Rapid Photo-Thermal Chemical Vapor Deposition of Amorphous Carbon From Diiodomethane

1999 ◽  
Vol 593 ◽  
Author(s):  
M. Lindstam ◽  
M. Boman ◽  
K. Piglmayer

ABSTRACTA novel approach to deposit amorphous carbon from the precursor CH2I2 at low cost and high efficiency is reported. The combination of thermal and quantum photo effects shows new interesting growth behaviour. The radiation of a halogen-lamp was used to heat the substrate material and to split photolytically the precursor molecules above the substrate surface. The deposition process was investigated as a function of lamp power, gas phase partial pressures and substrate materials. The films were analysed by Raman spectroscopy, scanning electron microscopy, energy dispersive x-ray spectroscopy, x-ray photon spectroscopy, transmission electron microscopy and atomic force microscopy.

2001 ◽  
Vol 16 (11) ◽  
pp. 3133-3138 ◽  
Author(s):  
Jun Liu ◽  
X. Zhang ◽  
Yingjiu Zhang ◽  
Rongrui He ◽  
Jing Zhu

A relatively low-cost, high-efficiency method is reported to synthesize AlN nanowires, using carbon nanotubes as templates. The AlN nanowires were fabricated at 1100 °C, for 60 min. The diameters of the product could be roughly controlled by the sizes of carbon nanotubes selected as starting materials. The AlN nanowires obtained were among the thinnest ever known. X-ray diffraction, selected-area diffraction, energy dispersive spectroscopy, and high-resolution transmission electron microscopy, etc. were employed to characterize the products, which were found to be single crystals with some defects. The axes of the nanowires are normal to {1010} crystal planes. A new synthesis mechanism is proposed.


1990 ◽  
Vol 202 ◽  
Author(s):  
Garth B. Freeman ◽  
Woo Y. Lee ◽  
W. J. Lackey ◽  
John A. Hanigofsky ◽  
Karren More

ABSTRACTThis paper discusses the variation in microstructures encountered during the separate depositions of boron nitride (BN) and aluminum nitride (A1N) as well as during the codeposition of BNߝA1N dispersed phase ceramic coatings. This combination was chosen in order to take advantage of the self lubricating properties of hexagonal BN along with the hard, erosion resistance of A1N. Films were characterized using scanning and transmission electron microscopy (SEM and TEM), x-ray photoelectron spectroscopy (XPS), and x-ray diffraction (XRD).A range of coating microstructures are possible depending on the conditions of deposition. The best films produced, in terms of hardness, density, and tenacity, were a fine mixture of turbostratic BN and preferentially oriented A1N whiskers aligned with the whisker axis perpendicular to the substrate surface as seen by both electron microscopy and x-ray diffraction.


2011 ◽  
Vol 306-307 ◽  
pp. 1364-1368 ◽  
Author(s):  
Qian Zhang ◽  
Li Feng Dong

A series of techniques, including field emission scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, and energy dispersive X-ray spectroscopy were employed to investigate three types of Y-shaped carbon fibers that were synthesized by the thermal decomposition of acetylene using an atmospheric pressure catalytic chemical vapor deposition process and copper tartrate as a catalyst precursor. On the basis of electron microscopy analysis, we propose that the simultaneous growth of three pieces of carbon fibers on the same copper catalyst particle results in the formation of Y-shaped carbon fibers. When several copper catalyst particles became positioned in a stratified arrangement, other types of Y-shaped carbon fibers were obtained. Our study indicates that the morphology of various Y-shaped carbon fibers can be controlled by tailoring the configuration of the copper catalyst particles used to generate them.


Author(s):  
D.P. Malta ◽  
S.A. Willard ◽  
R.A. Rudder ◽  
G.C. Hudson ◽  
J.B. Posthill ◽  
...  

Semiconducting diamond films have the potential for use as a material in which to build active electronic devices capable of operating at high temperatures or in high radiation environments. A major goal of current device-related diamond research is to achieve a high quality epitaxial film on an inexpensive, readily available, non-native substrate. One step in the process of achieving this goal is understanding the nucleation and growth processes of diamond films on diamond substrates. Electron microscopy has already proven invaluable for assessing polycrystalline diamond films grown on nonnative surfaces.The quality of the grown diamond film depends on several factors, one of which is the quality of the diamond substrate. Substrates commercially available today have often been found to have scratched surfaces resulting from the polishing process (Fig. 1a). Electron beam-induced current (EBIC) imaging shows that electrically active sub-surface defects can be present to a large degree (Fig. 1c). Growth of homoepitaxial diamond films by rf plasma-enhanced chemical vapor deposition (PECVD) has been found to planarize the scratched substrate surface (Fig. 1b).


