WO1998032145A2 - Dispositif d'affichage electronique a balayage de surface et procede de fabrication - Google Patents

Dispositif d'affichage electronique a balayage de surface et procede de fabrication Download PDF

Info

Publication number
WO1998032145A2
WO1998032145A2 PCT/US1997/023718 US9723718W WO9832145A2 WO 1998032145 A2 WO1998032145 A2 WO 1998032145A2 US 9723718 W US9723718 W US 9723718W WO 9832145 A2 WO9832145 A2 WO 9832145A2
Authority
WO
WIPO (PCT)
Prior art keywords
emission device
anode
electron
electron field
emitter
Prior art date
Application number
PCT/US1997/023718
Other languages
English (en)
Other versions
WO1998032145A3 (fr
Inventor
Michael D. Potter
Original Assignee
Advanced Vision Technologies, Inc.
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
Priority claimed from US08/964,987 external-priority patent/US6015324A/en
Priority claimed from US08/964,483 external-priority patent/US5872421A/en
Application filed by Advanced Vision Technologies, Inc. filed Critical Advanced Vision Technologies, Inc.
Priority to AU58052/98A priority Critical patent/AU5805298A/en
Priority to JP53437898A priority patent/JP2001525105A/ja
Priority to CA002274664A priority patent/CA2274664A1/fr
Priority to EP97954214A priority patent/EP0948800A2/fr
Publication of WO1998032145A2 publication Critical patent/WO1998032145A2/fr
Publication of WO1998032145A3 publication Critical patent/WO1998032145A3/fr

Links

Classifications

    • 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
    • H01J19/00—Details of vacuum tubes of the types covered by group H01J21/00
    • H01J19/02—Electron-emitting electrodes; Cathodes
    • H01J19/24—Cold cathodes, e.g. field-emissive cathode
    • 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

