Molybdenum carbonitride deposited by plasma atomic layer deposition as a Schottky contact to gallium nitride

Molina, Alex; Campbell, Ian E.; Walter, Timothy N.; Agyapong, Ama Duffie; Mohney, Suzanne E.

doi:10.1063/5.0062140

Cited by 5 publications

(2 citation statements)

References 28 publications

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“…Molybdenum(VI) bis(imido) compounds have a wide range of applications, including their use as olefin metathesis catalysts, , oxygen atom transfer reagents, − and vapor-phase deposition precursors. − The reactivity of these industrially relevant compounds has been extensively studied, but the mechanism of their thermal decomposition remains poorly understood. Both the temperature at which and the mechanism by which a compound decomposes must be understood so that the primary decomposition pathways can be blocked effectively through ligand and complex design to enhance thermal stability. − Understanding the thermal decomposition of compounds is particularly relevant to chemical vapor deposition (CVD) and atomic layer deposition (ALD) .…”

Section: Introductionmentioning

confidence: 99%

Origin of Decomposition in a Family of Molybdenum Precursor Compounds

et al. 2022

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The bis(tert-butylimido)-molybdenum(VI) framework has been used successfully in the design of vapor-phase precursors for molybdenum-containing thin films, so understanding its thermal behavior is important for such applications. Here, we report the thermal decomposition mechanism for a series of volatile bis(alkylimido)-dichloromolybdenum(VI) adducts with neutral N,N′-chelating ligands, to probe the stability and decomposition pathways for these molecules. The alkyl groups explored were tert-butyl, tert-pentyl, 1-adamantyl, and a cyclic imido (from 2,5-dimethylhexane-2,5-diamine). We also report the synthesis of the new tert-octyl imido adducts, ( t OctN)2MoCl2·L (L = N,N,N′,N′-tetramethylethylenediamine or 2,2′-bipyridine), which have been fully characterized by spectroscopic techniques as well as single-crystal X-ray diffraction and thermal analysis. We found that the decomposition of all compounds follows the same general pathway, proceeding first by the dissociation of the chelating ligand to give the coordinatively unsaturated species (RN)2MoCl2. Subsequent dimerization results in either an imido bridged adduct, [(RN)Mo(μ-NR)Cl2]2, or a chloride bridged adduct, [(RN)2Mo(μ-Cl)Cl]2, depending on the size of the R group. The dimeric species then likely undergoes an intramolecular γ-hydrogen transfer to yield a nitrido-amido adduct, (RHN)MoNCl2, and an alkene. Ultimately, the resulting molybdenum species appears to decompose into free tert-alkylamine and Mo2N or Mo2C. The thermolysis reactions have been monitored using 1H NMR spectroscopy, and the volatile decomposition products were analyzed using gas chromatography–mass spectrometry. A key intermediate has also been detected using electron ionization high-resolution mass spectrometry. Finally, a detailed computational investigation supports the mechanism outlined above and helps explain the relative stabilities of different N,N′-chelated bis(alkylimido)-dichloromolybdenum(VI) adducts.

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Section: Introductionmentioning

confidence: 99%

Origin of Decomposition in a Family of Molybdenum Precursor Compounds

et al. 2022

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“…Molybdenum(VI) bis(imido) compounds have a wide range of applications, including their use as olefin metathesis catalysts, 89,90 oxygen atom transfer reagents, [91][92][93][94] and vapor phase deposition precursors. 36,76,84,104,[121][122][123][124][128][129][130][131][132][135][136][137][138][139][141][142][143][144][145][146]169,[171][172][173][174][175][176][177]180,[231][232][233] The reactivity of these industrially relevant compounds has been extensively studied, but the mechanism of their thermal decomposition remains poorly understood. Both the temperature at which and the mechanism by which a compound decomposes must be understood so that the primary decomposition pathways can be blocked effectively through ligand and complex design to enhance thermal stability.…”

Section: Introductionmentioning

confidence: 99%