A Model of Silicon Carbide Chemical Vapor Deposition

Allendorf, Mark D.; Kee, Robert J.

doi:10.1149/1.2085688

Cited by 202 publications

(152 citation statements)

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“…Process 2a is 49.8 kcal!mol endothermic with a barrier of 71.9 kcal/ 4, respectively. The kinetic energy release distribution (KERD)2 2 for dehydrogenation CH 3 SiH 2 + -SiCH 3 + + H 2 CH 3 SiClH+ -SiCH 3 + + HCl (3) (4) of metastable CH3SiHz + suggests two distinct mechanisms with substantially different kinetic energy releases. 20 This was interpreted by invoking 1,1-dehydrogenation from the silicon atom (large kinetic energy release) and 1,1-dehydrogenation from the carbon atom (narrow kinetic energy release).…”

Section: Introductionmentioning

confidence: 99%

Ab Initio Molecular Orbital Investigation of the Unimolecular Decomposition of CH3SiH2+

Gordon¹,

Pederson²,

Bakhtiar³

et al. 1995

J. Phys. Chem.

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The potential energy surface for the decomposition of CH3SiH2+ was studied by ub initio electronic structure theory. At the MP2/6-31G(d,p) level of theory, CH3SiH2+ is the only minimum energy structure on the SiCH5+ potential energy surface. Lower levels of theory reported that +CH2SiH3 was also a local minimum, about 40 kcal/mol higher in energy with only a small (ca. 1-2 kcdmol) banier for conversion back to CH3SiH2+. However, at higher levels of theory, the C, structure of +CHzSiH3 has an imaginary frequency, indicating that it is a saddle point rather than a local minimum on the potential energy surface. The 0 K reaction enthalpies for 1,1 -dehydrogenation from silicon, 1,2-dehydrogenation, 1,l -dehydrogenation from carbon, and demethanation were calculated to be 30.2,69.1, 107.3, and 45.3 kcdmol, respectively. Activation energies (0 K) were calculated at the MP4/6-311++G(2df,2pd) level of theory with the classical barriers subsequently adjusted for zero-point vibrational energies. The 0 K activation energies for 1,l-dehydrogenation from silicon, l,Zdehydrogenation, and demethanation are predicted to be 66.6, 72.7, and 73.0 kcavmol, respectively. All attempts to locate a transition state for the insertion of the carbene-like species, CHSiHZ+, into Hz (reverse of the 1,l-dehydrogenation from carbon) were unsuccessful. This is not surprising since analogous carbene insertions are known to occur without a barrier. Thus, we conclude that this 1,l-H2 elimination from carbon proceeds monotonically uphill. The closed-shell structures for the products of the above reactions (CH3Si+, CH2SiH+, and CHSiH2+) were calculated at the MP2/6-31G(p,d) level of theory. Finally, triplet products were also examined. Disciplines Chemistry CommentsReprinted ( June 28, 1994; In Final Form: October 19, 1994° The potential energy surface for the decomposition of CH3SiHz + was studied by ab initio electronic structure theory. At the MP2/6-31G(d,p) level of theory, CH 3 SiHz+ is the only minimum energy structure on the SiCHs + potential energy surface. Lower levels of theory reported that +cHzSiH 3 was also a local minimum, about 40 kcaVmol higher in energy with only a small (ca. 1-2 kcaVmol) barrier for conversion back to CH3SiHz+. However, at higher levels of theory, the c. structure of +cHzSiH3 has an imaginary frequency, indicating that it is a saddle point rather than a local minimum on the potential energy surface. The 0 K reaction enthalpies for 1, !-dehydrogenation from silicon, 1 ,2-dehydrogenation, 1, !-dehydrogenation from carbon, and demethanation were calculated to be 30.2, 69.1, 107.3, and 45.3 kcaVmol, respectively. Activation energies (0 K) were calculated at the MP4/6-311 ++G(2df,2pd) level of theory with the classical barriers subsequently adjusted for zero-point vibrational energies. The 0 K activation energies for !,!-dehydrogenation from silicon, 1,2-dehydrogenation, and demethanation are predicted to be 66.6, 72.7, and 73.0 kcaVmol, respectively. All attempts to locate a transition state for the insert...

