Abstract: This invention provides a thin superconducting oxide film, which can realize a high critical current, and a superconducting member having a high level of electric power resistance. The superconducting member comprises a sapphire R face substrate, a buffer layer formed of grain lumps of an oxide provided on the sapphire R face substrate, and a superconducting layer provided on the buffer layer. The nearest neighbor distance between oxygen atoms in the oxide and the grain diameter of grain lumps of the oxide have been specified. The superconducting member can be used as a member for superconducting filters.

Abstract: A signal switching device is disclosed that is capable of transmitting signals with less signal loss while securing a good isolation characteristic. The signal switching device includes a first section formed from a superconducting material connected to a first transmission path. The first section has a smaller cross section at the input end than at the output end or, the signal switching device may include a first section formed from a superconducting material connected to a first transmission path in series, and a second section formed from a superconducting material connected to a second transmission path in parallel. The cross section of the second section is smaller than that of the second transmission path. The length of the second transmission path is determined in such a way that an input impedance of the second transmission path is sufficiently large when the second section is in a superconducting state.

Abstract: A superconducting signal transmission apparatus provided with a vacuum container 11, a superconducting electronic device 12 provided in the vacuum container 11, an input side transmission line 13 and output side transmission line 14 for connection to the superconducting electronic device 12 through the vacuum container 11, and a cooling mechanism (15, 16, 17) for cooling the superconducting electronic device 12 and further having a heat cutoff signal transmission unit 20 inserted at least at part of the input side and output side transmission lines 13 and 14. The heat cutoff signal transmission unit 20 is comprised of a substrate 31 and a flat circuit body 30 provided with a signal transmission line 32 and ground layer (33, 33-1, 33-2). The substrate 31 is comprised of a dielectric material having a small heat conductivity. The conductor portions forming the signal transmission line 32 and the ground layer are formed with thin thicknesses enabling suppression of the inflow of heat from the outside.

Abstract: A superconductor on-chip microstrip line (2, 4) to off-chip microstrip line (7) transition of low characteristic impedance (15, 20, 22) is realized that obtains a bandwidth of 200 GHz for MCM application while employing solder bump (15, 17) technology to connect the chips (3, 5) to the off-chip microstrip and substrate (6). Circular openings (20, 22) through the respective ground plane layers (10 & 16) of the off-chip and on-chip microstrips are provided in positions respectively underlying and overlying the solder bump (15) for the signal. The openings may be sized to provide a desired ratio of inductance to capacitance, the larger the size, the greater the ratio value. This technique may be used to match characteristic impedance to give broad bandwidth low impedance interconnections needed for direct SFQ chip-to-chip communication on a passive MCM.

Abstract: The invention relates to a high-temperature superconductor component with a particular cross-sectional area, which has a current-carrying section, the current-carrying section being in contact with a safety conductor in such a way that the critical current flowing on transition of the superconductor to normal conduction can be taken up without damage by the safety conductor in at least 1 second and rerouted, as well as a process for its production.

Abstract: An HTS microwave circuit has two layers formed with metallic film on a substrate. One layer has a first circuit and another layer has a second circuit, the two circuits being coupled to one another. The second circuit has elements that are incompatible with HTS material such as MEMS technology and flip-chip technology. A microwave switch has a first layer that can carry an RF signal and a second layer that has switch elements that are controlled by a DC. signal. The RF signal and DC signal are isolated from one another. The switch elements include various technologies including a narrow HTS strip. A single layer HTS microwave switch can also be utilized where the switch element is a narrow HTS line. A method of combing HTS technology with incompatible technologies into one device is provided.

