Microstructural Effects in the Thermochromic Behavior of VO2/Al/Si Thin Film Heterostructures

2000 ◽  
Vol 654 ◽  
Author(s):  
K. Dovidenko ◽  
S. Beasor ◽  
A. Topol ◽  
H. Efstathiadis ◽  
S. Oktyabrsky ◽  
...  
Keyword(s):  
Thin Film ◽  
Phase Transition ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Chemical Properties ◽  
Chemical Vapor ◽  
Metal Insulator ◽  
Transmission Electron ◽  
Composition And Structure ◽  
Insulator Phase Transition

AbstractWe present the results of detailed chemical and structural characterization of the VO2/Al/Si(100) thin film heterostructures fabricated by chemical vapor deposition and physical vapor deposition methods. The presence of the thermochromic behavior in the VO2 layer around 68°C and its correlation with the layer composition and structure are discussed. The study compares the structural and chemical properties of the two types of thin VO2 layers: one which exhibits a metal-insulator phase transition around 68°C, and another which fails to undergo the temperature-induced transition. The study of interfaces was carried out by transmission electron microscopy, and showed the existence of an aluminum oxide interfacial layer between VO2 and Al for the samples with the metal-insulator phase transition. The smooth VO2/Al interface and the presence of more than one VO2 monoclinic polytypes were observed for the CVD films exhibiting no phase transition.

scholarly journals CVD and PVD coating process modelling by using artificial neural networks

2012 ◽  
Vol 1 (1) ◽  
pp. 46 ◽  
Author(s):  
Amir Mahyar Khorasani ◽  
Mohammad Reza Solymany yazdi ◽  
Mehdi Faraji ◽  
Alex Kootsookos
Keyword(s):  
Thin Film ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Chemical Vapor ◽  
Film Coating ◽  
Deposition Process ◽  
Thin Film Coating ◽  
Mlp Neural Network ◽  
Titanium Thin Film ◽  
Pvd Coating

Thin-film coating plays a prominent role on the manufacture of many industrial devices. Coating can increase material performance due to the deposition process. Having adequate and precise model that can predict the hardness of PVD and CVD processes is so helpful for manufacturers and engineers to choose suitable parameters in order to obtain the best hardness and decreasing cost and time of industrial productions. This paper proposes the estimation of hardness of titanium thin-film layers as protective industrial tools by using multi-layer perceptron (MLP) neural network. Based on the experimental data that was obtained during the process of chemical vapor deposition (CVD) and physical vapor deposition (PVD), the modeling of the coating variables for predicting hardness of titanium thin-film layers, is performed. Then, the obtained results are experimentally verified and very accurate outcomes had been attained.

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 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.

Segregation of aluminum in Si and SiO2 films deposited by plasma-enhanced chemical vapor deposition in fabrication of low-temperature poly Si thin-film transitor

2003 ◽  
Vol 18 (4) ◽  
pp. 973-978 ◽  
Author(s):  
U. C. Oh ◽  
Kwang Nam Kim ◽  
Sung Chul Kim ◽  
Hye Dong Kim ◽  
Ho Kyoon Chung
Keyword(s):  
Thin Film ◽  
Chemical Vapor Deposition ◽  
Low Temperature ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Transmission Electron Microscopy Image ◽  
Impurity Level ◽  
Transmission Electron ◽  
Microscopy Image ◽  
Si Thin Film

Metal contamination in Si and SiO2 films deposited by plasma-enhanced chemical vapor deposition (PECVD) in the fabrication of low-temperature poly Si thin-film transitor was investigated. Aluminum was the major metal impurity to have the highest concentration. Segregation of Al was always observed in the films deposited at temperatures above 400 °C. The impurity level in the segregated region was 1018 ∼ 1020 atoms/cm3 for Al, while the concentration in matrix was about 1016 atoms/cm3. From the transmission electron microscopy image, the Al segregated region contains small-size Al precipitates. Although the Al impurity level of 1016 atoms/cm3 did not cause any serious degradation of device performance, the level of 1018 atom/cm3 and higher can induce a fatal degradation of the threshold voltage. This study revealed that the Al originated from the PECVD chamber, carbon precipitates provided the preferred sites for Al precipitates, and the solubility and diffusivity of Al in Si accelerated the segregation of Al.

