ASTM E986-04(2017)
(Practice)Standard Practice for Scanning Electron Microscope Beam Size Characterization
Standard Practice for Scanning Electron Microscope Beam Size Characterization
SIGNIFICANCE AND USE
4.1 The traditional resolution test of the SEM requires, as a first step, a photomicrograph of a fine particulate sample taken at a high magnification. The operator is required to measure a distance on the photomicrograph between two adjacent, but separate edges. These edges are usually less than one millimetre apart. Their image quality is often less than optimum limited by the S/N ratio of a beam with such a small diameter and low current. Operator judgment is dependent on the individual acuity of the person making the measurement and can vary significantly.
4.2 Use of this practice results in SEM electron beam size characterization which is significantly more reproducible than the traditional resolution test using a fine particulate sample.
SCOPE
1.1 This practice provides a reproducible means by which one aspect of the performance of a scanning electron microscope (SEM) may be characterized. The resolution of an SEM depends on many factors, some of which are electron beam voltage and current, lens aberrations, contrast in the specimen, and operator-instrument-material interaction. However, the resolution for any set of conditions is limited by the size of the electron beam. This size can be quantified through the measurement of an effective apparent edge sharpness for a number of materials, two of which are suggested. This practice requires an SEM with the capability to perform line-scan traces, for example, Y-deflection waveform generation, for the suggested materials. The range of SEM magnification at which this practice is of utility is from 1000 to 50 000 × . Higher magnifications may be attempted, but difficulty in making precise measurements can be expected.
1.2 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 and health practices and determine the applicability of regulatory limitations prior to use.
1.3 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.
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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: E986 − 04 (Reapproved 2017)
Standard Practice for
Scanning Electron Microscope Beam Size Characterization
This standard is issued under the fixed designation E986; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 This practice provides a reproducible means by which 3.1 Definitions: For definitions of terms used in this
one aspect of the performance of a scanning electron micro- practice, see Terminology E7.
scope (SEM) may be characterized. The resolution of an SEM
3.2 Definitions of Terms Specific to This Standard:
depends on many factors, some of which are electron beam
3.2.1 Y-deflection waveform—the trace on a CRT resulting
voltage and current, lens aberrations, contrast in the specimen,
from modulating the CRT with the output of the electron
and operator-instrument-material interaction. However, the
detector. Contrast in the electron signal is displayed as a
resolution for any set of conditions is limited by the size of the
changein Y(vertical)ratherthanbrightnessonthescreen.This
electron beam. This size can be quantified through the mea-
operating method is often called Y-modulation.
surement of an effective apparent edge sharpness for a number
ofmaterials,twoofwhicharesuggested.Thispracticerequires 4. Significance and Use
an SEM with the capability to perform line-scan traces, for
4.1 The traditional resolution test of the SEM requires, as a
example, Y-deflection waveform generation, for the suggested
first step, a photomicrograph of a fine particulate sample taken
materials. The range of SEM magnification at which this
at a high magnification. The operator is required to measure a
practice is of utility is from 1000 to 50000×. Higher
distance on the photomicrograph between two adjacent, but
magnifications may be attempted, but difficulty in making
separate edges. These edges are usually less than one millime-
precise measurements can be expected.
tre apart. Their image quality is often less than optimum
1.2 This standard does not purport to address all of the
limited by the S/N ratio of a beam with such a small diameter
safety concerns, if any, associated with its use. It is the
and low current. Operator judgment is dependent on the
responsibility of the user of this standard to establish appro-
individual acuity of the person making the measurement and
priate safety and health practices and determine the applica-
can vary significantly.
bility of regulatory limitations prior to use.
