1、Designation: F1372 93 (Reapproved 2012)Standard Test Method forScanning Electron Microscope (SEM) Analysis of MetallicSurface Condition for Gas Distribution SystemComponents1This standard is issued under the fixed designation F1372; the number immediately following the designation indicates the year
2、 oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.INTRODUCTIONSemiconductor clean rooms are serviced by high-purity ga
3、s distribution systems. This test methodpresents a procedure that may be applied for the evaluation of one or more components considered foruse in such systems.1. Scope1.1 This test method covers the testing of interior surfacesof components such as tubing, fittings, and valves for surfacemorphology
4、.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 leveltypically achieved over a 12-month period.1.3.2 This test method shall be limited to the assessm
5、ent ofpits, stringer, tears, grooves, scratches, inclusions, steppedgrain boundaries, and other surface anomalies. However, stainsand particles that may be produced during specimen prepara-tion should be excluded in the assessment of anomalies.1.4 The values stated in SI units are to be regarded as
6、thestandard. The inch-pound units given in parentheses are forinformation only.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and dete
7、rmine the applica-bility of regulatory limitations prior to use. Specific hazardstatements are given in Section 6.2. Referenced Documents2.1 NIST Standards:SRM 484 F SEM Magnification Standard2SRM 20690 SEM Performance Standard23. Terminology3.1 Definitions:3.1.1 defecta pit, scratch, groove, inclus
8、ion, stringer,stepped grain boundary, crack, or other surface feature that iseither characteristic of the material or a result of its processingthat is not a result of the sample preparation.3.1.2 grid sizethe grid size (length of the x- and y-axisgrid dimension) will be 1.814 m multiplied by the ma
9、gnifi-cation of the photomicrograph. For example, for a standard 4by 5-in. photographic image at 3500 magnification, the gridwould be 0.635 by 0.635 cm (0.25 by 0.25 in.).3.1.3 groovea two-dimensional defect on the surface thathas depth and width.3.1.3.1 DiscussionFor this kind of defect, the depth
10、isgreater than the width, or, conversely, the width is greater thanthe depth.3.1.4 inclusion particles of a foreign material in a metallicmatrix (see Fig. 1).3.1.4.1 DiscussionThese particles are usually compounds(such as oxides, nitrides, carbo-nitrides, sulfides, or silicates),but may be of any su
11、bstance (and is essentially insoluble in themetal matrix).1This test method is under the jurisdiction of ASTM Committee F01 onElectronics and is the direct responsibility of Subcommittee F01.10 on Contamina-tion Control.Current edition published July 1, 2012. Approved August 2012. Originallyapproved
12、 in 1992. Last previous edition approved in 2005 as F1372 93(2005).DOI: 10.1520/F1372-93R12.2Available from National Institute of Standards and Technology, Gaithersburg,MD 20899.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.5 nu
13、mber of anomaliesthe total number of defects perphotomicrograph (see 10.1.1).3.1.6 particles that loosely adhereparticles in which over34 of the bulk of the particle is above the plane of the surface.3.1.6.1 DiscussionThese particles generally appear verybright, and little detail of the surface of t
14、he particle is seenwhen the contrast and brightness are adjusted to image thesample surface.3.1.7 pita small, sharp, roughly circular cavity in themetal surface (see Fig. 2).3.1.8 sample anglethat angle measured normal to theincoming electron beam.3.1.9 scratch a one-dimensional defect on the surfac
15、esuch as a line on the surface.3.1.9.1 DiscussionFor this type of defect, the depth of thedefect is no deeper than the width of the defect.3.1.10 standard conditions101.3 kPa, 0.0C (14.73 psia,32.0F).3.1.11 stepped grain boundarya grain boundary that hasbeen etched to form a sudden change in height
16、betweenadjacent grains.3.1.12 stringerin wrought materials, an elongated con-figuration of microconstituents or inclusions aligned in thedirection of working (see Fig. 3).3.1.12.1 DiscussionIn electropolished stainless steel(SST), the stringer defect may have inclusion material on it, orthe material
17、 may have been removed during electropolishing orcleaning, leaving an elongated void.3.1.13 working distancethe distance between the bottomof the objective lens and the sample.4. Significance and Use4.1 The purpose of this test method is to define a procedurefor testing components being considered f
18、or installation into ahigh-purity gas distribution system. Application of this testmethod is expected to yield comparable data among compo-nents tested for purposes of qualification for this installation.5. Apparatus5.1 Materials:5.1.1 Mounting Stubs, specific to the instrument used arerequired.5.1.
