US3071707A - Source of beams for producing a high intensity charge carrier beam - Google Patents

Source of beams for producing a high intensity charge carrier beam Download PDF

Info

Publication number
US3071707A
US3071707A US836172A US83617259A US3071707A US 3071707 A US3071707 A US 3071707A US 836172 A US836172 A US 836172A US 83617259 A US83617259 A US 83617259A US 3071707 A US3071707 A US 3071707A
Authority
US
United States
Prior art keywords
source
cathode
lens
anode
cylindrical lens
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
US836172A
Other languages
English (en)
Inventor
Schleich Fritz
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.)
Carl Zeiss AG
Original Assignee
Carl Zeiss AG
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 Carl Zeiss AG filed Critical Carl Zeiss AG
Application granted granted Critical
Publication of US3071707A publication Critical patent/US3071707A/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
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/02—Details
    • H01J37/04—Arrangements of electrodes and associated parts for generating or controlling the discharge, e.g. electron-optical arrangement or ion-optical arrangement
    • H01J37/153—Electron-optical or ion-optical arrangements for the correction of image defects, e.g. stigmators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/02—Details
    • H01J37/04—Arrangements of electrodes and associated parts for generating or controlling the discharge, e.g. electron-optical arrangement or ion-optical arrangement
    • H01J37/06—Electron sources; Electron guns
    • H01J37/065—Construction of guns or parts thereof

