Patents by Inventor Shimpei Iijima

Shimpei Iijima 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: 6096597
    Abstract: In one embodiment, the present invention provides a method of treating a dielectric layer 24. First, the dielectric layer is heated while being subjected to an O.sub.2 plasma. After that, the dielectric layer is heated while being subject to an ozone environment. This method can be useful in forming a capacitor 12 dielectric 24. In turn, the capacitor could be used in a DRAM memory device.
    Type: Grant
    Filed: January 28, 1998
    Date of Patent: August 1, 2000
    Assignee: Texas Instruments Incorporated
    Inventors: Robert Tsu, William R. McKee, Shimpei Iijima, Isamu Asano, Masato Kunitomo, Tsuyoshi Tamaru
  • Patent number: 5296729
    Abstract: There is provided a technique capable of reducing the electrode resistance by widening the effective area of an electrode in a cell for a standard potential supply connected to the memory cell. There is also provided a technique capable of reducing the memory cell area by reducing the area necessary for separation between the electrode in a cell for the standard potential supply and adjacent other electrodes. Two transfer MOS transistors of a first conductivity type and two driver MOS transistors are provided. A conductive layer for fixing the source potential of the driver MOS transistors to standard potential is so disposed above the transfer and driver MOS transistors as to the wholly cover the memory cell. Separation is carried out by using a photo-mask having an optically transparent substrate provided within the same transmissive portion with a pattern of a plurality of so-called phase shifter regions for inversion of the phase of transmitting light.
    Type: Grant
    Filed: October 25, 1991
    Date of Patent: March 22, 1994
    Assignees: Hitachi, Ltd., Hitachi VLSI Engineering Corp.
    Inventors: Toshiaki Yamanaka, Norio Hasegawa, Toshihiko Tanaka, Takashi Hashimoto, Koichiro Ishibashi, Naotaka Hashimoto, Akihiro Shimizu, Yasuhiro Sugawara, Tokuo Kure, Shimpei Iijima, Takashi Nishida, Eiji Takeda
  • Patent number: 5227329
    Abstract: A boron doped amorphous silicon film is formed by CVD under the conditions of a pressure lower than 1 atm and a temperature higher than 200.degree. C. and lower than 400.degree. C. by using at least one of disilane and trisilane, and diborane as source gases. Since the resultant amorphous silicon film can diffuse impurities at a lower temperature than in the case of the polycrystalline silicon film formed by the conventional method, a pn junction much shallower than in the prior art can be formed.
    Type: Grant
    Filed: August 30, 1991
    Date of Patent: July 13, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Kobayashi, Shimpei Iijima, Atsushi Hiraiwa, Nobuyoshi Kobayashi, Takashi Hashimoto, Mitsuo Nanba
  • Patent number: 5200635
    Abstract: The present invention concerns a semiconductor device having a low-resistivity wiring structure. Wirings formed directly on a hill and valley structure result in a thin portion and, in an extreme case, a disconnected portion. This increases the resistivity of wirings on the hill and valley structure and lowers the reliability of the connection. In a case where the wirings are data lines of a memory, with an increased effective length, the resistance and the parasitic capacitance of the data line is greater. The above mentioned problems have been solved by wirings which comprise at least two layers of conductive film including a first conductive film as a lower layer and a second conductive film as an upper layer, and the first conductive layer has a surface moderating or planarizing the hills and valleys in the underlying material.
    Type: Grant
    Filed: April 17, 1991
    Date of Patent: April 6, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Toru Kaga, Shinichiro Kimura, Katsutaka Kimura, Yoshinobu Nakagome, Digh Hisamoto, Yoshifumi Kawamoto, Eiji Takeda, Shimpei Iijima, Tokuo Kure, Takashi Nishida
  • Patent number: 5177773
    Abstract: An X-ray mask comprises an absorber pattern composed of a material capable of absorbing X-ray, a mask substrate for supporting the absorber pattern, composed of a material capable of transmitting X-ray, and a support frame for supporting the mask substrate, wherein the mask substrate is composed of a mask substrate material whose impurity content is suppressed to reduce positional distortions generated by X-ray radiation. Generation of positional distortions by X-ray exposure is inhibited and an arrangement of mask pattern can be ensured with a high precision.
    Type: Grant
    Filed: March 25, 1991
    Date of Patent: January 5, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Hiroaki Oizumi, Kozo Mochiji, Shimpei Iijima
  • Patent number: 5053849
    Abstract: Herein disclosed is a semiconductor device of high density. The semiconductor device having a high density and a microstructure is required to have a high breakdown voltage and a high speed even with a low supply voltage. The semiconductor device comprises: a semiconductor body; a gate insulating film formed over the body; and a MOS transistor having a source/drain region formed in the body and a gate electrode film formed over the gate insulating film. The gate electrode film is composed of two or more films having different etching rates. The gate etching is stopped at the interface of the composite film to form an inverse-T gate electrode structure; and in that an electric conduction is observed between the component films. Thus, the overlap between the gate and the drain can be controlled.
    Type: Grant
    Filed: April 25, 1990
    Date of Patent: October 1, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Ryuichi Izawa, Tokuo Kure, Shimpei Iijima, Eiji Takeda, Yasuo Igura, Akemi Hamada, Atsushi Hiraiwa