Surface Reaction Intermediates in Ge Chemical Vapor Deposition on Silicon

1993 ◽  
Vol 334 ◽  
Author(s):  
C. Michael Greenlief ◽  
Lori A. Keeling
Keyword(s):  
Gas Phase ◽  
Molecular Orbital ◽  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Surface Reaction ◽  
Chemical Vapor ◽  
Reaction Intermediates ◽  
Surface Species ◽  
Adsorbed Species ◽  
Orbital Energies

AbstractComputational programs are often used for estimating molecular orbital energies and geometries. The results of these calculations can also provide information needed for investigation of adsorption and decomposition mechanisms on surfaces. In this study, ab initio methods are used to calculate properties of gas phase diethylgermane and GeHx-substituted silanes (x=1−3). The silanes are used as models for surface Ge hydrides. The calculated gas phase molecular orbital energies are then compared with experimentally determined molecular orbital energies for the adsorbed species. The surface species are prepared by germane, digermane, ethylbromide, or diethylgermane adsorption on the Si(100)-(2×1) surface and the molecular orbital energies are measured by photoelectron spectroscopy.

Gas-Surface Reaction Studies Relevant to SiC Chemical Vapor Deposition

1988 ◽  
Vol 131 ◽  
Author(s):  
C. D. Stinespring ◽  
A. Freedman ◽  
J. C. Wormhoudt
Keyword(s):  
Solid State ◽  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Transport Process ◽  
Surface Reaction ◽  
Chemical Vapor ◽  
Nucleation Mechanism ◽  
Reaction Products ◽  
X Ray ◽  
Insight Into

ABSTRACTReactions of C2H4, C3H8, and CH4 on Si(111) and C2H4 on Si(100) have been investigated for surface temperatures in the range of 1062 K to 1495 K. These studies used x-ray photoelectron spectroscopy to identify the reaction products, characterize the solid state transport process, determine the nucleation mechanism and growth kinetics, and assess orienta-tion effects. The results are used to provide insight into the mechanisms of SiC CVD processes.

Gas-phase diffusion and surface reaction as limiting mechanisms in the aerosol-assisted chemical vapor deposition of TiO2 films from titanium diisopropoxide

2006 ◽  
Vol 21 (12) ◽  
pp. 3205-3209 ◽  
Author(s):  
A. Conde-Gallardo ◽  
M. Guerrero ◽  
R. Fragoso ◽  
N. Castillo
Keyword(s):  
Chemical Vapor Deposition ◽  
Gas Phase ◽  
Vapor Deposition ◽  
Surface Reaction ◽  
Crystalline Silicon ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
Thermal Reaction ◽  
Phase Diffusion ◽  
Wide Range

Titanium dioxide thin films were deposited on crystalline silicon (100) substrates by delivering a liquid aerosol of titanium-diisopropoxide. The evidence of a metalorganic chemical vapor deposition process observed in the crystalline and morphological features of the films is strongly supported by the behavior of the growth rate rg as a function of the deposition temperature. The rg line shape indicates that in a wide range of temperatures (∼180–400 °C), the film formation is limited by both gas-phase diffusion of some molecular species toward the substrate surface and the thermal reaction of those species on that surface. The activation energy EA that characterizes the surface reaction depends somewhat on the precursor concentration; a fitting procedure to an equation that takes into account both limiting mechanisms (gas-phase diffusion + surface reaction) yields EA ≃ 27.6 kJ/mol.

Gas-Phase Tautomerism in the Triazoles and Tetrazoles: A Study by Photoelectron Spectroscopy and ab Initio Molecular Orbital Calculations

1981 ◽  
Vol 36 (11) ◽  
pp. 1246-1252 ◽  
Author(s):  
Michael H. Palmer ◽  
Isobel Simpson ◽  
J. Ross Wheeler
Keyword(s):  
Ab Initio ◽  
Gas Phase ◽  
Molecular Orbital ◽  
Photoelectron Spectroscopy ◽  
Relative Stability ◽  
Photoelectron Spectra ◽  
Equilibrium Geometry ◽  
Molecular Orbital Calculations ◽  
Methyl Derivatives

The photoelectron spectra of the tautomeric 1,2,3,- and 1,2,4-triazole and 1,2,3,4-tetrazole systems have been compared with the corresponding N-methyl derivatives. The dominant tautomers in the gas phase have been identified as 2 H-1,2,3-triazole, 1 H-1,2,4-triazole and 2H-tetrazole.Full optimisation of the equilibrium geometry by ab initio molecular orbital methods leads to the same conclusions, for relative stability of the tautomers in each of the triazoles, but the calculations wrongly predict the tetrazole tautomerism.

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