EP0424422A1 - Element de tunnel de josephson en oxyde metallique supraconducteur et son procede de fabrication - Google Patents

Element de tunnel de josephson en oxyde metallique supraconducteur et son procede de fabrication

Info

Publication number
EP0424422A1
EP0424422A1 EP89907697A EP89907697A EP0424422A1 EP 0424422 A1 EP0424422 A1 EP 0424422A1 EP 89907697 A EP89907697 A EP 89907697A EP 89907697 A EP89907697 A EP 89907697A EP 0424422 A1 EP0424422 A1 EP 0424422A1
Authority
EP
European Patent Office
Prior art keywords
layer
substrate
tunnel element
crystal structure
josephson tunnel
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.)
Withdrawn
Application number
EP89907697A
Other languages
German (de)
English (en)
Inventor
Gabriel Daalmans
Bernhard Roas
Hans Eckhardt Hoenig
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.)
Siemens AG
Original Assignee
Siemens AG
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
Application filed by Siemens AG filed Critical Siemens AG
Publication of EP0424422A1 publication Critical patent/EP0424422A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • 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
    • C23C14/225—Oblique incidence of vaporised material on substrate
    • 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
    • C23C14/0021—Reactive sputtering or evaporation
    • 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
    • C23C14/04—Coating on selected surface areas, e.g. using masks
    • C23C14/042—Coating on selected surface areas, e.g. using masks using masks
    • 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
    • C23C14/04—Coating on selected surface areas, e.g. using masks
    • C23C14/042—Coating on selected surface areas, e.g. using masks using masks
    • C23C14/044—Coating on selected surface areas, e.g. using masks using masks using masks to redistribute rather than totally prevent coating, e.g. producing thickness gradient
    • 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
    • C23C14/24—Vacuum evaporation
    • C23C14/28—Vacuum evaporation by wave energy or particle radiation
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N60/00—Superconducting devices
    • H10N60/01—Manufacture or treatment
    • H10N60/0268—Manufacture or treatment of devices comprising copper oxide
    • H10N60/0296—Processes for depositing or forming copper oxide superconductor layers
    • H10N60/0521—Processes for depositing or forming copper oxide superconductor layers by pulsed laser deposition, e.g. laser sputtering
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N60/00—Superconducting devices
    • H10N60/01—Manufacture or treatment
    • H10N60/0912—Manufacture or treatment of Josephson-effect devices
    • H10N60/0941—Manufacture or treatment of Josephson-effect devices comprising high-Tc ceramic materials
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N60/00—Superconducting devices
    • H10N60/10—Junction-based devices
    • H10N60/12—Josephson-effect devices
    • H10N60/124—Josephson-effect devices comprising high-Tc ceramic materials

