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Research paper thumbnail of Atomic layer deposition of conformal dielectric and protective coatings for released microelectromechanical devices

Research paper thumbnail of Pressure on Thermal Al 2 O 3 Atomic Layer Etch Rates and Al 2 O 3 Fluorination

Thermal Al2O3 atomic layer etching (ALE) can be accomplished using sequential fluorination and li... more Thermal Al2O3 atomic layer etching (ALE) can be accomplished using sequential fluorination and ligand-exchange reactions. HF can be employed as the fluorination reactant, and Al(CH3)3 can be utilized as the metal precursor for ligand exchange. This study explored the effect of HF pressure on the Al2O3 etch rates and Al2O3 fluorination. Different HF pressures ranging from 0.07 to 9.0 Torr were employed for Al2O3 fluorination. Using ex situ spectroscopic ellipsometry (SE) measurements, the Al2O3 etch rates increased with HF pressures and then leveled out at the highest HF pressures. Al2O3 etch rates of 0.6, 1.6, 2.0, 2.4, and 2.5 Å/cycle were obtained at 300 °C for HF pressures of 0.17, 0.5, 1.0, 5.0, and 8.0 Torr, respectively. The thicknesses of the corresponding fluoride layers were also measured using X-ray photoelectron spectroscopy (XPS). Assuming an Al2OF4 layer on the Al2O3 surface, the fluoride thicknesses increased with HF pressures and reached saturation values at the highe...

Research paper thumbnail of Mechanisms of Thermal Atomic Layer Etching

Accounts of Chemical Research

Research paper thumbnail of Atomic Layer Deposition on Particles

ECS Meeting Abstracts

not Available.

Research paper thumbnail of Volatile Etch Species Produced during Thermal Al2O3 Atomic Layer Etching

The Journal of Physical Chemistry C

Research paper thumbnail of Efficient Capacitive Deionization Using Thin Film Sodium Manganese Oxide

Journal of The Electrochemical Society

Research paper thumbnail of Thermal atomic layer etching of crystalline GaN using sequential exposures of XeF2 and BCl3

Research paper thumbnail of Electron-enhanced atomic layer deposition of silicon thin films at room temperature

Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films

Research paper thumbnail of SF4 as the Fluorination Reactant for Al2O3 and VO2 Thermal Atomic Layer Etching

Research paper thumbnail of Spatial atomic layer deposition for coating flexible porous Li-ion battery electrodes

Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films

Research paper thumbnail of Thermal Atomic Layer Etching of Silicon Using O2, HF and Al(CH3)3 as the Reactants

Research paper thumbnail of Oxidation Kinetics of Calcium Films by Water Vapor and Their Effect on Water Vapor Transmission Rate Measurements

The Journal of Physical Chemistry C

Research paper thumbnail of Selectivity in Thermal Atomic Layer Etching Using Sequential, Self-Limiting Fluorination and Ligand-Exchange Reactions

Research paper thumbnail of Atomic Layer Etching of HfO2 Using Sequential, Self-Limiting Thermal Reactions with Sn(acac)2 and HF

ECS Journal of Solid State Science and Technology

Research paper thumbnail of Amorphous Ultrathin TiO2 Atomic Layer Deposition Films on Carbon Nanotubes as Anodes for Lithium Ion Batteries

Journal of the Electrochemical Society

Research paper thumbnail of Atomic Layer Deposition of Metal Fluorides Using HF–Pyridine as the Fluorine Precursor

Research paper thumbnail of SiO2 film growth at low temperatures by catalyzed atomic layer deposition in a viscous flow reactor

Research paper thumbnail of Molecular Layer Deposition for Surface Modification of Lithium-Ion Battery Electrodes

Advanced Materials Interfaces

Research paper thumbnail of WO3 and W Thermal Atomic Layer Etching Using "Conversion-Fluorination" and "Oxidation-Conversion-Fluorination" Mechanisms