1990 ◽  
Vol 5 (6) ◽  
pp. 1169-1175 ◽  
Author(s):  
A. D. Berry ◽  
R. T. Holm ◽  
M. Fatemi ◽  
D. K. Gaskill

Films containing the metals copper, yttrium, calcium, strontium, barium, and bismuth were grown by organometallic chemical vapor deposition (OMCVD). Depositions were carried out at atmospheric pressure in an oxygen-rich environment using metal beta-diketonates and triphenylbismuth. The films were characterized by Auger electron spectroscopy, Nomarski and scanning electron microscopy, and x-ray diffraction. The results show that films containing yttrium consisted of Y2O3 with a small amount of carbidic carbon, those with copper and bismuth were mixtures of oxides with no detectable carbon, and those with calcium, strontium, and barium contained carbonates. Use of a partially fluorinated barium beta-diketonate gave films of BaF2 with small amounts of BaCO3.


1986 ◽  
Vol 77 ◽  
Author(s):  
Mary Beth Stearns ◽  
Amanda K. Petford-Long ◽  
C.-H. Chang ◽  
D. G. Stearns ◽  
N. M. Ceglio ◽  
...  

ABSTRACTThe technique of high resolution electron microscopy has been used to examine the structure of several multilayer systems (MLS) on an atomic scale. Mo/Si multilayers, in use in a number of x-ray optical element applications, and Mo/Si multilayers, of interest because of their magnetic properties, have been imaged in cross-section. Layer thicknesses, flatness and smoothness have been analysed: the layer width can vary by up to 0.6nm from the average value, and the layer flatness depends on the quality of the substrate surface for amorphous MLS, and on the details of the crystalline growth for the crystalline materials. The degree of crystallinity and the crystal orientation within the layers have also been investigated. In both cases, the high-Z layers are predominantly crystalline and the Si layers appear amorphous. Amorphous interfacial regions are visible between the Mo and Si layers, and crystalline cobalt suicide interfacial regions between the Co and Si layers. Using the structural measurements obtained from the HREM results, theoretical x-ray reflectivity behaviour has been calculated. It fits the experimental data very well.


1995 ◽  
Vol 396 ◽  
Author(s):  
P.G. Blauner ◽  
A. Wagner

AbstractThe ion beam induced metal deposition processes now employed by commercial focused ion beam (FIB) tools all demonstrate less than optimal characteristics for use in circuit repair, a major application of these tools. In particular, the processes have low efficiencies, the metals produced have poor conductivity, and some form of clean up is generally required to remove excess material surrounding the repair site. The gold deposition process developed for x-ray mask repair, in contrast, exhibits efficiencies 10-50 times higher with significantly less material deposited in unwanted areas. Unfortunately, the conductivity of the gold is even poorer than that of materials now used for FIB circuit repair.In this paper, an annealing step which improves the conductivity of FIB deposited Au is described. Results are presented demonstrating resistivities of 5-15 μΩ-cm while maintaining the high efficiency of the gold deposition process. The suitability of the process for use in FIB circuit repair is discussed.


2008 ◽  
Vol 40 (2) ◽  
pp. 147-154
Author(s):  
A. Chekhovskii ◽  
T. Tomila ◽  
A. Ragulya ◽  
I. Timofeeva ◽  
A. Ivanchuk ◽  
...  

Powded CxNy coatings were deposited from acetonitrile on Ni, Si, and C surfaces at a voltage 500-2000 V by the electrochemical method. Electrolysis products were analyzed by IR spectroscopy, X-ray phase analysis and electron microscopy. According to FTIR data, at frequencies 1370 and 1530 cm-1, absorption bands characteristic for stretching C-N and C=N oscillations are observed. The obtained results indicate that the deposition process occurs in a different manner in each specific case, i.e., the kinetics of the electrode depends on the electrode material (Ni, Si, and C).


1999 ◽  
Vol 581 ◽  
Author(s):  
Q. Wei ◽  
C.M. Lieber

ABSTRACTA solution-based synthesis route was developed to produce large quantities of MgO nanorods. Hydrated basic magnesium chloride, which has needle-like crystal structure, was used as a precursor. A subsequent two-step transformation process with magnesium hydroxide as an intermediate product was used to preserve the morphology of the precursor to yield magnesium oxide nanorods. Scanning electron microscopy, powder X-ray diffraction and energy dispersive X-ray spectroscopy show that the products are very pure (>95%) crystalline MgO nanorods with diameters from 40 nm to 200 nm and lengths 10 microns or longer. High-resolution transmission electron microscopy and electron diffraction further reveal that these MgO nanorods are single crystals and that the rod axis is along the <110> crystal direction. A model for the structural transformation from hydrated basic magnesium chloride to magnesium oxide has been developed and compared to our experimental results. This solution-based process can be easily scaled-up, and is a low-cost source of pure magnesium oxide nanorods needed in many industrial applications, for example, as reinforcing agents in matrix composites and as flux-pinning centers in high-TC superconductors.


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