Definitions

  • the invention relates to a Josephson tunnel element with a sandwich-like layer structure on a flat side of a substrate, which element
  • a layer made of a metal oxide superconductor material with a predetermined crystal structure serving as a base electrode in a first plane a layer made of the superconductor material serving as a counter electrode with the predetermined crystal structure in a further plane parallel to the first plane and
  • the invention contains a barrier layer arranged between the electrode layers and acting as a tunnel barrier and consisting of a metal oxide, non-superconducting material with a crystal structure adapted to the crystal structure of the superconducting material.
  • the invention further relates to a method for producing such a Josephso ⁇ tunnel element.
  • a corresponding element with the features mentioned and a method for its production are known from US Pat. No. 4,316,785.
  • Josephson tunnel elements with a sandwich-like structure represent a special type of Josephson element. They generally contain a layered base electrode made of superconducting material, on which a thin barrier layer made of an insulating, semiconducting or normally conducting material is applied. This barrier layer forms a tunnel barrier between the base electrode and one on the barrier layer 2 deposited counter electrode, which is also made of superconducting material.
  • the tunnel barrier layer represents a so-called "weak link", ie a zone of weak coupling between the electrode layers (cf., for example, "Proc. IEEE", Vol. 61, No. 1, Jan. 1973, pages 36 to 45) .
  • the Josephson tunnel element which can be gathered from the above-mentioned US PS, also has a corresponding structure.
  • the material of the two electrodes of this element serves su ⁇ pra technicallyde material BaPb 1 _ ⁇ ⁇ 0 3 Bi (having 0.05 - ⁇ x ⁇ 0.3) with perovskite crystal structure and a critical temperature T of about 13 K.
  • the tunnel barrier layer thereby made of a non-superconducting material which also has a corresponding perovskite-like crystal structure. Mechanical stresses during temperature changes are thus to be prevented in the element.
  • a known material system for this metal oxide compound is of the Mel-Me2-Cu-0 type, the components Mel at least containing a rare earth metal or Y and Me2 containing an alkaline earth metal. Films or thin layers of these metal oxide compounds are often produced using special vapor deposition or sputtering processes.
  • a polycrystalline or amorphous precursor with the components of the selected material system is generally deposited on a suitable substrate, the oxygen content and thus the desired superconducting high-T phase not yet being set exactly. This preliminary product is then subjected to heat and oxygen treatment. tion converted into the material with the desired superconducting phase.
  • the superconducting so to be obtained metal oxide whose crystal structures may be similar to a Perowskites have, in the case of YBa 2 CU j 0. 7 (with 0 ⁇ _. 'X' 0,5) is a orthorhombic structure (see. Eg " Europhysics Letters ", Vol. 3, No. 12, June 15, 1987, pages 1301 to 1307). Their junction temperature T is around 90 K. Since the materials having these superconducting phases are to be classed as oxide ceramics, the high-voltage superconductor is often also referred to as oxide-ceramic superconductor
  • a Josephson tunnel element using such an oxide ceramic high-T superconductor material is published in the publication "Japanese Journal of Applied Physics", vol. 26, no. September 9, 1987, Part 2 - Letters, pages L1443 to L1444.
  • This element contains a base electrode layer made of the same material on a sintered substrate of the Y-Ba-Cu-0 material system.
  • An Nb layer applied to the tunnel barrier layer serves as the counter electrode. It turns out, however, that this known Josephson tunnel element at 77 K cannot meet the requirements to be raised for use in active electronic circuits with regard to sufficient critical current density and low magnetic flux noise.
  • Films made of oxide-ceramic high-T superconductor material with high critical current densities are known per se. For this purpose, these films must have at least a textured structure. They show a strongly anisotropic behavior of their critical current density (current carrying capacity) depending on the position the crystal axes.
  • the production of corresponding YBa 2 Cu, 0 7 films on a single-crystalline SrTiO, substrate is described, for example, in "Physical Review Letters", Vol. 58, No. 25, June 22, 1987, pages 2684 to 2686.
  • an annealing treatment at a high temperature of about 900 ° C. is required.
  • Correspondingly produced films can have critical current densities of more than 10 A / cm 2 perpendicular to the c-axes of their crystals at 77 K, while parallel to the c-axes the critical current density is at least one 10-fold lower.
  • a target material of the corresponding material system is first evaporated by means of a laser and deposited on a single-crystal SrTiO ⁇ substrate.
  • the laser to be used can be a KrF excimer laser, the wavelength of which is in the UV spectral range and enables an energy density on the target material of approximately 2 J / cm 2 at a pulse frequency of 3 to 6 Hz.
  • the substrate should be heated to 450 ° C (see also "Appl.Phys.Lett.”, Vol. 51, No. 8, August 24, 1987, pages 619 to 621).
  • a final heat treatment at about 900 ° C. in an oxygen atmosphere and subsequent slow cooling are necessary.
  • the object of the present invention is therefore a
  • the Josephson tunnel element in which these problems are at least largely avoided.
  • the element should be able to be produced using a method with which critical current densities in the superconducting layers of at least 10 A / cm 2 can be formed in a reproducible manner.
  • the electrode layers each consist of an oxide-ceramic superconductor material with a high transition temperature and with an ordered crystal structure, so that the electrode layers have a high critical current density in the direction of the planes point, and that a substrate is provided which has a texture adapted to the crystal structure dimensions of the superconducting phase of the oxide-ceramic superconductor material.
  • the invention therefore takes into account the special crystal structure of the superconducting oxide-ceramic high-T phase to form a Josephson tunnel element.
