US3127226A - Pin-hole evaporation camera - Google Patents

Pin-hole evaporation camera Download PDF

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US3127226A
US3127226A US3127226DA US3127226A US 3127226 A US3127226 A US 3127226A US 3127226D A US3127226D A US 3127226DA US 3127226 A US3127226 A US 3127226A
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evaporator
photoconductive
monitoring
deposited
evaporation
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    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
    • C23C14/54—Controlling or regulating the coating process
    • C23C14/548—Controlling the composition
    • 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
    • H01J9/20—Manufacture of screens on or from which an image or pattern is formed, picked up, converted or stored; Applying coatings to the vessel
    • H01J9/233—Manufacture of photoelectric screens or charge-storage screens
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S148/00—Metal treatment
    • Y10S148/064—Gp II-VI compounds
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S148/00—Metal treatment
    • Y10S148/065—Gp III-V generic compounds-processing
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S148/00—Metal treatment
    • Y10S148/158—Sputtering
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S148/00—Metal treatment
    • Y10S148/169—Vacuum deposition, e.g. including molecular beam epitaxy

Definitions

  • photoconductive deposit having a maximum sensitivity combined with a minimum photoconductive lag, maximum speed of response, selected spectral response as well as other preferred parameters of the photoconductive deposit.
  • One of the solutions that has been proposed to obtain the photoconductive deposits having these desired properties is the simultaneous use of two or more different photoconductive materials.
  • a photoconductive material including antimony tri-sulfide and antimony oxy-sulfide.
  • the device includes at least two spaced evaporator sources and an aperture positioned in the evaporant stream from both of the evaporators.
  • the aperture By spacing a monitoring plate behind the aperture, separate, clearly defined images of the amount of material being deposited on the selected surface, are also deposited on the monitoring plate.
  • the amount of the different materials deposited on the selected surface can be accurately determined.
  • rates of evaporatron of each component can be adjusted, while. the evaporation is taking place, to obtain any desired composition or graded composition through the thickness of the photoconductor deposit.
  • FIG. 1 is a sectional view of a pickup or camera tube having a target electrode made in accordance with this 1nvention;
  • FIG. 2 is an enlarged fragmentary sectional view of the target electrode shown in FIG. 1;
  • FIG. 3 is an enlarged fragmentary sectional view of another embodiment of a target electrode made in accordance with this invention.
  • FIG. 4 is a partially schematic sectional view of means for obtaining the target electrodes shown in FIGS. 2 and 3 in accordance with this invention.
  • FIG. 5 is a broken away perspective view of an evaporator boat for uses in the means shown in FIG. 4.
  • the pickup tube It is an example of a tube wherein this invention is particularly useful and the invention will be explained in detail in connection with this type of tube.
  • the tube lil comprises an evacuated envelope 12 having an electron gun assembly 14 positioned in one end thereof for producing an electron beam.
  • the electron beam is directed toward and scanned over a photoconductive target electrode lid.
  • the target electrode 18, which is shown more clearly in FIG. 2, comprises a transparent electrically conductive electrode 20 deposited on a transparent face plate 22.
  • the face plate 22 forms an end of the envelope 12.
  • the transparent electrically conductive electrode 20 is made of a material that is selected for its transparency to radiations of the particular wavelengths of interest and for its electrical conductivity. For the visible range of wavelengths, a layer of tin oxide has been found to be suitable.
  • the transparent conductive coating 29 is deposited in contact with an electrically conductive sealing ring 24 so that, during operation of the device 10, an electrical potential may be applied to the transparent conductor 2t and the transparent conductor may function as a signal plate for obtaining output signals from the device 10.
  • the graded composition of photoconductive material 26 comprises a layer 26a of first photoconductive material, a layer 26b of a mixture of the first and of a second photoconductive material, and a layer 26c of the second photoconductive material.
  • the particular chemical compositions selected for the various layers of the graded composition of photoconductive material 26 may be any known chemicals.
  • One example of a graded composition photoconductor is antimony oxysulfide used as the layer 26a, antimony tri-sulfide used as the layer 260, and a mixture of the two for the intermes13 diate layer 26b.
  • a photoconductive target electrode 18 may be constructed with the most desirable optical and electrical properties.
  • the layer 28 of a photoconductive material may be any selected chemical compound or mixture of compounds and may itself be a graded composition.
  • the layer 30' of photoconductive material may also be any selected chemical compound or mixture of compounds and may be the same as or diflerent from the layer 23.
  • Examples of photoconductive materials which may be used in accordance with this invention and which have been deposited in tubes of the type shown in FIG. 1 include the oxides, sulfides, and selenides of antimony, lead, arsenic and cadmium, as well as mixtures of these materials.
  • targets of any number of layers of materials, with each layer being made of one or more chemical compositions, and graded in any desired manner, may be manufactured by using this invention.
