US3761707A - Stigmatically imaging double focusing mass spectrometer - Google Patents

Stigmatically imaging double focusing mass spectrometer Download PDF

Info

Publication number
US3761707A
US3761707A US00155061A US3761707DA US3761707A US 3761707 A US3761707 A US 3761707A US 00155061 A US00155061 A US 00155061A US 3761707D A US3761707D A US 3761707DA US 3761707 A US3761707 A US 3761707A
Authority
US
United States
Prior art keywords
energy
analyser
diaphragm
ions
analyzer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00155061A
Other languages
English (en)
Inventor
H Liebl
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Max Planck Gesellschaft zur Foerderung der Wissenschaften eV
Original Assignee
Max Planck Gesellschaft zur Foerderung der Wissenschaften eV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Max Planck Gesellschaft zur Foerderung der Wissenschaften eV filed Critical Max Planck Gesellschaft zur Foerderung der Wissenschaften eV
Application granted granted Critical
Publication of US3761707A publication Critical patent/US3761707A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J49/00—Particle spectrometers or separator tubes
    • H01J49/26—Mass spectrometers or separator tubes
    • H01J49/28—Static spectrometers
    • H01J49/32—Static spectrometers using double focusing

Definitions

  • ABSTRACT To provide for better energy definition in a stigmatically focussing mass spectrometer with directional and energy focussing, the ions to be analysed travel consecutively through an entry diaphragm, a first analyser, a diaphragm to limit the energy range (energy diaphragm), a second analyser, (the energy dispersion factor of which is equal but opposite to that of the first analyser) and an exit diaphragm.
  • One analyser is a momentum analyser operating with a wedge-shaped magnetic field
  • the other analyser is an energy analyser operating with an electric field
  • the momentum analyser comprises a magnet having mutually opposite plane pole-piece surfaces which are mutually inclined and have straight edges which are located at the interval A parallel to the intersection line of the planes containing the pole-piece surfaces.
  • a device is provided for adjusting the magnetic field intensity B at the interval A 2.10A from the intersection line to the value B L35 p/Ae (e charge of the ions; p momentum of the ions to be detected).
  • the diaphragms between which the impulse analyser is placed are arranged on the intersection line with a mutual interval of approximately 1.28 A, and the energy analyser, which forms a stigmatic image of the entry side one of the two diaphragms between which it is arranged upon the exit side one of the two said diaphragms, contains a spherical condenser or a cylindrical condenser through which the ions travel in planes which pass through the cylinder axis.
  • the present invention relates to a stigmatically imaging mass spectrometer with directional and energy focussing, wherein the ions to be analysed travel consecutively through an entry diaphragm, a first analyser, a diaphragm to limit the energy range (energy diaphragm), a second analyser, the energy dispersion factor of which is equal but opposite to that of the first analyser and an exit diaphragm one analyser is a momentum analyser operating with a wedge-shaped magnetic field, and the other analyser is an energy analyser operating with an electric field.
  • the momentum analyser consists of a magnetic lens which deflects the ions entering from an ion source through the entry slit through approximately 90.
  • the ions of equal momentum leave the magnetic lens, acting as momentum analyser, in the form of a parallel beam, and after travelling through the energy diaphragm, by which there momentum range and hence the energy range is limited, enter a 45 spherical condenser which forms a stigmatic image of the ions of equal mass at a point in an image plane.
  • the above described known mass spectrometer has the disadvantage that the energy range (energy window) of the ions to be analysed cannot be adjusted satisfactorily because the ray path is telecentric in the region of the energy diaphragm (i.e., parallel ion beams travel through the energy diaphragm). Therefore any narrowing of the energy diaphragm involves an undesirable reduction in the transmission and hence in the sensitivity of detection of the mass spectrometer.
  • the known spectrograph does not form a stigmatic mage; i.e., it focusses only in one plane and not at right angles thereto, so that the sensitivity here is impaired by the loss of ions which become lost due to the fact that no focussing occurs at right angles to the deflection plane.