  • This crystal structure can advantageously be obtained on a correspondingly textured substrate. Accordingly, the two electrode layers of high critical current density are spaced apart by a thin barrier layer, which represents a tunnel barrier that only weakly couples these layers.
  • the predetermined crystal structure of this tunnel barrier facilitates the formation of the counter electrode layer with a high critical current density.
  • Such a Josephson tunnel element can thus vor ⁇ geous meet the desired requirements in terms of critical current density * and low noise.
  • the Josephson tunnel element according to the invention can be produced particularly advantageously by first applying a shadow mask with the hole structure adapted to the tunnel element to be produced in a lithography process on the substrate, and then, in the case of uninterrupted vacuum conditions, the layers of the tunnel element by oblique vapor deposition with simultaneous heat treatment and oxygen treatment, the desired superconducting phase of the superconductor material being formed.
  • a target material made of an oxide ceramic of this material is advantageously vaporized by means of a pulsed laser, the wavelength of which lies in the ultraviolet spectral range.
  • the desired superconducting phase can be crystallized virtually “in situ” and therefore no subsequent formation of this phase by means of a special annealing step at very high temperatures .
  • Higher substrate temperatures and activated oxygen on the substrate are required for the in situ crystallization according to the invention.
  • a laser with a relatively high pulse energy can advantageously be used to activate the oxygen.
  • the molecular oxygen of the intended atmosphere is then activated by interaction with the UV laser radiation directly on the heated substrate with each laser pulse.
  • the amount of oxygen radicals generated in the process and the higher substrate temperature are sufficient to epitaxially grow an approximately 1 nm thick layer with each pulse.
  • the high growth rates that can be achieved at conventional pulse frequencies ensure a short evaporation time and a low contamination of the layers.
  • FIG. 1 schematically illustrates the manufacture of a Josepshon tunnel element.
  • Figure 2 shows schematically an apparatus for performing this method. Corresponding parts in the figures are provided with the same reference numerals.
  • the Josephson tunnel element according to the invention is to be formed from a certain superconducting high-T material on a predetermined substrate.
  • a material from the material system Mel-Me2-Cu-0 is selected as an exemplary embodiment.
  • Mel and Me2 can in particular be an element from the group of rare earth metals such as Y or an element from the group of alkaline earth metals such as Be Ba.
  • materials suitable for Mel and Me2 are generally known.
  • Mel and Me2 are also alloys or compounds or other compositions of these metals with substitution materials; i.e. at least one of the elements mentioned can be partially substituted by another element in a known manner.
  • the Cu or the 0 can also be exchanged at least partially for other elements.
  • the Josephson tunnel element according to the invention and the method for its production are not only limited to the material system mentioned; i.e., other oxide-ceramic, metallic components and oxygen-containing high-T superconductor materials that are not part of the system mentioned are equally suitable.
  • Corresponding materials are e.g. from "Superconductivity News", Vol. 1, No. 9, March 19, 1988, pages 1 to 5 and 13 to 16 are known. The one from the particular
  • High-T superconductor electrode layers to be manufactured of the Josephson tunnel element should enable a high current carrying capacity (critical current density) of the order of magnitude of at least 10 A / cm 2 in the vicinity of the transition temperature T of the material. Also particularly advantageous are those materials whose transition temperature is significantly above the vaporization temperature of the liquid nitrogen of about 77 K.
  • Materials to be selected for the substrate are advantageously those which have a structure with dimensions of their unit cells, which make up at least approximately one or more times the corresponding dimensions of the axes of the structures of the superconducting high-T material grown on them.
  • a single-crystal or at least textured SrTiO, or (Ba, Sr) TiO, substrate is particularly advantageous in the case of YBa 2 Cu, 0y_.
  • other materials such as MgO, A1 2 0- ,, Y-stabilized Zr0 2 or Ta 2 0 c are also suitable.
  • the Josephson tunnel element according to the invention is not necessarily limited to such textured substrates.
  • polycrystalline substrates such as polycrystalline SrTiO applied on a suitable support can also be provided.
  • the formation according to the invention of at least one Josephson tunnel element with a superconducting material of the known composition YBa 2 Cu, 0 7 with an orthorhombic structure on a textured SrTiO ⁇ substrate is used as a basis.
  • a structure is provided, which is illustrated schematically in FIG. 1 as a cross section.
  • a special shadow mask technique which is referred to as a floating mask technique, is advantageously used to produce the at least one Josephson tunnel element.
  • Such Levitation mask technology is generally known (cf., for example, DE-PS 31 28 982 or the publication "SQUID '80 - Supercon ⁇ dueting Quantum Interference Devices and their Applications", Berlin 1980, pages 399 to 415).
  • a floating mask 3 which is matched to the desired Josephson tunnel element structure is first applied to the substrate 2, the texture of which is to be indicated by dashed lines 2a.
  • This floating mask which consists of SiO, for example, has a self-supporting film bridge 3a which hovers above the substrate at a height h of a few micrometers and has a span w of approximately 1 ⁇ m.
  • the uncovered parts of the substrate surface 5 are now freed of all residues, for example by ion bombardment at suitable angles.
  • the substrate, including the floating mask 3 applied to it, is then "in situ", ie without interrupting the vacuum conditions to be provided for the ion bombardment, in oxygen.
  • the layers serving as electrodes must ensure a high critical current density in the direction of their layer planes. Because of the anisotropy of the known high-T superconductor materials, it is necessary for this that the superconducting electrode layers are textured in such a way that the c-axes of their crystal structures are perpendicular to the substrate surface 5. In this direction the critical current density is much smaller than perpendicular to it.
  • the c-axes are indicated in the figure by individual arrowed lines 6.
  • a special laser evaporation technique can be used. Accordingly, a first layer 7 made of the superconductor material is evaporated obliquely onto the heated substrate 2.
  • a pulsed excimer laser is advantageously used, which enables a sufficient energy density and pulse energy.
  • the steam jet 9 is intended to impinge at an evaporation angle c ⁇ which is inclined by approximately 45 ° with respect to the plane of the substrate surface 5. In this way, the area of the substrate surface 5 lying under the floating bridge 3a is also coated.
  • the layer thickness d of the layer 7 lying in a first plane E 1 can, for example, be of the order of magnitude of approximately 100 nm.
  • the first layer obtained in this way represents the base electrode BE of the Josephson tunnel element to be produced, to which a very thin barrier layer 10 is now applied in situ.
  • This layer which acts as a tunnel barrier and has a layer thickness c of a few nm, which is typical for a weak coupling, is advantageously to be produced from a non-superconducting material whose crystal structure is matched to that of the superconducting material.
  • a suitable material is, for example, a Pr-Ba-Cu oxide ceramic.
  • This oxide ceramic is vapor-deposited using the same technique as the superconducting material of layer 7 from the opposite direction at an evaporation angle (180-3).
  • the corresponding steam jet is designated 11 in the figure.
  • a slightly flatter vapor deposition angle is expediently chosen; ie, the following applies: [ ⁇ C
  • an area of the base electrode BE remains free for later contacting; on the other hand clean flank 7 'of the base electrode is also achieved.
  • a second layer 12 made of the superconductor material and serving as counterelectrode GE is then also applied to this structure obtained with the base electrode BE and the barrier layer 10 and reaching up to a parallel plane E2, likewise by epitaxial laser deposition.
  • a vapor deposition angle (180 - oi,) is expediently provided for the corresponding steam jet 13.
  • the thickness D of the second layer 12 should be significantly (at least 1.5 times) greater than the thickness d of the first layer 7. In this way, the required high critical current density can also be ensured in the area of the flank 7 1 via the step of the layer 12 thus formed.
  • the electrodes of the Josephson tunnel element produced in this way, generally designated 15, must be contacted with connecting conductors.
  • the high critical current densities required must also be guaranteed in the contact area.
  • an epitaxial deposition is also provided for the connection conductors, as for the superconducting layers of the electrodes of the Josephson tunnel element 15.
  • parts of the connecting conductors 16 and 17 are formed simultaneously with the electrodes owing to the selected dimensions of the floating mask and the selected vapor deposition angle.
  • FIG. 2 This figure schematically shows a cross section through a corresponding, generally 20 illustrated deposition device illustrated at the time of formation of the layer of the base electrode.
  • the separating device contains a vacuum chamber 21 which is to be evacuated at a pump nozzle 22 by means of a corresponding pump to a final pressure which is, for example, below 10 " bar.
  • a laser beam 25 enters the quartz window 24 of the vacuum chamber 21 Chamber and arrives there at an angle of, for example, about 45 "on a first target 26 made of the desired high-T superconductor material.
  • the target attached to a holder 27 is located in the center of the chamber. It can be exchanged with the aid of a rotatable linkage 28 against a correspondingly held target 26 "made of the non-superconducting material of the tunnel barrier. If necessary, the target exposed to the laser beam can also be moved in order not only to strike the beam
  • the vaporized material is emitted perpendicularly to the target surface as a steam jet 9 from the target 26. It strikes the substrate 2, which is located opposite the target 1, but is not shown in detail in Figure 2.
  • the substrate can advantageously be kept at an elevated temperature level during the vapor deposition process the inclination of the substrate carrier 30 and thus of the substrate relative to the axis of the steam jet 9 adjustable by means of a correspondingly designed linkage, so as to obtain the various evaporation angles.
  • the linkage 31 enables the distance a between the target 26 and the substrate 2 to be varied set a distance a between 20 mm and 45 mm. If necessary, the linkage 31 can also be designed to be rotatable. Adjust any oxygen partial pressure p (0 2 ) via a gas inlet 32.
  • a pulsed laser with a wavelength X of its radiation 25, which lies in the UV spectral range is advantageously provided.
  • the wavelength range of interest extends from approximately 110 nm to 400 nm.
  • the laser must be able to produce an energy density on the material of the target 26 which is above 3 J / cm 2 .
  • the pulse energy of the laser should be at least 1.5 J / pulse.
  • the structure obtained in this way is subjected to an additional oxygen treatment in order to carry out a fine adjustment (loading) of oxygen in the crystal structure of the superconducting layers.
  • the oxygen can be supplied as a gas or ion stream. This treatment can be used advantageously with relatively low temperatures, especially below 600 ° C. If necessary, special heating can even be dispensed with.
  • the layers of the Josephson tunnel element according to the invention are produced by means of an evaporation step using a laser, the heat treatment and the oxygen treatment to form the desired superconducting metal oxide phase taking place simultaneously.
  • a method can be regarded as particularly advantageous. If necessary, however, other methods can also be used which enable the individual layers to be made in-sir, without requiring too high temperature treatments, which lead to an undesired interaction of the materials to be provided for the mask with the lead selected superconductor material.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Manufacturing & Machinery (AREA)
  • Ceramic Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Superconductor Devices And Manufacturing Methods Thereof (AREA)