  • FIG. 4 An example of a particular means for accurately forming the selected photoconductive layers in accordance with this invention is shown in FIG. 4.
  • two separate face plates 22, 22:: are in the process of having a photoconductive target electrode deposited thereon.
  • the photoconductive materials can be simultaneously deposited onto any number of face plates and two are shown for simplicity of illustration.
  • a transparent electrical conductive coating 20 Prior to the manufacturing step shown in FIG. 4-, a transparent electrical conductive coating 20 has been deposited on each of the face plates 22, 22a, by any known means.
  • the face plates 22, 22a, with their transparent conductive coatings 20, are positioned on a jig 28 and in an evacuated chamber (not shown). Also positioned in the evacuated chamber are at least two spaced apart evaporator boats 30. The structure of the evaporator boats 30 will subsequently be explained in detail in connection with FIG. 5.
  • the jib 2.8 which supports the face plates 22, 22a includes a small, e.g. approximately 0.07 inch aperture 32. Positioned in spaced relation above the aperture 32 is a monitoring plate '34.
  • the jig 28 may be made of a material such as stainless steel while the monitoring plate 34 may be made of any transparent material, one successfully used example of which .is an optically flat transparent glass.
  • the vacuum chamber is evacuated to a relatively high vacuum, e.g. 10* mm. of Hg, for some target materials.
  • a relatively high vacuum e.g. 10* mm. of Hg
  • current is passed through the evaporator boats 30 to heat these boats to a temperature high enough to evaporate the material contained therein.
  • the evaporation process involves essentially a rectilinear propagation of the evaporant.
  • those evaporant molecules coming from an evaporator boat 30 which pass through the aperture 32 land only on a small region or area of the monitoring plate 34, the extent of which is determined primarily by the dimensions of the object source, the size of the aperture and the distance.
  • the image formed on the monitoring plate 34 is, in fact, a geometrical representation of the relative rates of evaporation from various portions of the evaporating area.
  • a long evaporation boat for example, will give a long image; while any hot spots in the evaporation boat will show up as heavier deposits in the corresponding parts of the image.
  • a spacing between boats 30 of 3.3 cm. was used with the boats arranged concentrically around the axis of the aperture 32. With the boats 30 spaced approximately 185 cm. below the aperture and the monitorll ing plate 34 positioned approximately 3.5 cm. above the aperture, the spacing between the deposits of material on the monitoring plate was approximately 6.25 mm.
  • the amount of material deposited on the monitoring plate 34 is proportional to the amount deposited on the tar-get 18.
  • the amount of material comprising each image on the monitoring plate is most conveniently monitored optically.
  • a light source 36 directs light onto both of the photoconductor images and the reflected, or transmitted, light from each is monitored either by an observer or electrically.
  • a light source which has been used as the source 36 is a white fluorescence bulb such as used for ceiling light- .ing fixtures. This offers a fairly continuous light spectrum and, at the distance used, forms a broad area source illuminating the whole of each image on the monitoring plate.
  • the reflection from the image on the monitoring plate shows interference bands, of the deposited material.
  • the interference bands form at the center of the image and expand as separate rings, as the evaporation proceeds.
  • These interference bands, since a white light is used are subtraction colors and occur in the sequence yellow, red, blue. The sequence then proceeds as lY, 1R, 1B, 2Y, 2R, 2B, 3Y, 3R, 3B until the termination of the evaporation.
  • an 83 hand can be detected by the human eye when the material is antimony tri-sulfide. Since the antimony oxy-sulfide is less absorbing, an even greater number of bands can be detected, when using'this material. An examination of the monitoring plate with a hand lens after removal from the vacuum system establishes any doubtful final bands.
  • the first deposit (deposit 28 shown in FIG. 3) was made of antimony oxy-sulfide and was deposited until the fourth order intereference ring was formed. Then, antimony tri-sulfide and antimony oxy-sulfide (corresponding to deposit 30 in FIG. 3) were simultaneously deposited,
  • N is the number of counted interference bands.
  • 11 is the index of refraction of thephotoconductive material (3.5 for antimony tri-sulfide and antimony oxysulfide).
  • 7 ⁇ is the light wavelength in air (0.55 micron).
  • L is the distance from the evaporator boat to the face p ate.
  • L is the distance from the evaporator boat to the monitoring plate.
  • microns .ll2N.
  • FIGURE 5 illustrates a type of evaporator boat which has proved very useful. In an evaporation of two different materials, two such evaporators are used, one for each evaporant.
  • the evaporator boat is directly heated with the ends of the boat 30 clamped to electrical leads (not shown) and current (generally A.C.) passed through the boat.
  • Two evaporant reservoirs are used for symmetry and should be filled with equal amounts of the evaporant.
  • the evaporator is composed of a bottom portion containing reservoirs 38 and vapor channel 39 and a flat lid 37 in the center of which is punched a 0.10" vapor orifice 40.
  • the lid is crimped over the edge of the bottom portion to make the unit vapor tight except for orifice 49.
  • the orifice 40 is large enough to prevent excessive pressure build-up within the evaporator, yet small enough to form approximately a point source for the monitoring system.
