Light-Scattering Measurements of CVD Silicon Carbide

1989 ◽  
Vol 168 ◽  
Author(s):  
B. W. Sheldon ◽  
T. M. Besmann
Keyword(s):  
Silicon Carbide ◽  
Light Scattering ◽  
Scattered Light ◽  
Chemical Vapor ◽  
Helium Neon Laser ◽  
Simple Basis ◽  
Vector Theory ◽  
Complete Vector ◽  
Surface Morphologies ◽  
Helium Neon

AbstractSurface morphologies created by the chemical vapor deposition (CVD) of silicon carbide were examined with light scattering. Silicon carbide was deposited from methyltrichlorosilane under various conditions to create different surfaces. A helium neon laser was used, and the scattered light was measured over a range of scattering angles. These measurements are compared with scanning electron microscopy (SEM) observations and profilometer measurements of the same surfaces. In theory the scattered light contains all of the information needed to provide a statistical description of a given surface; however, a complete vector theory for the scattering phenomena is too complex to provide any simple basis for experimental analysis. The application and limits of existing descriptions of scattering from a rough surface are discussed.

In-Situ Light-Scattering Measurements During the CVD of Polycrystalline Silicon Carbide

1991 ◽  
Vol 250 ◽  
Author(s):  
Brian W. Sheldon ◽  
Philip A. Reichle ◽  
Theodore M. Besmann
Keyword(s):  
Silicon Carbide ◽  
Light Scattering ◽  
Polycrystalline Silicon ◽  
Chemical Vapor ◽  
Nucleation And Growth ◽  
Scattering Spectrum ◽  
Angular Scattering ◽  
Polycrystalline Silicon Carbide ◽  
Scattering Spectra

AbstractLight-scattering was used to monitor the chemical vapor deposition of silicon carbide from methyltrichlorosilane. The nucleation and growth of the SiC features caused changes in the surface topography that altered the angular scattering spectrum that was generated with a He-Ne laser. These scattering spectra were then analyzed to obtain information about the nucleation and growth processes that are occurring.

The Nucleation and Growth of Polycrystalline Silicon Carbide

1990 ◽  
Vol 202 ◽  
Author(s):  
Brian W. Sheldon ◽  
Theodore M. Besmann
Keyword(s):  
Silicon Carbide ◽  
Image Analysis ◽  
Light Scattering ◽  
Growth Rates ◽  
Growth Models ◽  
Scattered Light ◽  
Angular Spectrum ◽  
Nucleation And Growth ◽  
Reduced Pressure ◽  
Scattering Spectra

ABSTRACTSilicon carbide was deposited from methyltrichlorosilane onto polished polycrystalline SiC substrates at reduced pressure, and the resultant surface morphology was characterized by analyzing the angular spectrum of scattered light which was generated with a He-Ne laser. Light-scattering analyses incorporating specific nucleation and growth models were developed. With these methods, it was possible to analyze the angular scattering spectra and directly measure the nucleation and growth rates. These results were verified by using image analysis to quantify the number and size distribution of surface features that were observed with scanning electron microscopy. The nucleation and growth rates that were obtained by fitting the models to the image-analysis results were in good agreement with the rates obtained from the light-scattering.

TEM of grain growth and phase transformations during creep of SCS-6 silicon carbide fibers

1995 ◽  
Vol 53 ◽  
pp. 350-351
Author(s):  
L. A. Giannuzzi ◽  
C. A. Lewinsohn ◽  
C. E. Bakis ◽  
R. E. Tressler
Keyword(s):  
Silicon Carbide ◽  
Creep Rate ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Primary Creep ◽  
Excess Carbon ◽  
Silicon Carbide Fibers ◽  
Sic Fiber ◽  
Carbon Core ◽  
Grain Width

