KR101678513B1 - Position adjustable electron gun for electron microscope and electron microscope comprising the same - Google Patents
Position adjustable electron gun for electron microscope and electron microscope comprising the same Download PDFInfo
- Publication number
- KR101678513B1 KR101678513B1 KR1020150145944A KR20150145944A KR101678513B1 KR 101678513 B1 KR101678513 B1 KR 101678513B1 KR 1020150145944 A KR1020150145944 A KR 1020150145944A KR 20150145944 A KR20150145944 A KR 20150145944A KR 101678513 B1 KR101678513 B1 KR 101678513B1
- Authority
- KR
- South Korea
- Prior art keywords
- electron
- tubular side
- electron beam
- electron gun
- vacuum
- Prior art date
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
- H01J37/26—Electron or ion microscopes; Electron or ion diffraction tubes
-
- 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, ion-optical arrangement
- H01J37/06—Electron sources; Electron guns
- H01J37/065—Construction of guns or parts thereof
-
- 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, ion-optical arrangement
- H01J37/06—Electron sources; Electron guns
- H01J37/067—Replacing parts of guns; Mutual adjustment of electrodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J2237/00—Discharge tubes exposing object to beam, e.g. for analysis treatment, etching, imaging
- H01J2237/15—Means for deflecting or directing discharge
- H01J2237/1501—Beam alignment means or procedures
Landscapes
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Electron Sources, Ion Sources (AREA)
Abstract
A filament block or an electronic clerk of an electron gun can be easily provided without a bellows for maintaining a vacuum when the central axis of the filament block or the electronic point source of the electron gun is mechanically offset from the center axis of the anode and the focusing lens. And an electron microscope including the electron gun and the electron gun. The electron gun includes a cathode plate facing the Beneelt cylinder or a field emission electron source and a cathode disposed side by side with the cathode. It is possible to move the upper flat plate on the double o-ring sealing portion or the magnetic fluid sealing portion without providing a bellows for enclosing and sealing the electron beam generating portion in order to align with the secondary anode, thereby facilitating the alignment of the electron beams and simplifying the structure, Easy to use and reusable rubber O-ring. The.
Description
The present invention relates to an electron microscope and an electron gun, and more particularly, to an electron microscope and an electron gun. More particularly, the present invention relates to a metal material for maintaining a vacuum when a central axis of a filament block or an electron point source of the electron gun is mechanically offset from a center axis of the anode and the focusing lens The present invention relates to an electron gun capable of easily adjusting the position of the electron gun and improving the vacuum structure so that the filament block or the electronic point source of the electron gun can be easily moved without assembly of the bellows of the electron gun.
Scanning Electron Microscope (SEM) scans the electron beam two-dimensionally to the sample and detects secondary electrons from the sample and images it. It is composed of a light source, a converging lens, and an objective lens, and is similar to an optical microscope that produces an image using light reflected from a sample surface. An electron gun corresponding to a light source of an optical microscope serves to generate and accelerate electrons and supplies a group of electrons used in the form of electron beams.
Since electrons in an atom have a constant energy in a specific energy orbit due to the action of an electric force with an atomic nucleus, electrons rarely radiate out of the atom unless energy is externally applied. However, the energy barrier (work function) When energy is given, it will pop out. That is, when a metal such as tungsten used as the filament of the electron gun is heated to a high temperature, the electrons bound to the atoms on the surface are released from the bond of the nucleus and released into the vacuum.
The electron gun of the electron microscope can be divided into a thermionic electron gun and a field emission electron gun. Filaments used as cathodes in thermal emission are bent into a V-shaped hairpin with a tungsten line and a diameter of about 100 μm. Tungsten is used as a filament because its work function value is not as large as 4.5 eV and its melting point is very high at 3,650 K. It is heated to about 2,200 K by applying a direct current to the filament. In advanced electron microscopy, LaB 6 (lanthanium hexaboride) is used to increase the electron density generated and heated to 1800 K. Since LaB 6 has a problem that the electron emission is remarkably lowered when the atom is adsorbed on the surface, high vacuum should be maintained.
The electron gun has a filament on the upper part, a Wehnelt cylinder around the filament, and an anode plate on the lower side serving as an accelerating electrode. In the Wehnelt cylinder, a voltage having a negative value is formed by a bias voltage that is more negative than a negative filament, whereby the electrons emitted from the filament are repulsively focused and focused. The electrons emitted from the filament are accelerated by the voltage difference between the cathode filament and the anode plate, and are emitted in a downward direction to form an electron beam.
