Nucleation and growth behavior of aluminum nitride film using thermal atomic layer deposition

Yun, Hee Ju; Kim, Hogyoung; Choi, Byung Joon

doi:10.1016/j.ceramint.2020.02.118

Cited by 20 publications

(11 citation statements)

References 47 publications

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“…The variation of growth rate in different solid-solution films may be ascribed to different nucleation sites on different substrates. [42] Therefore, the significantly decreased growth rates of ZnO in G10Z5 and G7Z5 are attributed to the nucleation delay of ZnO on amorphous GaN. On the other hand, the increased growth rates of GaN in G5Z7 or G5Z10 imply that GaN can nucleate more easily on ZnO with a crystalline wurtzite structure.…”

Section: Atomic Stacking In the Solid Solutionsmentioning

confidence: 98%

Formation Mechanism and Bandgap Reduction of GaN–ZnO Solid‐Solution Thin Films Fabricated by Nanolamination of Atomic Layer Deposition

2023

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Compared with the fossil fuels, hydrogen possesses several advantages such as zero carbon emission, versatile production, and high energy density. [1] Solar to hydrogen conversion by photocatalysis is sustainable and renewable without any external power. Therefore, in the past decades numerous efforts have been made to improve photocatalytic hydrogen generation efficiency. For wide bandgap semiconductor materials, they can utilize only a small fraction of solar energy. For example, anatase TiO 2 (E g = 3.2 eV) can only absorb the wavelengths below 388 nm with the theoretical maximum photoconversion efficiency of 1.3% under the AM 1.5 solar spectrum. [2] To improve the photocatalytic hydrogen evolution efficiency, the strategies of energy band engineering by doping, [3,4] solid solution, [5,6] and localized surface plasmon resonance [7,8] have been adopted to achieve bandgap narrowing and visible light absorption. Li et al. [9] reported controllable bandgaps of Zn 1−x Cd x S from 3.10 to 2.30 eV by increasing x from 0 to 1, achieving the visible light photocatalytic hydrogen evolution. Another approach of bandgap engineering is to alloy III-V and II-VI semiconductors. [10] Among all the possible solid solutions, the quaternary GaP-ZnSe, GaP-ZnS, and GaN-ZnO systems exhibit abnormal bandgaps which are smaller than those of the pure component semiconductors. [10] For example, Yang et al. [11] fabricated (GaP) 1−x (ZnSe) x solid-solution nanowires by chemical vapor deposition (CVD). A preferred solubility in the range of x = 0.182-0.209 was obtained, resulting in varied bandgaps of 1.95-2.20. [11] Hart and Allan [12] proposed fabrication of GaP-ZnS solid solution because both GaP and ZnS have the same zinc blende structure. Their calculation indicated that the bandgap of (GaP) 0.875 (ZnS) 0.125 can be reduced to 1.9 eV with a specific ordering of the atoms. This bandgap is lower than those of bare GaP (2.24 eV) and ZnS (3.54 eV). [12] Although the bandgaps of these two solid-solution systems have been brought down to the visible light region, they are not suitable for photocatalytic hydrogen evolution presumably owing to the corrosion susceptibility of GaP. [13] By contrast, the GaN-ZnO system was first experimentally demonstrated to be a promising material for visible-light-driven photocatalytic hydrogen evolution by Domen's group. [5,14,15] Since both GaN and ZnO have a hexagonal close Nanolamination of GaN and ZnO layers by atomic layer deposition (ALD) is employed to fabricate GaN-ZnO homogenous solid-solution thin films because it offers more precise control of the stoichiometry. By varying the ALD cycle ratios of GaN:ZnO from 5:10 to 10:5, the (GaN) 1−x (ZnO) x films with 0.39 ≦ x ≦ 0.79 are obtained. The formation of solid solution is explained based on the atomic stacking and preferred orientation of the layers of GaN and ZnO. However, the growth rates of GaN and ZnO during the lamination process are different from those of pure GaN and ZnO films. It is found that GaN grows faster on ZnO, whereas ZnO grows sl...