The SCS-6 SiC fiber is a 142 μm diameter fiber consisting of four distinct regions of βSiC. These SiC regions vary in excess carbon content ranging from 10 a/o down to 5 a/o in the SiC1 through SiC3 region. The SiC4 region is stoichiometric. The SiC sub-grains in all regions grow radially outward from the carbon core of the fiber during the chemical vapor deposition processing of these fibers. In general, the sub-grain width changes from 50nm to 250nm while maintaining an aspect ratio of ~10:1 from the SiC1 through the SiC4 regions. In addition, the SiC shows a <110> texture, i.e., the {111} planes lie ±15° along the fiber axes. Previous has shown that the SCS-6 fiber (as well as the SCS-9 and the developmental SCS-50 μm fiber) undergoes primary creep (i.e., the creep rate constantly decreases as a function of time) throughout the lifetime of the creep test.

STABILITY OF SYMMETRIC BILATERAL DC DISCHARGE IN A RING HELIUM-NEON LASER

2019 ◽  
Vol 69 ◽  
pp. 193-201
Author(s):  
M.V. Chirkin ◽  
◽  
S.V. Ustinov ◽  
V.Yu. Mishin ◽  
◽  
...  
Keyword(s):  
Neon Laser ◽  
Dc Discharge ◽  
Helium Neon Laser ◽  
Helium Neon

A Time-Resolved Low-Angle Light Scattering Apparatus. Application to Phase Separation Problems in Polymer Systems

2001 ◽  
Vol 66 (6) ◽  
pp. 973-982 ◽  
Author(s):  
Čestmír Koňák ◽  
Jaroslav Holoubek ◽  
Petr Štěpánek
Keyword(s):  
Phase Separation ◽  
Light Scattering ◽  
Signal To Noise Ratio ◽  
Scattered Light ◽  
Ccd Camera ◽  
Time Resolved ◽  
Polymer Systems ◽  
Software Analysis ◽  
Phase Separation Kinetics ◽  
Small Angle Light Scattering

A time-resolved small-angle light scattering apparatus equipped with azimuthal integration by means of a conical lens or software analysis of scattering patterns detected with a CCD camera was developed. Averaging allows a significant reduction of the signal-to-noise ratio of scattered light and makes this technique suitable for investigation of phase separation kinetics. Examples of applications to time evolution of phase separation in concentrated statistical copolymer solutions and dissolution of phase-separated domains in polymer blends are given.

scholarly journals Light-Scattering Simulations from Spherical Bimetallic Core–Shell Nanoparticles

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 359
Author(s):  
Francesco Ruffino
Keyword(s):  
Optical Properties ◽  
Light Scattering ◽  
Bimetallic Nanoparticles ◽  
Dominant Role ◽  
Scattered Light ◽  
Specific Interaction ◽  
Surface Enhanced Raman Spectroscopy ◽  
Localized Surface Plasmon ◽  
Core Shell ◽  
The Core

Bimetallic nanoparticles show novel electronic, optical, catalytic or photocatalytic properties different from those of monometallic nanoparticles and arising from the combination of the properties related to the presence of two individual metals but also from the synergy between the two metals. In this regard, bimetallic nanoparticles find applications in several technological areas ranging from energy production and storage to sensing. Often, these applications are based on optical properties of the bimetallic nanoparticles, for example, in plasmonic solar cells or in surface-enhanced Raman spectroscopy-based sensors. Hence, in these applications, the specific interaction between the bimetallic nanoparticles and the electromagnetic radiation plays the dominant role: properties as localized surface plasmon resonances and light-scattering efficiency are determined by the structure and shape of the bimetallic nanoparticles. In particular, for example, concerning core-shell bimetallic nanoparticles, the optical properties are strongly affected by the core/shell sizes ratio. On the basis of these considerations, in the present work, the Mie theory is used to analyze the light-scattering properties of bimetallic core–shell spherical nanoparticles (Au/Ag, AuPd, AuPt, CuAg, PdPt). By changing the core and shell sizes, calculations of the intensity of scattered light from these nanoparticles are reported in polar diagrams, and a comparison between the resulting scattering efficiencies is carried out so as to set a general framework useful to design light-scattering-based devices for desired applications.

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