175 research outputs found
GIXRF In The Soft X-Ray Range Used For The Characterization Of Ultra Shallow Junctions
No full textGrazing Incidence X-Ray Fluorescence (GIXRF) analysis in the soft X-ray range provides excellent conditions for exciting B-K and As-Liii,ii shells. The X-ray Standing Wave field (XSW) associated with GIXRF on flat samples is used as a tunable sensor to gain information about the implantation profile in the nm range due to the in-depth changes of the XSW intensity dependent on the angle between the sample surface and the primary beam. This technique is very sensitive to near surface layers. It is therefore well suited for the study of ultra shallow dopant distributions. Arsenic implanted (100) Si wafers with nominal fluence between 1.0E14 cm−2 and 5.0E15 cm−2 and implantation energies between 0.5 keV and 5.0 keV and Boron implanted (100) Si wafers with nominal fluence of 1.0E14 cm−2 and 5.0E15 cm−2 and implantation energies between 0.2 keV and 3.0 keV have been used to compare SIMS analysis with synchrotron radiation induced GIXRF analysis in the soft X-ray range. The measurements have been carried out at the laboratory of the Physikalisch-Technische Bundesanstalt at the electron storage ring BESSY II using monochromatized undulator radiation of well-known radiant power and spectral purity. Here the use of an absolutely calibrated energy-dispersive detector for the registration of the B-K and As-L fluorescence radiation allows for the absolute determination of the total retained dose. An estimate of the concentration profile has been obtained by fitting the X-ray fluorescence angular scans with profiles derived by simulation of the implantation process. A good match among the total retained dose measured with the different techniques has been observed
Unveiling the effect of substrate on graphene via non-destructive multiscale Raman spectroscopy
No full textGraphene has now become a frontier material for various industrial applications due to its remarkable properties such as high electrical conductivity, exceptional mechanical strength and thermal conductivity. Indeed, the quality control of the produced graphene is one of the main issues to be solved for its successful application in various technologies such as flexible electronics, energy storage devices and advanced composites.The samples subject to this study were produced by Graphenea during the work of the H2020 European project CHALLENGES (realtime nano CHAracterization reLatEd techNoloGiES); in particular, these samples consists of graphene grown on copper substrates and then transferred to silicon with different values of resistivity. These samples were then characterised by the Physikalisch-Technische Bundesanstalt (PTB) and the Sapienza University of Rome. The study was mainly focused on the application of advanced optical non-destructive characterisation techniques, in particular correlative microscopy (Atomic Force Microscopy and Raman spectroscopy) and Tip-Enhanced Raman Spectroscopy (TERS), to evaluate their application for in-line quality control. Using monochromatic laser light, Raman spectroscopy can reveal valuable information about strain, defects and compositional variations, while the non-invasive nature of these techniques makes them ideal for industrial applications, allowing real-time monitoring without compromising sample integrity but with relatively low spatial resolution (diffraction-limited). In addition to conventional correlative microscopy using Raman spectroscopy and atomic force microscopy (AFM), tip-enhanced Raman spectroscopy (TERS) is emerging as a powerful tool in the arsenal of graphene characterisation techniques. Combining the high spatial resolution of scanning probe microscopy with the sensitivity of Raman spectroscopy, TERS provides not only high-resolution topographical information, but also rapid chemical mapping of graphene at the nanoscale thanks to the plasmonic effect at the tip. This technique reveals nuances in strain distribution and compositional defects at the nanoscale level, providing unprecedented insight into the local properties of graphene. Understanding the strain and compositional defects in graphene grown on copper and after transfer to silicon is crucial for tailoring the material for specific applications. The choice of substrate can significantly affect the electronic and mechanical properties of graphene, so comprehensive characterisation using advanced optical techniques is essential
Depth profile characterization of ultra shallow junction implants
