US3630587A - Activating method for cesium activated iii-v compound photocathode using rare gas bombardment - Google Patents

Activating method for cesium activated iii-v compound photocathode using rare gas bombardment Download PDF

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Publication number
US3630587A
US3630587A US806192A US3630587DA US3630587A US 3630587 A US3630587 A US 3630587A US 806192 A US806192 A US 806192A US 3630587D A US3630587D A US 3630587DA US 3630587 A US3630587 A US 3630587A
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United States
Prior art keywords
rare gas
cesium
compound
photocathode
cathode
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Expired - Lifetime
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US806192A
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English (en)
Inventor
Siegfried Garbe
Gunter Heinrich August Frank
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US Philips Corp
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US Philips Corp
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Priority claimed from DE19681639363 external-priority patent/DE1639363C3/de
Application filed by US Philips Corp filed Critical US Philips Corp
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    • 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
    • H01J9/12—Manufacture of electrodes or electrode systems of photo-emissive cathodes; of secondary-emission electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/26—Bombardment with radiation
    • H01L21/263—Bombardment with radiation with high-energy radiation
    • H01L21/265—Bombardment with radiation with high-energy radiation producing ion implantation
    • H01L21/2654—Bombardment with radiation with high-energy radiation producing ion implantation in AIIIBV compounds

Definitions

  • the invention relates to a method of manufacturing an electric discharge tube, having a photocathode, the active constituent of which consists of a strongly p-conductive A E,- compound which is activated by an alkali metal or an alkaline earth metal.
  • An A,,,B,-compound is to be understood to mean herein normally an intermetallic compound of one of the elements (A,,,) of the third group of the periodic system, boron, aluminum, gallium, indium on the one hand, with an element B,- of the fifth group of the periodic system, nitrogen, phosphorus, arsenic, antimony on the other hand. Mixed crystals are also included.
  • Such photocathodes were described by J. .l. Scheer and J. van Laar in Solid State Communications" 3, 189-l93, l965.
  • the A B cathode was formed from a monocrystal which was cleaved in vacuo.
  • an electric discharge tube having a photocathode the active constituent of which consists of a strongly p-conductive A E,- compound which is activated by an alkali metal or alkaline earth metal
  • the not yet activated compound in the tube is subjected to a heating process at a temperature of maximally 300 C. for a few hours, after which the surface of the compound is subjected to a bombardment by slow rare gas ions.
  • the temperature during the heating process is chosen to be so low because otherwise oxidation of the compound occurs by released residual gases.
  • the temperature is also low enough to avoid out-diffusion of the doping substance from the compound.
  • various layers of the surface are removed, so that contaminations at the surface, for example, oxides are also removed.
  • the energy of these ions is preferably halved during a second part of the treatment.
  • the energies for argon are then maximally 100 and 50 ev., respectively.
  • the current density of the ion bombardment may be of the order of 30 uA per sq. cm.
  • the reduced energy produces a further removal without the formation of crystal defects.
  • the high yields of the known photocathodes are obtained by activation with, for example, monolayers of cesium.
  • the activation by means of cesium or a different activator may be continued, in a manner already proposed, until the photocurrent reduces again to approximately half. By admitting oxygen, the photoemission is increased again and the activation is repeated a few times in this manner. Often only 80 percent of the maximum yield is obtained.
  • the method is continued until the activation comprises at most 5 to monolayers, while after the said oxygen treatment, a fraction of a monolayer is supplied. Substantially the same yield as in a monolayer is obtained, while the emerging electrons are substantially monoenergetic in contrast with the electrons emitted by a monolayer.
  • the cathodes activated in this manner with various monolayers must be formed at temperatures of 150 to 170 C. for IS to 60 minutes before the fraction of the monolayer is provided. At the same time an improvement of crystal defects in the semiconductor compound is obtained.
  • Reference numeral 1 in the drawing denotes a glass tube with exhaust tube 2 and light entrance window 3.
  • the cathode 4 is a monocrystalline gallium arsenide plate the surface of which has (1 l0) orientation.
  • 5 is a gallium arsenide layer, 10 microns thickness, provided epitaxially on the surface. The layer is doped with 3X10 atoms of zinc per ccm. Making it strongly P-type.
  • 6 is the annular anode for the photocathode, 7 is a gridlike electrode and 8 is a platelike electrode.
  • 9 is a cesium evaporation source. After providing all the electrodes in the tube, it is heated in chlorothene, for degreasing, at 60 C. for 2 minutes. The exhaust tube 2 is then connected to the pump. After evacuation the cathode with the whole tube is heated at 275 C. for 4 hours.
  • Pure argon is then admitted to the tube under a pressure of approximately 5X10 Torr. (Traces of oxygen are removed from the argon by a gettering substance).
  • a discharge is ignited by closing switch 10 and a negative voltage of maximally volt is applied between the electrode 7 and the cathode 4 by closing switch 11 and hence an argon ion current of 30 ua./sq.cm. is drawn to the surface of the cathode 4 for 30 minutes producing the slow rare gas ion bombardment of the photocathode as previously described.
  • the voltage is then reduced by rheostat 12 to 50 volts and current is drawn for another 15 minutes.
  • the cesium source 9 is energized by switch 13 and so much cesium is evaporated from the cesium evaporator 9 already degassed during the heating process until the cathode 4 has approximately a maximum photoemission towards the anode 6. This is measured during the cesium activation step in the usual manner by applying a voltage between the anode 6 and cathode 4 via switch 14 and measuring the current in the external circuit, which is the photocathodes photocurrent, while light is incident thereon from above. Then so much more cesium is evaporated onto the cathode surface 5 until the measured photocurrent is halved.
  • Oxygen of approximately 5X10 Torr is then admitted to the tube 1 for such a period of time until the measured photocurrent again reaches a maximum. This cesium activation treatment and oxidation are repeated a few times until the photocurrent again very nearly reaches its first maximum.
  • the cathode 4 is then heated at for 30 minutes after which cesium is again evaporated from the source 9 in a quantity which corresponds approximately to one-fourth to half of the first cesium addition. This corresponds to the monolayer fraction above described.
  • a method of activating a photocathode within an electric discharge tube comprising a surface of a strongly P-type conductivity compound of an element selected from the group consisting of boron, aluminum, gallium, and indium with an element selected from the group consisting of nitrogen, phosphorus, arsenic, and antimony, and mixed crystals thereof, covered with an activating material of an alkali metal or alkaline earth metal, comprising the steps of heating the unactivated compound within an evacuated tube at an elevated temperature not exceeding 300 C. for several hours, thereafter subjecting the surface of the unactivated compound to slow rare gas ion bombardment with ions whose energy is maximally 100 ev., and thereafter bringing the activating material into contact with the bombarded surface of the compound.
  • the rare gas ion bombardment step comprises a first part using rare gas ions of a given energy, and a later second part using rare gas ions whose energy is approximately half of the said given energy.
  • the surface of the cathode is covered with a fraction of a monolayer of the activating material.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Manufacturing & Machinery (AREA)
  • Computer Hardware Design (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Toxicology (AREA)
  • Health & Medical Sciences (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Common Detailed Techniques For Electron Tubes Or Discharge Tubes (AREA)
  • Electron Sources, Ion Sources (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)
  • Vessels And Coating Films For Discharge Lamps (AREA)
  • Image-Pickup Tubes, Image-Amplification Tubes, And Storage Tubes (AREA)
US806192A 1968-03-15 1969-03-11 Activating method for cesium activated iii-v compound photocathode using rare gas bombardment Expired - Lifetime US3630587A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19681639363 DE1639363C3 (de) 1968-03-15 1968-03-15 Verfahren zum Herstellen von einer elektrischen Entladungsröhre mit einer Photokathode, welche aus einer stark p-leitenden AIII-BV-Verbindung besteht

Publications (1)

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US3630587A true US3630587A (en) 1971-12-28

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Country Status (7)

