scholarly journals Influence of Active Nitrogen Species on the Nitridation Rate of Sapphire

1998 ◽  
Vol 537 ◽  
Author(s):  
A.J. Ptak ◽  
K.S. Ziemer ◽  
M.R. Millecchia ◽  
C.D. Stinespring ◽  
T.H. Myers
Keyword(s):  
Molecular Nitrogen ◽  
Active Species ◽  
Operating Conditions ◽  
Rf Plasma ◽  
Atomic Nitrogen ◽  
Active Nitrogen ◽  
Plasma Sources ◽  
Electrostatic Deflector ◽  
Low Energy Ions ◽  
Operating Regimes

AbstractThe operating regimes of two rf-plasma sources, an Oxford CARS-25 and an EPI Unibulb, have been extensively characterized. By changing the exit aperture configuration and using an electrostatic deflector, the Oxford source could produce either primarily atomic nitrogen, atomic nitrogen mixed with low energy ions, or a large flux of higher energy ions (>65eV) as the active species in a background of neutral molecular nitrogen. The EPI source produced a significant flux of metastable molecular nitrogen as the active species with a smaller atomic nitrogen component. Nitridation of sapphire using each source under the various operating conditions indicate that the reactivity was different for each type of active nitrogen. Boron contamination originating from the pyrolytic boron nitride plasma cell liner was observed.

scholarly journals Influence of Active Nitrogen Species on the Nitridation Rate of Sapphire

1999 ◽  
Vol 4 (S1) ◽  
pp. 161-166 ◽  
Author(s):  
A.J. Ptak ◽  
K.S. Ziemer ◽  
M.R. Millecchia ◽  
C.D. Stinespring ◽  
T.H. Myers
Keyword(s):  
Molecular Nitrogen ◽  
Active Species ◽  
Operating Conditions ◽  
Rf Plasma ◽  
Atomic Nitrogen ◽  
Active Nitrogen ◽  
Plasma Sources ◽  
Electrostatic Deflector ◽  
Low Energy Ions ◽  
Operating Regimes

The operating regimes of two rf-plasma sources, an Oxford CARS-25 and an EPI Unibulb, have been extensively characterized. By changing the exit aperture configuration and using an electrostatic deflector, the Oxford source could produce either primarily atomic nitrogen, atomic nitrogen mixed with low energy ions, or a large flux of higher energy ions (>65 eV) as the active species in a background of neutral molecular nitrogen. The EPI source produced a significant flux of metastable molecular nitrogen as the active species with a smaller atomic nitrogen component. Nitridation of sapphire using each source under the various operating conditions indicate that the reactivity was different for each type of active nitrogen. Boron contamination originating from the pyrolytic boron nitride plasma cell liner was observed.

MBE Growth of III-V Nitride Films and Quantum-Well Structures Using Multiple RF Plasma Sources

1996 ◽  
Vol 449 ◽  
Author(s):  
M. A. L. Johnson ◽  
Zhonghai Yu ◽  
C. Boney ◽  
W. H. Rowland ◽  
W. C. Hughes ◽  
...  
Keyword(s):  
Quantum Well ◽  
Deep Level ◽  
Buffer Layers ◽  
Rf Plasma ◽  
Multiple Sources ◽  
Single Quantum Well ◽  
Active Nitrogen ◽  
Mbe Growth ◽  
Plasma Sources ◽  
Quantum Well Structures

ABSTRACTMBE growth of III-V nitrides is being studied at NCSU using MOVPE grown GaN buffer layers on SiC as substrates. Rf plasma sources are being used for the generation of active nitrogen during MBE deposition. Through the use of multiple rf plasma sources, sufficient active nitrogen is generated in order to examine the properties of III-V nitride layers grown at higher substrate temperatures and growth rates. The resulting MBE-grown GaN films exhibit remarkably intense photoluminescence (PL) dominated by a sharp band-edge peak at 3.409 eV having a FWHM of 36 meV at 300K. No deep level emission is observed. AlGaN and InGaN films and quantum well structures have also been prepared using multiple sources. A modulated beam MBE approach is used in conjunction with the multiple rf plasma sources to grow InGaN. RHEED and TEM studies reveal flat 2D InGaN quantum well structures. Depending on the indium content, GaN/InGaN single-quantum-well structures exhibit electroluminescence at 300K peaked in the blue-violet to the green spectral region.

