A thermogravimetric study of the fluorination of zirconium and hafnium oxides with anhydrous hydrogen fluoride gas

Vilakazi, Bernard M.; Monnahela, Oduetse S.; Wagener, J. B.; Carstens, P. A. B.; Ntsoane, T.P.

doi:10.1016/j.jfluchem.2012.06.012

Cited by 10 publications

(11 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…• C. 48 In addition, HfF 4 was not observed as a product by X-ray diffraction analysis until higher temperatures between 450-580…”

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

confidence: 99%

“…In contrast, slow fluorination kinetics of bulk HfO 2 were observed during HF exposures. 48 Thermogravimetric studies showed that bulk HfO 2 did not begin fluorination under HF exposure until >350…”

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

confidence: 99%

“…• C. 48 The fluorination of the HfO 2 surface occurs much more readily than the fluorination of bulk HfO 2 substrates.…”

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

confidence: 99%

See 2 more Smart Citations

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

View full text Add to dashboard Cite

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...

show abstract

“…• C. 48 In addition, HfF 4 was not observed as a product by X-ray diffraction analysis until higher temperatures between 450-580…”

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

confidence: 99%

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

confidence: 99%

See 1 more Smart Citation

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

View full text Add to dashboard Cite

show abstract

“…The proposed mechanism of mesoporosity development for UiO‐66 materials stem from ZrO bond breakage from fluorocarbon radicals generated in the plasma is similar to reaction with hydrogen fluoride 19. This is evidenced by the atomic ratios shown in Tables 2 and S3 in the Supporting Information.…”

Section: Surface Area (Sa) and Pore Volume (Pv) Of Materialsmentioning

confidence: 77%

“…The proposed mechanism of mesoporosity development for UiO-66 materials stem from ZrÀOb ond breakage from fluorocarbon radicals generated in the plasma is similart or eaction with hydrogen fluoride. [19] This is evidencedb yt he atomic ratios shown in Ta bles 2a nd S3 in the Supporting Information. The F/Zr atomic ratio increases with increasing treatment time, whereas the O/Zr ratio decreases with increasing treatment time, indicating loss of oxygen species due to bond breaking from plasma treatment.…”

mentioning

confidence: 71%

Hierarchical Pore Development by Plasma Etching of Zr‐Based Metal–Organic Frameworks

DeCoste

Rossin

Peterson

2015

Chemistry A European J

View full text Add to dashboard Cite

The typically stable Zr-based metal-organic frameworks (MOFs) UiO-66 and UiO-66-NH2 were treated with tetrafluoromethane (CF4 ) and hexafluoroethane (C2 F6 ) plasmas. Through interactions between fluoride radicals from the perfluoroalkane plasma and the zirconium-oxygen bonds of the MOF, the resulting materials showed the development of mesoporosity, creating a hierarchical pore structure. It is anticipated that this strategy can be used as a post-synthetic technique for developing hierarchical networks in a variety of MOFs.

show abstract

Effect of YSZ composite ceramics with different LaF3 doping content on microstructure evolution and infrared emissivity

Xiang,

Zhou,

Yin

et al. 2024

Ceramics International

View full text Add to dashboard Cite

A thermogravimetric study of the fluorination of zirconium and hafnium oxides with anhydrous hydrogen fluoride gas

Cited by 10 publications

References 15 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

Hierarchical Pore Development by Plasma Etching of Zr‐Based Metal–Organic Frameworks

Effect of YSZ composite ceramics with different LaF3 doping content on microstructure evolution and infrared emissivity

Contact Info

Product

Resources

About

A thermogravimetric study of the fluorination of zirconium and hafnium oxides with anhydrous hydrogen fluoride gas

Cited by 10 publications

References 15 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

Hierarchical Pore Development by Plasma Etching of Zr‐Based Metal–Organic Frameworks

Effect of YSZ composite ceramics with different LaF3 doping content on microstructure evolution and infrared emissivity

Contact Info

Product

Resources

About

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