No full textA need for analysis techniques, complementary to secondary ion mass spectrometry (SIMS), for depth profiling dopants in silicon for ultra shallow junction (USJ) applications in CMOS technologies has recently emerged following the difficulties SIMS is facing there. Grazing incidence X-ray fluorescence (GIXRF) analysis in the soft X-ray range is a high-potential tool for this purpose. It provides excellent conditions for the excitation of the B-K and the As-L iii,ii shells. The X-ray standing wave (XSW) field associated with GIXRF on flat samples is used here as a tunable sensor to obtain information about the implantation profile because the in-depth changes of the XSW intensity are dependent on the angle of incidence. This technique is very sensitive to near-surface layers and is therefore well suited for the analysis of USJ distributions. Si wafers implanted with either arsenic or boron at different fluences and implantation energies were used to compare SIMS with synchrotron radiation-induced GIXRF analysis. GIXRF measurements were carried out at the laboratory of the Physikalisch-Technische Bundesanstalt (PTB) at the electron storage ring BESSY II using monochromatized undulator radiation of well-known radiant power and spectral purity. The use of an absolutely calibrated energy-dispersive detector for the acquisition of the B-Kα and As-Lα fluorescence radiation enabled the absolute determination of the total retained dose. The concentration profile was obtained by ab initio calculation and comparison with the angular measurements of the X-ray fluorescence
Improvement of total reflection X-ray fluorescence analysis of low Z elements on silicon wafer surfaces at the PTB monochromator beamline for undulator radiation at the electron storage ring BESSY II,
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Traceable Characterization of Nanomaterials by X-ray Spectrometry Using Calibrated Instrumentation
No full textTraceable characterization methods allow for the accurate correlation of the functionality or toxicity of nanomaterials with their underlaying chemical, structural or physical material properties. These correlations are required for the directed development of nanomaterials to reach target functionalities such as conversion efficiencies or selective sensitivities. The reliable characterization of nanomaterials requires techniques that often need to be adapted to the nano-scaled dimensions of the samples with respect to both the spatial dimensions of the probe and the instrumental or experimental discrimination capability. The traceability of analytical methods revealing information on chemical material properties relies on reference materials or qualified calibration samples, the spatial elemental distributions of which must be very similar to the nanomaterial of interest. At the nanoscale, however, only few well-known reference materials exist. An alternate route to establish the required traceability lays in the physical calibration of the analytical instrument’s response behavior and efficiency in conjunction with a good knowledge of the various interaction probabilities. For the elemental analysis, speciation, and coordination of nanomaterials, such a physical traceability can be achieved with X-ray spectrometry. This requires the radiometric calibration of energy- and wavelength-dispersive X-ray spectrometers, as well as the reliable determination of atomic X-ray fundamental parameters using such instrumentation. In different operational configurations, the information depths, discrimination capability, and sensitivity of X-ray spectrometry can be considerably modified while preserving its traceability, allowing for the characterization of surface contamination as well as interfacial thin layer and nanoparticle chemical compositions. Furthermore, time-resolved and hybrid approaches provide access to analytical information under operando conditions or reveal dimensional information, such as elemental or species depth profiles of nanomaterials. The aim of this review is to demonstrate the absolute quantification capabilities of SI-traceable X-ray spectrometry based upon calibrated instrumentation and knowledge about X-ray interaction probabilities
Liquid Phase Adsorption of Sulfur on Germanium Reaction Mechanism and Atomic Geometry
No full textWe present a fundamental study of the monolayer adsorption of sulfur on Ge(100) surfaces from aqueous (NH4)2S solution. This treatment shows promising perspectives for the passivation of high-mobility semiconductor surfaces and is therefore presently of great technological importance. The adsorption mechanisms as well as the adsorption geometry are thoroughly investigated at the atomic scale, by both experiment and theory, applying X-ray absorption spectroscopy and molecular dynamics simulations. Our findings indicate that sulfidation in solution results in the formation of Ge-S-Ge bridges along the [110] direction, with no indication for -SH surface groups. A S-Ge bond length of 2.25 ± 0.05 Å was deduced, which is affected by the chemical environment of the sulfur atoms, i.e., by residual surface oxides. Our study provides novel insights into the surface termination and atomic structure of (NH4)2S-treated Ge(100) surfaces and discusses possible differences from in situ sulfur adsorption methods such as H2S or S2 exposure. © 2013 American Chemical Society.sponsorship: This work has been supported by the Research Foundation Flanders (FWO), the KU Leuven BOF research programs (GOA/09/006 and PDMK/11/150), as well as by the Odysseus program of the Flemish Government. The X-ray absorption measurements were supported by the European Commission-Research Infrastructure Action under the FP6 "European Integrated Activity of Excellence and Networking for Nano- and Micro-Electronics Analysis" - Project number 026134 (RI3) ANNA. We thank Prof. R. E. Palmer for access to the High Resolution EELS spectrometer. Useful suggestions by S. Sioncke and C. Adelmann (IMEC, Leuven, Belgium) are gratefully acknowledged. (Research Foundation Flanders (FWO), KU Leuven BOF research programs|GOA/09/006, KU Leuven BOF research programs|PDMK/11/150, Flemish Government, European Commission|026134 (RI3) ANNA)status: Publishe
