EP4049299A1 - Electron source based on field emission and production process for same - Google Patents
Electron source based on field emission and production process for sameInfo
- Publication number
- EP4049299A1 EP4049299A1 EP20824299.0A EP20824299A EP4049299A1 EP 4049299 A1 EP4049299 A1 EP 4049299A1 EP 20824299 A EP20824299 A EP 20824299A EP 4049299 A1 EP4049299 A1 EP 4049299A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- substrate
- crystal
- electron source
- conductor
- nanopipette
- 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.)
- Pending
Links
- 238000004519 manufacturing process Methods 0.000 title claims description 6
- 239000013078 crystal Substances 0.000 claims abstract description 78
- 239000000758 substrate Substances 0.000 claims abstract description 69
- 239000004020 conductor Substances 0.000 claims abstract description 18
- 238000010894 electron beam technology Methods 0.000 claims abstract description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 19
- 238000000034 method Methods 0.000 claims description 13
- 239000008367 deionised water Substances 0.000 claims description 10
- 229910021641 deionized water Inorganic materials 0.000 claims description 10
- 238000000151 deposition Methods 0.000 claims description 9
- 238000010438 heat treatment Methods 0.000 claims description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 4
- 229910052799 carbon Inorganic materials 0.000 claims description 4
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims description 4
- 229910052721 tungsten Inorganic materials 0.000 claims description 4
- 239000010937 tungsten Substances 0.000 claims description 4
- 230000008021 deposition Effects 0.000 claims description 3
- 229910003460 diamond Inorganic materials 0.000 claims description 3
- 239000010432 diamond Substances 0.000 claims description 3
- 230000001747 exhibiting effect Effects 0.000 claims description 3
- 229910052623 talc Inorganic materials 0.000 claims description 3
- 239000000454 talc Substances 0.000 claims description 3
- 239000011800 void material Substances 0.000 claims description 3
- 238000003754 machining Methods 0.000 claims description 2
- 239000000463 material Substances 0.000 description 9
- 230000005684 electric field Effects 0.000 description 8
- 239000012212 insulator Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 238000004377 microelectronic Methods 0.000 description 3
- 238000005136 cathodoluminescence Methods 0.000 description 2
- 238000005229 chemical vapour deposition Methods 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 238000005530 etching Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 229910001596 celadonite Inorganic materials 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 229940052961 longrange Drugs 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 238000005036 potential barrier Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 238000004626 scanning electron microscopy Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 238000002604 ultrasonography Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
- H01J9/02—Manufacture of electrodes or electrode systems
- H01J9/022—Manufacture of electrodes or electrode systems of cold cathodes
- H01J9/025—Manufacture of electrodes or electrode systems of cold cathodes of field emission cathodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
- H01J1/02—Main electrodes
- H01J1/30—Cold cathodes, e.g. field-emissive cathode
- H01J1/304—Field-emissive cathodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
- H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
- H01J29/48—Electron guns
- H01J29/481—Electron guns using field-emission, photo-emission, or secondary-emission electron source
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
- H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
- H01J29/48—Electron guns
- H01J29/485—Construction of the gun or of 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
- H01J37/065—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
- H01J37/073—Electron guns using field emission, photo emission, or secondary emission electron sources
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J2209/00—Apparatus and processes for manufacture of discharge tubes
- H01J2209/01—Generalised techniques
- H01J2209/012—Coating
-
- 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
- H01J2237/06—Sources
- H01J2237/063—Electron sources
- H01J2237/06325—Cold-cathode sources
- H01J2237/06341—Field emission
-
- 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
- H01J2237/26—Electron or ion microscopes
- H01J2237/262—Non-scanning techniques
-
- 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
- H01J2237/26—Electron or ion microscopes
- H01J2237/28—Scanning microscopes
-
- 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
- H01J2237/26—Electron or ion microscopes
- H01J2237/28—Scanning microscopes
- H01J2237/2802—Transmission microscopes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J2329/00—Electron emission display panels, e.g. field emission display panels
- H01J2329/02—Electrodes other than control electrodes
- H01J2329/04—Cathode electrodes
- H01J2329/0407—Field emission cathodes
-
- 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
- H01J37/28—Electron or ion microscopes; Electron or ion diffraction tubes with scanning beams
Definitions
- the present invention relates to a field emission electron source. Electron sources are commonly used in scanning electron microscopes, as well as in cold cathode-based flat panel displays and vacuum microelectronics applications.
