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Iwao Nishiyama - One of the best experts on this subject based on the ideXlab platform.
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Si(100) etching by Translational Energy controlled atomic chlorine beams
Journal of Applied Physics, 1996Co-Authors: Yuden Teraoka, Iwao NishiyamaAbstract:Si(100) etching was investigated using a Translational Energy controlled atomic chlorine beam. The results were compared with Translational‐Energy‐induced molecular beam etching and conventional gas etching. The etch rate was enhanced by increasing the Translational Energy of the chlorine atoms up to 0.98 eV. The reaction yield of the atomic beam etching was several hundred times greater than that of Translational‐Energy‐induced molecular beam etching. The activation Energy of the atomic beam etching at a 0.28 eV Translational Energy was determined to be 0.76±0.16 eV from an Arrhenius plot. It decreased to 0.62±0.09 eV when the Translational Energy was increased to 0.98 eV. These values were smaller than those for Translational‐Energy‐induced molecular beam etching (1.2±0.3 eV) and conventional gas etching (2.7±0.3 eV).
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Translational-Energy-Induced Anisotropic Etching of Poly-Si by Cl2 Supersonic Molecular Beams
Japanese Journal of Applied Physics, 1994Co-Authors: Yuden Teraoka, Iwao NishiyamaAbstract:A high-Translational-Energy Cl2 neutral beam created in a Cl2-seeded He supersonic molecular beam has been applied to poly-Si etching. Translational-Energy-induced etching was observed at a substrate temperature of 530° C with a Translational Energy threshold of 0.7 eV. From the temperature dependence of the etch rates, the etching reaction was found to be composed of two thermal desorption processes with activation energies of 2.8 eV and 0.9 eV, corresponding to gas etching and Translational-Energy-induced etching, respectively. Anisotropic etching profiles were achieved with complete selectivity against SiO2 due to the fact that the etching was induced by Translational Energy.
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Anisotropic Si(100) etching induced by high Translational Energy Cl2 molecular beams
Applied Physics Letters, 1993Co-Authors: Yuden Teraoka, Iwao NishiyamaAbstract:Si(100) has been etched by high speed Cl2 molecular beams, generated by seeding in He. The Translational Energy dependence for etch rates has been measured by changing the gas mixing ratio and nozzle temperature. The two methods provided the same results. A 2.1 eV Energy threshold was observed at 530 °C substrate temperature. The Cl+/Cl+2 intensity ratio, directly monitored by a quadrupole mass spectrometer, was independent of the nozzle temperature. These facts indicate that the etch rate enhancement is not attributed to Cl radicals or vibrationally excited Cl2 molecules. Owing to the Translational Energy induced etching, anisotropic etching profiles are realized at 670 °C substrate temperature.
A.g. Brenton - One of the best experts on this subject based on the ideXlab platform.
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Calculation of the effect of collisional broadening on high-resolution Translational Energy loss spectra
International Journal of Mass Spectrometry, 2003Co-Authors: A.g. Brenton, Philip JonathanAbstract:Abstract The collisional broadening of peaks in the spectra arising from Translational Energy spectroscopy (TES) studies is theoretically investigated. A numerical calculation, based on the TRIO matrix ion-beam transport computer programme, is used to simulate the collision event and its effects on the focussing properties of a number of ‘double-focussing’ instrument designs. The ion-optical models utilised include a commercial mass spectrometer and two novel high-resolution Energy spectrometers (TESI and TESII), incorporating quadrupole and hexapole field lenses to focus the beam and reduce image aberrations. For a given design of spectrometer, peak broadening is evaluated in terms of the Translational Energy change suffered by the ion during collision and the angle through which it is scattered.
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Translational-Energy spectroscopy: a personal perspective of its development
International Journal of Mass Spectrometry, 2000Co-Authors: A.g. BrentonAbstract:Abstract Translational-Energy spectroscopy (TES) has been widely employed over the last 30 yr to characterize the collision-induced and unimolecular reactions of ions. A personal view is taken of the breath of the field and some of the landmark events that have helped shape it. In this article, the description of the technique is confined to applications for ion beams with Translational energies from 0.1 to 10 keV and those not relying on the absorption or emission of radiation. Collisions of ions with a neutral target gas can reveal spectroscopic information on the states of the participating species, dynamics of the collision, lifetimes of species, collision cross sections, and populations of states. The work from six key laboratories is included to illustrate the range of applications.