The field emission electron gun consists of a negative electrode tip, a primary anode and a secondary anode. The point source is tapered to have a radius of curvature of about 600 to 2000 angstroms so that when the strong electric field is applied, the thickness of the potential barrier is reduced so that electrons can easily protrude from the tungsten surface to the tunneling phenomenon . Since the electron beam of uniform energy is obtained from the point source of the field emission type electron gun, a very high electron beam brightness and a small intersection point can be formed and a high resolution can be obtained. The primary anode has a high voltage of several kV to emit electrons from the tip, and the secondary anode accelerates electrons. An acceleration voltage of several tens kV is applied between the secondary anode and the tip. The field emission type can be divided into a heat-free cold cathode field emitter (CFE), a thermally assisted field emitter (TFE), and a schottky field emitter (SE).
The center axis of the electron beam emitted from the electron beam emitting portion including the filament block of the filament block or the field emission electron gun and the primary anode including the filament and the Wehnelt cylinder in the heat radiation type electron gun is the positive electrode plate of the heat- The secondary anode of the electron gun, and the center axis of the focusing lens. When these axes are shifted from each other, not only the electron beam alignment problem but also the number of electrons reaching the sample is reduced, and aberration is generated in the magnetic field lens and the resolution of the sample observation is deteriorated. Also, in the prior art, a vacuum is used to seal a metal gasket, which requires a new metal gasket to be used for disassembling and assembling, which is costly and expensive to manufacture a metal bellows. In order to seal with a metal gasket, a certain force or more must be applied and a large number of assembly screws are required, which is troublesome in disassembling and assembling.
US Patent 4,663,525 discloses a technique for a method for electron gun alignment in an electron microscope. However, the invention disclosed in the above patent has a problem in that when the position is mechanically adjusted, the structure of the filament is complicated, for example, by inserting a bellows in the electron gun to maintain the vacuum of the filament connecting portion.
SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to solve the above problems by providing a vacuum holding and sealing apparatus in which a central axis of an electron beam can be easily aligned with a center axis of a cathode plate or a secondary anode and a center axis of a focusing lens without providing a complex structure such as a bellows, An improved electron gun and an electron microscope including the same.
Means for Solving the Problems In order to solve the above problems, the present inventors have found that, by using a double o-ring or a magnetic fluid seal to airtightly bond the upper surface plate having the electron beam generating portion and the electron beam generating vacuum chamber to move the upper surface plate, And thus the present invention has been completed.
An electron gun for an electron microscope, the electron gun comprising: a tubular side portion having a first vacuum exhaust tube; A flat upper surface portion having an electron beam generating portion at its center facing the upper rim surface of the tubular side portion through an O-ring and facing the inside of the tubular space; An inner flat plate contacting the lower inner surface of the tubular side portion and having an electron beam passing hole at a position opposite to the electron emitting direction of the electron beam generating portion; A tubular side extension having a tubular side portion extending beyond a location in contact with the first bottom portion and having a second vacuum exhaust tube; And an inner flat plate in contact with a lower inner surface of the tubular side surface extending portion and a second lower surface portion having an electron beam passing hole at a position opposite to the electron beam passing hole of the first lower surface portion, Wherein the first bottom surface, the top surface, and the first bottom surface define a first vacuum chamber, wherein the first bottom surface, the tubular side surface extension, and the second bottom surface define a second vacuum chamber, And a plurality of third vacuum exhaust pipes connecting the first O-ring and the second O-ring, the second O-ring contacting the first O-ring and the second O-ring contacting the outside of the edge face, An electron gun for an electron microscope is provided.
The present invention also provides an electron gun for an electron microscope, wherein the electron gun has a first vacuum exhaust pipe and a tubular side portion having a magnetic field generating portion on an upper rim surface; A flat upper surface portion having an electron beam generating portion at its center, which is in contact with an upper rim surface of the tubular side surface via an annular magnetic fluid seal and faces the inside of the tubular space; An inner flat plate contacting the lower inner surface of the tubular side portion and having an electron beam passing hole at a position opposite to the electron emitting direction of the electron beam generating portion; A tubular side extension having a tubular side portion extending beyond a location in contact with the first bottom portion and having a second vacuum exhaust tube; And an inner flat plate in contact with a lower inner surface of the tubular side surface extending portion and a second lower surface portion having an electron beam passing hole at a position opposite to the electron beam passing hole of the first lower surface portion, Wherein the first bottom surface portion and the first bottom surface portion form a first vacuum chamber and the first bottom surface portion, the tubular side surface extension portion, and the second bottom surface portion form a second vacuum chamber, .
