1、 Reference number ISO 22048:2004(E) ISO 2004INTERNATIONAL STANDARD ISO 22048 First edition 2004-08-15 Surface chemical analysis Information format for static secondary-ion mass spectrometry Analyse chimique des surfaces Protocole de linformation pour la spectromtrie de masse des ions secondaires (SI
2、MS) en mode statiqueISO 22048:2004(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing t
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5、iat at the address given below. ISO 2004 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the addres
6、s below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2004 All rights reservedISO 22048:2004(E) ISO 2004 All rights reser
7、ved iiiContents Page Foreword iv Introduction v 1 Scope 1 2 Normative references . 1 3 Terms, definitions and conventions . 1 4 Symbols (and abbreviated terms) . 1 5 Description of information format. 2 5.1 General. 2 5.2 Additional rules and definitions 3 5.3 The format 4 5.3.1 Content of the infor
8、mation format. 4 5.3.2 Definition of items in the format 5 Annex A (informative) Examples of formatted data 7 A.1 Example of data acquired using a time-of-flight mass spectrometer . 7 A.2 Example of data acquired using a magnetic sector mass spectrometer 8 A.3 Example of data acquired using a quadru
9、pole mass spectrometer 8 Bibliography . 10 ISO 22048:2004(E) iv ISO 2004 All rights reservedForeword ISO (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
10、out through ISO technical committees. Each member body interested in a subject for which a technical 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
11、collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical 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 Internationa
12、l Standards. Draft International Standards adopted by the technical committees are circulated to the 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 eleme
13、nts of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 22048 was prepared by Technical Committee ISO/TC 201, Surface chemical analysis, Subcommittee SC 3, Data management and treatment. ISO 22048:2004(E) ISO 2004
14、 All rights reserved vIntroduction ISO 14976 provides a digital data transfer format for surface chemical analysis. That format provides basic information about the data acquisition, but data required for calibration does not specifically include certain detailed aspects necessary to interpret stati
15、c secondary-ion mass spectrometry (static SIMS) data. That format also contains the spectral data and information about the abscissa increment and its value in the spectrum. Additional data, such as the mass scale calibration data are assembled into information packages with a defined format to be t
16、ransmitted either within a file conforming to ISO 14976 or separately. In this way, information formats for AES and XPS have been defined in ISO 14975 1 . For static SIMS, it is important to be able to store and transfer the data, as acquired, for instance using the time-of-flight time scale. Each s
17、pectrum then needs associated calibration parameters to convert the time scale to a mass scale, where the mass increment in the spectrum varies with mass. The information format defined here contains these data and can be inserted into the block comment lines of ISO 14976. This format is designed to
18、 work with ISO 14976 in such a way that software designed to read the latter functions correctly with this information package added. This International Standard is therefore supplementary to and compatible with ISO 14976. The format is also compatible with ISO 14975 and follows a similar structure.
19、 INTERNATIONAL STANDARD ISO 22048:2004(E) ISO 2004 All rights reserved 1Surface chemical analysis Information format for static secondary-ion mass spectrometry 1 Scope This International Standard provides a digital format to store, and transfer between computers, in a compact way, important calibrat
20、ion and instrumental-parameter data necessary to make effective use of spectral-data files from static SIMS instruments. This format is designed to supplement the data transfer format specified in ISO 14976. 2 Normative references The following referenced documents are indispensable for the applicat
21、ion of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 14976, Surface chemical analysis Data transfer format 3 Terms, definitions and conventions For the purposes of thi
22、s document, the terms and definitions given in ISO 14976 and the following terms and definitions apply, as well as the convention, stated at the end of this clause, concerning the use of the decimal sign. 3.1 package set of text lines which describes information about spectral data In conformance wi
23、th common usage, the decimal sign is given as a point for all items or examples of verbatim computer entries although, in conformance with the ISO/IEC Directives, Part 2, the decimal sign is given as a comma in the rest of the text. 4 Symbols (and abbreviated terms) A ToF calibration coefficient cal
24、ibration coefficient for the term x 2in Equation (4) B ToF calibration coefficient calibration coefficient for the term x in Equation (4) calibration constant in Equation (4) E ion energy in the flight path of a mass spectrometer, in electron volts ISO 22048:2004(E) 2 ISO 2004 All rights reservedL t
25、otal path length of the spectrometer, in metres u unified atomic mass unit M mass scale in units of u divided by the modulus of the charge number of the ion m mass of ion in units of M t measured arrival time referenced to the beam chopper T flight time of ion, in seconds t flight time offset, in se
26、conds x abcissa increment (e.g. channel number, time or mass) SIMS secondary-ion mass spectrometry ToF time-of-flight 5 Description of information format 5.1 General This information format is designed to be inserted into the comment lines of the block in ISO 14976. Thus, extant software programmes,
27、 developed to read ISO 14976, will continue to work effectively. In the case of static SIMS using time-of-flight mass spectrometers, the abscissa scale would have uniform time increments and the supplementary information will be in a human-readable form in the comment lines. Additionally, software d