Abstract: A lanthanum aluminate (LaAlO3) substrate on which thin films of layered perovskite copper oxide superconductors are formed. Lanthanum aluminate, with a pseudo-cubic perovskite crystal structure, has a crystal structure and lattice constant that closely match the crystal structures and lattice constants of the layered perovskite superconductors. Therefore, it promotes epitaxial film growth of the superconductors, with the crystals being oriented in the proper direction for good superconductive electrical properties, such as a high critical current density. In addition, LaAlO3 has good high frequency properties, such as a low loss tangent and low dielectric constant at superconductive temperatures. Finally, lanthanum aluminate does not significantly interact with the superconductors. Lanthanum aluminate can also be used to form thin insulating films between the superconductor layers, which allows for the fabrication of a wide variety of superconductor circuit elements.

Abstract: Provided are an oxide superconducting wire which maintains a high critical current density and has a small current drift with small ac loss when the same carries an alternating current and a method of preparing the same, and a cable conductor which is formed by assembling such oxide superconducting wires. The oxide superconducting wire is a flat-molded stranded wire which is formed by twisting a plurality of metal-coated strands consisting of an oxide superconductor, and is characterized in that the flat-molded stranded wire has a rectangular sectional shape, and a section of each strand forming the flat-molded stranded wire has an aspect ratio (W1/T1) of at least 2. The method of preparing this oxide superconducting wire comprises the steps of preparing a stranded wire by twisting a plurality of strands, each of which is formed by metal-coating an oxide superconductor or raw material powder therefor, flat-molding the prepared stranded wire, and repeating rolling and a heat treatment of at least 800° C.

Abstract: A lanthanum aluminate (LaAlO.sub.3) substrate on which thin films of layered perovskite copper oxide superconductors are formed. Lanthanum aluminate, with a pseudo-cubic perovskite crystal structure, has a crystal structure and lattice constant that closely match the crystal structures and lattice constants of the layered perovskite superconductors. Therefore, it promotes epitaxial film growth of the superconductors, with the crystals being oriented in the proper direction for good superconductive electrical properties, such as a high critical current density. In addition, LaAlO.sub.3 has good high frequency properties, such as a low loss tangent and low dielectric constant at superconductive temperatures. Finally, lanthanum aluminate does not significantly interact with the superconductors. Lanthanum aluminate can also used to form thin insulating films between the superconductor layers, which allows for the fabrication of a wide variety of superconductor circuit elements.

Abstract: A method for the fabrication of active semiconductor and high-temperature superconducting device of the same substrate to form a monolithically integrated semiconductor-superconductor (MISS) structure is disclosed. A common insulating substrate, preferably sapphire or yttria-stabilized zirconia, is used for deposition of semiconductor and high-temperature superconductor substructures. Both substructures are capable of operation at a common temperature of at least 77 K. The separate semiconductor and superconductive regions may be electrically interconnected by normal metals, refractory metal silicides, or superconductors. Circuits and devices formed in the resulting MISS structures display operating characteristics which are equivalent to those of circuits and devices prepared on separate substrates.

Abstract: Microstrip/stripline transmission lines have a plurality of strips on a substrate where strips are separated by a gap. This arrangement results in a reduced maximum current density compared to previous transmission lines with the same power handling capability. The strips can have the same width or different widths. The gaps can have the same width or different widths. The transmission lines can be used in filters and resonators and can be made of high temperature superconductive materials.

Abstract: A superconducting ceramic film is deposited on a substrate sputtering. In virtue of the low thermal conductivity of ceramic, a laser beam is radiated to the ceramic film in order to remove the irradiated portion by sublimation and produce a pattern on the ceramic film.

Abstract: A superconducting oxide ceramic pattern is described. The pattern is comprised of a high Tc superconducting region and a low Tc superconducting region which exhibits a resistivity at the liquid nitrogen temperature while the high Tc region is superconducitive at that temperature. The low Tc region is doped with impurity such as Si and then subjected to thermal treatment to oxidizing the impurity.

