Volatile Hexavalent Oxo-amidinate Complexes: Molybdenum and Tungsten Precursors for Atomic Layer Deposition

Aidan R. Mouat; Anil U. Mane; Jeffrey W. Elam; Massimiliano Delferro; Tobin J. Marks; Peter C. Stair

doi:10.1021/acs.chemmater.6b00248

Volatile Hexavalent Oxo-amidinate Complexes: Molybdenum and Tungsten Precursors for Atomic Layer Deposition

Aidan R. Mouat, Anil U. Mane, Jeffrey W. Elam, Massimiliano Delferro^*, Tobin J. Marks, Peter C. Stair

^*Corresponding author for this work

Chemistry

Research output: Contribution to journal › Article › peer-review

51 Scopus citations

Abstract

New complexes MoO₂(^tBuAMD)₂ (1) and WO₂(^tBuAMD)₂ (2) (AMD = acetamidinato) are synthesized and fully characterized as precursors for atomic layer deposition (ALD). They contain metal-oxo functionalities not previously utilized in ALD-type growth processes and are fully characterized by ¹H and ¹³C NMR, X-ray diffraction (XRD), Fourier transform infrared, thermogravimetric analysis, single-crystal XRD, and elemental analysis. Guided by quartz-crystal microbalance studies, ALD growth methodologies for both complexes have been developed. Remarkably, these isostructural compounds exhibit dramatic differences in ALD properties. Using 1 and O₃, amorphous, ultrathin molybdenum oxynitride (MoON) films are grown on Si(100) wafers. Using 2 and H₂O yields amorphous WO₃ films on Si(100) wafers that crystallize as WO₃ nanowires upon annealing. Although 1/H₂O and 2/O₃ growth was attempted, effective ALD growth could only be obtained with 1/O₃ and 2/H₂O, underscoring reactivity differences in these precursors. Film thicknesses, compositions, and optical and electrical parameters are characterized by variable angle spectroscopic ellipsometry, X-ray reflectivity, grazing incidence X-ray diffraction, X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, and atomic force microscopy techniques. The hitherto unknown ALD chemistry of group VI metal-oxo compounds lays a foundation for their use in the ALD synthesis of heterogeneous catalysts.

Original language	English (US)
Pages (from-to)	1907-1919
Number of pages	13
Journal	Chemistry of Materials
Volume	28
Issue number	6
DOIs	https://doi.org/10.1021/acs.chemmater.6b00248
State	Published - Mar 22 2016

Funding

The NUANCE Center is supported by the MRSEC program (NSF DMR- 1121262) at the Materials Research Center, the Keck Foundation, the International Institute for Nanotechnology (IIN), the State of Illinois, through the IIN, and Northwestern University. The J. B. Cohen X-ray diffraction facility is supported by the MRSEC program of the National Science Foundation (Grant DMR-1121262) at the Materials Research Center of Northwestern University. Purchase of the NMR instrumentation at the Integrated Molecular Structure Education and Research Center (IMSERC) at Northwestern was supported by the National Science Foundation (Grant CHE- 1048773).

ASJC Scopus subject areas

General Chemistry
General Chemical Engineering
Materials Chemistry

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10.1021/acs.chemmater.6b00248

Cite this

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title = "Volatile Hexavalent Oxo-amidinate Complexes: Molybdenum and Tungsten Precursors for Atomic Layer Deposition",

abstract = "New complexes MoO2(tBuAMD)2 (1) and WO2(tBuAMD)2 (2) (AMD = acetamidinato) are synthesized and fully characterized as precursors for atomic layer deposition (ALD). They contain metal-oxo functionalities not previously utilized in ALD-type growth processes and are fully characterized by 1H and 13C NMR, X-ray diffraction (XRD), Fourier transform infrared, thermogravimetric analysis, single-crystal XRD, and elemental analysis. Guided by quartz-crystal microbalance studies, ALD growth methodologies for both complexes have been developed. Remarkably, these isostructural compounds exhibit dramatic differences in ALD properties. Using 1 and O3, amorphous, ultrathin molybdenum oxynitride (MoON) films are grown on Si(100) wafers. Using 2 and H2O yields amorphous WO3 films on Si(100) wafers that crystallize as WO3 nanowires upon annealing. Although 1/H2O and 2/O3 growth was attempted, effective ALD growth could only be obtained with 1/O3 and 2/H2O, underscoring reactivity differences in these precursors. Film thicknesses, compositions, and optical and electrical parameters are characterized by variable angle spectroscopic ellipsometry, X-ray reflectivity, grazing incidence X-ray diffraction, X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, and atomic force microscopy techniques. The hitherto unknown ALD chemistry of group VI metal-oxo compounds lays a foundation for their use in the ALD synthesis of heterogeneous catalysts.",

author = "Mouat, {Aidan R.} and Mane, {Anil U.} and Elam, {Jeffrey W.} and Massimiliano Delferro and Marks, {Tobin J.} and Stair, {Peter C.}",

