability s, and the diffusion rate of particles. When recombination losses play a role, the saturation dose depended strongly on the value of r. For the deposition profiles, a minimum at the bottom of trench structures was observed (before reaching saturation), which was more pronounced with larger values of r. In turn, three deposition regimes could be identified, i.e., a reaction-limited regime, a diffusion-limited regime, and a new regime that is recombination-limited. For low values of r, conformal deposition in high aspect ratio structures can still be achieved, as observed for several metal oxides, even for aspect ratios as large as 30. For high surface recombination loss probabilities, as appears to be the case for many metals, achieving a reasonable conformality becomes challenging, especially for aspect ratios >10.

142 citations

Journal ArticleDOI
TL;DR: In this article, an excellent photoanode of black BiVO4@amorphous TiO2−x to tackle the problem of wide bandgap and poor photostability is reported.
Abstract: Recent advances in solar water splitting by using BiVO4 as a photoanode have greatly optimized charge carrier and reaction dynamics, but relatively wide bandgap and poor photostability are still bottlenecks. Here, an excellent photoanode of black BiVO4@amorphous TiO2−x to tackle both problems is reported. Its applied bias photon‐to‐current efficiency for solar water splitting is up to 2.5%, which is a new record for a single oxide photon absorber. This unique core–shell structure is fabricated by coating amorphous TiO2 on nanoporous BiVO4 with the aid of atomic layer deposition and further hydrogen plasma treatment at room temperature. The black BiVO4 with moderate oxygen vacancies reveals a bandgap reduction of ≈0.3 eV and significantly enhances solar utilization, charge transport and separation simultaneously, compared with conventional BiVO4. The amorphous layer of TiO2−x acts as both oxygen‐evolution catalyst and protection layer, which suppresses anodic photocorrosion to stabilize black BiVO4. This configuration of black BiVO4@amorphous TiO2−x may provide an effective strategy to prompt solar water splitting toward practical applications.

141 citations

Journal ArticleDOI
TL;DR: In this paper, Ta 2 O 5 films were grown in atomic layer deposition (ALD) process on barium borosilicate glass substrates in the temperature range of 300-400°C from TaCl 5 and H 2 O. The film crystallinity was modified by precursor dosing and substrate temperature.

141 citations

Journal ArticleDOI
TL;DR: In this paper, the reduction in III-V interfacial oxides by atomic layer deposition of Al2O3 on InGaAs is studied by interrupting the deposition following individual trimethyl aluminum (TMA) and water steps (half cycles) and interrogation of the resultant surface reactions using in situ monochromatic x-ray photoelectron spectroscopy (XPS) TMA is found to reduce the interfacial Oxides during the initial exposure.
Abstract: The reduction in III–V interfacial oxides by atomic layer deposition of Al2O3 on InGaAs is studied by interrupting the deposition following individual trimethyl aluminum (TMA) and water steps (half cycles) and interrogation of the resultant surface reactions using in situ monochromatic x-ray photoelectron spectroscopy (XPS) TMA is found to reduce the interfacial oxides during the initial exposure Concentrations of Ga oxide on the surface processed at 300 °C are reduced to a concentration on the order of a monolayer, while AsOx species are below the level of detection of XPS

141 citations

Patent
11 Oct 2006
TL;DR: In this article, an MIS capacitor with low leakage and high capacitance is disclosed, where a layer of hemispherical grained polysilicon (HSG) is formed as a lower electrode and a metal nitride upper electrode is formed over the dielectric layer by a deposition technique or by atomic layer deposition.
Abstract: An MIS capacitor with low leakage and high capacitance is disclosed. A layer of hemispherical grained polysilicon (HSG) is formed as a lower electrode. Prior to the dielectric formation, the hemispherical grained polysilicon layer may be optionally subjected to a nitridization or anneal process. A dielectric layer of aluminum oxide (Al2O3), or a composite stack of interleaved layers of aluminum oxide and other metal oxide dielectric materials, is fabricated over the hemispherical grained polysilicon layer and after the optional nitridization or anneal process. The dielectric layer of aluminum oxide (Al2O3) or the aluminum oxide composite stack may be optionally subjected to a post-deposition treatment to further increase the capacitance and decrease the leakage current. A metal nitride upper electrode is formed over the dielectric layer or the composite stack by a deposition technique or by atomic layer deposition.

141 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