The present invention also provides an electron gun for an electron microscope, wherein the plurality of third vacuum exhaust pipes are connected to the second vacuum chamber.
The present invention also provides an electron gun for an electron microscope which is easy to positionally regulate, wherein the circular disk upper surface portion further includes a horizontal moving knob.
The present invention also provides an electron gun for an electron microscope, wherein the electron beam generating unit is easy to control the position of a field emission electron source.
The present invention also provides an electron gun for an electron microscope, wherein the first vacuum chamber and the second vacuum chamber have different degrees of vacuum and are easily adjustable in position.
The present invention also provides an electron gun for an electron microscope, wherein the magnetic field generating portion is a permanent magnet and is easy to adjust the position.
The present invention also provides an electron microscope including the electron gun.
The electron gun of the present invention has a bellows which surrounds the electron beam generating part and seals the electron beam to align the center axis of the electron beam with the anode plate facing the Beneelt cylinder or the field emission electron source and the secondary anode arranged side by side with the primary anode It is possible to move the plate surface of the upper surface of the double o-ring sealing portion or the magnetic fluid sealing portion without installing it, thereby facilitating the alignment of the electron beam and simplifying the structure compared with the use of the bellows and facilitating the assembly and disassembly and reusing the rubber o- to be.
1 is a conceptual view showing an electron gun holding a vacuum with a double O-ring between an upper portion of a tubular side portion and a top surface of a flat plate, according to an embodiment of the present invention.
FIG. 2 is a conceptual view illustrating an electron gun having a structure in which a vacuum is maintained between a top portion of a tubular side surface and a top surface of a flat plate by a double O-ring, and a first space and a second space are connected by a third vacuum tube, according to an embodiment of the present invention.
3 is a conceptual view showing an electron gun holding a vacuum by a magnetic fluid seal between an upper portion of a tubular side portion and a flat plate top portion, according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to the detailed description of the present invention, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms. Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.
1 is a conceptual view showing an electron gun holding a vacuum with a double O-ring between an upper portion of a tubular side portion and a top surface of a flat plate, according to an embodiment of the present invention. The electron gun for an electron microscope according to an embodiment of the present invention includes a
In one embodiment of the present invention, the tubular
In one embodiment of the present invention, the electron source located in the
The electrons emitted from the electron source form an
3 is a conceptual view showing an electron gun holding a vacuum by a magnetic fluid seal between an upper portion of a tubular side portion and a flat plate top portion, according to an embodiment of the present invention. The electron gun for an electron microscope according to another embodiment of the present invention includes a
In one embodiment of the present invention, the tubular
Magnetic fluid is a "magnetically responsive liquid" material developed by NASA's space program as a "plan for transporting spacecraft liquid fuel in space-weightless gravity" in the early 1960s. By adsorbing the surfactant on the surface of the particles with magnetic fine particles (mainly iron oxide) having a particle diameter of about 10 nm, a surfactant adsorbed on the surface of the magnetic fine particles and a dispersion medium (Base liquid), the particles in the dispersion medium are not aggregated And becomes a colloidal state. The dispersion medium of the magnetic fluid may be water, ethers, esters, fluorocarbons or the like depending on the application to be used and the environment to be used.
A magnetic fluid is a simple liquid without magnetic in the absence of a magnetic field, but becomes magnetism when a magnetic field is applied from the outside, and disappears when the magnetic field is removed. That is, the magnetic fluid has no residual magnetism and does not have a hysteresis characteristic, and this property is called super magnetism. The magnetization of the magnetic fluid is proportional to the amount of magnetic particles contained in the magnetic fluid per unit volume and saturates at the saturation magnetization value. A magnetic fluid seal is a component used to prevent the leakage of liquid or gas by using such a magnetic fluid. The strength with which the magnetic fluid is held is determined by the magnetic force, and it is advantageous not only to generate particles due to friction between the two solids sandwiched by the magnetic fluid, but also to use in a very high vacuum region and to have a long life.
