TY - JOUR A1 - Seah, M.P. A1 - Spencer, S.J. A1 - Bensebaa, F. A1 - Vickridge, I. A1 - Danzebrink, H. A1 - Krumrey, M. A1 - Gross, Thomas A1 - Österle, Werner A1 - Wendler, E. A1 - Rheinländer, B. A1 - Azuma, Y. A1 - Kojima, I. A1 - Suzuki, N. A1 - Suzuki, M. A1 - Tanuma, S. A1 - Moon, D.W. A1 - Lee, H.J. A1 - Cho, H.M. A1 - Chen, H.Y. A1 - Wee, A. T. S. A1 - Osipowicz, T. A1 - Pan, J.S. A1 - Jordaan, W.A. A1 - Hauert, R. A1 - Klotz, U. A1 - van der Marel, C. A1 - Verheijen, M. A1 - Tamminga, Y. A1 - Jeynes, C. A1 - Bailey, P. A1 - Biswas, S. A1 - Falke, U. A1 - Nguyen, N.V. A1 - Chandler-Horowitz, D. A1 - Ehrstein, J.R. A1 - Muller, D. A1 - Dura, J.A. T1 - Critical review of the current status of thickness measurements for ultrathin SiO2 on Si - Part V: Results of a CCQM pilot study N2 - Results are reported from a pilot study under the Consultative Committee for Amount of Substance (CCQM) to compare measurements of and resolve any relevant measurement issues in, the amount of thermal SiO2 oxide on (100) and (111) orientation Si wafer substrates in the thickness range 1.5 - 8 nm. As a result of the invitation to participate in this activity, 45 sets of measurements have been made in different laboratories using 10 analytical methods: medium-energy ion scattering spectrometry (MEIS), nuclear reaction analysis (NRA), RBS, elastic backscattering spectrometry (EBS), XPS, SIMS, ellipsometry, grazing-incidence x-ray reflectrometry (GIXRR), neutron reflectometry and transmission electron microscopy (TEM). The measurements are made on separate sets of 10 carefully prepared samples, all of which have been characterised by a combination of ellipsometry and XPS using carefully established reference conditions and reference parameters. The results have been assessed against the National Physical Laboratory (NPL) data and all show excellent linearity. The remaining data sets correlate with the NPL data with average root-mean-square scatters of 0.15 nm, half being better than 0.1 nm and a few at or better than 0.05 nm. Each set of data allows a relative scaling constant and a zero thickness offset to be determined. Each method has an inherent zero thickness offset between 0 nm and 1 nm and it is these offsets, measured here for the first time, that have caused many problems in the past. There are three basic classes of offset: water and carbonadeous contamination equivalent to ~1 nm as seen by ellipsometry; adsorbed oxygen mainly from water at an equivalent thickness of 0.5 nm as seen by MEIS, NRA, RBS and possibly GIXRR; and no offset as seen by XPS using the Si 2p peaks. Each technique has a different uncertainty for the scaling constant and consistent results have been achieved. X-Ray photoelectron spectroscopy has large uncertainties for the scaling constant but a high precision and, critically, if used correctly, has zero offset. Thus, a combination of XPS and the other methods allows the XPS scaling constant to be determined with low uncertainty, traceable via the other methods. XPS laboratories returning results early were invited to test a new reference procedure. All showed very significant improvements. The reference attenuation lengths thus need scaling by 0.986 ± 0.009 (at an expansion factor of 2) deduced from the data for the other methods. Several other methods have small offsets and, to the extent that these can be shown to be constant or measurable, then these methods will also show low uncertainty. Recommendations are provided for parameters for XPS, MEIS, RBS and NRA to improve their accuracy. KW - Calibration KW - Ellipsometry KW - GIXRR KW - Interlaboratory study KW - MEIS KW - Neutron reflectometry KW - NRA KW - RBS KW - Silicon dioxide KW - SIMS KW - XPS PY - 2004 U6 - https://doi.org/10.1002/sia.1909 SN - 0142-2421 SN - 1096-9918 VL - 36 IS - 9 SP - 1269 EP - 1303 PB - Wiley CY - Chichester AN - OPUS4-5549 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kim, K.J. A1 - Unger, Wolfgang A1 - Kim, J.W. A1 - Moon, D.W. A1 - Gross, Thomas A1 - Hodoroaba, Vasile-Dan A1 - Schmidt, Dieter A1 - Wirth, Thomas A1 - Jordaan, W. A1 - van Staden, M. A1 - Prins, S. A1 - Zhang, L. A1 - Fujimoto, T. A1 - Song, X.P. A1 - Wang, H. T1 - Inter-laboratory comparison: quantitative surface analysis of thin Fe-Ni alloy films N2 - An international interlaboratory comparison of the measurement capabilities