ISO 17973:2024

International
Standard
ISO 17973
Third edition
Surface chemical analysis —
Medium-resolution Auger electron
spectrometers — Calibration of
energy scales for elemental analysis
Analyse chimique des surfaces — Spectromètres d'électrons
Auger à résolution moyenne — Étalonnage des échelles d'énergie
pour l'analyse élémentaire
PROOF/ÉPREUVE
Reference number
© ISO 2024
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
PROOF/ÉPREUVE
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms. 1
5 Outline of method . 2
6 Energy scale calibration procedures . 3
6.1 Obtaining reference samples .3
6.2 Mounting samples .3
6.3 Cleaning samples .3
6.4 Choosing spectrometer settings for energy calibration .5
6.5 Operating the instrument .5
6.6 Measurement of reference peaks .6
6.7 Determining measured kinetic energies of reference peaks .7
6.8 Determining correction of instrument kinetic energy scale .8
6.9 Next calibration .9
Bibliography .11
PROOF/ÉPREUVE
iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
The committee responsible for this document is Technical Committee ISO/TC 201, Surface chemical analysis,
Subcommittee SC 7, Electron spectroscopies.
This third edition cancels and replaces the second edition (ISO 17973:2016), which has been technically
revised.
The main changes are as follows:
— NOTE added to 6.3 to provide example sputtering conditions for cleaning sample surface;
— text added to 6.5 regarding need to check detector is operating within its linear region.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
PROOF/ÉPREUVE
iv
Introduction
Auger electron spectroscopy (AES) is used extensively for the surface analysis of materials. Elements in the
sample (with the exception of hydrogen and helium) are identified from comparisons of the peak energies and
peak shapes, with tabulations of peak energies and data in handbooks of spectra for the different elements.
To identify the peaks, calibration of the energy scale with an uncertainty of 3 eV is generally adequate, and
this document is only intended for work at that level of accuracy (for greater accuracy, see ISO 17974).
The method for calibrating kinetic energy scales specified in this document uses metallic samples of pure
copper (Cu) and either aluminium (Al) or gold (Au). It does not include tests for defects in the instrument,
since few defects are significant at the level of accuracy concerned.
Traditionally, kinetic energies of Auger electrons have been referenced to the vacuum level, and this reference
is still used by many analysts. However, the vacuum level is ill-defined and can vary from instrument to
instrument over a range of 0,5 eV. Although use of the vacuum level reference procedure will generally not
cause ambiguity in elemental identification, it can cause uncertainty in measurements at high resolution
relating to chemical states. Because of this, instruments designed for both Auger electron spectroscopy and
X-ray photoelectron spectroscopy reference the kinetic energies to the Fermi level, giving values typically
4,5 eV higher than those referenced to the vacuum level. For the purposes of this document, the user is free
to choose the reference appropriate to their work.
PROOF/ÉPREUVE
v
International Standard ISO 17973:2024(en)
Surface chemical analysis — Medium-resolution Auger
electron spectrometers — Calibration of energy scales for
elemental analysis
1 Scope
This document specifies a method for calibrating the kinetic energy scales of Auger electron spectrometers
with an uncertainty of 3 eV, for general analytical use in identifying elements at surfaces. This document
also specifies a method for establishing a calibration schedule.
It is applicable to instruments used in either direct or differential mode, where the resolution is less than
or equal to 0,5 % and the modulation amplitude for the differential mode, if used, is 2 eV peak-to-peak. It is
applicable to those spectrometers equipped with an inert gas ion gun or other method for sample cleaning
and with an electron gun capable of operating at 4 keV or higher beam energy.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 18115 (all parts), Surface chemical analysis — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in the ISO 18115 series apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Symbols and abbreviated terms
AES Auger electron spectroscopy
a measured energy scaling error
b measured zero offset error, in eV
E corrected result for kinetic energy corresponding to given E , in eV
corr meas
E measured kinetic energy, in eV
meas
E measured kinetic energy for peak n (see Table 1), in eV
meas,n
E reference values for kinetic energy position of peak n (see Table 1), in eV
ref,n
FWHM full width at half maximum peak intensity above background, in eV
PROOF/ÉPREUVE
W FWHM of peak
Δ offset energy, given by average measured kinetic energy for calibration peak minus reference
n
kinetic energy, in eV, for n = 1, 2, 3, 4 (see Table 1)
ΔE correction added to E after calibration to provide corrected kinetic energy result
corr meas
β energy scale scan rate for analogue systems, in eV/s
τ time constant for analogue detector electronics, in s
5 Outline of method
Calibration of an Auger electron spectrometer using this document is performed by obtaining and preparing
copper and gold or aluminium reference foils in order to measure the kinetic energies of selected Auger
electron peaks. These reference materials are chosen as they provide one Auger electron peak in the
high energy range, one in the middle range and one at low energies. The samples are cleaned and spectra
are recorded in the direct mode, if that is available, or in the differential mode if not. The energies of the
peaks are compared with reference values to provide an energy scale correction. How this correction is
implemented depends on the facilities available with the spectrometer. Because this calibration can alter
with time, a procedure is defined to enable the calibration to be established at regular intervals.
