Analysis of the Enhanced Growth Rate of Silicon-Oxide Layers in the Thin Regime by Incremental Growth

1992 ◽  
Vol 280 ◽  
Author(s):  
Sergio A. Ajuria ◽  
Prashant U. Kenkare ◽  
Anh Nghiem
Keyword(s):  
Growth Rate ◽  
Oxidation Kinetics ◽  
Silicon Oxide ◽  
Layer Formation ◽  
Silicon Oxidation ◽  
Initial Oxidation ◽  
Initial Layer ◽  
Oxidation Rates ◽  
Incremental Growth ◽  
Unique Method

ABSTRACTSilicon oxidation kinetics in the thin regime are studied by a unique method in which thermally grown as well as densified CVD-deposited oxides are incrementally reoxidized and measured. Strikingly higher oxidation rates are obtained through deposited oxides, as compared to thermal oxides, suggesting that oxidations are suppressed after an initial layer is grown rather than enhanced during initial layer formation. We show that these findings tend to support initial oxidation models based on stress.

Effects of Constituent Phases on Oxidation Kinetics of Al–Mg Alloys Containing a Trace of Ca

2021 ◽  
Vol 21 (3) ◽  
pp. 2067-2070
Author(s):  
Chul-Hong Bae ◽  
Seong-Ho Ha ◽  
Bong-Hwan Kim ◽  
Young-Ok Yoon ◽  
Hyun-Kyu Lim ◽  
...  
Keyword(s):  
Oxygen Partial Pressure ◽  
Intermetallic Compounds ◽  
Master Alloy ◽  
Oxidation Kinetics ◽  
Thermodynamic Calculation ◽  
Mg Alloys ◽  
Initial Oxidation ◽  
Oxidation Rates ◽  
Kinetics Of ◽  
Al Mg Alloys

In this study, the effects of constituent phases on the oxidation kinetics of an Al-7 mass%Mg alloy containing a trace of Ca were investigated. A Mg+Al2Ca master alloy was used to add Mg and Ca simultaneously. Scheil-Gulliver cooling by thermodynamic calculation showed that the addition of Ca led to the formation of Ca-based intermetallic compounds, such as Al4Ca and Laves C36, after solidification. Based on weight increase indicated by the oxidation test and surface analysis, it was found that the presence of Ca-based phases significantly improved the oxidation resistance and slowed down the oxidation rates. Based on the review of phase diagrams with oxygen partial pressure by thermodynamic calculation, it was thought that in the initial oxidation, MgO and MgAl2O4 were formed on the surfaces of the Al–Mg alloys, leading to further oxidation. The Ca-based intermetallic compounds formed Ca–Mg–Al based oxides, which possibly contributed to the formation of a relatively dense oxide layer.

Model Calculation of SiC Oxidation Rates in the Thin Oxide Regime

2008 ◽  
Vol 600-603 ◽  
pp. 663-666 ◽  
Author(s):  
Yasuto Hijikata ◽  
Takeshi Yamamoto ◽  
Hiroyuki Yaguchi ◽  
Sadafumi Yoshida
Keyword(s):  
Growth Rate ◽  
Model Calculation ◽  
Oxidation Mechanism ◽  
Oxide Thickness ◽  
Emission Model ◽  
Initial Oxidation ◽  
Oxidation Rates ◽  
Oxidation Stage ◽  
Thin Oxide

To explain the growth rate enhancement of SiC oxidation in the thin oxide regime, which was recently found from the real time monitoring experiments of the initial oxidation stage of SiC (000–1) C-face using an in-situ spectroscopic ellipsometer, we tried to apply the interfacial Si emission model, which has been originally proposed for Si oxidation, and found that the Si emission model successfully reproduced the SiC oxidation rates at the whole range of oxide thickness and at oxidation temperatures measured. By comparing with the simulations for Si oxidation, we have discussed the oxidation mechanism of SiC.

