Preparation of WSi2 by RTA Annealing of CVD-W thin Films

1995 ◽  
Vol 402 ◽  
Author(s):  
K. A. Gesheva ◽  
G. I. Stoyanov ◽  
D. S. Gogova ◽  
G. D. Beshkov

AbstractWsi2 films were prepared by rapid thermal annealing (RTA) in the temperature range of 800 -1400 °C for time durations of 15 sec -3 minutes. In some of the treatment experiments different gases were involved and a conclusion is made about the role of hydrogen favoring Wsi crystal phase growing at 800 °C. W films with thichnesses in the range 200 Å - 1000 Å were deposited on monocrystalline Si by pyrolitical decomposition of W(CO)6 in CVD reactor at atmospheric pressure and argon atmosphere. Reflection High Energy Electron Diffraction (RHEED) and Scanning Electron Microscopy (SEM) technics were used for structural characterization and FPP-100 device for resistance measurements. Results show that by solid state reaction applied at different RTA processes WSi2 phase could be formed.Resistivities as low as 2-3 mΩ.cm are obtained for 800 -1000 °C.

1980 ◽  
Vol 1 ◽  
Author(s):  
J. T. Schott ◽  
J. J. Comer

ABSTRACTVarious characterization techniques are applied to pulsed and cw laser-annealed polysilicon layers deposited on oxide layers. The results are used to compare these techniques as to the type and completeness of information provided, as well as sample preparation requirements and general ease or difficulty of measurement. The techniques employed include scanning electron microscopy (SEM), electron channeling micrographs and selected area channeling patterns (SACP), reflection (high energy) electron diffraction (RHEED), transmission electron microscopy (TEM) and selected area diffraction (SAD), x-ray diffraction, optical techniques and etching techniques.


1997 ◽  
Vol 482 ◽  
Author(s):  
P. D. Brown ◽  
D. M. Tricker ◽  
Y. Xin ◽  
T. S. Chengt ◽  
C. T. Foxont ◽  
...  

AbstractEpitaxial GaN grown by MBE has been characterised using the combined techniques of scanning electron microscopy / cathodoluminescence, reflection high energy electron diffraction (RHEED), and conventional transmission electron microscopy. Variations in spatial and spectral distributions of luminescence can arise due to embedded cubic inclusions within the hexagonal GaN matrix. The strong effect of doping on the crystallinity of the GaN deposit is illustrated, as determined by RHEED in a TEM.


NANO ◽  
2006 ◽  
Vol 01 (01) ◽  
pp. 73-76 ◽  
Author(s):  
JONGBOK PARK ◽  
SUNGHO JEONG ◽  
OK HWAN CHA ◽  
MUN SEOK JEONG ◽  
DO-KYEONG KO ◽  
...  

In this work, a simple method is reported for the synthesis of bundles of carbon nanostructures under room temperature and atmospheric pressure. A pulsed Nd:YAG laser (355 nm, 10 Hz) is focused into the mixture of ferrocene and xylene solutions to produce the nanostructures in which ferrocene plays the role of a catalyst while xylene is the carbon source for nanostructure growth. During the period of irradiation, the color of solution turns into dark brown from transparent orange. Upon the completion of irradiation, typically for an hour, a variety of bundles of carbon nanostructures are found in the solution. Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) are used to investigate the nanostructures.


Author(s):  
Douglas William Jones

Within the past 20 years, archaeobotanical research in the Eastern United States has documented an early agricultural complex before the dominance of the Mesoamerican domesticates (corn, beans, and squash) in late prehistoric and historic agricultural systems. This early agricultural complex consisted of domesticated plants such as Iva annua var.macrocarpa (Sumpweed or Marshelder), Hellanthus annuus (Sunflower) and Chenopodium berlandieri, (Goosefoot or Lasbsquarters), and heavily utilized plants such as Polygonum erectum (Erect Knotweed), Phalaris caroliniana (May grass), and Hordeum pusillum (Little Barley).Recent research involving the use of Scanning Electron Microscopy (SEM) specifically on Chenopodium has established diagnostic traits of wild and domesticated species seeds. This is important because carbonized or uncarbonized seeds are the most commonly recovered Chenopodium material from archaeological sites. The diagnostic seed traits assist archaeobotanists in identification of Chenopodium remains and provide a basis for evaluation of Chenopodium utilization in a culture's subsistence patterns. With the aid of SEM, an analysis of Chenopodium remains from three Late Prehistoric sites in Northwest Iowa (Blood Run [Oneota culture], Brewster [Mill Creek culture], and Chan-Ya-Ta [Mill Creek culture]) has been conducted to: 1) attempt seed identification to a species level, 2) evaluate the traits of the seeds for classification as either wild or domesticated, and 3) evaluate the role of Chenopodium utilization in both the Oneota and Mill Creek cultures.


Author(s):  
M. H. Kelley ◽  
J. Unguris ◽  
R. J. Celotta ◽  
D. T. Pierce

By measuring the spin polarization of secondary electrons generated in a scanning electron microscope, scanning electron microscopy with polarization analysis (SEMPA) can directly image the magnitude and direction of a material’s magnetization. Because the escape depth of the secondaries is only on the order of 1 nm, SEMPA is especially well-suited for investigating the magnetization of ultra-thin films and surfaces. We have exploited this feature of SEMPA to study the magnetic microstrcture and magnetic coupling in ferromagnetic multilayers where the layers may only be a few atomic layers thick. For example, we have measured the magnetic coupling in Fe/Cr/Fe(100) and Fe/Ag/Fe(100) trilayers and have found that the coupling oscillates between ferromagnetic and antiferromagnetic as a function of the Cr or Ag spacer thickness.The SEMPA apparatus has been described in detail elsewhere. The sample consisted of a magnetic sandwich structure with a wedge-shaped interlayer as shown in Fig. 1.


2011 ◽  
Vol 691 ◽  
pp. 32-36
Author(s):  
José G. Miranda-Hernández ◽  
Elizabeth Refugio-García ◽  
Eduardo Térres-Rojas ◽  
Enrique Rocha-Rangel

The effect of different titanium additions (0.5, 1, 2, 3 and 10 vol. %), milling intensity (4 and 8 h) and sintered temperature (1500 and 1600 °C) on microstructure and fracture toughness of Al2O3-based composites was analyzed in this study. After high energy milling of a titanium and Al2O3mixtures, powder mixture presents fine distribution and good homogenization between ceramic and metal. After milling powders during 8 h they were obtained very fine particles with 200 nm average sizes. Microstructures of the sintered bodies were analyzed with a scanning electron microscopy, where it was observed that the microstructure presents the formation of a small and fine metallic net inside the ceramic matrix. From fracture toughness measurements realized by the fracture indentation method, it had that when titanium content in the composite increases, fracture toughness is enhanced until 83% with respect to the fracture toughness of pure Al2O3. This behavior is due to the formation of metallic bridges by titanium in the Al2O3matrix.


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