TY - JOUR A1 - Procop, Mathias A1 - Hodoroaba, Vasile-Dan T1 - X-ray fluorescence as an additional analytical method for a scanning electron microscope JF - Microchimica acta N2 - Energy dispersive and wavelength dispersive X-ray spectrometry are used to determine the composition of a specimen in a scanning electron microscope (SEM) by electron probe microanalysis (EPMA). A valuable completion for the SEM is analysis by X-ray fluorescence (XRFA). The main advantage of this method consists in its low detection limit. XRFA with a SEM uses the same spectrometers as for EPMA, necessary are only an additional X-ray source for the excitation of fluorescence spectra and software for their evaluation. Recent developments of smart low-power X-ray tubes and X-ray optical components enabled the construction of compact X-ray sources with focussing properties as add-on for a SEM. For quantitative XRFA the source spectrum has to be known. For its calculation the X-ray production yields Y have been measured for the commonly used tube target materials Mo, Rh and W. The excitation spectra were calculated for a variety of source types and compared with respect to the achievable photon flux and its spectral distribution. KW - X-ray spectroscopy KW - X-ray production yield KW - X-ray tube spectrum KW - X-ray fluorescence analysis KW - XRF KW - X-ray optics KW - Scanning electron microscopy KW - Analytical SEM PY - 2008 DO - https://doi.org/10.1007/s00604-007-0854-4 SN - 0026-3672 SN - 1436-5073 VL - 161 IS - 3-4 SP - 413 EP - 419 PB - Springer CY - Wien AN - OPUS4-17537 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Procop, Mathias A1 - Hodoroaba, Vasile-Dan T1 - A test material and a quick procedure for the performance check of X-ray spectrometers attached to the SEM JF - Microscopy and microanalysis PY - 2009 DO - https://doi.org/10.1017/S143192760909432X SN - 1431-9276 SN - 1435-8115 VL - 15 IS - Suppl. 2 SP - 1120 EP - 1121 PB - Cambridge University Press CY - New York, NY AN - OPUS4-19793 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Procop, Mathias A1 - Hodoroaba, Vasile-Dan A1 - Bjeoumikhov, A. T1 - Calculation of X-ray spectra for a side window tube JF - Microscopy and microanalysis T2 - Microscopy and Microanalysis CY - Chicago, IL, United States of America DA - 2006-07-30 KW - X-ray spectroscopy KW - X-ray tube KW - Microanalysis KW - XRF PY - 2006 DO - https://doi.org/10.1017/S143192760606123X SN - 1431-9276 SN - 1435-8115 VL - 12 IS - Supplement 2 PB - Cambridge University Press CY - New York, NY AN - OPUS4-12667 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Procop, Mathias A1 - Hodoroaba, Vasile-Dan A1 - Bjeoumikhov, A. A1 - Wedell, R. A1 - Warrikhoff, A. T1 - Improvements of the low-energy performance of a micro-focus x-ray source for XRF analysis with the SEM JF - X-ray spectrometry N2 - X-ray Fluorescence (XRF) with a scanning electron microscope (SEM) is a valuable completion of the analytical capabilities of SEMs. Small and compact micro-focus x-ray sources are mounted to the microscope chamber, and the x-ray spectra are monitored with conventional EDS systems. Up to now the x-ray tubes used for the micro-focus x-ray sources are equipped with beryllium windows about 100 µm thick. The poly-capillary x-ray lenses have their transmission maximum at photon energies around 10 keV. It drops down in both low- and high-energy ranges. Hence, L-radiation from an Mo or Rh target will be strongly attenuated, and the excitation of fluorescence in the soft x-ray range becomes very ineffective. A new micro-focus x-ray source was developed. It is characterised by a lower self-absorption in the tube target, thin beryllium windows and an x-ray optics having a large distance between its foci and the maximum of transmission at about 5 keV. Thus K line fluorescence of light elements becomes effectively excited by the L-radiation from Mo or Rh tube targets. The detection limit for sodium oxide in glass was found to be below 1 mass%. KW - Micro-focus-XRF KW - X-ray tube KW - X-ray optics KW - SEM PY - 2009 DO - https://doi.org/10.1002/xrs.1159 SN - 0049-8246 