- the electron sources currently used in electron microscopes or flat panel displays are based on field emission, or thermionic emission.
- a material (usually a metal or a semiconductor) can spontaneously emit electrons only if it receives and absorbs an energy greater than the work of leaving the material.
- Energy can be provided by many means, such as, for example, in the form of heat, by an electric field, or light irradiation.
- thermionic emission the energy is supplied by the incidence of radiation, in particular light or by heating the substrate.
- the thermionic emission produces intense beams in a low vacuum (greater than 10 2 Pa), the equivalent source being of relatively large size (greater than 10 ⁇ m).
- the brightness of such a source is relatively low (10 9 A / m 2 .sr), knowing that it conditions the resolution accessible with this type of source in a microscope.
- field emission In field emission (or cold emission), the material is subjected to an electric field of the order of 1 V / nm. Under the effect of such a field, electrons tunnel through a potential barrier from the Fermi level, at room temperature. In thermionic emission, heating the material makes it possible to lower the Fermi level to the vacuum level, which frees electrons.
- a source based on this principle can reach a size of less than 10 nm. The brilliance of such a source can reach values of the order of 10 13 A / m 2 .sr.
- the field emission requires a high vacuum (less than 10 6 Pa) for a lifetime greater than 1000 hours. At higher pressures, the state of the tip deteriorates rapidly and no longer emits.
- the Schottky emission is based on the field effect and on the thermionic emission, by application of an electric field to a point, combined with the heating of the substrate.
- the Schottky emission makes it possible to produce intense beams in a low vacuum of about 10 4 Pa, the equivalent size of the source being about 15 nm.
- the brightness of such a beam is therefore also relatively low, of the order of 5.10 10 A / m 2 .sr.
- the shape of the field emitting material affects the emission characteristics. This is because the field emission is very easily obtained from very sharp needles or points, the ends of which have been polished to obtain a substantially hemispherical shape, the radius of which may be less than 100 nm. When polarization is applied, the electric field lines diverge radially from the tip and the paths of the emitted electrons initially follow these field lines.
- This electron source requires an electric field of a few V / pm and can work at pressures greater than 1 Pa , the emissive zone being protected by the crystal.However, this source presents significant instabilities and sometimes exhibits several emission points, which makes it difficult to use in conventional scanning electron microscopy.
- an electron source which is sufficiently stable and bright, in particular to be able to offer a large resolution when used in a scanning electron microscope, without requiring a large input of energy. It is also desirable that this source be robust and have a long lifetime, while being able to be used at relatively high pressures, compared to the sources of the prior art which generally require a high vacuum.
- Embodiments relate to a method of manufacturing an electron source, comprising the steps of: forming a conductive substrate, and arranging a conductor facing the substrate.
- the method comprises steps consisting in: placing an electrically insulating crystal on the substrate facing the conductor, the substrate delimiting with the crystal an empty space comprising at least one roughness located at a distance from the crystal, the crystal having , in a plane parallel to the substrate, dimensions less than 100 nm, and in a direction perpendicular to the plane, a thickness less than 50 nm.
- the method comprises a step of depositing the crystal on the substrate, the substrate exhibiting a natural roughness forming the empty space between the substrate and the crystal.
- the deposition of the crystal on the substrate is carried out by depositing on the substrate a drop containing crystals suspended in deionized water, the drop being produced at an outlet orifice at the tapered end of a nanopipette by exerting pressure on an inlet port of the nanopipette.
- the method comprises steps of: partial filling of the nanopipette with deionized water, local heating of the nanopipette to vaporize the water, the water in vapor form being condensed in the vicinity of the end tapering the micropipette, and filling the nanopipette with deionized water containing suspended crystals.
- the method comprises steps of machining the end of a conductive wire to form a point and, at the top of the point, a plate constituting the conductive substrate.
- the extent of the plateau and the inclination of the tip are adjusted according to a desired divergence of an electron beam produced by the electron source.