Abstract: This invention permits superconducting ceramics, as well as other ceramic materials, to be spray deposited onto indefinitely large sheets of metallic substrate from a carboxylic acid salt solution. Elemental metal precursors of the superconductor are introduced into the solution as carboxylic acid salts. The deposit formed on the malleable metallic substrate is then thermomechanically calcined to form c-axis textured metal-superconductor composite sheet structures. These composite sheet structures can be formed by pressing together two ceramic-substrate structures, ceramic face-to-face, to form a metal-ceramic-metal sheet structure, or by overlaying a metal sheet over the deposited structure. Once the structure has been thermomechanically calcined, the c-axis of the superconductor is oriented parallel to the vector defining the plane of the metal sheet, i.e., perpendicular to the surface of the plane.

Abstract: Patterned superconducting wiring lines each having a portion of a thin film of an oxide superconductor deposited on a flat substrate, the portion having a predetermined crystal orientation (a-axis or c-axis orientation) with respect to a flat surface of the substrate, remaining portions of the thin film of the oxide superconductor having a different crystal orientation (c-axis or a-axis orientation) from the portion and/or having an insulation zones. Both of the portion and the remaining portions have a substantially identical thickness so that the thin film has a substantially flat planar surface.

Abstract: A superconducting multilayer ceramic substrate is disclosed, prepared by firing a laminate of at least two polymer bonded cast sheets of a ceramic dielectric oxide powder, at least one sheet of which has a metallization pattern provided thereon, to thereby form a superconducting oxide reaction layer at the interface between the sintered ceramic material and the embedded metallic conductor lines of the metallization pattern.

Abstract: A superconductive electrical device is operable simultaneously at relatively higher temperatures, i.e., 60-90K, and at relatively lower temperatures, i.e., less than 12K. The device comprises a non-superconductive substrate with two regions, a first relatively high temperature region and a second relatively low temperature region. A high temperature superconductor is on the first region and a portion of the second region. A dielectric layer is on the high temperature superconductor. A low temperature superconductor is on the second region of the substrate and on a portion of the dielectric layer. Integrated circuit chips can be secured to both superconductors, thereby yielding a superconductive multi-chip module operable at two different temperatures, such as in a cryo-cooler with two temperature stages.

Abstract: A superconductor device which includes a first wiring part and a second wiring part which together form a superconductive wiring. The first wiring part is arranged onto a substrate and is made of a superconductor material. The second wiring part is made of a non-oxide semiconductor material. The second wiring part is adjacent to the first wiring part and jointly forms a superconductive wiring with the first wiring part by becoming at least partly superconductive due to proximity effect with the first wiring part. The second wiring part has a smaller penetration length of magnetic field than that for the first wiring part. This structure enhances the propagation velocity of a signal within the superconductive wiring.

Abstract: Process for manufacturing a high interconnection density, fine-line, superconductive printed leadframes using thick-film screen-printing techniques, or other printing techniques. Generally, a superconductive leadframe pattern is printed on a backing substrate. Once the pattern is cured, the backing substrate, or portions thereof can be removed. The backing substrate can be a "fish paper" substrate treated with a release agent, or other substrate material which can be dissolved away, etched away, or otherwise removed. Portions of the backing substrate can be used to provide mechanical integrity for the leadframe. The leadframe fingers can be printed using a superconductive paste or a superconductive precursor paste which is subsequently treated to exhibit superconductivity.

Abstract: A superconducting circuit having patterned superconducting wiring lines. Each wiring line consists of at least one portion (2') of the thin film (2) of an oxide superconductor deposited on a substrate (1). The portion (2') has a predetermined crystal orientation and the remaining portions (2") have a different crystal orientation or changed to non-superconductor. The superconducting circuit has a planar surface.In variations, two different wiring lines (21, 22) each having a different crystal orientation are produced at different portions of a thin film of oxide superconductor, so that superconducting current flow separately through two different portions in a common thin film.

Abstract: Excellent films of a high Tc superconductor are easily produced on metal coated substrates at a temperature below 700.degree. C. These metal buffer films are made of Pt, Au, Ag, Pd, Ni or Ti. The film superconductivity is significantly improved by the metal buffer layer. Since it is easy to form this metal coating on a substrate, the invention can increase the potential number of usable substrates such as fibers, amorphous solids or semiconductors.

