Poly(meta-phenylene isophthalamide) nanofibers: Coating and post processing

2002 ◽  
Vol 17 (12) ◽  
pp. 3206-3212 ◽  
Author(s):  
Wenxia Liu ◽  
Matthew Graham ◽  
Edward A. Evans ◽  
Darrell H. Reneker
Keyword(s):  
Electron Microscopy ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Chemical Vapor ◽  
Electrospun Nanofibers ◽  
Post Processing ◽  
Good Thermal Stability ◽  
Nanoscale Structures ◽  
Transmission Electron ◽  
Deposited Films

Electrospun nanofibers have applications in the areas of filtration, composites, biomaterials, and electronics. Controlling the surface properties of these nanofibers is important for many applications. Nanofibers can also be used as unique substrates for observing the growth of deposited films and creating nanoscale structures. In this work, electrospun poly(meta-phenylene isophthalamide) (MPD-I) nanofibers were used as substrates for creating nanoscale structures out of carbon-based materials and metals. MPD-I was used because it can be electrospun into nanofibers with diameters smaller than 10 nm and it has good thermal stability. MPD-I nanofibers were coated with carbon, copper, and aluminum using plasma enhanced chemical vapor deposition and physical vapor deposition methods. Some of the aluminum-coated nanofibers were then converted into nanotubes. Transmission electron microscopy was used to determine the thickness, uniformity, and grain size of the coatings on the fibers and the nanotubes.

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.

scholarly journals Structure and Mechanical Properties of PVD and CVD TiAlSiN Coatings Deposited on Cemented Carbide

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 598
Author(s):  
Liying Wu ◽  
Lianchang Qiu ◽  
Yong Du ◽  
Fangfang Zeng ◽  
Qiang Lu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Energy Dispersive Spectrometer ◽  
Chemical Vapor ◽  
Cemented Carbide ◽  
Transmission Electron ◽  
Pressure Chemical

This work reports the results of our investigation of the structure and mechanical properties of physical vapor deposition (PVD) and chemical vapor deposition (CVD) TiAlSiN coatings deposited on cemented carbide substrates. For the first time, a novel nanocomposite of Ti0.13Al0.85Si0.02N coating deposited from TiCl4-AlCl3-SiCl4-NH3-H2 gas precursors was prepared by low pressure chemical vapor deposition (LPCVD) at 780 °C and a pressure of 60 mbar, while PVD Ti0.31Al0.60Si0.09N coating was prepared using the arc ion plating method. The investigation results including morphology, microstructure, chemical composition, phase component, and hardness were carried out by scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS), transmission electron microscopy (TEM), X-ray diffraction (XRD), and nano-indentator. TEM results revealed that both PVD and CVD TiAlSiN coatings consisted of nanocrystalline embedded in SiNx amorphous. The nanohardness of CVD Ti0.13Al0.85Si0.02N coating obtained in this work was 31.7 ± 1.4 GPa, which was 35% higher than that of the PVD Ti0.31Al0.60Si0.09N coating.

scholarly journals Influence of duration time of CVD process on emissive properties of carbon nanotubes films

2015 ◽  
Vol 33 (1) ◽  
pp. 36-46
Author(s):  
Izabela Stępinska ◽  
Mirosław Kozłowski ◽  
Joanna Radomska ◽  
Halina Wronka ◽  
Elżbieta Czerwosz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Electron Emission ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Chemical Vapor ◽  
Second Step ◽  
Step Method ◽  
Transmission Electron ◽  
Deposition Step

AbstractIn this paper various types of films made of carbon nanotubes (CNTs) are presented. These films were prepared on different substrates (Al2O3, Si n-type) by the two-step method. The two-step method consists of physical vapor deposition step, followed by chemical vapor deposition step (PVD/CVD). Parameters of PVD process were the same for all initial films, while the duration times of the second step - the CVD process, were different (15, 30 min.). Prepared films were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and field emission (FE) measurements. The I-E and F-N characteristics of electron emission were discussed in terms of various forms of CNT films. The value of threshold electric field ranged from few V/μm (for CNT dispersed rarely on the surface of the film deposited on Si) up to ~20 V/μm (for Al2O3 substrate).

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.

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.

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