TY - JOUR A1 - Unger, Wolfgang A1 - Senoner, Mathias A1 - Wirth, Thomas A1 - Bütefisch, S. A1 - Busch, I. T1 - Lateral resolution delivered by imaging surface-analytical instruments as SIMS, AES and XPS: Application of the BAM-L200 Certified Reference Material and related ISO Standards N2 - The certified reference material BAM-L200, a nanoscale stripe pattern for length calibration and specification of lateral resolution, is described. BAM-L200 is prepared from a cross-sectioned epitaxially grown layer stack of AlxGa1-xAs and InxGa1 xAs on a GaAs substrate. The surface of BAM-L200 provides a flat pattern with stripe widths ranging down to 1 nm. Calibration distances, grating periods and stripe widths have been certified by TEM with traceability to the length unit. The combination of gratings, isolated narrow stripes and sharp edges of wide stripes offers a plenty of options for the determination of lateral resolution, sharpness and calibration of length scale at selected settings of imaging surface analytical instruments. The feasibility of the reference material for an analysis of the lateral resolution is demonstrated in detail by evaluation of ToF-SIMS, AES and EDX images. Other applications developed in the community are summarized, too. BAM-L200 fully supports the implementation of the revised International Standard ISO 18516 (in preparation) which is based on knowledge outlined in the Technical Report ISO/TR 19319:2013. KW - Standardization KW - AES KW - XPS KW - SIMS KW - Lateral resolution KW - Certified reference material PY - 2017 SN - 1341-1756 VL - 24 IS - 2 SP - 123 EP - 128 AN - OPUS4-43138 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kraffert, K. A1 - Karg, M. A1 - Schmack, R. A1 - Clavel, G. A1 - Boissiere, C. A1 - Wirth,, Thomas A1 - Pinna, N. A1 - Kraehnert, R. T1 - Stabilization of Mesoporous Iron Oxide Films against Sintering and Phase Transformations via Atomic Layer Deposition of Alumina and Silica N2 - The stabilization of crystal phases and nanostructured morphologies is an essential topic in application-driven design of mesoporous materials. Many applications, e.g. catalysis, require high temperature and humidity. Typical metal oxides transform under such conditions from a metastable, low crystal-line material into a thermodynamically more favorable form, i.e. from ferrihy-drite into hematite in the case of iron oxide. The harsh conditions induce also a growth of the crystallites constituting pore walls, which results in sintering and finally collapse of the porous network. Herein, a new method to stabi-lize mesoporous templated metal oxides against sintering and pore collapse is reported. The method employs atomic layer deposition (ALD) to coat the internal mesopore surface with thin layers of either alumina or silica. The authors demonstrate that silica exerts a very strong influence: It shifts hematite formation from 400 to 600 °C and sintering of hematite from 600 to 900 °C. Differences between the stabilization via alumina and silica are rationalized by a different interaction strength between the ALD material and the ferrihydrite film. The presented approach allows to stabilize mesoporous thin films that require a high crystallization temperature, with submonolayer quantity of an ALD material, and to apply mesoporous materials for high temperature applications. KW - Mesoporous oxides KW - Atomic layer deposition KW - Stabilization PY - 2018 DO - https://doi.org/10.1002/admi.201800360 VL - 5 IS - 14 SP - 1800360-1 EP - 1800360-9 PB - Wiley-VCH AN - OPUS4-47869 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wirth, Thomas T1 - Investigation of Silica Nanoparticles by Auger Electron Spectroscopy (AES) T2 - PHI European User Meeting 2014 CY - Ismaning, Germany DA - 2014-05-14 PY - 2014 AN - OPUS4-32947 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Graf, Nora A1 - Yegen, E. A1 - Lippitz, Andreas A1 - Treu, Dieter A1 - Wirth, Thomas A1 - Unger, Wolfgang T1 - Optimization of cleaning and aminosilanization protocols for Si wafers to be used as platforms for biochip microarrays by surface analysis (XPS, ToF-SIMS and NEXAFS spectroscopy) N2 - It is known that aminosilanized Si wafers may be used as microarray platforms. Results of an XPS study of a cleaning applied to Si wafers prior to aminosilanization are presented and discussed. Furthermore, the results of an aminosilanization protocol optimized in terms of nitrogen chemistry are described. After optimization of the protocol a free amine content of 94% was reached. The surface chemistry was investigated in this study by using XPS, time of flight (ToF)-SIMS and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. Reference to aminosilanization protocols reported in the literature has been made. KW - Aminosilanization KW - Si wafers KW - Microarray KW - XPS KW - ToF-SIMS KW - NEXAFS PY - 2008 DO - https://doi.org/10.1002/sia.2621 SN - 0142-2421 SN - 1096-9918 VL - 40 IS - 3-4 SP - 180 EP - 183 PB - Wiley CY - Chichester AN - OPUS4-17192 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Senoner, Mathias A1 - Wirth, Thomas A1 - Unger, Wolfgang T1 - Imaging surface analysis: Lateral resolution and its relation to contrast and noise N2 - Lateral resolution, also called image resolution, is the most relevant quality parameter of maps and line scans. Therefore well defined procedures for the determination of lateral