Abstract: Patterned superconducting wiring lines each consisting of a portion of a thin film of an oxide superconductor deposited on a flat substrate, the portion having a predetermined crystal orientation (a-axis or c-axis orientation) with respect to a flat surface of the substrate, remaining portions of the thin film of the oxide superconductor having a different crystal orientation (c-axis or a-axis orientation) from the portion and/or consisting of an insulation zones. Both of the portion and the remaining portions have a substantially identical thickness so that the thin film has a substantially flat planar surface.

Abstract: A superconducting active lumped component for microwave device application including a dielectric substrate, a first superconducting portion of an oxide superconductor provided on said dielectric substrate, an insulator layer formed on the first superconducting portion and a second conductive portion arranged on the insulator layer in which the conductivity of the first superconducting electrode and the dielectric property of the insulator layer can be changed by a dc bias voltage applied between the first and the second conductive portion so that capacitance and/or inductance and/or microwave resistance can be changed.

Abstract: A new type of superconducting device is disclosed. The device embodies a superconducting ceramic film as an active part. A control electrode is provided on the superconducting film in which a passing current is controlled by applying a voltage on an intermediate portion of the film.

Abstract: Various techniques for forming superconductive lines are described whereby superconductive lines can be formed by stamping, etching, polishing, or by rendering selected areas of a superconductive film (layer) non-superconductive. The superconductive material can be "perfected" (or optimized) after it is formed into lines (traces). In one embodiment, trenches are etched in a substrate, the trenches are filled with superconductive material, and any excess superconductive material overfilling the trenches is removed, such as by polishing. In another embodiment, superconductive lines are formed by rendering selected areas of a superconductive layer (i.e., areas other than the desired superconductive lines) non-superconductive by "damaging" the superconductive material by laser beam heating, or by ion implantation. Superconductive lines formed according to the invention can be used to protect semiconductor devices (e.g.

Abstract: A lanthanum aluminate (LaAlO.sub.3) substrate on which thin films of layered perovskite copper oxide superconductors are formed. Lanthanum aluminate, with a pseudo-cubic perovskite crystal structure, has a crystal structure and lattice constant that closely match the crystal structures and lattice constants of the layered perovskite superconductors. Therefore, it promotes epitaxial film growth of the superconductors, with the crystals being oriented in the proper direction for good superconductive electrical properties, such as a high critical current density. In addition, LaAlO.sub.3 has good high frequency properties, such as a low loss tangent and low dielectric constant at superconductive temperatures. Finally, lanthanum aluminate does not significantly interact with the superconductors. Lanthanum aluminate can also be used to form thin insulating films between the superconductor layers, which allows for the fabrication of a wide variety of superconductor circuit elements.

Abstract: A superconducting device comprising a substrate having a principal surface, a superconducting source region and a superconducting drain region formed of an oxide superconductor on the principal surface of the substrate separated from each other, a superconducting channel formed of the oxide superconductor between the superconducting source region and the superconducting drain region. The superconducting channel electrically connects the superconducting source region to a superconducting drain region, so that a superconducting current can flow through the superconducting channel between the superconducting source region and the superconducting drain region. The superconducting device comprises a gate electrode through a gate insulator on the superconducting channel for controlling the superconducting current flowing through the superconducting channel, and non-superconducting oxide layers having a similar crystal structure to that of the oxide superconductor.

Abstract: A superconducting multilayer interconnection comprises a substrate having a principal surface, a first superconducting current path of a c-axis orientated oxide superconductor thin film formed on the principal surface of the substrate, an insulating layer on the first superconducting current path, and a second superconducting current path of a c-axis orientated oxide superconductor thin film formed on the insulating layer so that the first and second superconducting current paths are insulated by the insulating layer. The superconducting multilayer interconnection further comprises a superconducting interconnect current path of an a-axis orientated oxide superconductor thin film, through which the first and second superconducting current paths are electrically connected each other.

