Trends in precursor selection for MOCVD

Maury, F.

doi:10.1002/cvde.19960020306

Cited by 55 publications

(37 citation statements)

References 17 publications

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“…In the present work, the gaseous chemical species CH, CH 2 , CH 3 , CH 4 2 (N x C 1Àx ) and C were considered in the calculations. Their thermodynamic data were taken from a databank.…”

Section: Thermochemical Calculationsmentioning

confidence: 99%

“…Thus, a single-source precursor allows a good control of the gas-phase composition up to the deposition zone and is useful for simplification of the reactor design and processing conditions. However, it appears from a recent critical review on the stringent requirements for metal-organic compounds suitable for MOCVD processes 2 that progress in the design of metal-organic precursors, and thence further development of MOCVD, both strongly depend on the knowledge of growth mechanisms. The thermal decomposition of metal-organic compounds can take place according to numerous mechanisms and a crucial problem is to control the reaction pathway which leads from the precursor to the thin film.…”

Section: Introductionmentioning

confidence: 98%

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Low-temperature MOCVD of chromium carbonitride coatings from tetrakis(diethylamido)chromium and pyrolysis mechanism of this single-source precursor

Maury

Ossola

1998

Appl. Organometal. Chem.

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Amorphous chromium carbonitride coatings with a low nitrogen content (3–8 at%) were deposited by low‐pressure MOCVD in the temperature range 573–793 K using Cr(NEt2)4 as single‐source precursor. This poor nitrogen incorporation is in agreement with the trends predicted by thermochemical calculations. XPS data, resistivity measurements and annealing experiments suggest that the films grown at 573 K are contaminated by organic species due to incomplete elimination of the ligands. The films deposited at higher temperature crystallize upon annealing at 873 K to form an orthorhombic ternary chromium carbonitride phase. The major volatile by‐products of the MOCVD reaction were analyzed by 1H and 13C NMR. Their amount and the quasi‐equimolar EtN=CHMe/HNEt2 ratio suggest that most of the NEt2 ligands are removed by a stepwise mechanism which probably occurs with other diethylamido complexes of transition metals when they are used as single‐source precursors in MOCVD. The incorporation of the metalloid elements in the film is discussed in comparison with recent literature data. © 1998 John Wiley & Sons, Ltd.

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“…In the present work, the gaseous chemical species CH, CH 2 , CH 3 , CH 4 2 (N x C 1Àx ) and C were considered in the calculations. Their thermodynamic data were taken from a databank.…”

Section: Thermochemical Calculationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Low-temperature MOCVD of chromium carbonitride coatings from tetrakis(diethylamido)chromium and pyrolysis mechanism of this single-source precursor

Maury

Ossola

1998

Appl. Organometal. Chem.

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“…Two precursors were selected for chemical stability and low toxicity [12]. Trimethyl(methylcyclopentadienyl)platinum(IV), commonly referred to as MeCpPtMe 3 (Abcr) is widely used ( [8,9,[13][14][15]), relatively volatile ( [16]), and rather expensive.…”

Section: Cvd Precursorsmentioning

confidence: 99%

On the Activity Enhancing Role of Iron Oxide for Noble Metal Oxidation Catalysts: A CVD-Based Study with Differently Structured Combinations of Pt and FeOx Coatings on Al2O3

et al. 2018

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Abstract:With regard to the catalysis of oxidation reactions by noble metals, the addition of FeO x to an Al 2 O 3 -supported Pt catalyst is known to be energetically more favorable compared to only Pt. In this work, different process routes for the preparation of such Fe-promoted Pt/Al 2 O 3 catalysts via atmospheric chemical vapor deposition (CVD) in a fluidized bed were explored. Specifically, the question of whether it would be advantageous to deposit the Fe before, along with, or after the Pt was addressed, and new information was obtained about the optimum FeO x -Pt interface and mixing ratio. Vapors of Trimethyl(methylcyclopentadienyl)platinum(IV) and/or Ethyl-ferrocene were injected into the bed from the top, permitting a quasi-lossless precursor operation and a very good control of the deposited metal, and hence of the catalyst structure. Samples could be extracted from the top while CVD was ongoing to obtain time-resolved data. The catalytic activity was determined through CO oxidation. The Fe-Pt mixing ratio was then varied for the most active deposition sequence, in order to identify an activity optimum generated by the minimum amount of Pt catalyst. When compared to pure Pt/Al 2 O 3 , the optimum catalyst consistently showed superior performance even after thermal stress.

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“…24 Among the various physicochemical properties, good volatility, non-toxicity and thermal stability during the sublimation step are considered essential properties for FBMOCVD. The processing conditions require compounds easily available in good yields, and deposition temperatures below 150°C.…”

Section: Choice Of the Precursorsmentioning

confidence: 99%

MOCVD of rhodium, palladium and platinum complexes on fluidized divided substrates: Novel process for one-step preparation of noble-metal catalysts

Hierso

Serp

Feurer

et al. 1998

Appl. Organometal. Chem.

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A new one‐step method, entitled fluidized‐bed metal‐organic chemical vapor deposition (FBMOCVD) of preparing highly dispersed metal‐supported catalysts is reported. The following complexes were studied and used as CVD precursors in presence of H2: [Rh(μ‐Cl)(CO)2]2, Rh(allyl)3, Rh(acac)(CO)2, Pd(allyl)(hfac), Pd(allyl)(Cp), Pt(COD)(CH3)2. (acac, acetylacetonato; hfac, hexafluoroacetylacetonato; Cp, cyclopentadienyl; COD, cyclooctadienyl). In a first approach, depositions on planar substrates were carried out to establish the best experimental conditions to obtain good‐quality deposits. X‐ray diffraction, X‐ray photo‐electron spectroscopy and electron microprobe studies were realized on the resulting thin films. Analyses of the products contained in the gas phase after and during deposition were performed by mass spectrometry and GC–MS. Finally, catalysts prepared by FBMOCVD were characterized by transmission electron microscopy–energy dispersion spectroscopy (TEM–EDS), metal‐loading determinations and specific‐surface measurements (BET). Dispersed nanosized aggregates were obtained, showing high activities in alkene hydrogenation and alcohol hydrocarbonylation. © 1998 John Wiley & Sons, Ltd.

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Trends in precursor selection for MOCVD

Cited by 55 publications

References 17 publications

Low-temperature MOCVD of chromium carbonitride coatings from tetrakis(diethylamido)chromium and pyrolysis mechanism of this single-source precursor

Low-temperature MOCVD of chromium carbonitride coatings from tetrakis(diethylamido)chromium and pyrolysis mechanism of this single-source precursor

On the Activity Enhancing Role of Iron Oxide for Noble Metal Oxidation Catalysts: A CVD-Based Study with Differently Structured Combinations of Pt and FeOx Coatings on Al2O3

MOCVD of rhodium, palladium and platinum complexes on fluidized divided substrates: Novel process for one-step preparation of noble-metal catalysts

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