VL - 38 IS - 4 SP - 308 EP - 311 PB - Wiley CY - Chichester AN - OPUS4-19583 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Procop, Mathias A1 - Hodoroaba, Vasile-Dan A1 - Griepentrog, Michael T1 - A new material for the performance check of X-ray spectrometers attached to a SEM JF - Microscopy and microanalysis T2 - Microscopy and Microanalysis 2006 CY - Chicago, IL, USA DA - 2006-07-30 KW - X-ray spectrometer KW - EDS KW - WDS KW - Calibration PY - 2006 DO - https://doi.org/10.1017/S1431927606061307 SN - 1431-9276 SN - 1435-8115 VL - 12 IS - Supplement 2 SP - 870 EP - 871 PB - Cambridge University Press CY - New York, NY AN - OPUS4-12665 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Procop, Mathias A1 - Hodoroaba, Vasile-Dan A1 - Terborg, R. A1 - Berger, D. T1 - Determination of the Effective Detector Area of an Energy-Dispersive X-Ray Spectrometer at the Scanning Electron Microscope Using Experimental and Theoretical X-Ray Emission Yields JF - Microscopy and Microanalysis N2 - A method is proposed to determine the effective detector area for energy-dispersive X-ray spectrometers (EDS). Nowadays, detectors are available for a wide range of nominal areas ranging from 10 up to 150mm2. However, it remains in most cases unknown whether this nominal area coincides with the “net active sensor area” that should be given according to the related standard ISO 15632, or with any other area of the detector device. Moreover, the specific geometry of EDS installation may further reduce a given detector area. The proposed method can be applied to most scanning electron microscope/EDS configurations. The basic idea consists in a comparison of the measured count rate with the count rate resulting from known X-ray yields of copper, titanium, or silicon. The method was successfully tested on three detectors with known effective area and applied further to seven spectrometers from different manufacturers. In most cases the method gave an effective area smaller than the area given in the detector description. KW - Energy-dispersive X-ray spectrometer (EDS) KW - EDX KW - Effective area KW - X-ray emission yield KW - Geometrical collection efficiency PY - 2016 UR - https://www.cambridge.org/core/journals/microscopy-and-microanalysis/article/div-classtitledetermination-of-the-effective-detector-area-of-an-energy-dispersive-x-ray-spectrometer-at-the-scanning-electron-microscope-using-experimental-and-theoretical-x-ray-emission-yieldsdiv/E15B2E67C349201CF323E778EB9C6D94 DO - https://doi.org/10.1017/S1431927616011788 VL - 22 IS - 6 SP - 1360 EP - 1368 PB - Cambridge University Press CY - New York, NY, USA AN - OPUS4-38858 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Procop, Mathias A1 - Hübner, Wolfgang A1 - Wäsche, Rolf A1 - Nieland, S. A1 - Ehrmann, O. T1 - Fast Elemental Mapping in Materials Science JF - European microscopy and analysis KW - Electron probe microanalysis KW - EPMA KW - Energy dispersive X-ray spectroscopy KW - EDS KW - Elemental mapping PY - 2002 UR - http://www.microscopy-analysis.com/sites/default/files/magazine_pdfs/mag%20179_2002_Jan_Procop_1.pdf SN - 0958-1952 IS - January SP - 5 EP - 6 PB - Rolston Gordon Comm. CY - Bookham, Surrey AN - OPUS4-7091 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Procop, Mathias A1 - Klein, A. A1 - Rechenberg, I. A1 - Krüger, D. T1 - AES Depth Profiling of Semiconducting Epitaxial Layers with Thicknesses in the Nanometre Range Using an Ion Beam Bevelling Technique JF - Surface and interface analysis KW - AES KW - Depth profiling KW - Ion beam bevelling PY - 1997 SN - 0142-2421 SN - 1096-9918 VL - 25 SP - 458 EP - 463 PB - Wiley CY - Chichester AN - OPUS4-7098 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Procop, Mathias A1 - Radtke, Martin A1 - Krumrey, M. A1 - Hasche, K. A1 - Schädlich, S. A1 - Frank, W. T1 - Electron probe microanalysis (EPMA) measurement of thin-film thickness in the nanometre range JF - Analytical and bioanalytical chemistry N2 - The thickness of thin films of platinum and nickel on fused silica and silicon substrates has been determined by EPMA using the commercial