scholarly journals Growth and Mechanism of MoS2Nanoflowers with Ultrathin Nanosheets

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Yifei Guo ◽  
Xiuli Fu ◽  
Zhijian Peng
Keyword(s):  
Electron Microscopy ◽  
Vapor Deposition ◽  
Optoelectronic Devices ◽  
Chemical Vapor ◽  
Silicon Substrates ◽  
Optical And Electrical Properties ◽  
Two Dimensional ◽  
Ultrathin Nanosheets ◽  
Transmission Electron ◽  
Composition And Structure

Two-dimensional molybdenum disulfide (MoS2) with few layers, due to their excellent optical and electrical properties, has great potential for applications in electronic and optoelectronic devices. In this work, flower-like MoS2nanostructures with ultrathin nanosheets (petals) were successfully deposited onto silicon substrates by a facile process based on chemical vapor deposition via using MoO3and S powders as starting materials. Their composition and structure were explored by field emission scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and photoluminescence. The reported nanoflowers vertically and separately stood on the substrates, consisting of several bonded MoS2nanosheets with a thickness of 10–30 nm and high crystallinity. On the basis of these results, a growth mechanism for the MoS2nanoflowers was proposed.

Aligned Carbon Nanotubes Via Microwave Plasma Enhanced Chemical Vapor Deposition

1999 ◽  
Vol 593 ◽  
Author(s):  
H. Cui ◽  
D. Palmer ◽  
O. Zhou ◽  
B. R. Stoner
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Silicon Substrates ◽  
Multi Wall Carbon Nanotubes ◽  
Field Emission Properties ◽  
Transmission Electron

ABSTRACTAligned multi-wall carbon nanotubes have been grown on silicon substrates by microwave plasma enhanced chemical vapor deposition using methane/ammonia mixtures. The concentration ratio of methane/ammonia in addition to substrate temperature was varied. The morphology, structure and alignment of carbon nanotubes were studied by scanning electron microscopy and transmission electron microscopy. Both concentric hollow and bamboo-type multi-wall carbon nanotubes were observed. Growth rate, size distribution, alignment, morphology, and structure of carbon nanotubes changed with methane/ammonia ratio and growth temperature. Preliminary results on field emission properties are also presented.

Transmission Electron Microscopy (TEM) Specimen Preparation Technique using Focused Ion Beam (FIB): Application to Material Characterization of Chemical Vapor Deposition of Tungsten (W) and Tungsten Silicides (WSix)

1997 ◽  
Author(s):  
K. Doong ◽  
J.-M. Fu ◽  
Y.-C. Huang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Chemical Vapor ◽  
Specimen Preparation ◽  
Preparation Technique ◽  
Transmission Electron

Abstract The specimen preparation technique using focused ion beam (FIB) to generate cross-sectional transmission electron microscopy (XTEM) samples of chemical vapor deposition (CVD) of Tungsten-plug (W-plug) and Tungsten Silicides (WSix) was studied. Using the combination method including two axes tilting[l], gas enhanced focused ion beam milling[2] and sacrificial metal coating on both sides of electron transmission membrane[3], it was possible to prepare a sample with minimal thickness (less than 1000 A) to get high spatial resolution in TEM observation. Based on this novel thinning technique, some applications such as XTEM observation of W-plug with different aspect ratio (I - 6), and the grain structure of CVD W-plug and CVD WSix were done. Also the problems and artifacts of XTEM sample preparation of high Z-factor material such as CVD W-plug and CVD WSix were given and the ways to avoid or minimize them were suggested.

Effectiveness and Reliability of Metal Diffusion Barriers for Copper Interconnects

1995 ◽  
Vol 403 ◽  
Author(s):  
G. Bai ◽  
S. Wittenbrock ◽  
V. Ochoa ◽  
R. Villasol ◽  
C. Chiang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Chemical Vapor ◽  
Diffusion Barriers ◽  
Copper Interconnects ◽  
Time To Failure ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

AbstractCu has two advantages over Al for sub-quarter micron interconnect application: (1) higher conductivity and (2) improved electromigration reliability. However, Cu diffuses quickly in SiO2and Si, and must be encapsulated. Polycrystalline films of Physical Vapor Deposition (PVD) Ta, W, Mo, TiN, and Metal-Organo Chemical Vapor Deposition (MOCVD) TiN and Ti-Si-N have been evaluated as Cu diffusion barriers using electrically biased-thermal-stressing tests. Barrier effectiveness of these thin films were correlated with their physical properties from Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM), Secondary Electron Microscopy (SEM), and Auger Electron Spectroscopy (AES) analysis. The barrier failure is dominated by “micro-defects” in the barrier film that serve as easy pathways for Cu diffusion. An ideal barrier system should be free of such micro-defects (e.g., amorphous Ti-Si-N and annealed Ta). The median-time-to-failure (MTTF) of a Ta barrier (30 nm) has been measured at different bias electrical fields and stressing temperatures, and the extrapolated MTTF of such a barrier is > 100 year at an operating condition of 200C and 0.1 MV/cm.

