BS ISO 16129-2012 Surface chemical analysis X-ray photoelectron spectroscopy Procedures for assessing the day-to-day performance of an X-ray photoelectron spectrometer《表面化学分析 X射线光电.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 16129:2012Surface chemical analysis X-ray photoelectron spectroscopy Procedures for assessing the day-to-day performance of an X-ray photoelectron spectrometerBS ISO 16129

2、:2012 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 16129:2012. The UK participation in its preparation was entrusted to T e c h n i c a l Committee CII/60, Surface chemical analysis.A list of organizations represented on this committee can be obtained on req

3、uest to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2012. Published by BSI Standards Limited 2012.ISBN 978 0 580 72060 4 ICS 71.040.40 Compliance with a Bri

4、tish Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 December 2012.Amendments issued since publicationDate T e x t a f f e c t e dBS ISO 16129:2012 ISO 2012Surface chemical analysis X-

5、ray photoelectron spectroscopy Procedures for assessing the day-to-day performance of an X-ray photoelectron spectrometerAnalyse chimique des surfaces Spectroscopie de photolectrons X Modes opratoires dvaluation de la performance au jour le jour dun spectromtre de photolectrons XINTERNATIONAL STANDA

6、RDISO16129First edition2012-04-15Reference numberISO 16129:2012(E)BS ISO 16129:2012ISO 16129:2012(E)ii ISO 2012 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2012All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any mea

7、ns, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrighti

8、so.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 16129:2012ISO 16129:2012(E) ISO 2012 All rights reserved iiiContents PageForeword ivIntroduction v1 Scope 12 Terms and definitions . 13 Initial approach 14 Initial instrument calibration, alignment and assessment . 15 Test specimen selection 25.1 G

9、eneral information 25.2 The conductive specimen . 25.3 The non-conductive specimen 25.4 Specimen for assessing the X-ray source 46 Collection of reference data . 46.1 General information 46.2 Rapid test of the instrument using a conductive specimen 46.3 Rapid test of the instrument using a non-condu

10、ctive specimen . 86.4 Rapid test of the X-ray source using a phosphor specimen . 86.5 Rapid test of the X-ray source using a uniform conductive specimen 87 Collection of subsequent performance data . 98 Analysis of the performance data . 98.1 General information 98.2 Survey spectrum . 98.3 High-reso

11、lution spectrum from the conductive specimen 108.4 High-resolution spectrum from the non-conductive specimen 108.5 Images from the phosphor specimen 108.6 Images from the uniform conductive specimen .108.7 Spectrum ratios .109 Control charts .15Bibliography .18BS ISO 16129:2012ISO 16129:2012(E)Forew

12、ordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technic

13、al committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of el

14、ectrotechnical standardization.International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the

15、 member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for ident

16、ifying any or all such patent rights.ISO 16129 was prepared by Technical Committee ISO/TC 201, Surface chemical analysis, Subcommittee SC 7, Electron spectroscopies.iv ISO 2012 All rights reservedBS ISO 16129:2012ISO 16129:2012(E)IntroductionXPS instruments are complex, and unsatisfactory performanc

17、e is not always obvious to an operator. It is therefore necessary to provide a test for the correct operation of the system that can be performed regularly and frequently without interfering excessively with the normal work of the laboratory.A full diagnostic test can require many hours or even days

18、; such a test can be appropriate only when the instrument is known to have a fault that needs to be remedied or following a major maintenance procedure. Data acquired before a problem is uncovered become suspect if the spectrometer has not been routinely tested, leading to a loss of confidence in th

19、ose data. If a regular check of the instrument is made, changes in performance can be monitored and corrective action taken in good time to ensure that the data supplied are fit-for-purpose. In the event that a serious fault is uncovered, then only the data since the last check can be in doubt and n

20、eed to be repeated.The purpose of this document is to provide a user with a procedure which is not excessively time-consuming so that it is capable of being completed on a regular and frequent basis, daily if required. The user will then gain an awareness of the current characteristics of the instru

21、ment so that a decision can be made as to whether or not a more complete and time-consuming action is required to return the instrument to a satisfactory level of performance.This procedure is intended to be applied to an XPS instrument that has been correctly calibrated and aligned in accordance wi

22、th ISO standards or manufacturers instructions. It is designed to highlight aspects of the instruments characteristics that differ significantly from those that were measured immediately following the calibration procedure. The procedure does not show how the instrument can be returned to its origin

23、al state. Instead, it guides the user to possible areas of concern. The procedure provides data that can be used in control charts, allowing trends to be observed and acted upon before data quality deteriorates to an unacceptable level for the needs of the analyst. ISO 2012 All rights reserved vBS I

24、SO 16129:2012BS ISO 16129:2012Surface chemical analysis X-ray photoelectron spectroscopy Procedures for assessing the day-to-day performance of an X-ray photoelectron spectrometer1 ScopeThis International Standard is designed to allow the user to assess, on a regular basis, several key parameters of

25、 an X-ray photoelectron spectrometer. It is not intended to provide an exhaustive performance check, but instead provides a rapid set of tests that can be conducted frequently. Aspects of instrument behaviour covered by this International Standard include the vacuum, measurements of spectra of condu

26、ctive or non-conductive test specimens and the current state of the X-ray source. Other important aspects of the instrument performance (e.g. lateral resolution) fall outside the scope of this International Standard. The standard is intended for use with commercial X-ray photoelectron spectrometers

27、equipped with a monochromated Al K X-ray source or with an unmonochromated Al or Mg K X-ray source.2 Terms and definitionsFor definitions of the spectroscopy terms used in this International Standard, the reader is referred to ISO 18115-110.The following abbreviations are used:FWHM full width at hal