  • a stigmatically imaging mass spectrometer has a momentum analyser which contains a magnet with mutually opposite plane pole-piece surfaces which are mutually inclined and have straight edges which lie at the interval A, parallel to the intersection line of the planes containing the pole-piece surfaces, and also a device for adjusting the magnetic field intensity B, at the interval A 2.10A,, from the intersection line to the value B 1.35 p/Ae (e charge of the ions p momentum of the ions to be detected).
  • the diaphragms between which the momentum analyser is placed are arranged on the intersection line with a mutual interval of approximately 1.28A, and the energy analyser, which forms a stigmatic image of the entry-sided one of the two diaphragms between which it is arranged upon the exit-sided one of the two said diaphragms, contains a spherical condenser or a cylindrical condenser through which the ions travel in planes which pass through the cylinder axis.
  • the spherical condenser is preferably combined with a circular electric lens, preferably an Einzel-lens.
  • the energy analyser is preferably arranged between the entry diaphragm and the energy diaphragm, and the momentum analyser is placed between the energy diaphragm and the exit diaphragm.
  • the present stigmatically imaging mass spectrometer is particularly suitable for the analysis of ions with relatively strongly scattered initial energies, such as occur, e.g., when material is sputtered by means of' an ion probe.
  • FIG. 1 shows a schematic plan of a first exemplary embodiment of a mass spectrometer according to the invention
  • FIG. 2 shows a side elevation, partly sectioned, in a plane 22 of FIG. 1;
  • FIG. 3 shows schematic plan of a mass spectrometer according to a second exemplary embodiment of the invention
  • FIG. 4 shows a partly sectioned side elevation along a second 44 in FIG. 3;
  • FIG. 5 shows a schematic plan of a mass spectrometer according to a third exemplary embodiment of the invention.
  • FIG. 6 shows a side elevation in the direction of the arrows 66 in FIG. 5, and
  • FIG. 7 shows a sectional elevation in a plan 77 of F1. 5.
  • FIGS. 1 and 2 contains a momentum analyser which operates with a magnetic field which is generated between two plane mutually inclined pole-piece surfaces which form a wedge shaped magnetic field gap.
  • the field lines are circular arcs, the centres of which lie on the intersection line 10 of the planes containing the two pole-piece surfaces II.
  • the field intensity between the pole-pieces is inversely proportional to the interval from the intersection line 10. In such a field, charged particles describe cycloidal paths.
  • the focussing occurs in second approximation, and the interval of the focussing point from the source point is 1.28 A.
  • a spherical condenser As energy analyser in the exemplary embodiment according to FIG. 1 a spherical condenser is used, which is likewise known in principle (see e.g., German Pat. No. 651,008; Z.Naturf. 12a (1957) 28-33).
  • the energy dispersion y(AU) of a spherical condenser in the Y direction i.e. the interval, calculated along the Y coordinate (see FIG. 1), between the focussing points of ions whose energies differ by AU, is
  • the energy dispersion of the spherical condenser In order to obtain double focussing i.e., both directional and energy focussing the energy dispersion of the spherical condenser must be made equal but opposite to that of the magnetic field.
  • the energy dispersion y,,,(AU) of the magnetic field for a specific mass is equal to half the momentum dispersion, therefore y,,.(AU) 1.03.4 AU/U
  • the condition for double focussing is therefore L sin D/(l-U,,./U,,) 1.03/1
  • the ions to be analysed which may have been generated, e.g., by sputtering by means of an ion probe, enter through an entry diaphragm 24 and then pass through a diaphragm 26 limiting the aperture angle and the electric field of the spherical condenser 15, by which ions of equal energy in the ion beam entering through the entry diaphragm 24 become focussed upon a point (e.g., the point 13) on the intersection line 10.
  • the energy diaphragm 28 is placed in the focussing plane in which the focussing points for the various energies lie.
  • the ions then enter the magnetic field between the pole-piece surfaces 11, and ions whose momentum satisfies the equation (1) become focussed upon a point 12 in the aperture of the exit diaphragm 14.