Definitions

  • the present invention relates to a source for producing a high intensity beam of charged particles of circular cross section.
  • astigmatic error in beam generation occurs in the emission system components, the cathode, control electrode and anode.
  • the astigmatic error can be attributed to two basic causes.
  • the first cause of the astigmatism is due to the different curvature of the wire cathode in the direction of the wire and in the direction transversely of the wire.
  • the second source of error results from the extension of the emitting surface of the cathode in two directions along the emitting wire.
  • a circular cross section is particularly desirable.
  • the source comprises a wire cathode heated to serve as an emission source for the particles, a control electrode, an anode and a cylindrical magnetic lens adjustable both as to field strength and as to azimuth position of the main axis thereof.
  • the anode and cylindrical lens are combined into a single structural unit. The construction of such a source of a high intensity beam of charged particles is thus simple and economical.
  • the cylindrical lens for correcting the source of astigmatism comprises two permanent magnets radially arranged on a rotatable disc connected to the anode.
  • the magnets are jointly rotatable and reciprocably displaceable in a radial direction to provide means for respectively adjusting the azimuth of the main axis and the field strength of the lens.
  • the cylindrical lens comprises four permanent magnets in the same plane. Two magnets are coupled to a first disc and are arranged radially with separation while the other two magnets are arranged in the same manner on a second disc.
  • the discs are rotatable with respect to each other and jointly with respect to the anode to respectively alter the field strength and azimuthal alignment of the major axis of the lens.
  • the astigmatism can be corrected only with respect to one cause of astigmatic error.
  • the cathode may be fabricated of wire having a semi-circular profile so that an approximately spherical point is formed at the front end of the hairpin-like bent wire cathode.
  • a single cylindrical lens will correct the astigmatism, namely, that part of the astigmatic error caused by extension of the emitting surface along the wire beyond the spherical point.
  • cylindrical lens having multiple electromagnetic poles, such as an eight pole lens, each pole of which is energized by an associated coil.
  • the power supply is developed so that continuous transition of each pole from North to South may be efiected by simple regulating apparatus.
  • a selectable azimuth and variable refractive power of the resulting field may be selected for the application intended. Variations in astigmatic error during operation can be corrected by adjustment of the field from a position outside of the working beam source.
  • FIGURE 1 is a cross section of one embodiment of a beam generating system in accordance with this invention.
  • FIGURE 2 is a section taken along lines IIII of FIGURE 1;
  • FIGURE 3 is a cross-section of another embodiment of this invention.
  • FIGURE 4 is a section taken along lines IV-IV of FIGURE 3;
  • FIGURE 5 is a cross-sectioned view of another embodiment of this invention.
  • FIGURE 6 is a section taken along lines VIVI of FIGURE 5.
  • the source for a beam of charged particles shown in FIGURES 1 and 2 comprise a cathode 1, a control electrode 2 and an anode 3.
  • the cathode is formed of suitable material which may be heated by the passage of current therethrough to effect emission therefrom of charged particles, such as electrons.
  • the control electrode 2 is positioned with respect to the cathode to control the beam generation by the bias thereon.
  • the anode 3 is located with respect to the cathode and the control electrode and is biased to provide a suitable accelerating field for the charged particles.
  • the beam formed thereby passes through an aperture in the anode in a conventional fashion and may be focussed by suitable focussing elements onto a focal plane.
  • a disc 4 is rotatably coupled to the anode by threaded engagement therewith.
  • the disc carries two permanent magnets 5 and 6 positioned on mounting members and 11 respectively which slideably engage radially extending slots in the disc 4.
  • Like pole of the magnets 5 and 6 face each other to generate a magnetic field of the pattern required for a cylindrical lens.
  • the magnets 5 and 6 are biased outwardly by respective springs 7 and 8.
  • An annular ring 9 surrounds the mounting members 10 and 11 in engagement with the outer beveled surfaces thereof in such manner that upward movement of the ring will force the magnets 5 and 6 toward each other.
  • the refractive power of the cylindrical lens formed by the magnetic field of the magnets 5 and 6 may be adjusted by vertical adjustment of the annular ring. Rotation of the disc 4 will rotate the magnets to vary the azimuthal positioning of the cylindrical lens axis.
  • FIGURES 3 and 4 there is shown the cathode 1, control electrode 2, and anode 3 similar to those set forth in connection with FIGURE 1.
  • a disc 12 to the wall of which are affixed permanent magnets 13 and 14 is rotatably coupled to the anode by threaded engagement therewith.
  • FIGURES 5 and 6 may advantageously be employed.
  • FIGURES 5 and 6 there is shown a so-called remote focussing cathode comprising the actual cathode 18,
  • anode 20 is similar to that of FIGURES 1-4.
  • a disc 21 is rotatably coupled to the anode in threaded engagement therewith and carries eight electromagnetic coils 22 to 29, each of which is wound on a suitably shaped pole shoe.
  • the coils and pole shoes of the cylindrical lens shown 5 are potted in a resin 30.
  • the potting seals the coils so that air between the wires of the coils need not be drained out by pumping during evacuation of the system in which the beam generating source is used.
  • the coils are energized from a suitable supply.
  • the polarity of the voltage applied to each coil may be reversed and the amplitude of the current applied thereto regulated.
  • the refractive power of the lens and the azimuthal positioning of the axis of the lens may be selected even during operation of the electron beam source to compensate for changed astigmatic error.
  • FIGURES 1-4 particularly, simple and useful corrective elements for beam generating sources. These embodiments may advantageously be employed for fixed operating conditions as often occur in practice.
  • the embodiment represented in FIGURES 5 and 6 may advantageously be employed where operating conditions vary and the correction for astigmatism error must be variable.
  • the beam generating sources in which the astigmatic error has been compensated in accordance with this invention is particularly applicable to applications in which beams of high intensity are required, such as in the different ways of working material, for example, drilling, milling or welding. In many of such applications, it is, of course, advantageous to control the beam by suitable pulse modulation of the bias of the control electrode to generate a pulsed beam.
  • a generating source for generating a high intensity beam of charged particles of circular cross-section comprising a wire cathode, said cathode being formed in hairpin-like shape, a control electrode, an anode, said control electrode being interposed between said anode and said cathode, and a magnetic field cylindrical lens mounted on said anode to correct the astigmatism of said source, said lens being adjustable both with respect to refractive power and with respect to azimuthal positioning of the major axis of said lens.
  • a source in accordance with claim 1 which includes means for locating the azimuth position of said cathode.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Electron Beam Exposure (AREA)
  • Particle Accelerators (AREA)
US836172A 1958-09-06 1959-08-26 Source of beams for producing a high intensity charge carrier beam Expired - Lifetime US3071707A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEZ6840A DE1133838B (de) 1958-09-06 1958-09-06 Strahlquelle zur Erzeugung eines intensitaetsreichen Elektronenstrahles

