EP0406886B1 - Dispositif de commutation utilisant l'émission par effet de champ et son procédé de fabrication - Google Patents

Dispositif de commutation utilisant l'émission par effet de champ et son procédé de fabrication Download PDF

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Publication number
EP0406886B1
EP0406886B1 EP19900112938 EP90112938A EP0406886B1 EP 0406886 B1 EP0406886 B1 EP 0406886B1 EP 19900112938 EP19900112938 EP 19900112938 EP 90112938 A EP90112938 A EP 90112938A EP 0406886 B1 EP0406886 B1 EP 0406886B1
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EP
European Patent Office
Prior art keywords
switching device
field
emission type
recess
electrode
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP19900112938
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German (de)
English (en)
Other versions
EP0406886A2 (fr
EP0406886A3 (en
Inventor
Masanori Watanabe
Hiroyuki Kado
Takao Chikamura
Nobuyuki Yoshiike
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.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
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Publication date
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Publication of EP0406886A2 publication Critical patent/EP0406886A2/fr
Publication of EP0406886A3 publication Critical patent/EP0406886A3/en
Application granted granted Critical
Publication of EP0406886B1 publication Critical patent/EP0406886B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • 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
    • H01J21/00—Vacuum tubes
    • H01J21/02—Tubes with a single discharge path
    • H01J21/06—Tubes with a single discharge path having electrostatic control means only
    • H01J21/10—Tubes with a single discharge path having electrostatic control means only with one or more immovable internal control electrodes, e.g. triode, pentode, octode
    • H01J21/105—Tubes with a single discharge path having electrostatic control means only with one or more immovable internal control electrodes, e.g. triode, pentode, octode with microengineered cathode and control electrodes, e.g. Spindt-type

