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Steven M. George - One of the best experts on this subject based on the ideXlab platform.
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Effect of crystallinity on thermal atomic layer etching of hafnium Oxide, Zirconium Oxide, and hafnium Zirconium Oxide
Journal of Vacuum Science and Technology, 2020Co-Authors: Jessica A. Murdzek, Steven M. GeorgeAbstract:Thermal atomic layer etching (ALE) can be achieved using sequential, self-limiting fluorination and ligand-exchange reactions. Previous studies have demonstrated thermal ALE of amorphous HfO2 and ZrO2 ALD films. This study explored the differences between thermal ALE of amorphous and polycrystalline films of hafnium Oxide, Zirconium Oxide, and hafnium Zirconium Oxide on silicon wafers. HF, XeF2, or SF4 were used as the fluorination reactants. Titanium tetrachloride or dimethylaluminum chloride (DMAC) was employed as the metal precursor for ligand exchange. The spectroscopic ellipsometric measurements revealed that the amorphous films had much higher etch rates per cycle than the crystalline films regardless of the fluorination reactants or metal precursors for ligand exchange. The differences were most pronounced for HfO2. Using HF and TiCl4 as the reactants at 250 °C, the etch rates were 0.36 A/cycle for amorphous HfO2 and 0.02 A/cycle for crystalline HfO2. In comparison, the etch rates were 0.61 A/cycle for amorphous ZrO2 and 0.26 A/cycle for crystalline ZrO2. The etch rates were 0.35 A/cycle for amorphous HfZrO4 and 0.04 A/cycle for crystalline HfZrO4. When HF and DMAC were used as the reactants, the etch rates were higher than with HF and TiCl4 for every material. Using HF and DMAC as the reactants at 250 °C, the etch rates were 0.68 A/cycle for amorphous HfO2 and 0.08 A/cycle for crystalline HfO2. In comparison, the etch rates were 1.11 A/cycle for amorphous ZrO2 and 0.82 A/cycle for crystalline ZrO2. The etch rates were 0.69 A/cycle for amorphous HfZrO4 and 0.16 A/cycle for crystalline HfZrO4. SF4 as the fluorination reactant resulted in higher etch rates than for HF when using TiCl4 as the metal precursor for ligand exchange. XeF2 as the fluorination reactant resulted in even higher etch rates than for SF4. The differences in the etch rate with the fluorination reactant can be partially attributed to differences in thermochemistry for fluorination by HF, SF4, and XeF2. The differences in etch rates between amorphous and crystalline films may be caused by the greater degree of fluorination and subsequent ligand-exchange reaction for the amorphous films. The amorphous films have a lower density and may be able to better accommodate the large volume expansion upon fluorination.Thermal atomic layer etching (ALE) can be achieved using sequential, self-limiting fluorination and ligand-exchange reactions. Previous studies have demonstrated thermal ALE of amorphous HfO2 and ZrO2 ALD films. This study explored the differences between thermal ALE of amorphous and polycrystalline films of hafnium Oxide, Zirconium Oxide, and hafnium Zirconium Oxide on silicon wafers. HF, XeF2, or SF4 were used as the fluorination reactants. Titanium tetrachloride or dimethylaluminum chloride (DMAC) was employed as the metal precursor for ligand exchange. The spectroscopic ellipsometric measurements revealed that the amorphous films had much higher etch rates per cycle than the crystalline films regardless of the fluorination reactants or metal precursors for ligand exchange. The differences were most pronounced for HfO2. Using HF and TiCl4 as the reactants at 250 °C, the etch rates were 0.36 A/cycle for amorphous HfO2 and 0.02 A/cycle for crystalline HfO2. In comparison, the etch rates were 0.61 A/cycle...
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Thermal Atomic Layer Etching of Amorphous and Crystalline Hafnium Oxide, Zirconium Oxide, and Hafnium Zirconium Oxide
2019 International Symposium on VLSI Technology Systems and Application (VLSI-TSA), 2019Co-Authors: Jessica A. Murdzek, Steven M. GeorgeAbstract:Thermal atomic layer etching (ALE) using the fluorination and ligand-exchange mechanism was employed to etch amorphous and crystalline films of hafnium Oxide, Zirconium Oxide, and hafnium Zirconium Oxide. HF was the fluorination reactant and dimethylaluminum chloride (DMAC) or titanium tetrachloride was the metal precursor for ligand-exchange. The amorphous films etched faster than the crystalline films. The differences were most pronounced for hafnium Oxide. At 250°C, the etch rate was 0.03-0.08 A/cycle for crystalline HfO 2 and 0.68 A/cycle for amorphous HfO 2 .
