The Experts below are selected from a list of 228 Experts worldwide ranked by ideXlab platform

Nader Sadeghi - One of the best experts on this subject based on the ideXlab platform.

  • Vacuum ultraviolet-absorption spectroscopy and delocalized plasma-induced emission used for the species detection in a down-stream soft-etch plasma reactor
    Journal of Vacuum Science and Technology A, 2020
    Co-Authors: Robert Soriano, Gilles Cunge, Nader Sadeghi
    Abstract:

    The VUV-absorption spectroscopy (AS) and the emission spectroscopy (ES) from delocalized probe plasma, are implemented in the downstream chamber of a soft-etch industrial plasma reactor. A CCP plasma, running in the upper compartment in He/NF3/NH3/H2 mixtures at about one Torr, produces reactive species which flow through a shower head into a downstream chamber, where they can etch different µ-electronics materials: Si, SiO2, SiN,... The ES reveals the presence of F and H atoms, while the dissociation rates of NF3 and NH3 are deduced from the AS, as well as the density of HF molecules, produced by Chemical Chain-reactions between dissociation products of NF3, NH3 and H2.

  • Vacuum ultraviolet-absorption spectroscopy and delocalized plasma-induced emission used for the species detection in a down-stream soft-etch plasma reactor
    Journal of Vacuum Science & Technology A, 2020
    Co-Authors: Robert Soriano, Gilles Cunge, Nader Sadeghi
    Abstract:

    Vacuum ultraviolet-absorption spectroscopy (AS) and emission spectroscopy (ES) from delocalized probe plasma are implemented in the downstream chamber of a soft-etch industrial plasma reactor. A capacitively coupled plasma plasma, running in the upper compartment in He/NF3/NH3/H2 mixtures at about 1 Torr, produces reactive species which flow through a shower head into a downstream chamber, where they can etch different μ-electronic materials: Si, SiO2, SiN, etc. The ES reveals the presence of F atoms, while the dissociation rates of NF3 and NH3 are deduced from the AS, as well as the density of HF molecules, produced by Chemical Chain-reactions between dissociation products of NF3, NH3, and H2. The variations of HF density as a function of the NH3 flow rate suggest the possible formation of NH4F molecules in the plasma.

Robert Soriano - One of the best experts on this subject based on the ideXlab platform.

  • Vacuum ultraviolet-absorption spectroscopy and delocalized plasma-induced emission used for the species detection in a down-stream soft-etch plasma reactor
    Journal of Vacuum Science and Technology A, 2020
    Co-Authors: Robert Soriano, Gilles Cunge, Nader Sadeghi
    Abstract:

    The VUV-absorption spectroscopy (AS) and the emission spectroscopy (ES) from delocalized probe plasma, are implemented in the downstream chamber of a soft-etch industrial plasma reactor. A CCP plasma, running in the upper compartment in He/NF3/NH3/H2 mixtures at about one Torr, produces reactive species which flow through a shower head into a downstream chamber, where they can etch different µ-electronics materials: Si, SiO2, SiN,... The ES reveals the presence of F and H atoms, while the dissociation rates of NF3 and NH3 are deduced from the AS, as well as the density of HF molecules, produced by Chemical Chain-reactions between dissociation products of NF3, NH3 and H2.

  • Vacuum ultraviolet-absorption spectroscopy and delocalized plasma-induced emission used for the species detection in a down-stream soft-etch plasma reactor
    Journal of Vacuum Science & Technology A, 2020
    Co-Authors: Robert Soriano, Gilles Cunge, Nader Sadeghi
    Abstract:

    Vacuum ultraviolet-absorption spectroscopy (AS) and emission spectroscopy (ES) from delocalized probe plasma are implemented in the downstream chamber of a soft-etch industrial plasma reactor. A capacitively coupled plasma plasma, running in the upper compartment in He/NF3/NH3/H2 mixtures at about 1 Torr, produces reactive species which flow through a shower head into a downstream chamber, where they can etch different μ-electronic materials: Si, SiO2, SiN, etc. The ES reveals the presence of F atoms, while the dissociation rates of NF3 and NH3 are deduced from the AS, as well as the density of HF molecules, produced by Chemical Chain-reactions between dissociation products of NF3, NH3, and H2. The variations of HF density as a function of the NH3 flow rate suggest the possible formation of NH4F molecules in the plasma.

Gilles Cunge - One of the best experts on this subject based on the ideXlab platform.

  • Vacuum ultraviolet-absorption spectroscopy and delocalized plasma-induced emission used for the species detection in a down-stream soft-etch plasma reactor
    Journal of Vacuum Science and Technology A, 2020
    Co-Authors: Robert Soriano, Gilles Cunge, Nader Sadeghi
    Abstract:

    The VUV-absorption spectroscopy (AS) and the emission spectroscopy (ES) from delocalized probe plasma, are implemented in the downstream chamber of a soft-etch industrial plasma reactor. A CCP plasma, running in the upper compartment in He/NF3/NH3/H2 mixtures at about one Torr, produces reactive species which flow through a shower head into a downstream chamber, where they can etch different µ-electronics materials: Si, SiO2, SiN,... The ES reveals the presence of F and H atoms, while the dissociation rates of NF3 and NH3 are deduced from the AS, as well as the density of HF molecules, produced by Chemical Chain-reactions between dissociation products of NF3, NH3 and H2.