- the method comprises steps consisting in: forming a nanotip in the substrate, depositing an insulating layer on the substrate, forming a well in the insulating layer to release the nanotip, filling the well with a sacrificial layer, deposit on the insulating layer and the sacrificial layer a monocrystalline layer, etching the monocrystalline layer to form a monocrystalline plate having an edge plumb with a top of the nanotip, and removing the sacrificial layer to form the empty space between the substrate and single crystal plate.
- Embodiments may also relate to an electron source comprising a conductive substrate and a conductor disposed opposite the substrate, the electron source emitting an electron beam when the conductor is positively polarized with respect to the substrate.
- the source of electrons comprises an electrically insulating crystal arranged on the substrate, facing the conductor, the substrate delimiting with the crystal an empty space comprising at least one roughness located at a distance from the crystal, the crystal having, in a plane parallel to the substrate, dimensions less than 100 nm and a thickness less than 50 nm.
- the crystal is placed on the substrate, the substrate exhibiting a natural roughness forming the empty space between the crystal and the substrate, the crystal being supported by asperities on the surface of the substrate.
- the substrate is formed by a plate at the top of a point at one end of a wire.
- the plate has a width of between 5 and 50 ⁇ m.
- the substrate has a nanotip located at a distance from the substrate, in the empty space under the crystal or in the vicinity of an edge of the crystal, the empty space being formed by a well formed around and above of the nanotip in an electrically insulating layer supporting the crystal.
- the substrate is made of tungsten or of carbon, and the crystal is of diamond or talc.
- the crystal has a width of 50 nm and a thickness of 10 nm, these dimensions being defined to within + or - 10%.
- FIG. 1 is a schematic view of an electron source, according to one embodiment
- FIG. 2 is an enlarged schematic view of the electron source
- FIG. 3 diagrammatically represents an electron microscope head integrating the electron source of FIG. 1
- FIG. 4 diagrammatically represents in section a substrate comprising several sources of electrons, according to another embodiment.
- Figures 1 and 2 show an electron source, according to one embodiment.
- This electron source can be used in particular in a scanning microscope.
- the electron source comprises a conductive wire 1, one end of which is cut into a point 10, and the point is machined to form a plate 11.
- a crystal 20 of an insulating material is deposited on the plate 11.
- the conductive wire 1 can have a diameter D of 100 ⁇ m or more and a length of a few mm.
- the plate 11 may have a diameter d of between 5 to 50 ⁇ m, for example of around one hundred ⁇ m.
- the crystal 20 may have a width (or length) L less than 100 nm, preferably between 10 and 100 nm, for example 50 nm (to within + or - 10%), and a thickness E of less than 50 nm, preferably between 1 and 50 nm, for example 10 nm (within + or - 10%).
- the plate 11 has a natural roughness, comparable to the thickness E of the crystal 20, for example equal to the thickness E to within + or - 50%.
- the roughness of the surface of a material corresponds to the maximum height of the hollows and asperities appearing in this surface, defined in absolute value with respect to the average height of this surface, on the scale of the dimensions of the crystal.
- the shape and dimensions of these asperities being random, some of the asperities of the plate 11, in the space delimited between the plate 11 and the crystal 20, are located at a distance less than the thickness of the plate.
- crystal 20 without this distance being zero, the faces of the crystal being substantially plane (the roughness of the crystal may be less than 0.5 nm).
- the simple deposition of the crystal 20 on the plate 11, combined with the roughness of the latter makes it possible to form a conductive / vacuum / insulating assembly, in which the vacuum is formed by the spaces 14 between the asperities of the plate 11 and the crystal 20. Due to the very small dimensions of crystal 20, it is held firmly on plate 11 by the forces of van der Walls.
- the angle ⁇ formed between the direction of the wire and a generator of the conical tip 10 can be adjusted according to the desired divergence of the electron beam generated at the tip 10, knowing that the smaller the angle ⁇ , the smaller the beam. of electrons produced is divergent.
- the diameter d of the plate also has an influence on the divergence of the electron beam produced, knowing that the larger the diameter d of the plate 11, the less the angle a of the conical part influences the divergence of the beam.
- the wire 1 is made of a conductive material such as carbon or tungsten.
- Tungsten has the advantage of being easy to machine.
