Island growth in the atomic layer deposition of zirconium oxide and aluminum oxide on hydrogen-terminated silicon: Growth mode modeling and transmission electron microscopy

New TEM grids coated with ultrathin amorphous films have been developed using atomic layer deposition technique. The amorphous films can withstand temperatures over in air and in vacuum when the thickness of the film is 2 nm, and up to in air when the thickness is 25 nm, which makes heating TEM grids with nanoparticles up to in air and immediate TEM observation without interrupting the nanoparticles possible. Such coated TEM grids are very much desired for applications in high-temperature high-resolution transmission electron microscopy.

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Ultra-Thin Integrated ALD Al2O3 Electron-Transparent Windows for TEM Nanoreactor Applications

Proceedings ◽

10.3390/proceedings2131001 ◽

2018 ◽

Vol 2 (13) ◽

pp. 1001

Author(s):

Levar Goossen ◽

Jia Wei ◽

Gregory Pandraud ◽

Violeta Prodanovic ◽

Pasqualina M. Sarro

Keyword(s):

Electron Microscope ◽

Atomic Layer Deposition ◽

Aluminum Oxide ◽

Transmission Electron Microscope ◽

Atomic Layer ◽

Transmission Electron ◽

Layer Deposition ◽

Transparent Windows ◽

First Time

This paper presents for the first time, the integration of ultra-thin (<10 nm) atomic layer deposition (ALD) aluminum oxide (Al2O3) membranes as electron transparent windows (ETWs) for transmission electron microscope (TEM) nanoreactor applications. The process was successfully implemented and tested in a TEM. ETWs with thicknesses down to 5 and 10 nm were used to image nanoparticles (NPs) in a 120 keV TEM and 200 keV TEM respectively.

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Microstructure and Interfaces of Ultra-Thin Epitaxial AlN Films Grown by Plasma-Enhanced Atomic Layer Deposition at Relatively Low Temperatures

Coatings ◽

10.3390/coatings11040482 ◽

2021 ◽

Vol 11 (4) ◽

pp. 482

Author(s):

Ramasis Goswami ◽

Syed Qadri ◽

Neeraj Nepal ◽

Charles Eddy, Jr.

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Atomic Layer ◽

Hexagonal Structure ◽

Cubic Phase ◽

Orientation Relation ◽

Transmission Electron ◽

Layer Deposition ◽

Aln Film ◽

Phase Transmission

We demonstrate the growth of ultra-thin AlN films on Si (111) and on a GaN/sapphire (0001) substrate using atomic layer epitaxy in the temperature range of 360 to 420 °C. Transmission electron microscopy and X-ray diffraction were used to characterize the interfaces, fine scale microstructure, and the crystalline quality of thin films. Films were deposited epitaxily on Si (111) with a hexagonal structure, while on the GaN/sapphire (0001) substrate, the AlN film is epitaxial and has been deposited in a metastable zinc-blende cubic phase. Transmission electron microscopy reveals that the interface is not sharp, containing an intermixing layer with cubic AlN. We show that the substrate, particularly the strain, plays a major role in dictating the crystal structure of AlN. The strain, estimated in the observed orientation relation, is significantly lower for cubic AlN on hexagonal GaN as compared to the hexagonal AlN on hexagonal GaN. On the Si (111) substrate, on the other hand, the strain in the observed orientation relation is 0.8% for hexagonal AlN, which is substantially lower than the strain estimated for the cubic AlN on Si(111).

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Preparation of Al2O3 and AlN Nanotubes by Atomic Layer Deposition

MRS Proceedings ◽

10.1557/opl.2012.38 ◽

2012 ◽

Vol 1408 ◽

Author(s):

Cagla Ozgit ◽

Fatma Kayaci ◽

Inci Donmez ◽

Engin Cagatay ◽

Tamer Uyar ◽

...