28、esigned to interpret the present information format will be able to convert the data to a calibrated mass scale and be able to calculate additional parameters to assist analysts. This could have been done prior to transmission and storage of the data but, in that case, to retain optimum mass resolut
29、ion, the whole spectrum would need to be interpolated to the smallest mass increment. That would lead to very large data files and be unwieldy. In order to define the calibration parameters for the mass scale, a generic quadratic function, which encompasses most types of mass analyser, is used. In a
30、 time-of-flight mass spectrometer with an effective flight path of length L, the mass, m, of an ion with energy, E, along the flight path is simply related to the measured arrival time referenced to the beam chopper, t, by 2 2 2( ) Ett m L = (1) where t is a delay offset to allow for the time taken
31、for the primary ion to travel from the beam chopper to the sample. For a ToF system, two calibration coefficients are now defined, where 2 2E A L = (2) and B t = (3) The mass, m, may now be described by a quadratic equation in terms of the abscissa increment, x, which may represent either time or ch
32、annel number: 2 mxx =+ (4) ISO 22048:2004(E) ISO 2004 All rights reserved 3where = A, = 2AB and = AB 2 . Whilst this equation uses an extra non-independent coefficient, it does give the flexibility to describe the mass scale for most spectrometers. For example, a quadrupole spectrometer with a linea
33、r mass scale will have = 0 whereas a magnetic-sector mass spectrometer may require all three independent coefficients. Thus, a three-term calibration, where one term may be zero, covers a wide range of instruments without the software having to read if/then choices. The mass scale calibration shall
34、be calculated using the correct physical model appropriate to the spectrometer, such as Equation (1) for a ToF spectrometer. In the above, it has been assumed that the ion has unit charge. In practice, this is generally true. However, a few ions are multiply charged. This increases E by the multipli
35、cative factor so that the ion mass appears reduced by that factor. In using Equation (4), therefore, m represents the mass divided by the number of electrons representing the charge imbalance of the ion. We will denote this scale by units of “M”. Three archetypal examples of this format are given in
36、 Annex A. The first example is for a ToF SIMS instrument where the mass scale is non-linear in time and the abscissa is recorded in channel numbers in the ISO 14976 file. The spectrometer mass calibration gives A = 3.683406219931798 10 9and B = 3.674421716518492 10 3which were used to calculate the
37、calibration coefficients , and . The second example is for a magnetic-sector instrument with a non-linear mass scale which requires all three independent calibration coefficients. The third example is for a quadrupole instrument with an incorrect linear mass scale recorded in the ISO 14976 file due
38、to instrument drift. Two calibration coefficients, and , are used to correct the mass scale. 5.2 Additional rules and definitions carriage return: 7-bit ASCII character CARRIAGE RETURN followed by 7-bit ASCII character LINE FEED character: the character SPACE or any of the 94 graphic characters spec
39、ified in the 7-bit ASCII character set The 94 graphic characters are: | | ! | “ | # | $ | % | | | ? | | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | | | | | _ | | a | b | c | d | e | f | g | h | i | j | k | l | m | n | o | p | q | r | s | t
40、| u | v | w | x | y | z | | | | | where the vertical bar separates alternatives, given between quotation marks and or “and”. integer: integer number followed by carriage return real number: decimal number or decimal number in exponential notation followed by carriage return text line: line of up to
41、80 characters If the value of any real number or integer in the format is not known, then 1E37 shall be entered. ISO 22048:2004(E) 4 ISO 2004 All rights reserved5.3 The format 5.3.1 Content of the information format The static SIMS information format consists of the following items shown in bold, on
42、 contiguous lines of the text file. All items shall be present and in the order given. static SIMS instrumental-parameter information format identifier primary-ion mass primary-ion pulsed current primary-ion direct current primary-ion pulse width primary-ion bunched-pulse width number of ions per pu
43、lse primary-ion dose primary-ion cycle time number of ion pulses extraction voltage sample holder voltage post-acceleration voltage calibration coefficient alpha calibration coefficient beta calibration coefficient gamma flood gun energy flood gun cycle time flood gun pulsed current end of static SI
44、MS instrumental-parameter information format identifier The analysis source label of ISO 14976 shall be used to identify the primary particle species. Extensible markup language, XML 2 , is the recommended format. For example, SF 5 , is written as SF5. ISO 22048:2004(E) ISO 2004 All rights reserved
45、55.3.2 Definition of items in the format The items below are in the order given in 5.3.1. All texts enclosed by quotation marks define items of the format and are shown in italics here for clarity but are not actually coded in the data files in italics. static SIMS instrumental parameter information
46、 format identifier is the text line “ISO_Static_SIMS_Instrumental_Parameter_Information_Format_1999_September_1”, followed by carriage return. primary-ion mass is a text line. This text line starts with “primary_ion_mass=”, followed by a real number giving the value of the mass of the primary ion in
47、 unified atomic mass units. primary-ion pulsed current is a text line. This text line starts with “primary_ion_pulsed_current=”, followed by a real number giving the value of the pulsed primary-ion current, in pA. primary-ion direct current is a text line. This text line starts with “primary_ion_dir
48、ect_current=”, followed by a real number giving the value of the primary-ion direct current, in nA. primary-ion pulse width is a text line. This text line starts with “primary_ion_pulse_width=”, followed by a real number giving the value of the primary-ion pulse width, in ns, before any bunching. primary-ion bunched pulse width is a text line. This text line starts with “primary_ion_bunched_pulse_width=”, followed by a real number giving the value of the primary-ion pulse width, in ns, af