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Production of metastable Ar+ ions by electron-impact ionization of Ar measured by Translational-Energy spectroscopy
Physical review. A Atomic molecular and optical physics, 1993Co-Authors: E.y. Kamber, C. S. Enos, A.g. BrentonAbstract:The Translational-Energy-spectroscopy technique has been used to measure the apparent ionization-excitation functions for the metastable states 3 [sup 4]D, 3[ital d] [sup 4]F, 3[ital d] [sup 2]F, and 3[ital d][prime] [sup 2][ital F] of an Ar[sup +] ion beam extracted from an electron-impact ion source. The initial states were identified from the measured Energy loss in the Translational-Energy spectra for single-electron stripping from ground-state and metastable Ar[sup +] ions in collisions with O[sub 2]. This technique provides an alternative method of selectivity in the study of electron-impact ionization and excitation processes.
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Probing vibrational modes in a neutral triatomic molecule by high‐resolution Translational‐Energy spectrometry
Rapid Communications in Mass Spectrometry, 1992Co-Authors: Deepak Mathur, A. C. R. Wilkins, A.g. BrentonAbstract:High-resolution Translational-Energy spectrometry has been applied to study vibrational excitation in neutral CO 2 in its ground electronic state by 3 ke V impact by O + , N + , Ne + , Ar + and Xe + projectile ions. Three quanta of asymmetric stretch mode are excited. Bending mode vibrational excitation also manifests itself in Translational-Energy spectra obtained with the heavier projectile ions (Ne + , Ar + and Xe + ). In the case of the O + projectiles, simultaneous electronic (O +,2 D⇔ 2 P) and vibrational (CO 2 , V 3 =0→ 1) excitation is also observed.
Yuden Teraoka - One of the best experts on this subject based on the ideXlab platform.
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Si(100) etching by Translational Energy controlled atomic chlorine beams
Journal of Applied Physics, 1996Co-Authors: Yuden Teraoka, Iwao NishiyamaAbstract:Si(100) etching was investigated using a Translational Energy controlled atomic chlorine beam. The results were compared with Translational‐Energy‐induced molecular beam etching and conventional gas etching. The etch rate was enhanced by increasing the Translational Energy of the chlorine atoms up to 0.98 eV. The reaction yield of the atomic beam etching was several hundred times greater than that of Translational‐Energy‐induced molecular beam etching. The activation Energy of the atomic beam etching at a 0.28 eV Translational Energy was determined to be 0.76±0.16 eV from an Arrhenius plot. It decreased to 0.62±0.09 eV when the Translational Energy was increased to 0.98 eV. These values were smaller than those for Translational‐Energy‐induced molecular beam etching (1.2±0.3 eV) and conventional gas etching (2.7±0.3 eV).
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Translational-Energy-Induced Anisotropic Etching of Poly-Si by Cl2 Supersonic Molecular Beams
Japanese Journal of Applied Physics, 1994Co-Authors: Yuden Teraoka, Iwao NishiyamaAbstract:A high-Translational-Energy Cl2 neutral beam created in a Cl2-seeded He supersonic molecular beam has been applied to poly-Si etching. Translational-Energy-induced etching was observed at a substrate temperature of 530° C with a Translational Energy threshold of 0.7 eV. From the temperature dependence of the etch rates, the etching reaction was found to be composed of two thermal desorption processes with activation energies of 2.8 eV and 0.9 eV, corresponding to gas etching and Translational-Energy-induced etching, respectively. Anisotropic etching profiles were achieved with complete selectivity against SiO2 due to the fact that the etching was induced by Translational Energy.
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Anisotropic Si(100) etching induced by high Translational Energy Cl2 molecular beams
Applied Physics Letters, 1993Co-Authors: Yuden Teraoka, Iwao NishiyamaAbstract:Si(100) has been etched by high speed Cl2 molecular beams, generated by seeding in He. The Translational Energy dependence for etch rates has been measured by changing the gas mixing ratio and nozzle temperature. The two methods provided the same results. A 2.1 eV Energy threshold was observed at 530 °C substrate temperature. The Cl+/Cl+2 intensity ratio, directly monitored by a quadrupole mass spectrometer, was independent of the nozzle temperature. These facts indicate that the etch rate enhancement is not attributed to Cl radicals or vibrationally excited Cl2 molecules. Owing to the Translational Energy induced etching, anisotropic etching profiles are realized at 670 °C substrate temperature.
Deepak Mathur - One of the best experts on this subject based on the ideXlab platform.
