Patents by Inventor Michitomo Iiyama

Michitomo Iiyama has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5466664
    Abstract: A method of manufacturing a superconducting device involves forming a thin film on the surface of a substrate, forming a superconducting gate electrode on a portion of the thin film, etching the portions of the thin film using the gate electrode as a mask thereby providing a superconducting channel under the gate, forming a step portion on the superconducting channel and under the gate, converting the oxide portion of the step portion into a gate insulation portion by heating the substrate in a vacuum, forming a second oxide superconducting film on the exposed surface of the channel so that superconducting source and drain electrodes are formed on each side of the gate such that the drain and source have a thickness greater than that of the channel and are electrically isolated from the gate electrode.
    Type: Grant
    Filed: July 26, 1994
    Date of Patent: November 14, 1995
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Hiroshi Inada, Takao Nakamura, Michitomo Iiyama
  • Patent number: 5464812
    Abstract: A thin film of oxide superconductor consisting of more than two portions (10, 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 the thin film of oxide superconductor is deposited on a thin under-layer (4, 100) which facilitates crystal growth of the selected portion 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.
    Type: Grant
    Filed: February 24, 1994
    Date of Patent: November 7, 1995
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Hiroshi Inada, Michitomo Iiyama
  • Patent number: 5462918
    Abstract: A superconducting device has a stacked structure including a first superconducting layer, a first insulating layer, a second superconducting layer, a second insulating layer and a third superconducting layer stacked on a substrate in this given order. The stacked structure has an end surface portion extending from the first insulating layer to the second insulating layer. A fourth superconducting layer is formed to cover the end surface of the stacked structure. A third insulating layer separates the stacked structure end surface and the fourth superconducting layer. The fourth superconducting layer is electrically connected to the first and third superconducting layers but is isolated from the second superconducting layer by the third insulating layer. The first through fourth superconducting layers are formed of an oxide superconductor thin film.
    Type: Grant
    Filed: May 26, 1994
    Date of Patent: October 31, 1995
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takao Nakamura, Hiroshi Inada, Michitomo Iiyama
  • Patent number: 5462919
    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.
    Type: Grant
    Filed: February 18, 1994
    Date of Patent: October 31, 1995
    Assignee: Sumitomo Electric Industries,Ltd.
    Inventors: So Tanaka, Michitomo Iiyama
  • Patent number: 5447907
    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.
    Type: Grant
    Filed: December 10, 1992
    Date of Patent: September 5, 1995
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takao Nakamura, Hiroshi Inada, Michitomo Iiyama
  • Patent number: 5446015
    Abstract: For manufacturing a superconducting device, a first oxide superconductor thin film having a very thin thickness is formed on a principal surface of a substrate, and a stacked structure of a gate insulator and a gate electrode is formed on a portion of the first oxide superconductor thin film. A second oxide superconductor thin film is grown on an exposed surface of the first oxide superconductor thin film, using the gate electrode as a mask, so that first and second superconducting regions having a relatively thick thickness are formed at opposite sides of the gate electrode, electrically isolated from the gate electrode. A source electrode and a drain electrode are formed on the first and second oxide superconducting regions. The superconducting device thus formed can function as a super-FET.
    Type: Grant
    Filed: February 10, 1994
    Date of Patent: August 29, 1995
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takao Nakamura, Hiroshi Inada, Michitomo Iiyama
  • Patent number: 5446016
    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.
    Type: Grant
    Filed: February 15, 1994
    Date of Patent: August 29, 1995
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: So Tanaka, Takao Nakamura, Michitomo Iiyama
  • Patent number: 5439875
    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.
    Type: Grant
    Filed: November 7, 1994
    Date of Patent: August 8, 1995
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: So Tanaka, Hiroshi Inada, Michitomo Iiyama
  • Patent number: 5434127
    Abstract: For manufacturing a superconducting device, a first c-axis orientated oxide superconductor thin film having a very thin thickness is formed on a principal surface of a substrate, and a stacked structure of a gate insulator and a gate electrode is formed on a portion of the first oxide superconductor thin film. An a-axis orientated oxide superconductor thin film is grown, using the gate electrode as a mask, so that second and third superconducting regions having a relatively thick thickness are formed at both sides of the gate electrode, electrically isolated from the gate electrode. The superconducting device thus formed can functions as a super-FET.
    Type: Grant
    Filed: July 25, 1994
    Date of Patent: July 18, 1995
    Assignee: Sumitomo Electric Industries, ltd.
    Inventors: Takao Nakamura, Hiroshi Inada, Michitomo Iiyama
  • Patent number: 5430012
    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.
    Type: Grant
    Filed: December 2, 1992
    Date of Patent: July 4, 1995
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takao Nakamura, Hiroshi Inada, Michitomo Iiyama
  • Patent number: 5430013
    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.
    Type: Grant
    Filed: October 24, 1994
    Date of Patent: July 4, 1995
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Hiroshi Inada, Michitomo Iiyama
  • Patent number: 5430011
    Abstract: A superconducting thin film formed on a substrate, comprising at least one oxide superconductor layer formed on the principal surface of said substrate and at least one oxide layer formed of an oxide which compensates for crystalline incompleteness at the surface of said oxide superconductor layer, and which is arranged on or under the superconducting layer.
    Type: Grant
    Filed: September 17, 1992
    Date of Patent: July 4, 1995
    Assignee: Sumitomi Electric Industries, Ltd.