4.2 Use of this practice results in SEM electron beam size
1.3 This international standard was developed in accor-
characterization which is significantly more reproducible than
dance with internationally recognized principles on standard-
the traditional resolution test using a fine particulate sample.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
5. Suggested Materials
mendations issued by the World Trade Organization Technical
5.1 SEM resolution performance as measured using the
Barriers to Trade (TBT) Committee.
procedurespecifiedinthispracticewilldependonthematerial
used; hence, only comparisons using the same material have
2. Referenced Documents
meaning. There are a number of criteria for a suitable material
2.1 ASTM Standards:
to be used in this practice. Through an evaluation of these
E7Terminology Relating to Metallography
criteria, two samples have been suggested. These samples are
E766Practice for Calibrating the Magnification of a Scan-
nonmagnetic; no surface preparation or coating is required;
ning Electron Microscope
thus, the samples have long-term structural stability. The
sample-electron beam interaction should produce a sharply
rising signal without inflections as the beam scans across the
This practice is under the jurisdiction of ASTM Committee E04 on Metallog-
raphy and is the direct responsibility of Subcommittee E04.11 on X-Ray and
edge. Two such samples are:
Electron Metallography. 3
5.1.1 Carbon fibers, NIST—SRM 2069B.
Current edition approved June 1, 2017. Published June 2017. Originally
5.1.2 Fracture edge of a thin silicon wafer, cleaved on a
approvedin1984.Lastpreviouseditionapprovedin2010asE986–04(2010).DOI:
10.1520/E0986-04R17. (111) plane.
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 Available from National Institute of Standards and Technology (NIST), 100
the ASTM website. Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http://www.nist.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E986 − 04 (2017)
6. Procedure
6.1 Inspect the specimen for cleanliness. If the specimen
appears contaminated, a new sample is recommended as any
cleaningmayadverselyaffectthequalityofthespecimenedge.
6.2 Ensure good electrical contact with the specimen by
using a conductive cement to hold the specimen on a SEM
stub, or by clamping the specimen on the stage of the SEM.
MountthespecimenrigidlyintheSEMtominimizeanyimage
degradation caused by vibration.
6.3 Verify magnification calibration for both X and Y direc-
tions. This can be accomplished by using Practice E766.
−2 −4
6.4 Use a clean vacuum of 1.33 by 10 Pa (10 mm Hg)
or better to minimize specimen contamination resulting from
electron beam and residual hydrocarbons interacting during
examination. The presence of a contamination layer has a
deleterious effect on image-edge quality.
6.5 Allow a minimum of 30 min for stabilization of elec-
tronic components, vacuum stability, and thermal equilibrium
fortheelectrongunandlenses.TheselectionofoptimumSEM
parameters is at the discretion of the operator. For measuring
the ultimate resolution, these will typically be: high kV
FIG. 1 Edge of Graphitized Natural Cellulose Fiber Used to Pro-
duce Line Traces (Fig. 3)
(~30max.), short working
...
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E986 − 04 (Reapproved 2017)
Standard Practice for
Scanning Electron Microscope Beam Size Characterization
This standard is issued under the fixed designation E986; 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 3. Terminology
1.1 This practice provides a reproducible means by which 3.1 Definitions: For definitions of terms used in this
one aspect of the performance of a scanning electron micro- practice, see Terminology E7.
scope (SEM) may be characterized. The resolution of an SEM
3.2 Definitions of Terms Specific to This Standard:
depends on many factors, some of which are electron beam
3.2.1 Y-deflection waveform—the trace on a CRT resulting
voltage and current, lens aberrations, contrast in the specimen,
from modulating the CRT with the output of the electron
and operator-instrument-material interaction. However, the
detector. Contrast in the electron signal is displayed as a
resolution for any set of conditions is limited by the size of the
change in Y (vertical) rather than brightness on the screen. This
electron beam. This size can be quantified through the mea-
operating method is often called Y-modulation.
surement of an effective apparent edge sharpness for a number
of materials, two of which are suggested. This practice requires
4. Significance and Use
an SEM with the capability to perform line-scan traces, for
4.1 The traditional resolution test of the SEM requires, as a
example, Y-deflection waveform generation, for the suggested
first step, a photomicrograph of a fine particulate sample taken
materials. The range of SEM magnification at which this
at a high magnification. The operator is required to measure a
practice is of utility is from 1000 to 50 000 × . Higher
distance on the photomicrograph between two adjacent, but
magnifications may be attempted, but difficulty in making
separate edges. These edges are usually less than one millime-
precise measurements can be expected.
tre apart. Their image quality is often less than optimum
1.2 This standard does not purport to address all of the
limited by the S/N ratio of a beam with such a small diameter
safety concerns, if any, associated with its use. It is the
and low current. Operator judgment is dependent on the
responsibility of the user of this standard to establish appro-
individual acuity of the person making the measurement and
priate safety and health practices and determine the applica-
can vary significantly.
bility of regulatory limitations prior to use.
