Abstract
Mass and energy dispersive Recoil Spectrometry (RS) using heavy ions at energies of about 0.2{Alpha}-0.8{Alpha} MeV has attracted much interest recently due to its potential for separately and unambiguously generating information on isotopic depth distributions. The principal advantages of mass and energy dispersive RS are that both light and heavy elements can be separately studied simultaneously and problems caused by chemical matrix effects are avoided since the technique is based on high energy nucleus-nucleus scattering. In order to elucidate reactions taking place in various GaAs structures, Time of flight-Energy (ToF-E) RS was developed to allow Ga and As to be studied separately down to depths of about 500-800 nm with a depth resolution of about 16 nm at the surface. This was shown in a study of an Al{sub x}Ga{sub 1-x}As quantum-well structure. The benefits of using ToF-E RS on GaAs structures were further demonstrated in studies of Co/GaAs and CoSi{sub 2}/GaAs reactions, as well as in a study of the composition of MOCVD grown Al{sub x}Ga{sub 1-x}As. Most recoil measurements employed {sup 127}I at energies of about 50-90 MeV as projectiles. The recoil detector telescope consisted of a silicon energy detector and two carbon foil time pick-off detectors separated
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Citation Formats
Hult, M.
Mass and energy dispersive recoil spectrometry of GaAs structures.
Sweden: N. p.,
1994.
Web.
Hult, M.
Mass and energy dispersive recoil spectrometry of GaAs structures.
Sweden.
Hult, M.
1994.
"Mass and energy dispersive recoil spectrometry of GaAs structures."
Sweden.
@misc{etde_10103928,
title = {Mass and energy dispersive recoil spectrometry of GaAs structures}
author = {Hult, M}
abstractNote = {Mass and energy dispersive Recoil Spectrometry (RS) using heavy ions at energies of about 0.2{Alpha}-0.8{Alpha} MeV has attracted much interest recently due to its potential for separately and unambiguously generating information on isotopic depth distributions. The principal advantages of mass and energy dispersive RS are that both light and heavy elements can be separately studied simultaneously and problems caused by chemical matrix effects are avoided since the technique is based on high energy nucleus-nucleus scattering. In order to elucidate reactions taking place in various GaAs structures, Time of flight-Energy (ToF-E) RS was developed to allow Ga and As to be studied separately down to depths of about 500-800 nm with a depth resolution of about 16 nm at the surface. This was shown in a study of an Al{sub x}Ga{sub 1-x}As quantum-well structure. The benefits of using ToF-E RS on GaAs structures were further demonstrated in studies of Co/GaAs and CoSi{sub 2}/GaAs reactions, as well as in a study of the composition of MOCVD grown Al{sub x}Ga{sub 1-x}As. Most recoil measurements employed {sup 127}I at energies of about 50-90 MeV as projectiles. The recoil detector telescope consisted of a silicon energy detector and two carbon foil time pick-off detectors separated by a variable flight length of 213.5-961 mm. The reactions taking place between various thin films and GaAs were also studied using complementary techniques such as XRD, XPS and SEM. Co was found to react extensively with GaAs, already at about 300 degrees C, making it unsuitable as a contact material. Thin films of Co and Si were found to react extensively with each other and to form CoSi{sub 2} at 500 degrees C and above. CoSi{sub 2}, a low resistivity silicide, turned out to be stable on GaAs, at least up to 700 degrees C. Considerable grain growth could cause problems, however, in the use of CoSi{sub 2}-contacts. 112 refs, figs, tabs.}
place = {Sweden}
year = {1994}
month = {Aug}
}
title = {Mass and energy dispersive recoil spectrometry of GaAs structures}
author = {Hult, M}
abstractNote = {Mass and energy dispersive Recoil Spectrometry (RS) using heavy ions at energies of about 0.2{Alpha}-0.8{Alpha} MeV has attracted much interest recently due to its potential for separately and unambiguously generating information on isotopic depth distributions. The principal advantages of mass and energy dispersive RS are that both light and heavy elements can be separately studied simultaneously and problems caused by chemical matrix effects are avoided since the technique is based on high energy nucleus-nucleus scattering. In order to elucidate reactions taking place in various GaAs structures, Time of flight-Energy (ToF-E) RS was developed to allow Ga and As to be studied separately down to depths of about 500-800 nm with a depth resolution of about 16 nm at the surface. This was shown in a study of an Al{sub x}Ga{sub 1-x}As quantum-well structure. The benefits of using ToF-E RS on GaAs structures were further demonstrated in studies of Co/GaAs and CoSi{sub 2}/GaAs reactions, as well as in a study of the composition of MOCVD grown Al{sub x}Ga{sub 1-x}As. Most recoil measurements employed {sup 127}I at energies of about 50-90 MeV as projectiles. The recoil detector telescope consisted of a silicon energy detector and two carbon foil time pick-off detectors separated by a variable flight length of 213.5-961 mm. The reactions taking place between various thin films and GaAs were also studied using complementary techniques such as XRD, XPS and SEM. Co was found to react extensively with GaAs, already at about 300 degrees C, making it unsuitable as a contact material. Thin films of Co and Si were found to react extensively with each other and to form CoSi{sub 2} at 500 degrees C and above. CoSi{sub 2}, a low resistivity silicide, turned out to be stable on GaAs, at least up to 700 degrees C. Considerable grain growth could cause problems, however, in the use of CoSi{sub 2}-contacts. 112 refs, figs, tabs.}
place = {Sweden}
year = {1994}
month = {Aug}
}