resolution are required. In the surface analysis community different definitions of lateral resolution are in use and there is no generally accepted method for the determination of lateral resolution which meets the demands of the state-of-the-art in surface analysis. We propose the determination of lateral resolution by imaging of well defined square-wave gratings with finely graded periods. This method enables the real time estimation of lateral resolution and the adjustment of instrument settings with respect to lateral resolution. The effect of noise and contrast on lateral resolution has been analysed by numerically simulated images of square-wave gratings. A new resolution criterion has been developed which is based on the dip-to-noise ratio and takes into account the sampling step width by introducing a "reduced noise". The contrast transfer function has been introduced and its relation to lateral resolution in the presence of noise was analysed. For that reason an "effective cut-off frequency" was defined which is the reciprocal of the lateral resolution. Normalized values of lateral resolution and their relation to signal-to-noise ratio and sampling step width were given for Gaussian and Lorentzian line spread functions. These values enable the calculation of experimental parameters which are necessary to get a required value of lateral resolution. Finally the successful application of the proposed approach to determine lateral resolution has been demonstrated by ToF-SIMS element mapping of the certified reference material BAM-L200. KW - Auflösungskriterium KW - BAM-L200 KW - Effektive cut-off Funktion KW - Laterale Auflösung KW - Kontrast KW - Kontrasttransferfunktion KW - Linienverwaschungsfunktion KW - Rauschen PY - 2010 DO - https://doi.org/10.1039/c004323k SN - 0267-9477 SN - 1364-5544 VL - 25 SP - 1440 EP - 1452 PB - Royal Society of Chemistry CY - London AN - OPUS4-21875 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Senoner, Mathias A1 - Wirth, Thomas A1 - Unger, Wolfgang A1 - Österle, Werner A1 - Kaiander, I. A1 - Sellin, R.L. A1 - Bimberg, D. T1 - BAM-L002 - A new type of certified reference material for length calibration and testing of lateral resolution in the nanometre range N2 - A new type of test sample for the determination of lateral resolution in surface analysis is presented. The certified reference material BAM-L002 Nanoscale strip pattern for length calibration and testing of lateral resolution is an embedded cross-section of epitaxially grown layers of AlxGa1-xAs and InxGa1-xAs on GaAs substrate. The surface of the sample provides a flat pattern with strip widths of 0.4-500 nm. The combination of gratings, isolated narrow strips and sharp edges of wide strips offers improved possibilities for the calibration of a length scale, the determination of lateral resolution and the optimization of instrument settings. The feasibility of the reference material for an analysis of lateral resolution is demonstrated for SIMS. PY - 2004 DO - https://doi.org/10.1002/sia.1936 SN - 0142-2421 SN - 1096-9918 VL - 36 SP - 1423 EP - 1426 PB - Wiley CY - Chichester AN - OPUS4-4696 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wirth, Thomas T1 - Development of GD-OES standard measurement procedures by using PVD and other referencecoating samples T2 - Expert-Meeting "Depth Profiling", EU Network "Analytical GDS" CY - Dresden, Germany DA - 1999-10-13 PY - 1999 AN - OPUS4-6055 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wirth, Thomas T1 - Standard-Messverfahren, Referenzmaterialien für die GD-OES, Aktivitäten der BAM T2 - 7. Deutsches Anwendertreffen "Analytische GDS" CY - Dresden, Germany DA - 2000-10-17 PY - 2000 AN - OPUS4-6122 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wirth, Thomas T1 - Development of reference materials for GD-OES, SNMS, AES and Electron Beam Microanalysis: First results of the VAMAS project, the EC project "MICROLITE" and new EC - "Expression of needs" T2 - EC Network "Analytical GDS": Expert meetings "reference materials for non-conducting and layered samples", Standard procedures; European standards CY - Berlin, Germany DA - 2000-05-03 PY - 2000 AN - OPUS4-6095 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wirth, Thomas T1 - Electron-probe MICROanalysis of LIghT Elements; Measurement Methods and Certified Reference Materials (MICROLITE) - Minutes of Progress Meeting: WP1.2 Production of carbide and nitride standards and WP1.4 Stability testing T2 - MICROLITE 7th Progress Meeting, EKO Stahl CY - Eisenhüttenstadt, Germany DA - 2001-10-17 PY - 2001 AN - OPUS4-6901 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wirth, Thomas T1 - Electron-probe MICROanalysis of LIghT Elements; Measurement Methods and Certified Reference Materials (MICROLITE) - Minutes of Progress Meeting: WP1.2 Production of carbide and nitride standards and WP1.4 Stability testing T2 - MICROLITE 6th Progress Meeting CY - Palmones, Spain DA - 2001-03-16 PY - 2001 AN - OPUS4-6902 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hantsche, Harald A1 - Golze, Manfred A1 - Zabinski, A. A1 - Eckardt, Jürgen A1 - Wirth, Thomas A1 - Schmidt, Dieter T1 - Auger microprobe-surface analysis of sub-mum nitrides and carbonitrides in steel PY - 1993 SN - 0937-0633 VL - 346 SP - 29 EP - 36 PB - Springer CY - Berlin AN - OPUS4-6903 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -