Abstract: A method for fabricating a superconducting device with a substrate, a first oxide superconductor thin film, a barrier layer, a diffusion layer, and a second oxide superconductor thin film. The first oxide superconductor thin film with a very thin thickness is formed on the principal surface of the substrate. The barrier layer and the diffusion source layer are formed on a portion of the first oxide superconductor thin film. The second oxide superconductor thin film is grown on an exposed surface of the first oxide superconductor thin film until the barrier and diffusion source layers are embedded in the second oxide superconductor thin film, so that a material of the diffusion source layer is diffused into the second oxide superconductor thin film.

Abstract: A Josephson junction device comprises a single crystalline substrate including a principal surface, an oxide layer formed on the principal surface of the substrate having a step on its surface and an oxide superconductor thin film formed on the surface of the oxide layer. The oxide superconductor thin film includes a first and a second portions respectively positioned above and below the step of the oxide layer, which are constituted of single crystals of the oxide superconductor, and a step-edge junction made up of a grain boundary on the step of the oxide layer, which constitutes a weak link of the Josephson junction.

Abstract: A superconducting element is disclosed which includes a substrate and a superconducting layer provided on the substrate and formed of an oxide having the following chemical formula:RBa.sub.2 (Cu.sub.1-x M.sub.x).sub.3 O.sub.7wherein R represents at least one element selected from the group consisting of Y, La, Nd, Pm, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu, M represents at least one element selected from the group consisting of Al, Ti, V, Cr, Mn, Fe, Co, Ni, Zn and Ga, and x represents a number of less than 1 but greater than 0.

Abstract: A conductor suitable for use in oxide-based electronic devices and circuits is disclosed. Metallic oxides having the general composition AMO.sub.3, where A is a rare or alkaline earth or an alloy of rare or alkaline earth elements, and M is a transition metal, exhibit metallic behavior and are compatible with high temperature ceramic processing. Other useful metallic oxides have compositions (A.sub.1-x A'.sub.x)A".sub.2 (M.sub.1-y M'.sub.y).sub.3 O.sub.7-.delta. or (A.sub.1-x A'.sub.x).sub.m (M.sub.1-y M'.sub.y).sub.n O.sub.2m+n, where 0.ltoreq.x, y.ltoreq.1 and 0.5.ltoreq.m, n.ltoreq.3, A and A' are rare or alkaline earths, or alloys of rare or alkaline earths, A' and A" are alkaline earth elements, alloys of alkaline earth elements, rare earth elements, alloys of rare earth elements, or alloys of alkaline earth and rare earth elements, and M and M' are transition metal elements or alloys of transition metal elements.

Abstract: A thin film which is substantially free of measurable surface defects due to second-phase inclusions is disclosed. The film is composed of multilayered strata of a first metal oxide interspersed with single molecular layers of a second metal oxide, where the second metal oxide is effective to absorb second-phase defects which form in the first oxide layers.

Abstract: A superconducting device or a super-FET has a pair of superconducting electrode regions (20b, 20c) consisting of a thin film (20) oxide superconductor being deposited on a substrate (5) and a weak/ink region (20a), the superconducting electrode regions (20b, 20c) being positioned at opposite sides of the weak link region (20a), these superconducting electrode regions (20b, 20c) and the weak link region (20a) being formed on a common plane surface of the substrate (5). The weak link region (20a) is produced by local diffusion of constituent element(s) of the substrate (5) and/or a gate electrode insulating layer (16) into the thin film (20) of the oxide superconductor in such a manner that a substantial wall thickness of the thin film (20) of the oxide superconductor is reduced at the weak link region (20a) so as to leave a weak link or superconducting channel (10) in the thin film (20) of oxide superconductor over a non-superconducting region (50) which is produced by the diffusion.

Abstract: The present invention discloses a process for forming an a-axis superconducting junction by adjusting the deposition temperature of an oxide normal conductor layer/and oxide superconductor layer/an oxide insulating layer/an oxide normal conductor layer/and an oxide superconductor layer, which are sequentially multilayered on an oxide single crystalline substrate. According to the present invention, the oxide superconductor layer and the oxide insulating layer have an a-axis oriented perpendicularly, and the oxide normal conductor layer have a b-axis oriented perpendicularly, so that a superconductor Josephson junction may be obtained.

Abstract: The present invention provides a superconducting device having a weak link junction with an angle at the grain boundary between the two superconductor crystals being variable. The angle at the junction is substantially equivalent to a vicinal angle for the substrate. Accordingly, the magnitude of the angle at the junction can be varied by varying the vicinal angle of the substrate. This result can be realized by using buffer layers of different compositions underlying the superconducting materials on either side of the weak link junction. Weak link junctions and reproducible properties are essential for a variety of electronic and magnetic sensing devices.

Abstract: A process for depositing successively a plurality of thin films on a bottom superconductor layer made of oxide superconductor deposited on a substrate in a single chamber under a condition, the bottom superconductor layer is heated in ultra-high vacuum at a temperature which is lower than the oxygen-trap temperature (T.sub.trap) at which oxygen enter into the oxide superconductor but higher than a temperature which is lower by 100.degree. C. than the oxygen-trap temperature (T.sub.trap -100.degree. C.) and then the first thin film is deposited thereon.

Abstract: A HTSC Josephson device wherein the barrier layer is a cubic, conductive material.

Abstract: The present invention relates to a method for foxing a step on a deposition surface of a substrate for depositing a thin film on it. According to the method, the step is formed by etching a portion of the deposition surface of the substrate by emitting a laser beam to the portion.

Abstract: A Josephson junction device is disclosed that includes a single crystalline substrate having a NaCl type crystal structure. The device includes a principal surface having two horizontal planes and a slope inclined at an angle of 5.degree. to 30.degree. between the two horizontal planes. An oxide superconductor thin film is formed on the principal surface of the substrate, which includes first and a second superconducting portions of a first single crystalline oxide superconductor and a second single crystalline oxide superconductor respectively positioned on the two horizontal planes of the substrate. A junction portion of a single crystalline oxide superconductor has a different crystal orientation from the first and the second superconducting portions, and is positioned on the slope of the substrate. Two grain boundaries between each of the first and the second superconducting portions and the junction portion constitute one weak link of the Josephson junction.

Abstract: A method is provided for producing superconducting Josephson devices using a chemical etching solution which comprises forming a mask on a predetermined portion of a MgO substrate, and immersing the MgO substrate having the mask in an aqueous acid solution in which the volume ratio of phosphoric acid to sulfuric acid is approximately 10:1 or more, so as to form a step at the boundary between the masked region and the unmasked region.

Abstract: A method of forming a high-Tc microbridge superconductor device is disclosed, which comprises the steps of forming an inclined step on the surface of a substrate, the inclined step having an angle of inclination of from about 20 to about 80 degrees; depositing a layer of c-axis oriented superconductor material overlying the substrate such that there is a break in the layer of superconductor material at the inclined step; and depositing a layer of normal material overlying the layer of c-axis oriented superconductor material.

Abstract: A superconductor junction material is disclosed which comprises a substrate of a single crystal, and at least flux flow element, and optionally at least one Josephson junction element, provided on the surface, each of the flux flow and Josephson junction elements being formed of a superconducting oxide layer having a weak link. The flux flow and Josephson junction elements are prepared by vacuum deposition at different oxygen partial pressures.

Abstract: A thin film of oxide superconductor consisting of more than two portions (1, 11, 12) each possessing a predetermined crystal orientation and deposited on a common surface of a substrate (2). At least one selected portion (10) of thin film of oxide superconductor is deposited on a thin under-layer (4, 100) which facilitates crystal growth of selected portions and which is deposited previously on the substrate. The selected portions (10) may consist of a-axis oriented thin film portions while non-selected portions (11, 12) may consists of c-axis oriented thin film portions. The thin under-layer can be a buffer layer (4) or a very thin film (100) of oxide superconductor.

Abstract: This invention relates to a process of forming multilayered thallium-containing superconducting composites, wherein a first thallium-containing superconducting layer, an intermediate thallium-containing oxide layer and a second thallium-containing superconducting layer are successively deposited on a substrate by a vapor phase process by controlling the heating temperature, pressure of oxidizing gas and thallium vapor pressure during post-deposition annealing of the superconducting films.

Abstract: For manufacturing a superconducting device having a tunnel junction formed of an extremely thin insulator layer sandwiched between a pair of oxide superconductor thin films, a first superconducting layer of oxide superconductor thin film is formed on a substrate, and a MgO thin film is deposited on the first superconducting layer at a substrate temperature of not higher than 200.degree. C. The MgO thin film is heat-treated so that crystallinity of the deposited MgO thin film is improved, and thereafter, a second superconducting layer of oxide superconductor thin film is formed on the MgO thin film.

Abstract: The present invention relates to a method or forming a step on a deposition surface of a substrate for depositing it thin film on it. The method comprises steps of etching a portion of the deposition surface of the substrate and conducting heat treatment of the substrate so as to recover crystallinity of the etched surface. The method can comprise steps of etching a portion of the deposition surface of the substrate and further etching the etched portion of the deposition surface of the substrate slightly so as to remove a degraded surface.

Abstract: A superconducting magnetoresistive element has superconducting portions having a high critical current density and weak-coupling portions having a low critical current density. The superconducting portions and weak-coupling portions are alternately arranged and connected in series. The superconducting magnetoresistive element is fabricated, for example, by forming semiconductor films at a plurality of sites on a substrate in a manner that the semiconductor films are spaced from each other, then forming a superconducting thin film all over the substrate and processing the superconducting thin film into a line pattern which passes over the plurality of semiconductor films, and heat-treating the substrate to diffuse a constituent element of the semiconductor films in the superconducting thin film. Portions of the superconducting thin film overlying the semiconductor films become the weak-coupling portions and the rest portions of the superconducting thin film become the superconducting portions.

Abstract: A process for producing a layered structure containing at least one thin film of oxide superconductor (1) such as Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x having a contaminated surface on a substrate (3). The contaminated surface of the thin film of oxide superconductor is heat-treated in an atmosphere containing oxygen of high purity of higher than 5N and a partial pressure of 25 Torr at a temperature of 350.degree. to 700.degree. C. On the thin film of oxide superconductor (1), another thin film (2) of oxide superconductor or non-superconductor is deposited.The resulting structure of layered thin films is used for fabricating superconducting transistor, Josephson junctions, superconducting circuits or the like.

Abstract: A manufacturing method of a superconducting pattern is described. A superconducting ceramic film is deposited on a non-conductive surface and partly spoiled in order to form a barrier film by which two superconducting regions is separated. The spoiling is performed by adding a spoiling element into the ceramic film by ion implantation.

Abstract: A superconducting device has a substrate and a superconducting film formed on the substrate. A surface of the substrate has a first surface portion of which a curvature is constant or changes continuously, a second surface portion of which a curvature is constant or changes continuously, and a third surface portion at which the first and second surface portions meet and at which the curvatures of the first and second surface portions become discontinuous. The superconducting film formed on the surface of said substrate has a grain boundary serving as a junction only in a portion corresponding to the third surface portion of the substrate.

Abstract: A superconductor device is provided including a base, a base electrode formed on the base which is made of a Bi-system oxide superconductive material containing an alkaline earth metal, a barrier layer formed on the base electrode which is made of Bi--Sr--Cu--O, a counter electrode formed on the barrier layer which is made of a Bi-system oxide superconductive material containing an alkaline earth metal, a contact electrode formed so as contact with the counter electrode, and a separation layer for separating said contact electrode from said base electrode.

