Patents by Inventor Maho Ushikubo

Maho Ushikubo 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: 6197600
    Abstract: A ferroelectric thin film includes: a bismuth oxide polycrystal thin film constituting a buffer layer, and a bismuth-based layered compound thin film represented by the formula: Bi2Am-1BmO3m+3 wherein A is an atom selected from the group consisting of Na, K, Pb, Ca, Sr, Ba and Bi; B is an atom selected from the group consisting of Fe, Ti, Nb, Ta, W and Mo; and m is an integer of 1 or more. The bismuth oxide polycrystal thin film and the bismuth-based layered compound thin film are formed into a single-phase.
    Type: Grant
    Filed: May 5, 1998
    Date of Patent: March 6, 2001
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takeshi Kijima, Maho Ushikubo, Hironori Matsunaga
  • Patent number: 6162293
    Abstract: A method for manufacturing a ferroelectric thin film having a layered perovskite crystal structure of the general formula: Bi.sub.2 A.sub.m-1 B.sub.m O.sub.3m+3, wherein A is selected from the group consisting of Na.sup.1+, K.sup.1+, Pb.sup.2+, Ca.sup.2+, Sr.sup.2+, Ba.sup.2+ and Bi.sup.3+, B is selected from the group consisting of Fe.sup.3+, Ti.sup.4+, Nb.sup.5+, Ta.sup.5+, W.sup.6+ and Mo.sup.6+, and m represents an integer of 1 or larger, which comprises introducing into a film formation chamber where a substrate is set, gaseous starting materials inclusive of oxygen gas for forming the ferroelectric thin film in which the flow rate of oxygen gas as one component of the gaseous starting materials is controlled to an arbitrary value necessary for the formation of the ferroelectric thin film having a desired orientation while the pressure inside the film formation chamber and the total flow rate of the gaseous starting materials and an optionally introduced carrier gas are maintained constant.
    Type: Grant
    Filed: December 18, 1997
    Date of Patent: December 19, 2000
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takeshi Kijima, Akira Okutoh, Maho Ushikubo, Hironori Matsunaga
  • Patent number: 5998819
    Abstract: A thin ferroelectric film element comprises upper and lower thin electrode films and a thin ferroelectric film formed on a substrate, wherein the thin ferroelectric film comprises at least three layers in which at least one layer has a composition of constituent elements different from those of the other layers and a resistivity higher than that of the other layers, and at least two layers of the others are the same composition of constituent element.
    Type: Grant
    Filed: August 12, 1998
    Date of Patent: December 7, 1999
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Seiichi Yokoyama, Yasuyuki Ito, Maho Ushikubo, Masayoshi Koba
  • Patent number: 5851841
    Abstract: A method for producing a ferroelectric element having a lower electrode layer, a ferroelectric film and an upper electrode layer provided in sequence on the substrate is disclosed. The method comprising the step of applying a metal-contained precursor solution to the surface of the lower electrode layer formed on the substrate, the step of drying the applied precursor solution to remove the solution alone by heating it, a first heat treatment step for heating the dried precursor to form a ferroelectric film, and a second heat treatment step for heating the formed film element in a gas-pressurized atmosphere of lower than 1 atmosphere after forming an upper electrode layer on the ferroelectric film.
    Type: Grant
    Filed: September 13, 1996
    Date of Patent: December 22, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Maho Ushikubo, Yasuyuki Ito, Seiichi Yokoyama, Hironori Matsunaga, Masayoshi Koba
  • Patent number: 5831299
    Abstract: A thin ferroelectric film element comprises upper and lower thin electrode films and a thin ferroelectric film formed on a substrate, wherein the thin ferroelectric film comprises at least three layers in which at least one layer has a composition of constituent elements different from those of the other layers and a resistivity higher than that of the other layers, and at least two layers of the others are the same composition of constituent element.
    Type: Grant
    Filed: March 19, 1997
    Date of Patent: November 3, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Seiichi Yokoyama, Yasuyuki Ito, Maho Ushikubo, Masayoshi Koba
  • Patent number: 5548475
    Abstract: A dielectric thin film device comprising at least an electrode and a dielectric thin film, said dielectric thin film being a laminate of a plurality of layers whose compositions comprise the same kinds of atoms including volatile atom(s) but are different in the content of the volatile atom(s) in at least one layer from the other.
    Type: Grant
    Filed: November 2, 1994
    Date of Patent: August 20, 1996
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Maho Ushikubo, Yasuyuki Itoh