Definitions

  • the present invention relates to a super-high-speed switching device using field-emission type cold cathode.
  • Insulation layer 22 is formed on the surface of silicon substrate 21, while gate electrode 24 having a hole 26 of 1-1.5 micrometer diameter and adjacent collector electrode 25 are formed on the insulation layer 22.
  • gate electrode 24 having a hole 26 of 1-1.5 micrometer diameter and adjacent collector electrode 25 are formed on the insulation layer 22.
  • insulation layer 22 is partly remained in a shape of cone, and thereafter, a cone-shaped field-emission type cold cathode (hereinafter referred to as emitter electrode) 23 is formed on the surface of silicon substrate 21. Accordingly, the emitter electrode 23 and the silicon substrate 21 are electrically connected.
  • the switching device according to the prior art is capable of operating at a speed faster than that of the semiconductor switching device by more than one digit place, there is a limit in shortening of the operation time, because the prior art switching device has such a structure that the gate electrode 24 is inserted between emitter electrode 23 and collector electrode 25. In other words, it is quite difficult according to the prior art switching device to make the spacing between the emitter electrode and the collector electrode less than 10 micrometers to shorten the electron-running time.
  • the rate of electron entering into the collector electrode is not always sufficient. Also, there is such defect that electron beam flows into other neighboring switching devices to cause a crosstalk.
  • EP-A-0 260 075 discloses a field-emission type switching device being a vacuum valve device which comprises a substrate formed with an elongated edged channel, a gate electrode formed at the bottom of the recess, an emitter electrode provided over the substrate adjacent one side of the elongated recess, and a collector electrode provided over the substrate adjacent the other side opposite to the one side of the elongated recess.
  • the field-emission type switching device comprises: a substrate means formed with a recess having a straight edge and serrated edge opposite to said straight edge; a gate electrode formed at the bottom of said recess; an emitter electrode provided over said substrate means and having a serrated edge which is slightly off alignment with the serrate edge of said recess so as to provide an emitter overhanging portion overhanging said recess; a collector electrode provided over said substrate means and having a straight edge which is slightly off alignment with the straight edge of said recess so as to provide a collector overhanging portion overhanging said recess.
  • a method for making a field-emission type switching device comprises steps of: (a) forming an insulation layer on a semiconductor substrate layer; (b) forming an electric conductive layer over said insulation layer; (c) etching said electric conductive layer to form an emitter electrode having a serrated edge and a collector electrode having a straight edge; (d) etching said insulation layer through a space between said emitter electrode and collector electrode so as to form a recess in said insulation layer such that an emitter overhanging portion is formed overhanging said recess and, at the same time, a collector overhanging portion is formed overhanging said recess; ( e ) ion injecting at the bottom of said recess into said semiconductor substrate so as to form a gate electrode; and (f) etching said overhanging portions to provide tapered edges.
  • the field-emission type switching device comprises a P-type silicon substrate 1 having a tickness of 300 micrometer and an insulation layer 2 made of silicon oxide film having a tickness of 0.5 micrometer formed on the P-type silicon substrate 1.
  • the insulation layer 2 is partly removed to provide a recess 6.
  • One dege of the recess 6 is straight and other edge opposite to the one edge is serrated.
  • An emitter electrode 3 and a collector electrode 4 which are formed by a tungsten silicide (WSi2) film with a thickness of 0.2 micrometer are provided on insulation layer 2 such that emitter electrode 3 has a serrated edge 7 which is slightly off alignment towards the collector electrode 4 with the serrate edge of the recess 6, and collector electrode 4 has a straight edge which is slightly off alignment towards the emitter electrode 3 with the straight edge of the recess 6.
  • WSi2 tungsten silicide
  • the bottom of groove 6, which is the surface of the silicon substrate 1 is formed with an n+ region by an ion-injection process, thereby defining a gate electrode 5.
  • Figs. 4a-4e steps for forming the field-emission type switching device of Fig. 2 are shown.
  • the insulation layer 2 made of silicon oxide film having 0.3-0.6 micrometer is formed on the surface of P-type silicon substrate 1, and then WSi2 film 9 having a thickness of 0.2 micrometer is formed on the surface of the insulation layer.
  • the emitter electrode 3 and the collector electrode 4 are formed by the step of photolithographic etching, providing 1-3 micrometers, preferably 1.5 micrometers, of spacing between the tip of the serrated edge of emitter electrode 3 and the straight edge of collector electrode 4.
  • the insulation layer 2 between electrodes 3 and 4 is removed by etching process using buffer etching solution, resulting in a formation of recess 6.
  • a peripheral edge portion 3a of emitter electrode 3 and a peripheral edge portion 4a of collector electrode 4 extend over the recess 6 as in eaves.
  • low-resistance n+ layer is formed on the surface of the silicon substrate between both electrodes for making gate electrode 5.
  • a low-resistance p+ layer is formed when an N-type substrate is used.
  • overhanging portions 3a and 4a are etched so as to provide a tapered edge.
  • each pointed tip of the serrated edge 7 is rounded with a curvature radius R of 0.5-1 micrometer, and has a tapered edge thickness T of 0.02-0.04 micrometer.
  • a sharp edge is particularly suitable for the intense and concentrated electrode emission from emitter electrode 3. Since it is very difficult to obtain a sharp edge by reducing the curvature radius R, the sharp edge is obtained by making the tapered edge thickness T very thin.
  • emitter electrode 3 is connected to earth and collector electrode 4 is applied with 60V. At this condition, no electron emits from emitter electrode 3. Then, when gate electrode 5 is provided with 50V pulse, emission of electrons from emitter electrode 3 occurs during the pulse period. Thus, a negative pulse signal is generated at collector electrode 4.
  • emitter electrode 3 is connected to earth and when collector electrode 4 is applied with 80V, emitter electrode 3 emits electrons to cause electron current to flow to collector electrode 4. During such a electron current flow, when gate electrode 5 is applied with -30V pulse voltage, the electron current is cut off during the pulse period.
  • the field-emission type switching device can be used in the same way as the field-effect transistor formed by a semiconductor.
  • the switching device of the present invention can provide less than 0.2 pico-second of the limit of the switching speed as determined by the running time of electron between the emitter and collector electrodes.
  • insulation layer 2 may be formed by such materials as Si3N4, Ta203, or Al203 having a high insulation property. As the thickness of insulation layer 2 is made thinner, the operation becomes more sensitive to the change of voltage in gate electrode 5. Thus, the drive voltage can be lowered.
  • material for forming the emitter electrode is not limited to WSi2, but such material as W, Ta, Mo having high melting point, or carbide such as WC, TaC, ZrC, or SiC, or carbon, may also be used.
  • a field-emission type switching device according to a second embodiment of the present invention is shown.
  • Emitter electrode 12 and collector electrode 13 are formed on the surface of glass substrate 11.
  • a recess 15 is formed in the glass substrate 11 between electrodes 12 and 13.
  • a gate electrode 14 is disposed in recess 15.
  • a distance D1 measured between the tip of emitter electrode 12 and gate electrode 14 is 0.5-1.0 micrometer
  • a distance D2 between the edge of gate electrode 14 and collector electrode 13 is 1-2 micrometers
  • a width W of gate electrode 14 is 0.5-1.0 micrometer.
  • the switching device of the second embodiment operates in the same manner as that of the first embodiment, and similar high speed and stable operation as that observed in the first embodiment is obtained.
  • a level difference between emitter and gate electrodes is 0.5-1.0 micrometer.
  • distance D1 when distance D1 is made shorter than distance D2, it is possible to improved the effect of the gate electrode. Furthermore, by making the distance D2 great, it is possible to increase the dielectric breakdown voltage between both gate and collector electrodes, thus making it possible to provide a switching device having high amplification rate.
  • the switching device according to the present invention may be encapsulated by a suitable casing to provide the switching device in a vacuum condition, or in a non-active gas.
  • the switching speed can be shortened more than one-tenth. Furthermore, no crosstalk occurs between adjacent devices, and yet, the invented switching device can be manufactured at inexpensive cost.

