Surface reactivity measurements for OH radicals during deposition of SiO2 from tetraethoxysilane/O2 plasmas

Bogart, K. H. A.; Cushing, J. P.; Fisher, Ellen R.

doi:10.1016/s0009-2614(97)00109-7

Cited by 24 publications

(39 citation statements)

References 20 publications

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“…To date, the IRIS method has been used to investigate five different radical species [14][15][16][17][18][19] in several plasma systems. 20,21 The OH radical, which is found in many chemical processes (i.e., combustion 22,23 and atmospheric reactions 24 ), has been extensively studied with this technique.…”

Section: Introductionmentioning

confidence: 99%

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Effects of Plasma Processing Parameters on the Surface Reactivity of OH(X²Π) in Tetraethoxysilane/O₂ Plasmas during Deposition of SiO₂

1997

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The OH(X 2 Π) radical in a 20:80 tetraethoxysilane (TEOS)/O 2 plasmas has been characterized during deposition of SiO 2 using the imaging of radicals interacting with surfaces (IRIS) method. The reactivity of OH at the surface of a growing SiO 2 film has been determined as a function of the applied radio-frequency (rf) plasma power (P) and the substrate temperature (T S ). The reactivity (R) of OH during deposition of SiO 2 on a 300 K Si substrate is 0.41 ( 0.04. R decreases as substrate temperature increases but is unaffected by increasing rf power. Translational and rotational temperatures (Θ T and Θ R , respectively) of the OH radical are also determined. For a 20:80 TEOS/O 2 plasma (P ) 85 W), Θ T ) 912 ( 20 K and Θ R ) 450 ( 20 K. Θ T is significantly higher than Θ R and increases with increasing rf power. Using isotopically labeled 18 O 2 as a precursor, the source of the oxygen in OH is identified as the O 2 gas, not oxygen from the ethoxy groups on TEOS. With these data, the role of OH in deposition of SiO 2 from TEOS-based plasmas and the effects of plasma deposition parameters on film formation are discussed.

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Section: Introductionmentioning

confidence: 99%

“…19 Here, we expand our characterization of OH in TEOS-based plasmas to include reactivity measurements as a function of P and T S . We also determine Θ T and Θ R for OH and the effect of P on OH radical energies.…”

Section: Introductionmentioning

confidence: 99%

Effects of Plasma Processing Parameters on the Surface Reactivity of OH(X²Π) in Tetraethoxysilane/O₂ Plasmas during Deposition of SiO₂

1997

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“…15,17 We have previously examined wider spectral ranges and find that excitation data taken in this limited wavelength range are representative of the OH population. 18,19 For reactivity measurements, the plasma molecular beam was collimated by two slits, 1.0 and 1.25 mm wide, with the second slit located 12 mm downstream from the first slit. The first slit was mounted on a liquid N 2 cold shield to minimize desorption of molecules from the slit surface.…”

Section: Methodsmentioning

confidence: 99%

“…17 We have previously investigated the source and role of OH in a film deposition system, specifically PECVD of SiO 2 , using a 20:80 TEOS/O 2 system. 18,19 With the TEOS/O 2 system, the surface reactivity of OH on a 300 K Si substrate was 0.41 ( 0.04 and was unaffected by changing the applied rf plasma power (P). Interestingly, R decreased significantly as the substrate temperature was increased, reaching 0.15 at T s > 350 K. This was attributed to a decrease in reaction partners such as the silanol group (-SiOH) or H atoms on the surface at higher T s .…”

Section: Introductionmentioning

confidence: 99%

Surface Reactivity of OH Molecules during Deposition of SiO₂ from Siloxane-Based Plasmas

Zhang

Fisher

2004

J. Phys. Chem. B

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The surface interactions of OH(X 2 Π) radicals during SiO 2 deposition from 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS)/oxidant (O 2 or N 2 O) and dimethyldimethoxysilane (DMDMOS)/oxidant (O 2 or N 2 O) plasmas have been measured by using the imaging of radicals interacting with surfaces (IRIS) method. The reactivity of OH at the surface of a growing SiO 2 film has been determined as a function of the applied rf plasma power (P), the precursor-to-oxidant ratio, and the substrate temperature (T s ). For both Si precursors, the surface reactivity (R) of OH during SiO 2 deposition on a 300 K Si substrate is ∼0.60 and is unaffected by changing precursor:oxidant ratio but does increase slightly with P. In contrast, at higher substrate temperatures (T s > 350 K), R decreases to 0.16 ( 0.10 for 1:10 TMCTS/O 2 plasma (P ) 100 W) and to 0.42 ( 0.03 for 1:10 DMDMOS/O 2 plasma (P ) 100 W). The rotational (Θ R ) and translational (Θ T ) temperatures of the OH radicals have also been determined. The formation and role of OH in SiO 2 deposition are discussed and compared with previous results for TEOS/O 2 plasmas.

