1、Designation: E 1016 07Standard Guide forLiterature Describing Properties of Electrostatic ElectronSpectrometers1This standard is issued under the fixed designation E 1016; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、 last revision. A 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 The purpose of this guide is to familiarize the analystwith some of the relevant literature describing the physicalp
3、roperties of modern electrostatic electron spectrometers.1.2 This guide is intended to apply to electron spectrometersgenerally used in Auger electron spectroscopy (AES) andX-ray photoelectron spectroscopy (XPS).1.3 This standard does not purport to address all of thesafety concerns, if any, associa
4、ted 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 Documents2.1 ASTM Standards:2E 673 Terminology Relating to Surface AnalysisE 902 Practice
5、 for Checking the Operating Characteristicsof X-Ray Photoelectron SpectrometersE 1217 Practice for Determination of the Specimen AreaContributing to the Detected Signal in Auger ElectronSpectrometers and Some X-Ray Photoelectron Spectrom-etersE 2108 Practice for Calibration of the Electron Binding-E
6、nergy Scale of an X-Ray Photoelectron Spectrometer2.2 ISO Standards:3ISO 18516 Surface Chemical AnalysisAuger ElectronSpectroscopy and X-Ray Photoelectron SpectrsocopyDetermination of Lateral ResolutionISO 21270 Surface Chemical AnalysisX-Ray Photoelec-tron and Auger Electron SpectrometersLinearity
7、ofIntensity ScaleISO 24236 Surface Chemical AnalysisAuger ElectronSpectroscopyRepeatability and Constancy of IntensityScaleISO 24237 Surface Chemical AnalysisX-Ray Photoelec-tron SpectroscopyRepeatability and Constancy of In-tensity Scale3. Terminology3.1 For definitions of terms used in this guide,
8、 refer toTerminology E 673.4. Summary of Guide4.1 This guide serves as a resource for relevant literaturewhich describes the properties of electron spectrometers com-monly used in surface analysis.5. Significance and Use5.1 The analyst may use this document to obtain informa-tion on the properties o
9、f electron spectrometers and instrumen-tal aspects associated with quantitative surface analysis.6. General Description of Electron Spectrometers6.1 An electron spectrometer is typically used to measurethe energy and angular distributions of electrons emitted froma specimen, typically for energies i
10、n the range 0 to 2500 eV. Insurface analysis applications, the analyzed electrons are pro-duced from the bombardment of a sample surface withelectrons, photons or ions. The entire spectrometer instrumentmay include one or more of the following: (1) apertures todefine the specimen area and emission s
11、olid angle for theelectrons accepted for analysis; (2) an electrostatic and/ormagnetic lens system; (3) an electrostatic (dispersing) ana-lyzer; and (4) a detector. Methods to check the operatingcharacteristics of X-ray photoelectron spectrometers are re-ported in Practice E 902.6.2 Intensity Scale
12、Calibration and Spectrometer Transmis-sion FunctionQuantitative analysis requires the determina-tion of the ability of the spectrometer to transmit electrons, and1This guide is under the jurisdiction of ASTM Committee E42 on SurfaceAnalysis and is the direct responsibility of Subcommittee E42.03 on
13、Auger ElectronSpectroscopy and X-Ray Photoelectron Spectroscopy.Current edition approved June 1, 2007. Published June 20007. Originallyapproved in 1984. Last previous edition approved in 2002 as E 1016 96 (2002).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Cus
14、tomer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from International Organization for Standardization (ISO), 1 rue deVaremb, Case postale 56, CH-1211, Geneva 20, Switzerland, http:/www.iso
15、.ch.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.the resultant detector signal, throughout the spectrometerinstrument. This can be described by an overall electronenergy-dependent transmission function Q (E) and is given bythe pro
16、duct (1,2),4as follows:QE! 5 HE!TE!DE!FE!, (1)where:H(E) = the effect of mechanical imperfections (such asaberrations, fringing fields, etc.),T(E) = electron-optical transmission function,D(E) = detector efficiency, andF(E) = efficiency of the counting systems.Knowledge of this transmission function
17、 permits the cali-bration of the spectra intensity axis (3).Adetailed review of theexperimental determination of the transmission function forXPS (4) and AES (5) measurements has been published.6.3 Energy Scale CalibrationCalibration of the energyscales of AES and XPS instruments is required for (1)
18、meaningful comparison of building-energy or kinetic-energymeasurements from two or more instruments; (2) valid identi-fication of chemical state from such comparisons; (3) effectiveuse of databases containing reported energy values; and (4)asa component of a laboratory quality system. Suitable photo