  • the evaporator may be formed from .022 tantalum sheet.
  • the monitoring techniques described above provide a knowledge of the amount and composition gradient of a photosurface as it is being deposited. In order to obtain a pre-specified composition gradient, however, it is necessary to control the relative ratio of evaporation of the component evaporands, using the monitored information to detect deviations from the desired gradient. For satisfactory control several functions must be performed, namely (1) monitoring, (2) computing, (3) controlling, and (4) recording. The monitoring function was described previously and may be performed visually or by the use of known electro-optical techniques. Electromechanical equipment (not shown) may be used to perform the functions of controlling and recording as well as certain rudimentary compositions.
  • the evaporation rate, from a boat 30, is a function of the current through the evaporator boat 30. This current may be accurately controlled by means of known variable resistance devices (not shown) in series with the different evaporators and the resistance devices can be controlled so as to either increase or decrease the evaporator current.
  • a tape (not shown) may be pre-punched with current increase and decrease holes, in accordance with a preferred schedule, and run through an electrical sensing device at a constant rate. Electrical relays may be used to operate the resistance devices as the current increase or decrease holes pass through the sensing device. Also, corrections in the preferred schedule may be supplied by the monitor, and applied to the tape, so that if trends in the corrections are noted, in several evaporations, the pre-punched schedules can be modified to reduce the number of corrections necessary during a subsequent evaporation.
  • the observed interference bands may also be recorded on a tape as they occur.
  • the monitor using the interference bands and knowing the preferred schedule, can apply corrections to the preferred schedules to bring the evaporation into line.
  • the monitor then, by his selection of the amount of correction, is serving as a computer.
  • This function can be performed electronically or electro-mechanically with relatively simple circuitry using only the signal output of the interference band differentials.
  • the equipment whose operation is briefly described above, permits satisfactory controlled evaporations to be made by a single operator. By employing electro-optical monitoring, the operation can be made completely automatic. The evaporation could be processed unattended while a complete record of each evaporation was being made.
  • composition graded photosurfaces One of the distinct advantages of some of the composition graded photosurfaces is the high sensitivity of such surfaces.
  • the antimony tri-sulfide, antimony oXy-sulfide photosurface for example, can be made appreciably more sensitive than photosurfaces prepared from either of the components alone.
  • the invention provides a novel method of and means for monitoring the amount and kind of deposit made from a plurality of sources. Since variations may be applied to a preferred schedule, changes that occur in the system, such as a change in vacuum pressure during the evaporation, can be compensated so that the preferred layer may be deposited.
  • the method of depositing a photosensitive surface layer on a support comprising the steps of simultaneously evaporating on said support a photosensitive material from a first evaporator with said first evaporator in a first position and evaporating photosensitive material from a second evaporator with said second evaporator in a second position, positioning a member for receiving material from both of said evaporators, positioning an apertured member for receiving material from both of said evaporators, positioning a monitoring plate on the opposite side of said apertured member from said evaporators for receiving photosensitive material from both said first and second evaporator and passing through the aperture in said apertured member so that said material will land at spaced apart areas on said monitoring surface, and monitoring the amount of photosensitive material deposited on said spaced apart areas.
  • the method of controlling the deposit of photosensitive material on a surface comprising depositing photosensitive material from a first source onto said surface and through an aperture onto a first area of a monitoring member, depositing photosensitive material from a second source onto said surface and through said aperture onto a second area of said monitoring member, said first and said second areas being spaced apart on said monitoring member, and monitoring the amount of material deposited on said monitoring member.
  • a photoconductive pickup tube comprising depositing a transparent conductive coating onto a transparent face plate, evaporating at least one photoconductive material from at least two evaporating boats spaced apart in a given plane and onto said transparent coating, positioning a monitoring means in spaced relation to said plane to receive said photoconductive material from both of said evaporating boats, positioning a member having an aperture therein between said monitoring means and said evaporating boats, whereby said photoconductive material passes through said aperture and is deposited on said monitoring means at spaced apart areas, positioning an electron gun in an envelope, and sealing said face plate with said transparent conductive coating and With the evaporated photoconductive material to said envelope.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physical Vapour Deposition (AREA)
  • Photoreceptors In Electrophotography (AREA)
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US3127226D 1960-10-04 Pin-hole evaporation camera Expired - Lifetime US3127226A (en)