See Figure 1 for a flowchart showing the general structure of the work and the sequence of procedures.
NOTE The numbers refer to the corresponding subclauses in this document.
Figure 1 — Flowchart of method — Sequence of procedures
PROOF/ÉPREUVE
6 Energy scale calibration procedures
6.1 Obtaining reference samples
For the calibration of Auger electron spectrometers providing a high signal-to-noise ratio, as defined below,
and able to scan the kinetic energy range up to 2 100 eV, use samples of Cu and Au. For spectrometers with a
lower signal-to-noise ratio or those only able to scan to 2 000 eV, use samples of Cu and Al.
If, for the spectrometer used, the counts for the Cu L VV peak in the direct mode are less than 400 000 counts
per channel, or the root mean square noise in the differential spectrum exceeds 0,3 % of the Cu L VV peak-
to-peak signal, or if the maximum electron beam energy is less than 5 keV, Cu and Al may be used instead of
Cu and Au, since the recording of suitable Au data can be time consuming.
For instruments with higher signal intensities and for spectrometers able to scan to 2 100 eV, the use of Au
can be found to be the more convenient and able to provide a calibration over a wider energy range. The
requirement for 400 000 counts per channel for the Cu L VV peak may be relaxed to 100 000 counts per
[2]
channel if Savitzky and Golay smoothing is available at nine or more points in the smooth .
All samples shall be polycrystalline and of at least 99,8 % purity metals which, for convenience, are usually
in the form of foils typically of an area 10 mm by 10 mm, and from 0,1
...

ISO/DISPRF 17973:2023(E)
ISO/TC 201/SC 7
Secretariat: BSI
2023-09-25
Surface chemical analysis — Medium-resolution Auger electron
spectrometers — Calibration of energy scales for elemental analysis
Analyse chimique des surfaces — Spectromètres d'électrons Auger à résolution moyenne — Étalonnage des
échelles d'énergie pour l'analyse élémentaire
PROOF
ISO/DISPRF 17973:2023(E2024(en)
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication
may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying,
or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO
at the address below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
Fax: +41 22 749 09 47
EmailE-mail: copyright@iso.org
Website: www.iso.orgwww.iso.org
Published in Switzerland
ii © ISO 2023 – All rights reserved
ii
ISO/DISPRF 17973:2023(E2024(en)
Contents Page
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 1
5 Outline of method . 2
6 Energy scale calibration procedures . 4
6.1 Obtaining reference samples . 4
6.2 Mounting samples . 5
6.3 Cleaning samples . 5
6.4 Choosing spectrometer settings for energy calibration . 9
6.5 Operating the instrument . 9
6.6 Measurement of reference peaks . 9
6.7 Determining measured kinetic energies of reference peaks . 12
6.8 Determining correction of instrument kinetic energy scale . 13
6.9 Next calibration . 15
Bibliography . 16

Foreword . iv
Introduction . v
1 Scope . 1
2 Normative reference . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 1
5 Outline of method . 2
6 Energy scale calibration procedures . 3
6.1 Obtaining reference samples . 3
6.2 Mounting samples . 3
6.3 Cleaning samples . 3
6.4 Choosing spectrometer settings for energy calibration . 5
6.5 Operating the instrument . 5
6.6 Measurement of reference peaks . 6
6.7 Determining the measured kinetic energies of the reference peaks . 8
6.8 Determination of the correction of the instrument kinetic energy scale . 8
6.9 Next calibration . 9
Bibliography . 11
iii
ISO/DISPRF 17973:2023(E2024(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of
ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s)
which may be required to implement this document. However, implementers are cautioned that this may not
represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents.www.iso.org/patents. ISO shall not be held responsible for identifying any or all such
patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.htmlwww.iso.org/iso/foreword.html.
