Silicon Nitride Coatings Formed using the Selective Area Laser Deposition (SALD) Technique

1998 ◽  
Vol 555 ◽  
Author(s):  
Lianchao Sun ◽  
Leon L. Shaw ◽  
Harris L. Marcus
Keyword(s):  
Activation Energy ◽  
Silicon Nitride ◽  
Gas Phase ◽  
Total Pressure ◽  
Volume Growth ◽  
Laser Deposition ◽  
Amorphous Phases ◽  
Selective Area ◽  
Heat Treated ◽  
Nitride Coatings

AbstractIn this paper, the Selective Area Laser Deposition (SALD) technique was used to deposit silicon nitride material from the gas phase. Tetramethylsilane (TMS) and ammonia were chosen as precursors for silicon and nitrogen respectively. Effects of processing temperatures and gas ratios of TMS to total pressure (PTMS + PNH3) on the relative amounts of silicon nitride and the growth kinetics were studied. Further, surface morphology and electrical properties of the deposits were also examined. It is found that the as-deposited materials are mainly composed of amorphous phases and the heat-treated samples (at 1500°C for 8hrs) consist of α-Si 3N4, α-SiC and β-SiC. The amount of αz-Si3N4 decreases with the increase of the TMS pressure. The volume growth rate of deposits also increases with the TMS pressure. The apparent activation energy for these processes is estimated as 1 OOkJ/mol.

Gas phase photochlorination of perfluorocyclohexene

1969 ◽  
Vol 47 (6) ◽  
pp. 1067-1069 ◽  
Author(s):  
J. J. Cosa ◽  
C. A. Vallana ◽  
E. H. Staricco
Keyword(s):  
Activation Energy ◽  
Quantum Yield ◽  
Gas Phase ◽  
Photochemical Reaction ◽  
Total Pressure ◽  
Square Root ◽  
Kcal Mole ◽  
Kinetics Of

The kinetics of the gas phase photochemical reaction between perfluorocyclohexene and chlorine was studied between 10 and 50 °C. The system was irradiated with light of 4360 Å. The rate of the photochlorination was independent of the perfluorocyclohexene pressure and of the total pressure. It was found to be proportional to the first power of the pressure of Cl2 and to the square root of the intensity of absorbed light. At 30 °C, the quantum yield was found to be 200 when the initial Cl2 pressure was 100 Torr, and intensity of light absorbed 9.89 × 10−9 einstein l−1s−1.An activation energy of 5.1 kcal/mole could be assigned to the reaction C6F10Cl + Cl2.

Solid Freeform Fabrication of Ceramics Using Selective Laser Sintering and Selective Area Laser Deposition

1991 ◽  
Vol 249 ◽  
Author(s):  
Uday Lakshminarayan ◽  
Guisheng Zong ◽  
W. Richards Thissell ◽  
Harris L. Marcus
Keyword(s):  
Gas Phase ◽  
Solid Freeform Fabrication ◽  
Laser System ◽  
Selective Laser Sintering ◽  
Three Dimensional ◽  
Laser Sintering ◽  
Laser Deposition ◽  
Powder Materials ◽  
Freeform Fabrication ◽  
Selective Area

ABSTRACTSolid Freeform Fabrication (SFF) is a new computer fabrication technique that does not require any part specific tooling. The starting material can be either solid, liquid or gaseous. The part can be made from metallic, ceramic, polymeric or a composite material. The concept is to use a solid modeling system to define the part of interest and to reduce the model to a set of toggle point data that totally define the geometry. In Selective Laser Sintering the sectioned component is then combined with a rastered laser system that impinges on the precursor powder materials in a layered reconstruction of the three dimensional CAD designed part. The part is then formed in this manner. This approach to producing the part involves a great deal of understanding of the laser materials interactions, the appropriate choice of materials specific to this processing and how the total process integrates. Application to ceramic powders will be described. An alternative approach to SFF is Selective Area Laser Deposition where the three dimensional part is made from the gas phase. The initial gas deposition studies involving deposition of carbon from hydrocarbons will be discussed. For both of the above SFF approaches the laser beam powder and gas phase interactions and the microstructure of the resulting three dimensional forms as a function of system parameters will be described.