    Inventors: So Tanaka, Michitomo Iiyama
  • Patent number: 5423914
    Abstract: The invention provides a film deposition apparatus comprising a vacuum chamber provided with a partitioning means for dividing the vacuum chamber into a first sub-chamber and a second sub-chamber, the partitioning means including an opening for introducing a vacuum conductance for molecular flows between the first sub-chamber and the second sub-chamber so that a pressure difference can be created between the first sub-chamber and the second sub-chamber even when the opening is open. A gate valve is provided on the partitioning means for hermetically closing the opening of the partitioning means so as to shut off the molecular flows between the first sub-chamber and the second sub-chamber.
    Type: Grant
    Filed: November 3, 1994
    Date of Patent: June 13, 1995
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takao Nakamura, Michitomo Iiyama
  • Patent number: 5422497
    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.
    Type: Grant
    Filed: December 22, 1993
    Date of Patent: June 6, 1995
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Mitsuchika Saitoh, Sou Tanaka, Michitomo Iiyama
  • Patent number: 5422490
    Abstract: A focused ion beam implantation apparatus comprises a vacuum chamber, an ion source generating an ion beam, a means for accelerating the ion beam, a means for eliminating unwanted ion species in the ion beam, and a means for focusing the ion beam on a target. The apparatus further includes a means for scanning the ion beam relative to the target and means for inclining the ion beam relative to the target.
    Type: Grant
    Filed: June 29, 1993
    Date of Patent: June 6, 1995
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takao Nakamura, Michitomo Iiyama
  • Patent number: 5416072
    Abstract: A superconducting device has a superconducting channel formed of an oxide superconductor on the principal surface of a substrate. A source electrode and a drain electrode likewise formed of oxide superconductor, are electrically connected by the channel to provide for superconducting current flow. A superconducting gate electrode is isolated by a side insulating region which completely covers each of opposite side surfaces of the gate electrode. The relative thicknesses of both the source and drain electrodes are much greater than that of the channel thickness. The superconducting channel and the gate insulator are both formed by one oxide thin film, and in a preferred embodiment, the gate electrode likewise is provided by the same film which forms the gate insulator and channel.
    Type: Grant
    Filed: July 26, 1993
    Date of Patent: May 16, 1995
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Hiroshi Inada, Takao Nakamura, Michitomo Iiyama
  • Patent number: 5413982
    Abstract: A superconducting device comprising a substrate having a principal surface, a non-superconducting oxide layer having a similar crystal structure to that of the oxide superconductor, an extremely thin superconducting channel formed of a c-axis oriented oxide superconductor thin film on the non-superconducting oxide layer, a superconducting source region and a superconducting drain region formed of an a-axis oriented oxide superconductor thin film at the both sides of the superconducting channel separated from each other, which are electrically connected each other by the superconducting channel, so that superconducting current can flow through the superconducting channel between the superconducting source region and the superconducting drain region, and a gate electrode of a material which includes silicon through a gate insulator on the superconducting channel for controlling the superconducting current flowing through the superconducting channel, in which the gate electrode is embedded between the supercondu
    Type: Grant
    Filed: December 14, 1992
    Date of Patent: May 9, 1995
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Hiroshi Inada, So Tanaka, Michitomo Iiyama
  • Patent number: 5408108
    Abstract: A superconducting device comprises a substrate having a principal surface and a non-superconducting oxide layer having a similar crystal structure to that of the oxide superconductor, which has a projection at its center portion. A superconducting source region and a superconducting drain region formed of an .alpha.-axis oriented oxide superconductor thin film are positioned at the both sides of the projection of the non-superconducting oxide layer separated from each other and an extremely thin superconducting channel formed of a c-axis oriented oxide superconductor thin film is positioned on the projection of the non-superconducting oxide layer. The superconducting channel electrically connects the superconducting source region to the superconducting drain region, so that superconducting current can flow through the superconducting channel between the superconducting source region and the superconducting drain region.
    Type: Grant
    Filed: December 14, 1992
    Date of Patent: April 18, 1995
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takao Nakamura, Michitomo Iiyama, Hiroshi Inada
  • Patent number: 5407903
    Abstract: For manufacturing a superconducting device, a first c-axis orientated oxide superconductor thin film having a very thin thickness is formed on a principal surface of a substrate, and a stacked structure of a gate insulator and a gate electrode is formed on a portion of the first oxide superconductor thin film. An a-axis orientated oxide superconductor thin film is grown, using the gate electrode as a mask, so that second and third superconducting regions having a relatively thick thickness are formed at both sides of the gate electrode, electrically isolated from the gate electrode. The superconducting device thus formed can functions as a super-FET.
    Type: Grant
    Filed: September 27, 1991
    Date of Patent: April 18, 1995
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takao Nakamura, Hiroshi Inada, Michitomo Iiyama
  • Patent number: 5399546
    Abstract: A superconducting device comprises a substrate, a non-superconducting layer formed in a principal surface of said substrate, an extremely thin superconducting channel formed of an oxide superconductor thin film on the non-superconducting layer. A superconducting source region and a superconducting drain region of a relatively thick thickness are formed of the oxide superconductor at the both sides of the superconducting channel separated from each other but electrically connected through the superconducting channel, so that a superconducting current can flow through the superconducting channel between the superconducting source region and the superconducting drain region.
    Type: Grant
    Filed: November 30, 1992
    Date of Patent: March 21, 1995
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takao Nakamura, Michitomo Iiyama