28、f maximumPET poly(ethylene terephthalate)PTFE polytetrafluoroethyleneXPS X-ray photoelectron spectroscopy3 Initial approachMost instruments are fitted with a vacuum gauge or gauges. These shall be read frequently and the reasons for large variations understood. A large increase in the pressure can b

29、e due to the properties of a test specimen inside the instrument, a fault in the pumping system, an increase in the temperature of the vacuum system or a leak.Similarly, most instruments have status indicators, either for the system as a whole or for sub-systems or modules. Examples of such indicato

30、rs include water flow rate, data system communications status and electrical power. These can be visible as part of the instrument hardware itself or on screen through an instrument control (data acquisition) system. Such indicators again shall be carefully monitored, along with any measured values

31、that are reported.4 Initial instrument calibration, alignment and assessmentBefore undertaking the procedure described in the following clauses, it is essential that the instrument be calibrated and aligned to an optimum performance level. This is achieved by following the relevant International Sta

32、ndards (References 5 to 9) or the manufacturers instructions. Choose the two settings of the instrument operating conditions that are needed to obtain survey spectra and high-resolution spectra. These should be settings that you regularly use and will be described in Clause 6. Since this is a rapid

33、check, only these two settings are chosen, but these can show faults that are common to all settings. These settings shall always be used in future checks unless they are later found to be less effective than other settings. If the designated settings are changed, data at both the new and old settin

34、gs shall be recorded at the time of change.INTERNATIONAL STANDARD ISO 16129:2012(E) ISO 2012 All rights reserved 1BS ISO 16129:2012ISO 16129:2012(E)5 Test specimen selection5.1 General informationThree types of test specimen are required for the full procedure described in this International Standar

35、d: a conductive specimen, a non-conductive specimen and a specimen suitable for assessing the quality of the X-ray beam (e.g. X-ray spot size, shape and uniformity). The conductive specimen provides information that the basic energy and intensity calibrations of the instrument are consistent from da

36、y to day. When using a non-monochromatic X-ray source having more than one anode material, the survey spectrum shall be examined to check for peaks arising from specimen irradiation from the anode that is not currently being used (this is due to “cross-talk” within the X-ray source). Similarly, when

37、 anode coatings wear, X-rays can be emitted from the substrate material, which is often copper. The survey spectrum shall be examined for peaks arising from X-rays produced from the substrate material. When using a magnesium anode, there can be peaks due to radiation from O K arising from oxidation

38、of the anode coating. These peaks are often called ghost peaks. Table 1 shows the approximate positions of commonly encountered ghost peaks when acquiring an XPS spectrum from silver using Mg K radiation.Table 1 Examples of approximate positions, on the binding-energy scale, of frequently encountere

39、d ghost peaks in a silver spectrum collected using a magnesium anode (The photon energy of Mg K radiation is 1 253,6 eV)Radiation giving rise to ghost peaksPhoton energy eVPossible origin of radiationPeak position on the binding-energy scale eVAl K 1 486,6 From second anode in a twin anode source135

40、O K 524,9 From oxide on the surface of the magnesium anode.1 097Cu L 929,7 From anode substrate 692The non-conductive specimen is required to confirm that the charge compensation system is operating satisfactorily when non-conducting specimens are being analysed. The nature of the specimen that is r

41、equired for assessing the X-ray beam depends upon the type of instrument being used. If the analysis position is visible during the normal operation of the instrument, the quality of the focus and the alignment of the X-ray beam from a monochromated source can be assessed using a phosphor specimen.

42、If the analysis position is not visible in normal operation and the instrument is capable of imaging, a uniform (there should be no features visible in an image of the specimen when the instrument is in its optimum condition), conductive specimen can be used; this can be the conductive specimen ment

43、ioned above. All specimens used shall be large enough to completely fill the defined analysis region of the spectrometer.5.2 The conductive specimenA suitable conductive specimen shall be selected. This should be a material that produces several peaks in the photoelectron spectrum. Preferably, these

44、 peaks should be widely spaced in binding energy. The specimen shall be one whose surface can be cleaned easily by sputtering with noble-gas ions.A pure ( 99,8 %) specimen of silver foil is suitable for this measurement and is recommended. If, however, a different material is commonly analysed in th

45、e users laboratory and conforms to the above criteria, this may be used instead. For convenience, it is assumed here that silver has been selected as the conductive reference material. The same conductive specimen shall be used for all measurements.5.3 The non-conductive specimenNon-conductive speci

46、mens, and conductive specimens with a non-conductive surface layer, charge under the X-ray flux, resulting in shifts in the peak binding energies relative to the uncharged state.2 ISO 2012 All rights reservedBS ISO 16129:2012ISO 16129:2012(E)Select a non-conductive material often studied in your lab

47、oratory, for which you have a good stock and which is capable of being maintained with a surface in a reproducible state. If you are unsure of a material to use, examples that have been found to be useful for tests of instrumental performance are shown in Table 2. Examples are given with different f

48、orms. You might wish to select a specimen with a form similar to that of the specimens most commonly analysed with the instrument. Care shall be taken to select a material which does not exhibit degradation under the X-ray beam during the analysis.Table 2 Examples of non-conductive specimens that ma

49、y be used for this procedureMaterial Form CleaningPET Sheet or fibre Not requiredLaboratory filter paperSheet Not requiredPoly(ethylene terephthalate) (PET) has long been used to evaluate both the energy resolution and the effectiveness of charge control in XPS. It shows a structure of three C 1s peaks together with shake-up intensity. The minimum between the peak at the lowest binding energy and the adjacent peak at a separation of 1,5 eV is highly sensitive to the combination of the instrumental resolution and the un