19、nenergy values forAl and Mg anode X-ray sources often used inXPS measurements are available (6) and reference bindingenergy values for Cu, Au, and Ag have been published (7).Reference kinetic-energy values for Cu, Al, and Au are alsoavailable (8, 9). Binding energy scale calibration procedureshave b
20、een described in the literature for XPS (10,11) andkinetic energy scale calibrations for AES (8, 12-14) measure-ments.6.4 Linearity of Intensity ScaleSee ISO 21270 for meth-ods to evaluate linearity of the intensity scale of AES and XPSspectrometers.6.5 Repeatability and Constancy of Intensity Scale
21、SeeISO 24236 and ISO 24237 for methods to evaluate the repeat-ability and constancy of intensity scales of AES and XPsspectrometers, respectively.6.6 Lateral ResolutionSee ISO 18516 for methods todetermine the lateral resolution of AES and XPS spectrom-eters.6.7 Specimen Area Contributing to the Det
22、ect SignalSeePractice E 2127 for methods to determine the specimen areacontributing to the detected signal in Auger electron spectrom-eters and some X-Ray photoelectron spectrometers.6.8 Calibration ProtocolRecommendations have beenpublished describing spectrometer calibration requirementsand the fr
23、equency with which AES and XPS spectrometersshould be calibrated. (15)7. Literature7.1 Electrostatic AnalyzersSpectrometers commonly usedon modern AES and XPS spectrometer instruments generallyemploy electrostatic deflection analyzers. Auger electron spec-trometers often use cylindrical mirror analy
24、zer (CMA) designs,although concentric hemispherical analyzers (CHA) (alsoknown as spherical deflection (or sector) analyzers) are alsoused. The CHA design is the most common analyzer employedon modern XPS instruments, although double-pass CMAdesigns were also employed on earlier XPS instruments.Reta
25、rding field analyzers (RFA) have historical interest in earlyAES work, but are now commonly used on low energy electrondiffraction apparatus.7.1.1 Electrostatic Deflection Analyzers A review of thegeneral properties of deflection analyzers may be found inreview articles (16,17). More detailed review
26、s are also avail-able where, in addition to the CMA and CHA designs, planemirror, spherical mirror, cylindrical sector, and toroidal deflec-tion analyzers are treated (18-20). As the width of typicalAuger spectral features are several electron volts, the use of aCMA design in conventional AES has su
27、fficed for routineanalysis, particularly for small area analysis where a compro-mise between signal-to-noise and energy resolution is impor-tant. These are commonly used at a resolution defined by thefull-width at half-maximum of the spectrometer energy reso-lution, DE, divided by the electron energ
28、y, E, of 0.25 to 0.6 %.The ability to incorporate an electron source concentric withthe CMA axis has been extensively exploited in scanning-electron microscope instruments to give Auger data as afunction of beam position (that is, images). However, analysisof the Auger spectra from some compounds an
29、d surfacemorphologies may be enhanced by the use of a CHA designwhich can provide better energy resolution (but a lowertransmission) and superior angular resolution. The CHAdesignis most frequently employed on XPS instruments wherespectral features generally have narrow energy widths of 1 eVor less
30、and higher angular resolution is desired for the detectedelectrons than is possible with a CMA. The relationshipbetween the pass energy of various spectrometer designs andthe potential between their electrodes is described in detail(16).7.1.2 Retarding Field AnalyzersThe use of a retardingfield anal
31、yzer (RFA), consisting of concentric, spherical-sectorgrids, is currently used most commonly on electron diffractioninstruments where the angular distribution of the detectedelectrons is examined. See also a brief review of RFA designs(16) and a substantial report on resolution and sensitivity issue
32、s(21).7.2 AperturesThe effects of the spectrometer entrance andexit slits and apertures, their associated fringing fields, as wellas the effect of the divergence of the incident electron trajec-tories on analyzer performance, particularly energy resolution,have also been reviewed (16-20).Adetailed e
33、xamination of theeffects of unwanted internal scattering in CHA and CMAelectron spectrometers has been reported in the literature(22-24).7.3 Lens SystemsInput lens systems are frequently em-ployed in CHA (and cylindrical sector) designs to vary thesurface analysis area (25) and to permit a convenien
34、t locationof the CHA so as to allow access of complementary surfacecharacterization techniques to the sample (26). The electro-static lens design often consists of a coaxial series of electrodesthat define the analysis area on the sample surface and4The boldface numbers in parentheses refer to the l