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T2 - Molybdenum and Tungsten Precursors for Atomic Layer Deposition

AU - Mouat, Aidan R.

AU - Mane, Anil U.

AU - Elam, Jeffrey W.

AU - Delferro, Massimiliano

AU - Marks, Tobin J.

AU - Stair, Peter C.

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N2 - New complexes MoO2(tBuAMD)2 (1) and WO2(tBuAMD)2 (2) (AMD = acetamidinato) are synthesized and fully characterized as precursors for atomic layer deposition (ALD). They contain metal-oxo functionalities not previously utilized in ALD-type growth processes and are fully characterized by 1H and 13C NMR, X-ray diffraction (XRD), Fourier transform infrared, thermogravimetric analysis, single-crystal XRD, and elemental analysis. Guided by quartz-crystal microbalance studies, ALD growth methodologies for both complexes have been developed. Remarkably, these isostructural compounds exhibit dramatic differences in ALD properties. Using 1 and O3, amorphous, ultrathin molybdenum oxynitride (MoON) films are grown on Si(100) wafers. Using 2 and H2O yields amorphous WO3 films on Si(100) wafers that crystallize as WO3 nanowires upon annealing. Although 1/H2O and 2/O3 growth was attempted, effective ALD growth could only be obtained with 1/O3 and 2/H2O, underscoring reactivity differences in these precursors. Film thicknesses, compositions, and optical and electrical parameters are characterized by variable angle spectroscopic ellipsometry, X-ray reflectivity, grazing incidence X-ray diffraction, X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, and atomic force microscopy techniques. The hitherto unknown ALD chemistry of group VI metal-oxo compounds lays a foundation for their use in the ALD synthesis of heterogeneous catalysts.

AB - New complexes MoO2(tBuAMD)2 (1) and WO2(tBuAMD)2 (2) (AMD = acetamidinato) are synthesized and fully characterized as precursors for atomic layer deposition (ALD). They contain metal-oxo functionalities not previously utilized in ALD-type growth processes and are fully characterized by 1H and 13C NMR, X-ray diffraction (XRD), Fourier transform infrared, thermogravimetric analysis, single-crystal XRD, and elemental analysis. Guided by quartz-crystal microbalance studies, ALD growth methodologies for both complexes have been developed. Remarkably, these isostructural compounds exhibit dramatic differences in ALD properties. Using 1 and O3, amorphous, ultrathin molybdenum oxynitride (MoON) films are grown on Si(100) wafers. Using 2 and H2O yields amorphous WO3 films on Si(100) wafers that crystallize as WO3 nanowires upon annealing. Although 1/H2O and 2/O3 growth was attempted, effective ALD growth could only be obtained with 1/O3 and 2/H2O, underscoring reactivity differences in these precursors. Film thicknesses, compositions, and optical and electrical parameters are characterized by variable angle spectroscopic ellipsometry, X-ray reflectivity, grazing incidence X-ray diffraction, X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, and atomic force microscopy techniques. The hitherto unknown ALD chemistry of group VI metal-oxo compounds lays a foundation for their use in the ALD synthesis of heterogeneous catalysts.

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Volatile Hexavalent Oxo-amidinate Complexes: Molybdenum and Tungsten Precursors for Atomic Layer Deposition

Abstract

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CCDC 1473009: Experimental Crystal Structure Determination

CCDC 1473008: Experimental Crystal Structure Determination

CCDC 1473007: Experimental Crystal Structure Determination

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Volatile Hexavalent Oxo-amidinate Complexes: Molybdenum and Tungsten Precursors for Atomic Layer Deposition

Abstract

Funding

ASJC Scopus subject areas

Access to Document

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Datasets

CCDC 1473009: Experimental Crystal Structure Determination

CCDC 1473008: Experimental Crystal Structure Determination

CCDC 1473007: Experimental Crystal Structure Determination

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