software STRATAGEM for calculation of film thickness. Film thickness ranged in the order 10 nm. An attempt was made to estimate the confidence range of the method by comparison with results from other methods of analysis. The data show that in addition to the uncertainty of the spectral intensity measurement and the complicated fitting routine, systematic deviation caused by the underlying model should be added. The scattering in the results from other methods does not enable specification of a range of uncertainty, but deviations from the real thickness are estimated to be less than 20%. KW - Electron probe microanalysis KW - EPMA KW - Thin films KW - Thickness measurement KW - X-rays PY - 2002 DO - https://doi.org/10.1007/s00216-002-1514-5 SN - 1618-2642 SN - 1618-2650 VL - 374 SP - 631 EP - 634 PB - Springer CY - Berlin AN - OPUS4-7090 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Procop, Mathias A1 - Röder, A. T1 - An interlaboratory comparison of energy dispersive X-ray microanalysis (EDX) of titanium and zirkonium nitrides JF - Microchimica acta N2 - The results of an interlaboratory comparison of energy dispersive X-ray microanalysis of TiN0.84 and ZrN were presented. The microprobe group of the German Physical Society (DPG) and the Federal Institute for Materials Research and Testing (BAM) had initiated the interlaboratory comparison. The primary aim was to test modern EDX systems equipped with ultrathin windows concerning the accuracy and reliability of the analysis of compounds containing light elements. The participants from 23 laboratories performed the analysis at different primary energies, in the standard-less mode as well as on the base of own standards, and considering Ti-K or Ti-L in case of TiN0.84. The results show a slight overestimation of the nitrogen content and a large standard deviation from the mean value. Reasons for the scattering of the results are discussed. T2 - 8th Symposium on Solid State Analysis DA - 1995-07-03 KW - Titanium nitride KW - Zirconium nitride KW - EDX KW - X-rays KW - Microanalysis PY - 1997 DO - https://doi.org/10.1007/BF01246159 SN - 0026-3672 SN - 1436-5073 VL - 125 IS - 1-4 SP - 33 EP - 39 PB - Springer CY - Wien AN - OPUS4-7089 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Procop, Mathias A1 - Scholze, F. T1 - Synchrotron Radiation for the Characterization of Energy Dispersive X-ray Spectrometers JF - Microscopy and microanalysis KW - Röntgenspektroskopie KW - Detektoren KW - Elektronenstrahl-Mikroanalyse KW - ESMA KW - EPMA KW - Röntgenfluoreszenzanalyse KW - RFA KW - XRF PY - 2004 DO - https://doi.org/10.1017/S1431927604880152 SN - 1431-9276 SN - 1435-8115 VL - 10 IS - 2 SP - 98 EP - 99 PB - Cambridge University Press CY - New York, NY AN - OPUS4-3720 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Procop, Mathias A1 - Scholze, F. T1 - Measurement of detection efficiency and response functions for an Si(Li) x-ray spectrometer in the range 0.1-5 keV JF - X-ray spectrometry N2 - Efficiency and response functions were determined for a modern commercial energy-dispersive x-ray spectrometer in the photon energy range 0.1-5 keV using dispersed and undispersed synchrotron radiation. The spectrometer was equipped with an Si(Li) detector crystal, a thin-film window and a digital pulse processor. Monochromatized synchrotron radiation from the PTB VUV radiometry beamline at the electron storage ring BESSY was used for the absolute determination of the detection efficiency with a typical relative uncertainty of 1-2% in the photon energy range 0.1-1.5 keV by direct comparison with calibrated photodiodes. At higher photon energies, the efficiency was found by comparison of the measured and calculated undispersed synchrotron radiation spectrum. The absolute intensity of the synchrotron radiation was known with a relative uncertainty of less than 1%. In the overlapping region, the results from the two independent experiments are in full agreement. The energy dependence of the measured efficiency can be explained only with a detector model assuming that there is no dead layer. A simple model for