The committee responsible for this document is Technical Committee ISO/TC 201, Surface chemical analysis,
Subcommittee SC 7, Electron spectroscopies.
This third edition cancels and replaces the second edition (ISO 17973:2016), which has been technically
revised.
The main changes are as follows:
A note has been— NOTE added to Clause 6.36.3 to provide an example of the sputtering conditions that are
usually found satisfactory for cleaning thesample surface of a sample.;
A paragraph has been— text added to Clause 6.5 to warn the analyst that it may be necessary6.5 regarding
need to check that the detector is operating within its linear region.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv © ISO 2023 – All rights reserved
iv
ISO/DISPRF 17973:2023(E2024(en)
Introduction
Auger electron spectroscopy (AES) is used extensively for the surface analysis of materials. Elements in the
sample (with the exception of hydrogen and helium) are identified from comparisons of the peak energies and
peak shapes, with tabulations of peak energies and data in handbooks of spectra for the different elements. To
identify the peaks, calibration of the energy scale with an uncertainty of 3 eV is generally adequate, and this
document is only intended for work at that level of accuracy (for greater accuracy, see ISO 17974).
The method for calibrating kinetic energy scales specified in this document uses metallic samples of pure
copper (Cu) and either aluminium (Al) or gold (Au). It does not include tests for defects in the instrument,
since few defects are significant at the level of accuracy concerned.
Traditionally, kinetic energies of Auger electrons have been referenced to the vacuum level, and this reference
is still used by many analysts. However, the vacuum level is ill-defined and can vary from instrument to
instrument over a range of 0,5 eV. Although use of the vacuum level reference procedure will generally not
cause ambiguity in elemental identification, it can cause uncertainty in measurements at high resolution
relating to chemical states. Because of this, instruments designed for both Auger electron spectroscopy and X-
ray photoelectron spectroscopy reference the kinetic energies to the Fermi level, giving values typically 4,5 eV
higher than those referenced to the vacuum level. For the purposes of this document, the user is free to choose
the reference appropriate to their work.
v
DRAFT INTERNATIONAL STANDARD ISO/DIS 17973:2023(E)

Surface chemical analysis — Medium-resolution Auger electron
spectrometers — Calibration of energy scales for elemental analysis
1 Scope
This document specifies a method for calibrating the kinetic energy scales of Auger electron spectrometers
with an uncertainty of 3 eV, for general analytical use in identifying elements at surfaces. This document also
specifies a method for establishing a calibration schedule.
It is applicable to instruments used in either direct or differential mode, where the resolution is less than or
equal to 0,5 % and the modulation amplitude for the differential mode, if used, is 2 eV peak-to-peak. It is
applicable to those spectrometers equipped with an inert gas ion gun or other method for sample cleaning
and with an electron gun capable of operating at 4 keV or higher beam energy.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 18115 (all parts), Surface chemical analysis — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in the ISO 18115 series apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— — ISO Online browsing platform: available at https://www.iso.org/obphttps://www.iso.org/obp
— — IEC Electropedia: available at https://www.electropedia.org/https://www.electropedia.org/
4 Symbols and abbreviated terms
AES Auger electron spectroscopy
a measured energy scaling error
b measured zero offset error, in eV
E corrected result for kinetic energy corresponding to given E , in eV
corr meas
E measured kinetic energy, in eV
meas
E measured kinetic energy for peak n (see Table 1),Table 1), in eV
meas,n
E reference values for kinetic energy position of peak n (see Table 1),Table 1), in eV
ref,n
FWHM full width at half maximum peak intensity above background, in eV
W FWHM of peak
ISO/DISPRF 17973:2023(E2024(en)
Δ offset energy, given by average measured kinetic energy for calibration peak minus reference
n
kinetic energy, in eV, for n = 1, 2, 3, 4 (see Table 1)Table 1)
ΔE correction added to E after calibration to provide corrected kinetic energy result
corr meas
β energy scale scan rate for analogue systems, in eV/s
τ time constant for analogue detector electronics, in s
5 Outline of method
Calibration of an Auger electron spectrometer using this document is performed by obtaining and preparing
copper and gold or aluminium reference foils in order to measure the kinetic energies
...