Abstract: A superconducting thin film formed on a substrate, comprising an a-axis orientated oxide superconductor layer, a c-axis orientated oxide superconductor layer and an oxide semiconductor layer inserted between the a-axis orientated oxide superconductor layer and the c-axis orientated oxide superconductor layer, in contact with them in which superconducting current can flow between the a-axis orientated oxide superconductor layer and the c-axis orientated oxide superconductor layer through the oxide semiconductor layer by a long-range proximity effect.

Abstract: Josephson contacts are fabricated in ceramic compounds from classes of high temperature superconductors. The succession of layers in the single-crystal determines the properties of the Josephson contacts. The supercurrent flows in the direction of the crystallographic c-axis. In a category of substances of high temperature superconductors the Josephson contacts are located in the space between each of two copper oxide planes. In a different class of high temperature superconductors the Josephson contacts are located between each of two single copper oxide planes. The electrical properties such as critical supercurrent density, capacitance and shunt resistance or the Josephson contacts are adjusted by controlled addition or controlled withdrawal of oxygen. Using stacks of such intrinsic Josephson contacts within a single-crystal, current-controllable high frequency generators, Josephson voltage normals and SQUIDS can be realized.

Abstract: The ferroelectric limiter utilizes the bias voltage dependent dielectric constant property of a ferroelectric material. A main transmission line having a length of two or more half wavelengths at the operating frequency is used. A branch line is connected at one half wavelength away from one end of the transmission line. The branch line presents a very high impedance on the main transmission line at a low level of signal. The branch line contains a ferroelectric material. As the signal level increases, the dielectric constant of the ferroelectric material in the branch line changes. This reduces the impedance presented by the branch line on the main transmission line reducing the impedance of the main transmission line and the resulting output of the limiter. As the signal level increases, the impedance presented by the branch line on the main transmission line becomes increasingly smaller, further reducing the output of the of the limiter. Two designs of the limiter are presented.

Abstract: Superconducting device include a type having a structure of a superconductor--a normal-conductor (or a semiconductor)--a superconductor, and a type having a superconducting weak-link portion between superconductors.The superconductors constituting the superconducting device are made of an oxide of either of perovskite type and K.sub.2 NiF.sub.4 type crystalline structures, containing at least one element selected from the group consisting of Ba, Sr, Ca, Mg, and Ra; at least one element selected from the group consisting of La, Y, Ce, Sc, Sm, Eu, Er, Gd, Ho, Yb, Nd, Pr, Lu, and Tb; Cu; and O. In addition, the c-axis of the crystal of the superconductor is substantially perpendicular to the direction of current flowing through this superconductor.

Abstract: An article of manufacture having an epitaxial (111) magnesium oxide (MgO) layer, suitable for use as a buffer layer, on a (111) surface of a tetrahedral semiconductor substrate, and method for its manufacture is described. The article may further include an epitaxial oxide overlayer on the (111) MgO layer. The overlayer may be a conducting, superconducting, and/or ferroelectric oxide layer. The method of producing the epitaxial (111) magnesium oxide (MgO) layer on the (111) surface of a tetrahedral semiconductor substrate proceeds at low temperature. The method may further include steps for forming the epitaxial oxide layer on the (111) MgO layer. The methods include the steps of preparing the (111) surface of a tetrahedral semiconductor substrate for deposition and the low temperature depositing of an MgO layer on the prepared surface. Further steps may include the depositing of the oxide layer over the MgO layer.

Abstract: A superconducting device includes a superconducting channel constituted of an oxide superconductor thin film formed on a substrate, a superconductor source electrode and a superconductor drain electrode formed at opposite ends of the superconducting channel, so that a superconducting current can flow through the superconducting channel between the source electrode and the drain electrode. A gain electrode is located through an insulating layer on the superconducting channel so as to control the superconducting current flowing through the superconducting channel. The oxide superconductor thin film of the superconducting channel is formed of a c-axis oriented oxide superconductor crystal, and the oxide superconductor thin film of the superconductor source electrode and the superconductor drain electrode are formed of an a-axis oriented oxide superconductor crystal. The superconducting channel is continuous with the superconductor source electrode and the superconductor drain electrode.

