Sasangan Ramanathan - Academia.edu (original) (raw)
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Papers by Sasangan Ramanathan
ECS Meeting Abstracts, 2005
not Available.
ECS Meeting Abstracts, 2012
not Available.
The Journal of Physical Chemistry, 1995
A series of moderate surface area transition metal carbides and nitrides of molybdenum, tungsten,... more A series of moderate surface area transition metal carbides and nitrides of molybdenum, tungsten, vanadium, niobium, and titanium were prepared by temperature-programmed reaction of the oxide precursor with a reactant gas (20% CHdH2 for the carbides and 100% NH3 for the nitrides). The phase purity and composition of the samples were established by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (X P S) , while surface properties were determined by NZ BET and CO chemisorption measurements. The catalysts were tested in a three-phase trickle-bed reactor for their activity in hydrodenitrogenation (HDN), hydrodesulfurization, and hydrodeoxygenation, with particular emphasis on HDN. The catalytic tests were carried out using a model liquid feed mixture containing 3000 ppm sulfur (dibenzothiophene), 2000 ppm nitrogen (quinoline), 500 ppm oxygen (benzofuran), 20 wt % aromatics (tetralin), and balance aliphatics (tetradecane). The carbides and nitrides were found to be active for HDN of quinoline with activity following the order group 6 > group 5 > group 4. Notably, Mo2C showed superior areal HDN activity than a commercial sulfided Ni-Mo/AlzO3 catalyst (Shell 324). The XRD analysis of the spent catalysts indicated no change in the bulk structure, while XPS results showed little incorporation of sulfur in the surface region of the catalysts, suggesting that these materials are tolerant of sulfur.
ECS Transactions, 2006
We have investigated metal gate electrodes for use with high k HfSiOx gate dielectric films using... more We have investigated metal gate electrodes for use with high k HfSiOx gate dielectric films using AVD® and ALD technology. First, we report on the characterization of the AVD® and ALD deposition techniques where both HfO2 and SiO2 are combined for the formation of HfSiOx. Nitrogen is then incorporated using both in-situ and ex-situ methods to form HfSiON and the resulting film properties are compared. Using an AVD process a work-function of >4.7eV for Ru and RuO2 gate electrode metals in combination with HfSiOx was obtained. A TaN-based metal gate was also characterized to target a promising pMOS solution using different compositions. Together with its high flexibility and composition control, both ALD and AVD® can become key processes for advanced high-k dielectrics as well as compatible CMOS metal electrodes.
2008 9th International Conference on Solid-State and Integrated-Circuit Technology, 2008
Atomic Layer Deposition (ALD) has successfully been applied to advanced microelectronic applicati... more Atomic Layer Deposition (ALD) has successfully been applied to advanced microelectronic applications importantly for conformal coatings on high aspect ratio devices. However, traditional ALD is limited in deposition rate because the ability to bring precursors rapidly to the surface. In this paper we review recent results for precursor delivery using advanced vaporization (Trijet) as well as recent advances in Pulsed CVD (AVD®) using art elements held in common with ALD technology. These and other advances-such as Multiple Single Wafer configurations allow ALD application for continued scaling under conditions of improved process control and higher productivity. Key applications include: capacitors (dielectrics and electrodes), transistors and contacts. This paper reviews these technological advances in the context of their applications.
ECS Transactions, 2007
In this work we discuss the design requirements for achieving higher productivity ALD solutions a... more In this work we discuss the design requirements for achieving higher productivity ALD solutions and we present a single-wafer reactor design that incorporates improvement elements. The effectiveness of this approach is evaluated by examining the improved step coverage, saturation, uniformity and electrical properties of ZrO2 high-k films deposited using this reactor system.
ECS Transactions, 2008
not Available.
PREPRINTS OF PAPERS-AMERICAN …, 1995
... In addition, the transformation of the oxide to the carbidelnitride phase is direct, bypassin... more ... In addition, the transformation of the oxide to the carbidelnitride phase is direct, bypassing themetal phase, which is the most prone to sintering. ... A summary of the synthesis Typically about 0.2-1 g of the catalyst ... p. 147, 1983. 4. Volpe, L., and Boudart, M., J. Solid State Chem. ...