- Crystal 20 can be diamond or talc.
- the electron source described above has a relatively long lifetime, even when used at relatively high pressures, of the order of 10 4 Pa or higher.
- the tip 10 at the end of the wire can be produced, for example, by electrochemical etching.
- the plate 11 can be produced by erosion.
- the crystal 20 can be deposited on the plate 11 either using a nanomanipulator (for example of the piezoelectric type), or using a micropipette into which deionized water has been introduced into which several crystals. are in suspension.
- the micropipette makes it possible to produce a microdrop of this mixture at the outlet of the micropipette.
- the drop is then captured by capillary action, by simple contact of the drop with the tip 10.
- the drop on the tip 10 dries quickly and deposits the crystal present in the drop. Crystals can be broken down in water using ultrasound.
- the concentration of water in crystals is adjusted so that the number of crystals per drop is close to one, taking into account the volume of a drop.
- the outlet of the micropipette may be less than 10 ⁇ m in diameter to produce drops of substantially this size by applying pressure. less than 10 kPa, for example 1.5 kPa, at the inlet of the micropipette.
- the micropipette can be manufactured conventionally by stretching a capillary tube using a stretching machine such as the P2000 stretching machine sold by the company SUTTER INSTRUMENT®.
- a nanopipette is used, the outlet orifice of which is less than 500 nm, and partially filled with deionized water, for example using the method described in patent application WO 2013/079874 so that the water reaches the tapered part in the vicinity of the exit orifice of the nanopipette.
- the mixture of deionized water and crystals is then introduced through the inlet of the nanopipette, and naturally mixes by diffusion with the water already present in the nanopipette up to the outlet.
- a drop can be deposited on a support using the nanopipette, then captured by capillary action by the tip 10 by bringing it into contact with the drop.
- the dimensions of the drop deposited on the support depend on the speed at which the nanopipette moves along the support during the ejection of the drop and the pressure exerted at the inlet of the nanopipette.
- the water from the drop on tray 11 evaporates very quickly and only a crystal 20 remains.
- FIG. 3 represents an electron microscope head 40, integrating the source of electrons placed opposite a screen, according to one embodiment.
- the electron microscope may for example be of the scanning, projection or transmission type.
- the wire 1 is fixed to a piezoelectric displacer 42, the tip 10 being placed opposite a diaphragm 41.
- the wire 1 and the diaphragm 41 are connected to a voltage source 43, so as to positively bias the diaphragm 41 which serves thus anode or extractor relative to the wire 1 serving as cathode.
- All the elements of the microscope can be placed in a vacuum chamber (not shown) in which the pressure is lowered to a sufficiently low value, for example to a value between 10 3 and 10 5 Pa.
- the actuator 42 is arranged to adjust the distance between crystal 20 and diaphragm 41.
- An ammeter 47 can be placed between diaphragm 41 and ground to detect the presence of electron beam 15 and measure the intensity of the latter.
- the voltage supplied by the voltage source 43 is gradually increased, the appearance of an electron beam is observed, a non-zero current being detected by the ammeter 47, from approximately 400 V, the diaphragm 41 being at a distance of between 0.5 and 1.5 mm from the crystal 20 or the plate 11. If the voltage supplied by the voltage source 43 is gradually lowered, the measured current stabilizes at a few hundred nA.
- the diaphragm 41 has a diameter of 1 mm.
- the conductor / vacuum / insulator structure makes it possible, thanks to an electric field of the order of a few V / pm, to obtain an electron source with an intensity of the order of a hundred nA. It can be observed that this electron source is very stable and follows a Fowler-Nordheim type regime in a current strength band of ten orders of magnitude. It can also be observed a saturation regime reached at about 10 mA for a voltage applied between the source 1 and the gate 41 of 500 V. Knowing that this phenomenon is generally observed with an electric field of the order of V / nm, it can be assumed that there is an enhancement of the electric field in the volume at the interface between the conductive plate 11 and the insulating crystal 20.
- the tip 10 associated with the crystal 20 produces a beam having a low energy dispersion DE of between 0.2 and 0.4 eV, an equivalent source size of between 0 , 5 and 1.5 nm, and high stability.
