EP0671755A1 - Elektronen Quelle mit Mikrospitzenemissionskathoden - Google Patents

Elektronen Quelle mit Mikrospitzenemissionskathoden Download PDF

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Publication number
EP0671755A1
EP0671755A1 EP95400494A EP95400494A EP0671755A1 EP 0671755 A1 EP0671755 A1 EP 0671755A1 EP 95400494 A EP95400494 A EP 95400494A EP 95400494 A EP95400494 A EP 95400494A EP 0671755 A1 EP0671755 A1 EP 0671755A1
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EP
European Patent Office
Prior art keywords
electrodes
microtips
electrically conductive
resistive layer
source
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.)
Granted
Application number
EP95400494A
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English (en)
French (fr)
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EP0671755B1 (de
Inventor
Pierre Vaudaine
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.)
Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
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Commissariat a lEnergie Atomique CEA
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Publication of EP0671755A1 publication Critical patent/EP0671755A1/de
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Classifications

    • 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
    • H01J1/3042—Field-emissive cathodes microengineered, e.g. Spindt-type
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J3/00—Details of electron-optical or ion-optical arrangements or of ion traps common to two or more basic types of discharge tubes or lamps
    • H01J3/02—Electron guns
    • H01J3/021—Electron guns using a field emission, photo emission, or secondary emission electron source
    • H01J3/022—Electron guns using a field emission, photo emission, or secondary emission electron source with microengineered cathode, e.g. Spindt-type
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2201/00—Electrodes common to discharge tubes
    • H01J2201/30—Cold cathodes
    • H01J2201/319—Circuit elements associated with the emitters by direct integration

Definitions

  • the present invention relates to an electron source with microtip emissive cathodes ("microtips").
  • Document (1) describes a method for manufacturing a display device by cathodoluminescence excited by field effect emission, the source of microtip electrons being formed on a glass substrate and has a matrix structure.
  • Documents (2), (3) and (4) describe improvements made to this source described in document (1).
  • This improvement is obtained by introducing an electrical resistance mounted in series with the microtips.
  • This electrical resistance is formed from a resistive layer which can be continuous or discontinuous.
  • Figure 1 is a schematic and partial view of a known source of electrons with microtip emissive cathodes, which is described in detail in the document (2) mentioned above.
  • This known source has a matrix structure and comprises a substrate 2, for example made of glass, on which a thin layer of silica 4 is optionally formed.
  • This source also includes, on this layer of silica 4, a plurality of electrodes 5 in the form of parallel conductive strips which act as cathode conductors and constitute the columns of the matrix structure.
  • the cathode conductors are each covered by a resistive layer 7 which can be discontinuous or continuous (except at its ends, to allow the connection of the cathode conductors with polarization means 20).
  • insulating layer 8 Above the insulating layer 8 are formed a plurality of electrodes 10 also in the form of parallel conductive strips.
  • Electrodes 10 are generally perpendicular to the electrodes 5 and play the role of grids which constitute the lines of the matrix structure.
  • a resistive layer can optionally be placed above or below the electrodes 10.
  • At least one of the series of electrodes (cathode conductors or grids) is associated with a resistive layer and each electrode of this series has a lattice structure or mesh structure .
  • the document (3) recommends using cathode conductors in the form of a lattice so that the microtips are arranged in the openings of the lattices of these cathode conductors.
  • the breakdown resistance of a microtip no longer depends, in the first order, on the thickness of the resistive layer but on the distance between this microtip and the corresponding cathode conductor.
  • This further improvement aims to reduce the risk of short circuit between the rows and columns of the source.
  • FIG. 2 is a schematic and partial top view of an electron source described in this document (4) and FIG. 3 is an enlarged view in section along the axis III-III of FIG. 2.
  • This known source with a matrix structure comprises a substrate 1, for example made of glass, and possibly a thin layer 6 of silica on this substrate 1.
  • silica layer 6 On the silica layer 6 is formed a series of parallel electrodes 3, playing the role of cathode conductors, each of these electrodes having a lattice structure.
  • cathode conductors 3 are covered by a resistive layer 9 made of silicon, itself covered by an electrically insulating layer 11 made of silica.
  • this insulating layer 11 is formed another series of parallel electrodes also having a perforated but different structure, this structure being designed to minimize the areas of overlap with the cathode conductors.
  • Electrodes formed above the insulating layer 11 are generally perpendicular to the cathode conductors and constitute the grids 13 of the source.
  • Figures 2 and 3 show a detail of one of the grids of this source known from document (4).
  • This grid bearing the general reference 13, comprises parallel tracks 14 orthogonally cutting other parallel tracks 15.
  • the grid has enlarged zones 17 which here have a square shape.
  • the enlarged zones 17 are located in the center of the meshes of the cathode conductor in the form of a lattice.
  • holes or more exactly micro-holes 18 are preferably formed in the thickness of the enlarged zones of the grid and in the thickness of the insulating layer 11.
  • microtips 19 of the source are arranged in these holes and rest on the resistive layer 9.
  • a set consisting of a microtip and a micro-hole forms a micro-emitter of electrons.
  • the electron microemitters occupy the central regions of the meshes of the mesh of the cathode conductor as well as the enlarged and square zones 17 of the grid.
  • the mesh of the trellis can have different shapes and different dimensions.
  • they can be square and have a side of 25 microns.
  • the number of holes and spikes in each mesh may also vary.
  • microtips are from the cathode conductor, the longer the distance between them, the higher the electrical resistance (due to the resistive layer) through which these microtips are connected to the cathode conductor and therefore the more current electric powering these microtips is weak.
  • the electrical resistance r1 of the microtips situated at the edge of the group of microtips corresponding to a mesh of the cathode conductor has been represented symbolically, and the electrical resistance r2 of the microtips located at the center of this group of microtips, r2 being greater than r1 .
  • the microtips located in the center of the group which are further from the cathode conductor than the microtips located at the edge of this group, emit less electrons than the latter.
  • the object of the present invention is to remedy this drawback.
  • It aims to improve the uniformity of the emission of electrons by the microtips located inside the meshes (or more generally opposite the meshes) of electrodes with lattice structure, in an electron source with emissive cathodes with microtips.
  • each electrically conductive element is located inside the mesh corresponding to this element.
  • each electrically conductive element is equal to the thickness of the electrodes having a lattice structure with which this element is associated.
  • the electrodes which have the trellis structure and which are associated with the electrically conductive elements are the electrodes of the first series of electrodes.
  • each electrically conductive element is inside the mesh corresponding to this element
  • the electrodes having the lattice structure are located under the resistive layer and each electrically conductive element is also under this layer resistive and under the group of microtips corresponding to this element.
  • the electrodes which have the lattice structure and which are associated with the electrically conductive elements are the electrodes of the second series of electrodes.
  • each electrically conductive element is inside the mesh corresponding to this element
  • the electrodes having the lattice structure are on the resistive layer and each electrically conductive element is also on this layer resistive and above the group of microtips corresponding to this element and includes a hole opposite each microtip of this group.
  • microtip source according to the invention which is schematically and partially shown in plan view in FIG. 4 and in enlarged section in FIG. 5 (which is section III-III in FIG. 4) is identical to the source which has been described with reference to Figures 2 and 3 except that it includes in addition to the elements electrically conductive 3a respectively placed inside the meshes of the cathode conductors 3.
  • These electrically conductive elements 3a aim to improve the uniformity of the emission of electrons by standardizing the access resistance to the microtips inside each mesh.
  • each electrically conductive element 3a constitutes an independent plate of electrically conductive material, located in the center of each mesh, under the resistive layer 9, in contact with the silica layer 6 and under the group of microtips 19 corresponding to this mesh.
  • this plate 3a preferably occupies a surface slightly larger than that which is covered by this group of microtips as seen in FIGS. 4 and 5.
  • These plates 3a are advantageously produced during the same photolithography step as that during which the cathode conductors 3 are formed, and from the same photomask and the same metallic layer as those which are used for the manufacture of these cathode conductors (the thickness of the plates 3a thus being equal to the thickness of the cathode conductors).
  • FIG. 5 shows symbolically the electrical resistances r3 connecting each plate 3a to the tracks of the corresponding lattice as well as the resistors r4 between the microtips and these plates 3a respectively.
  • plates 3a makes it possible to obtain the same electrical resistance r3 + r4 under each of the microtips (r3 + r4 representing the access resistance to the microtips), hence a better uniformity of electron emission from these microtips.
  • This electrical resistance of access to the microtips depends, in the first order, on the distance between the conductive plate 3a and the tracks of the corresponding lattice.
  • square conductive plates of 15 ⁇ m side can be used and 0.4 ⁇ m thick (the thickness of the cathode conductors also being 0.40 ⁇ m in this example).
  • the dimensions of the conductive plates are adjusted as a function of the resistivity and of the thickness of the resistive layer 9 and also as a function of the alignment tolerance between the levels of formation of the cathode conductors and of the micro-holes.
  • FIGS. 4 and 5 show a grid with an openwork structure, but of course the invention also applies to a source having respectively full grids.
  • microtip electron source Another example of a microtip electron source is known from document (4) and schematically and partially represented in section in FIG. 6.
  • each cathode conductor 22 is formed on the silica layer 6 and is thus located under the resistive layer 9 and has, in top view, the same forms that the electrode 13 of FIGS. 4 and 5, except that this cathode conductor has no hole at the level of the microtips which are carried by the resistive layer 9.
  • a resistive layer 24 is formed on the insulating layer and provided with holes 26 opposite the microtips, to allow the electrons emitted by them to pass during the excitation of the source.
  • the grid 28 is formed on this resistive layer 24 and has a lattice structure of which we see, in section, tracks 28a in FIG. 6.
  • cathode conductors can be used respectively forming solid strips, parallel to each other.
  • the present invention also applies to the case of FIG. 6 (with perforated or solid cathode conductors) with a view in particular to standardizing the access resistance to each microtip in each mesh of the grids.
  • This variant also has the advantage of standardizing the time of application of the grid-cathode conductor voltage around each microtip.
  • Figure 7 schematically and partially illustrates, in section, a source according to the invention which is identical to the source described with reference to Figure 6 except that it further comprises an electrically conductive element 30 to l inside each mesh of the grids 28, opposite the group of microtips corresponding to this mesh.
  • this electrically conductive element forms an independent plate, of square shape, located inside this mesh, on the resistive layer 24, above the microtip group 19.
  • Each plate 30 comprises holes 32, aligned with the holes 26 and placed respectively opposite the microtips of this group.
  • Each plate 30 is advantageously produced during the same step as that leading to the formation of the grids, from the same conductive layer, the plates 30 thus having the same thickness as the grids 28.
  • the cathode conductors with lattice structures of FIG. 5 could be not under the resistive layer 9 but on the latter (all other things being equal).
  • the grids 28 with a lattice structure of FIG. 7 could not be on the resistive layer 24 but under the latter and in contact with the insulating layer 11.
  • the conductive plates 30 can be either on the resistive layer 24 as seen in FIG. 7, or under this resistive layer 24 and in contact with the insulating layer 11 (these plates 30 then being at the same level as the grids 28, inside the meshes of the latter.

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  • Cold Cathode And The Manufacture (AREA)
  • Cathode-Ray Tubes And Fluorescent Screens For Display (AREA)
EP95400494A 1994-03-09 1995-03-07 Elektronenquelle mit Mikrospitzenemissionskathoden Expired - Lifetime EP0671755B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9402709 1994-03-09
FR9402709A FR2717304B1 (fr) 1994-03-09 1994-03-09 Source d'électrons à cathodes émissives à micropointes.

Publications (2)

Publication Number Publication Date
EP0671755A1 true EP0671755A1 (de) 1995-09-13
EP0671755B1 EP0671755B1 (de) 1997-07-09

Family

ID=9460837

Family Applications (1)

Application Number Title Priority Date Filing Date
EP95400494A Expired - Lifetime EP0671755B1 (de) 1994-03-09 1995-03-07 Elektronenquelle mit Mikrospitzenemissionskathoden

Country Status (5)

Country Link
US (1) US6043592A (de)
EP (1) EP0671755B1 (de)
JP (1) JPH0831347A (de)
DE (1) DE69500403T2 (de)
FR (1) FR2717304B1 (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0713236A1 (de) * 1994-11-18 1996-05-22 Texas Instruments Incorporated Elektron-emittierenden Vorrichtung
FR2739223A1 (fr) * 1995-09-26 1997-03-28 Futaba Denshi Kogyo Kk Dispositif d'affichage a emission de champ
FR2763173A1 (fr) * 1997-05-07 1998-11-13 Futaba Denshi Kogyo Kk Element a emission de champ
FR2764435A1 (fr) * 1997-06-09 1998-12-11 Futaba Denshi Kogyo Kk Element a emission de champ
FR2828956A1 (fr) * 2001-06-11 2003-02-28 Pixtech Sa Protection locale d'une grille d'ecran plat a micropointes