ECS Meeting Abstracts, 2005
not Available.
ECS Meeting Abstracts, 2012
not Available.
The Journal of Physical Chemistry, 1995
A series of moderate surface area transition metal carbides and nitrides of molybdenum, tungsten,... more A series of moderate surface area transition metal carbides and nitrides of molybdenum, tungsten, vanadium, niobium, and titanium were prepared by temperature-programmed reaction of the oxide precursor with a reactant gas (20% CHdH2 for the carbides and 100% NH3 for the nitrides). The phase purity and composition of the samples were established by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (X P S) , while surface properties were determined by NZ BET and CO chemisorption measurements. The catalysts were tested in a three-phase trickle-bed reactor for their activity in hydrodenitrogenation (HDN), hydrodesulfurization, and hydrodeoxygenation, with particular emphasis on HDN. The catalytic tests were carried out using a model liquid feed mixture containing 3000 ppm sulfur (dibenzothiophene), 2000 ppm nitrogen (quinoline), 500 ppm oxygen (benzofuran), 20 wt % aromatics (tetralin), and balance aliphatics (tetradecane). The carbides and nitrides were found to be active for HDN of quinoline with activity following the order group 6 > group 5 > group 4. Notably, Mo2C showed superior areal HDN activity than a commercial sulfided Ni-Mo/AlzO3 catalyst (Shell 324). The XRD analysis of the spent catalysts indicated no change in the bulk structure, while XPS results showed little incorporation of sulfur in the surface region of the catalysts, suggesting that these materials are tolerant of sulfur.
ECS Transactions, 2006
We have investigated metal gate electrodes for use with high k HfSiOx gate dielectric films using... more We have investigated metal gate electrodes for use with high k HfSiOx gate dielectric films using AVD® and ALD technology. First, we report on the characterization of the AVD® and ALD deposition techniques where both HfO2 and SiO2 are combined for the formation of HfSiOx. Nitrogen is then incorporated using both in-situ and ex-situ methods to form HfSiON and the resulting film properties are compared. Using an AVD process a work-function of >4.7eV for Ru and RuO2 gate electrode metals in combination with HfSiOx was obtained. A TaN-based metal gate was also characterized to target a promising pMOS solution using different compositions. Together with its high flexibility and composition control, both ALD and AVD® can become key processes for advanced high-k dielectrics as well as compatible CMOS metal electrodes.
2008 9th International Conference on Solid-State and Integrated-Circuit Technology, 2008
Atomic Layer Deposition (ALD) has successfully been applied to advanced microelectronic applicati... more Atomic Layer Deposition (ALD) has successfully been applied to advanced microelectronic applications importantly for conformal coatings on high aspect ratio devices. However, traditional ALD is limited in deposition rate because the ability to bring precursors rapidly to the surface. In this paper we review recent results for precursor delivery using advanced vaporization (Trijet) as well as recent advances in Pulsed CVD (AVD®) using art elements held in common with ALD technology. These and other advances-such as Multiple Single Wafer configurations allow ALD application for continued scaling under conditions of improved process control and higher productivity. Key applications include: capacitors (dielectrics and electrodes), transistors and contacts. This paper reviews these technological advances in the context of their applications.
ECS Transactions, 2007
In this work we discuss the design requirements for achieving higher productivity ALD solutions a... more In this work we discuss the design requirements for achieving higher productivity ALD solutions and we present a single-wafer reactor design that incorporates improvement elements. The effectiveness of this approach is evaluated by examining the improved step coverage, saturation, uniformity and electrical properties of ZrO2 high-k films deposited using this reactor system.
ECS Transactions, 2008
not Available.
PREPRINTS OF PAPERS-AMERICAN …, 1995
... In addition, the transformation of the oxide to the carbidelnitride phase is direct, bypassin... more ... In addition, the transformation of the oxide to the carbidelnitride phase is direct, bypassing themetal phase, which is the most prone to sintering. ... A summary of the synthesis Typically about 0.2-1 g of the catalyst ... p. 147, 1983. 4. Volpe, L., and Boudart, M., J. Solid State Chem. ...