Influence of Nitrogen Species on InN Grown by PAMBE

2005 ◽  
Vol 892 ◽  
Author(s):  
P. A. Anderson ◽  
R. J. Kinsey ◽  
C. E. Kendrick ◽  
I. Farrel ◽  
D. Carder ◽  
...  
Keyword(s):  
Emission Spectroscopy ◽  
Molecular Nitrogen ◽  
Optical Emission ◽  
Lattice Relaxation ◽  
Plasma Source ◽  
High Energy ◽  
Active Species ◽  
Nitrogen Species ◽  
Active Nitrogen ◽  
Molecular Flux

AbstractActive nitrogen species produced by an Oxford Applied Research HD-25 plasma source have been monitored by optical emission spectroscopy and quadrapole mass spectroscopy. Both techniques confirmed that at higher RF powers and lower flow rates the efficiency of atomic nitrogen production increased; emission spectroscopy confirmed that this was at the expense of active molecular nitrogen (N2*). InN films grown on (0001) sapphire/GaN with higher relative molecular content were found to have lower carrier concentrations than the corresponding films grown with higher atomic content. However, electrical properties of films grown on (111) YSZ showed insensitivity to the active nitrogen content. Etching experiments revealed that films grown on sapphire/GaN were nitrogen-polar, while films grown on YSZ were In-polar, suggesting that film polarity can greatly influence the effect active species have on growth. Lattice relaxation, as measured by reflection high-energy electron diffraction, revealed that the N-polar films grown under high relative molecular flux relaxed fully after ∼60 nm of growth, while the corresponding In-polar film relaxed fully within the first several nm of growth.

scholarly journals Nanofabrication using home-made RF plasma coupled chemical vapour deposition system

2014 ◽  
Vol 32 ◽  
pp. 1460342
Author(s):  
Si Ci Ong ◽  
Usman Ilyas ◽  
Rajdeep Singh Rawat
Keyword(s):  
Chemical Vapour ◽  
Chemical Vapor ◽  
Wide Band ◽  
Zno Nanowires ◽  
Operating Conditions ◽  
Rf Plasma ◽  
Zno Nanostructures ◽  
Energetic Ions ◽  
Cvd Method ◽  
Etching Effect

Zinc oxide, ZnO , a popular semiconductor material with a wide band gap (3.37 eV) and high binding energy of the exciton (60 meV), has numerous applications such as in optoelectronics, chemical/biological sensors, and drug delivery. This project aims to (i) optimize the operating conditions for growth of ZnO nanostructures using the chemical vapor deposition (CVD) method, and (ii) investigate the effects of coupling radiofrequency (RF) plasma to the CVD method on the quality of ZnO nanostructures. First, ZnO nanowires were synthesized using a home-made reaction setup on gold-coated and non-coated Si (100) substrates at 950 °C. XRD, SEM, EDX, and PL measurements were used for characterizations and it was found that a deposition duration of 10 minutes produced the most well-defined ZnO nanowires. SEM analysis revealed that the nanowires had diameters ranging from 30-100 mm and lengths ranging from 1-4 µm. In addition, PL analysis showed strong UV emission at 380 nm, making it suitable for UV lasing. Next, RF plasma was introduced for 30 minutes. Both remote and in situ RF plasma produced less satisfactory ZnO nanostructures with poorer crystalline structure, surface morphology, and optical properties due to etching effect of energetic ions produced from plasma. However, a reduction in plasma discharge duration to 10 minutes produced thicker and shorter ZnO nanostructures. Based on experimentation conducted, it is insufficient to conclude that RF plasma cannot aid in producing well-defined ZnO nanostructures. It can be deduced that the etching effect of energetic ions outweighed the increased oxygen radical production in RF plasma nanofabrication.

