Monte-Carlo simulations of ion track in silicon and influence of its spatial distribution on single event effects
ABSTRACT High energy interaction of heavy ions with silicon integrated circuits contribute to transient events or single event effects (SEE) when ionizing the device along the particle path. Knowledge of the electron–hole pair density in the ion track is necessary for studying collected charge and estimating device reliability for deep sub-micron transistors. We have simulated ion-tracks in silicon with a Monte-Carlo code, TRAMOS, which is reported in this paper. High velocity heavy ion interactions with silicon are described within the plane wave Born approximation. For electrons, differential cross-sections are calculated using the phase shift method for elastic collisions and the BEB model for inelastic interactions. Calculations show that for high ion velocities, a non-negligible fraction of the energy is deposited outside the sensitive volume of sub-micron transistors when compared to the case of the low ion velocities. The response of a silicon on insulator transistor to different ion tracks (size, density) is investigated with device simulations. Results show that for the 0.25 μm gate length transistor simulated, due to the technology used, the size of the ion track has minor effect on the collected charge Qc. For ions with same stopping power and different velocities, differences on Qc may show up, due to recombination mechanisms.
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ABSTRACT: Two models for the calculation of ionization cross sections by electron impact on atoms, the Binary-Encouter-Bethe and the Deutsch-Maerk models, have been implemented; they are intended to extend and improve Geant4 simulation capabilities in the energy range below 1 keV. The physics features of the implementation of the models are described, and their differences with respect to the original formulations are discussed. Results of the verification with respect to the original theoretical sources and of extensive validation with respect to experimental data are reported. The validation process also concerns the ionization cross sections included in the Evaluated Electron Data Library used by Geant4 for low energy electron transport. Among the three cross section options, the Deutsch-Maerk model is identified as the most accurate at reproducing experimental data over the energy range subject to test.10/2011;
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ABSTRACT: Differential spatiotemporal distributions of the deposited energy around ion tracks in SiO<sub>2</sub> are calculated using Monte Carlo simulations with input parameters extracted from the complex dielectric function theory. It is shown that the spatial and temporal dependences cannot be separated. The track evolution and the time to reach a given energy deposition are approximately calculated. The track radius is evaluated from the radial distribution of the deposited energy as a function of ion energy. Formation of a visible track due to lattice damage through ionization (latent track), as well as straggling in energy deposition are discussed.IEEE Transactions on Nuclear Science 09/2008; · 1.45 Impact Factor