H. M. Pathan - One of the best experts on this subject based on the ideXlab platform.
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Zirconium Oxide films: deposition techniques and their applications in dye-sensitized solar cells
Journal of Solid State Electrochemistry, 2017Co-Authors: M. A. Waghmare, Mu. Naushad, Z. A. Alothman, A. U. Ubale, H. M. PathanAbstract:Zirconium Oxide (ZrO_2) is acquiring considerable attention of most of the research groups and leading to a large number of publications due to its unique properties, especially in the context of emerging trends in the third generation of solar cell research. ZrO_2 films offer magnificent aspects related to physicochemical properties, and the properties are found to be dependent on synthesis methods. In the present review, various deposition techniques used to grow Zirconium Oxide thin films and their application to enhance the quantum efficiency of titanium Oxide (TiO_2) based dye-sensitized solar cells (DSSCs) are discussed. Also, the modulated performances of DSSCs fabricated by growing the conformal ZrO_2 insulating films to retard interfacial recombination dynamics on preformed TiO_2 films are discussed. Graphical abstract ᅟ
Nichola J. Coleman - One of the best experts on this subject based on the ideXlab platform.
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The impact of Zirconium Oxide radiopacifier on the early hydration behaviour of white Portland cement.
Materials Science and Engineering: C, 2012Co-Authors: Nichola J. ColemanAbstract:Zirconium Oxide has been identified as a candidate radiopacifying agent for use in Portland cement-based biomaterials. During this study, the impact of 20 wt.% Zirconium Oxide on the hydration and setting reactions of white Portland cement (WPC) was monitored by powder X-ray diffraction (XRD), Si-29 and Al-27 magic angle spinning nuclear magnetic resonance spectroscopy (MAS NMR), transmission electron microscopy (TEM) and Vicat apparatus. The presence of 20 wt.% Zirconium Oxide particles in the size-range of 0.2 to 5 mu m was found to reduce the initial and final setting times of WPC from 172 to 147 min and 213 to 191 min, respectively. Zirconium Oxide did not formally participate in the chemical reactions of the hydrating cement; however, the surface of the Zirconium Oxide particles presented heterogeneous nucleation sites for the precipitation and growth of the early C-S-H gel products which accelerated the initial setting reactions. The presence of Zirconium Oxide was found to have little impact on the development of the calcium (sulpho)aluminate hydrate phases. (C) 2012 Elsevier B.V. All rights reserved.
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The impact of Zirconium Oxide radiopacifier on the early hydration behaviour of white Portland cement.
Materials Science and Engineering: C, 2012Co-Authors: Nichola J. ColemanAbstract:Zirconium Oxide has been identified as a candidate radiopacifying agent for use in Portland cement-based biomaterials. During this study, the impact of 20 wt.% Zirconium Oxide on the hydration and setting reactions of white Portland cement (WPC) was monitored by powder X-ray diffraction (XRD), (29)Si and (27)Al magic angle spinning nuclear magnetic resonance spectroscopy (MAS NMR), transmission electron microscopy (TEM) and Vicat apparatus. The presence of 20 wt.% Zirconium Oxide particles in the size-range of 0.2 to 5 μm was found to reduce the initial and final setting times of WPC from 172 to 147 min and 213 to 191 min, respectively. Zirconium Oxide did not formally participate in the chemical reactions of the hydrating cement; however, the surface of the Zirconium Oxide particles presented heterogeneous nucleation sites for the precipitation and growth of the early C-S-H gel products which accelerated the initial setting reactions. The presence of Zirconium Oxide was found to have little impact on the development of the calcium (sulpho)aluminate hydrate phases.
Francesco Carinci - One of the best experts on this subject based on the ideXlab platform.
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Zirconium Oxide coating improves implant osseointegration in vivo
Dental Materials, 2008Co-Authors: Vincenzo Sollazzo, Carlo Alberto Bignozzi, Leo Massari, Giorgio Brunelli, Furio Pezzetti, Adriano Piattelli, Antonio Scarano, Francesco CarinciAbstract:OBJECTIVES: Zirconium is widely used as material for prosthetic devices because of its good mechanical and chemical properties. When exposed to oxygen, Zirconium becomes Zirconium Oxide (ZO, chemically ZrO(2)) which is biocompatible. ZO can be also prepared as a colloidal suspension and then used to coat surfaces. Zirconium Oxide coating (ZOC) can potentially have specific biologic effects. METHODS: The effect of ZOC on bone throughout an in vivo study using dental implants covered with ZOC and then inserted in rabbit tibia was tested in this study. RESULTS: The histologic analysis demonstrated that (1) bone growth is more evident around ZOC fixtures than in controls and (2) a more mature bone is present in the peri-implant ZOC surface than in controls. SIGNIFICANCE: ZOC can enhance implant osseointegration.
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Zirconium Oxide: analysis of MG63 osteoblast-like cell response by means of a microarray technology.
Biomaterials, 2003Co-Authors: Francesco Carinci, Furio Pezzetti, Stefano Volinia, F. Francioso, Diego Arcelli, E. Farina, Adriano PiattelliAbstract:Zirconium Oxide ceramics have outstanding mechanical properties, a high biocompatibility and a high resistance to scratching. Expression profiling by DNA microarray is a molecular technology that allows the analysis of gene expression in a cell system. By using DNA microarrays containing 19,200 genes, we identified in osteoblast-like cells line (MG-63) cultured on Zirconium Oxide discs (Cercon, Degussa Dental, Hanau, Germany) several genes whose expression was significantly up or down-regulated. The differentially expressed genes cover a broad range of functional activities: (a) immunity, (b) vesicular transport and (c) cell cycle regulation. It was also possible to detect some genes whose function is unknown. The data reported are, to our knowledge, the first genetic portrait of a Zirconium Oxide surface. They can be relevant to better understand the molecular mechanism of biocompatibility and as a model for comparing other materials.