Abstract

Un élément de tunnel de Josephson (15) à structure en sandwich sur un substrat (2) comprend une couche (7) qui sert d'électrode de base (BE), une couche (12) qui sert de contre-électrode (GE) et une couche (10), agencée entre les couches électrode, qui sert de barrière de tunnel. Les couches électrode (7, 12) sont composées d'un matériau supraconducteur en céramique oxydée dont le point de changement brusque de la conductivité est élevé et la structure cristalline est ordonnée, de sorte que les couches électrode (7, 12) présentent une densité critique de courant élevée dans le sens de leurs strates (E1, E2). La couche barrière de tunnel (10) et le substrat (2) présentent une texture (2a) adaptée aux dimensions de la structure cristalline de la phase supraconductrice du matériau supraconducteur. On produit avantageusement un élément correspondant de tunnel de Josephson par une technique de métallisation oblique sous vide au moyen d'un masque perforé, accompagnée d'un traitement thermique et d'un traitement à l'oxygène.
EP89907697A 1988-07-06 1989-07-03 Element de tunnel de josephson en oxyde metallique supraconducteur et son procede de fabrication Withdrawn EP0424422A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3822905A DE3822905A1 (de) 1988-07-06 1988-07-06 Josephson-tunnelelement mi metalloxidischem supraleitermaterial und verfahren zur herstellung des elements
DE3822905 1988-07-06

Publications (1)

Publication Number Publication Date
EP0424422A1 true EP0424422A1 (fr) 1991-05-02

Family

ID=6358100

Family Applications (1)

Application Number Title Priority Date Filing Date
EP89907697A Withdrawn EP0424422A1 (fr) 1988-07-06 1989-07-03 Element de tunnel de josephson en oxyde metallique supraconducteur et son procede de fabrication

Country Status (3)

Country Link
EP (1) EP0424422A1 (fr)
DE (1) DE3822905A1 (fr)
WO (1) WO1990000815A1 (fr)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE59203408D1 (de) * 1991-01-21 1995-10-05 Siemens Ag Verfahren zur Herstellung eines strukturierten Aufbaus mit Hochtemperatursupraleitermaterial.
DE4124773C2 (de) * 1991-07-26 1996-10-10 Forschungszentrum Juelich Gmbh Josephson-Element aus supraleitender Keramik mit perowskitähnlicher Struktur und Verfahren zu seiner Herstellung
DE4302769C2 (de) * 1993-02-01 1995-11-02 Daimler Benz Ag Verfahren zur Herstellung von Josephson- und Tunnelkontakten aus Hochtemperatur-Supraleitern
US11950516B2 (en) 2018-03-23 2024-04-02 University Of Copenhagen Method and substrate for patterned growth on nanoscale structures