Structire, Properties, and Process Characteristics of Low-K Materials Prepared by PECVD

1999 ◽  
Vol 565 ◽  
Author(s):  
Y. Shimogaki ◽  
S. W. Lim ◽  
E. G. Loh ◽  
Y. Nakano ◽  
K. Tada ◽  
...  
Keyword(s):  
Growth Rate ◽  
Dielectric Constant ◽  
Gas Flow ◽  
Structural Changes ◽  
Silicon Oxide ◽  
Reactive Species ◽  
Low Dielectric Constant ◽  
Low Dielectric ◽  
Step Coverage ◽  
Low K

AbstractLow dielectric constant F-doped silicon oxide films (SiO:F) can be prepared by adding fluorine source, like as CF4 to the conventional PECVD processes. We could obtain SiO:F films with dielectric constant as low as 2.6 from the reaction mixture of SiH4/N2 O/CF4. The structural changes of the oxides were sensitively detected by Raman spectroscopy. The three-fold ring and network structure of the silicon oxides were selectively decreased by adding fluorine into the film. These structural changes contribute to the decrease ionic polarization of the film, but it was not the major factor for the low dielectric constant. The addition of fluorine was very effective to eliminate the Si-OH in the film and the disappearance of the Si-OH was the key factor to obtain low dielectric constant. A kinetic analysis of the process was also performed to investigate the reaction mechanism. We focused on the effect of gas flow rate, i.e. the residence time of the precursors in the reactor, on growth rate and step coverage of SiO:F films. It revealed that there exists two species to form SiO:F films. One is the reactive species which contributes to increase the growth rate and the other one is the less reactive species which contributes to have uniform step coverage. The same approach was made on the PECVD process to produce low-k C:F films from C2F4, and we found ionic species is the main precursor to form C:F films.

scholarly journals Effect of side-chain length in lignin model compound on MnO2 oxidation: comparison of oxidations between C6-C2- and C6-C1-type compounds

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Shirong Sun ◽  
Tomoya Yokoyama
Keyword(s):  
Isotope Effects ◽  
Aromatic Nucleus ◽  
Side Chain ◽  
Direct Oxidation ◽  
Initial Oxidation ◽  
Methyl Group ◽  
Lignin Model Compound ◽  
Oxidation Rates ◽  
Kinetic Isotope ◽  
Lignin Model

AbstractMonomeric C6-C2-type lignin model compounds with a p-hydroxyphenyl (H), guaiacyl (G), syringyl (S), or p-ethylphenyl (E) nucleus (1-phenylethanol derivatives) were individually oxidized by MnO2 at a pH of 1.5 and room temperature. The results were compared with those of the corresponding C6-C1-type benzyl alcohol derivatives obtained in our recent report to examine the effect of the presence of the β-methyl group on the oxidation. The presence decelerated the oxidation regardless of the type of aromatic nucleus, although it did not change the order of the oxidation rates: G > S >> H > E. This deceleration results from the steric factor of the β-methyl group in the C6-C2-type compounds. The MnO2 oxidations of the corresponding C6-C2-type compounds deuterated at their α-(benzyl)positions showed that the magnitudes of the kinetic isotope effects are smaller than those observed in the oxidations of the corresponding C6-C1-type compounds, regardless of the type of aromatic nucleus. These smaller magnitudes suggest that the presence of the β-methyl group shifts the initial oxidation mode of MnO2 from direct oxidation of the benzyl position to one-electron oxidation of the aromatic nucleus. Only the S-type compounds afforded products via degradation of the aromatic nuclei.

scholarly journals Characteristics and Kinetics of Rosin Pentaerythritol Ester via Oxidation Process under Ultraviolet Irradiation

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2816 ◽  
Author(s):  
Yuanlin Li ◽  
Xiongmin Liu ◽  
Qiang Zhang ◽  
Bo Wang ◽  
Chang Yu ◽  
...  
Keyword(s):  
Light Intensity ◽  
Oxidation Kinetics ◽  
Pseudo First Order Reaction ◽  
Initial Oxidation ◽  
Photo Oxidation ◽  
Average Value ◽  
Pentaerythritol Ester ◽  
Fundamental Information ◽  
The Stability ◽  
Kinetics Of

A self-designed reaction device was used as a promising equipment to investigate the oxidation characteristics and kinetics of rosin pentaerythritol ester (RPE) under UV irradiation. Photo-oxidation kinetics and the initial quantum yield (Φ) of RPE were calculated. The initial oxidation product of the photo-oxidation reaction—peroxide was analyzed by iodimetry. The peroxide concentration is related to the light intensity (I) and the temperature (T), and the increasing T and I would destabilize the RPE by accelerating peroxide forming. Photo-oxidation of RPE follows the pseudo first-order reaction kinetics. The relationship between activation energy and logarithm of light intensity (ln I) is linear, and it is expressed as Ea = −4.937ln I + 45.565. Φ was calculated by the photo-oxidation kinetics, and the average value of Φ was 7.19% in the light intensity range of 200–800 μW cm−2. This research can provide fundamental information for application of RPE, and help obtain a better understanding of the stability of rosin esters.

