Patents by Inventor Tatsuo Itagaki

Tatsuo Itagaki 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: 5175608
    Abstract: A thin film forming method and apparatus, wherein a negative voltage is applied alternately to a target and a substrate to perform film formation and reverse sputter alternately. Further, a coil is mounted between the target and the substrate and a high frequency current is made to flow therethrough to generate plasma. A negative base voltage smaller in absolute value than that during sputter may be applied to the substrate to make Ar ions flow into the substrate while it is subjected to reverse sputter. Thus, a film whose step coverage is 0.3 or more is possible. It becomes also possible to maintain a stable discharge and perform reverse sputter in a high vacuum region. The pressure of an Ar atmosphere may be lowered to 10.sup.-3 Torr or less. An aluminum wiring film whose peak value of x-ray diffraction strength at a (111) plane is 150 Kcps or more is possible.
    Type: Grant
    Filed: August 30, 1990
    Date of Patent: December 29, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Masayasu Nihei, Jin Onuki, Yasushi Koubuchi, Kunio Miyazaki, Tatsuo Itagaki
  • Patent number: 5061985
    Abstract: With the reduction in the size of semiconductor integrated circuit devices, there have been increases in the resistance at the contact portions of metal interconnections and in the incidence of contact failure. To solve these problems, the present invention provides a novel interconnection structure.
    Type: Grant
    Filed: June 12, 1989
    Date of Patent: October 29, 1991
    Assignees: Hitachi, Ltd., Hitachi Microcomputer Engineering Ltd.
    Inventors: Hideo Meguro, Yoshiaki Yoshiura, Tatsuo Itagaki, Ken Uchida, Tsuneo Satoh, Seiichi Ichihara, Koichi Nagasawa
  • Patent number: 5051812
    Abstract: A semiconductor device having a high reliability wiring conductor structure applicable to DRAMs and SRAMs.The semiconductor device of the present invention is characterized by comprising a first wiring conductor film wherein a specific resistance is 5.about.15.mu..OMEGA.cm and an allowable current density is 1.times.10.sup.6 .about.1.times.10.sup.8 A/cm.sup.2 ; a second wiring conductor film having a laminated layer structure formed of a layer of high fusing point and low resistance material and a layer of an Al based alloy; and a plug composed of a high fusing point and low resistance material, electrically connecting to the first wiring conductor film and the second wiring conductor film. Thus, a semiconductor device showing almost no increase in electrical resistance in a wiring conductor film due to electromigration even after subjecting to a large current is provided.
    Type: Grant
    Filed: July 12, 1990
    Date of Patent: September 24, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Jin Onuki, Masayasu Nihei, Yasushi Koubuchi, Motoo Suwa, Shinichi Fukada, Katsuhiko Shiota, Kunio Miyazaki, Tatsuo Itagaki, Jun Sugiura
  • Patent number: 5019891
    Abstract: A semiconductor device and the method of fabricating the semiconductor device include a semiconductor substrate and a plurality of conductor films formed on the substrate. Each of the conductor films is made of aluminum alloy including at least one element selected from palladium and platinum and, more preferably, further including at least one element selected from lithium, beryllium, magnesium, manganese, iron, cobalt, nickel, copper, lanthanum, cerium, chromium hafnium, zirconium, cadmium, titanium, tungsten, vanadium, tantalum, and niobium, with a protective film which includes oxide of the selected one of palladium and platinum being formed on the side wall of the conductor film.
    Type: Grant
    Filed: January 12, 1989
    Date of Patent: May 28, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Jin Onuki, Yasushi Koubuchi, Shinichi Fukada, Katuhiko Shiota, Kunio Miyazaki, Tatsuo Itagaki, Genji Taki
  • Patent number: 4999096
    Abstract: A thin film forming method and apparatus is provided, wherein a negative voltage is applied alternately to a target and a substrate to perform film formation and reverse sputter alternately. Further, a coil is mounted between the target and the substrate and a high frequency current is made to flow therethrough to generate plasma. A negative base voltage smaller in absolute value than that during sputter may be applied to the substrate to make a fraction of Ar ions to flow into the substrate while it is subjected to reverse sputter. Thus, a film whose step coverage is 0.3 or more is possible. It becomes also possible to hold stable discharge and reverse sputter at a high vacuum region. The pressure of an Ar atmosphere may be lowered to 10.sup.-3 Torr or less. A film whose peak value of x-ray diffraction strength in the (111) plane is 150 Xcps or more is possible.
    Type: Grant
    Filed: June 29, 1988
    Date of Patent: March 12, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Masayasu Nihei, Jin Onuki, Yasushi Koubuchi, Kunio Miyazaki, Tatsuo Itagaki