THE REACTION OF ACTIVE NITROGEN WITH PROPYLENE

1952 ◽  
Vol 30 (12) ◽  
pp. 915-921 ◽  
Author(s):  
G. S. Trick ◽  
C. A. Winkler
Keyword(s):  
Double Bond ◽  
Nitrogen Atom ◽  
Hydrogen Cyanide ◽  
Atomic Hydrogen ◽  
Atomic Nitrogen ◽  
Active Nitrogen

The reaction of nitrogen atoms with propylene has been found to produce hydrogen cyanide and ethylene as the main products, together with smaller amounts of ethane and propane and traces of acetylene and of a C4 fraction. With excess propylene, the nitrogen atoms were completely consumed and for the reaction at 242 °C., 0.77 mole of ethylene was produced for each mole of excess propylene added. For reactions at lower temperatures, less ethylene was produced. The proposed mechanism involves formation of a complex between the nitrogen atom and the double bond of propylene, followed by decomposition to ethylene, hydrogen cyanide, and atomic hydrogen. The ethylene would then react with atomic nitrogen in a similar manner.

High temperature electrons exhausted from rf plasma sources along a magnetic nozzle

2017 ◽  
Vol 24 (8) ◽  
pp. 084503 ◽  
Author(s):  
Kazunori Takahashi ◽  
Hikaru Akahoshi ◽  
Christine Charles ◽  
Rod W. Boswell ◽  
Akira Ando
Keyword(s):  
High Temperature ◽  
Rf Plasma ◽  
Plasma Sources ◽  
Magnetic Nozzle

Low-power inductive RF plasma sources for technological applications

2004 ◽  
Vol 30 (8) ◽  
pp. 687-697 ◽  
Author(s):  
K. V. Vavilin ◽  
A. A. Rukhadze ◽  
M. Kh. Ri ◽  
V. Yu. Plaksin
Keyword(s):  
Low Power ◽  
Rf Plasma ◽  
Plasma Sources

Plasma Sources for a High Flux of Active Species

2021 ◽  
pp. 202-231
Author(s):  
Alinka Vesel ◽  
Miran Mozetic ◽  
A. Ricard
Keyword(s):  
Active Species ◽  
High Flux ◽  
Plasma Sources

Destructive Accumulation of Nitrogen in 30 Cr 20 Ni Cast Furnace Tubes in Hydrocarbon Cracking Service at 1100 C

CORROSION ◽  
1967 ◽  
Vol 23 (9) ◽  
pp. 276-287 ◽  
Author(s):  
J. R. SCHLEY ◽  
F. W. BENNETT
Keyword(s):  
Laboratory Experiments ◽  
Tube Wall ◽  
Structural Characteristics ◽  
Molecular Nitrogen ◽  
Operating Conditions ◽  
High Nitrogen Content ◽  
High Nitrogen ◽  
Micro Structure ◽  
Nitrogen Gas ◽  
Centrifugally Cast

Abstract Centrifugally cast furnace tubes of 30 Cr, 20 Ni, balance iron, exhibited certain unusual structural characteristics after failure in service at 1100 C. A common feature of these tubes is a relatively high nitrogen content. In one instance, weakening and rupture of the tube wall under normal operating conditions was associated with a nitrogen-rich phase in the alloy micro-structure. Other cases were noted in which porosity and actual blisters developed within the walls of high-nitrogen tubes under conditions of severe carburization and overheating. Similar phenomena were produced in laboratory experiments and a mechanism involving the evolution of molecular nitrogen gas within the alloy is postulated.

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