of four National Metrology Institutes (NMIs) and one Designated Institute (DI) in the determination of the chemical composition of thin Fe-Ni alloy films was conducted via a key comparison (K-67) of the Surface Analysis Working Group of the Consultative Committee for Amount of Substance. This comparison was made using XPS (four laboratories) and AES (one laboratory) measurements. The uncertainty budget of the measured chemical composition of a thin alloy film was dominated by the uncertainty of the certified composition of a reference specimen which had been determined by inductively coupled plasma mass spectrometry using the isotope dilution method. Pilot study P-98 showed that the quantification using relative sensitivity factors (RSFs) of Fe and Ni derived from an alloy reference sample results in much more accurate result in comparison to an approach using RSFs derived from pure Fe and Ni films. The individual expanded uncertainties of the participants in the K-67 comparison were found to be between 2.88 and 3.40 atomic %. The uncertainty of the key comparison reference value (KCRV) calculated from individual standard deviations and a coverage factor (k) of 2 was 1.23 atomic %. KW - Quantification KW - Fe-Ni alloy KW - Uncertainty KW - Key comparison KW - Traceability PY - 2012 U6 - https://doi.org/10.1002/sia.3795 SN - 0142-2421 SN - 1096-9918 VL - 44 IS - 2 SP - 192 EP - 199 PB - Wiley CY - Chichester AN - OPUS4-24505 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Seah, M.P. A1 - Spencer, S.J. A1 - Bensebaa, F. A1 - Vickridge, I. A1 - Danzebrink, H. A1 - Krumrey, M. A1 - Gross, Thomas A1 - Österle, Werner A1 - Wendler, E. A1 - Rheinländer, B. A1 - Azuma, Y. A1 - Kojima, I. A1 - Suzuki, N. A1 - Suzuki, M. A1 - Tanuma, S. A1 - Moon, D.W. A1 - Lee, H.J. A1 - Cho, H.M. A1 - Chen, H.Y. A1 - Wee, A. T. S. A1 - Osipowicz, T. A1 - Pan, J.S. A1 - Jordaan, W.A. A1 - Hauert, R. A1 - Klotz, U. A1 - van der Marel, C. A1 - Verheijen, M. A1 - Tamminga, Y. A1 - Jeynes, C. A1 - Bailey, P. A1 - Biswas, S. A1 - Falke, U. A1 - Nguyen, N.V. A1 - Chandler-Horowitz, D. A1 - Ehrstein, J.R. A1 - Muller, D. A1 - Dura, J.A. T1 - Ultra-thin SiO2 on Si, Part V: Results of a CCQM Pilot Study of Thickness Measurements KW - SiO2 KW - Thin films KW - Thickness KW - XPS KW - Ellipsometry KW - TEM PY - 2003 SN - 1473-2734 SP - 57 pages AN - OPUS4-4118 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Seah, M.P. A1 - Unger, Wolfgang A1 - Wang, H. A1 - Jordaan, W. A1 - Gross, Thomas A1 - Dura, J.A. A1 - Moon, D.W. A1 - Totarong, P. A1 - Krumrey, M. A1 - Hauert, R. A1 - Zhiqiang, M. T1 - Ultra-thin SiO2 on Si IX: absolute measurements of the amount of silicon oxide as a thickness of SiO2 on Si N2 - Results from a study conducted between National Metrology Institutes (NMIs) for the measurements of the absolute thicknesses of ultra-thin layers of SiO2 on Si are reported. These results are from a key comparison and associated pilot study under the auspices of the Consultative Committee for Amount of Substance. ´Amount of substance´ may be expressed in many ways, and here the measurand is the thickness of the silicon oxide layers with nominal thicknesses in the range 1.5-8 nm on Si substrates, expressed as the thickness of SiO2. Separate samples were provided to each institute in containers that limited the carbonaceous contamination to approximately < 0.3 nm. The SiO2 samples were of ultra-thin on (100) and (111) orientated wafers of Si. The measurements from the laboratories which participated in the study were conducted using ellipsometry, neutron reflectivity, X-ray photoelectron spectroscopy or X-ray reflectivity, guided by the protocol developed in an earlier pilot study. A very minor correction was made in the different samples that each laboratory received. Where appropriate, method offset values attributed to the effects of contaminations, from the earlier pilot study, were subtracted. Values for the key comparison reference values (agreed best values from a Consultative Committee study) and their associated uncertainties for these samples are then made from the weighted means and the expanded weighted standard deviations of the means of these data. These results show a dramatic improvement on previous comparisons, leading to 95% uncertainties in the range 0.09-0.27 nm, equivalent to 0.4-1.0 monolayers over the 1.5-8.0 nm nominal thickness range studied. If the sample-to-sample uncertainty is reduced from its maximum estimate to the most likely value, these uncertainties reduce to 0.05-0.25 nm or ~1.4% relative standard uncertainties. The best results achieve ~1% relative standard uncertainty. It is concluded that XPS has now been made fully traceable to the SI, for ultra-thin thermal SiO2 on Si layers, by calibration using wavelength methods in an approach that may be extended to other material systems. KW - Attenuation length KW - Calibration KW - Silicon dioxide KW - Thickness KW - Ultra-thin oxide PY - 2009 U6 - https://doi.org/10.1002/sia.3045 SN - 0142-2421 SN - 1096-9918 VL - 41 IS - 5 SP - 430 EP - 439 PB - Wiley CY - Chichester AN - OPUS4-19246 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kim, K.J. A1 - Kim, J.W. A1 - Moon, D.W. A1 - Wirth, Thomas A1 - Hodoroaba, Vasile-Dan A1 - Gross, Thomas A1 - Unger, Wolfgang A1 - Jordaan, W. A1 - Staden, M.v. A1 - Prins, S. A1 - Wang, H. A1 - Song, X. A1 - Zhang, L. A1 - Fujimoto, T. A1 - Kojima, I. T1 - Final report on key comparison K67 and parallel pilot study P108: measurement of composition of a thin Fe-Ni alloy film N2 - The Key Comparison K67 and the parallel Pilot Study P108 on quantitative analysis of thin alloy films have been completed in the Surface Analysis Working Group (SAWG) of the Consultative Committee for Amount of Substance (CCQM). The aim of these inter-laboratory comparisons is to determine the degree of equivalence in the measurement capability of national metrology institutes (NMIs) and designated institutes (DIs) for the determination of the composition of thin alloy films. The measurand is expressed in atomic percent. A Fe-Ni alloy film with a certified composition was available for the participants of the inter-laboratory comparison. It has been used as a reference specimen to determine the relative sensitivity factors (RSF) of Fe and Ni for the different analytical methods used by the participants to determine the composition of the test sample. As was shown in the preceding Pilot Study P98, the degrees of equivalence in the measurement capabilities of the participants can be improved in that way. The composition of the reference specimen was certified by inductively coupled plasma mass spectrometry (ICP-MS) using the isotope dilution method. The in-depth and lateral homogeneity, determined in terms of elemental composition, of the certified reference sample and the unknown test sample were confirmed by secondary ion mass spectrometry (SIMS) using C60 primary ions by the leading laboratory. Five laboratories participated in the key comparison. Four of them used x-ray photoelectron spectroscopy (XPS) and one Auger electron spectroscopy (AES). One laboratory participated in the parallel P108 pilot study using electron probe micro analysis with an energy-dispersive spectrometer (ED EPMA) and XPS. KW - XPS KW - AES KW - EDX KW - Fe-Ni alloy film KW - Key comparison KW - CCQM PY - 2010 U6 - https://doi.org/10.1088/0026-1394/47/1A/08011 SN - 0026-1394 SN - 1681-7575 VL - 47 IS - 1A SP - 08011-1 - 08011-15 PB - Inst. of Physics Publ. CY - Bristol AN - OPUS4-21045 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kim, K.J. A1 - Kim, C.S. A1 - Ruh, S. W. A1 - Unger, Wolfgang A1 - Radnik, Jörg A1 - Mata-Salazar, J. A1 - Juarez-Garcia, J.M. A1 - Cortazar-Martinez, O. A1 - Herrera-Gomez, A. A1 - Hansen, P.E. A1 - Madesen, J.S. A1 - Senna, C.A. A1 - Archanjo, B.S. A1 - Damasceno, J.C. A1 - Achete, C.A. A1 - Wang, H. A1 - Wang, M. A1 - Windover, D. A1 - Steel, E. A1 - Kurokawa, A. A1 - Fujimoto, T. A1 - Azuma, Y. A1 - Terauchi, S. A1 - Zhang, L. A1 - Jordaan, W.A. A1 - Spencer, S.J. A1 - Shard, A.G. A1 - Koenders, L. A1 - Krumrey, M. A1 - Busch, I. A1 - Jeynes, C. T1 - Thickness measurement of nm HfO2 films N2 - A pilot study for the thickness measurement of HfO2 films was performed by the Surface Analysis Working Group (SAWG) of the Consultative Committee for Amount of Substance (CCQM). The aim of this pilot study was to ensure the equivalency in the measurement capability of national metrology institutes for the thickness measurement of HfO2 films. In this pilot study, the thicknesses of six HfO2 films with nominal thickness from 1 nm to 4 nm were measured by X-ray Photoelectron Spectroscopy (XPS), X-ray Reflectometry(XRR), X-ray Fluorescence Analysis (XRF), Transmission Electron Spectroscopy (TEM), Spectroscopic Ellipsometry (SE) and Rutherford Backscattering Spectrometry (RBS). The reference thicknesses were determined by mutual calibration of a zero-offset method (Medium Energy Ion Scattering Spectroscopy (MEIS) of KRISS) and a method traceable to the length unit (the average thicknesses of three XRR data except the thinnest film). These reference thicknesses are traceable to the length unit because they are based on the traceability of XRR. For the thickness measurement by XPS, the effective attenuation length of Hf 4f electrons was determined. In the cases of XRR and TEM, the offset values were determined from a linear fitting between the reference thicknesses and the individual data by XRR and TEM. The amount of substance of HfO2, expressed as thickness of HfO2 films (in both linear and areal density units), was found to be a good subject for a CCQM key comparison. To reach the main text of this paper, click on Final Report. The final report has been peer-reviewed and approved for publication by the CCQM. KW - Thickness measurements KW - nm films KW - X-ray Photoelectron Spectroscopy KW - Mutual calibration PY - 2021 U6 - https://doi.org/10.1088/0026-1394/58/1A/08016 SN - 0026-1394 VL - 58 IS - 1a SP - 08016 PB - IOP Publishing Lt. CY - Bristol AN - OPUS4-54175 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kim, K.J. A1 - Jang, J. S. A1 - Kim, A. S. A1 - Suh, J.K. A1 - Chung, Y.-D. A1 - Hodoroaba, Vasile-Dan A1 - Wirth, Thomas A1 - Unger, Wolfgang A1 - Kang, H. J. A1 - Popov, O. A1 - Popov, I. A1 - Kuselman, I. A1 - Lee, Y. H. A1 - Sykes, D. E. A1 - Wang, M. A1 - Wang, H. A1 - Ogiwara, T. A1 - Nishio, M. A1 - Tanuma, S. A1 - Simons, D. A1 - Szakal, C. A1 - Osborn, W. A1 - Terauchi, S. A1 - Ito, M. A1 - Kurokawa, A. A1 - Fujiimoto, T. A1 - Jordaan, W. A1 - Jeong, C. S. A1 - Havelund, R. A1 - Spencer, S. A1 - Shard, A. A1 - Streeck, C. A1 - Beckhoff, B. A1 - Eicke, A. A1 - Terborg, R. T1 - CCQM pilot study P-140: Quantitative surface analysis of multi-element alloy films N2 - A pilot study for the quantitative surface analysis of multi-element alloy films has been performed by the Surface Analysis Working Group (SAWG) of the Consultative Committee for Amount of Substance (CCQM). The aim of this pilot study is to ensure the equivalency in the measurement capability of national metrology institutes for the quantification of multi-element alloy films. A Cu(In,Ga)Se2 (CIGS) film with non-uniform depth distribution was chosen as a representative multi-element alloy film. The atomic fractions of the reference and the test CIGS films were certified by isotope dilution - inductively coupled plasma/mass spectrometry. A total number counting (TNC) method was used as a method to determine the signal intensities of the constituent elements, which are compared with their certified atomic fractions. The atomic fractions of the CIGS films were measured by various methods, such as Secondary Ion Mass Spectrometry (SIMS), Auger Electron Spectroscopy (AES), X-ray Photoelectron Spectroscopy (XPS), X-Ray Fluorescence (XRF) analysis and Electron Probe Micro Analysis (EPMA) with Energy Dispersive X-ray Spectrometry (EDX). Fifteen laboratories from eight National Metrology Institutes (NMIs), one Designated Institute (DI) and six non-NMIs participated in this pilot study. Although the average atomic fractions of 18 data sets showed rather poor relative standard deviations of about 5.5 % to 6.8 %, they were greatly improved to about 1.5 % to 2.2 % by excluding 5 strongly deviating data sets from the average atomic fractions. In this pilot study, the average expanded uncertainties of SIMS, XPS, AES, XRF and EPMA were 3.84%, 3.68%, 3.81%, 2.88% and 2.90%, respectively. These values are much better than those in the key comparison K-67 for composition of a Fe-Ni alloy film. As a result, the quantification of CIGS films using the TNC method was found to be a good candidate as a subject for a CCQM key comparison. KW - CCQM KW - Pilot study KW - Surface analysis KW - Alloy films KW - CIGS PY - 2015 U6 - https://doi.org/10.1088/0026-1394/52/1A/08017 SN - 0026-1394 SN - 1681-7575 VL - 52 IS - Technical Supplement SP - Article 08017 PB - Inst. of Physics Publ. CY - Bristol AN - OPUS4-35306 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -