Characterization Of Boron Films Prepared By Chemical Vapor Deposition And Their Application In X-Ray Imaging

1993 ◽  
Vol 306 ◽  
Author(s):  
Fang Yuan ◽  
David D. Allred
Keyword(s):  
Refractive Index ◽  
Chemical Vapor Deposition ◽  
Hydrogen Content ◽  
Vapor Deposition ◽  
Energy Gap ◽  
Complex Refractive Index ◽  
Chemical Vapor ◽  
Amorphous Semiconductor ◽  
X Ray ◽  
X Ray Imaging

AbstractBoron, a low Z element, is useful for x-ray optics since it has a low atomic absorption coefficient. Boron films prepared by chemical vapor deposition were characterized optically, electronically and mechanically. Auger, infrared and hydrogen effusion analyses showed that the films are amorphous hydrogenated boron. The hydrogen content ranges from 8–71%. The measurements of the complex refractive index and the resistance vs. temperature determined that they are a typical amorphous semiconductor with the energy gap ranging from 1.09 to 1.36 eV, decreasing with increasing hydrogen content and with the Fermi energy level pinned about midgap. The real refractive index at 490 nm increases from 3.25–3.59 with increasing hydrogen content. The Young's modulus and hardness were found to be 3.05 × 1013 dyne/cm2 and around 2500 Vickers, respectively. The chemical tests suggested that boron films are stable in nonoxidizing bases and concentrated acids. Some oxidizing bases such as basic ferricyanide and permanganate solutions are good etchants for CVD boron films. Boron coated beryllium x-ray windows which have enhanced resistance to degradation are now commercially available, and self-supporting boron windows are potential future products for x-ray imaging.

Characterization ofa‐SiC:H films produced in a standard plasma enhanced chemical vapor deposition system for x‐ray mask application

1992 ◽  
Vol 72 (7) ◽  
pp. 3110-3115 ◽  
Author(s):  
A. Jean ◽  
M. Chaker ◽  
Y. Diawara ◽  
P. K. Leung ◽  
E. Gat ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
X Ray

A soft X-ray absorption study of nanodiamond films prepared by hot-filament chemical vapor deposition

2003 ◽  
Vol 372 (3-4) ◽  
pp. 320-324 ◽  
Author(s):  
Y.H Tang ◽  
X.T Zhou ◽  
Y.F Hu ◽  
C.S Lee ◽  
S.T Lee ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Absorption Study ◽  
X Ray ◽  
Hot Filament ◽  
X Ray Absorption

High Quality GaAs Mis Diodes With Very Low Surface State Density

1990 ◽  
Vol 209 ◽  
Author(s):  
Yoshihisa Fujisaki ◽  
Sumiko Sakai ◽  
Saburo Ataka ◽  
Kenji Shibata
Keyword(s):  
Chemical Vapor Deposition ◽  
Density Of States ◽  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
State Density ◽  
High Quality ◽  
Metal Insulator ◽  
X Ray ◽  
Mis Devices

ABSTRACTHigh quality GaAs/SiO2 MIS( Metal Insulator Semiconductor ) diodes were fabricated using (NH4)2S treatment and photo-assisted CVD( Chemical Vapor Deposition ). The density of states at the GaAs and SiO2 interface is the order of 1011 cm-2eV-1 throughout the forbidden energy range, which is smaller by the order of two than that of the MIS devices made by the conventional CVD process. The mechanism attributable to the interface improvement was investigated through XPS( X-ray Photoelectron Spectroscopy ) analyses.

Highly Tm Doped Silica Optical Preform by MCVD - Chelate Vapor Delivery (Soot-Dopant Stepwise Technique)

2018 ◽  
Vol 780 ◽  
pp. 57-61 ◽  
Author(s):  
K.A. Mat-Sharif ◽  
Nasr Y.M. Omar ◽  
M.I. Zulkifli ◽  
S.Z. Muhd-Yassin ◽  
Y.K. Sin ◽  
...  
Keyword(s):  
Refractive Index ◽  
Absorption Spectrum ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Absorption Peak ◽  
Strong Absorption ◽  
Silica Fiber ◽  
Index Variation ◽  
Strong Absorption Peak

This paper presents the progress in the fabrication of highly doped thulium silica fiber. As much as 5.3 wt. % Tm alongside 7.1 wt. % Al (co-dopant) were incorporated into silica preform. The preform was fabricated using the Modified Chemical Vapor Deposition (MCVD)-chelate vapor delivery with soot-dopant stepwise technique. The preform was analyzed for several key properties such as refractive index variation along deposition length, dopants distribution profiles and UV-Vis absorption. The results showed a homogeneous dopants distribution with 4% RSD in the longitudinal refractive index along a 40 cm preform length. The UV-Vis absorption spectrum exhibited a strong absorption peak at 790 nm attributed to Tm 3H4 energy manifold.

scholarly journals Epitaxial Growth of Magnesia Films on Single Crystalline Magnesia Substrates by Atmospheric-Pressure Chemical Vapor Deposition

2016 ◽  
Vol 5 (2) ◽  
pp. 56
Author(s):  
Keiji Komatsu ◽  
Pineda Marulanda David Alonso ◽  
Nozomi Kobayashi ◽  
Ikumi Toda ◽  
Shigeo Ohshio ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Single Crystal ◽  
Vapor Deposition ◽  
Atmospheric Pressure ◽  
Reciprocal Lattice ◽  
Chemical Vapor ◽  
X Ray ◽  
Pole Figures ◽  
Out Of Plane ◽  
Pressure Chemical

<p class="1Body">MgO films were epitaxially grown on single crystal MgO substrates by atmospheric-pressure chemical vapor deposition (CVD). Reciprocal lattice mappings and X-ray reflection pole figures were used to evaluate the crystal quality of the synthesized films and their epitaxial relation to their respective substrates. The X-ray diffraction profiles indicated that the substrates were oriented out-of-plane during MgO crystal growth. Subsequent pole figure measurements showed how all the MgO films retained the substrate in-plane orientations by expressing the same pole arrangements. The reciprocal lattice mappings indicated that the whisker film showed a relatively strong streak while the continuous film showed a weak one. Hence, highly crystalline epitaxial MgO thin films were synthesized on single crystal MgO substrates by atmospheric-pressure CVD.</p>

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