Computer Simulation and Experimental Performance Data for an Electron Spectrometer for Electron Beam Testing of Integrated Circuits

Electron beam testing using voltage contrast in the scanning electron microscope has been established as a useful tool for nondestructive and nonloading functional testing and failure analysis of integrated circuits (IC). The accuracy of quantitative voltage measurements within the IC with the electron beam probe is determined by the performance of the secondary electron (SE) spectrometer used. For simulating the performance of SE-spectrometers a program-package has been developed by aid of which the voltage-and field-distributions within the spectrometers can be evaluated using a finite element method. Thus it is possible to trace electron trajectories throughout the spectrometer. By considering a great number of SE-trajectories, the detected integral SE-signal for different voltages at the IC can be determined as a function of the retarding field voltage within the spectrometer. In this way the performance of an existing spectrometer is simulated. The experimentally measured SE-signals are compared with the simulation data. This comparison showed that the program-package realistically simulates the spectrometer properties. Therefore this program-package enables an improvement of existing SE-spectrometers and in principle also the development of new spectrometer-assemblies. Here the suitability for optimizing a SE-spectrometer is shown

Influence of dissolved hydrogen on the dislocation nucleation during plastic deformation of metals

Gelöster Wasserstoff in Metallen führt in vielen Fällen zu einer Reduzierung der Güte von mechanischen Eigenschaften. Dies äußert sich auf vielfältige Weise und wird unter dem Begriff Wasserstoffversprödung zusammengefasst. Für ein grundlegendes Verständnis dieses Phänomens müssen die Vorgänge im Metall auf mikroskopischer Skala ergründet werden. Im Rahmen dieser Arbeit wurde daher ein Aspekt der Wasserstoffversprödung, die Interaktion von Wasserstoff mit Versetzungen, näher untersucht. Zur Untersuchung des Einflusses von Wasserstoff auf die Versetzungsbildung wurden verschiedene Verformungsexperimente an Palladium und Vanadium durchgeführt. Prinzipielle Vorgänge der Defektbildung wurden durch Versuche an einzelnen Versetzungen unter Verwendung von Nanoindentation und Zugexperimenten im ETEM durchgeführt, um einen breiten Überblick zu erlangen. Zusätzlich wurden zum besseren Verständnis der Vorgänge Molekulardynamiksimulationen von derartigen Versuchen ausgeführt. Zur Untersuchung der Interaktion von Versetzungen miteinander wurden Säulen im Mikrometerbereich verformt und Blech durch Kaltwalzen verformt. Des Weiteren wurde durch Hochdruck-Torsion maximale Verformungen realisiert. Die verwendeten Modellmaterialien erlauben es verschiedene prinzipielle Vorgänge der Defektbildung zu untersuchen und so einen breiten Überblick über prinzipielle Vorgänge im kfz Gitter (Palladium) bzw. krz Gitter (Vanadium) zu erhalten

Effect of annealing on point defect population in cold-drawn pearlitic steel wires

Cold-drawn pearlitic steel wires were subjected to differential scanning calorimetry and resistivity measurements during heating. Both techniques yield two peaks, one at 500-600 K, the other at 400-450 K. Whereas the peak at 500-600 K can be ascribed to voids consisting of about 10 vacancies as confirmed by positron annihilation spectroscopy, the low-temperature peak is ascribed to V1C2 and/or V2C4 complexes. © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved

The effect of hydrogen-deformation interactions on the recrystallization of β-21S titanium alloys

International audienceIn order to get a better understanding on the hydrogen-deformation interactions on the recrystallization of titanium alloys, solution-annealed and cold-rolled β-21S titanium samples were electrolytically charged with hydrogen under various charging conditions. It was observed that the lattice parameter of cubic body centered the βp-phase increased proportionally to the charging time without any formation of hydride while the charging current density appeared to have no significant effect on the variation of the lattice parameter. However our results indicated that the pre-plastic deformation (cold rolling) enhanced the hydrogen absorption capacity in the specimens. The effects of hydrogen on the plastic-deformation and recrystallization of β-21S titanium alloy has been investigated by a systematic analysis of the microstructures by means of X-ray diffraction and SEM coupled with Electron Back-Scatter Diffraction

Relationship between hydrogen embrittlement and Md30 temperature: Prediction of low-nickel austenitic stainless steel's resistance

Hydrogen embrittlement (HE) of several low-nickel austenitic stainless steels (AISI 300 series) was studied with special attention to the impact of strain induced α′-martensite. The susceptibility of the steels to HE is judged with respect to the relative reduction of area (RRA): The HE susceptibility is lower for larger RRA-values. Strain-induced martensite formation was evaluated within in the framework of the Olson-Cohen model, revealing a linear relationship between RRA and the probability β of martensite nucleus formation in the steels. In order to widen the scope of data evaluation to literature data, the consideration of a parameter alternative to β is required. It is demonstrated that among other parameters the Md30 temperature (Nohara), which assesses the stability against martensitic transformation, can serve as an indicator to predict HE of AISI 300 series steels. Regarding the Md30 temperature (Nohara), a trend-line with respect to the RRA-values is found. Thereby, the RRA-values of low-nickel austenitic stainless steels group into three distinct regimes; (1) for Md30 > −80 °C, where RRA-values decrease with increasing Md30 temperature, (2) at Md30 ≈ −80 °C, where RRA-values show a large variation (‘threshold band’), and (3) for Md30 < −80 °C, showing constant RRA-values of nearly 100%. Some RRA data points that deviate from the trend line can be explained by the special microstructure of the investigated samples.Fil: Izawa, Chika. Universität Göttingen; AlemaniaFil: Wagner, Stefan. Karlsruher Institut für Technologie; AlemaniaFil: Deutges, Martin. Universität Göttingen; AlemaniaFil: Martín, Mauro Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Weber, Sebastian. Bergische Universität Wuppertal; AlemaniaFil: Pargeter, Richard. The Welding Institute; Reino UnidoFil: Michler, Thorsten. Opel Automobile; AlemaniaFil: Uchida, Haru Hisa. Tokai University; JapónFil: Gemma, Ryota. Tokai University; JapónFil: Pundt, Astrid. Universität Göttingen; Alemania. Karlsruher Institut für Technologie; Alemani