Definitions

  • This invention relates generally to field-emission devices and fabrication processes therefor, and more particularly to a surface electron display device structure with an anode having an electron sink, fabricated by specially adapted processes.
  • lateral refers generally to a direction parallel to a substrate on which an electronic device is formed.
  • a “lateral field-emission device” refers to a field-emission device formed on a substrate and formed with a structure such that an anode is spaced apart from a field emitter along at least a direction parallel to the substrate.
  • lateral emitter refers to a field emitter made substantially parallel to the substrate of a lateral device, whereby emission of electrons toward the anode occurs generally parallel to the substrate. Examples of such lateral emitters formed of thin films are known in the related art.
  • the term “electron sink” refers to a region on a surface where electrons of a current tend to flow into the surface. Such electron sink regions are described in detail hereinbelow.
  • U.S. Pat. No. 5,543,684 to Kumar et al. describes a field emission cathode which includes a substrate and a conductive layer disposed adjacent the substrate.
  • An electrically resistive pillar is disposed adjacent to the conductive layer, the resistive pillar having a substantially flat surface spaced from and substantially parallel to the substrate.
  • a layer of diamond is disposed adjacent the surface of the resistive pillar.
  • U.S. Pat. No. 5,548,185 to Kumar et al. describes a flat panel display including a plurality of corresponding light-emitting anodes and field-emission cathodes, each of the cathodes including a layer of low work function material having a relatively flat electron emission surface which includes a plurality of electron emission sites and a grid assembly positioned between the anodes and cathodes to control emission to the anodes from the corresponding-cathodes.
  • the grid assembly includes a conductive layer deposited between the plurality of anodes and cathodes and over interstices between the cathodes, the conductive layer having apertures therein, the cathodes being aligned with, and of the same size as, the apertures.
  • Pat. No. 5,659,224 to Kumar et al. describes a cold cathode display device which includes a cathode having a layer of conductive material and a layer of low-effective work function material deposited over the conductive material wherein the low-effective work function material has an emission surface comprising a plurality of distributed localized electron emission sites, which may have electrical properties which are discontinuous from each other.
  • the emission surface may be relatively flat.
  • U.S. Pat. No. 5,558,554 to Finklea, et al. describes a method for fabricating a field- emission device anode having a multiplicity of grooves for use in a field-emission flat panel display.
  • U.S. Pat. No. 5,449,970 to Kumar et al. describes a matrix-addressed diode flat panel display of field-emission type which utilizes a diode (two terminal) pixel structure.
  • the flat panel display includes a cathode assembly having a plurality of cathodes. Each cathode includes a layer of cathode conductive material and a layer of a low effective work-function material deposited over the cathode conductive material.
  • the flat panel display includes an anode assembly having a plurality of anodes, each anode including a layer of anode conductive material and a layer of cathodoluminescent material deposited over the anode conductive material.
  • the anode assembly is located proximate the cathode assembly to receive charged particle emissions from the cathode assembly,and the cathodoluminescent material emits light in response to the charged particle emissions.
  • the flat panel display of U.S. Pat. No. 5,449,970 further includes the capability for selectively varying field emission between the plurality of corresponding light-emitting anodes and field-emission cathodes to effect an addressable grey-scale operation of the flat panel display.
  • the purpose of the invention is a flat panel display having a plurality of display cells, each cell having improved brightness and fill factor.
  • an object of the invention is a display cell useful for such displays, having an anode with non-uniform resistivity.
  • a more specific object is an anode for a field-emission device having at least one region of relatively lower resistivity compared to the remainder of the anode, providing an electron sink region.
  • a related object is such an anode formed with a phosphor surface.
  • Another related object is such an anode in which the electron sink region is formed integrally in the surface of the anode and is laterally spaced away from the emitting edge of the device's electron emitter.
  • Yet another object is a fabrication process specially adapted for making the improved display device structure.
  • a related object is a fabrication process suitable for simultaneous fabrication of a plurality of individual display devices in an array to form a flat panel display.
  • a device useful as a display element has an electron emitter and an anode disposed to receive electrons emitted from the emitter.
  • the anode has surface portions differing in resistivity, providing an electron sink portion at the surface portion of lowest resistivity.
  • a preferred embodiment has a lateral field-emission electron emitter and has an anode formed by processes specially adapted to provide anode portions of differing resistivity, including the electron sink portion.
  • the electron sink portion is preferably disposed at a position laterally spaced apart from the emitting tip of the device's electron emitter.
  • the anode is formed by depositing a base layer, depositing and patterning an etch-stop layer with an opening to define the electron-sink portion, forming an opening by etching overlying layers down to the etch-stop layer, and heating the base layer and etch-stop layer to form an anode surface that includes both an integral electron-sink portion and a cathodoluminescent phosphor for emitting light.
  • the fabrication process provides for fabricating a plurality of display element devices to make a flat panel display.
  • FIG. 1 shows a side elevation cross-sectional view of a field-emission device made in accordance with the invention.
  • FIG. 2 shows a side cross-sectional view of a field-emission device illustrating electron paths.
  • FIG. 3 shows a flow chart illustrating a preferred process for fabricating the field-emission device of FIG. 1.
  • FIGS. 4a - 4g show a series of side elevation cross-sectional views illustrating results of the steps of the preferred process for fabricating a field-emission device.
  • FIG. 5 shows a side elevation cross-sectional view of an alternate embodiment of a field-emission device made in accordance with the invention.
  • FIG. 1 shows a side elevation cross-sectional view of a field-emission device (generally denoted by reference numeral 10) made in accordance with the invention.
  • the device has a substrate 20.
  • a composite anode 30 receives electrons emitted from a field emitter 40 when suitable bias voltages are applied to the anode and field emitter.
  • Field emitter 40 has an extremely fine tip or edge 50 from which electrons are emitted in accordance with the Fowler-Nordheim electron tunneling phenomenon, when a suitably high electric field is created at the tip 50.
  • An opening 55 extends at least from lateral field emitter 40 down to composite anode 30.
  • Composite anode 30 comprises a layer of base material 35 on the top surface of substrate 20 and a phosphor portion 70 extending along the top surface of composite anode 30 and defining the extent of a lower-resistivity electron-sink portion 80.
  • Electron-sink portion 80 may advantageously be made to have a very small area relative to the area of phosphor portion 70; the relative proportions of regions 70 and 80 in the drawings are not drawn to scale.
  • Substrate 20 is preferably conductive for providing electrical contact to the anode. If an insulating substrate is used, an additional conductive layer (not shown) may be disposed between the insulating substrate and base material layer 35 and may be patterned to provide a buried anode contact (not shown) for applying the anode voltage and for carrying current to external circuitry.
  • Device structures having such buried anode contacts and methods for making such structures are described in U.S. Pat. Nos. 5,644,188 and 5,630,741, the entire disclosure of each of which is incorporated herein by reference.
  • FIG. 1 shows two lateral field emitters 40, and two emitter tips 50, to illustrate the advantage that a dual-emitter device can be made by the same process, with no additional process steps needed for the second emitter.
  • the second emitter is not required for operation of the device, and the second emitter may be omitted. If the second emitter is omitted, electron sink region
  • electron-sink region 80 may be positioned adjacent to the edge of opening 55 furthest from the remaining field emitter tip 50.
  • electron-sink region 80 could advantageously be positioned adjacent to the right edge of opening 55, furthest from the remaining left emitter tip.
  • Lateral field emitter 40 is separated from anode 30 by an insulating layer 60, which supports the lateral field emitter at a predetermined distance above the plane of the anode's top surface.
  • a second insulating layer 90 may be disposed on top of field emitter 40. In principle, omission of second insulating layer 90 could improve viewing angles of the display, but practically the viewing angle improvement tends to be very slight, as only a thin insulating layer 90 is employed.
  • FIG. 1 Device structures made as shown in FIG. 1 have provided an unexpected result: electrons emitted from field-emitter tip 50 do not travel directly into the anode only near emitter tip 50. In this surface electron device, electrons apparently travel across the surface until they reach the lower-resistivity electron-sink region 80, where they enter the bulk material of anode base material 35.
  • the overall beneficial effect is a bright pixel with a large effective fill factor, in which cathodoluminescence occurs not only in the vicinity of emitter tip 50, but also over the whole area of phosphor portion 70 at the bottom of trench opening 55.
  • Means are provided for applying a suitable electrical bias to cause electron field emission from emitting edge 50 to composite anode 30, as known in the art.
  • FIG. 2 shows a side cross-sectional view of a field-emission device, illustrating by dotted lines some electron paths 100 that may be typical in devices made in accordance with the invention. While such electron paths are believed to contribute to the improved performance observed from devices of the present invention, the invention is not intended to be limited by any particular physical phenomenon, but to be defined only by its structures and/or by the methods of its fabrication as set forth in the appended claims.
  • FIG. 3 shows a flow chart illustrating a preferred process for fabricating the field-emission device of FIG. 1.
  • FIGS. 4a - 4g show a series of side elevation cross- sectional views illustrating results of the steps of the preferred process.
  • the preferred process includes the overall steps of providing a substrate (SI), forming an anode having at least one electron sink region on the substrate (S2 - S3, and S8), forming and patterning an electron emitter spaced apart from the anode and at least partially aligned with the anode (S5, S7), and disposing an insulating layer between the anode and the emitter (S4).
  • SI substrate
  • S2 - S3, and S8 an anode having at least one electron sink region on the substrate
  • S5 S7 forming and patterning an electron emitter spaced apart from the anode and at least partially aligned with the anode
  • S4 disposing an insulating layer between the anode and the emitter
  • the first step (SI) is providing a substrate 20, which may be silicon for example.
  • a base layer of a suitable first substance 35 is deposited (FIG. 4a).
  • This first substance 35 is a cathodoluminescent phosphor, or a precursor substance that can be converted to a cathodoluminescent phosphor by heat treatment.
  • a conductive or semiconductive phosphor should be selected, preferably with a resistivity of less than 200 microhm-centimeters.
  • the base layer comprises ZnO:Zn, i.e. zinc oxide doped with excess zinc (in excess of a stoichiometric amount).
  • an etch-stop layer 75 is deposited and patterned (FIG. 4b) to form a first opening 80 that will define the locus of the electron-sink portion.
  • the etch-stop layer 75 may be a refractory metal such as Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, or combinations or alloys of these metals.
  • the etch-stop layer comprises Ta.
  • the depositing and patterning may be accomplished simultaneously by depositing the etch-stop material through a patterned mask.
  • a first insulator layer 60 is deposited (FIG. 4c). This may be a layer of silicon oxide, for example.
  • a thin emitter layer 40 is deposited (FIG.
  • the emitter layer is a layer of Mo of about 300 angstroms thickness.
  • the material of the emitter layer preferably has a low work function.
  • a second insulator layer 90 is deposited if desired (FIG. 4e). This insulating layer 90 may also be of silicon oxide.
  • a second opening 55 through the emitter layer 40 and the first and second insulator layers (60 and 90) is formed by etching, while leaving the etch-stop layer 75 substantially un-etched (FIG. 4f). This etching is preferably performed using a conventional directional etching process such as reactive ion etching, sometimes called "trench etching" in the semiconductor fabrication literature.
  • step S8 (FIG. 4g) the base layer 35 and etch-stop layer 75 are heated to form a phosphor 70 integral to an anode 30 having an electron-sink portion 80 located at the first opening.
  • this heating of the ZnO:Zn base layer substance and the Ta etch-stop layer at a suitable temperature for a suitable time forms the phosphor Ta 2 Zn 3 O 8 .
  • Heating treatments at 900 °C for about one hour or more, or at 1200 °C for about 10 seconds or more, are examples of suitable heating treatments that have been used successfully for forming the phosphor Ta 2 Zn 3 O 8 of the preferred embodiment. This completes the fabrication of the electron field-emission device.
  • This fabrication process provides for fabricating a plurality of display element devices to make a flat panel display, by performing the steps described above simultaneously for as many display devices as needed for the flat panel display, arranged in a suitable array, with the emitter and/or anode electrical contact arranged in a suitable conventional matrix as known in the art.
  • FIG. 5 shows a side elevation cross-sectional view of an alternate embodiment of a field-emission device which has one or more control electrodes or gates (110, 120) for controlling the electron current flowing from emitter edge 50 to anode 30. While FIG. 5 shows two control electrode layers 110 and 120, disposed below and above emitter layer 40 respectively, functional devices may be made with only one control electrode layer (either control electrode layer 110 or control electrode layer 120) omitted. Control electrode layers 110 and 120 are fabricated by depositing and patterning conductive materials over insulating layers 60 and/or 90, and depositing additional suitable insulating layers such as insulating layer 130 as required to insulate the control electrode layers from other conductive elements. Fabrication steps for the control electrodes are not illustrated in FIGS.
  • control electrodes 110 and/or 120 are described in U.S. Pat. Nos. 5,644,188 and 5,630,741, incorporated hereinabove by reference. Means are provided for applying suitable electrical control signals to control electrodes 110 and/or 120.
  • the invention provides a flat panel display having a plurality of display cells, each cell having improved brightness and fill factor.
  • the fabrication processes are specially adapted to provide anode portions of differing resistivity.
  • the fabrication processes provide for simultaneously fabricating a plurality of display element devices to make a flat panel display having improved brightness and fill factor.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Cathode-Ray Tubes And Fluorescent Screens For Display (AREA)

