1、Designation: E1078 14Standard Guide forSpecimen Preparation and Mounting in Surface Analysis1This standard is issued under the fixed designation E1078; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A nu
2、mber in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers specimen preparation and mountingprior to, during, and following surface analysis and applies tothe following surface a
3、nalysis disciplines:1.1.1 Auger electron spectroscopy (AES),1.1.2 X-ray photoelectron spectroscopy (XPS and ESCA),and1.1.3 Secondary ion mass spectrometry (SIMS).1.1.4 Although primarily written for AES, XPS, and SIMS,these methods will also apply to many surface sensitiveanalysis methods, such as i
4、on scattering spectrometry, lowenergy electron diffraction, and electron energy lossspectroscopy, where specimen handling can influence surfacesensitive measurements.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This s
5、tandard 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 determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.
6、1 ASTM Standards:2E983 Guide for Minimizing Unwanted Electron Beam Ef-fects in Auger Electron SpectroscopyE1127 Guide for Depth Profiling in Auger Electron Spec-troscopyE1523 Guide to Charge Control and Charge ReferencingTechniques in X-Ray Photoelectron SpectroscopyE1829 Guide for Handling Specimen
7、s Prior to SurfaceAnalysis2.2 ISO Standards:3ISO 181151 Surface chemical analysisVocabularyPart1: General terms and terms used in spectroscopyISO 181152 Surface chemical analysisVocabularyPart2: Terms used in scanning-probe microscopy3. Terminology3.1 DefinitionsFor definitions of surface analysis t
8、ermsused in this guide, see ISO 18115-1 and ISO 18115-2.4. Significance and Use4.1 Proper preparation and mounting of specimens is par-ticularly critical for surface analysis. Improper preparation ofspecimens can result in alteration of the surface compositionand unreliable data. Specimens should be
9、 handled carefully soas to avoid the introduction of spurious contaminants in thepreparation and mounting process. The goal must be topreserve the state of the surface so that the analysis remainsrepresentative of the original.4.2 AES, XPS or ESCA, and SIMS are sensitive to surfacelayers that are ty
10、pically a few nanometres thick. Such thinlayers can be subject to severe perturbations caused byspecimen handling (1)4or surface treatments that may benecessary prior to introduction into the analytical chamber. Inaddition, specimen mounting techniques have the potential toaffect the intended analys
11、is.4.3 This guide describes methods that the surface analystmay need to minimize the effects of specimen preparationwhen using any surface-sensitive analytical technique. Alsodescribed are methods to mount specimens so as to ensure thatthe desired information is not compromised.4.4 Guide E1829 descr
12、ibes the handling of surface sensitivespecimens and, as such, complements this guide.5. General Requirements5.1 Although the handling techniques for AES, XPS, andSIMS are basically similar, there are some differences. Ingeneral, preparation of specimens for AES and SIMS requires1This guide is under
13、the jurisdiction of ASTM Committee E42 on SurfaceAnalysis and is the direct responsibility of Subcommittee E42.03 on Auger ElectronSpectroscopy and X-Ray Photoelectron Spectroscopy.Current edition approved Oct. 1, 2014. Published November 2014. Originallyapproved in 1990. Last previous edition appro
14、ved in 2009 as E1078 09. DOI:10.1520/E1078-14.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from
15、 International Organization for Standardization (ISO), 1, ch. dela Voie-Creuse, CP 56, CH-1211 Geneva 20, Switzerland, http:/www.iso.org.4The boldface numbers in parentheses refer to a list of references at the end ofthis standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, Wes
16、t Conshohocken, PA 19428-2959. United States1more attention because of potential problems with electron orion beam damage or charging, or both. This guide will notewhen specimen preparation is significantly different among thethree techniques.5.2 The degree of cleanliness required by surface sensiti
17、veanalytical techniques is often much greater than for other formsof analysis.5.3 Specimens and mounts must never be in contact with thebare hand. Handling of the surface to be analyzed should beeliminated or minimized whenever possible. Fingerprints con-tain mobile species that may contaminate the
18、surface ofinterest. Hand creams, skin oils, and other skin materials arenot suitable for high vacuum.5.4 Visual Inspection:5.4.1 A visual inspection should be made, possibly using anoptical microscope, prior to analysis. At a minimum, a checkshould be made for residues, particles, fingerprints, adhe