  • the type of ions to be detected can be selected by adjusting the magnetic field intensity B For a specific field intensity, only such ions can pass through the exit diaphragm 14 at any time as satisfy the condition of equation (I) i.e., ions which exhibit a specific ratio of mass to charge.
  • FIGS. 3 and 4 schematically illustrate an exemplary embodiment in which the energy analyser contains a 45 spherical condenser 15' which is preceded by a circular ion lens 30.
  • the refractive power of this ion lens is adjusted by means of the potential of the centre electrode 32 so that an image of the source point in the entry diaphragm 24 is formed in the plane of the energy diaphragm 28.
  • the construction of this embodiment corresponds to the exemplary embodiment according to FIGS. 1 and 2, and corresponding parts are designated by the same reference numerals.
  • the energy analyser consists of a cylindrical condenser through which the ions travel in planes which pass through the cylindrical axis (cylindrical mirror analyser).
  • Such analysers are known in principle, see., e.g., Z.Phys. 147 (1.957) 228 to 240 and Rev. Sci. Instr. 38 (1967) 1210 to 1216.
  • the energy dispersion AZ of the cylindrical mirror condenser 15" (FIGS. 5 and 6) in the direction of the cylinder axis 34 is AZ a cos 0/sin 0 (2K cos 0 l) AU/U,
  • the energy dispersion in the Y direction (direction at right angles to the axis of the exiting beam) is v(AU) AZ sinO a cos6/sin 9(2K,,cos l) AU/U
  • the condition for double focussing in this case is therefore a cos6/sin 6(2K cos 01) 1.03/1
  • FIG. 5 illustrates a particularly favourable special case.
  • K 1.31 and 0 42.3 For by choosing K 1.31 and 0 42.3", directional focussing occurs in second approximation.
  • the interval Z between the source point 42 in the entry diaphragm 24 and the image point 13 on the intersection line is then 6.120.
  • the condition for double focussing in this case is FIG. 5 therefore represents a mass spectrometer consisting of mechanically simple components which is double focussing in first approximation and forms a stigmatic image in second approximation.
  • this embodiment also corresponds to that according to FIGS. 1 and 2.
  • a second analyzer having an energy dispersion factor which is equal to and opposite to that of the first analyzer; and an exit diaphragm (14); one of the analyzers being a momentum analyzer having a wedge-shaped magnetic field, and the other analyzer being an energy analyzer having an electric field;
  • the momentum analyzer comprising a magnet having mutually opposite plane pole-piece surfaces (11) which are mutually inclined and have straight edges which are parallel and spaced by a distance A, from the intersection line (10) of the planes containing the pole-piece surfaces (11) and parallel to said intersection line, and the magnetic field intensity 8,, at the distance interval being defined y from the intersection line ('10) being adjusted to the value 8,, 1.35p/Ae, wherein e charge of the ions; p momentum of the ions to be detected; the diaphragms (14, 28) between which the momentum analyzer is placed are arranged on the intersection line (10) with a mutual spacing interval of approximately 1.28 A;
  • the energy analyzer which forms a stigmatic image of the diaphragm (24) at the entry side thereof on the diaphragm (28) located at the exit side thereof, including a spherical condenser (l5, 15) or a cylindrical condenser (15"), the ions travelling through the condenser in planes which pass through the cylinder axis (34), ions of equal energy being focussed on the energy diaphragm (28).
  • Mass spectrometer according to claim 1, wherein the spherical condenser (15) is a symmetrically grounded condenser (15) having an entry axis, said entry axis being oriented at the distance L 1.03A to be parallel to the intersection line (10) of the planes passing through the pole-piece surfaces (11).
  • Mass spectrometer according to claim 1 wherein the energy analyzer includes a 45 spherical condenser (15') and a circular ion lens (30) located in advance of said spherical condenser.
  • Mass spectrometer according to claim 1, wherein the energy analyzer includes a cylindrical condenser (15") having an axis, an outer cylinder (40) and an inner cylinder (38), the axis (34) subtending an angle 0 of 42.3 with the axis (36) of the entering ion beam;
  • radius -aof the inner cylinder (38) is equal to 0274A, and wherein the energy of the entering ions and the voltage of the outer cylinder, and its radius have the relationship:

Landscapes

  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Other Investigation Or Analysis Of Materials By Electrical Means (AREA)
  • Electron Tubes For Measurement (AREA)
US00155061A 1970-06-26 1971-06-21 Stigmatically imaging double focusing mass spectrometer Expired - Lifetime US3761707A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2031811A DE2031811B2 (de) 1970-06-26 1970-06-26 Doppelfokussierendes stigmatisch abbildendes Massenspektrometer

Publications (1)

Publication Number Publication Date
US3761707A true US3761707A (en) 1973-09-25

Family

ID=5775115

Family Applications (1)

Application Number Title Priority Date Filing Date
US00155061A Expired - Lifetime US3761707A (en) 1970-06-26 1971-06-21 Stigmatically imaging double focusing mass spectrometer

Country Status (7)

Country Link
US (1) US3761707A (fr)
BE (1) BE769073A (fr)
DE (1) DE2031811B2 (fr)
FR (1) FR2099837A5 (fr)
GB (1) GB1345973A (fr)
LU (1) LU63411A1 (fr)
NL (1) NL7108831A (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3842269A (en) * 1971-10-05 1974-10-15 Max Planck Gesellschaft Mass spectrometer of high detection efficiency
US3922544A (en) * 1972-09-01 1975-11-25 Strahlen Umweltforsch Gmbh Device for separation of sputtered neutrals and high energy ions from sputtered low energy ions
US3949221A (en) * 1973-08-09 1976-04-06 Max-Planck-Gesellschaft Zur Forderung Der Wissenschaften E.V. Double-focussing mass spectrometer
US5128543A (en) * 1989-10-23 1992-07-07 Charles Evans & Associates Particle analyzer apparatus and method
US5723862A (en) * 1996-03-04 1998-03-03 Forman; Leon Mass spectrometer utilizing high energy product density permanent magnets
US6184523B1 (en) 1998-07-14 2001-02-06 Board Of Regents Of The University Of Nebraska High resolution charged particle-energy detecting, multiple sequential stage, compact, small diameter, retractable cylindrical mirror analyzer system, and method of use
EP1657736A1 (fr) * 2004-11-15 2006-05-17 ICT Integrated Circuit Testing Gesellschaft für Halbleiterprüftechnik mbH Dispositif à faisceau d 'électrons de haute densité de courant

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5829577B2 (ja) * 1980-06-13 1983-06-23 日本電子株式会社 二重収束質量分析装置
DE3532698A1 (de) * 1985-09-13 1987-03-26 Zeiss Carl Fa Elektronenenergiefilter vom alpha-typ
DE3532699A1 (de) * 1985-09-13 1987-03-26 Zeiss Carl Fa Elektronenenergiefilter vom omega-typ

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3445650A (en) * 1965-10-11 1969-05-20 Applied Res Lab Double focussing mass spectrometer including a wedge-shaped magnetic sector field

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3445650A (en) * 1965-10-11 1969-05-20 Applied Res Lab Double focussing mass spectrometer including a wedge-shaped magnetic sector field

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Ion Microprobe Mass Analyzer By H. Liebl from the Journal of Applied Physics, Vol. 38, No. 13, Dec., 1967, pages 5277 5283. *
Simple Broad Range Magnetic Spectrometer By J. S. O Connell from The Review of Scientific Instruments, Vol. 32, No. 12, Dec.. 1961, pages 1314 1316. *