Publications (1)

Publication Number Publication Date
US3071707A true US3071707A (en) 1963-01-01

Family

ID=7619912

Family Applications (1)

Application Number Title Priority Date Filing Date
US836172A Expired - Lifetime US3071707A (en) 1958-09-06 1959-08-26 Source of beams for producing a high intensity charge carrier beam

Country Status (6)

Country Link
US (1) US3071707A (xx)
CH (1) CH373488A (xx)
DE (1) DE1133838B (xx)
FR (1) FR1233328A (xx)
GB (1) GB854277A (xx)
NL (1) NL242894A (xx)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3444427A (en) * 1964-03-25 1969-05-13 Siemens Ag Method and device for aligning the field axis of a stigmator in an electron-optical lens system
US3504211A (en) * 1965-05-12 1970-03-31 Hitachi Ltd Electron beam control device for use with a cathode ray tube for dynamic correction of electron beam astigmatism and defocusing
US11483919B2 (en) * 2019-03-27 2022-10-25 Huazhong University Of Science And Technology System of electron irradiation

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1215820B (de) * 1962-08-31 1966-05-05 Telefunken Patent Kathodenstrahlroehre mit einem aus mehreren Elektroden bestehenden Strahlerzeugungssystem
DE3123301C2 (de) * 1981-06-12 1985-08-08 Standard Elektrik Lorenz Ag, 7000 Stuttgart Vorrichtung zum Einstellen von Elektronenstrahlen einer Kathodenstrahlröhre

Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1981245A (en) * 1924-02-20 1934-11-20 Westinghouse Electric & Mfg Co Space-current device
US2157182A (en) * 1935-12-31 1939-05-09 Rca Corp Cathode ray deflecting device
US2165803A (en) * 1936-04-25 1939-07-11 Rca Corp Cathode ray deflecting device
US2362908A (en) * 1942-11-02 1944-11-14 Cathodeon Ltd Cathode ray tube
US2369782A (en) * 1943-04-01 1945-02-20 Rca Corp Electron lens system
US2498354A (en) * 1946-12-03 1950-02-21 Philco Corp Magnetic lens system
US2591159A (en) * 1950-05-29 1952-04-01 Gilfillan Bros Inc Magnetic means for producing compensations and other effects in a cathode-ray tube
US2634381A (en) * 1951-03-26 1953-04-07 Zenith Radio Corp Cathode-ray tube beam-positioning device
DE891119C (de) * 1940-07-09 1953-09-24 Telefunken Gmbh Magnetische Elektronenlinse
US2714678A (en) * 1950-09-03 1955-08-02 Siemens Ag Electron microscopes
US2754443A (en) * 1954-01-22 1956-07-10 Siemens Ag Astigmatically corrected electronic lenses
US2883569A (en) * 1956-01-24 1959-04-21 Herman F Kaiser Magnetic quadrupole focusing system
US2910603A (en) * 1955-10-04 1959-10-27 Philips Corp Device for compensating astigmatism in a magnetic electron lens

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2111231A (en) * 1934-06-27 1938-03-15 Radio Patents Corp Recording device
DE895481C (de) * 1941-08-20 1953-11-02 Siemens Reiniger Werke Ag Elektromagnetische Zylinderlinse
DE857245C (de) * 1948-10-01 1952-11-27 Sueddeutsche Lab G M B H Strahlerzeugungssystem fuer Elektronenstrahlgeraete
DE942518C (de) * 1948-10-02 1956-05-03 Zeiss Carl Fa Einrichtung zur Kompensation der Symmetriefehler von Elektronenlinsen
DE855287C (de) * 1948-10-02 1952-11-10 Sueddeutsche Lab G M B H Linsen und Linsensysteme fuer elektronenoptische Abbildung

