ASTM E1016-07(2020)
(Guide)Standard Guide for Literature Describing Properties of Electrostatic Electron Spectrometers
Standard Guide for Literature Describing Properties of Electrostatic Electron Spectrometers
SIGNIFICANCE AND USE
5.1 The analyst may use this document to obtain information on the properties of electron spectrometers and instrumental aspects associated with quantitative surface analysis.
SCOPE
1.1 The purpose of this guide is to familiarize the analyst with some of the relevant literature describing the physical properties of modern electrostatic electron spectrometers.
1.2 This guide is intended to apply to electron spectrometers generally used in Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS).
1.3 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E1016 − 07 (Reapproved 2020)
Standard Guide for
Literature Describing Properties of Electrostatic Electron
Spectrometers
This standard is issued under the fixed designation E1016; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Spectrometers and Some X-Ray Photoelectron Spectrom-
eters
1.1 The purpose of this guide is to familiarize the analyst
E2108 Practice for Calibration of the Electron Binding-
with some of the relevant literature describing the physical
Energy Scale of an X-Ray Photoelectron Spectrometer
properties of modern electrostatic electron spectrometers.
2.2 ISO Standards:
1.2 Thisguideisintendedtoapplytoelectronspectrometers
ISO 18516 Surface Chemical Analysis—Auger Electron
generally used in Auger electron spectroscopy (AES) and
Spectroscopy and X-Ray Photoelectron Spectrsocopy—
X-ray photoelectron spectroscopy (XPS).
Determination of Lateral Resolution
1.3 The values stated in inch-pound units are to be regarded
ISO 21270 Surface Chemical Analysis—X-Ray Photoelec-
as standard. No other units of measurement are included in this tron and Auger Electron Spectrometers—Linearity of
standard.
Intensity Scale
ISO 24236 Surface Chemical Analysis—Auger Electron
1.4 This standard does not purport to address all of the
Spectroscopy—Repeatability and Constancy of Intensity
safety concerns, if any, associated with its use. It is the
Scale
responsibility of the user of this standard to establish appro-
ISO 24237 Surface Chemical Analysis—X-Ray Photoelec-
priate safety, health, and environmental practices and deter-
tron Spectroscopy—Repeatability and Constancy of In-
mine the applicability of regulatory limitations prior to use.
tensity Scale
1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard-
3. Terminology
ization established in the Decision on Principles for the
3.1 For definitions of terms used in this guide, refer to
Development of International Standards, Guides and Recom-
Terminology E673.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
4. Summary of Guide
2. Referenced Documents
4.1 This guide serves as a resource for relevant literature
which describes the properties of electron spectrometers com-
2.1 ASTM Standards:
monly used in surface analysis.
E673 Terminology Relating to SurfaceAnalysis (Withdrawn
2012)
5. Significance and Use
E902 Practice for Checking the Operating Characteristics of
X-Ray Photoelectron Spectrometers (Withdrawn 2011)
5.1 The analyst may use this document to obtain informa-
E1217 Practice for Determination of the Specimen Area tion on the properties of electron spectrometers and instrumen-
Contributing to the Detected Signal in Auger Electron
tal aspects associated with quantitative surface analysis.
6. General Description of Electron Spectrometers
This guide is under the jurisdiction of ASTM Committee E42 on Surface
6.1 An electron spectrometer is typically used to measure
Analysis and is the direct responsibility of Subcommittee E42.03 on Auger Electron
the energy and angular distributions of electrons emitted from
Spectroscopy and X-Ray Photoelectron Spectroscopy.
Current edition approved Dec. 1, 2020. Published December 2020. Originally
a specimen, typically for energies in the range 0 to 2500 eV. In
ɛ1
approved in 1984. Last previous edition approved in 2012 as E1016 – 07 (2012) .
surface analysis applications, the analyzed electrons are pro-
DOI: 10.1520/E1016-07R20.
duced from the bombardment of a sample surface with
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. Available from International Organization for Standardization (ISO), ISO
The last approved version of this historical standard is referenced on Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier,
www.astm.org. Geneva, Switzerland, http://www.iso.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E1016 − 07 (2020)
electrons, photons or ions. The entire spectrometer instrument 6.7 Specimen Area Contributing to the Detect Signal—See
may include one or more of the following: (1) apertures to Practice E1217 for methods to determine the specimen area
define the specimen area and emission solid angle for the contributing to the detected signal inAuger electron spectrom-
electrons accepted for analysis; (2) an electrostatic or magnetic eters and some X-Ray photoelectron spectrometers.
lens system, or both; (3) an electrostatic (dispersing) analyzer;
6.8 Calibration Protocol—Recommendations have been
and (4) a detector. Methods to check the operating character-
published describing spectrometer calibration requirements
istics of X-ray photoelectron spectrometers are reported in
and the frequency with which AES and XPS spectrometers
Practice E902.
should be calibrated (15).
