Examining the crystal growth that influences the electronic device output from vertical arrays of ZnO nanowires

2014 ◽  
Vol 1659 ◽  
pp. 101-106
Author(s):  
Alex M. Lord ◽  
Michael B. Ward ◽  
Alex S. Walton ◽  
Jonathan Evans ◽  
Nathan Smith ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Focused Ion Beam ◽  
Electronic Device ◽  
Ion Beam ◽  
Electrical Contact ◽  
Zno Nanowires ◽  
Base Layer ◽  
Vertical Arrays ◽  
Growth Method ◽  
A Minor

ABSTRACTZnO nanowire (NW) arrays were examined with Transmission Electron Microscopy (TEM) in cross-section after preparation by Focused Ion Beam (FIB) milling. This technique revealed that ZnO nanowires grown using a Au catalyzed vapor technique typically have Au particles at the NW tips, and also randomly dispersed across the base crystal growth that joins adjacent NWs. It is shown the adjacent NWs and the combined base growth is one crystal structure which can be used as a back electrical contact making fabrication of vertical array devices possible. However, the base growth displays detrimental features such as embedded Au particles and lattice defects which can affect the electrical output through depletion regions and scattering centers. In an effort to overcome these problems we investigate a growth method that is nucleated through a minor alteration of the a-plane sapphire surface roughness via a weak chemical etch. Observations of various stages of the growth show the growth nucleates as separate nanoislands that grow in c-plane alignment with Sapphire (1-210), and as growth continues these islands meet and form a polycrystalline film. Further growth initiates nanowire growth and the formation of a single crystal base layer and NW structure that can cover several square millimeter’s. This allows high quality arrays that are relatively free from defects to be formed without any metals contamination and ready for further device processing.

scholarly journals The Relationships of Microscopic Evolution to Resistivity Variation of a FIB-Deposited Platinum Interconnector

Micromachines ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 588
Author(s):  
Chaorong Zhong ◽  
Ruijuan Qi ◽  
Yonghui Zheng ◽  
Yan Cheng ◽  
Wenxiong Song ◽  
...  
Keyword(s):  
Electron Beam ◽  
Focused Ion Beam ◽  
Spherical Aberration ◽  
Ion Beam ◽  
Electrical Contact ◽  
Heating Process ◽  
Comprehensive Understanding ◽  
Irreversible Damage ◽  
Resistivity Variation

Depositing platinum (Pt) interconnectors during the sample preparation process via a focused ion beam (FIB) system is an inescapable procedure for in situ transmission electron microscopy (TEM) investigations. To achieve good electrical contact and avoid irreversible damage in practical samples, the microscopic evolution mechanism of FIB-deposited Pt interconnectors need a more comprehensive understanding, though it is known that its resistivity could be affected by thermal annealing. In this work, an electron-beam FIB-deposited Pt interconnector was studied by advanced spherical aberration (Cs)-corrected TEM combined with an in situ heating and biasing system to clarify the relationship of microscopic evolution to resistivity variation. During the heating process, the Pt interconnector underwent crystallization, organic matter decomposition, Pt nanocrystal growth, grain connection, and conductive path formation, which are combined actions to cause several orders of magnitude of resistivity reduction. The comprehensive understanding of the microscopic evolution of FIB-deposited Pt material is beneficial, not only for optimizing the resistance performance of Pt as an interconnector, but also for understanding the role of C impurities with metal materials. For the purpose of wiring, annealed electron-beam (EB)-deposited Pt material can be recommended for use as an interconnector in devices for research purposes.

Ohmic Contact for Silicon Carbide by Carbon Nanotubes

2016 ◽  
Vol 858 ◽  
pp. 561-564 ◽  
Author(s):  
Masafumi Inaba ◽  
Kazuma Suzuki ◽  
Yu Hirano ◽  
Wataru Norimatsu ◽  
Michiko Kusunoki ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Silicon Carbide ◽  
Barrier Height ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Electrical Contact ◽  
Conductive Atomic Force Microscopy ◽  
Cover Layer ◽  
Force Microscopy ◽  
Surface Decomposition

The electrical contact properties of silicon carbide (SiC) and carbon nanotubes (CNTs) were measured by conductive atomic force microscopy (C-AFM). A CNT forest was synthesized by SiC surface decomposition. Trenches, which electrically separate the conduction area, were fabricated using a focused ion beam (FIB) without a cover layer, and the resistance of each island was measured by C-AFM. From the dependence of the resistance on the CNT forest island size, the contact resistance between the CNTs and the SiC substrate was measured. By varying the dopant density in the SiC substrate, the Schottky barrier height was evaluated to be ~0.5 eV. This is slightly higher than a previously reported result obtained from a similar setup with a metal covering the CNT forest. We assumed that the damaged region existed in the islands, which is due to the trench formation by the FIB. The commensurate barrier height was obtained with the length of the damaged region assumed to be ~3 μm. Here, we could estimate the resistivity of a CNT/SiC interface without a cover layer. This indicates that a CNT forest on SiC is useful as a brief contact electrode.

scholarly journals Characterization of 4H Silicon Carbide Films Grown by Solvent-Laser Heated Floating Zone

2012 ◽  
Vol 1433 ◽  
Author(s):  
Andrew A. Woodworth ◽  
Ali Sayir ◽  
Philip G. Neudeck ◽  
Balaji Raghothamachar ◽  
Michael Dudley
Keyword(s):  
Silicon Carbide ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Growth Front ◽  
Electrical Performance ◽  
Floating Zone ◽  
X Ray ◽  
Growth Method ◽  
Laser Heated