35、ist of references at the end ofthis guide.E1016072determines the electron trajectories at the input to the analyzer.The lens system also determines the angular resolution andmodifies the transmission characteristics of the spectrometersystem (1). Reviews of electrostatic lens systems incorporatedin
36、surface analysis instruments have been published (16-20,27). Lens systems have also been introduced at the exit ofanalyzers for photoelectron imaging (17,28-30). Methods todetermine the specimen area examined are described in Prac-tice E 1217.7.4 DetectorsDetection of the analyzed electrons is gen-e
37、rally accomplished through the use of an electron multiplier toproduce usable signals. Surface analysis instruments currentlyuse a variety of multipliers, but most are glass upon which aresistive counting is placed. The coating is formulated toprovide a substantial secondary electron yield upon prim
38、aryelectron impact. The multiplier has a potential placed upon it sothat the secondary electrons are accelerated to adjacent coatedsurfaces, thus providing the electron multiplying effect. Mul-tipliers are available in various shapes for both analog andpulse counting amplification modes of operation
39、 (31). Single-channel electron multipliers were common in early instru-ments, but multiple-channel (“multichannel”) electron multi-pliers fabricated into thin plates are now available for use indetectors. See a general review of electron multipliers (32-35).The use of position-sensitive detectors, s
40、uch as resistiveanodes, as well as wedge and strip anodes at the output of suchelectron multipliers, has afforded the ability to also record thespatial (angular) characteristics of the analyzed electrons andhas thus permitted the determination of surface composition asa function of position (“chemic
41、al maps”) in XPS instruments(20,33). A delay-line detector has recently been developed forXPS (34). The detection efficiency of single channel multipli-ers as a function of incident energy, angle of incidence, as wellas count rate have been reported (35). In addition, the influenceof the detector el
42、ectronics and counting systems have also beenexamined (36,37).8. Keywords8.1 electron spectrometersREFERENCES(1) Seah, M. P., and Smith, G. C., “Quantitative AES and XPS: Determi-nation of the Electron Spectrometer Transmission Function andDetector Sensitivity Energy Dependencies for the Production
43、of TrueElectron Emission Spectra in AES and XPS,” Surface and InterfaceAnalysis, Vol 15, 1990, pp. 751766.(2) Smith, G. C., and Seah, M. P., “Standard Reference Spectra for XPSandAES: Their Derivation, Validation and Use,” Surface and InterfaceAnalysis, Vol 16, 1990, pp. 144148.(3) Seah, M. P., “XPS
44、 Reference Procedure for the Accurate IntensityCalibration of Electron SpectrometersResults of a BCR Intercom-parison Co-Sponsored by the VAMAS SCA TWA,” Surface andInterface Analysis, Vol 20, 1993, pp. 243266.(4) Seah, M. P.,“ A System for the Intensity Calibration of ElectronSpectrometers,” Journa
45、l of Electron Spectroscopy and Related Phe-nomenon, Vol 71, 1995, pp. 191204.(5) Seah, M. P., and Smith, G. C., “AES: Accurate Intensity Calibration ofElectron SpectrometersResults of a BCR Intercomparison Co-Sponsored by the VAMAS SCA TWA,” Surface and Interface Analy-sis, Vol 17, 1991, pp. 855874.
46、(6) Schweppe, J., Deslattes, R. D., Mooney, T., and Powell, C. J.,“Accurate Measurement of Mg and Al Ka1,2X-Ray Energy Profiles,”Journal of Electron Spectroscopy and Related Phenomenon, Vol 67,1994, pp. 463478.(7) Seah, M. P., Gilmore, I.S., and Beamson, G., “XPS: Binding EnergyCalibration of Electr
47、on Spectrometers: 5Re-evaluation of the Ref-erence Energies,” Surface Interface aNalysis, Vol 26, 1998, pp.642649.(8) Seah, M. P., Gilmore, I.S., “AES: Energy Calibration of ElectronSpectrometers, III General Calibration Rules.” Journal of ELectronSpectroscopy and Related Phenomena, Vol 83, 1997, pp
48、. 197208.(9) Seah, M.P., “AES: ebergy Calibration of Electron Spectrometers IV: Are-evaluation of the Reference ENergies,: Journal of ELectron Spec-trsocopy anf Related Phenomena, Vol 97, 1998, pp. 235241.(10) Seah, M.P., Gilmore, I.S., Spencer, S.J., “XPSBinding-EnergyCalibration of Electron Spectr
49、ometers4: Assessment of Effects forDifferent X-Ray Sources, Analyser Resolutions, Angles of Emission,and of Overall Uncertainties,” Surface and Interface Analysis, Vol 26,1998, pp. 617641.(11) Powell, C. J., “Energy Calibration of X-ray Photoelectron Spectrom-eters: Results of an Interlaboratory Comparison to Evaluate aProposed Calibration Procedure,” Surface and Interface Analysis,Vol23, 1995, pp. 121132.(12) Seah, M. P., Smith, G. C., and Anthony, M. T., “AES: EnergyCalibration of Spectrometers IAn Absolute, Traceable EnergyCalibration