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3842269A (en) * 1971-10-05 1974-10-15 Max Planck Gesellschaft Mass spectrometer of high detection efficiency
US3922544A (en) * 1972-09-01 1975-11-25 Strahlen Umweltforsch Gmbh Device for separation of sputtered neutrals and high energy ions from sputtered low energy ions
US3949221A (en) * 1973-08-09 1976-04-06 Max-Planck-Gesellschaft Zur Forderung Der Wissenschaften E.V. Double-focussing mass spectrometer
US5128543A (en) * 1989-10-23 1992-07-07 Charles Evans & Associates Particle analyzer apparatus and method
US5723862A (en) * 1996-03-04 1998-03-03 Forman; Leon Mass spectrometer utilizing high energy product density permanent magnets
US6184523B1 (en) 1998-07-14 2001-02-06 Board Of Regents Of The University Of Nebraska High resolution charged particle-energy detecting, multiple sequential stage, compact, small diameter, retractable cylindrical mirror analyzer system, and method of use
EP1657736A1 (fr) * 2004-11-15 2006-05-17 ICT Integrated Circuit Testing Gesellschaft für Halbleiterprüftechnik mbH Dispositif à faisceau d 'électrons de haute densité de courant
US20060151711A1 (en) * 2004-11-15 2006-07-13 Juergen Frosien High current density particle beam system
US7335894B2 (en) 2004-11-15 2008-02-26 Ict Integrated Circuit Testing Gesselschaft High current density particle beam system

Also Published As

Publication number Publication date
FR2099837A5 (fr) 1972-03-17
NL7108831A (fr) 1971-12-28
LU63411A1 (fr) 1971-09-24
GB1345973A (en) 1974-02-06
BE769073A (fr) 1971-11-03
DE2031811B2 (de) 1980-09-25
DE2031811A1 (de) 1971-12-30

Similar Documents

Publication Publication Date Title
US4072862A (en) Time-of-flight mass spectrometer
CA1263766A (fr) Spectrometre a electrons
US3445650A (en) Double focussing mass spectrometer including a wedge-shaped magnetic sector field
US3955084A (en) Electro-optical detector for use in a wide mass range mass spectrometer
US3889115A (en) Ion microanalyzer
US3761707A (en) Stigmatically imaging double focusing mass spectrometer
JPH0736321B2 (ja) 定量的電位測定用スペクトロメ−タ−対物レンズ装置
Liebl Design of a combined ion and electron microprobe apparatus
US3783280A (en) Method and apparatus for charged particle spectroscopy
Giffin et al. An electro—optical detector for focal plane mass spectrometers
CA1190666A (fr) Methode et appareil de spectrometrie de masse a large bande
US3622781A (en) Mass spectrograph with double focusing
GB1304344A (fr)
GB1533526A (en) Electro-static charged particle analyzers
AU2017220662A1 (en) Extraction system for charged secondary particles for use in a mass spectrometer or other charged particle device
US3678267A (en) Ion source comprising a concave-shaped repeller
US4171482A (en) Mass spectrometer for ultra-rapid scanning
US3842269A (en) Mass spectrometer of high detection efficiency
US3217161A (en) Electrode means to electrostatically focus ions separated by a mass spectrometer on a detector
US4727250A (en) Apparatus for measuring the angular distribution of charged particles scattered by a sample surface
US3387131A (en) Dual orbit mass spectrometer for analyzing ions in the mass range of 1 to 100
US4128763A (en) Energy analyzer for charged particles
SU1460747A1 (ru) Способ энерго-масс-спектрометрического анализа вторичных ионов и устройство дл энергомасспектрометрического анализа вторичных ионов
US3783278A (en) Single magnet tandem mass spectrometer
SU1304106A1 (ru) Электронный спектрометр