Abstract

Cette invention se rapporte à un dispositif utile en tant qu'élément d'affichage, qui comporte un émetteur d'électrons et une anode disposée de manière à recevoir les électrons émis par l'émetteur. L'anode possède des parties superficielles dotées d'une résistivité différente, la partie superficielle de plus faible résistivité constituant un puits à électrons. Une réalisation préférée possède un émetteur latéral d'électrons à émission par effet de champ et une anode formée selon des procédés spécialement conçus pour former des parties anodiques de résistivité différente, et notamment la partie faisant office de puits à électrons. Cette dernière est de préférence disposée en un emplacement latéralement distant de l'extrémité émettrice de l'émetteur d'électrons du dispositif. Selon un procédé de fabrication particulièrement préféré, on forme l'anode en déposant une couche de base, en déposant et en structurant une couche d'arrêt de l'attaque, dotée d'une ouverture dans le but de définir la partie faisant office de puits à électrons, en formant une ouverture par attaque des couches superposées jusqu'à la couche sous-jacente d'arrêt de l'attaque, et en chauffant la couche de base et la couche d'arrêt de l'attaque de façon à former une surface anodique qui incorpore à la fois une partie puits à électrons et un luminophore cathodoluminescent destiné à émettre de la lumière. L'invention concerne également le processus de fabrication d'une pluralité de dispositifs élémentaires d'affichage permettant la constitution d'un afficheur à panneau plan.
PCT/US1997/023718 1996-12-30 1997-12-30 Dispositif d'affichage electronique a balayage de surface et procede de fabrication WO1998032145A2 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
AU58052/98A AU5805298A (en) 1996-12-30 1997-12-30 Surface electron display device and fabrication process
JP53437898A JP2001525105A (ja) 1996-12-30 1997-12-30 表面電子ディスプレイデバイス、並びにその製造方法
CA002274664A CA2274664A1 (fr) 1996-12-30 1997-12-30 Dispositif d'affichage electronique a balayage de surface et procede de fabrication
EP97954214A EP0948800A2 (fr) 1996-12-30 1997-12-30 Dispositif d'affichage electronique a balayage de surface et procede de fabrication

Applications Claiming Priority (8)

Application Number Priority Date Filing Date Title
US3378896P 1996-12-30 1996-12-30
US3378796P 1996-12-30 1996-12-30
US60/033,787 1996-12-30
US60/033,788 1996-12-30
US08/964,483 1997-11-05
US08/964,987 1997-11-05
US08/964,987 US6015324A (en) 1996-12-30 1997-11-05 Fabrication process for surface electron display device with electron sink
US08/964,483 US5872421A (en) 1996-12-30 1997-11-05 Surface electron display device with electron sink

Publications (2)

Publication Number Publication Date
WO1998032145A2 true WO1998032145A2 (fr) 1998-07-23
WO1998032145A3 WO1998032145A3 (fr) 1998-11-19

Family

ID=27488145

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1997/023718 WO1998032145A2 (fr) 1996-12-30 1997-12-30 Dispositif d'affichage electronique a balayage de surface et procede de fabrication

Country Status (6)

Country Link
EP (1) EP0948800A2 (fr)
JP (1) JP2001525105A (fr)
KR (1) KR20000069815A (fr)
AU (1) AU5805298A (fr)
CA (1) CA2274664A1 (fr)
WO (1) WO1998032145A2 (fr)

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5144191A (en) * 1991-06-12 1992-09-01 Mcnc Horizontal microelectronic field emission devices
US5192240A (en) * 1990-02-22 1993-03-09 Seiko Epson Corporation Method of manufacturing a microelectronic vacuum device
US5214347A (en) * 1990-06-08 1993-05-25 The United States Of America As Represented By The Secretary Of The Navy Layered thin-edged field-emitter device
US5233263A (en) * 1991-06-27 1993-08-03 International Business Machines Corporation Lateral field emission devices
US5382867A (en) * 1991-10-02 1995-01-17 Sharp Kabushiki Kaisha Field-emission type electronic device
US5502314A (en) * 1993-07-05 1996-03-26 Matsushita Electric Industrial Co., Ltd. Field-emission element having a cathode with a small radius
US5530262A (en) * 1992-09-25 1996-06-25 International Business Machines Corporation Bidirectional field emission devices, storage structures and fabrication methods
US5532544A (en) * 1987-07-15 1996-07-02 Ganon Kabushiki Kaisha Electron-emitting device with electron-emitting region insulated from electrodes

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5532544A (en) * 1987-07-15 1996-07-02 Ganon Kabushiki Kaisha Electron-emitting device with electron-emitting region insulated from electrodes
US5192240A (en) * 1990-02-22 1993-03-09 Seiko Epson Corporation Method of manufacturing a microelectronic vacuum device
US5214347A (en) * 1990-06-08 1993-05-25 The United States Of America As Represented By The Secretary Of The Navy Layered thin-edged field-emitter device
US5144191A (en) * 1991-06-12 1992-09-01 Mcnc Horizontal microelectronic field emission devices
US5233263A (en) * 1991-06-27 1993-08-03 International Business Machines Corporation Lateral field emission devices
US5382867A (en) * 1991-10-02 1995-01-17 Sharp Kabushiki Kaisha Field-emission type electronic device
US5530262A (en) * 1992-09-25 1996-06-25 International Business Machines Corporation Bidirectional field emission devices, storage structures and fabrication methods
US5502314A (en) * 1993-07-05 1996-03-26 Matsushita Electric Industrial Co., Ltd. Field-emission element having a cathode with a small radius