19、sives,contaminants, or other foreign matter.5.4.2 Features that are visually apparent outside the vacuumsystem may not be observable with the systems usual imagingmethod or through available viewports. It may be necessary tophysically mark the specimen outside the area to be analyzed(for example, wi
20、th scratches or a permanent ink marker) so thatthe analysis location can be found once the specimen is insidethe vacuum system.5.4.3 Changes that may occur during analysis may influencethe data interpretation. Following analysis, visual examinationof the specimen is recommended to look for possible
21、effects ofsputtering, electron beam exposure, X-ray exposure, orvacuum.6. Specimen Influences6.1 HistoryThe history of a specimen may affect thehandling of the surface before analysis. For example, aspecimen that has been exposed to a contaminating environ-ment may reduce the need for exceptional ca
22、re if the surfacebecomes less reactive. Alternatively, the need for care mayincrease if the surface becomes toxic.6.1.1 If a specimen is known to be contaminated, preclean-ing may be warranted in order to expose the surface of interestand reduce the risk of vacuum system contamination. Ifprecleaning
23、 is desired, a suitable grade solvent should be usedthat does not affect the specimen material (electronic gradesolvents if appropriate or available are best suited). Note thateven high purity solvents may leave residues on a surface.Cleaning may also be accomplished using an appropriatelyfiltered p
24、ressurized gas. In some instances, the contaminationitself may be of interest, for example, where a silicone releaseagent influences adhesion. In these cases, no precleaningshould be attempted.6.1.2 Special caution must be taken with specimens con-taining potential toxins.6.2 Information SoughtThe i
25、nformation sought can influ-ence the preparation of a specimen. If the information soughtcomes from the exterior surface of a specimen, greater care andprecautions in specimen preparation must be taken than if theinformation sought lies beneath an overlayer that must besputtered away in the analytic
26、al chamber. Furthermore, it mayalso be possible to expose the layer of interest by in-situfracture, cleaving, or other means.6.3 Specimens Previously Examined by Other AnalyticalTechniquesIt is best if surface analysis measurements aremade before the specimen is analyzed by other analyticaltechnique
27、s because such specimens may become damaged ormay be exposed to surface contamination. For example,insulating specimens analyzed by electron microscopy mayhave been coated to reduce charging. This coating will renderthe specimen unsuitable for subsequent surface analysis.Furthermore, exposure to an
28、electron beam (for example, in aSEM) can induce damage or cause the adsorption and deposi-tion of species from the residual vacuum. If it is not possible toperform surface analysis first, then the analysis should be doneon a different, but nominally identical, specimen or area of thespecimen.7. Sour
29、ces of Specimen Contamination7.1 Tools, Gloves, Etc.:7.1.1 Preparation and mounting of specimens should onlybe done with clean tools to ensure that the specimen surface isnot altered prior to analysis and that the best possible vacuumconditions are maintained in the analytical chamber. Tools usedto
30、handle specimens should be made of materials that will nottransfer to the specimen or introduce spurious contaminants(for example, nickel tools contaminate silicon). Tools shouldbe cleaned in high purity solvents and dried prior to use.Nonmagnetic tools should be used if the specimen is suscep-tible
31、 to magnetic fields. Tools should never unnecessarily touchthe specimen surface.7.1.2 Although gloves and wiping materials are sometimesused to prepare specimens, it is likely that their use may resultin some contamination. Care should be taken to avoid con-tamination by talc, silicone compounds, an
32、d other materialsthat are often found on gloves. “Powder-free” gloves have notalc and may be better suited. Unnecessary contact with theglove or other tool shall be avoided.7.1.3 Specimen mounts and other materials used to holdspecimens should be cleaned regularly whenever there is apossibility of c
33、ross-contamination of specimens. Avoid the useof tapes containing silicones and other mobile species.7.2 Particulate DebrisBlowing ones breath on the speci-men is likely to cause contamination. Compressed gases fromaerosol cans or from air lines are often used to blow particlesfrom the surface or to
34、 attempt to clean a specimen. They, too,must be considered a source of possible contamination. Whileparticles are removed from specimens by these methods,caution is advised and the methods should be avoided incritical cases. In particular, oil is often a contaminant incompressed air lines. In-line p