scholarly journals Phytoremediation of Special Metals in Emerging Industries

2018 ◽  
Vol 1 (3) ◽  
Author(s):  
T Y TEH ◽  
Min-Hao Wu ◽  
Kf Chen ◽  
Yp Peng
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Growth Rate ◽  
Environmental Factors ◽  
Contaminated Soil ◽  
Morphological Analysis ◽  
Energy Crop ◽  
Emerging Industries ◽  
Incremental Growth ◽  
Conventional Methods

This project is carried out to assess the remediation effect on soil contaminated by molybdenum (Mo), one of heavy metals, through the use of an energy crop, sunflowers. This project explores the integration of phytohormones and chelates in the phytoremediation of soils contaminated by heavy metals, and further assesses the operational measures of remedying heavy-metal contaminated soil with sunflowers, in addition to the related environmental factors. Then the project explores phytohormones and heavy metals on the growth scenario explants (explants morphological analysis) through the experiment. The results indicate that GA3 can increase the growth rate of the plants. The average incremental growth of the heavy-metal-added-only group is 21.0 cm; of the GA3-added group it is 21.9 cm; of the EDDS-added group, it is 20.3 cm; of the GA3+ EDDS-added group, it is 21.7 cm. Compared with the conventional methods of phytoremediation, these integrated measures can actually spur the growth of plants. 

Oxidation Characteristics of Vapor-Plated Tungsten

CORROSION ◽  
1966 ◽  
Vol 22 (10) ◽  
pp. 291-293 ◽  
Author(s):  
VERNON A. NIEBERLEIN
Keyword(s):  
Powder Metallurgy ◽  
Vapor Deposition ◽  
Oxidation Kinetics ◽  
Activation Energies ◽  
Humid Air ◽  
Dry Air ◽  
Oxidation Rates ◽  
Complex Shapes ◽  
Oxidation Characteristics

Abstract Vapor-deposition is being used increasingly for fabricating complex shapes from tungsten. In contrast to conventional tungsten whose oxidation kinetics have been well explored, vapor-deposited material has never been investigated systematically with regard to oxidation. Oxidation rates were run at 600–1000 C (1112–1832 F) in air using a recording balance. Activation energies were calculated and oxidation rates were compared to those of sheet tungsten prepared using powder metallurgy techniques. Humid air and dry air were compared as corroding media.

Oxidation of PECVD SiC Deposited from Trimethylsilane

1998 ◽  
Vol 555 ◽  
Author(s):  
Peter A. DiFonzo ◽  
Mona Massuda ◽  
James T. Kelliher
Keyword(s):  
Thin Films ◽  
Silicon Carbide ◽  
Oxidation Kinetics ◽  
Stoichiometric Composition ◽  
Chemical Vapor ◽  
Oxidation Rates ◽  
Chemical Vapor Deposited ◽  
Kinetics Of ◽  
Sic Films ◽  
Deposition Conditions

AbstractThe stoichiometric composition and oxidation rates ( wet or dry ) of plasma enhanced chemical vapor deposited (PECVD) silicon carbide (SiC) films are effected by the deposition conditions of trimethylsilane (3MS) and carrier gas. We report the oxidation kinetics of SiC thin films deposited in a modified commercial PECVD reactor. A standard horizontal atmospheric furnace in the temperature range of 925–1100°C was used in the oxidation. Oxidized films were measured optically by commercially available interferometer and ellipsometer tools in addition to mechanically using a commercially available profilometer. Activation energies of the parabolic rates were in the range of 20.93 to 335.26 kJ/mol.

Growth Rate and Characterization of Silicon Oxide Films Grown in  N 2 O  Atmosphere in a Rapid Thermal Processor

1994 ◽  
Vol 141 (1) ◽  
pp. 259-263 ◽  
Author(s):  
P. Lange ◽  
H. Bernt ◽  
E. Hartmannsgruber ◽  
F. Naumann
Keyword(s):  
Growth Rate ◽  
Silicon Oxide ◽  
Oxide Films
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