Prolonging the Lifetime of PEEK Packages for Implantable Electronic Devices Using Commercially Available Vacuum Thin Film Coatings

2014 ◽  
Vol 11 (3) ◽  
pp. 128-136
Author(s):  
Nathaniel Dahan ◽  
Nick Donaldson ◽  
Stephen Taylor ◽  
Nuno Sereno
Keyword(s):  
Thin Film ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
High Surface ◽  
Chemical Vapor ◽  
Atomic Layer ◽  
Film Coating ◽  
Internal Cavity ◽  
Thin Film Coatings ◽  
Uniform Wall

For short term applications (less than three years), it may be possible to replace traditional long term packaging materials such as titanium with a biocompatible polymer such as PEEK. This paper investigates the use of commercially available thin films to decrease the water vapor permeation rate through the walls of a PEEK package. It was found that most physical vapor deposition (PVD) and plasma assisted chemical vapor deposition (PaCVD) coatings tested did not provide a significant improvement in lifetime, due to the porosity of the films produced. This is mostly linked to the morphology of the films (i.e., growth in columns which are poorly bonded together, creating a porous structure) and is exacerbated by the high surface roughness of the machined substrates. Applying a lacquer before coating reduces this effect significantly, and we found that the time constant of our coated packages was improved by a factor of 2.3. Based on the findings of our group's previous work and this paper, the maximum achievable lifetime of PEEK packages with a thin film coating and desiccant is presented. As an example, a coated cylindrical PEEK package (using atomic layer deposition, ALD) with a uniform wall thickness of 2 mm, an internal cavity size of 1.5 cm3, filled with 20% of desiccant, has a lifetime of 18.8 mo (27.2 mo with 30% of desiccant). This would be sufficient for a range of applications and provide a cheaper and more versatile packaging alternative to traditional packages.

Magnetron Sputtering for Low-temperature Deposition of CdTe-based Photovoltaics

2003 ◽  
Vol 763 ◽  
Author(s):  
Alvin D. Compaan
Keyword(s):  
Thin Film ◽  
Magnetron Sputtering ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
High Efficiency ◽  
Chemical Vapor ◽  
Rf Magnetron Sputtering ◽  
Polycrystalline Thin Film ◽  
Thin Film Semiconductors ◽  
Temperature Deposition

AbstractAlthough the deposition over large areas of polycrystalline thin-film semiconductors such as CdTe is possible by a variety of methods including close spaced sublimation, vapor transport deposition, physical vapor deposition, organometallic chemical vapor deposition, and electrodeposition, the use of a plasma-based method such as magnetron sputtering can have significant advantages. In this paper I review recent results from our group in the fabrication of CdS/CdTe cells using rf magnetron sputtering and discuss some of the advantages that appear possible from the use of sputtering methods in this class of materials. Some of these advantages are particularly relevant as the polycrystalline thin-film community address issues related to the challenges of fabricating high efficiency tandem cells with efficiencies over 25%. Recently we have achieved: improvements in sputtered cell performance with cells based on commercial SnO2:F as well as on substrates with our own sputtered ZnO:Al, progress in the use of reactive sputtering for the deposition of oxygen alloys of CdS and N-doped layers of ZnTe, and progress in the sputtering of wider and narrower bandgap alloys of CdTe with Zn, Mn, and Hg. Details of the sputtering process and some of the recent achievements are discussed below.

scholarly journals Application of Physical Vapor Deposition in Textile Industry

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Pamela Miśkiewicz ◽  
Iwona Frydrych ◽  
Agnieszka Cichocka
Keyword(s):  
Vapor Deposition ◽  
Textile Industry ◽  
Physical Vapor Deposition ◽  
Chemical Properties ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Knitted Fabrics ◽  
Textile Materials ◽  
Almost All ◽  
Physical And Chemical

AbstractCurrently, scientists are striving to produce innovative textile materials characterized by special properties. Therefore, attempts have been made to use physical and chemical vapor deposition techniques to modify the surface of textile materials, i.e., nonwovens, fabrics, and knitted fabrics. By using these techniques for modifying the basic materials, researchers have obtained textiles with novel properties, which are used in shielding materials, textronics, or clothing, as well as in specialized accessories. The PVD process can be applied for almost all materials. The physical vapor deposition process allows for obtaining layers of different thicknesses and with various physical and chemical properties. This article is a review of the latest state of the art on the use of various methods of physical vapor deposition in textiles destined for different purposes.

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