  • Vacuum ultraviolet-absorption spectroscopy and delocalized plasma-induced emission used for the species detection in a down-stream soft-etch plasma reactor
    Journal of Vacuum Science & Technology A, 2020
    Co-Authors: Robert Soriano, Gilles Cunge, Nader Sadeghi
    Abstract:

    Vacuum ultraviolet-absorption spectroscopy (AS) and emission spectroscopy (ES) from delocalized probe plasma are implemented in the downstream chamber of a soft-etch industrial plasma reactor. A capacitively coupled plasma plasma, running in the upper compartment in He/NF3/NH3/H2 mixtures at about 1 Torr, produces reactive species which flow through a shower head into a downstream chamber, where they can etch different μ-electronic materials: Si, SiO2, SiN, etc. The ES reveals the presence of F atoms, while the dissociation rates of NF3 and NH3 are deduced from the AS, as well as the density of HF molecules, produced by Chemical Chain-reactions between dissociation products of NF3, NH3, and H2. The variations of HF density as a function of the NH3 flow rate suggest the possible formation of NH4F molecules in the plasma.

David J. Nesbitt - One of the best experts on this subject based on the ideXlab platform.

  • State-to-State Thermal/Hyperthermal Collision Dynamics of Atmospheric Species
    2003
    Co-Authors: David J. Nesbitt
    Abstract:

    Abstract : Shot-noise limited, direct absorption IR laser methods have been used to study (i) state-to-state reaction dynamics in crossed supersonic jets and (ii) temperature dependent studies of OH + O3 Chemical Chain reaction kinetics via flash kinetic spectroscopy. In this first area. state-resolved studies of F + H2 scattering have been completed from E =2.4 kcals/mole down to 0.30 kcals/mole, which by virtue of the high quantum state resolution in product detection have revealed contributions due to non-adiabatic reactions with spin orbit excited F4 atoms. These methods have been extended to F + CH4, where high resolution IR laser Dopplerimetry can be used to extract product state velocities and thus differential cross section information at the state-to- state level. Time-resolved flash kinetic studies of the OH/HO2/O3 Chemical Chain reaction has been performed from 300K down to 180 K. providing first access to temperature conditions relevant to accurate modeling of the lower stratosphere. These methods have been extended to study "airglow" dynamics of highly rotationally excited OH(v1N) radicals formed from H + O3 reactions.

  • Thermal Hyperthermal Collision Dynamics of Atmospheric Species
    2000
    Co-Authors: David J. Nesbitt, Warren W. Harper, Sergey A. Nizkorodov, Bill Chapman, Brad Blackman
    Abstract:

    Abstract : Shot-noise limited, direct absorption IR laser methods have been used to study (i) state-to-state reaction dynamics in crossed supersonic jets and (ii) temperature dependent studies of OH + O(3) Chemical Chain reaction kinetics via flash kinetic spectroscopy. In this first area. state-resolved studies of F + H(2) scattering have been completed from E = 2.4 kcal/mole down to 0.30 kcals/mole, which by virtue of the high quantum state resolution in product detection have revealed contributions due to non-adiabotic reactions with spin orbit excited F atoms. These methods have been extended to F + CH(4), where high resolution IR laser Dopplerimetry can be used to extract product state velocities and thus differential cross section information at the state-to-stale level. Time-resolved flash kinetic studies of the OH/HO(2)/O(3) Chemical Chain reaction has been performed from 300 K down 0 190 K. providing first access to temperature conditions relevant to accurate modeling of the lower stratosphere. These methods have been extended to study "airglow' dynamics of highly rotationally excited OH(v.N) radicals formed from H + O(3) reactions.

  • Time-Resolved O3 Chemical Chain Reaction Kinetics via High-Resolution IR Laser Absorption Methods
    The Journal of Physical Chemistry A, 1998
    Co-Authors: Axel Kulcke, Brad W. Blackmon, William B. Chapman, In Koo Kim, David J. Nesbitt
    Abstract:

    Excimer laser photolysis in combination with time-resolved IR laser absorption detection of OH radicals has been used to study O3/OH(v = 0)/HO2 Chain reaction kinetics at 298 K, (i.e.,(k(sub 1) is OH + 03 yields H02 + 02 and (k(sub 2) is H02 + 03 yields OH + 202). From time-resolved detection of OH radicals with high-resolution near IR laser absorption methods, the Chain induction kinetics have been measured at up to an order of magnitude higher ozone concentrations ([03] less than or equal to 10(exp 17) molecules/cu cm) than accessible in previous studies. This greater dynamic range permits the full evolution of the Chain induction, propagation, and termination process to be temporally isolated and measured in real time. An exact solution for time-dependent OH evolution under pseudo- first-order Chain reaction conditions is presented, which correctly predicts new kinetic signatures not included in previous OH + 03 kinetic analyses. Specifically, the solutions predict an initial exponential loss (Chain "induction") of the OH radical to a steady-state level ([OH](sub ss)), with this fast initial decay determined by the sum of both Chain rate constants, k(sub ind) = k(sub 1) + k(sub 2). By monitoring the Chain induction feature, this sum of the rate constants is determined to be k(sub ind) = 8.4(8) x 10(exp -14) cu cm/molecule/s for room temperature reagents. This is significantly higher than the values currently recommended for use in atmospheric models, but in excellent agreement with previous results from Ravishankara et al.

Michelle D. Klingshirn - One of the best experts on this subject based on the ideXlab platform.