The electrons emitted from the electron source form an
In one embodiment of the present invention, the electron gun is employed as an electron gun of an electron microscope, and the electron microscope includes the electron gun, the electron beam control column, and a sample chamber. The electron beam generated from the electron gun passes through the electron
While the present invention has been described in connection with what is presently considered to be the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, .
All technical terms used in the present invention are used in the sense that they are generally understood by those of ordinary skill in the relevant field of the present invention unless otherwise defined. The contents of all publications referred to herein are incorporated herein by reference.
1. Electron beam generator
2. First vacuum chamber
3. Second vacuum chamber
4. Electron Beam Control Column
5. Plate upper surface portion
6. Third vacuum exhaust pipe
7. First vacuum exhaust pipe
8. Second vacuum exhaust pipe
9. The first lower surface portion
10. Tubular side
11. Side extension
19. The second lower surface portion
21. 1st O-ring
22. Second O ring
25. Magnetic fluid seal
26. Magnetic field generator
30. Electron beam
35. Electron beam passing hole
36. Holes for electron beam passing
Claims (8)
The electron gun includes a tubular side portion having a first vacuum exhaust pipe;
A flat top surface portion having an electron beam generating portion in contact with the upper rim surface of the tubular side portion through an O-ring and having an electron beam generating portion facing the inside of the tubular space;
An inner flat plate contacting the lower inner surface of the tubular side portion and having an electron beam passing hole at a position opposite to the electron emitting direction of the electron beam generating portion;
A tubular side extension having a tubular side portion extending beyond a location in contact with the first bottom portion and having a second vacuum exhaust tube;
And an inner flat plate which is in contact with a lower inner surface of the tubular side surface extending portion and has a hole for passing an electron beam at a position facing the hole for electron beam passing of the first lower surface portion,
Said tubular side surface, said flat top surface, and said first bottom surface defining a first vacuum chamber,
Wherein the first bottom surface, the tubular side surface extension, and the second bottom surface define a second vacuum chamber,
Wherein the double O-ring includes a first O-ring in contact with the inside of the rim surface and a second O-ring in contact with the outside of the rim surface, and a plurality of third vacuum exhaust pipes connecting the space between the first O- , ≪ / RTI &
An electron gun for an electron microscope with easy position control.
The electron gun includes a tubular side portion having a first vacuum exhaust pipe and a magnetic field generating portion on an upper rim surface;
A flat plate top portion having an electron beam generating portion at its center, which is in contact with an upper rim surface of the tubular side portion through an annular magnetic fluid seal and faces the inside of the tubular space;
An inner flat plate contacting the lower inner surface of the tubular side portion and having an electron beam passing hole at a position opposite to the electron emitting direction of the electron beam generating portion;
A tubular side extension having a tubular side portion extending beyond a location in contact with the first bottom portion and having a second vacuum exhaust tube;
And an inner flat plate which is in contact with a lower inner surface of the tubular side surface extending portion and has a hole for passing an electron beam at a position facing the hole for electron beam passing of the first lower surface portion,
Said tubular side surface, said flat top surface, and said first bottom surface defining a first vacuum chamber,
Wherein the first bottom surface, the tubular side surface extension, and the second bottom surface define a second vacuum chamber,
An electron gun for an electron microscope with easy position control.
Wherein the plurality of third vacuum exhaust pipes are connected to the second vacuum chamber,
An electron gun for an electron microscope with easy position control.
Wherein the flat upper surface portion further comprises a horizontal moving knob,
An electron gun for an electron microscope with easy position control.
Wherein the electron beam generating portion is a field emission electron emitter,
An electron gun for an electron microscope with easy position control.
Wherein the first vacuum chamber and the second vacuum chamber have different degrees of vacuum,
An electron gun for an electron microscope with easy position control.
Wherein the magnetic field generator is a permanent magnet,
An electron gun for an electron microscope with easy position control.
Electron microscope.