the effect of incomplete charge collection (ICC) was applied to describe the measured response functions. Consequences of the ICC such as broadening and shift of low-energy peaks and redistribution of counts around 1.84 keV are explained with the model, in accordance with the experimental results. PY - 2001 DO - https://doi.org/10.1002/xrs.472 SN - 0049-8246 VL - 30 IS - 2 SP - 69 EP - 76 PB - Wiley CY - Chichester AN - OPUS4-1120 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Procop, Mathias A1 - Terborg, R. T1 - Measurement and calculation of x-ray production efficiencies for copper, zirconium, and tungsten JF - Microscopy and microanalysis N2 - Electron probe microanalysis (EPMA) is based on physical relations between measured X-ray intensities of characteristic lines and their Xray production efficiency, which depends on the specimen composition. The quality of the analysis results relies on how realistically the physical relations describe the generation and emission of X-rays. Special experiments are necessary to measure X-ray production efficiencies. A challenge in these experiments is the determination of the detection efficiency of the spectrometer as a function of the photon energy. An energy-dispersive spectrometer was used in this work, for which the efficiency was determined at metrological synchrotron beamlines with an accuracy of ±2%. X-ray production efficiencies for the L series and the Kα series of copper and zirconium and for the M and L series of tungsten were determined at energies up to 30 keV in a scanning electron microscope. These experimental values were compared with calculated X-ray production efficiencies using physical relations and material constants applied in EPMA. The objective of the comparison is the further improvement of EPMA algorithms as well as extending the available database for X-ray production efficiencies. Experimental data for the X-ray production efficiency are also useful for the assessment of spectrum simulation software. KW - Copper KW - Electron probe microanalysis KW - Tungsten KW - X-ray production efficiency KW - Zirconium PY - 2022 DO - https://doi.org/10.1017/S1431927622012351 VL - 28 IS - 6 SP - 1865 EP - 1877 PB - Oxford University Press CY - Oxford AN - OPUS4-55711 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scholze, F. A1 - Procop, Mathias T1 - Detection efficiency of energy-dispersive detectors with low-energy windows JF - X-ray spectrometry N2 - Energy dispersive X-ray spectrometry offers the opportunity for fast composition determination of specimens by X-ray fluorescence or electron probe microanalysis. For fundamental parameter based quantification, the knowledge of the detection efficiency of the spectrometer is essential. At low energies the efficiency is strongly influenced by X-ray absorption in the radiation entrance window. State-of-the-art windows consist of polymer foil containing C, N, and O, coated with Al and in some cases with a special B compound. The foil is supported by a Si grid to withstand the atmosphere pressure. The absorption of all these components must be known to describe the detection efficiency. The transmittance of three types of widely used commercial windows has been measured. Transmittance curves have been fitted by analytical expressions using tabulated mass absorption coefficients. Because tabulated mass absorption coefficients do not consider near edge effects, there are strong deviations between measured and calculated transmittance below 0.6 keV. It is proposed to model the spectrometer efficiency by the measured window transmittance and calculated absorptions from front contact and possible contaminations. This reduces the number of unknown parameters drastically. PY - 2005 DO - https://doi.org/10.1002/xrs.859 SN - 0049-8246 VL - 34 IS - 6 SP - 473 EP - 476 PB - Wiley CY - Chichester AN - OPUS4-11936 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Terborg, R. A1 - Procop, Mathias T1 - Theoretical calculation and experimental determination of x-ray production efficiencies for copper, zirconium, and tungsten JF - Microscopy and