- the brightness of this source can reach high values of the order of 10 13 to 10 14 A / m2.sr. This source has an acceptable life of greater than 1000 hours even when it is used under a relatively high pressure (less than 10 3 Pa).
- FIG. 4 represents a multilayer structure, according to one embodiment.
- This structure comprises a substrate 50 on which is deposited a conductive layer 51 which has been etched to form nanotips 31 of a few nanometers in height.
- An insulating layer 52 was then deposited on the conductive layer 51.
- the thickness of the conductive layer 51 is slightly greater than the height of the nanotips 31, so that the height between the top 32 of the nanotips 31 and the upper face of the insulating layer 52 is a few nanometers.
- a monocrystalline layer 53 is formed for example by chemical vapor deposition (CVD - “Chemical Vapor Deposition”). ) using a raw gas containing hydrocarbons and hydrogen.
- the thickness of the layer 53 can be between 5 and 50 nm, for example 10 nm.
- Layer 53 is then etched to form a single crystal plate 21 per nanotip 31, the top 32 of each nanotip being under one of the plates 21 or directly above an edge of one of these.
- an electrically insulating layer 54 is deposited on the plates 21 and the sacrificial layer, then etched to form wells substantially in line with the wells around the nanotips 31.
- the wells are filled with the material of the sacrificial layer, and the whole of the insulating layer 54 and of the sacrificial layer is covered with a conductive layer 55 which is then etched to form the anodes 56. All of the sacrificial material is then removed from the wells to release the nanotips, and thus obtain l arrangement shown in Figure 4.
- the nanotips 31 can be arranged in rows and in columns so as to form a matrix of nanotips which can be used to produce a flat screen operating by cathodo-luminescence, to display moving images.
- the nanotips can be connected to one another row by row and controlled by conductive strips forming anodes 56 arranged in columns, in order to be able to excite a single nanotip located on the row and the column subjected to a voltage.
- the present invention is susceptible of various variant embodiments and various applications.
- the invention is not limited to the materials previously described for the conductive material and the insulating crystal, nor to the shape of the substrate formed at the top of a point.
- the surface of the substrate covered by the crystal can be flat, the natural roughness of the substrate being exploited to form the empty space under the crystal.
Landscapes
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Cold Cathode And The Manufacture (AREA)
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR1912909A FR3103311B1 (en) | 2019-11-19 | 2019-11-19 | ELECTRON SOURCE BASED ON FIELD EMISSION AND ITS MANUFACTURING PROCESS |
PCT/FR2020/052087 WO2021099723A1 (en) | 2019-11-19 | 2020-11-16 | Electron source based on field emission and production process for same |
Publications (1)
Publication Number | Publication Date |
---|---|
EP4049299A1 true EP4049299A1 (en) | 2022-08-31 |
Family
ID=70154487
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP20824299.0A Pending EP4049299A1 (en) | 2019-11-19 | 2020-11-16 | Electron source based on field emission and production process for same |
Country Status (4)
Country | Link |
---|---|
US (1) | US20230005695A1 (en) |
EP (1) | EP4049299A1 (en) |
FR (1) | FR3103311B1 (en) |
WO (1) | WO2021099723A1 (en) |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2983092B1 (en) | 2011-11-30 | 2014-05-02 | Centre Nat Rech Scient | METHOD AND DEVICE FOR FILLING NANOPIPETTES BY DYNAMIC MICRODISTILLATION |
JP6459135B2 (en) * | 2015-03-02 | 2019-01-30 | 国立研究開発法人物質・材料研究機構 | Emitter manufacturing method |
-
2019
- 2019-11-19 FR FR1912909A patent/FR3103311B1/en active Active
-
2020
- 2020-11-16 US US17/756,248 patent/US20230005695A1/en not_active Abandoned
- 2020-11-16 WO PCT/FR2020/052087 patent/WO2021099723A1/en unknown
- 2020-11-16 EP EP20824299.0A patent/EP4049299A1/en active Pending
Also Published As
Publication number | Publication date |
---|---|
WO2021099723A1 (en) | 2021-05-27 |
FR3103311B1 (en) | 2021-10-15 |
US20230005695A1 (en) | 2023-01-05 |
FR3103311A1 (en) | 2021-05-21 |
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