6.2 Intensity Scale Calibration and Spectrometer Transmis-
sion Function—Quantitative analysis requires the determina-
7. Literature
tion of the ability of the spectrometer to transmit electrons, and
7.1 Electrostatic Analyzers—Spectrometers commonly used
the resultant detector signal, throughout the spectrometer
on modern AES and XPS spectrometer instruments generally
instrument. This can be described by an overall electron
employ electrostatic deflection analyzers.Auger electron spec-
energy-dependent transmission function Q(E) and is given by
trometersoftenusecylindricalmirroranalyzer(CMA)designs,
the product (1, 2), as follows:
although concentric hemispherical analyzers (CHA) (also
Q E 5 H E ·T E ·D E ·F E , (1)
~ ! ~ ! ~ ! ~ ! ~ !
known as spherical deflection (or sector) analyzers) are also
where:
used.The CHAdesign is the most common analyzer employed
on modern XPS instruments, although double-pass CMA
H(E) = the effect of mechanical imperfections (such as
designs were also employed on earlier XPS instruments.
aberrations, fringing fields, etc.),
T(E) = electron-optical transmission function, Retardingfieldanalyzers(RFA)havehistoricalinterestinearly
D(E) = detector efficiency, and AESwork,butarenowcommonlyusedonlowenergyelectron
F(E) = efficiency of the counting systems.
diffraction apparatus.
Knowledge of this transmission function permits the cali- 7.1.1 Electrostatic Deflection Analyzers—A review of the
brationofthespectraintensityaxis (3).Adetailedreviewofthe general properties of deflection analyzers may be found in
experimental determination of the transmission function for review articles (16, 17). More detailed reviews are also
XPS (4) and AES (5) measurements has been published.
available where, in addition to the CMA and CHA designs,
plane mirror, spherical mirror, cylindrical sector, and toroidal
6.3 Energy Scale Calibration—Calibration of the energy
deflection analyzers are treated (18-20).As the width of typical
scales of AES and XPS instruments is required for (1)
Auger spectral features are several electron volts, the use of a
meaningful comparison of building-energy or kinetic-energy
CMA design in conventional AES has sufficed for routine
measurements from two or more instruments; (2) valid identi-
analysis, particularly for small area analysis where a compro-
fication of chemical state from such comparisons; (3) effective
mise between signal-to-noise and energy resolution is impor-
use of databases containing reported energy values; and (4)as
tant. These are commonly used at a resolution defined by the
a component of a laboratory quality system. Suitable photon
full-width at half-maximum of the spectrometer energy
energyvaluesforAlandMganodeX-raysourcesoftenusedin
resolution, ∆E, divided by the electron energy, E, of 0.25 to
XPS measurements are available (6) and reference binding
0.6 %. The ability to incorporate an electron source concentric
energy values for copper (Cu), gold (Au), and silver (Ag) have
with the CMAaxis has been extensively exploited in scanning-
been published (7). Reference kinetic-energy values for Cu,
electron microscope instruments to give Auger data as a
aluminium (Al), and Au are also available (8, 9). Binding
function of beam position (that is, images). However, analysis
energy scale calibration procedures have been described in the
of the Auger spectra from some compounds and surface
literature for XPS (10, 11) and kinetic energy scale calibrations
morphologies may be enhanced by the use of a CHA design
for AES (8, 12-14) measurements. Practice E2108 describes a
which can provide better energy resolution (but a lower
procedure for calibrating the binding energy scale of XPS
transmission)andsuperiorangularresolution.TheCHAdesign
instruments using Cu, Ag, and Au specimens.
is most frequently employed on XPS instruments where
6.4 Linearity of Intensity Scale—See ISO 21270 for meth-
spectral features generally have narrow energy widths of 1 eV
ods to evaluate linearity of the intensity scale ofAES and XPS
or less and higher angular resolution is desired for the detected
spectrometers.
electrons than is possible with a CMA. The relationship
6.5 Repeatability and Constancy of Intensity Scale—See
between the pass energy of various spectrometer designs and
ISO 24236 and ISO 24237 for methods to evaluate the repeat-
the potential between their electrodes is described in detail
ability and constancy of intensity scales of AES and XPs
(16).
spectrometers, respectively.