Abstract: An anisotropic superconductor junction device consisting of a lower superconducting layer and an upper superconducting layer separated by a barrier layer, in which the upper and lower superconducting layers and the barrier layer each have a (103) crystal orientation in which the c axis is arranged in the same direction at an angle of 45 degrees relative to the plane of the junction.

Abstract: A superconducting device has a structure of superconductor--normal--conductor (semiconductor)--superconductor. The superconducting regions and the normal-conductor region can be made of the same elements but having different relative proportions of the elements. The device can be fabricated by introducing at least one element into an unmasked region of the superconductor to form a normal conductor region or into unmasked regions of the normal conductor to form superconductor regions.

Abstract: For manufacturing a superconducting thin film having at least one non-superconducting region at and near its surface portion, an oxide superconductor thin film is formed on a surface of the substrate. The oxide superconductor thin film is heated in high vacuum environment so that oxygen of the oxide superconductor crystals escapes from the surface of the oxide superconductor thin film and a surface portion of the oxide superconductor thin film having a substantial thickness changes into non-superconducting layer of a compound oxide which is composed of the same constituent elements as those of the oxide superconductor but includes the oxygen amount less than that of the oxide superconductor and a thin superconducting channel is formed under the non-superconducting layer.

Abstract: A method for producing multilayer structures comprised of materials with incompatible processing parameters is disclosed. A bonding layer of arbitrary dielectric constant is applied to each of two substructures. Each substructure is composed of a substrate and at least one epitaxial crystalline layer. Examples of particular bonding materials used are polyimide, fluorocarbon polymers, other organic materials, and glass. The bonding material may be applied like photoresist, or sputtered, or applied in any appropriate manner consistent with the processing constraints of the crystalline materials. Structures formable in this way include superconductor-amorphous dielectric-superconductor and ferroelectric-insulator-semiconductor trilayers, as well as microwave resonators and multichip modules.

Abstract: A method for forming a patterned oxide superconductor thin film on a substrate comprises steps of forming a metal or semi-metal layer on a portion of the substrate, on which the oxide superconductor thin film will be formed, forming a layer of a material including silicon on a portion of the substrate, on which an insulating layer will be formed, removing the metal or semi-metal layer and depositing an oxide superconductor thin film over the substrate.

Abstract: A Josephson junction device comprises a single crystalline substrate including a principal surface having a first and a second regions of which at least lattice distance of exposed lattices are slightly different from each other and an oxide superconductor thin film formed on the principal surface of the substrate. The oxide superconductor thin film includes a first and a second portions respectively positioned on the first and the second regions of the substrate, which are constituted of single crystals of the oxide superconductor, lattices of the one shifts at angle of 45.degree. to that of the other, and a grain boundary between said two portions, which constitutes a weak link of the Josephson junction.

Abstract: A method for depositing a thin film of a material on an oxide thin film having a perovskite type crystal structure formed on a substrate comprising steps of depositing a seed layer of a single crystal of the material having an extremely thin thickness at a relatively high substrate temperature on the oxide thin film having a perovskite type crystal structure and depositing a thin film of the material on the seed layer at a lower substrate temperature.

Abstract: A SQUID comprises a substrate, a washer of an oxide superconductor thin film formed on a principal surface of the substrate, a hole shaped a similar figure to the washer at the center of the washer, a slit formed between one side of the washer and the hole, and a Josephson junction which connects portions of the washer at the both sides of the slit across the slit. In the SQUID, the ratio of similarity of the washer to the hole ranges 100 to 2500.

Abstract: A weak link is patterned from a high-temperature superconducting film using standard lithographic techniques. Once the area in which the weak link is to be located is defined, the remainder of the film is covered with an oxygen-impermeable material. The oxygen is then removed in the weak link area by placing the sample in a vacuum furnace at a sufficient temperature to drive out the oxygen. Once the oxygen is removed, the weak link becomes non-superconducting. A high power solid state laser is placed in front of the weak link, and superconductivity is restored in the weak link area, in situ. The process is performed in a liquid nitrogen environment.

Abstract: c-axis oriented YBa.sub.2 Cu.sub.3 O.sub.7 layers are grown with intervening SrTiO.sub.3 layers bridged over steps at which there is a transformation to a-axis crystal-oriented growth. The multilayer superconductor has YBa.sub.2 Cu.sub.3 O.sub.7 layers which are not thicker than 500 nm while the intervening layers of SrTiO.sub.3 have thicknesses of 20 to 30 nm.

Abstract: A superconducting device includes a first thin film of oxide superconductor material formed on a substrate, a second thin film of insulator material stacked on the first thin film of oxide superconductor material, and a third thin film of oxide superconductor material formed on the second thin film of insulator material. The second thin film of insulator material is formed of an amorphous oxide including the same constituent elements as those of the oxide superconductor material of the first thin film. The second thin film of insulator material is formed by heat-treating the first thin film of oxide superconductor material in a gaseous atmosphere bringing a surface of the oxide superconductor material into an amorphous condition, after the first thin film of oxide superconductor material has been formed on the substrate.

Abstract: A Josephson junction device comprising a single crystalline substrate including a principal surface having two horizontal planes and a smooth slope between the two horizontal planes, and an oxide superconductor thin film formed on the principal surface of the substrate. The oxide superconductor thin film includes a first and a second superconducting portions of a single crystalline oxide superconductor respectively positioned on the two horizontal planes of the substrate, a junction portion of a single crystalline oxide superconductor having a different crystal orientation from the two superconducting portions positioned on the slope of the substrate and two grain boundaries between each of the two superconducting portions and the junction portion. The grain boundaries constitutes one weak link of the Josephson junction.

Abstract: A thin film device comprising a substrate and an oxide superconductor film formed thereon, wherein said oxide superconductor film comprises atomic monolayers each composed of at least one kind of element of the oxide superconductor, which are deposited substantially in a vertical direction to the substrate so that the pereodicy of the lattice structure of the oxide superconductor is substantially maintained, and at an intermediate portion of the oxide superconductor film, at least a part of the atoms of the oxide superconductor is substituted by other element in the lattice structure of the oxide superconductor to form a non-superconductor interlayer, and the pereodicy of the lattice structure of the oxide superconductor film is substantially maintained across the interface between the oxide superconductor and said non-superconductor interlayer.

Abstract: The invention relates to a structured superconductive track and a process for making it from epitaxial high temperature superconductor (HTSC) layers using lift off technique, in which a HTSC track deposited on an elevated substrate region is surrounded by an insulating layer of doped HTSC lying on a lower substrate region, and the substrate region with the superconductive track formed thereon is elevated such that the superconductive track is isolated from the insulating layer.

Abstract: A method for forming an oxide superconductor thin film having different thickness portions, in a process for manufacturing a superconductor device, includes the step of forming an oxide superconductor thin film having a uniform thickness on a substrates. A portion of the oxide superconductor thin film is etch-removed so that the oxide superconductor thin film has a thin thickness portion. Preferably, before the etching, the oxide superconductor thin film is coated with a metal layer, and the oxide superconductor thin film and the metal layer are etched together by means of a physical dry etching process.

Abstract: A novel method for fabricating nanometer geometry electronic devices is described. Such Josephson junctions can be accurately and reproducibly manufactured employing photolithographic and direct write electron beam lithography techniques in combination with aqueous etchants. In particular, a method is described for manufacturing planar Josephson junctions from high temperature superconducting material.

Abstract: A manufacturing method of Josephson devices is described. A superconducting ceramic film is deposited on a non-conductive surface and partly spoiled in order to form a barrier film by which two superconducting regions is separated. The spoiling is performed by adding a spoiling element into the ceramic film by ion implantation.