Claims (14)

  1. Dispositif de commutation du type à émission de champ comprenant:
    - un moyen de support (1, 2; 11) formé d'un creux (6; 15);
    - une électrode de grille (5; 14) formée au fond dudit creux (6; 15);
    - une électrode d'émetteur (3; 12) prévue sur ledit moyen de support (1, 2; 11) adjacente à un côté dudit creux (6; 15); et
    - une électrode de collecteur (4; 13) prévue sur ledit moyen de support (1, 2; 11) adjacente à l'autre côté opposé audit côté dudit creux (6; 15); dispositif caractérisé en ce que :
    - ledit creux (6; 15) possède un bord droit et un bord crénelé opposé audit bord droit;
    - ladite électrode d'émetteur (3; 2) possède un bord crénelé qui est légèrement décalé par rapport au bord crénelé dudit creux (6; 15) de façon à constituer une partie d'émetteur en surplomb (3a) surplombant ledit creux (6; 15); et
    - ladite électrode de collecteur (4; 13) possède un bord droit qui est légèrement décalé du bord droit dudit creux (6; 15) de façon à constituer une partie de collecteur en surplomb (4a) surplombant ledit creux (6; 15).
  2. Dispositif de commutation du type à émission de champ selon la revendication 1, dans lequel ledit moyen de support (1, 2) comprend une couche de support (1) constituée d'un matériau semi-conducteur et une couche d'isolation (2) constituée d'un matériau électriquement isolant.
  3. Dispositif de commutation du type à émission de champ selon la revendication 2, dans lequel ladite électrode de grille (5) est formée par un processus d'injection ionique.
  4. Dispositif de commutation du type à émission de champ selon la revendication 1, dans lequel ladite électrode de grille (14) est formée d'un film en métal.
  5. Dispositif de commutation du type à émission de champ selon la revendication 1, dans lequel ladite partie d'émetteur en surplomb (3a) est inclinée vers son extrémité.
  6. Dispositif de commutation du type à émission de champ selon la revendication 5, dans lequel ledit bord incliné possède un rayon de courbure compris entre 0,5 et 1,0 µm.
  7. Dispositif de commutation du type à émission de champ selon la revendication 5, dans lequel ledit bord incliné possède une épaisseur comprise entre 0,02 et 0,04 µm.
  8. Dispositif de commutation du type à émission de champ selon la revendication 1, dans lequel une distance séparant l'électrode d'émetteur (3, 12) et l'électrode de collecteur (4, 13) est comprise entre 1 et 3 µm.
  9. Dispositif de commutation du type à émission de champ selon la revendication 2, dans lequel ladite couche d'isolation (2) possède une épaisseur comprise entre 0,3 et 0,6 µm.
  10. Dispositif de commutation du type à émission de champ selon la revendication 4, dans lequel ladite électrode de collecteur (13) et ladite électrode de grille (14) sont espacées d'une distance supérieure à l'espacement entre l'électrode d'émetteur (12) et ladite électrode de grille (14).
  11. Dispositif de commutation du type à émission de champ selon la revendication 4, dans lequel ladite électrode d'émetteur (12) et ladite électrode de grille (14) sont espacées d'une distance comprise entre 0,5 et 1,0 µm.
  12. Dispositif de commutation du type à émission de champ selon la revendication 4, dans lequel ladite électrode de collecteur (13) et ladite électrode de grille (14) sont espacées d'une distance comprise entre 1 et 2 µm.
  13. Dispositif de commutation du type à émission de champ selon la revendication 4, dans lequel ladite électrode d'émetteur (12) et ladite électrode de grille (14) sont à différents niveaux avec une différence de niveaux comprise entre 0,5 et 1,0 µm.
  14. Procédé de fabrication d'un dispositif de commutation du type à émission de champ comprenant les étapes suivantes :
    (a) la formation d'une couche d'isolation (2) sur une couche de support de semi-conducteur (1);
    (b) la formation d'une couche conductrice (9) sur ladite couche d'isolation (2);
    (c) l'attaque chimique de ladite couche conductrice (9) pour former une électrode d'émetteur (3) possédant un bord crénelé et une électrode de collecteur (4) possédant un bord droit;
    (d) l'attaque chimique de ladite couche d'isolation (2) dans un espace séparant ladite électrode d'émetteur (3) et ladite électrode de collecteur (4) de façon à former un creux dans ladite couche d'isolation (2) de telle façon qu'une partie d'émetteur en surplomb (3a) soit formée au dessus dudit creux (6; 15) et, en même temps, qu'une partie de collecteur en surplomb (4a) soit formée au dessus dudit creux (6; 15);
    (e) l'injection ionique au fond dudit creux (6) dans ledit support de semi-conducteur (1) de façon à former une électrode de grille (5); et
    (f) l'attaque chimique desdites parties en surplomb (3a, 4a) pour former des bords inclinés.
EP19900112938 1989-07-07 1990-07-06 Dispositif de commutation utilisant l'émission par effet de champ et son procédé de fabrication Expired - Lifetime EP0406886B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP175900/89 1989-07-07
JP1175900A JPH0340332A (ja) 1989-07-07 1989-07-07 電界放出型スウィチング素子およびその製造方法

