Abstract: A self-aligning technique is used to produce small area junctions such as small area Josephson junctions. A base layer having a thickness corresponding to one dimension of the junction is first deposited. An insulating material is then deposited from a source positioned so that the base layer itself masks its edge from the insulator being formed. This procedure coats the base layer with an insulator, but leaves an edge of this layer free of insulation. A junction is then completed on this uncoated edge.

Abstract: This invention relates to granular metal and metal oxide superconducting films formed by ion beam sputter deposition. Illustratively, the films comprise irregularly shaped, randomly oriented, small lead grains interspersed in an insulating lead oxide matrix. The films are hillock-resistant when subjected to thermal cycling and exhibit unusual Josephson-type switching characteristics. Depending on the oxygen content, a film may behave in a manner similar to that of a plurality of series connected Josephson junctions, or the film may have a voltage difference in a direction parallel to a major surface of the film that is capable of being switched from zero voltage difference to a finite voltage difference in response to a current larger than the critical current.

Abstract: This invention is a process for forming electrical conductors in the form of filaments which exhibit properties of electrical superconductivity at ambient or normal room temperature. The process includes the preparation of a molten mixture of conducting and insulator materials, the introduction of the nearly homogeneous mixture between electrodes across which a voltage is applied causing fine filaments to be formed having a diameter within the range of 10 to 1,000 A. The filaments thus formed give almost no resistance to the passage of the electricity therethrough at room temperature thus effectively forming an ambient temperature superconductor.

Abstract: A tunneling Josephson junction is disclosed in which first and second superposed superconducting electrode layers are formed of thin films of oxide superconducting materials having a perovskite structure of BaPB.sub.1-x Bi.sub.x O.sub.3. A barrier layer interposed between these superconducting electrode layers is a thin film of long service life which is stable and breakdown free under heat cycles from room temperature to ultra low temperatures. This film is made of an oxide with perovskite structure which has the same crystal structure and thermal expansion coefficient as those of the first and second superconducting layers for functioning as an insulator or a semiconductor. The oxide with perovskite structure may be BaSnO.sub.3, Ba.sub.1-y Sr.sub.y Pb.sub.1-x Bi.sub.x O.sub.3 (wherein 0.ltoreq.x.ltoreq.0.3, y>0.3) or BaPb.sub.1-x (A.sub.1-y Bi.sub.y)O.sub.3 (wherein A is at least one member selected from the group consisting of V, Nb, Ta and Sb; 0.1.ltoreq.x.ltoreq.0.3; and 0.ltoreq.y.ltoreq.0.5).

Abstract: An improved method of preparing thin film superconducting electrical circuits of niobium or niobium compounds in which a thin film of the niobium or niobium compound is applied to a nonconductive substrate, and covered with a layer of photosensitive material. The sensitive material is in turn covered with a circuit pattern exposed and developed to form a mask of the circuit in photoresistive material on the surface of the film. The unmasked excess niobium film is removed by contacting the substrate with an aqueous etching solution of nitric acid, sulfuric acid and hydrogen fluoride, which will rapidly etch the niobium compound without undercutting the photoresist. A modification of the etching solution will permit thin films to be lifted from the substrate without further etching.

Abstract: A process for forming subminiature bores through very thin layers of insulative material disposed between spaced electrical conductors permits the lining of the conductors by a further conductor of microscopic cross section whose dimensions are readily controlled. The method provides reliable reproduction of weak link conductors for employment in applications such as Josephson superconductive devices.

Abstract: This invention relates to a method of producing a Josephson-effect superconductive junction.The method is characterised in that a superconductive refractory material is applied as a thin and uniform deposit to an insulating substrate, the deposit is defined to give it the form of a bridge between two studs of greater width than the said bridge, and in that the junction at very low temperature is subjected to at least one current pulse, the intensity and duration of which have a value dependent upon the required critical Josephson current.A particular application of the invention is the production of a magnetometer.

Abstract: A relatively thin superconductive magnetic shield, as of lead, is supported from a hollow support structure, as of aluminum or fiberglass by means of a multiplicity of spots of adhesive, as of epoxy, serving to bond the superconducting shield to the support structure. The shield and support structure is then positioned within a reentrant cryostat and cooled to liquid helium temperature to render the shield superconductive. Adjacent edges of the shield material are outwardly flanged and sealed together at the flanged portions, as by welding. The spot pattern of adhesive permits the shield to flex during thermal cycling to relieve strain and prevent fracture thereof while at the same time supporting the shield in a substantially nonmicrophonic manner.

Abstract: A process for forming subminiature bores through very thin layers of insulative material disposed between spaced electrical conductors permits the joining of the conductors by a further conductor of microscopic cross section whose dimensions are readily controlled. The method provides reliable reproduction of weak link conductors for employment in applications such as Josephson superconductive devices.

Abstract: A flame retardant, flexible, solder resistant covercoat has been formulated based on dichloropropyl acrylate.

Abstract: A composite multifilament superconducting structure is provided, which includes an elongated substrate-carrying, longitudinally-directed, sputtered discrete filament of an A-15 type intermetallic superconductor. In a preferable procedure, a plurality of spaced, generally longitudinal grooves are formed on the surface of an elongated filamentary substrate, preferably a metal wire. The walls of the grooves on the substrate surface are shaped to undercut the curvilinear surface of the substrate located between two adjacent grooves so that at least some of the wall portions of the grooves are geometrically shadowed during the subsequent sputtering step in which a superconductor is sputtered onto the substrate. In particular, a film of a suitable superconducting intermetallic compound having A-15 crystalline structure, such as Nb.sub.3 Ge, is thereupon sputtered onto the grooved substrate and deposits at the bottom of the grooves and at the surface portions of the substrate between grooves.

Abstract: A method for fabricating very narrow superconducting metallic lines on a substrate using ion-implantation and etching techniques. The method permits lines to be produced which are much smaller than those fabricated by conventional masking and etching techniques. It makes the fabrication of very small Josephson and other superconducting devices possible. Also since lines are formed in metals, they have high conductivity, so are useful as ordinary conductors at high temperature or when the technique is utilized with non-superconducting materials. The method includes the steps of depositing a selected metal film on a substrate, applying a photoresist or other masking pattern and exposing, etching away the exposed region, ion-implanting the edge of the resulting pattern, removing the photoresist and etching away the unimplanted portion of the metal leaving an ultra-narrow line pattern.

Abstract: A fabrication method for integrated circuits is disclosed wherein a structure is formed on one side of a supporting substrate which provides a ground plane with "X" wiring on one side and "Y" wiring on the other side thereof. The method includes a number of alternative initial planarization steps which permits the resulting device to be substantially planar, thereby allowing it to be used as a substrate for preparation of high density integrated circuits. A first planarization step includes the deposition of a niobium thin film on a doped silicon substrate; the delineation of the desired niobium "X" wiring pattern using well-known photolithographic and etching techniques, leaving the photoresist in place to protect the niobium; the anodization of exposed silicon substrate portions to form silicon dioxide surrounding the niobium to a higher level than the niobium; and the removal of the photoresist.