microanalysis N2 - The X-ray intensities of the K-, L- and M-lines of copper, zirconium and tungsten have been measured with an energy-dispersive X-ray spectrometer of known efficiency as function of photon energy. X-ray production efficiencies were determined from the measured intensities for Kα- and L-series of Cu and Zr and for the L- and M-series of W. These data were compared to calculated X-ray production efficiencies based on the widely used matrix correction models of Pouchou and Pichoir (XPP) and Bastin (PROZA96). Our results indicate that a replacement of the stopping power in the PROZA96 algorithm by expressions of Joy and Jablonski has only a minor influence on the calculated X-ray production efficiencies. In contrast, the modifications of the ionization cross-section show a stronger effect. We replaced the ionization cross-sections for K lines of the PROZA96 algorithm with different models. The results for L- and M-Lines are different. For the L-lines of Cu the original XPP and PROZA96 models show the best agreement while using the Bote cross-sections result in an overestimation. For the Zr-L and W-L1, -L2, -L3 X-ray production efficiencies, the Bote cross-sections lead to a significant improvement compared to all other models. The original XPP model represents the best agreement for the M5 efficiencies but underestimates the M4 efficiencies. There is no superior model or modification because the parameter sets in the models need to be aligned to each other. However, using the ionization cross-sections of Bote, which are based on quantum mechanical calculations, show promising results in many cases. KW - X-ray production efficiency KW - EPMA KW - Copper KW - Zirconium KW - Tungsten PY - 2023 DO - https://doi.org/10.1093/micmic/ozad067.110 SN - 1435-8115 VL - 29 IS - Supplement 1 SP - 245 EP - 246 PB - Oxford University Press CY - Oxford AN - OPUS4-58339 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Thomsen-Schmidt, P. A1 - Hasche, K. A1 - Ulm, G. A1 - Herrmann, K. A1 - Krumrey, M. A1 - Ade, G. A1 - Stümpel, J. A1 - Busch, I. A1 - Schädlich, S. A1 - Schindler, A. A1 - Frank, W. A1 - Hirsch, D. A1 - Procop, Mathias A1 - Beck, Uwe T1 - Realisation and metrological characterisation of thickness standards below 100 nm JF - Applied physics A N2 - High-accuracy film thickness measurements in the range below 100 nm can be made by various complex methods like spectral ellipsometry (SE), scanning force microscopy (SFM), grazing incidence X-ray reflectometry (GIXR), or X-ray fluorescence analysis (XRF). The measurement results achieved with these methods are based on different interactions between the film and the probe. A key question in nanotechnology is how to achieve consistent results on a level of uncertainty below one nanometre with different techniques. Two different types of thickness standards are realised. Metal film standards for X-ray techniques in the thickness range 10 to 50 nm are calibrated by GIXR with monochromatised synchrotron radiation of 8048 eV. The results obtained at four different facilities show excellent agreement. SiO2 on Si standards for SE and SFM in the thickness range 6 to 1000 nm are calibrated by GIXR with monochromatised synchrotron radiation of 1841 eV and with a metrological SFM. Consistent results within the combined uncertainties are obtained with the two methods. Surfaces and interfaces of both types of standards are additionally investigated by transmission electron microscopy (TEM). PY - 2004 DO - https://doi.org/10.1007/s00339-003-2273-7 SN - 0947-8396 VL - 78 IS - 5 SP - 645 EP - 649 PB - Springer CY - Berlin AN - OPUS4-17195 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wandel, K. A1 - Procop, Mathias A1 - Richter, U. A1 - Wolf, R. T1 - The influence of the storage time and the deposition of SiO2 on the properties of H2SO4 etched (In,Ga) As surface layers investigated by XPS and ellipsometry JF - Semiconductor science and technology PY - 1993 SN - 0268-1242 SN - 1361-6641 VL - 8 SP - 1438 EP - 1444 PB - IOP Publ. CY - Bristol AN - OPUS4-7087 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -