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Static SIMS–VAMAS interlaboratory study for intensity repeatability, mass scale accuracy and relative quantification
Author(s) -
Green F. M.,
Gilmore I. S.,
Lee J. L. S.,
Spencer S. J.,
Seah M. P.
Publication year - 2010
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.3181
Subject(s) - repeatability , calibration , wafer , analytical chemistry (journal) , reproducibility , mass spectrometry , standard deviation , materials science , chemistry , chromatography , nanotechnology , statistics , mathematics
An interlaboratory study involving 19 time‐of‐flight static secondary ion mass spectrometer (TOF‐SSIMS) instruments from 12 countries has been conducted. Analysts were supplied, by the National Physical Laboratory, with a protocol for analysis together with three reference materials: poly(tetrafluoroethylene), a thin layer of polycarbonate on a silicon wafer and a patterned sample with different amounts of Irganox 1010 in each of four quadrants on a silicon wafer. The objectives of the study are (i) to determine the repeatability and constancy of the relative intensity scale achievable using the draft ISO standard (DIS 23830), (ii) to evaluate the effectiveness of mass scale calibration and optimisation procedure and (iii) to evaluate the current capability of relative quantification using SSIMS. The results of this study show that the constancy of the relative intensity scale has an approximate scatter standard deviation of only 5%. This is excellent and demonstrates that SSIMS measurements are significantly more stable than often thought by analysts. The draft ISO standard (DIS) CD 13084 for calibration of the mass scale in TOF‐SIMS was evaluated and found to be consistent with our previous study. Four laboratories optimised the instrument mass calibration accuracy using this procedure leading to improvements in mass scale calibration by factors of 1.8, 2.2, 2.3 and 8.6. Using a novel patterned Irganox sample it is shown that the precision of relative quantification may be as good as a standard deviation of only 5% for 16 instruments—this is a remarkable result. Further work is required to develop more robust reference materials. © Crown copyright 2010. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.