ASTM F1372-93(2005)
(Test Method)Standard Test Method for Scanning Electron Microscope (SEM) Analysis of Metallic Surface Condition for Gas Distribution System Components
Standard Test Method for Scanning Electron Microscope (SEM) Analysis of Metallic Surface Condition for Gas Distribution System Components
SIGNIFICANCE AND USE
The purpose of this test method is to define a procedure for testing components being considered for installation into a high-purity gas distribution system. Application of this test method is expected to yield comparable data among components tested for purposes of qualification for this installation.
SCOPE
1.1 This test method covers the testing of interior surfaces of components such as tubing, fittings, and valves for surface morphology.
1.2 This test method applies to all surfaces of tubing, connectors, regulators, valves, and any metal component, regardless of size.
1.3 Limitations:
1.3.1 This methodology assumes a SEM operator skill level typically achieved over a 12-month period.
1.3.2 This test method shall be limited to the assessment of pits, stringer, tears, grooves, scratches, inclusions, stepped grain boundaries, and other surface anomalies. However, stains and particles that may be produced during specimen preparation should be excluded in the assessment of anomalies.
1.4 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only.
1.5 This standard does not purport to address all of the safety problems, 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. Specific hazard statements are given in Section 6.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: F1372 − 93(Reapproved 2005)
Standard Test Method for
Scanning Electron Microscope (SEM) Analysis of Metallic
Surface Condition for Gas Distribution System
Components
This standard is issued under the fixed designation F1372; 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.
INTRODUCTION
Semiconductor clean rooms are serviced by high-purity gas distribution systems. This test method
presentsaprocedurethatmaybeappliedfortheevaluationofoneormorecomponentsconsideredfor
use in such systems.
1. Scope 2. Referenced Documents
1.1 This test method covers the testing of interior surfaces
2.1 NIST Standards:
of components such as tubing, fittings, and valves for surface
SRM 484 F SEM Magnification Standard
morphology.
SRM 20690 SEM Performance Standard
1.2 This test method applies to all surfaces of tubing,
3. Terminology
connectors, regulators, valves, and any metal component,
3.1 Definitions:
regardless of size.
3.1.1 defect—a pit, scratch, groove, inclusion, stringer,
1.3 Limitations:
stepped grain boundary, crack, or other surface feature that is
1.3.1 This methodology assumes a SEM operator skill level
either characteristic of the material or a result of its processing
typically achieved over a 12-month period.
that is not a result of the sample preparation.
1.3.2 This test method shall be limited to the assessment of
3.1.2 grid size—the grid size (length of the x- and y-axis
pits, stringer, tears, grooves, scratches, inclusions, stepped
grid dimension) will be 1.814 µm multiplied by the magnifi-
grainboundaries,andothersurfaceanomalies.However,stains
cation of the photomicrograph. For example, for a standard 4
and particles that may be produced during specimen prepara-
by 5-in. photographic image at 3500 × magnification, the grid
tion should be excluded in the assessment of anomalies.
would be 0.635 by 0.635 cm (0.25 by 0.25 in.).
1.4 The values stated in SI units are to be regarded as the
3.1.3 groove—a two-dimensional defect on the surface that
standard. The inch-pound units given in parentheses are for
has depth and width.
information only.
3.1.3.1 Discussion—For this kind of defect, the depth is
1.5 This standard does not purport to address all of the
greater than the width, or, conversely, the width is greater than
safety concerns, if any, associated with its use. It is the
the depth.
responsibility of the user of this standard to establish appro-
3.1.4 inclusion—particlesofaforeignmaterialinametallic
priate safety and health practices and determine the applica-
matrix (see Fig. 1).
bility of regulatory limitations prior to use. Specific hazard
3.1.4.1 Discussion—These particles are usually compounds
statements are given in Section 6.
(such as oxides, nitrides, carbo-nitrides, sulfides, or silicates),
but may be of any substance (and is essentially insoluble in the
This test method is under the jurisdiction of ASTM Committee F01 on
metal matrix).
Electronics and is the direct responsibility of Subcommittee F01.10 on Contamina-
tion Control.
Current edition published Jan. 1, 2005. Approved Jan. 1, 2005. Originally
approved in 1992. Last previous edition approved in 1999 as F1372 – 93(1999). Available from National Institute of Standards and Technology, Gaithersburg,
DOI: 10.1520/F1372-93R05. MD 20899.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F1372 − 93 (2005)
3.1.10 standard conditions—101.3 kPa, 0.0°C (14.73 psia,
32.0°F).
3.1.11 stepped grain boundary—a grain boundary that has
been etched to form a sudden change in height between
adjacent grains.
3.1.12 stringer—in wrought materials, an elongated con-
figuration of microconstituents or inclusions aligned in the
direction of working (see Fig. 3).
3.1.12.1 Discussion—In electropolished stainless steel
(SST), the stringer defect may have inclusion material on it, or
thematerialmayhavebeenremovedduringelectropolishingor
cleaning, leaving an elongated void.
3.1.13 working distance—the distance between the bottom
of the objective lens and the sample.
4. Significance and Use
4.1 The purpose of this test method is to define a procedure
FIG. 1 Example of Inclusion (3600 × magnification)
for testing components being considered for installation into a
high-purity gas distribution system. Application of this test
method is expected to yield comparable data among compo-
3.1.5 number of anomalies—the total number of defects per
nents tested for purposes of qualification for this installation.
photomicrograph (see 10.1.1).
5. Apparatus
3.1.6 particles that loosely adhere—particles in which over
⁄4 of the bulk of the particle is above the plane of the surface.
5.1 Materials:
3.1.6.1 Discussion—These particles generally appear very
5.1.1 Mounting Stubs, specific to the instrument used are
bright, and little detail of the surface of the particle is seen
required.
when the contrast and brightness are adjusted to image the
5.1.2 Adhesives, must be vacuum stable, to attach samples
sample surface.
to sample stubs.Any adhesive that provides a conductive path
is acceptable.
3.1.7 pit—a small, sharp, roughly circular cavity in the
5.1.3 Photomicrosamples, must include the following infor-
metal surface (see Fig. 2).
mation through the use of electronic notation on the SEM
3.1.8 sample angle—that angle measured normal to the
screen or ink on the back of the photomicrograph: sample
incoming electron beam.
identification, magnification, and date.
3.1.9 scratch— a one-dimensional defect on the surface
5.1.4 Scale Marker, (calibration bar) must be present and
such as a line on the surface.
clearly visible on all photographs.
3.1.9.1 Discussion—For this type of defect, the depth of the
5.2 Instrumentation:
defect is no deeper than the width of the defect.
FIG. 2 Example of Pit Defect (3600 × magnification) FIG. 3 Example of Stringer (3600 × magnification)
F1372 − 93 (2005)
5.2.1 Scanning Electron Microscope (SEM)— The SEM 9.4 Move the sample until an area of interest on the
used for this study should have a minimum point-to-point sample’s surface comes into focus. Make sure that the area of
resolution of 30 nm as measured with NIST Standard SRM interest is represen
...
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