Laser-Induced Selective Copper Deposition on Polyimides and Semiconductors

1992 ◽  
Vol 282 ◽  
Author(s):  
Seong-Don Hwang ◽  
S. S. Kher ◽  
J. T. Spencer ◽  
P. A. Dowben
Keyword(s):  
Gas Phase ◽  
Copper Chloride ◽  
Copper Deposition ◽  
Copper Films ◽  
Liquid Phase Deposition ◽  
Metal Thin Films ◽  
Selective Area ◽  
Phase Cluster ◽  
Photolytic Decomposition ◽  
Area Deposition

ABSTRACTIt has been demonstrated that copper can be selectively deposited on a variety of substrates including Teflon (polytetrafluroethylene or PTFE), Kapton (polyimide resin), silicon and gallium arsnide from solution by photo-assisted initiated deposition. A copper containing solution was prepared from a mixture of copper(I) chloride (Cu2Ci2) and decaborane (B10H14) in diethyl ether and/or THF (tetrahydrofuran). The copper films were fabricated by ultraviolet photolytic decomposition of copper chloride and polyhedral borane clusters. This liquid phase deposition has a gas-phase cluster analog that also results in copper deposition via pyrolysis. The approach of depositing metal thin films selectively by pholysis from solution is a novel and an underutilized approach to selective area deposition.

POLYMÉRISATION PAR LES RAYONS-X DU CHLORURE DE VINYLE À L'ÉTAT DE VAPEUR

1963 ◽  
Vol 41 (6) ◽  
pp. 1578-1587 ◽  
Author(s):  
Jan A. Herman ◽  
Pierre M. Hupin
Keyword(s):  
Activation Energy ◽  
Gas Phase ◽  
Average Molecular Weight ◽  
Negative Temperature ◽  
Solid Polymer ◽  
X Rays ◽  
Kcal Mole ◽  
Rate Of Polymerization ◽  
G Value ◽  
Termination Process

The polymerization of vinyl chloride in the gas phase by X rays gives a solid polymer of 1140 average molecular weight. The G value of monomer disappearance varies from 100 to 400 and depends on pressure and temperature. From the measure of the rate of polymerization it was possible to deduce the activation energy of the chain propagation steps: 2.5 kcal/mole, and that of the hindered termination process: 7.4 kcal/mole. The negative temperature co-efficient of the polymerization is explained by the importance of this hindered termination process.

Deposition of Polysilicon Films by Hot-Wire CVD at Low Temperatures for Photovoltaic Applications

1995 ◽  
Vol 377 ◽  
Author(s):  
J. Puigdollers ◽  
J. Bertomeu ◽  
J. Cifre ◽  
J. Andreu ◽  
J. C. Delgado
Keyword(s):  
Gas Phase ◽  
Chemical Vapor ◽  
Hot Wire ◽  
Amorphous Phases ◽  
Photovoltaic Applications ◽  
Polysilicon Films ◽  
Hydrogen Mixtures ◽  
Si Films ◽  
Substrate Temperatures ◽  
Very High

ABSTRACTPolysilicon (poly-Si) thin films have been obtained using hot-wire chemical vapor deposition (HWCVD) from silane-hydrogen mixtures. The films were prepared at low substrate temperatures (down to 200°C) and at very high deposition rates (up to 40 Å/s). They showed good crystalline properties and no amorphous phases were detected. The films can also be efficiently doped by adding diborane or phosphine to gas phase. In this paper, an overview of the properties of the poly-Si films, intrinsic and p and n-doped, deposited at our laboratory by HWCVD is presented and discussed. The properties of the material and the features of the deposition technique which are interesting for their application in photovoltaics are emphasized.

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