Also Published As

Publication number Publication date
AU5805298A (en) 1998-08-07
JP2001525105A (ja) 2001-12-04
KR20000069815A (ko) 2000-11-25
WO1998032145A3 (fr) 1998-11-19
EP0948800A2 (fr) 1999-10-13
CA2274664A1 (fr) 1998-07-23

Similar Documents

Publication Publication Date Title
US5445550A (en) Lateral field emitter device and method of manufacturing same
US7156715B2 (en) Triode structure of field emission display and fabrication method thereof
US6144144A (en) Patterned resistor suitable for electron-emitting device
US5666019A (en) High-frequency field-emission device
WO2006036986A2 (fr) Structure de cathode pour dispositif a emission par effet de champ
US20050236963A1 (en) Emitter structure with a protected gate electrode for an electron-emitting device
US6541906B2 (en) Field emission display panel equipped with a dual-layer cathode and an anode on the same substrate and method for fabrication
US5618216A (en) Fabrication process for lateral-emitter field-emission device with simplified anode
US5872421A (en) Surface electron display device with electron sink
JPH08115654A (ja) 粒子放出装置、電界放出型装置及びこれらの製造方法
US5644190A (en) Direct electron injection field-emission display device
WO1999049492A1 (fr) Afficheur ligne a emission de champ
JP3409468B2 (ja) 粒子放出装置、電界放出型装置及びこれらの製造方法
JP3066573B2 (ja) 電界放出型表示素子
US6015324A (en) Fabrication process for surface electron display device with electron sink
US20040145299A1 (en) Line patterned gate structure for a field emission display
US5442256A (en) Single substrate, vacuum fluorescent display incorporating triode light emitting devices
US5628663A (en) Fabrication process for high-frequency field-emission device
US5616061A (en) Fabrication process for direct electron injection field-emission display device
KR100334017B1 (ko) 평판 디스플레이
WO1998032145A2 (fr) Dispositif d'affichage electronique a balayage de surface et procede de fabrication
WO1996036061A1 (fr) Structure cellulaire d'affichage a emission de champ et procede de fabrication
US6144145A (en) High performance field emitter and method of producing the same
US5811929A (en) Lateral-emitter field-emission device with simplified anode
WO1996042113A1 (fr) Cathode stratifiee composite a emission de champ laterale et son procede de fabrication

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 97180858.9

Country of ref document: CN

AK Designated states

Kind code of ref document: A2

Designated state(s): AU BR CA CN HU JP KP KR MX NO NZ PL RU SG TR UA VN

AL Designated countries for regional patents

Kind code of ref document: A2

Designated state(s): AM AZ BY KG KZ MD RU TJ TM AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE

AK Designated states

Kind code of ref document: A3

Designated state(s): AU BR CA CN HU JP KP KR MX NO NZ PL RU SG TR UA VN

AL Designated countries for regional patents

Kind code of ref document: A3

Designated state(s): AM AZ BY KG KZ MD RU TJ TM AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
ENP Entry into the national phase

Ref document number: 2274664

Country of ref document: CA

Ref document number: 2274664

Country of ref document: CA

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 1997954214

Country of ref document: EP

ENP Entry into the national phase

Ref document number: 1998 534378

Country of ref document: JP

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 1019997005971

Country of ref document: KR

121 Ep: the epo has been informed by wipo that ep was designated in this application
WWP Wipo information: published in national office

Ref document number: 1997954214

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 1019997005971

Country of ref document: KR

WWW Wipo information: withdrawn in national office

Ref document number: 1997954214

Country of ref document: EP

WWW Wipo information: withdrawn in national office

Ref document number: 1019997005971

Country of ref document: KR