35、article filters can reduce oil andparticles from these sources. A gas stream can also producestatic charge in many specimens, and this could result inattraction of more particulate debris. Use of an ionizing nozzleon the gas stream may eliminate this problem.7.3 Vacuum Conditions and TimeSpecimens t
36、hat were inequilibrium with the ambient environment prior to insertionE1078 142into the vacuum chamber may desorb surface species, such aswater vapor, plasticizers, and other volatile components. Thismay cause cross-contamination of adjacent samples and mayincrease the chamber pressure. It also may
37、cause changes insurface chemistry of the specimens of interest.7.4 Effects of the Incident Flux:7.4.1 The incident electron flux in AES, ion flux in SIMS,and, to a lesser extent, the photon flux in XPS, may inducechanges in the specimen being analyzed (2), for example bycausing enhanced reactions be
38、tween the surface of a specimenand the residual gases in the analytical chamber. The incidentflux also may locally heat or degrade the specimen, or both,resulting in a change of surface chemistry or a possible rise inchamber pressure and in contamination of the analyticalchamber. These effects are d
39、iscussed in Guide E983.7.4.2 Residual gases or the incident beam may alter thesurface. One can test for undesirable effects by monitoringsignals from the specimen as a function of time, for example bysetting up the system for a sputter depth profile and then notturning on the ion gun. If changes wit
40、h time are observed, thenthe interpretation of the results must account for the observa-tion of an altered surface. This method may also detectdesorption of surface species. Care should be taken to accountfor the possible effects of incident beam fluctuation.7.4.3 The incident ion beams used during
41、SIMS, AES, andXPS depth profiles not only erode the surface of interest butcan also affect surfaces nearby. This can be caused by poorfocusing of the primary ion beam and impact of neutrals fromthe primary beam. These adjacent areas may not be suitable forsubsequent analysis by surface analysis meth
42、ods. In somecases, sputtered material may be deposited onto adjacent areason the specimen or onto other specimens that may be in theanalytical chamber.7.5 Analytical Chamber Contamination:7.5.1 The analyst should be alert to materials that will leadto contamination of the vacuum chamber as well as o
43、therspecimens in the chamber. High vapor pressure elements suchas mercury, tellurium, cesium, potassium, sodium, arsenic,iodine, zinc, selenium, phosphorus, sulfur, etc. should beanalyzed with caution. Many other materials also can exhibithigh vapor pressures; these include some polymers, foams, and
44、other porous materials, greases and oils, and liquids.7.5.2 Even if an unperturbed specimen meets the vacuumrequirements of the analytical chamber, the probing beamrequired for analysis may degrade the specimen and result inserious contamination, as discussed in 7.4.1.7.5.3 Contamination by surface
45、diffusion can be a problem,especially with silicone compounds (3) and hydrocarbons. It ispossible to have excellent vacuum conditions in the analyticalchamber and still find contamination by surface diffusion.7.5.4 In SIMS, atoms sputtered onto the secondary ionextraction lens or other nearby surfac
46、es can be resputtered backonto the surface of the specimen. This effect can be reduced bynot having the secondary ion extraction lens or other surfacesclose to the specimen. The use of multiple immersion lensstrips or cleaning of the lens can help reduce this effect.7.5.5 The order of use of probing
47、 beams can be important,especially when dealing with organic material or other fragilematerials (such as those discussed in Section 12).8. Specimen Storage and Transfer8.1 Storage:8.1.1 TimeThe longer a specimen is in storage, the morecare must be taken to ensure that the surface to be analyzed hasn
48、ot been contaminated. Even in clean laboratory environments,surfaces can quickly become contaminated to the depth ana-lyzed by AES, XPS, SIMS, and other surface sensitive analyti-cal techniques.8.1.2 Containers:8.1.2.1 Containers suitable for storage should not transfercontaminants to the specimen b
49、y means of particles, liquids,gases, or surface diffusion. Keep in mind unsuitable containersmay contain volatile species, such as plasticizers, that may beemitted, contaminating the surface. Preferably, the surface tobe analyzed should not contact the container or any otherobject. Glass jars with an inside diameter slightly larger thanthe width of a specimen can hold a specimen without contactwith the surface. When contact with the surface is unavoidable,wrapping in clean, pre-analyzed aluminum foil may be satis-factory. Containers with a beveled bottom may also be
