Nippon Telegraph and Telephone Public Corporation

Nippon Telegraph and Telephone Corporation

Nippon Tsushin Kogyo Kabushiki Kaisha

Toshiaki Murakami

Kazuyuki Moriwaki

Minoru Suzuki

Takahiro Inamura

Yoichi Enomoto

Shigeru Waku

Toshiaki Fujishiro

Takashi Inukai

Akira Demura

Youichi Enomoto

In a method of manufacturing a thin film of a compound oxide, different types of materials for forming the compound oxide are evaporated in vacuum. The evaporated materials are heated and deposited on a substrate to form a thin film. An oxygen ion beam having energy of 10 to 200 eV is implanted in the thin film which is being formed on the substrate. Alignment of the constituting elements is performed on the basis of a substrate temperature and energy of the oxygen ion beam, thereby causing epitaxial growth.

Method of manufacturing thin compound oxide film and apparatus for

A photodetecting device having Josephson junctions, comprises an insulating substrate, a polycrystalline superconductor film formed on the insulating substrate such that Josephson junctions are formed at grain boundaries, the superconductor film having a first region subjected to light illumination, and second and third regions formed contiguously at both sides of the first region such that a width of each of the second and third regions is wider than that of the first region, a bias circuit for supplying a predetermined bias current between the second and third regions, and an output circuit for detecting a change in voltage between the second and third regions, one terminal of said bias circuit and one terminal of said output circuit being commonly grounded, wherein the superconductor film comprises BaPb.sub.1-x Bi.sub.x O.sub.3 (where 0.05.ltoreq.x&lt;0.32) having an I-V characteristic of weak link type under temperature condition less than transition temperature of said BaPb.sub.1-x Bi.sub.x O.sub.3. This simple photodetecting device can detect an optical signal at high speed with high sensitivity.

Photodetecting device

A photodetecting device having Josephson junctions, comprises an insulating substrate, a polycrystalline superconductor film formed on the insulating substrate such that Josephson junctions are formed at grain boundaries, the superconductor film having a first region subjected to light illumination, and second and third regions formed contiguously at both sides of the first region such that a width of each of the second and third regions is wider than that of the first region, an input circuit for supplying a predetermined bias current between the second and third regions, and an output circuit for detecting a change in voltage between the second and third regions, one terminal of said input circuit and one terminal of said output circuit being commonly grounded, wherein the superconductor film comprises BaPb.sub.1-x Bi.sub.x O.sub.3 (where 0.32.ltoreq.x.ltoreq.0.35). This simple photodetecting device can detect an optical signal at high speed with high sensitivity.

Photodetecting device having Josephson junctions

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&gt;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).

Oxide superconductor Josephson junction and fabrication method therefor

A process for producing ceramics to be used as substrates and packages of semiconductor devices, which having a thermal expansion coefficient close to that of silicon used as chip or wafer material of large scale integrations and a mechanical strength and thermal conductivity equal to those of alumina, wherein zircon and clays such as kaolin, ball clay and the like and an additive of one of Li.sub.2 O, TiO.sub.2 and ZnO and another of CoO, Co.sub.2 O.sub.3, Co.sub.3 O.sub.4 and MgO are mixed, molded and fired.

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Mito, Japan

Toshiaki Murakami