scholarly journals Classical scattering and stopping power in dense plasmas: the effect of diffraction and dynamic screening

2016 ◽  
Vol 34 (3) ◽  
pp. 457-466 ◽  
Author(s):  
M. K. Issanova ◽  
S. K. Kodanova ◽  
T. S. Ramazanov ◽  
N. Kh. Bastykova ◽  
Zh. A. Moldabekov ◽  
...  

AbstractIn the present work, classical electron–ion scattering, Coulomb logarithm, and stopping power are studied taking into account the quantum mechanical diffraction effect and the dynamic screening effect separately and together. The inclusion of the quantum diffraction effect is realized at the same level as the well-known first-order gradient correction in the extended Thomas–Fermi theory. In order to take the effect of dynamic screening into account, the model suggested by Grabowski et al. in 2013 is used. Scattering as well as stopping power of the external electron (ion) beam by plasma ions (electrons) and scattering of the plasma's own electrons (ions) by plasma ions (electrons) are considered differently. In the first case, it is found that in the limit of the non-ideal plasma with a plasma parameter Γ → 1, the effects of quantum diffraction and dynamic screening partially compensate each other. In the second case, the dynamic screening enlarges scattering cross-section, Coulomb logarithm, and stopping power, whereas the quantum diffraction reduces their values. Comparisons with the results of other theoretical methods and computer simulations indicate that the model used in this work gives a good description of the stopping power for projectile velocities $v\,{\rm \lesssim}\, 1.5 v_{{\rm th}}$, where vth is the thermal velocity of the plasma electrons.

Author(s):  
Z. G. Song ◽  
S. K. Loh ◽  
X. H. Zheng ◽  
S.P. Neo ◽  
C. K. Oh

Abstract This article presents two cases to demonstrate the application of focused ion beam (FIB) circuit edit in analysis of memory failure of silicon on insulator (SOI) devices using XTEM and EDX analyses. The first case was a single bit failure of SRAM units manufactured with 90 nm technology in SOI wafer. The second case was the whole column failure with a single bit pass for a SRAM unit. From the results, it was concluded that FIB circuit edit and electrical characterization is a good methodology for further narrowing down the defective location of memory failure, especially for SOI technology, where contact-level passive voltage contrast is not suitable.


Author(s):  
Dirk Doyle ◽  
Lawrence Benedict ◽  
Fritz Christian Awitan

Abstract Novel techniques to expose substrate-level defects are presented in this paper. New techniques such as inter-layer dielectric (ILD) thinning, high keV imaging, and XeF2 poly etch overflow are introduced. We describe these techniques as applied to two different defects types at FEOL. In the first case, by using ILD thinning and high keV imaging, coupled with focused ion beam (FIB) cross section and scanning transmission electron microscopy (STEM,) we were able to judge where to sample for TEM from a top down perspective while simultaneously providing the top down images giving both perspectives on the same sample. In the second case we show retention of the poly Si short after removal of CoSi2 formation on poly. Removal of the CoSi2 exposes the poly Si such that we can utilize XeF2 to remove poly without damaging gate oxide to reveal pinhole defects in the gate oxide. Overall, using these techniques have led to 1) increased chances of successfully finding the defects, 2) better characterization of the defects by having a planar view perspective and 3) reduced time in localizing defects compared to performing cross section alone.


1995 ◽  
Vol 396 ◽  
Author(s):  
A. L. Evelyn ◽  
D. Ila ◽  
J. Fisher ◽  
D. B. Poker

AbstractThe electronic and nuclear stopping effects produced by MeV ion bombardment in polyvinylidine chloride (PVDC) and polyethylene (PE) are separated by stacking thin films of the polymers. The resulting multi-layer laminates of each polymer were bombarded with 3.5 MeV alpha particles. The energy of the incident ions was selected, using TRIM, such that the first layers experienced most of the effects of the electronic energy deposited and the last layers received most of the effects of the nuclear stopping power. The changes in the conductance and the chemical structure of each layer were measured by direct resistivity measurements and Raman microprobe analysis.


2011 ◽  
Vol 38 (6Part29) ◽  
pp. 3768-3769
Author(s):  
D Sanchez-Parcerisa ◽  
A Gemmel ◽  
K Parodi ◽  
O Jäkel ◽  
E Rietzel

2011 ◽  
Vol 29 (3) ◽  
pp. 299-304 ◽  
Author(s):  
Zhang-Hu Hu ◽  
Yuan-Hong Song ◽  
Z.L. Mišković ◽  
You-Nian Wang

AbstractWe use a two-dimensional particle-in-cell simulation to investigate the dynamic polarization and stopping power for an ion beam propagating through a two-component plasma, which is simultaneously irradiated by a strong laser pulse. Compared to the laser-free case, we observe a reduction in the instantaneous stopping power that initially follows the shape of the laser pulse and becomes particularly large as the laser frequency approaches the plasma electron frequency. We attribute this large reduction in the ion stopping power to an increase in plasma temperature due to the energy absorbed in the plasma from the laser pulse through the process of wave heating. In addition, dynamic polarization of the plasma by the ion is found to be strongly modulated by the laser field.


1996 ◽  
Vol 53 (22) ◽  
pp. 14773-14781 ◽  
Author(s):  
M. Beranger ◽  
P. Thevenard ◽  
R. Brenier ◽  
B. Canut ◽  
S. M. M. Ramos ◽  
...  

2009 ◽  
Author(s):  
Emanuele Scifoni ◽  
Eugene Surdutovich ◽  
Andrey V. Solov’yov ◽  
Andrey Solov́yov ◽  
Eugene Surdutovich

1978 ◽  
Vol 20 (3) ◽  
pp. 351-364 ◽  
Author(s):  
J. P. Hauck ◽  
Gregory Benford

We inject a fast ion beam across a magnetic field, through a cylindrical 5 cm diameter plasma. Shear Kelvin–Helmholtz waves, already present in the plasma, are considerably amplified. The ion beam is rapidly slowed and scattered. The observed stopping power exceeds the classical power by over two orders of magnitude. A simple theoretical estimate, ascribing beam energy loss to driving of the waves, agrees qualitatively with observations.


2021 ◽  
Author(s):  
Sophia Malko ◽  
Witold Cayzac ◽  
Valeria Ospina-Bohorquez ◽  
Krish Bhutwala ◽  
M Bailly-Grandvaux ◽  
...  

Abstract Ion stopping in warm dense matter is a process of fundamental importance for the understanding of the properties of dense plasmas, the realization and the interpretation of experiments involving ion-beam-heated warm dense matter samples, and for inertial confinement fusion research. The theoretical description of the ion stopping power in warm dense matter is difficult notably due to electron coupling and degeneracy, and measurements are still largely missing. In particular, the low-velocity stopping range around the Bragg peak, that features the largest modeling uncertainties, remains virtually unexplored. Here, we report proton energy-loss measurements in warm dense plasma at unprecedented low projectile velocities, approaching significantly the Bragg-peak region. Our energy-loss data, combined with a precise target characterization based on plasma emission measurements using two independent spectroscopy diagnostics, demonstrate a significant deviation of the stopping power from classical models in this regime. In particular, we show that our results are consistent with recent first-principles simulations based on time-dependent density functional theory.


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