Keyword(s):

Electron Microscopy ◽

Atomic Layer Deposition ◽

Photoelectron Spectroscopy ◽

Atomic Layer ◽

X Ray ◽

Selected Area Electron Diffraction ◽

Transmission Electron ◽

Layer Deposition ◽

High Resolution Tem ◽

Uniform Wall

ABSTRACTAl2O3 and AlN nanotubes were fabricated by depositing conformal thin films via atomic layer deposition (ALD) on electrospun nylon 66 (PA66) nanofiber templates. Depositions were carried out at 200°C, using trimethylaluminum (TMAl), water (H2O), and ammonia (NH3) as the aluminum, oxygen, and nitrogen precursors, respectively. Deposition rates of Al2O3 and AlN at this temperature were ∼1.05 and 0.86 Å/cycle. After the depositions, Al2O3- and AlN-coated nanofibers were calcinated at 500°C for 2 h in order to remove organic components. Nanotubes were characterized by using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). AlN nanotubes were polycrystalline as determined by high resolution TEM (HR-TEM) and selected area electron diffraction (SAED). TEM images of all the samples reported in this study indicated uniform wall thicknesses.

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Growth of Nano-Needles of Manganese(IV) Oxide by Atomic Layer Deposition

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2008.18154 ◽

2008 ◽

Vol 8 (2) ◽

pp. 1003-1011

Author(s):

Ola Nilsen ◽

Steinar Foss ◽

Arne Kjekshus ◽

Helmer Fjellvåg

Keyword(s):

Electron Microscopy ◽

Thin Films ◽

Atomic Layer Deposition ◽

Atomic Layer ◽

Soda Lime ◽

Soda Lime Glass ◽

Deposition Technique ◽

Transmission Electron ◽

Layer Deposition ◽

Atomic Layer Deposition Technique

Needles of manganese(IV) oxide in the nanometer range have been synthesised using the atomic layer deposition technique. Traditionally the atomic layer deposition technique is used for the fabrication of thin films, however, we find that needles of β-MnO2 are formed when manganese(IV) oxide is deposited as relatively thick (ca. 800 nm) thin films on substrates of α-Al2O3 [(001) and (012) oriented]. There is no formation of needles when the film is deposited on substrates such as Si(100) or soda lime glass. The film is formed using Mn(thd)3 (Hthd = 2,2,6,6-tetramethylheptane-3,5-dione) and ozone as precursors. While thin films (ca. 100 nm) consist of ε′-MnO2,22, 23 the same process applied to thicker films results in the formation of nano-needles of β-MnO2. These needles of β-MnO2 have dimensions ranging from approximately 1.5 μm at the base down to very sharp tips. The nano-needles and the bulk of the films have been analysed by atomic force microscopy, scanning electron microscopy, X-ray diffraction, and transmission electron microscopy.

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Use of a New Non-Pyrophoric Liquid Aluminum Precursor for Atomic Layer Deposition

Materials ◽

10.3390/ma12091429 ◽

2019 ◽

Vol 12 (9) ◽

pp. 1429 ◽

Cited By ~ 2

Author(s):

Xueming Xia ◽

Alaric Taylor ◽

Yifan Zhao ◽

Stefan Guldin ◽

Chris Blackman

Keyword(s):

Electron Microscopy ◽

Atomic Layer Deposition ◽

Vapor Deposition ◽

Liquid Aluminum ◽

Chemical Vapor ◽

Atomic Layer ◽

Transmission Electron ◽

Layer Deposition ◽

Quartz Substrates ◽

Optimized Conditions

An Al2O3 thin film has been grown by vapor deposition using different Al precursors. The most commonly used precursor is trimethylaluminum, which is highly reactive and pyrophoric. In the purpose of searching for a more ideal Al source, the non-pyrophoric aluminum tri-sec-butoxide ([Al(OsBu)3], ATSB) was introduced as a novel precursor for atomic layer deposition (ALD). After demonstrating the deposition of Al2O3 via chemical vapor deposition (CVD) and ‘pulsed CVD’ routes, the use of ATSB in an atomic layer deposition (ALD)-like process was investigated and optimized to achieve self-limiting growth. The films were characterized using spectral reflectance, ellipsometry and UV-Vis before their composition was studied. The growth rate of Al2O3 via the ALD-like process was consistently 0.12 nm/cycle on glass, silicon and quartz substrates under the optimized conditions. Scanning electron microscopy and transmission electron microscopy images of the ALD-deposited Al2O3 films deposited on complex nanostructures demonstrated the conformity, uniformity and good thickness control of these films, suggesting a potential of being used as the protection layer in photoelectrochemical water splitting.

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