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Section: Atomic Stacking In the Solid Solutionsmentioning

confidence: 98%

Formation Mechanism and Bandgap Reduction of GaN–ZnO Solid‐Solution Thin Films Fabricated by Nanolamination of Atomic Layer Deposition

2023

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“…[53] When there are no or fewer reaction sites between the buffer layer and the substrate, the ALD process becomes island-like growth (Volmer-Weber), which will inhibit nucleation and delay film growth, resulting in a pinhole layer. [54] Duan's research group reported a ZnO/Mg:Ag-alloy/ ZnO top transparent DMD composite electrode equipped on transparent OLEDs, and by using ALD technology to deposit ZnO on ultra-thin Mg:Ag-alloy, the ZnO layer plays the role of antireflection and encapsulation layer, and the final AVT of the electrode is as high as 84.6%. [53] Recently, the research group applied ALD technology to ST-PSCs, deposited ZnO on Ag through ALD, and designed the ZnO/Ag/ZnO composite electrode structure.…”

Section: Transparent Conductive Oxide (Tco) Electrodesmentioning

confidence: 99%

Recent Progresses on Transparent Electrodes and Active Layers Toward Neutral, Color Semitransparent Perovskite Solar Cells

et al. 2023

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Semitransparent perovskite solar cells (ST‐PSCs) are highly promising for application in building‐integrating photovoltaics (BIPVs) due to their potential in tunable transparency and color. However, the comprehensive performance of ST‐PSCs falls quite short of the ideal requirements for BIPV. Herein, more attention is to review how to balance transparency and power conversion efficiency for ST‐PSCs. Optimizing transparent electrodes and the active layers are interesting strategies to achieve the transparency required by devices. In addition, to obtain color ST‐PSCs, tuning the bandgap of perovskite layers and designing the optical structure of the electrode are effective strategies. Last but not least, three significant optical evaluation indexes of ST‐PSCs are described in the supporting information: average visible transmittance, color rendering index, and light utilization efficiency.

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“…As native substrates of III-nitrides are hardly available (due to the difficulties with incorporating nitrogen), they are commonly grown on mismatched substrates involving thick buffer layers and high temperatures well above the back-end-of-line (BEOL) limit. , Atomic layer deposition (ALD) is a suitable candidate to investigate thin-film deposition of III-nitrides with a reduced thermal budget. In ALD, high conformality and large area uniformity with thickness control at a sub-monolayer scale are enabled by using sequential self-limiting vapor-solid reactions. ,− It has found use in numerous fabrication processes of devices and circuits with <10 nm feature sizes. − ,, Many authors have reported on ALD of Groups III–V (III–V) compounds since Nishizawa et al’s first paper on GaAs in 1985 (). ,, ALD of AlN commenced in the early 1990s with trimethylaluminum (TMA) as the metal precursor and ammonia (NH 3 ) as the nitrogen precursor. − Currently, a myriad of precursors, precursor combinations, and reactivity-enhancing techniques have been used to alter the ALD temperature window, limit the incorporation of impurities, and improve stoichiometry and crystallinity. Some authors using TMA as metal precursors have resorted to plasma-enhanced deposition to increase the reactivity of NH 3 at reduced temperatures. ,,,,− ,− One author has employed ultraviolet (UV) radiation during TMA injection...…”

Section: Introductionmentioning

confidence: 99%

Area-Selective Low-Pressure Thermal Atomic Layer Deposition of Aluminum Nitride

van der Wel,

van der Zouw,

Aarnink

et al. 2023

J. Phys. Chem. C

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This work demonstrates intrinsic area-selective deposition of AlN films by thermal atomic layer deposition (ALD). Using sequential pulses of trimethylaluminum and NH 3 at a substrate temperature of 623 K, polycrystalline AlN was selectively formed on a thin layer of sputtered AlN that was patterned on thermal SiO 2 grown on Si substrates. A pretreatment to remove native AlO x N y facilitated the selective growth of ALD-AlN. Transmission electron microscopy, X-ray photoelectron spectroscopy, spectroscopic ellipsometry, and atomic force microscopy examined the interfaces and layer thickness. As reported in this article, the deposition of AlN exhibits intrinsic selectivity, a trait that can be exploited to grow other III-nitrides selectively, such as GaN.

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Nucleation and growth behavior of aluminum nitride film using thermal atomic layer deposition

Cited by 20 publications

References 47 publications

Formation Mechanism and Bandgap Reduction of GaN–ZnO Solid‐Solution Thin Films Fabricated by Nanolamination of Atomic Layer Deposition

Formation Mechanism and Bandgap Reduction of GaN–ZnO Solid‐Solution Thin Films Fabricated by Nanolamination of Atomic Layer Deposition

Recent Progresses on Transparent Electrodes and Active Layers Toward Neutral, Color Semitransparent Perovskite Solar Cells

Area-Selective Low-Pressure Thermal Atomic Layer Deposition of Aluminum Nitride

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