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“…The oxygen needed for the formation of SiO 2 is provided by both H 2 O molecules and OH radicals. Bogart et al [47], in a study of plasma deposition of silica, detected hydroxyl radicals in the plasma and measured a significant surface reactivity for OH. This suggests that OH might play an important role in the deposition of SiO 2 .…”

Section: Heterogeneous Chemistry Mechanismmentioning

confidence: 99%

Functionally Graded Alumina/Mullite Coatings for Protection of Silicon Carbide Ceramic Components From Corrosion

Sotirchos¹

2001

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ii EXECUTIVE SUMMARYThe main objective of this research project was the formulation of processes that can be used to prepare compositionally graded alumina/mullite coatings for protection from corrosion of silicon carbide components (monolithic or composite) used or proposed to be used in coal utilization systems (e.g., combustion chamber liners, heat exchanger tubes, particulate removal filters, and turbine components) and other energy-related applications. Since alumina has excellent resistance to corrosion but coefficient than silicon carbide, the key idea of this project has been to develop graded coatings with composition varying smoothly along their thickness between an inner (base) layer of mullite in contact with the silicon carbide component and an outer layer of pure alumina, which would function as the actual protective coating of the component. (Mullite presents very good adhesion towards silicon carbide and has thermal expansion coefficient very close to that of the latter.)A comprehensive investigation of the chemical vapor codeposition (CVD) of alumina and mullite through hydrolysis of aluminum and silicon chlorides in the presence of CO 2 and H 2 as a route for the preparation of composite alumina/mullite coatings was carried out. The kinetics of the codeposition of silica, alumina, and aluminosilicates from mixtures of methyltrichlorosilane or silicon tetrachloride, aluminum trichloride, carbon dioxide, and hydrogen was studied experimentally. In order to elucidate some aspects of the codeposition process, the deposition of pure silica and the deposition of pure alumina from mixtures of methyltrichlorosilane or silicon tetrachloride and aluminum trichloride, respectively, with CO 2 and H 2 were also investigated. Kinetic data were obtained by carrying out chemical vapor deposition experiments on SiC substrates in a hot-wall reactor of tubular geometry, which permits continuous monitoring of the deposition rate through the use of a microbalance. Experiments were conducted over relatively broad temperature and pressure ranges around 1300 K and 100 Torr, respectively, and the effects of feed composition, flow rate, and distance from the entrance of the reactor on the deposition rate and deposit composition were investigated. Thermodynamic equilibrium computations were performed on the Al/Si/Cl/C/O/H, Al/Cl/C/O/H, and Si/Cl/C/O/H systems at the conditions used in the deposition experiments, and the results were used to explain the observations made in the experiments. Among the most interesting findings of the kinetic studies was that in the codeposition problem there was a dramatic increase of the deposition rate of SiO2 in the codeposition process, relative to the rate seen in a silica deposition experiment through the hydrolysis of silicon chloride at the same conditions. This enhancement was accompanied by a reduction of the rate of deposition of Al 2 O 3 , relative to the deposition rate in an independent alumina deposition experiment at the same conditions. The overall deposition rate was by a...

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Surface reactivity measurements for OH radicals during deposition of SiO2 from tetraethoxysilane/O2 plasmas

Cited by 24 publications

References 20 publications

Effects of Plasma Processing Parameters on the Surface Reactivity of OH(X²Π) in Tetraethoxysilane/O₂ Plasmas during Deposition of SiO₂

Effects of Plasma Processing Parameters on the Surface Reactivity of OH(X²Π) in Tetraethoxysilane/O₂ Plasmas during Deposition of SiO₂

Surface Reactivity of OH Molecules during Deposition of SiO₂ from Siloxane-Based Plasmas

Functionally Graded Alumina/Mullite Coatings for Protection of Silicon Carbide Ceramic Components From Corrosion

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Surface reactivity measurements for OH radicals during deposition of SiO2 from tetraethoxysilane/O2 plasmas

Cited by 24 publications

References 20 publications

Effects of Plasma Processing Parameters on the Surface Reactivity of OH(X2Π) in Tetraethoxysilane/O2 Plasmas during Deposition of SiO2

Effects of Plasma Processing Parameters on the Surface Reactivity of OH(X2Π) in Tetraethoxysilane/O2 Plasmas during Deposition of SiO2

Surface Reactivity of OH Molecules during Deposition of SiO2 from Siloxane-Based Plasmas

Functionally Graded Alumina/Mullite Coatings for Protection of Silicon Carbide Ceramic Components From Corrosion

Contact Info

Product

Resources

About

Effects of Plasma Processing Parameters on the Surface Reactivity of OH(X²Π) in Tetraethoxysilane/O₂ Plasmas during Deposition of SiO₂

Effects of Plasma Processing Parameters on the Surface Reactivity of OH(X²Π) in Tetraethoxysilane/O₂ Plasmas during Deposition of SiO₂

Surface Reactivity of OH Molecules during Deposition of SiO₂ from Siloxane-Based Plasmas