4.2 Use of this practice results in SEM electron beam size
1.3 This international standard was developed in accor-
characterization which is significantly more reproducible than
dance with internationally recognized principles on standard-
the traditional resolution test using a fine particulate sample.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
5. Suggested Materials
mendations issued by the World Trade Organization Technical
5.1 SEM resolution performance as measured using the
Barriers to Trade (TBT) Committee.
procedure specified in this practice will depend on the material
used; hence, only comparisons using the same material have
2. Referenced Documents
meaning. There are a number of criteria for a suitable material
2.1 ASTM Standards:
to be used in this practice. Through an evaluation of these
E7 Terminology Relating to Metallography
criteria, two samples have been suggested. These samples are
E766 Practice for Calibrating the Magnification of a Scan-
nonmagnetic; no surface preparation or coating is required;
ning Electron Microscope
thus, the samples have long-term structural stability. The
sample-electron beam interaction should produce a sharply
rising signal without inflections as the beam scans across the
This practice is under the jurisdiction of ASTM Committee E04 on Metallog-
raphy and is the direct responsibility of Subcommittee E04.11 on X-Ray and
edge. Two such samples are:
Electron Metallography.
5.1.1 Carbon fibers, NIST—SRM 2069B.
Current edition approved June 1, 2017. Published June 2017. Originally
5.1.2 Fracture edge of a thin silicon wafer, cleaved on a
approved in 1984. Last previous edition approved in 2010 as E986 – 04(2010). DOI:
(111) plane.
10.1520/E0986-04R17.
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 Available from National Institute of Standards and Technology (NIST), 100
the ASTM website. Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http://www.nist.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E986 − 04 (2017)
6. Procedure
6.1 Inspect the specimen for cleanliness. If the specimen
appears contaminated, a new sample is recommended as any
cleaning may adversely affect the quality of the specimen edge.
6.2 Ensure good electrical contact with the specimen by
using a conductive cement to hold the specimen on a SEM
stub, or by clamping the specimen on the stage of the SEM.
Mount the specimen rigidly in the SEM to minimize any image
degradation caused by vibration.
6.3 Verify magnification calibration for both X and Y direc-
tions. This can be accomplished by using Practice E766.
− 2 − 4
6.4 Use a clean vacuum of 1.33 by 10 Pa (10 mm Hg)
or better to minimize specimen contamination resulting from
electron beam and residual hydrocarbons interacting during
examination. The presence of a contamination layer has a
deleterious effect on image-edge quality.
6.5 Allow a minimum of 30 min for stabilization of elec-
tronic components, vacuum stability, and thermal equilibrium
for the electron gun and lenses. The selection of optimum SEM
parameters is at the discretion of the operator. For measuring
the ultimate resolution, these will typically be: high kV
FIG. 1 Edge of Graphitized Natural Cellulose Fiber Used to Pro-
duce Line Traces (Fig. 3)
(~30max.), short working distance (5 to 10 mm), smallest spot
size, and long scan time.
6.6 Any alternative set
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E986 − 04 (Reapproved 2010) E986 − 04 (Reapproved 2017)
Standard Practice for
Scanning Electron Microscope Beam Size Characterization
This standard is issued under the fixed designation E986; 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
1.1 This practice provides a reproducible means by which one aspect of the performance of a scanning electron microscope
(SEM) may be characterized. The resolution of an SEM depends on many factors, some of which are electron beam voltage and
current, lens aberrations, contrast in the specimen, and operator-instrument-material interaction. However, the resolution for any
set of conditions is limited by the size of the electron beam. This size can be quantified through the measurement of an effective
apparent edge sharpness for a number of materials, two of which are suggested. This practice requires an SEM with the capability
to perform line-scan traces, for example, Y-deflection waveform generation, for the suggested materials. The range of SEM
magnification at which this practice is of utility is from 1000 to 50 000 × . Higher magnifications may be attempted, but difficulty
in making precise measurements can be expected.
1.2 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 and health practices and determine the applicability of regulatory
limitations prior to use.
1.3 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.
2. Referenced Documents
2.1 ASTM Standards:
E7 Terminology Relating to Metallography
E766 Practice for Calibrating the Magnification of a Scanning Electron Microscope
3. Terminology
3.1 Definitions: For definitions of terms used in this practice, see Terminology E7.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 Y-deflection waveform—the trace on a CRT resulting from modulating the CRT with the output of the electron detector.
Contrast in the electron signal is displayed as a change in Y (vertical) rather than brightness on the screen. This operating method
is often called Y-modulation.
4. Significance and Use
4.1 The traditional resolution test of the SEM requires, as a first step, a photomicrograph of a fine particulate sample taken at
a high magnification. The operator is required to measure a distance on the photomicrograph between two adjacent, but separate
edges. These edges are usually less than one millimetre apart. Their image quality is often less than optimum limited by the S/N
ratio of a beam with such a small diameter and low current. Operator judgment is dependent on the individual acuity of the person
making the measurement and can vary significantly.
4.2 Use of this practice results in SEM electron beam size characterization which is significantly more reproducible than the
traditional resolution test using a fine particulate sample.
This practice is under the jurisdiction of ASTM Committee E04 on Metallography and is the direct responsibility of Subcommittee E04.11 on X-Ray and Electron
Metallography.
Current edition approved April 1, 2010June 1, 2017. Published May 2010 June 2017. Originally approved in 1984. Last previous edition approved in 20042010 as
E986 – 04.E986 – 04(2010). DOI: 10.1520/E0986-04R10.10.1520/E0986-04R17.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E986 − 04 (2017)
5. Suggested Materials
5.1 SEM resolution performance as measured using the procedure specified in this practice will depend on the material used;
hence, only comparisons using the same material have meaning. There are a number of criteria for a suitable material to be used
in this practice. Through an evaluation of these criteria, two samples have been suggested. These samples are nonmagnetic; no
surface preparation or coating is required; thus, the samples have long-term structural stability. The sample-electron beam
interaction should produce a sharply rising signal without inflections as the beam scans across the edge. Two such samples are:
5.1.1 Carbon fibers, NIST—SRM 2069B.
5.1.2 Fracture edge of a thin silicon wafer, cleaved on a (111) plane.
6. Procedure
6.1 Inspect the specimen for cleanliness. If the specimen appears contaminated, a new sample is recommended as any cleaning
may adversely affect the quality of the specimen edge.
6.2 Ensure good electrical contact with the specimen by using a conductive cement to hold the specimen on a SEM stub, or by
clamping the specimen on the stage of the SEM. Mount the specimen rigidly in the SEM to minimize any image degradation
caused by vibration.
6.3 Verify magnification calibration for both X and Y directions. This can be accomplished by using Practice E766.
− 2 − 4
6.4 Use a clean vacuum of 1.33 by 10 Pa (10 mm Hg) or better to minimize specimen contamination resulting from electron
beam and residual hydrocarbons interacting during examination. The presence of a contamination layer has a deleterious effect on
image-edge quality.
6.5 Allow a minimum of 30 min for stabilization of electronic components, vacuum stability, and thermal equilibrium for the
electron gun and lenses. The selection of optimum SEM parameters is at the discretion of the operator. For measuring the ultimate
resolution, these will typically be: high kV (~30max.), short working distance (5 to 10 mm), smallest spot size, and long scan time.
6.6 Any alternative set of conditions can be used to measure probe size, but they will measure beam diameter under those
specific
...
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