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This correspondence comments on the correlation between measured and simulated charge collection in two diode structures presented in [1]. In [1], results from pulsed-laser-induced charge deposition via two-photon absorption revealed reasonable correlation between experimental data and simulations in some aspects but showed lack of correlation in terms of the measured and predicted magnitudes of the collected charge. The source of this poor agreement has recently been determined, and is attributed to an incorrect pulse energy calibration used for those experiments. With the proper energy calibration applied, the agreement between simulation and experiment is nearly quantitative for all observables in both devices. These results significantly strengthen the validity of the nonlinear optical beam propagation method numerical approach for accurately predicting pulsed-laser-induced charge deposition. [ABSTRACT FROM PUBLISHER]

Carrier-density distributions generated via two-photon absorption from pulsed laser excitation are simulated using nonlinear-optical beam propagation software. These simulated carrier-density distributions are used to calculate depth profiles of the integrated collected charge using a rectangular-parallel-piped approach for two silicon diodes of different structure. Using a set of proposed correlation metrics, the resulting simulated charge collection profiles are found to exhibit good agreement with measured transient charge-collection data for most, but not all of the metrics. The physical phenomena underlying the correlation metrics are discussed in detail. The remaining discrepancies that exist between the simulated and experimental results are addressed and their potential causes are detailed. [ABSTRACT FROM PUBLISHER]

Variability in energy deposition caused by intrinsic statistical fluctuations is quantified for specific radiation environments. Differences in effective flux are observed for minimally ionizing particles, typically leading to a decrease in predicted soft error rate, the magnitude of which depends on the threshold LET. When compared to spectra accounting for energy-deposition fluctuations, predictions with traditional LET spectra in CREME96 are found to lead to conservative estimates in almost all situations. [ABSTRACT FROM AUTHOR]

Heavy-ion and two-photon-absorption (TPA) experiments have been performed on ultra-thin implant-free quantum well SiGe channel pMOSFETs. Both the single-event-transient pulse magnitude and polarity can depend strongly on the location of the strike along the device channel. The polarity inversion occurs primarily because very limited transient charge collection occurs below the quantum well, as confirmed by two-dimensional TCAD simulation. [ABSTRACT FROM PUBLISHER]

Transient capture measurements on an irradiated diode show the effect of increasing ion LET and varying strike location on transient current response. Significant modulation of the electrostatic potential in the device depletion region during and after the strike profoundly affects transient characteristics. The peak transient current tends to saturate with increasing ionization intensity. The saturation depends on device parameters and the applied bias. A previously developed analytical model is used to describe the mechanisms responsible for this trend. Ion strikes near the device contacts produce transients that are significantly different than strikes away from the contacts, but still in the active region of the device. This is attributed to well potential modulation effects. Device-level simulations, broadbeam heavy-ion measurements, and two-photon absorption single-event effects testing are used to investigate these phenomena. The implications of these results for highly-scaled technologies are also discussed. [ABSTRACT FROM PUBLISHER]

Single particle displacement damage events are reported in silicon diodes irradiated with ^252Cf and ^241Am. In situ measurements of reverse current show the result of displacement damage incurred from individual fission fragments in ^252Cf irradiated diodes. Discrete increases in reverse current exceeding 20 fA are measured. The increases are temporally correlated with fission fragment-induced ionization events. The ratio of the damage factor associated with fission fragments to the damage factor associated with alpha particles is in good agreement with the ratio of non-ionizing energy loss calculated for fission fragments to NIEL calculated for alpha particles. [ABSTRACT FROM AUTHOR]

Charge collection measurements reveal that the presence of high-Z materials increases proton-induced charge collection cross sections for high charge collection events. The mechanism for this effect is proton-induced fission events as shown through validated Monte Carlo simulations. These fission fragments are emitted isotropically in contrast to high-LET secondary particles from proton-silicon interactions which tend to be forward directed. [ABSTRACT FROM AUTHOR]