19、2 Adhesives, must be vacuum stable, to attach samplesto sample stubs. Any adhesive that provides a conductive pathis acceptable.5.1.3 Photomicrosamples, must include the following infor-mation through the use of electronic notation on the SEMscreen or ink on the back of the photomicrograph: sampleid
20、entification, magnification, and date.5.1.4 Scale Marker, (calibration bar) must be present andclearly visible on all photographs.5.2 Instrumentation:FIG. 1 Example of Inclusion (3600 magnification)FIG. 2 Example of Pit Defect (3600 magnification) FIG. 3 Example of Stringer (3600 magnification)F1372
21、 93 (2012)25.2.1 Scanning Electron Microscope (SEM) The SEMused for this study should have a minimum point-to-pointresolution of 30 nm as measured with NIST Standard SRM20696 or equivalent. A high resolution commercially availableSEM with photographic capabilities is recommended. The hardcopy photom
22、icrographic medium from which the defect countis taken must have an area of 100 cm2.5.2.2 Instrument Operating Parameters , shall be as fol-lows: accelerating voltage, 20 KeV; working distance, 10 to 30mm; sample tilt, 0; and, final aperture size, 150 m or less.5.2.3 Magnification for quantitative p
23、ass/fail analysis shallbe five randomly chosen areas photographed at 3500 6 100.5.2.4 Instruments will be calibrated every 6 months andcalibration verified prior to starting a series of test methodmeasurements using standard laboratory practices and manu-facturers recommendations. Archive or supply
24、magnificationcalibration check with results.5.2.5 Setup and Schematic, to be furnished by instrumentmanufacturer.6. Hazards6.1 Observe all normal and acceptable precautions regard-ing use of high voltage, X-ray producing equipment.7. Sampling, Test Specimens, and Test Units7.1 Prepare the samples ac
25、cording to 9.1 of this test methodto expose the surface.7.2 Sample preparation shall not cause the temperature ofthe sample to exceed 90C (194F).7.3 Mount the samples onto SEM compatible mounts in amanner that avoids contamination of the surface to be ana-lyzed.7.4 Use adhesives, when necessary, in
26、a manner that doesnot contaminate the area of interest.7.5 Do not coat samples with a conductive thin layer (forexample, gold or carbon).8. Calibration8.1 Calibrate instruments regularly using standard labora-tory practices and manufacturers recommendations.9. Procedure9.1 Sample Cutting and Mountin
27、g :9.1.1 Use any mechanical cutting method that minimizesalteration of the surface. A clean, dry hacksaw is preferred.9.1.2 After cutting, clean samples in a reagent grade solventand rinse with a reagent grade isopropyl alcohol (IPA). Placesamples in a nitrogen-filled, resealable, non-outgassing con
28、-tainer.9.1.3 Mount samples on the instrument stub.9.2 Introduce the sample stub into the SEM vacuum cham-ber.9.3 Activate the electron beam when vacuum conditionsmeet those recommended by the manufacturer.9.4 Move the sample until an area of interest on thesamples surface comes into focus. Make sur
29、e that the area ofinterest is representative of the whole, avoiding gross defor-mities.9.5 Orient the sample to the degree that the longitudinal axisof the sample curvature, if applicable, is aligned with the axisof the secondary detector.9.6 Increase the magnification to 20 000 to 40 000 for finalf
30、ocus, correcting astigmatism, and other instrument anomaliesto yield a clear image.9.7 Decrease the magnification to 3500 6 100 and recordthe image on a photographic medium.9.8 Move to a second random area and repeat the proce-dures in 9.5 through 9.7 for four additional sample sites. Ifadditional a
31、nalyses are required, they may be performed at thistime, for example, energy dispersive X-ray spectrometer(EDX).9.9 Turn off the SEM electron beam and remove the samplefrom the vacuum chamber.10. Interpretation of Results10.1 Data Presentation:10.1.1 Overlay the recorded images with a scale as defin
32、edin 3.1.4. The grid line should be as fine as possible and stillremain clearly visible. The lower left corner of the grid is tocorrespond with the lower left corner of the photograph. Sumthe number of surface anomalies per square (such as pits,scratches, inclusions, and stringers) as the total per
33、micrograph.Defects that appear in one or more adjacent squares shall countas one defect for each square occupied by the defect. Particlesthat loosely adhere to the surface must be presumed to beartifacts from atmosphere or sample preparation techniques,etc, and therefore will be ignored.10.1.2 Prese
34、nt the data as photomicrographs (five from eachsample) and in tabular form, showing total number of particlescounted (per area analyzed) in the grid overlay. Photomicro-graphs must include the following information through the useof electronic notation on the SEM screen or ink on the back ofthe phot
35、omicrograph: sample identification, magnification, anddate. The data table shall include a summation of the totalcounts for all five micrographs with the average and themaximum count for any one micrograph.10.1.3 Use illustrations wherever confusion may exist re-garding the area of analysis or whene
36、ver multiple sites on onesample must be identified.10.1.4 The EDX spectra and corresponding photographsshould be appropriately labeled so that the elemental compo-sition of any specific defect, particle, or anomaly is readilyapparent to any third party.11. Report11.1 Report the following information
37、:11.1.1 EDX spectra and related photomicrographs mustinclude the following information: sample identification, date,peak identification, tilt angle, and voltage,11.1.2 All data reported must identify the SEM equipmentmanufacturer and model number, andF1372 93 (2012)311.1.3 Any special modifications
38、in equipment or procedurenecessary to acquire data must also be documented and fullydescribed.12. Precision and Bias12.1 Precision and bias for this test method are beingdetermined.13. Keywords13.1 components; contamination; gas distribution; metallicsurface condition; SEM analysis; semiconductor pr
39、ocessing;surface conditionASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infrin
40、gement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard
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42、 known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).F1372 93 (2012)4
