Infrared Spectra of Metal Chelate Compounds. III. Infrared Spectra of Acetylacetonates of Divalent Metals<sup>1</sup>

Nakamoto, Kazuo; McCarthy, Paul J.; Martell, Arthur E.

doi:10.1021/ja01467a003

Cited by 197 publications

(59 citation statements)

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“…These vibrational features are derived from the acetylacetonate (acac) constituents. 46 * and acacH * . To estimate the coverage of Sn(acac) 2 * species on the surface, the sites on the HfO 2 surface can be approximated using the HfO 2 density of 9.6 g/cm 3 .…”

Section: Ftir Spectroscopy Measurements-in Situ Ftir Spectra Of Hfo mentioning

confidence: 99%

Atomic Layer Etching of HfO₂Using Sequential, Self-Limiting Thermal Reactions with Sn(acac)₂and HF

Lee

DuMont

George

2015

ECS J. Solid State Sci. Technol.

118

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The atomic layer etching (ALEt) of HfO 2 was performed using sequential, self-limiting thermal reactions with tin(II) acetylacetonate (Sn(acac) 2 ) and HF as the reactants. The HF source was a HF-pyridine solution. The etching of HfO 2 was linear with atomic level control versus number of Sn(acac) 2 and HF reaction cycles. The HfO 2 ALEt was measured at temperatures from 150-250 • C. Quartz crystal microbalance (QCM) measurements determined that the mass change per cycle (MCPC) increased with temperature from −6.7 ng/(cm 2 cycle) at 150 • C to −11.2 ng/(cm 2 cycle) at 250 • C. These MCPC values correspond to etch rates from 0.070 Å/cycle at 150 • C to 0.117 Å/cycle at 250 • C. X-ray reflectivity analysis confirmed the linear removal of HfO 2 and measured an HfO 2 ALEt etch rate of 0.11 Å/cycle at 200 • C. Fourier transform infrared (FTIR) spectroscopy measurements also observed HfO 2 ALEt using the infrared absorbance of the Hf-O stretching vibration. FTIR analysis also revealed absorbance features consistent with HfF 4 or HfF x surface species as a reaction intermediate. The HfO 2 etching is believed to follow the reaction: HfO 2 + 4Sn(acac) 2 + 4HF → Hf(acac) 4 + 4SnF(acac) + 2H 2 O. In the proposed reaction mechanism, Sn(acac) 2 donates acac to the substrate to produce Hf(acac) 4 . HF allows SnF(acac) and H 2 O to leave as reaction products. The thermal ALEt of many other metal oxides, as well as metal nitrides, phosphides, sulfides and arsenides, should be possible by a similar mechanism. Atomic layer etching (ALEt) is a thin film removal technique based on sequential, self-limiting surface reactions.1-3 ALEt can be viewed as the reverse of atomic layer deposition (ALD). 4 ALEt is able to remove thin films with atomic layer control. ALD and ALEt are able to provide the necessary processing techniques for surface engineering at the atomic level. 5,6 This atomic level control is needed for the nanofabrication of a wide range of nanoscale devices. 7Until recently, ALEt processes have been reported using only ionenhanced or energetic noble gas atom-enhanced surface reactions. [1][2][3] In these ALEt processes, a halogen is adsorbed on the surface of the material. Subsequently, ion or noble gas atom bombardment is used to desorb halogen compounds that etch the material. Using this approach, ALEt has been reported for Si,2,3,[8][9][10][11][12] Ge, 6,13 and compound semiconductors.14-17 ALEt has also been demonstrated for a variety of metal oxides. 7,[18][19][20] Additional ALEt studies have been conducted on various carbon substrates. 21-23The ALEt of Al 2 O 3 was recently reported using sequential, selflimiting thermal reactions with Sn(acac) 2 and HF as the reactants. 24The linear removal of Al 2 O 3 was observed at temperatures from 150-250• C without the use of ion or noble gas atom bombardment. Al 2 O 3 ALEt etch rates varied with temperature from 0.14 Å/cycle at 150• C to 0.61 Å/cycle at 250• C. 24 The Sn(acac) 2 and HF thermal reactions were both self-limiting versus reactant exposure. In addition, the Al 2...

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Section: Ftir Spectroscopy Measurements-in Situ Ftir Spectra Of Hfo mentioning

confidence: 99%

Atomic Layer Etching of HfO₂Using Sequential, Self-Limiting Thermal Reactions with Sn(acac)₂and HF

Lee

DuMont

George

2015

ECS J. Solid State Sci. Technol.

