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- Whitlow, Harry J, et al.
(författare)
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Measurements of Si ion stopping in amorphous silicon
- 2002
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - 0168-583X. ; 190:1-4, s. 84-88
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Tidskriftsartikel (refereegranskat)abstract
- The stopping of Si-28 ions in polycrystalline Si foils has been measured over the energy range 0.1-3.3 MeV per nucleon. For the low energy interval (0.1-0.5 MeV per nucleon), time of flight-energy elastic recoil detection analysis method was used, whilst for the high energy region (1.2-3.3 MeV per nucleon) the energy loss in the same foil was measured using a Si p-i-n diode with the Si-28 ions directly incident on the foil following acceleration. Below the stopping maximum the results are in good agreement with literature data based on Doppler shift measurements of short nuclear lifetimes but are about 20%, smaller than the SRIM prediction. Above the stopping maximum the data are in agreement with SRIM within the limits of statistical uncertainty.
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2. |
- Timmers, H, et al.
(författare)
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Threshold stoichiometry for beam induced nitrogen depletion of SiN
- 2002
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - 0168-583X. ; 190, s. 428-432
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Tidskriftsartikel (refereegranskat)abstract
- Measurements of the stoichiometry of silicon nitride films as a function of the number of incident ions using heavy ion elastic recoil detection (ERD) show that beam-induced nitrogen depletion depends on the projectile species. the beam energy, and the initial stoichiometry. A threshold stoichiometry exists in the range 1.3 > N/Si greater than or equal to 1, below which the films are stable against nitrogen depletion. Above this threshold, depletion is essentially linear with incident fluence. The depletion rate correlates non-linearly with the electronic energy loss of the projectile ion in the film. Sufficiently long exposure of nitrogen-rich films renders the mechanism, which prevents depletion of nitrogen-poor films, ineffective. Compromising depth-resolution. nitrogen depletion from SiN films during ERD analysis can be reduced significantly by using projectile beams with low atomic numbers. (C) 2002 Published by Elsevier Science B.V.
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3. |
- Winzell, T., et al.
(författare)
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Scanning mu-RBS characterisation of local loading effects of non-selectively epitaxially grown SiGe thin films
- 2001
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Ingår i: Nuclear Instruments and Methods in Physics Research Section B. - 0168-583X .- 1872-9584. ; 179:1, s. 121-125
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Tidskriftsartikel (refereegranskat)abstract
- Scanning microbeam Rutherford backscattering spectrometry (mu -RBS) has been employed to investigate local loading effects of non-selective epitaxial growth (NSEG) of SiGe on Si in structures consisting of apertures in an SiO2 mask. The structure sizes were 22 mum x 22 mum. 42 mum x 42 mum, 82 mum x 82 mum and 500 mum x 2000 mum. From the measured thickness and Ge content, it was concluded that in NSEG local loading effects for the structure sizes used are small or absent.
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5. |
- Persson, L., et al.
(författare)
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Separation of mass-overlapped time of flight-energy elastic recoil detection analysis data using Ryan and Jamieson's dynamic analysis method
- 2001
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Ingår i: Nuclear Instruments and Methods in Physics Research Section B. - 0168-583X .- 1872-9584. ; 179:3, s. 403-411
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Tidskriftsartikel (refereegranskat)abstract
- Time of flight-energy (ToF-E) elastic recoil detection analysis (ERDA) data often contains mass signals with considerable overlap from adjacent isotopes in the mass-energy plane. An evaluation has been carried out of the suitability of the dynamic analysis method proposed by Ryan and Jamieson to decompose elemental signals with overlapping mass. This method is shown to work very well on generated test data and the result when it was applied to experimental data appears quite promising. Very accurate mass calibration and lineshape determination was found to be a prerequisite for the application of the method.
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6. |
- Timmers, H, et al.
(författare)
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Energy loss measurements for mass-14 ions using a patterned stopping medium on a PIN diode
- 2004
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 219-20, s. 263-267
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Tidskriftsartikel (refereegranskat)abstract
- A new experimental technique to measure stopping forces for swift heavy ions was tested and has been found effective. A commercial PIN photodiode was coated with a patterned stopping medium of gold. This allowed the simultaneous detection of stopped- and reference-ions of C-14 and N-14 in the energy range E = 6.4-10.4 MeV. The stopping forces of these ions in gold have been measured with excellent accuracy. They are up to 10% larger than expected from present tabulations. It would be straightforward to use the same modified PIN diode in other experiments providing direct comparisons for an identical stopping medium.
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7. |
- Whitlow, Harry J, et al.
(författare)
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Measurement and uncertainties of energy loss in silicon over a wide Z(1) range using time of flight detector telescopes
- 2002
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - 0168-583X. ; 195:1-2, s. 133-146
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Tidskriftsartikel (refereegranskat)abstract
- The energy loss of projectiles with Z(1) in the range 3-26 has been experimentally measured in the 0.1-0.7 MeV per nucleon energy range in the same Si stopping foil of 105.5 mug cm(-2) thickness using a time of flight-energy (ToF-E) elastic recoil detection analysis (ERDA) setup. A detailed study of the experimental uncertainties for ToF-E and ToF-ToF-E configuration has been made. For ERDA configurations where the energy calibration is taken against the edge positions small uncertainties in the angle at which recoils are detected can introduce significant, absolute uncertainty. The relative uncertainty contribution is dominated by the energy calibration of the Si E detector for the ToF-E configuration and the position of the second ToF detector in ToF-ToF-E measurements. The much smaller calibration uncertainty for ToF-ToF-E configuration implies this technique is superior to ToF-E measurements with Si E detectors. At low energies the effect of charge changing in the time detector foils can become important. It was found that empirical stopping numbers which include the effect of effective-charge were more closely clustered about a trend line when plotted against the Bohr parameter than the corresponding Bethe parameter. Study of the deviations from the trend line showed evidence of a shell dependant effect that exceeded the anticipated maximum relative uncertainties.
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