7.1.2 Retarding Field Analyzers—The use of a retarding
6.6 Lateral Resolution—See ISO 18516 for methods to
field analyzer (RFA), consisting of concentric, spherical-sector
determine the lateral resolution of AES and XPS spectrom- grids, is currently used most commonly on electron diffraction
eters.
instruments where the angular distribution of the detected
electrons is examined. See also a brief review of RFA designs
(16)andasubstantialreportonresolutionandsensitivityissues
The boldface numbers in parentheses refer to the list of references at the end of
this guide. (21).
E1016 − 07 (2020)
7.2 Apertures—The effects of the spectrometer entrance and resistivecoatingisplaced.Thecoatingisformulatedtoprovide
exit slits and apertures, their associated fringing fields, as well a substantial secondary electron yield upon primary electron
as the effect of the divergence of the incident electron trajec- impact.The multiplier has a potential placed upon it so that the
tories on analyzer performance, particularly energy resolution, secondaryelectronsareacceleratedtoadjacentcoatedsurfaces,
havealsobeenreviewed (16-20).Adetailedexaminationofthe
thus providing the electron multiplying effect. Multipliers are
effects of unwanted internal scattering in CHA and CMA available in various shapes for both analog and pulse counting
electron spectrometers has been reported in the literature
amplification modes of operation (31). Single-channel electron
(22-24). multipliers were common in early instruments, but multiple-
channel (“multichannel”) electron multipliers fabricated into
7.3 Lens Systems—Input lens systems are frequently em-
thin plates are now available for use in detectors. See a general
ployed in CHA (and cylindrical sector) designs to vary the
review of electron multipliers (32-34). The use of position-
surface analysis area (25) and to permit a convenient location
sensitive detectors, such as resistive anodes, as well as wedge
of the CHA so as to allow access of complementary surface
and strip anodes at the output of such electron multipliers, has
characterization techniques to the sample (26). The electro-
afforded the ability to also record the spatial (angular) charac-
staticlensdesignoftenconsistsofacoaxialseriesofelectrodes
teristics of the analyzed electrons and has thus permitted the
that define the analysis area on the sample surface and
determination of surface composition as a function of position
determines the electron trajectories at the input to the analyzer.
(“chemical maps”) in XPS instruments (20, 33). A delay-line
The lens system also determines the angular resolution and
detector has recently been developed for XPS (35). The
modifies the transmission characteristics of the spectrometer
detection efficiency of single channel multipliers as a function
system (1). Reviews of electrostatic lens systems incorporated
of incident energy, angle of incidence, as well as count rate
in surface analysis instruments have been published (16-20,
have been reported (34). In addition, the influence of the
27). Lens systems have also been introduced at the exit of
detector electronics and counting systems have also been
analyzers for photoelectron imaging (17, 28-30). Methods to
examined (36, 37).
determine the specimen area examined are described in Prac-
tice E1217.
8. Keywords
7.4 Detectors—Detection of the analyzed electrons is gen-
erallyaccomplishedthroughtheuseofanelectronmultiplierto 8.1 apertures; Auger electron spectroscopy; detectors; elec-
produce usable signals. Surface analysis instruments currently tron spectrometers; electrostatic analyzers; lens systems; X-ray
use a variety of multipliers, but most are glass upon which a photoelectron spectroscopy
REFERENCES
(1) Seah, M.P., and Smith, G.C., “Quantitative AES and XPS: Determi- (8) Seah, M.P., and Gilmore, I.S., “AES: Energy Calibration of Electron
nation of the Electron Spectrometer Transmission Function and Spectrometers, III General Calibration Rules.” Journal of ELectron
Detector Sensitivity Energy Dependencies for the Production of True Spectroscopy and Related Phenomena, Vol 83, 1997, pp. 197–208.
Electron Emission Spectra in AES and XPS,” Surface and Interface (9) Seah,M.P.,“AES:ebergyCalibrationofElectronSpectrometersIV:A
Analysis, Vol 15, 1990, pp. 751–766. re-evaluation of the Reference ENergies,: Journal of ELectron Spec-
(2) Smith, G.C., and Seah, M.P., “Standard Reference Spectra for XPS trsocopy anf Related Phenomena, Vol 97, 1998, pp. 235–241.
and AES: Their Derivation, Validation and Use,” Surface and Inter- (10) Seah, M.P., Gilmore, I.S., and Spencer, S.J., “XPS—Binding-Energy
face Analysis, Vol 16, 1990, pp. 144–148. Calibration of Electron Spectrometers—4:Assessment
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.