118

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“…The weak band in the region 40W75 cm-' (for which there are no corresponding ligand bands) is assigned to pure Fe-0 stretching vibration. Nakamoto et al (18,19) also observed a weak band for M-0 stretching frequency and gave the assignment for this band in the region 430490 cm-l. The band in the region 538-585 cm-l has been assigned as a combination band of metaloxygen stretching frequency and C-C bending vibration (18,19), or 0-C-0 bending (34), or N-C-0 bending (16).…”

Section: Infrared Study Amide Complexesmentioning

confidence: 91%

Reactions of iron carbonyls with various ligands in the presence of chloroform. A new method for the preparation of iron halide complexes

Singh¹,

Rivest²

1968

Can. J. Chem.

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Iron halidecomplexes ofthe type FeCI2.2L (L = CH3CONH2, HCONH2, HCONHCH3) and FeC13.L (L = (C6HS)3P, (C6H5)3A~, CsH5NH2, C6H5CONH2) have been prepared by the reaction of iron carbonyls with various ligands in chloroform as solvent. The mechanism of the reaction and the effect of other solvents have also been studied. The magnetic susceptibility measurements and infrared spectral study (4000-200 cm-') suggest that these complexes have tetrahedral configuration. The possible site of bonding in ligands and infrared assignments for Fe-0, Fe-Cl, Fe-N, Fe-P, Fe-As bands have been given. The relative Fe-0 bond strengths in various amide complexes have been determined on the basis of metal-oxygen stretching frequency and of shifts in carbonyl stretching frequency.

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“…The strong absorption bands at about 2900 cm -1 were assigned to the olefinic C-H stretching bands. While the bands appearing at 1400 ~ 1600 cm -1 were characteristics of the metal chelate compounds with carbonyl groups [22,23]. Two strong peaks at 1550 and 1450 cm -1 w e r e m a i n l y a s s i g n e d t o t h e C = O asymmetric and symmetric stretching modes, respectively.…”

Section: Methodsmentioning

confidence: 98%

“…The precursor should consist of organometallic composites derived from starting materials. The IR spectrum indicated the clear bands assigned to C-H stretching (~2900 cm -1 ) and C-O stretching (1400~1600 cm -1 ) of organic substances [22,23]. With increasing the heat-treatment temperature, the intensities of initial bands steeply decreased and a new band assigned to Fe-O stretching (~600 cm -1 ) started to appear at 325°C.…”

Section: Formation Of Lafeo3 Nanoparticlesmentioning

confidence: 99%

Superparamagnetic Behaviour and Induced Ferrimagnetism of LaFeO3 Nanoparticles Prepared by a Hot-Soap Technique

Fujii¹,

Matsusue²,

Takada³

2012

Advanced Aspects of Spectroscopy

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Infrared Spectra of Metal Chelate Compounds. III. Infrared Spectra of Acetylacetonates of Divalent Metals¹

Cited by 197 publications

References 0 publications

Atomic Layer Etching of HfO₂Using Sequential, Self-Limiting Thermal Reactions with Sn(acac)₂and HF

Atomic Layer Etching of HfO₂Using Sequential, Self-Limiting Thermal Reactions with Sn(acac)₂and HF

Reactions of iron carbonyls with various ligands in the presence of chloroform. A new method for the preparation of iron halide complexes

Superparamagnetic Behaviour and Induced Ferrimagnetism of LaFeO3 Nanoparticles Prepared by a Hot-Soap Technique

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Infrared Spectra of Metal Chelate Compounds. III. Infrared Spectra of Acetylacetonates of Divalent Metals1

Cited by 197 publications

References 0 publications

Atomic Layer Etching of HfO2Using Sequential, Self-Limiting Thermal Reactions with Sn(acac)2and HF

Atomic Layer Etching of HfO2Using Sequential, Self-Limiting Thermal Reactions with Sn(acac)2and HF

Reactions of iron carbonyls with various ligands in the presence of chloroform. A new method for the preparation of iron halide complexes

Superparamagnetic Behaviour and Induced Ferrimagnetism of LaFeO3 Nanoparticles Prepared by a Hot-Soap Technique

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Infrared Spectra of Metal Chelate Compounds. III. Infrared Spectra of Acetylacetonates of Divalent Metals¹

Atomic Layer Etching of HfO₂Using Sequential, Self-Limiting Thermal Reactions with Sn(acac)₂and HF

Atomic Layer Etching of HfO₂Using Sequential, Self-Limiting Thermal Reactions with Sn(acac)₂and HF