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4316785A (en) * 1979-11-05 1982-02-23 Nippon Telegraph & Telephone Public Corporation Oxide superconductor Josephson junction and fabrication method therefor
DE3128982C2 (de) * 1981-07-22 1985-12-12 Siemens AG, 1000 Berlin und 8000 München Verfahren zur Herstellung mindestens eines Josephson-Tunnelelementes
KR910002311B1 (ko) * 1987-02-27 1991-04-11 가부시기가이샤 히다찌세이사꾸쇼 초전도 디바이스
FR2626715B1 (fr) * 1988-02-02 1990-05-18 Thomson Csf Dispositif en couches minces de materiau supraconducteur et procede de realisation
JPH0284782A (ja) * 1988-05-11 1990-03-26 Canon Inc ジョセフソン素子の製造方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9000815A1 *

Also Published As

Publication number Publication date
WO1990000815A1 (fr) 1990-01-25
DE3822905A1 (de) 1990-01-11
DE3822905C2 (fr) 1992-12-17

Similar Documents

Publication Publication Date Title
EP0341520B1 (fr) Méthode de fabrication d'une couche mince d'oxyde métallique supraconducteur par évaporation au moyen d'un laser
EP0302354B1 (fr) Procédé pour la préparation d'une structure laminée à partir d'un matériau supraconducteur d'oxyde céramique
DE60319470T2 (de) Herstellungsverfahren für einen polykristallinen Dünnfilm und Herstellungsverfahren für ein Oxidsupraleiter-Bauelement
DE10212126A1 (de) Supraleitender Magnesiumdiborid-Dünnfilm und Verfahren und Vorrichtung zu seiner Herstellung
DE19940773A1 (de) Hochtemperatur-Supraleiter-Josephson-Übergang-Element und Herstellungsverfahren für dieses
DE3822905C2 (fr)
DE3822904C2 (fr)
DE2055606A1 (de) Dünnschicht Einkristall Bauelement mit Tunneleffekt
DE3834964A1 (de) Verfahren zur herstellung mindestens einer schicht aus einem metalloxidischen supraleitermaterial mit hoher sprungtemperatur
DE4120258A1 (de) Verfahren zur herstellung einer schicht aus einem hochtemperatursupraleiter-material auf einem silizium-substrat
DE19932444C1 (de) Verfahren zur Herstellung einer texturierten Schicht aus oxidischem Material auf einem Substrat und Verwendung des Verfahrens
DE69333799T2 (de) Bauelement mit Gitteranpassung und Verfahren zu seiner Herstellung
EP0330899B1 (fr) Procédé de préparation d'une couche en oxyde métallique supraconducteur à haute température critique et dispositif pour la mise en oeuvre de ce procédé
DE4104592A1 (de) Verfahren zur herstellung einer hochtemperatursupraleiter-schicht auf einem silizium-substrat
DE10248962B4 (de) Verfahren zur Herstellung einer Hochtemperatur-Supraleiterschicht
DE4210613C2 (de) Einrichtung zur Beschichtung eines Substrates mit einem metalloxidischen Hoch-T¶c¶-Supraleitermaterial
EP0405677B1 (fr) Dispositif électronique supraconducteur à couches minces et procédé pour sa fabrication
DE3815185C2 (fr)
DE3924022C2 (de) Verfahren zur Herstellung eines Josephson-Tunnelelementes mit metalloxidischem Supraleitermaterial
DE3834963A1 (de) Verfahren zur epitaktischen herstellung einer schicht aus einem metalloxidischen supraleitermaterial mit hoher sprungtemperatur
DE4141228A1 (de) Korngrenzen-josephsonelement und verfahren zu dessen herstellung
DE3815183C2 (fr)
DE10128660A1 (de) Verfahren zum Beschichten eines Substrats mit einer texturierten Schicht aus Indiumzinnoxid
DE4204370A1 (de) Verfahren zur herstellung von strukturierten leiterbahnen
WO2003054977A2 (fr) Procede de realisation de couches epaisses supraconductrices texturees, et structures supraconductrices texturees de façon biaxiale ainsi obtenues

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19901220

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB IT NL

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19940201