1、Designation: E 1078 02Standard 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 (e) 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 surfac
3、e 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
4、as ion scattering spectrometry, lowenergy electron diffraction, and electron energy loss spectros-copy, where specimen handling can influence surface sensitivemeasurements.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibilit
5、y 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 Documents2.1 ASTM Standards:E 673 Terminology Relating to Surface Analysis2E 983 Guide for Minimizing Unwanted Electron BeamEffec
6、ts in Auger Electron Spectroscopy2E 1127 Guide for Depth Profiling in Auger Electron Spec-troscopy2E 1829 Guide for Handling Specimens Prior to SurfaceAnalysis23. Terminology3.1 DefinitionsFor definitions of surface analysis termsused in this guide, see Terminology E 673.4. Significance and Use4.1 P
7、roper 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 handled carefully soas to avoid the introduction of spurious contaminants in thepre
8、paration and mounting process. The goal must be topreserve the state of the surface so that the analysis remainsrepresentative of the original.4.2 Auger electron spectroscopy (AES), X-ray photoelec-tron spectroscopy (XPS or ESCA), and secondary ion massspectrometry (SIMS) are sensitive to surface la
9、yers that aretypically a few nanometers (nm) thick. Such thin layers can besubject to severe perturbations caused by specimen handling(1)3or surface treatments that may be necessary prior tointroduction into the analytical chamber. In addition, specimenmounting techniques have the potential to affec
10、t the intendedanalysis.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
11、.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, andSIMS are basically similar, there are some differences. Ingeneral, preparation of specimens for AES and SIMS requir
12、esmore 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 sensitiveanalytical techniques is often much great
13、er 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 surface ofinterest. Hand creams, skin oils
14、and other skin materials are notsuitable for high vacuum.1This guide is under 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 August 10, 2002.
15、 Published August 2003. Originallyapproved in 1990. Last previous edition approved in 1997 as E 1078 97.2Annual Book of ASTM Standards, Vol 03.06.3The boldface numbers in parentheses refer to the list of references at the end ofthis standard.1Copyright ASTM International, 100 Barr Harbor Drive, PO B
16、ox C700, West Conshohocken, PA 19428-2959, United States.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 matter.5
17、.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(e.g., with scratches or a permanent ink marker) so that thea
18、nalysis location can be found once the specimen is inside thevacuum 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 exposure, X-ray
19、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. Alternativel
20、y, 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 should be used
21、that does not affect the specimen material. Note that even highpurity solvents may leave residues on a surface. Cleaning mayalso be accomplished using an appropriately filtered pressur-ized gas. In some instances, the contamination itself may be ofinterest, e.g., where a silicone release agent influ
22、ences adhe-sion. In these cases, no precleaning should 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 preparation of a specimen. If the information soughtcomes from the exterior surface of a
23、 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 possible to expose the layer of interest by in-situfracture, cleaving, or other means.
24、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 damaged ormay be exposed to surface contamination. For example,insulating specimens analy
25、zed by electron microscopy mayhave been coated to reduce charging. This thick coating willrender the specimen unsuitable for subsequent surface analysis.Furthermore, exposure to an electron beam (e.g. in a SEM) caninduce damage or cause the adsorption of surface species fromthe residual vacuum. If i
26、t is not possible to perform the surfaceanalysis first, then the analysis should be done on a different,but nominally identical, specimen or area of the specimen.7. Sources of Specimen Contamination7.1 Tools, Gloves, Etc.:7.1.1 Preparation and mounting of specimens should onlybe done with clean tool
27、s 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 materials that will nottransfer to the specimen or introduce spurious contaminants(for example,
28、Ni tools contaminate Si). Tools should becleaned in high purity solvents and dried prior to use. Non-magnetic tools should be used if the specimen is susceptible tomagnetic fields. Tools should never unnecessarily touch thespecimen surface.7.1.2 Although gloves and wiping materials are sometimesused
29、 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 on gloves. “Powder-free” gloves have notalc and may be better suited. Unnecessary contact with theglov
30、e 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 the useof tapes containing silicones and other mobile species.7.2 Particulate DebrisBlowing ones brea
31、th 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,must be considered a source of possible contamination. Whileparticles are removed from specimens by
32、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 andparticles from these sources. A gas stream can also producestatic charge in many specimens, and this could
33、 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 environment prior to insertioninto the vacuum chamber may desorb surface species, such aswater vapor
34、, 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 specimens of interest.7.4 Effects of the Incident Flux:7.4.1 The incident electron flux in AES, ion flux in
35、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 gases in the analytical chamber. The incidentflux also may locally heat or degrade the specimen, or b
36、oth,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 gases or the incident beam may alter thesurface. One can test for undesirable effects by monitoringsignals fro
37、m the specimen as a function of time, for example bysetting up the system for a sputter depth profile and then notE1078022turning on the ion gun. If changes with time are observed, thenthe interpretation of the results must account for the observa-tion of an altered surface. This method may also may
38、 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 only erode the surface of interest butcan also affect surfaces nearby. This can be caused by poorfo
39、cusing 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 may be deposited onto other speci-mens that may be parked in the analytical chamber.7.5 Analytical
40、 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 vapor pressure elements suchas Hg, Te, Cs, K, Na, As, I, Zn, Se, P, S, etc. should be analyzedwith caution. Many other materials a
41、lso can exhibit high vaporpressures; these include some polymers, foams, and otherporous 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 in
42、serious contamination, as discussed in 7.4.1.7.5.3 Contamination by surface 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,
43、atoms sputtered onto the secondary ionextraction lens or other nearby surfaces 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 cleani
44、ng of the lens can help reduce this effect.7.5.5 The order of use of probing 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 storag
45、e, the morecare must be taken to ensure that the surface to be analyzed hasnot 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 Conta
46、iners suitable for storage should not transfercontaminants to the specimen via particles, liquids, gases, orsurface diffusion. Keep in mind unsuitable containers maycontain volatile species, such as plasticizers, that may beemitted, contaminating the surface. Preferably, the surface tobe analyzed sh
47、ould 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.8.1.2
48、.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 andmechanical pump oil. Cross-contamination between specimensmay also occur if multiple
49、 specimens are stored together.8.1.3 Temperature and HumidityPossible temperature andhumidity effects should be considered when storing or shippingspecimens. Most detrimental effects result from elevated tem-peratures. Additionally, low specimen temperatures and high tomoderate humidity can lead to moisture condensation on thesurface.8.2 Transfer:8.2.1 ChambersChambers that allow transfer of speci-mens from a controlled environment to an analytical chamberhave been reported (4-6). Controlled environments could beother vacuum chambers, glove boxes (dry boxes), glove bags,react