Understanding the Growth Mechanisms of Tin Oxide Nanowires by Chemical Vapor Deposition

2021 ◽  
Vol 21 (4) ◽  
pp. 2538-2544
Author(s):  
Nguyen Minh Hieu ◽  
Nguyen Hoang Hai ◽  
Mai Anh Tuan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Chemical Mapping ◽  
X Ray Diffraction ◽  
Lattice Constants ◽  
Transmission Electron ◽  
Scanning Transmission

Tin oxides nanowires were prepared by chemical vapor deposition using shadow mask. X-ray diffraction indicated that the products were tetragonal having crystalline structure with lattice constants a = 0.474 nm and c = 0.318 nm. The high-resolution transmission electron microscopy revealed that inter planar spacing is 0.25 nm. The results chemical mapping in scanning transmission electron microscopy so that the two elements of Oxygen and Tin are distributed very homogeneously in nanowires and exhibit no apparent elements separation. A bottom-up mechanism for SnO2 growth process has been proposed to explain the morphology of SnO2 nanowires.

scholarly journals Growth of U-Shaped Graphene Domains on Copper Foil by Chemical Vapor Deposition

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1887
Author(s):  
Ming Pan ◽  
Chen Wang ◽  
Hua-Fei Li ◽  
Ning Xie ◽  
Ping Wu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Growth Parameters ◽  
Copper Substrate ◽  
Chemical Vapor ◽  
Morphology Evolution ◽  
Force Microscopy ◽  
Smooth Edge ◽  
Transmission Electron

U-shaped graphene domains have been prepared on a copper substrate by chemical vapor deposition (CVD), which can be precisely tuned for the shape of graphene domains by optimizing the growth parameters. The U-shaped graphene is characterized by using scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), and Raman. These show that the U-shaped graphene has a smooth edge, which is beneficial to the seamless stitching of adjacent graphene domains. We also studied the morphology evolution of graphene by varying the flow rate of hydrogen. These findings are more conducive to the study of morphology evolution, nucleation, and growth of graphene domains on the copper substrate.

Silicon homoepitaxy using tantalum-filament hot-wire chemical vapor deposition

2005 ◽  
Vol 862 ◽  
Author(s):  
Charles W. Teplin ◽  
Eugene Iwaniczko ◽  
Kim M. Jones ◽  
Robert Reedy ◽  
Bobby To ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Secondary Ion Mass Spectrometry ◽  
Chemical Vapor ◽  
Silicon Wafers ◽  
Silicon Films ◽  
Hot Wire ◽  
Transmission Electron ◽  
Increasing Temperature

AbstractWe have studied silicon films grown epitaxially on silicon wafers using hot-wire chemical vapor deposition (HWCVD) with a tantalum filament. Silicon films were grown on (100)-oriented hydrogen terminated silicon wafers at temperatures from 175°C to 480°C, using a Ta filament 5 cm from the substrate to decompose pure SiH4 gas. The progression of epitaxy was monitored using real-time spectroscopic ellipsometry (RTSE). Analysis using RTSE, transmission electron microscopy (TEM), and scanning electron microscopy shows that at a characteristic thickness, hepi all of the films break down into a-Si:H cones. Below 380°C, both hepi and the thickness of the transition to pure a-Si:H increase with increasing temperature. Above 380°C, hepi was not observed to increase further but TEM images show fewer defects in the epitaxial regions. Secondary ion-mass spectrometry shows that the oxygen concentration remains nearly constant during growth (<1018 cm-3). The hydrogen concentration is found to increase substantially with film thickness from 5·1018 to 5·1019 cm-3, likely due to the incorporation of hydrogen into the a-Si:H cones that grow after the breakdown of epitaxy.

Controlled Growth of Carbon Spheres by Chemical Vapor Deposition Based on Anodic Aluminum Oxide Nano-Template

2012 ◽  
Vol 184-185 ◽  
pp. 924-927
Author(s):  
Lei Shan Chen ◽  
Cun Jing Wang ◽  
Gai Rong Chen
Keyword(s):  
Electron Microscopy ◽  
Vapor Deposition ◽  
Anodic Aluminum Oxide ◽  
Chemical Vapor ◽  
Average Diameter ◽  
Carbon Spheres ◽  
Aao Template ◽  
Graphene Layers ◽  
Anodic Aluminum ◽  
Transmission Electron

The reactions were carried out by decomposing acetylene at 1000 °C in a two-stage furnace system for 10 min. In the first furnace no catalyst was placed and an AAO template with the average diameter about 50 nm was placed in the second furnace whose temperature was designed to be 500 °C, 600 °C and 700 °C. The samples were characterized by scanning electron microscopy and high resolution transmission electron microscopy. The results show that carbon spheres with average diameter about 50 nm on the AAO template surface were obtained when the temperature of the second furnace was designed to be 700 °C. These carbon spheres are composed of unclosed graphene layers with an interlayer distance of 0.33–0.35 nm between the layers.

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