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Section: Introductionmentioning

confidence: 99%

Ab Initio Molecular Orbital Investigation of the Unimolecular Decomposition of CH3SiH2+

Gordon¹,

Pederson²,

Bakhtiar³

et al. 1995

J. Phys. Chem.

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“…This led us to study the gas-phase kinetics of hydrocarbons presented in the literature. In this study, we selected two models from the literature, one from Allendorf and Kee 41 and the other from de Persis et al 133 , as well as a model compiled by one of the authors. The simulation conditions were kept the same for all three and no depositions were allowed.…”

Section: Chapter 4 Results and Summarymentioning

confidence: 99%

“…Usage of CFD ranges from designing of reactor geometry to process control. CFD studies of SiC CVD were reported in Ref 38,[41][42][43] .…”

Section: Present Status Of Sic-cvd Process Modelingmentioning

confidence: 99%

“…For SiC deposition, the gas phase part involves C-Si-H-halide containing species. The reactions involving C-H and Si-H species, both experimental and theoretical data, are available in the literature 38,41,[44][45][46][47] and recently Cl-related reactions [48][49][50][51] have also become available based on ab initio and density functional theory (DFT) calculations. The data have been used extensively in CFD modeling 36,[51][52][53] .…”

Section: Present Status Of Sic-cvd Process Modelingmentioning

confidence: 99%

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A Quantum Chemical Exploration of SiC Chemical Vapor Deposition

Sukkaew¹

2017

Linköping Studies in Science and Technology. Dissertations

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SiC is a wide bandgap semiconductor with many attractive properties. It has attracted particular attentions in the areas of power and sensor devices as well as biomedical and biosensor applications. This is owing to its properties such as large bandgap, high breakdown electric field, high thermal conductivities and chemically robustness. Typically, SiC homoepitaxial layers are grown using the chemical vapor deposition (CVD) technique. Experimental studies of SiC CVD have been limited to post-process measuring of the layer rather than in situ measurements. In most cases, the observations are presented in terms of input conditions rather than in terms of the unknown growth condition near the surface. This makes it difficult to really understand the underlying mechanism of what causes the features observed experimentally. With help of computational methods such as computational fluid dynamic (CFD) we can now explore various variables that are usually not possible to measure. CFD modeling of SiC CVD, however, requires inputs such as thermochemical properties and chemical reactions, which in many cases are not known. In this thesis, we use quantum chemical calculations to provide the missing details complementary to CFD modeling.We first determine the thermochemical properties of the halides and halohydrides of Si and C species, SiHnXm and CHnXm, for X being F, Cl and Br which were shown to be reliable compared to the available experimental and/or theoretical data. In the study of gas-phase kinetics, we combine ab initio methods and DFTs with conventional transition state theory to derive kinetic parameters for gas phase reactions related to Si-H-X species. Lastly, we study surface adsorptions related to SiC-CVD such as adsorptions of small C-H and Si-H-X species, and in the case of C-H adsorption, the study was extended to include subsequent surface reactions where stable surface products may be formed. iv SammanfattningSiC är ett halvledarmaterial med stort bandgap som har många attraktiva egenskaper. Det har fått särskilt mycket uppmärksamhet inom kraftkomponenter och sensorer, men också för tillämpningar inom biomedicin och biosensorer. Detta beror på materialets stora bandgap, förmågan att klara höga elektriska fält, goda värmeledningsförmåga och kemiska stabilitet. Epitaxiska skikt av SiC för kommersiella tillämpningar tillverkas med hjälp av kemisk ångdepo-sition (Chemical Vapor Deposition, CVD). Experimentella studier av SiC CVD begränsas till mätningar som görs i efterhand, snarare än under processens gång. För det mesta görs observationer med utgångspunkt från processens ingångsvärden istället för från de okända tillväxtförhållandena vid ytan. Detta gör det svårt att verkligen förstå de underliggande mekanismerna för de observerade experimentella resultaten. Med hjälp av beräkningsmetoder, såsom computational fluid dynamics (CFD) kan vi utforska olika variabler som vanligtvis inte går att mäta. Dock kräver CFD-modellering av SiC CVD ingångs-data i form av termokemiska egenskaper och kemiska reaktion...

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“…Our results indicate that, in the case of a chemically inert heating zone, the major growth species are Si and C 2 H 2 , resulting from the silane and hydrocarbon precursor decomposition, respectively. This corresponds to the SiC CVD case [17], provided formation of organo-silicon compounds can be neglected. When the incoming gas mixture is allowed to interact with the graphite environment of the growth chamber the major growth species are in turn SiC 2 , Si and Si 2 C, silicon acting in this case as a carbon transporting agent [18].…”

Section: Major Growth Speciesmentioning

confidence: 99%