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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3424610A (en) * 1965-10-14 1969-01-28 Us Air Force Vapor depositing infra-sensitive antimony tritelluride
US3620829A (en) * 1968-05-06 1971-11-16 Gen Motors Corp Coatings for germanium semiconductor devices
FR2407565A1 (fr) * 1977-10-27 1979-05-25 Philips Nv Tube d'images en couleur et son procede de fabrication
US4281029A (en) * 1977-03-10 1981-07-28 Toshinori Takagi Method of coating with a stoichiometric compound
US4508931A (en) * 1981-12-30 1985-04-02 Stauffer Chemical Company Catenated phosphorus materials, their preparation and use, and semiconductor and other devices employing them
US4620968A (en) * 1981-12-30 1986-11-04 Stauffer Chemical Company Monoclinic phosphorus formed from vapor in the presence of an alkali metal
US4640720A (en) * 1984-05-14 1987-02-03 U.S. Philips Corporation Method of manufacturing a semiconductor device

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2391280A (en) * 1942-11-26 1945-12-18 Bell Telephone Labor Inc Method of forming layers for electronic cathodes
US2733115A (en) * 1956-01-31 Apparatus for evaporating chemicals
US2744808A (en) * 1952-08-27 1956-05-08 Rca Corp Apparatus for evaporating chemicals
US2871086A (en) * 1956-02-10 1959-01-27 Westinghouse Electric Corp Method for baking and exhausting electron discharge devices
US2871087A (en) * 1956-02-10 1959-01-27 Westinghouse Electric Corp Method of assembling a color television tube
US2881042A (en) * 1955-02-18 1959-04-07 Rca Corp Composite photoconductive layer
DE1057845B (de) * 1954-03-10 1959-05-21 Licentia Gmbh Verfahren zur Herstellung von einkristallinen halbleitenden Verbindungen
US2906637A (en) * 1953-05-19 1959-09-29 Electronique Soc Gen Method of forming a film a short distance from a surface
US2938816A (en) * 1957-06-08 1960-05-31 Siemens Ag Vaporization method of producing thin layers of semiconducting compounds

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2733115A (en) * 1956-01-31 Apparatus for evaporating chemicals
US2391280A (en) * 1942-11-26 1945-12-18 Bell Telephone Labor Inc Method of forming layers for electronic cathodes
US2744808A (en) * 1952-08-27 1956-05-08 Rca Corp Apparatus for evaporating chemicals
US2906637A (en) * 1953-05-19 1959-09-29 Electronique Soc Gen Method of forming a film a short distance from a surface
DE1057845B (de) * 1954-03-10 1959-05-21 Licentia Gmbh Verfahren zur Herstellung von einkristallinen halbleitenden Verbindungen
US2881042A (en) * 1955-02-18 1959-04-07 Rca Corp Composite photoconductive layer
US2871086A (en) * 1956-02-10 1959-01-27 Westinghouse Electric Corp Method for baking and exhausting electron discharge devices
US2871087A (en) * 1956-02-10 1959-01-27 Westinghouse Electric Corp Method of assembling a color television tube
US2938816A (en) * 1957-06-08 1960-05-31 Siemens Ag Vaporization method of producing thin layers of semiconducting compounds

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3424610A (en) * 1965-10-14 1969-01-28 Us Air Force Vapor depositing infra-sensitive antimony tritelluride
US3620829A (en) * 1968-05-06 1971-11-16 Gen Motors Corp Coatings for germanium semiconductor devices
US4281029A (en) * 1977-03-10 1981-07-28 Toshinori Takagi Method of coating with a stoichiometric compound
US4286545A (en) * 1977-03-10 1981-09-01 Futaba Denshi Kogyo K.K. Apparatus for vapor depositing a stoichiometric compound
FR2407565A1 (fr) * 1977-10-27 1979-05-25 Philips Nv Tube d'images en couleur et son procede de fabrication
US4508931A (en) * 1981-12-30 1985-04-02 Stauffer Chemical Company Catenated phosphorus materials, their preparation and use, and semiconductor and other devices employing them
US4620968A (en) * 1981-12-30 1986-11-04 Stauffer Chemical Company Monoclinic phosphorus formed from vapor in the presence of an alkali metal
US4640720A (en) * 1984-05-14 1987-02-03 U.S. Philips Corporation Method of manufacturing a semiconductor device

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GB1001268A (en) 1965-08-11
NL269855A (enrdf_load_stackoverflow)

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