Online Visualisierung der Elementverteilungen für Messungen mit einem Röntgenfluoreszenz-Mikroskop an PETRA III
No full textDie Röntgenfluoreszenz-Mikroskopie ist ein präzises, zerstörungsfreies und bildgebendes Verfahren zur Bestimmung der Elementverteilungen einer Probe mit einer räumlichen Auflösung im Submikrometerbereich. Röntgenstrahlung wird dafür auf einen möglichst kleinen Bereich in der Probenebene fokussiert und schrittweise oder kontinuierlich verfahren. Für jedes Pixel wird ein Röntgenfluoreszenzspektrum aufgenommen, aus dem aus den charakteristischen Röntgenlinien die chemische Zusammensetzung bestimmt werden kann. Für ein gutes Signal-Rausch-Verhältnis müssen die Messungen über einen langen Zeitraum oder bei hohen Eingangszählraten am Detektor durchgeführt werden. Letztere können bei Messungen mit brillianter Synchrotonstrahlung, wie an PETRA III am DESY in Hamburg, erreicht werden.Um einschätzen zu können, ob der abgerasterte Bereich auf der Probe uninteressant ist oder Artefakte aufweist und die Messung vorzeitig abgebrochen werden kann, sollten die groben Elementverteilungen bereits während der Messung visualisiert werden. Ziel meiner Arbeit war es, zwischen dem Messrechner und einem weiteren Rechner eine schnelle, sichere und vollständige Datenkommunikation herzustellen, sodass der anfallende binäre Datenstrom auf dem zweiten Rechner möglichst schnell interpretiert, ausgewertet und die Elementverteilung auf dem Bildschirm graphisch dargestellt werden kann. Die Kommunikation wird über ZeroMQ-Sockets realisiert und die Auswertung der Röntgenfluoreszenzspektren erfolgt über die ROI-Methode. Das während meiner Arbeit erstellte Python-Programm ermöglicht bei Zählraten bis 500 000 Signalen pro Sekunde eine Visualisierung der Elementverteilung in Echtzeit, die während der Messung fortgehend aktualisiert wird
Metrologie mit Synchrotronstrahlung, Teil II (Auszug aus: PTB-Mitteilungen 2014, Band 124, Heft 4. ISSN 0030-834X)
No full textPTB-Mitteilungen. Band 124 (2014), Heft 4. ISSN 0030-834X1.:
Scholze, Frank, Christian Laubis, Annett Barboutis, Christian Buchholz, Andreas Fischer, Jana Puls und Christian Stadelhoff: Radiometrie für die EUV-Lithographie.
doi: 10.7795/310.20140401 http://dx.doi.org/10.7795/210.20140401
2.:
Scholze, Frank, Anton Haase, Michael Krumrey, Victor Soltwisch und Jan Wernecke: Streuverfahren an nanostrukturierten Oberflächen.
doi: 10.7795/310.20140402 http://dx.doi.org/10.7795/310.20140402
3.:
Krumrey, Michael, Raul Garcia-Diez, Christian Gollwitzer und Stefanie Langner: Größenbestimmung von Nanopartikeln mit Röntgenkleinwinkelstreuung.
doi: 10.7795/310.20140403 http://dx.doi.org/10.7795/310.20140403
4.:
Müller, Matthias, Martin Gerlach, Ina Holfelder, Philipp Hönicke, Janin Lubeck, Andreas Nutsch, Beatrix Pollakowski, Cornelia Streeck, Rainer Unterumsberger, Jan Weser und Burkhard Beckhoff: Röntgenspektrometrie mit Synchrotronstrahlung.
doi: 10.7795/310.20140404 http://dx.doi.org/10.7795/210.20140404
5.:
Hermann, Peter, Arne Hoehl, Andrea Hornemann, Bernd Kästner, Ralph Müller, Burkhard Beckhoff und Gerhard Ulm: Mikro- und Nano-Spektroskopie und Detektorcharakterisierung im IR- und THz-Bereich an der Metrology Light Source.
doi: 10.7795/310.20140405 http://dx.doi.org/10.7795/310.20140405
6.:
Kolbe, Michael, Erik Darlatt, Rolf Fliegauf, Hendrik Kaser, Alexander Gottwald und Mathias Richter: Oberflächenuntersuchungen mit Vakuum-UV-Strahlung.
doi: 10.7795/310.20140406 http://dx.doi.org/10.7795/310.2014040
Improved quantitative XRF analysis of industrial thin film samples by calibration using thin film RMs certified by reference-free XRF enabling traceability to the SI
No full textReference-free XRF is a SI traceable technique for the
determination of the mass deposition (mass per unit area) of elements in films on the nano- and micro scale. The method is radiometrically calibrated instrumentation (PTB@BESSY II, Germany) and based on reliable knowledge of all relevant atomic fundamental, experimental and instrumental parameters. No calibration sample or reference materials are necessary. The approach had been validated in the CCQM-P140 pilot study and the K129 key comparison by determination of mole fractions in Cu(In,Ga)Se2 thin films
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