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR1020150145944A KR101678513B1 (en) | 2015-10-20 | 2015-10-20 | Position adjustable electron gun for electron microscope and electron microscope comprising the same |
PCT/KR2016/000076 WO2017069343A1 (en) | 2015-10-20 | 2016-01-06 | Electron microscope electron gun for facilitating position adjustment and electron microscope including same |
US15/576,687 US10128077B2 (en) | 2015-10-20 | 2016-01-06 | Electron microscope electron gun for facilitating position adjustment and electron microscope including same |
CN201680029882.1A CN107636792B (en) | 2015-10-20 | 2016-01-06 | It is easy to the electron microscope electron gun of position adjusting and the electron microscope including it |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR1020150145944A KR101678513B1 (en) | 2015-10-20 | 2015-10-20 | Position adjustable electron gun for electron microscope and electron microscope comprising the same |
Publications (1)
Publication Number | Publication Date |
---|---|
KR101678513B1 true KR101678513B1 (en) | 2016-11-22 |
Family
ID=57540390
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
KR1020150145944A KR101678513B1 (en) | 2015-10-20 | 2015-10-20 | Position adjustable electron gun for electron microscope and electron microscope comprising the same |
Country Status (1)
Country | Link |
---|---|
KR (1) | KR101678513B1 (en) |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5684364A (en) * | 1993-06-03 | 1997-11-04 | Eev Limited | Electron beam tube collector having ceramic shielding means |
JP2000028800A (en) * | 1998-07-08 | 2000-01-28 | Jeol Ltd | Beam irradiator |
KR20090039981A (en) * | 2007-10-19 | 2009-04-23 | 한국과학기술원 | Transmission-type microfocus x-ray tube using carbon nanotube field emitter |
KR101156124B1 (en) * | 2011-04-13 | 2012-07-03 | (주)펨트론 | Electron beam emission apparatus |
-
2015
- 2015-10-20 KR KR1020150145944A patent/KR101678513B1/en active IP Right Grant
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5684364A (en) * | 1993-06-03 | 1997-11-04 | Eev Limited | Electron beam tube collector having ceramic shielding means |
JP2000028800A (en) * | 1998-07-08 | 2000-01-28 | Jeol Ltd | Beam irradiator |
KR20090039981A (en) * | 2007-10-19 | 2009-04-23 | 한국과학기술원 | Transmission-type microfocus x-ray tube using carbon nanotube field emitter |
KR101156124B1 (en) * | 2011-04-13 | 2012-07-03 | (주)펨트론 | Electron beam emission apparatus |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP7182281B2 (en) | Charged particle beam device | |
Egerton | Physical principles of electron microscopy | |
US7218703B2 (en) | X-ray microscopic inspection apparatus | |
US9053899B2 (en) | Method for imaging a sample in a charged particle apparatus | |
US8686380B2 (en) | Charged particle beam apparatus | |
US10903037B2 (en) | Charged particle beam device | |
US20120132802A1 (en) | Gas field ionization ion source apparatus and scanning charged particle microscope equipped with same | |
JP2007522622A (en) | Cathode head with focus control | |
Ul-Hamid et al. | Components of the SEM | |
Egerton et al. | The transmission electron microscope | |
JP2020087930A (en) | Electron guns, electron emission apparatus, and method of manufacturing electron gun | |
JP6095338B2 (en) | Electron gun and charged particle beam device | |
US10128077B2 (en) | Electron microscope electron gun for facilitating position adjustment and electron microscope including same | |
KR101678513B1 (en) | Position adjustable electron gun for electron microscope and electron microscope comprising the same | |
JP4029209B2 (en) | High resolution X-ray microscope | |
US10651005B2 (en) | Innovative source assembly for ion beam production | |
US20190088441A1 (en) | Electron emission tube, electron irradiation device, and method of manufacturing electron emission tube | |
US3728570A (en) | Electron probe forming system | |
Goldstein et al. | Electron optics | |
Williams et al. | Electron sources | |
JP6377920B2 (en) | High intensity electron gun, system using high intensity electron gun, and method of operating high intensity electron gun | |
TWI807604B (en) | Charged particle beam apparatus, scanning electron microscope, and method of operating a charged particle beam apparatus | |
Masood et al. | Emission characteristics of the thermionic electron beam sources developed at EBSDL | |
Zuo et al. | Electron sources |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
E902 | Notification of reason for refusal | ||
E701 | Decision to grant or registration of patent right | ||
GRNT | Written decision to grant | ||
FPAY | Annual fee payment |
Payment date: 20190926 Year of fee payment: 4 |