ABSTRACTCommercially available bulk silicon carbide (SiC) has a high number (>2000/cm2) of screw dislocations (SD) that have been linked to degradation of high-field power device electrical performance properties. Researchers at the NASA Glenn Research Center have proposed a method to mass-produce significantly higher quality bulk SiC. In order for this bulk growth method to become reality, growth of long single crystal SiC fibers must first be achieved. Therefore, a new growth method, Solvent-Laser Heated Floating Zone (Solvent-LHFZ), has been implemented. While some of the initial Solvent-LHFZ results have recently been reported, this paper focuses on further characterization of grown crystals and their growth fronts. To this end, secondary ion mass spectroscopy (SIMS) depth profiles, cross section analysis by focused ion beam (FIB) milling and mechanical polishing, and orientation and structural characterization by X-ray transmission Laue diffraction patterns and X-ray topography were used. Results paint a picture of a chaotic growth front, with Fe incorporation dependant on C concentration.

Modification of structure and optical property of ZnO nanowires by Ga ion beam

2009 ◽  
Vol 1201 ◽  
Author(s):  
Yao Cheng ◽  
Yao Liang ◽  
Ming Lei ◽  
Siu Kong Hark ◽  
Ning Wang
Keyword(s):  
Optical Property ◽  
Low Temperatures ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Green Emission ◽  
Zno Nanowires ◽  
Crystal Quality ◽  
Spectroscopy Study ◽  
Doped Zno ◽  
Ga Doping

AbstractBased on the focused ion beam (FIB) technology, we have prepared ZnO nanowires containing periodic nano-sized structures by an ultra thin Ga ion beam. ZnO nanowires can keep a good crystal quality after Ga ion bombardment. The cathodoluminescence (CL) spectroscopy study of the Ga-doped ZnO nanowires at low temperatures shows that the Ga doping effect can largely suppress the green emission that may mainly originate from the defects on the surfaces of ZnO nanowires.

scholarly journals In-cell quantitative structural imaging of phytoplankton using 3D electron microscopy

2020 ◽  
Author(s):  
Clarisse Uwizeye ◽  
Johan Decelle ◽  
Pierre-Henri Jouneau ◽  
Benoit Gallet ◽  
Jean-Baptiste Keck ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cell Biology ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Phytoplankton Diversity ◽  
Cellular Energy ◽  
Unicellular Eukaryotes ◽  
3D Electron Microscopy ◽  
Abiotic And Biotic Factors ◽  
A Minor

AbstractPhytoplankton is a minor fraction of the global biomass playing a major role in primary production and climate. Despite improved understanding of phytoplankton diversity and genomics, we lack nanoscale subcellular imaging approaches to understand their physiology and cell biology. Here, we present a complete Focused Ion Beam - Scanning Electron Microscopy (FIB-SEM) workflow (from sample preparation to image processing) to generate nanometric 3D phytoplankton models. Tomograms of entire cells, representatives of six ecologically-successful phytoplankton unicellular eukaryotes, were used for quantitative morphometric analysis. Besides lineage-specific cellular architectures, we observed common features related to cellular energy management: i) conserved cell-volume fractions occupied by the different organelles; ii) consistent plastid-mitochondria interactions, iii) constant volumetric ratios in these energy-producing organelles. We revealed detailed subcellular features related to chromatin organization and to biomineralization. Overall, this approach opens new perspectives to study phytoplankton acclimation responses to abiotic and biotic factors at a relevant biological scale.

Focused ion beam milling as a tool in crystal growth elucidation

2004 ◽  
Author(s):  
B HODNETT ◽  
M MIHOV ◽  
C CASHELL ◽  
L OMAHONY ◽  
D CORCORAN ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Focused Ion Beam Milling

scholarly journals Characterization of a Si-SiO2 Mixture Generated from SiO(g) and CO(g)

2019 ◽  
Vol 50 (6) ◽  
pp. 2667-2680 ◽  
Author(s):  
Andrea Broggi ◽  
Merete Tangstad ◽  
Eli Ringdalen
Keyword(s):  
Photoelectron Spectroscopy ◽  
Gas Flow ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Liquid Silicon ◽  
Inert Gas ◽  
Dissolved Carbon ◽  
Sic Particles ◽  
Transmission Electron ◽  
A Minor

Abstract The reaction between SiO(g) and CO(g) is a relevant intermediate reaction in the silicon production process. One of the products generated from this gas mixture is called by its color, brown condensate. In this paper, SiO(g) and CO(g) are produced from SiO2-SiC pellets. The reaction between the two gases occurred on SiC particles. Inert gas was injected at different flows. The SiC particles were collected, and the brown condensate deposited on them was characterized by electron probe microanalysis, X-ray photoelectron spectroscopy, and focused ion beam preparation samples for transmission electron microscope analysis. The brown condensate consists of a mixture of Si spheres embedded in a SiO2 matrix. The compound generates in the temperature range from 1400 °C to 1780 °C (1673 K to 2053 K), and in the SiO(g) partial pressure range between 0.534 and 0.742, depending on the inert gas flow. SiC crystallites are located at the Si-SiO2 interface. Carbides are believed to generate from the reaction between liquid silicon and CO(g). Carbides may also precipitate from reaction between dissolved carbon and liquid silicon, but to a minor extent. Both mechanisms are believed to happen above the melting point of silicon and in the softening range of silica.

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