Abstract: A hysteretic high-T.sub.c trilayer Josephson junction, and a method of forming the same are disclosed. The junction includes lower and upper high T.sub.c superconducting cuprate films separated by a barrier layer, where the thin films each include a molecular junction layer adjacent the barrier layer which is characterized by a high-T.sub.c cuprate stoichiometry and crystal structure, and a flat two-dimensional surface, as evidenced by its electron diffraction pattern using reflected high-energy electron diffraction. The junction and barrier layers in the junction are formed by atomic layer-by-layer deposition.

Abstract: A Josephson junction device comprising a single crystalline substrate including principal surface, a layer of the same material as the substrate formed on the principal surface of the substrate so as to form a step on the principal surface, and an oxide superconductor thin film formed on the principal surface of the substrate. The oxide superconductor thin film includes a first and a second superconducting portions respectively positioned above and below the step, which are constituted of single crystals of the oxide superconductor, a junction portion between the first and the second superconducting portions, which is constituted of a single crystal of the oxide superconductor of which crystal orientation is different from those of the first and second superconducting portions, and grain boundaries between the first superconducting portion and the junction portion and between the second superconducting portion and the junction portion, which constitute one weak link of the Josephson junction.

Abstract: The disclosure relates to a Josephson junction formed by a non-superconducting barrier between two superconducting films of the (R) BaCuO (R=rare earth) group. In order to take advantage of the greater coherence length of superconductors along the CuO planes, i.e. perpendicularly to the long axis "c" of the crystal unit cell, the superconducting film is oriented so that the axis "c" is parallel to the plane of the junction. The device can be applied to Josephson junctions and to SQUIDs.

Abstract: A novel method of producing weak-link grain boundary Josephson junctions in high temperature superconducting thin films is disclosed. These junctions are reliably and reproducibly formed on uniform planar substrates (10) by the action of a seed layer (40) placed intermediate the substrate (10) and the superconductor film (20). The superconductor film (22) grown atop the seed (42) is misoriented from the rest of the film (24) by an angle between 5.degree. and 90.degree.. The grain boundary (30) so formed acts as a high quality weak-link junction for superconductor devices. The performance of these junctions can be improved by the addition of buffer layers (50, 60) between the substrate (10) and the superconductor film (20).

Abstract: A method of manufacture of thin film devices involves the sputtering of an epitaxial barrier layer (11) of a metallic oxide such as magnesia on to which a further epitaxial thin film (12) is deposited. The substrate is preferably alumina and the thin film may be a high temperature superconductive compound of yttrium, barium, copper and oxygen.

Abstract: An ion beam is irradiated to an oxide superconducting thin film formed on a substrate to disturb the crystal structure of the superconducting thin film and thus forming a damaged layer. The damaged layer has higher solubility in a halogen solution has a faster etching rate than other portions. Then, the superconducting thin film is etched by using a halogen solution to remove the damaged layer and form a groove at that portion. As a result, a groove of a desired form can be provided efficiently.

Abstract: A portion of a sufficiently thick insulating layer formed on a substrate is removed so that a recessed device region is formed and surrounded by masking wall portions left at both ends of the recessed device region. A first oxide superconducting thin film is deposited at angle of 30.degree. to the substrate so as to ensure that a c-axis oriented oxide superconducting thin film grows in such a way that a portion of the recessed device region is masked by one of the masking wall portions so that no thin film grows over the masked portion of the recessed device region. Then, another oxide superconducting thin film is deposited at angle of -30.degree.

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: A Josephson break junction device suitable for highly sensitive electronic detecting systems. A superconductor film such as YBa.sub.2 Cu.sub.3 O.sub.7 is deposited on a substrate such as a simple-crystal MgO. The film is fractured across a narrow strip by at least one indentation in the substrate juxtaposed from the strip to form a break junction. A transducer is affixed to the substrate for applying a bending movement to the substrate to regulate the distance across the gap formed at the fracture to produce a Josephson turned junction effect. Alternatively, or in addition to the transducer, a bridge of a novel metal is applied across the gap to produce a weak-link junction.