Abstract: Electronic circuit node structures which minimize parasitic capacitance in linear path and angular circuit topographies for high frequency circuits are described. The electronic circuit comprises at least two signal conductor elements and an active or passive circuit element on a substrate. The conductor elements are arranged to define a gap between their ends. The circuit element bridges the gap. In one embodiment, the longitudinal axes of the conductor elements are laterally offset and generally parallel. The conductors are arranged to form the gap between adjacent edges on the ends of the conductors. The circuit element is arranged to bridge the gap. The other conductor edges near the gap are arranged at angles which increase the distance between them. In another embodiment, the conductor elements form an angle with the gap at the apex. The circuit element bridges the gap between the conductor edges nearest the apex.

Abstract: A superconducting circuit board is provided comprising a sintered alumina board containing more than 99% by weight of alumina and an interconnection pattern of an superconducting ceramics formed on the alumina board. Adhesion of the interconnection pattern to the alumina board is improved by an addition of Ti or Si coupling agent to a paste for forming the interconnection pattern. The use of copper powder in place of copper oxide powder as an ingredient forming a superconducting ceramics in the paste is advantageous for printing and obtaining a uniform superconducting ceramic pattern.

Abstract: An improved electric device utilizing a superconducting material. In order to avoid undesirable oxidation during firing of a ceramic to be superconducting material formed on the substrate, the superconducting material is provided only on the position in which the superconducting material does not contact the operational region of said semiconductor substrate.

Abstract: An electric circuit is provided on a semiconductor substrate with a supercoducting film. The surfaces being in contact with the superconducting film are made of heat-resistant non-oxide insulating materials so that the performance of the superconducting film is not degraded.

Abstract: A detector useful for detecting infrared (IR) radiation is described which is formed of an epitaxial film of superconductive material having a high transition temperature Tc. Specifically, an oxide of yttrium barium and copper is preferred for the high Tc material. The sensor is formed on a single crystalline silicon body suspended by a silicon nitride membrane over a gap formed in a silicon base body and thermally isolated thereby.

Abstract: An article of manufacture including a substrate, a patterned interlayer of a material selected from the group consisting of magnesium oxide, barium-titanium oxide or barium-zirconium oxide, the patterned interlayer material overcoated with a secondary interlayer material of yttria-stabilized zirconia or magnesium-aluminum oxide, upon the surface of the substrate whereby an intermediate article with an exposed surface of both the overcoated patterned interlayer and the substrate is formed, a coating of a buffer layer selected from the group consisting of cerium oxide, yttrium oxide, curium oxide, dysprosium oxide, erbium oxide, europium oxide, iron oxide, gadolinium oxide, holmium oxide, indium oxide, lanthanum oxide, manganese oxide, lutetium oxide, neodymium oxide, praseodymium oxide, plutonium oxide, samarium oxide, terbium oxide, thallium oxide, thulium oxide, yttrium oxide and ytterbium oxide over the entire exposed surface of the intermediate article, and, a ceramic superco nFIELD OF THE INVENTIONThe pre

Abstract: A method for fabricating an active device comprises the steps of injecting particles into a single crystal substrate of a semiconductor material at a predetermined depth from the surface, annealing the substrate that contains the particles to form an insulator layer within the substrate, generally in correspondence to the predetermined depth, the step of annealing including a step of forming a single crystal semiconductor layer of a semiconductor material identical in composition with the substrate, on the insulator layer that is formed by the annealing, starting a deposition of a layer of an oxide superconductor on the semiconductor layer, growing the oxide superconductor layer while maintaining an epitaxial relationship with respect to the substrate; and converting the semiconductor layer to an oxide layer simultaneously to the growth of the oxide superconductor layer.