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000215787A (ja) * 1999-01-21 2000-08-04 Nec Corp 電界放出型冷陰極素子、その製造方法及び画像表示装置
US6611093B1 (en) * 2000-09-19 2003-08-26 Display Research Laboratories, Inc. Field emission display with transparent cathode
CA2521304A1 (en) * 2003-04-04 2004-10-21 Lumidigm, Inc. Multispectral biometric sensor
KR100814856B1 (ko) * 2006-10-20 2008-03-20 삼성에스디아이 주식회사 발광 장치 및 표시 장치

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2650119A1 (fr) * 1989-07-21 1991-01-25 Thomson Tubes Electroniques Dispositif de regulation de courant individuel de pointe dans un reseau plan de microcathodes a effet de champ, et procede de realisation
US4990766A (en) * 1989-05-22 1991-02-05 Murasa International Solid state electron amplifier
WO1991012624A1 (en) * 1990-02-09 1991-08-22 Motorola, Inc. Cold cathode field emission device with integral emitter ballasting
EP0461990A1 (de) * 1990-06-13 1991-12-18 Commissariat A L'energie Atomique Elektronenquelle mit Mikropunktkathoden
EP0558393A1 (de) * 1992-02-26 1993-09-01 Commissariat A L'energie Atomique Elektronenquelle mit Mikropunktkathoden und Anzeigevorrichtung mit Kathodolumineszenz erregt durch Feldemission unter Anwendung dieser Quelle
EP0572170A1 (de) * 1992-05-28 1993-12-01 AT&T Corp. Feldemissions-flache Bildwiedergabeanordnung

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2593953B1 (fr) * 1986-01-24 1988-04-29 Commissariat Energie Atomique Procede de fabrication d'un dispositif de visualisation par cathodoluminescence excitee par emission de champ
FR2623013A1 (fr) * 1987-11-06 1989-05-12 Commissariat Energie Atomique Source d'electrons a cathodes emissives a micropointes et dispositif de visualisation par cathodoluminescence excitee par emission de champ,utilisant cette source
US5329207A (en) * 1992-05-13 1994-07-12 Micron Technology, Inc. Field emission structures produced on macro-grain polysilicon substrates
US5541466A (en) * 1994-11-18 1996-07-30 Texas Instruments Incorporated Cluster arrangement of field emission microtips on ballast layer
US5536993A (en) * 1994-11-18 1996-07-16 Texas Instruments Incorporated Clustered field emission microtips adjacent stripe conductors

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4990766A (en) * 1989-05-22 1991-02-05 Murasa International Solid state electron amplifier
FR2650119A1 (fr) * 1989-07-21 1991-01-25 Thomson Tubes Electroniques Dispositif de regulation de courant individuel de pointe dans un reseau plan de microcathodes a effet de champ, et procede de realisation
WO1991012624A1 (en) * 1990-02-09 1991-08-22 Motorola, Inc. Cold cathode field emission device with integral emitter ballasting
EP0461990A1 (de) * 1990-06-13 1991-12-18 Commissariat A L'energie Atomique Elektronenquelle mit Mikropunktkathoden
EP0558393A1 (de) * 1992-02-26 1993-09-01 Commissariat A L'energie Atomique Elektronenquelle mit Mikropunktkathoden und Anzeigevorrichtung mit Kathodolumineszenz erregt durch Feldemission unter Anwendung dieser Quelle
EP0572170A1 (de) * 1992-05-28 1993-12-01 AT&T Corp. Feldemissions-flache Bildwiedergabeanordnung

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0713236A1 (de) * 1994-11-18 1996-05-22 Texas Instruments Incorporated Elektron-emittierenden Vorrichtung
FR2739223A1 (fr) * 1995-09-26 1997-03-28 Futaba Denshi Kogyo Kk Dispositif d'affichage a emission de champ
FR2763173A1 (fr) * 1997-05-07 1998-11-13 Futaba Denshi Kogyo Kk Element a emission de champ
FR2764435A1 (fr) * 1997-06-09 1998-12-11 Futaba Denshi Kogyo Kk Element a emission de champ
FR2828956A1 (fr) * 2001-06-11 2003-02-28 Pixtech Sa Protection locale d'une grille d'ecran plat a micropointes

Also Published As

Publication number Publication date
DE69500403T2 (de) 1998-01-22
FR2717304B1 (fr) 1996-04-05
EP0671755B1 (de) 1997-07-09
FR2717304A1 (fr) 1995-09-15
US6043592A (en) 2000-03-28
DE69500403D1 (de) 1997-08-14
JPH0831347A (ja) 1996-02-02

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