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US (1) US3630587A (xx)
BE (1) BE729828A (xx)
CH (1) CH489114A (xx)
ES (1) ES364745A1 (xx)
FR (1) FR2004044A1 (xx)
GB (1) GB1207091A (xx)
NL (1) NL6903628A (xx)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3837723A (en) * 1971-11-03 1974-09-24 Galileo Electro Optics Corp Method for making hybrid radiant energy sensor with solid state element and transfer energy-sensitive, electron-emissive surface
US3960421A (en) * 1972-03-27 1976-06-01 U.S. Philips Corporation Method of manufacturing a non-thermally emitting electrode for an electric discharge tube
EP0206422A1 (en) * 1985-06-24 1986-12-30 Koninklijke Philips Electronics N.V. Electron emission device provided with a reservoir containing material reducing the electron work function
CN110706989A (zh) * 2019-10-30 2020-01-17 南京工程学院 提高GaAs光电阴极稳定性的Cs/NF3激活方法
CN112908806A (zh) * 2021-01-16 2021-06-04 南京理工大学 一种电子源封装

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL8500596A (nl) * 1985-03-04 1986-10-01 Philips Nv Inrichting voorzien van een halfgeleiderkathode.
CN111261475B (zh) * 2020-01-29 2022-07-08 北方夜视技术股份有限公司 用于制作光电倍增管的一体式多功能排气装置及使用方法

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1988525A (en) * 1930-11-21 1935-01-22 Emi Ltd Photo-electric tube
US2045637A (en) * 1934-07-26 1936-06-30 Philips Nv Phototube
US2072342A (en) * 1930-06-14 1937-03-02 C M Lab Inc Photoelectric tube
US2206713A (en) * 1929-08-28 1940-07-02 Gen Electric Photoelectric apparatus
US2237242A (en) * 1938-01-05 1941-04-01 Univ Illinois Phototube
US2529888A (en) * 1946-06-29 1950-11-14 Emi Ltd Electron discharge device
US3387161A (en) * 1964-12-02 1968-06-04 Philips Corp Photocathode for electron tubes

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2206713A (en) * 1929-08-28 1940-07-02 Gen Electric Photoelectric apparatus
US2072342A (en) * 1930-06-14 1937-03-02 C M Lab Inc Photoelectric tube
US1988525A (en) * 1930-11-21 1935-01-22 Emi Ltd Photo-electric tube
US2045637A (en) * 1934-07-26 1936-06-30 Philips Nv Phototube
US2237242A (en) * 1938-01-05 1941-04-01 Univ Illinois Phototube
US2529888A (en) * 1946-06-29 1950-11-14 Emi Ltd Electron discharge device
US3387161A (en) * 1964-12-02 1968-06-04 Philips Corp Photocathode for electron tubes

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Photoemissive Materials by Sommer pp. 42 47 and 61 63 (publ. 1968 by John Wiley & Sons). *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3837723A (en) * 1971-11-03 1974-09-24 Galileo Electro Optics Corp Method for making hybrid radiant energy sensor with solid state element and transfer energy-sensitive, electron-emissive surface
US3960421A (en) * 1972-03-27 1976-06-01 U.S. Philips Corporation Method of manufacturing a non-thermally emitting electrode for an electric discharge tube
EP0206422A1 (en) * 1985-06-24 1986-12-30 Koninklijke Philips Electronics N.V. Electron emission device provided with a reservoir containing material reducing the electron work function
CN110706989A (zh) * 2019-10-30 2020-01-17 南京工程学院 提高GaAs光电阴极稳定性的Cs/NF3激活方法
CN112908806A (zh) * 2021-01-16 2021-06-04 南京理工大学 一种电子源封装
CN112908806B (zh) * 2021-01-16 2022-09-20 南京理工大学 一种电子源封装

Also Published As

Publication number Publication date
GB1207091A (en) 1970-09-30
CH489114A (de) 1970-04-15
NL6903628A (xx) 1969-09-17
DE1639363A1 (de) 1970-03-26
DE1639363B2 (de) 1976-03-11
BE729828A (xx) 1969-09-15
FR2004044A1 (xx) 1969-11-14
ES364745A1 (es) 1970-12-16

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