Publications (3)

Publication Number Publication Date
EP0406886A2 EP0406886A2 (fr) 1991-01-09
EP0406886A3 EP0406886A3 (en) 1991-03-27
EP0406886B1 true EP0406886B1 (fr) 1994-12-14

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EP19900112938 Expired - Lifetime EP0406886B1 (fr) 1989-07-07 1990-07-06 Dispositif de commutation utilisant l'émission par effet de champ et son procédé de fabrication

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EP (1) EP0406886B1 (fr)
JP (1) JPH0340332A (fr)
DE (1) DE69015024T2 (fr)

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JP2968014B2 (ja) * 1990-01-29 1999-10-25 三菱電機株式会社 微小真空管及びその製造方法
US5267884A (en) * 1990-01-29 1993-12-07 Mitsubishi Denki Kabushiki Kaisha Microminiature vacuum tube and production method
US5214346A (en) * 1990-02-22 1993-05-25 Seiko Epson Corporation Microelectronic vacuum field emission device
US5192240A (en) * 1990-02-22 1993-03-09 Seiko Epson Corporation Method of manufacturing a microelectronic vacuum device
JP2574500B2 (ja) * 1990-03-01 1997-01-22 松下電器産業株式会社 プレーナ型冷陰極の製造方法
JP2613669B2 (ja) * 1990-09-27 1997-05-28 工業技術院長 電界放出素子及びその製造方法
DE69209336T2 (de) * 1991-01-28 1996-11-14 Sony Corp Mikroelektronischer ballistischer Transistor und Verfahren zu seiner Herstellung
GB2259184B (en) * 1991-03-06 1995-01-18 Sony Corp Flat image-display apparatus
GB2254486B (en) * 1991-03-06 1995-01-18 Sony Corp Flat image-display apparatus
JP3235172B2 (ja) * 1991-05-13 2001-12-04 セイコーエプソン株式会社 電界電子放出装置
JP2763219B2 (ja) * 1991-12-03 1998-06-11 シャープ株式会社 電界放出型電子素子
US5382867A (en) * 1991-10-02 1995-01-17 Sharp Kabushiki Kaisha Field-emission type electronic device
JP2846988B2 (ja) * 1991-12-27 1999-01-13 シャープ株式会社 電界放出型電子放出源素子
KR970000963B1 (ko) * 1992-12-22 1997-01-21 재단법인 한국전자통신연구소 광게이트를 갖는 진공 트랜지스터 및 그 제조방법
JP3599765B2 (ja) * 1993-04-20 2004-12-08 株式会社東芝 陰極線管装置
JPH07254354A (ja) * 1994-01-28 1995-10-03 Toshiba Corp 電界電子放出素子、電界電子放出素子の製造方法およびこの電界電子放出素子を用いた平面ディスプレイ装置
JPH0850850A (ja) * 1994-08-09 1996-02-20 Agency Of Ind Science & Technol 電界放出型電子放出素子およびその製造方法
CN1128461C (zh) 1998-03-21 2003-11-19 韩国科学技术院 双板型扁平场发射显示器
KR20010075311A (ko) * 1999-07-26 2001-08-09 어드밴스드 비젼 테크놀러지스 인코포레이티드 절연-게이트 전자의 전계 방출 소자 및 그 제작 공정
WO2001008193A1 (fr) * 1999-07-26 2001-02-01 Advanced Vision Technologies, Inc. Dispositif a effet de champ a vide et procede de fabrication
KR100658666B1 (ko) * 2001-02-16 2006-12-15 삼성에스디아이 주식회사 카본 나노튜브 에미터를 갖는 전계 방출 표시소자

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Also Published As

Publication number Publication date
JPH0340332A (ja) 1991-02-21
DE69015024D1 (de) 1995-01-26
EP0406886A2 (fr) 1991-01-09
EP0406886A3 (en) 1991-03-27
DE69015024T2 (de) 1995-07-27

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