Abstract: A superconducting device comprises a substrate having an electric connecting section and a copper oxide superconducting material thereon, and an electric interconnecting means for the electric connecting section and the superconducting material formed from a first member selected from the group of copper, gold, platinum and materials including copper, gold, and platinum as a main component and tightly attached to the superconducting material, and/or a second member selected from the group of a heat resistant metal material and its compound with the first member and the substrate material and tightly attached to the first member and the substrate.

Abstract: A superconducting pattern formed from a superconducting ceramic film is illustrated. The pattern is made in the form of a coil which is embedded in an insulating ceramic film. The insulating film is made of a ceramic material whose thermal expansion coefficient is approximately equal to that of the coil.

Abstract: A method for producing an oxide superconducting connecting line includes initially coating a line with at least one layer of a crystalline or amorphous metal alloy forming a superconductive oxide. The line is subsequently heated to a temperature below the melting temperature of the oxide. A gas containing oxygen is simultaneously brought into contact with the accessible surface forming an oxide film which is superconductive upon cooling. When the oxide film is damaged at a certain location, the still-undamaged layer is exposed to the oxygen-containing gas and the line is heated at the damaged location. A superconducting film is again formed. A combination superconducting connecting line and an apparatus for producing the superconducting connecting line is also disclosed.

Abstract: A superconducting device comprises a substrate having an electric connecting section and a copper oxide superconducting material thereon, and an electric interconnecting means for the electric connecting section and the superconducting material formed from a first member selected from the group of copper, gold, platinum and materials including copper, gold, and platinum as a main component and tightly attached to the superconducting material, and/or a second member selected from the group of a heat resistant metal material and its compound with the first member and the substrate material and tightly attached to the first member and the substrate.

Abstract: Disclosed here is a shaped article superconductor comprising platelets of superconducting oxide crystals which are normally anisotropic but in which said anisotropy is reduced by joining together the oxides superconductor crystallites with a normally conductive metal layer interposed therebetween. The separation distances of the platelets are, on the average, less than the coherence length of the normally conductive metal under conditions which render the oxide crystals superconductive.

Abstract: A method for manufacturing a superconductive multilayer circuit has a first thin film forming step for forming a thin film, which is composed of superconductive material or a similar material thereto, on a substrate, a first circuit layer forming step for forming a superconductive circuit by discharging a specific component from a predetermined part of the thin film or implanting the component in the thin film, a second thin film forming step for forming a thin film, which is composed of a superconducting material or the simulant thereto, on the first circuit layer, and a second circuit layer forming step for forming a superconductive circuit by removing a specific component from a predetermined part of the thin film or implanting the component in the thin film.

Abstract: Bi-based superconducting ceramic films having high Tc's and high critical current densities are formed. The superconducting film is formed on a non-superconducting saubstrate of Bi.sub.2 Sr.sub.1-x Ca.sub.x O.sub.y. Due to crystalline similarity between the superconducting film and the underlying ceramic substrate, the crystalline structure of the film is improved. There are few impurities which contaminate the superconducting film since the constituent elements of the substrate are also the consitutents of the superconducting film.

Abstract: A superconducting composite comprising a compound oxide type superconductor and an outer metal pipe on which said superconductor is supported, characterized in that (i) said outer metal pipe is made of at least one of metals selected from a group comprising gold, silver and platinum metals and their alloys or (ii) an intermediate layer made of these precious metals is interposed between the compound oxide and the metal pipe.The composite may be in a form of a solid pipe or a hollow pipe having a superconducting thin layer deposited on an inner surface of the metal pipe.

Abstract: Excellent films of a high Tc superconductor are easily produced on metal coated substrates at a temperature below 700.degree. C. These metal buffer films are made of Pt, Au, Ag, Pd, Ni or Ti. The film superconductivity is significantly improved by the metal buffer layer. Since it is easy to form this metal coating on a substrate, the invention can increase the potential number of usable substrates such as fibers, amorphous solids or semiconductors.