ACS applied materials & interfaces, Jan 6, 2017

The thermal atomic layer etching (ALE) of WO3 and W were demonstrated with "conversion-fluor... more The thermal atomic layer etching (ALE) of WO3 and W were demonstrated with "conversion-fluorination" and "oxidation-conversion-fluorination" etching mechanisms. Both of these new mechanisms are based on sequential, self-limiting reactions. WO3 ALE was achieved by a "conversion-fluorination" mechanism using an AB exposure sequence with boron trichloride (BCl3) and hydrogen fluoride (HF). BCl3 converts the WO3 surface to a B2O3 layer while forming volatile WOxCly products. Subsequently, HF spontaneously etches the B2O3 layer producing volatile BF3 and H2O products. In situ spectroscopic ellipsometry (SE) studies determined that the BCl3 and HF reactions were self-limiting versus exposure. The WO3 ALE etch rates increased with temperature from 0.55 Å/cycle at 128°C to 4.19 Å/cycle at 207°C. W served as an etch stop because BCl3 and HF could not etch the underlying W film. W ALE was performed using a three-step "oxidation-conversion-fluorination" ...

Research paper thumbnail of Atomic layer deposition-A novel method for the ultrathin coating of minitablets

International journal of pharmaceutics, Jan 9, 2017

We introduce atomic layer deposition (ALD) as a novel method for the ultrathin coating (nanolayer... more We introduce atomic layer deposition (ALD) as a novel method for the ultrathin coating (nanolayering) of minitablets. The effects of ALD coating on the tablet characteristics and taste masking were investigated and compared with the established coating method. Minitablets containing bitter tasting denatonium benzoate were coated by ALD using three different TiO2 nanolayer thicknesses (number of deposition cycles). The established coating of minitablets was performed in a laboratory-scale fluidized-bed apparatus using four concentration levels of aqueous Eudragit(®) E coating polymer. The coated minitablets were studied with respect to the surface morphology, taste masking capacity, in vitro disintegration and dissolution, mechanical properties, and uniformity of content. The ALD thin coating resulted in minimal increase in the dimensions and weight of minitablets in comparison to original tablet cores. Surprisingly, ALD coating with TiO2 nanolayers decreased the mechanical strength,...

Research paper thumbnail of Atomic layer deposition of conformal dielectric and protective coatings for released microelectromechanical devices

Research paper thumbnail of Pressure on Thermal Al 2 O 3 Atomic Layer Etch Rates and Al 2 O 3 Fluorination

Thermal Al2O3 atomic layer etching (ALE) can be accomplished using sequential fluorination and li... more Thermal Al2O3 atomic layer etching (ALE) can be accomplished using sequential fluorination and ligand-exchange reactions. HF can be employed as the fluorination reactant, and Al(CH3)3 can be utilized as the metal precursor for ligand exchange. This study explored the effect of HF pressure on the Al2O3 etch rates and Al2O3 fluorination. Different HF pressures ranging from 0.07 to 9.0 Torr were employed for Al2O3 fluorination. Using ex situ spectroscopic ellipsometry (SE) measurements, the Al2O3 etch rates increased with HF pressures and then leveled out at the highest HF pressures. Al2O3 etch rates of 0.6, 1.6, 2.0, 2.4, and 2.5 Å/cycle were obtained at 300 °C for HF pressures of 0.17, 0.5, 1.0, 5.0, and 8.0 Torr, respectively. The thicknesses of the corresponding fluoride layers were also measured using X-ray photoelectron spectroscopy (XPS). Assuming an Al2OF4 layer on the Al2O3 surface, the fluoride thicknesses increased with HF pressures and reached saturation values at the highe...

Research paper thumbnail of Mechanisms of Thermal Atomic Layer Etching

Accounts of Chemical Research

Research paper thumbnail of Atomic Layer Deposition on Particles

ECS Meeting Abstracts

not Available.

