1、Designation: E 1078 09Standard Guide forSpecimen Preparation and Mounting in Surface Analysis1This standard is issued under the fixed designation E 1078; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、number 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
3、 analysis 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 a
4、s ion scattering spectrometry, lowenergy electron diffraction, and electron energy loss spectros-copy, where specimen handling can influence surface sensitivemeasurements.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 T
5、his 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 determine the applica-bility of regulatory limitations prior to use.2. Referenced Docume
6、nts2.1 ASTM Standards:2E 673 Terminology Relating to Surface AnalysisE 983 Guide for Minimizing Unwanted Electron BeamEffects in Auger Electron SpectroscopyE 1127 Guide for Depth Profiling in Auger Electron Spec-troscopyE 1829 Guide for Handling Specimens Prior to SurfaceAnalysisE 1523 Guide to Char
7、ge Control and Charge ReferencingTechniques in X-Ray Photoelectron Spectroscopy3. Terminology3.1 DefinitionsFor definitions of surface analysis termsused in this guide, see Terminology E 673.4. Significance and Use4.1 Proper preparation and mounting of specimens is par-ticularly critical for surface
8、 analysis. Improper preparation ofspecimens can result in alteration of the surface compositionand unreliable data. Specimens should be handled carefully soas to avoid the introduction of spurious contaminants in thepreparation and mounting process. The goal must be topreserve the state of the surfa
9、ce so that the analysis remainsrepresentative of the original.4.2 AES, XPS or ESCA, and SIMS are sensitive to surfacelayers that are typically a few nanometres thick. Such thinlayers can be subject to severe perturbations caused byspecimen handling (1)3or surface treatments that may benecessary prio
10、r to introduction into the analytical chamber. Inaddition, specimen mounting techniques have the potential toaffect the intended analysis.4.3 This guide describes methods that the surface analystmay need to minimize the effects of specimen preparationwhen using any surface-sensitive analytical techn
11、ique. Alsodescribed are methods to mount specimens so as to ensure thatthe desired information is not compromised.4.4 Guide E 1829 describes the handling of surface sensi-tive specimens and, as such, complements this guide.5. General Requirements5.1 Although the handling techniques for AES, XPS, and
12、SIMS are basically similar, there are some differences. Ingeneral, preparation of specimens for AES and SIMS requiresmore attention because of potential problems with electron orion beam damage or charging, or both. This guide will notewhen specimen preparation is significantly different among theth
13、ree techniques.5.2 The degree of cleanliness required by surface sensitiveanalytical techniques is often much greater than for other formsof analysis.1This guide is under the jurisdiction of ASTM Committee E42 on SurfaceAnalysis and is the direct responsibility of Subcommittee E42.03 onAuger Electro
14、nSpectroscopy and X-Ray Photoelectron Spectroscopy.Current edition approved May 1, 2009. Published May 2009. Originallyapproved in 1990. Last previous edition approved in 2002 as E 1078 02.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at servic
15、eastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The boldface numbers in parentheses refer to a list of references at the end ofthis standard.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Consho
16、hocken, PA 19428-2959, United States.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 surface ofinterest. Hand creams, skin oil
17、s, 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, adhesives,contaminants, or other foreign matt
18、er.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, with scratches or a permanent ink marker) s
19、o 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 effects ofsputtering, electron beam expos
20、ure, 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 care if the surfacebecomes less reactive. A
21、lternatively, 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 is desired, a suitable grade solvent sho
22、uld 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 pressurized gas. In some instances, the co
23、ntaminationitself 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 information sought can influ-ence the prep
24、aration 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 analytical chamber. Furthermore, it mayalso be po
25、ssible 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 analyticaltechniques because such specimens may become damag
26、ed 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. Fur-thermore, exposure to an electron beam (for example, in aSEM) ca
27、n 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. Sources of Specimen Contamination7.1 Tools,
28、 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 handle specimens should be made of mate
29、rials 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 to magnetic fields. Tools should never
30、 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, and other materialsthat are often found o
31、n 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 cross-contamination of specimens. Avoid
32、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 attempt to clean a specimen. They, too
33、,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 particle filters can reduce oil andparti
34、cles 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 that were inequilibrium with the ambient
35、 environment prior to insertioninto 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 cause changes insurface chemistry of the specime
36、ns 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 between the surface of a specimenand the residual
37、gases in the analytical chamber. The incidentE1078092flux 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 discussed in Guide E 983.7.4.2 Residual g
38、ases 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 with time are observed, thenthe interpreta
39、tion 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 SIMS, AES, andXPS depth profiles not on
40、ly 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 methods. In somecases, sputtered material m
41、ay 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 otherspecimens in the chamber. High vapo
42、r 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, andother porous materials, greases and oil
43、s, 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 diffusion can be a problem,especially w
44、ith 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 surfaces can be resputtered backonto the surf
45、ace 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 beams can be important,especially when
46、 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 hasnot been contaminated. Even in clean lab
47、oratory 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 by means of particles, liquids,gases, or
48、 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 thant
49、he 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 appro-priate for storing flat specimens (face down toward the bevel sothat only the edges of the sample touch the container).8.1.2.2 Containers such as glove boxes, vacuum chambers,and desiccators may be excellent choices for storage ofspecimens. A vacuum desiccator may be preferable to astandard unit and should be maintained free of grease andm