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Measurements of dication lifetimes by Translational Energy spectrometry
Rapid Communications in Mass Spectrometry, 1995Co-Authors: C. P. Safvan, Deepak MathurAbstract:A new application of mass spectrometry to experimental studies of molecular dynamics has been developed and implemented in which ion Translational Energy spectrometry at very high angular resolutions is utilized to study the unimolecular dissociation of metastable dications. A brief overview is presented of the experimental technique, which utilizes a 'home-made', three-sector (equivalent to BEE geometry) instrument. The fragmention kinetic Energy spectrum obtained using such apparatus is capable of yielding information on the lifetimes of specific quantal states of dications of a wide variety of stable and radical species; two illustrative examples (CO 2+ and SH 2+ ) are presented.
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Probing interatomic potentials by ion Translational Energy spectrometry: A new crossed molecular beams apparatus
1992Co-Authors: Deepak Mathur, F. A. Rajgara, Vidhya KrishnamurthiAbstract:This report presents details of the development of a new crossed molecular beams apparatus designed and fabricated to carry out high sensitivity ion Translational Energy spectrometric investigations of the potential Energy surfaces of small molecular species. The Translational Energy spectrometer is used to carry out experimental studies of ion-neutral reactions resulting in charge stripping of CS+ radicals and dissociation of metastable CO2+ dications. These results are interpreted in the light of high-levelab initia molecular orbital calculations of the pertinent molecular potential Energy functions. New results for the double ionisation Energy of CS and the kinetic Energy released upon dissociation of specific electronic states of CO2+ are presented.
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Probing vibrational modes in a neutral triatomic molecule by high‐resolution Translational‐Energy spectrometry
Rapid Communications in Mass Spectrometry, 1992Co-Authors: Deepak Mathur, A. C. R. Wilkins, A.g. BrentonAbstract:High-resolution Translational-Energy spectrometry has been applied to study vibrational excitation in neutral CO 2 in its ground electronic state by 3 ke V impact by O + , N + , Ne + , Ar + and Xe + projectile ions. Three quanta of asymmetric stretch mode are excited. Bending mode vibrational excitation also manifests itself in Translational-Energy spectra obtained with the heavier projectile ions (Ne + , Ar + and Xe + ). In the case of the O + projectiles, simultaneous electronic (O +,2 D⇔ 2 P) and vibrational (CO 2 , V 3 =0→ 1) excitation is also observed.
Anthony Gareth Brenton - One of the best experts on this subject based on the ideXlab platform.
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Translational Energy Spectroscopy
1995Co-Authors: Anthony Gareth BrentonAbstract:The technique of Translational Energy spectroscopy (TES) is described, whereby a collision of a fast ion (a few keV in Energy) with a neutral target gas can reveal spectroscopic information on the states of the participating species. Information on the dynamics of the collision, lifetimes of species, collision cross-sections and populations of states can be revealed. Classi‐cation of collisional processes amenable to TES are given together with simple aspects of relevant collision theory, an appraisal of quantum selection rules for collisions, a description of typical high resolution instrumentation and two simple examples of TES experiments.
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Special feature: Tutorial. Translational Energy spectrocopy
Journal of Mass Spectrometry, 1995Co-Authors: Anthony Gareth BrentonAbstract:The technique of Translational Energy spectroscopy (TES) is described, whereby a collision of a fast ion (a few keV in Energy) with a neutral target gas can reveal spectroscopic information on the states of the participating species. Information on the dynamics of the collision, lifetimes of species, collision cross-sections and populations of states can be revealed. Classification of collisional processes amenable to TES are given together with simple aspects of relevant collision theory, an appraisal of quantum selection rules for collisions, a description of typical high resolution instrumentation and two simple examples of TES experiments.
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Translational Energy spectroscopy studies of metastable populations of N+ ions
AIP Conference Proceedings, 1993Co-Authors: E.y. Kamber, C. S. Enos, Anthony Gareth BrentonAbstract:The Translational Energy technique has been used to study the populations of metastable 1D and 1S states of a N+ ion beam extracted from an electron impact ion source. Variation of the metastable populations was investigated by changing the electron impact Energy (Ee) between 28 and 100 eV. The initial states are identified from the Energy‐loss measured from the Translational Energy spectra for single‐electron stripping processes from 3 keV N+ ions in collisions O2 and He. The instrument employed is a novel double‐focusing Translational spectrometer with high‐Energy resolution sufficient to separate the reaction channels involved.