Research paper thumbnail of Volatile Etch Species Produced during Thermal Al2O3 Atomic Layer Etching

The Journal of Physical Chemistry C

Research paper thumbnail of Efficient Capacitive Deionization Using Thin Film Sodium Manganese Oxide

Journal of The Electrochemical Society

Research paper thumbnail of Thermal atomic layer etching of crystalline GaN using sequential exposures of XeF2 and BCl3

Research paper thumbnail of Electron-enhanced atomic layer deposition of silicon thin films at room temperature

Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films

Research paper thumbnail of SF4 as the Fluorination Reactant for Al2O3 and VO2 Thermal Atomic Layer Etching

Research paper thumbnail of Spatial atomic layer deposition for coating flexible porous Li-ion battery electrodes

Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films

Research paper thumbnail of Thermal Atomic Layer Etching of Silicon Using O2, HF and Al(CH3)3 as the Reactants

Research paper thumbnail of Oxidation Kinetics of Calcium Films by Water Vapor and Their Effect on Water Vapor Transmission Rate Measurements

The Journal of Physical Chemistry C

Research paper thumbnail of Selectivity in Thermal Atomic Layer Etching Using Sequential, Self-Limiting Fluorination and Ligand-Exchange Reactions

Research paper thumbnail of Atomic Layer Etching of HfO2 Using Sequential, Self-Limiting Thermal Reactions with Sn(acac)2 and HF

ECS Journal of Solid State Science and Technology

Research paper thumbnail of Amorphous Ultrathin TiO2 Atomic Layer Deposition Films on Carbon Nanotubes as Anodes for Lithium Ion Batteries

Journal of the Electrochemical Society

Research paper thumbnail of Atomic Layer Deposition of Metal Fluorides Using HF–Pyridine as the Fluorine Precursor

Research paper thumbnail of SiO2 film growth at low temperatures by catalyzed atomic layer deposition in a viscous flow reactor

Research paper thumbnail of Molecular Layer Deposition for Surface Modification of Lithium-Ion Battery Electrodes

Advanced Materials Interfaces

Research paper thumbnail of WO3 and W Thermal Atomic Layer Etching Using "Conversion-Fluorination" and "Oxidation-Conversion-Fluorination" Mechanisms

ACS applied materials & interfaces, Jan 6, 2017

The thermal atomic layer etching (ALE) of WO3 and W were demonstrated with "conversion-fluor... more The thermal atomic layer etching (ALE) of WO3 and W were demonstrated with "conversion-fluorination" and "oxidation-conversion-fluorination" etching mechanisms. Both of these new mechanisms are based on sequential, self-limiting reactions. WO3 ALE was achieved by a "conversion-fluorination" mechanism using an AB exposure sequence with boron trichloride (BCl3) and hydrogen fluoride (HF). BCl3 converts the WO3 surface to a B2O3 layer while forming volatile WOxCly products. Subsequently, HF spontaneously etches the B2O3 layer producing volatile BF3 and H2O products. In situ spectroscopic ellipsometry (SE) studies determined that the BCl3 and HF reactions were self-limiting versus exposure. The WO3 ALE etch rates increased with temperature from 0.55 Å/cycle at 128°C to 4.19 Å/cycle at 207°C. W served as an etch stop because BCl3 and HF could not etch the underlying W film. W ALE was performed using a three-step "oxidation-conversion-fluorination" ...

Research paper thumbnail of Atomic layer deposition-A novel method for the ultrathin coating of minitablets

International journal of pharmaceutics, Jan 9, 2017

We introduce atomic layer deposition (ALD) as a novel method for the ultrathin coating (nanolayer... more We introduce atomic layer deposition (ALD) as a novel method for the ultrathin coating (nanolayering) of minitablets. The effects of ALD coating on the tablet characteristics and taste masking were investigated and compared with the established coating method. Minitablets containing bitter tasting denatonium benzoate were coated by ALD using three different TiO2 nanolayer thicknesses (number of deposition cycles). The established coating of minitablets was performed in a laboratory-scale fluidized-bed apparatus using four concentration levels of aqueous Eudragit(®) E coating polymer. The coated minitablets were studied with respect to the surface morphology, taste masking capacity, in vitro disintegration and dissolution, mechanical properties, and uniformity of content. The ALD thin coating resulted in minimal increase in the dimensions and weight of minitablets in comparison to original tablet cores. Surprisingly, ALD coating with TiO2 nanolayers decreased the mechanical strength,...

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