Jessica A. Murdzek - One of the best experts on this subject based on the ideXlab platform.
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Effect of crystallinity on thermal atomic layer etching of hafnium Oxide, Zirconium Oxide, and hafnium Zirconium Oxide
Journal of Vacuum Science and Technology, 2020Co-Authors: Jessica A. Murdzek, Steven M. GeorgeAbstract:Thermal atomic layer etching (ALE) can be achieved using sequential, self-limiting fluorination and ligand-exchange reactions. Previous studies have demonstrated thermal ALE of amorphous HfO2 and ZrO2 ALD films. This study explored the differences between thermal ALE of amorphous and polycrystalline films of hafnium Oxide, Zirconium Oxide, and hafnium Zirconium Oxide on silicon wafers. HF, XeF2, or SF4 were used as the fluorination reactants. Titanium tetrachloride or dimethylaluminum chloride (DMAC) was employed as the metal precursor for ligand exchange. The spectroscopic ellipsometric measurements revealed that the amorphous films had much higher etch rates per cycle than the crystalline films regardless of the fluorination reactants or metal precursors for ligand exchange. The differences were most pronounced for HfO2. Using HF and TiCl4 as the reactants at 250 °C, the etch rates were 0.36 A/cycle for amorphous HfO2 and 0.02 A/cycle for crystalline HfO2. In comparison, the etch rates were 0.61 A/cycle for amorphous ZrO2 and 0.26 A/cycle for crystalline ZrO2. The etch rates were 0.35 A/cycle for amorphous HfZrO4 and 0.04 A/cycle for crystalline HfZrO4. When HF and DMAC were used as the reactants, the etch rates were higher than with HF and TiCl4 for every material. Using HF and DMAC as the reactants at 250 °C, the etch rates were 0.68 A/cycle for amorphous HfO2 and 0.08 A/cycle for crystalline HfO2. In comparison, the etch rates were 1.11 A/cycle for amorphous ZrO2 and 0.82 A/cycle for crystalline ZrO2. The etch rates were 0.69 A/cycle for amorphous HfZrO4 and 0.16 A/cycle for crystalline HfZrO4. SF4 as the fluorination reactant resulted in higher etch rates than for HF when using TiCl4 as the metal precursor for ligand exchange. XeF2 as the fluorination reactant resulted in even higher etch rates than for SF4. The differences in the etch rate with the fluorination reactant can be partially attributed to differences in thermochemistry for fluorination by HF, SF4, and XeF2. The differences in etch rates between amorphous and crystalline films may be caused by the greater degree of fluorination and subsequent ligand-exchange reaction for the amorphous films. The amorphous films have a lower density and may be able to better accommodate the large volume expansion upon fluorination.Thermal atomic layer etching (ALE) can be achieved using sequential, self-limiting fluorination and ligand-exchange reactions. Previous studies have demonstrated thermal ALE of amorphous HfO2 and ZrO2 ALD films. This study explored the differences between thermal ALE of amorphous and polycrystalline films of hafnium Oxide, Zirconium Oxide, and hafnium Zirconium Oxide on silicon wafers. HF, XeF2, or SF4 were used as the fluorination reactants. Titanium tetrachloride or dimethylaluminum chloride (DMAC) was employed as the metal precursor for ligand exchange. The spectroscopic ellipsometric measurements revealed that the amorphous films had much higher etch rates per cycle than the crystalline films regardless of the fluorination reactants or metal precursors for ligand exchange. The differences were most pronounced for HfO2. Using HF and TiCl4 as the reactants at 250 °C, the etch rates were 0.36 A/cycle for amorphous HfO2 and 0.02 A/cycle for crystalline HfO2. In comparison, the etch rates were 0.61 A/cycle...
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Thermal Atomic Layer Etching of Amorphous and Crystalline Hafnium Oxide, Zirconium Oxide, and Hafnium Zirconium Oxide
2019 International Symposium on VLSI Technology Systems and Application (VLSI-TSA), 2019Co-Authors: Jessica A. Murdzek, Steven M. GeorgeAbstract:Thermal atomic layer etching (ALE) using the fluorination and ligand-exchange mechanism was employed to etch amorphous and crystalline films of hafnium Oxide, Zirconium Oxide, and hafnium Zirconium Oxide. HF was the fluorination reactant and dimethylaluminum chloride (DMAC) or titanium tetrachloride was the metal precursor for ligand-exchange. The amorphous films etched faster than the crystalline films. The differences were most pronounced for hafnium Oxide. At 250°C, the etch rate was 0.03-0.08 A/cycle for crystalline HfO 2 and 0.68 A/cycle for amorphous HfO 2 .