Patent Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1981245A (en) * 1924-02-20 1934-11-20 Westinghouse Electric & Mfg Co Space-current device
US2157182A (en) * 1935-12-31 1939-05-09 Rca Corp Cathode ray deflecting device
US2165803A (en) * 1936-04-25 1939-07-11 Rca Corp Cathode ray deflecting device
DE891119C (de) * 1940-07-09 1953-09-24 Telefunken Gmbh Magnetische Elektronenlinse
US2362908A (en) * 1942-11-02 1944-11-14 Cathodeon Ltd Cathode ray tube
US2369782A (en) * 1943-04-01 1945-02-20 Rca Corp Electron lens system
US2498354A (en) * 1946-12-03 1950-02-21 Philco Corp Magnetic lens system
US2591159A (en) * 1950-05-29 1952-04-01 Gilfillan Bros Inc Magnetic means for producing compensations and other effects in a cathode-ray tube
US2714678A (en) * 1950-09-03 1955-08-02 Siemens Ag Electron microscopes
US2634381A (en) * 1951-03-26 1953-04-07 Zenith Radio Corp Cathode-ray tube beam-positioning device
US2754443A (en) * 1954-01-22 1956-07-10 Siemens Ag Astigmatically corrected electronic lenses
US2910603A (en) * 1955-10-04 1959-10-27 Philips Corp Device for compensating astigmatism in a magnetic electron lens
US2883569A (en) * 1956-01-24 1959-04-21 Herman F Kaiser Magnetic quadrupole focusing system

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3444427A (en) * 1964-03-25 1969-05-13 Siemens Ag Method and device for aligning the field axis of a stigmator in an electron-optical lens system
US3504211A (en) * 1965-05-12 1970-03-31 Hitachi Ltd Electron beam control device for use with a cathode ray tube for dynamic correction of electron beam astigmatism and defocusing
US11483919B2 (en) * 2019-03-27 2022-10-25 Huazhong University Of Science And Technology System of electron irradiation

Also Published As

Publication number Publication date
DE1133838B (de) 1962-07-26
FR1233328A (fr) 1960-10-12
GB854277A (en) 1960-11-16
CH373488A (de) 1963-11-30
NL242894A (xx)

Similar Documents

Publication Publication Date Title
US2431077A (en) Cathode-ray tube with revolving magnets and adjustable sleeve
US2416687A (en) Magnetic focussing device
US2442975A (en) Focusing system
US3371206A (en) Electron beam apparatus having compensating means for triangular beam distortion
US2455676A (en) Electron lens correction device
US10504694B2 (en) Scanning electron microscope and method of use thereof
JP2009164054A (ja) 荷電粒子ビーム軌道補正器及び荷電粒子ビーム装置
US3430169A (en) Deflection yoke
US2547994A (en) Electronic microscope
EP0133016A2 (en) Multi-gap magnetic image lens for charged particle beams
US3071707A (en) Source of beams for producing a high intensity charge carrier beam
US3351731A (en) Method and apparatus for treating material with a charged beam
US3028491A (en) Apparatus for producing and shaping a beam of charged particles
US3952198A (en) Electron lens
CN110660633B (zh) 维恩过滤器和带电粒子束成像设备
US2814729A (en) X-ray microscope
US3201631A (en) Short focus lens at focal point of long focus lens
ES438667A1 (es) Un sistema para corregir automaticamente la aberracion de unhaz de particulas cargadas a medida que el haz se desplaza del centro de un campo de deflexion.
US2729759A (en) Beam controlling apparatus
US2727182A (en) Image transformer with electronoptical image projection
US2862129A (en) Device for compensating the astigmatism of electron lenses
US2826716A (en) Beam selection system
US2754443A (en) Astigmatically corrected electronic lenses
US2849634A (en) Linear electron accelerators
GB1355252A (en) Electron lenses of the magnetic field type