Summary of ISO/TC 201 International Standard ISO 18516:2019 Surface chemical analysis—Determination of lateral resolution and sharpness in beam‐based methods with a range from nanometres to micrometres and its implementation for imaging laboratory X‐ray photoelectron spectrometers (XPS)

Abstract

ISO 18516:2019 Surface chemical analysis—Determination of lateral resolution and sharpness in beam‐based methods with a range from nanometres to micrometres revises ISO 18516:2006 Surface chemical analysis—Auger electron spectroscopy and X‐ray photoelectron spectroscopy—Determination of lateral resolution. It implements three different methods delivering parameters useful to express the lateral resolution: (1) the straight edge method, (2) the narrow line method and (3) the grating method. The theoretical background of these methods is introduced in ISO/TR 19319:2013 Surface chemical analysis—Fundamental approaches to determination of lateral resolution and sharpness in beam‐based methods. The revised International Standard ISO 18516 delivers standardized procedures for the determination of the (1) effective lateral resolution by imaging of square‐wave gratings, the (2) lateral resolution expressed as the parameter D12–88 characterizing the steepness of the sigmoidal edge spread function (ESF) determined by imaging a straight edge and (3) the lateral resolution expressed as the full width of half maximum of the line spread function (LSF), wLSF, determined by imaging a narrow line. The last method also delivers information on the shape of the LSF, which characterizes an individual imaging instrument. Finally, the implementation of all three standardized methods in the field of imaging laboratory X‐ray photoelectron spectroscopy (XPS) is shortly presented. This part of the letter is based on the use of a new test sample developed at ETH Zurich, Switzerland. This test sample displays a micrometre scaled pattern motivated by the resolving power of recent imaging XPS instruments.

Evaluation of the thermal stability of TiW/Cu heterojunctions using a combined SXPS and HAXPES approach

“…The experimental resolution when using a pass energy of 70 eV was found to be 390 and 240 meV for the 1.6 and 5.9 keV photon energies, respectively, as determined from measuring one standard deviation either side of the Fermi edge of a gold polycrystalline foil (16/84% method). 37 The binding energy scale of core level spectra was calibrated to the HAXPES recorded Cu 2p 3=2 BE position measured at the TiW/Cu interface. SXPS elemental depth profiles across the copper metallization were conducted using a Kratos Axis Supra laboratory-based instrument (EPSRC National Facility for X-ray Photoelectron Spectroscopy, Harwell, UK).…”

Temperature-modulated solution-based synthesis of copper oxide nanostructures for glucose sensing

“…The energy resolution was 0.6 eV at 20 eV pass energy, determined by extracting the Fermi edge width from the measurement of a polycrystalline gold foil (Z99.95%, Alfa Aesar) using the 16/84% method. 38 A 400 mm elliptical spot size was used with the X-ray gun operating with a 12 kV cathode voltage and 6 mA current, and a flood gun operating at 100 mA emission current. Samples were mounted on the holder plate using conductive carbon tape.…”

The Surface Analysis Working Group at the Consultative Committee for Amount of Substance, Metrology in Chemistry and Biology: A successful initiative by Martin Seah

“…In ISO/TC 201, Martin was a busy and successful project leader and the first Chairman of its Subcommittee SC1 on Terminology in surface chemical analysis. Furthermore, he was often acting as a consultant for other project leaders, for an example, see Unger et al 2 One of his most prominent achievements as project initiator and leader in ISO/TC 201 was the elaboration of vocabulary standards for surface spectroscopies and scanning‐probe microscopy 3,4…”

“…In ISO/TC 201, Martin was a busy and successful project leader and the first Chairman of its Subcommittee SC1 on Terminology in surface chemical analysis. Furthermore, he was often acting as a consultant for other project leaders, for an example, see Unger et al 2 One of his most prominent achievements as project initiator and leader in ISO/TC 201 was the elaboration of vocabulary standards for surface spectroscopies and scanning-probe microscopy. 3,4 As an employee of the National Metrology Institute UK, the NPL, Martin was-no surprise-highly motivated to underpin analytical tools by the development of the respective metrology to make them quantitative and traceable.…”