Patents by Inventor Keizo Sakiyama

Keizo Sakiyama 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: 7208768
    Abstract: A method is provided for forming an electroluminescent device. The method comprises: providing a type IV semiconductor material substrate; forming a p+/n+ junction in the substrate, typically a plurality of interleaved p+/n+ junctions are formed; and, forming an electroluminescent layer overlying the p+/n+ junction(s) in the substrate. The type IV semiconductor material substrate can be Si, C, Ge, SiGe, or SiC. For example, the substrate can be Si on insulator (SOI), bulk Si, Si on glass, or Si on plastic. The electroluminescent layer can be a material such as nanocrystalline Si, nanocrystalline Ge, fluorescent polymers, or type II–VI materials such as ZnO, ZnS, ZnSe, CdSe, and CdS. In some aspect, the method further comprises forming an insulator film interposed between the substrate and the electroluminescent layer. In another aspect, the method comprises forming a conductive electrode overlying the electroluminescent layer.
    Type: Grant
    Filed: April 30, 2004
    Date of Patent: April 24, 2007
    Assignee: Sharp Laboratories of America, Inc.
    Inventors: Yoshi Ono, Wei Gao, John F. Conley, Jr., Osamu Nishio, Keizo Sakiyama
  • Patent number: 7027322
    Abstract: There is provided an EPIR device which is excellent in mass productivity and high in practical utility. The EPIR device includes a lower electrode layer, a CMR thin film layer and an upper electrode layer which are laminated in this order on any of various substrates. A Pt polycrystal thin film 10 forming the lower electrode layer includes columnar Pt crystal grains 10A, 10B, 10C, . . . and over 90% of these crystal grains is oriented to a (1 1 1) face. Columnar PCMO crystal grain groups 20A, 20B, 20C, . . . are respectively locally grown epitaxially on the respective outermost surfaces of the Pt crystal grains 10A, 10B, 10C, . . . . Then, the crystal faces of the crystal grains included in the PCMO crystal grain groups 20A, 20B, 20C, . . . and vertical in the substrate surface normal direction are any one of (1 0 0)p, (1 1 0)p and (1 1 1)p planes.
    Type: Grant
    Filed: March 2, 2004
    Date of Patent: April 11, 2006
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Toshimasa Suzuki, Yuji Nishi, Masayuki Fujimoto, Nobuyoshi Awaya, Kohji Inoue, Keizo Sakiyama
  • Publication number: 20050253136
    Abstract: A method is provided for forming an electroluminescent device. The method comprises: providing a type IV semiconductor material substrate; forming a p+/n+ junction in the substrate, typically a plurality of interleaved p+/n+ junctions are formed; and, forming an electroluminescent layer overlying the p+/n+ junction(s) in the substrate. The type IV semiconductor material substrate can be Si, C, Ge, SiGe, or SiC. For example, the substrate can be Si on insulator (SOI), bulk Si, Si on glass, or Si on plastic. The electroluminescent layer can be a material such as nanocrystalline Si, nanocrystalline Ge, fluorescent polymers, or type II-VI materials such as ZnO, ZnS, ZnSe, CdSe, and CdS. In some aspect, the method further comprises forming an insulator film interposed between the substrate and the electroluminescent layer. In another aspect, the method comprises forming a conductive electrode overlying the electroluminescent layer.
    Type: Application
    Filed: April 30, 2004
    Publication date: November 17, 2005
    Inventors: Yoshi Ono, Wei Gao, John Conley, Osamu Nishio, Keizo Sakiyama
  • Publication number: 20050040482
    Abstract: There is provided an EPIR device which is excellent in mass productivity and high in practical utility. The EPIR device includes a lower electrode layer, a CMR thin film layer and an upper electrode layer which are laminated in this order on any of various substrates. A Pt polycrystal thin film 10 forming the lower electrode layer includes columnar Pt crystal grains 10A, 10B, 10C, . . . and over 90% of these crystal grains is oriented to a (1 1 1) face. Columnar PCMO crystal grain groups 20A, 20B, 20C, . . . are respectively locally grown epitaxially on the respective outermost surfaces of the Pt crystal grains 10A, 10B, 10C, Then, the crystal faces of the crystal grains included in the PCMO crystal grain groups 20A, 20B, 20C, . . . and vertical in the substrate surface normal direction are any one of (1 0 0)p, (1 1 0)p and (1 1 1)p planes.
    Type: Application
    Filed: March 2, 2004
    Publication date: February 24, 2005
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Toshimasa Suzuki, Yuji Nishi, Masayuki Fujimoto, Nobuyoshi Awaya, Kohji Inoue, Keizo Sakiyama
  • Patent number: 6753562
    Abstract: A spin transistor employing the ferromagnetic semiconductor/semiconductor heterojunction is disclosed. The ferromagnetic semiconductor layers form heterojunctions directly on the source and drain of a regular field effect transistor. Using room temperature ferromagnetic semiconductor materials such as iron doped titanium oxide, the spin transistor can have improved spin injection efficiency due to the conductance matching of the ferromagnetic semiconductor with the semiconductor source and drain. The spin transistor further comprises writing plates to modify the magnetic polarization of the ferromagnetic layers to provide memory states. The spin transistor can be used as a memory cell in a magnetic random access memory with potentially large memory signal by utilizing the magnetic moment induced resistivity change.
    Type: Grant
    Filed: March 27, 2003
    Date of Patent: June 22, 2004
    Assignee: Sharp Laboratories of America, Inc.
    Inventors: Sheng Teng Hsu, Jinke Tang, Keizo Sakiyama
  • Patent number: 6352899
    Abstract: A method is provided for forming silicided source/drain electrodes in active devices in which the electrodes have very thin junction regions. In the process, adjacent active areas are separated by isolation regions, typically by LOCOS isolation, trench isolation or SOI/SIMOX isolation. A contact material, preferably silicide, is deposited over the wafer and the underling structures, including gate and interconnect electrodes. The silicide is then planed away using CMP, or another suitable planing process, to a height approximate the height of the highest structure. The silicide is then electrically isolated from the electrodes, using an etch back process, or other suitable process, to lower the silicide to a height below the height of the gate or interconnect electrode. The wafer is then patterned and etched to remove unwanted silicide.
    Type: Grant
    Filed: February 3, 2000
    Date of Patent: March 5, 2002
    Assignee: Sharp Laboratories of America, Inc.
    Inventors: Keizo Sakiyama, Sheng Teng Hsu
  • Patent number: 5965942
    Abstract: In a semiconductor memory device, a tantalum silicon nitride film or hafnium silicon nitride film is provided, as a diffusion barrier layer, between a polysilicon plug which electrically connects a source/drain region to a lower platinum electrode of a capacitor, formed on a silicon substrate, and the lower platinum electrode.The tantalum silicon nitride film has a composition of Ta.sub.X Si.sub.1-X N.sub.Y wherein 0.75 .ltoreq.X.ltoreq.0.95 and 1.0 .ltoreq.Y.ltoreq.1.1.The hafnium silicon nitride film has a composition of Hf.sub.X Si.sub.1-X N.sub.Y wherein 0.2<X<1.0 and 0<Y<1.0.
    Type: Grant
    Filed: May 6, 1997
    Date of Patent: October 12, 1999
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yasuyuki Itoh, Shigeo Onishi, Jun Kudo, Keizo Sakiyama
  • Patent number: 5962889
    Abstract: In the nonvolatile semiconductor memory including a memory cell array having memory cells arranged in a matrix of the present invention, the memory cell array includes: a semiconductor substrate; a tunnel oxide film formed on the semiconductor substrate; floating gates formed on the tunnel oxide film; first insulating films formed on the floating gates; and control gates formed on the first insulating films, wherein each of the floating gates includes a first polysilicon film and second polysilicon films, the second polysilicon films being formed on both sides of the first polysilicon film, second insulating films are formed on the tunnel oxide film between the first polysilicon films, the second insulating films having a predetermined thickness which is thinner than that of the first polysilicon films, and the second polysilicon films are formed on the second insulating films.
    Type: Grant
    Filed: July 31, 1996
    Date of Patent: October 5, 1999
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshimitsu Yamauchi, Masanori Yoshimi, Shinichi Sato, Keizo Sakiyama
  • Patent number: 5776356
    Abstract: A method for etching a ferroelectric film made of a compound containing lead of the present invention, includes the steps of: forming an insulating film, metal films, and a ferroelectric film on a substrate in this order; forming an etching resistant film on the ferroelectric film, followed by patterning; and etching the ferroelectric film with a mixed gas containing an inert gas and a halogen gas or a halogenated gas as an etching gas, using the patterned etching resistant film as an etching mask.
    Type: Grant
    Filed: February 15, 1995
    Date of Patent: July 7, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Seiichi Yokoyama, Yasuyuki Itoh, Shigeo Onishi, Jun Kudo, Keizo Sakiyama, Hitoshi Urashima
  • Patent number: 5515984
    Abstract: A method for etching a Pt film of the present invention includes the steps of: forming an etching resistant film on a Pt film, followed by patterning; etching the Pt film by using as an etching mask the etching resistant film and by using, as an etching gas, a mixed gas containing oxygen gas and chlorine gas or chloride gas, during which layers made of PtCl.sub.x O.sub.y or a mixture containing PtCl.sub.x and PtO.sub.y are formed on side walls of the etching resistant film and the Pt film; and removing the layers made of PtCl.sub.x O.sub.y or the mixture containing PtCl.sub.x and PtO.sub.y with an acid by wet etching after the etching step.
    Type: Grant
    Filed: January 24, 1995
    Date of Patent: May 14, 1996
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Seiichi Yokoyama, Yasuyuki Ito, Shigeo Onishi, Jun Kudo, Keizo Sakiyama
  • Patent number: 5420077
    Abstract: A method for a wiring layer on a semiconductor substrate wherein a contact hole for a wiring layer is formed by laminating a lower insulating layer and an etching barrier layer on the semiconductor substrate providing electrodes via a gate insulating film, forming a hole in the etching barrier layer using a first mask pattern having a hole pattern in which a diameter of the hole thereof is larger than that of the contact hole to be formed, laminating an upper insulating layer and a second mask pattern having a hole pattern in which a diameter of the hole thereof is substantially the same as that of the contact hole, subjecting the lower and upper insulating layers and the gate insulating film to an isotropic etching and an anisotropic etching, utilizing the second mask pattern, thereby forming a contact hole having no exposure of the etching barrier layer at the side of wall of the contact hole.
    Type: Grant
    Filed: February 22, 1993
    Date of Patent: May 30, 1995
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Satoshi Saito, Keizo Sakiyama
  • Patent number: 5416735
    Abstract: Random access memory includes a pair of metal oxide semiconductor (MOS) transistors which are connected to each other by a common impurity diffusion region, and a capacitor which is formed of ferroelectric film acting as a capacitor layer and is connected to the impurity diffusion region, one of the pair of MOS transistors being connected to a bit line and a word line.
    Type: Grant
    Filed: February 22, 1994
    Date of Patent: May 16, 1995
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Shigeo Onishi, Kenichi Tanaka, Keizo Sakiyama
  • Patent number: 5414653
    Abstract: A non-volatile random access memory comprising a plurality of unit cells each of which includes; a transistor composed of source/drain and gate electrodes, a ferroelectric capacitor connected to either of the source/drain electrodes and a high load device connected to both of the ferroelectric capacitor and the source/drain electrodes being connected to the ferroelectric capacitor.
    Type: Grant
    Filed: October 6, 1993
    Date of Patent: May 9, 1995
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Shigeo Onishi, Kazuya Ishihara, Kenichi Tanaka, Keizo Sakiyama
  • Patent number: 5411904
    Abstract: A nonvolatile random access memory comprising a nonvolatile random access memory unit having on a substrate an EEPROM having a tunnel oxide film and a floating gate, and a DRAM linked to the EEPROM, a thermal oxide film being selectively formed between the EEPROM and another EEPROM adjacent thereto, the tunnel regions of the respective EEPROMs being provided as self-aligned with the respective ends of the thermal oxide film and positioned at the respective ends of an impurity ion implantation pattern for use in forming a source region of the EEPROMs.
    Type: Grant
    Filed: April 25, 1994
    Date of Patent: May 2, 1995
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshimitsu Yamauchi, Kenichi Tanaka, Keizo Sakiyama, Akitsu Ayukawa
  • Patent number: 5401993
    Abstract: A non-volatile memory includes a single transistor having a semiconductor substrate, source and drain diffusion layers formed on a surface of the semiconductor substrate, and a gate electrode provided on the semiconductor substrate with a gate insulating film interposed between them. The non-volatile memory further includes a programmable insulating film provided in self-alignment between the gate electrode and at least one of the source and drain diffusion layers and the programmable insulating film is broken down by a voltage applied to the gate electrode so as to execute programming.
    Type: Grant
    Filed: June 30, 1993
    Date of Patent: March 28, 1995
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshimitsu Yamauchi, Kenichi Tanaka, Keizo Sakiyama
  • Patent number: 5383151
    Abstract: A dynamic random access memory includes a plurality of DRAM cell units having a bit contact region and DRAM cells formed on an active region, wherein the DRAM cells each comprised of a transistor and a capacitor connected to the transistor are arranged symmetrically to the right and left sides in a bit contact connected with the active region to form the DRAM cell unit; and the DRAM cell units are arranged with a prescribed pitch in the direction of X and arranged in the direction of Y shifted with one third of the pitch toward the direction of X.
    Type: Grant
    Filed: August 2, 1993
    Date of Patent: January 17, 1995
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Shigeo Onishi, Kenichi Tanaka, Keizo Sakiyama
  • Patent number: 5357460
    Abstract: A semiconductor memory device which comprises unit memory cells each including two transistors each having a source/drain region and a gate electrode and one capacitor having a capacitor dielectric film, an upper electrode and a lower electrode, the gate electrode of each transistor being connected to a common word line, one source/drain region of each transistor being connected to a bit line and a reversed bit line respectively and the other source/drain region being connected to the upper electrode and the lower electrode respectively, and the bit line, the reversed bit line and the word line being disposed under the lower electrode of the capacitor.
    Type: Grant
    Filed: May 27, 1992
    Date of Patent: October 18, 1994
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tatsushi Yusuki, Shigeo Onishi, Kenichi Tanaka, Keizo Sakiyama, Katsuji Iguchi
  • Patent number: 5331181
    Abstract: A non-volatile semiconductor memory providing a semiconductor substrate including source and drain diffusion regions and a gate electrode, and an insulating film which is at least provided on the semiconductor substrate just below the gate electrode and has a smaller dielectric breakdown strength on the source side than on the drain side, wherein the insulating film is comprised of a laminated film having a multilayer structure on the drain side and a single-layer film or multilayer film which is broken down at a smaller voltage on the source side than on the drain side, and a predetermined voltage is applied to break down the single-layer film or multilayer film on the source side, so that data can electrically be written only once.
    Type: Grant
    Filed: June 25, 1993
    Date of Patent: July 19, 1994
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kenichi Tanaka, Yoshimitsu Yamauchi, Keizo Sakiyama
  • Patent number: 5299151
    Abstract: A method is provided for writing into a semiconductor memory which includes a MOS transistor formed on a semiconductor substrate and an anti-fuse formed of an insulating film and an upper electrode on a drain of the MOS transistor. The method includes the steps of applying a first voltage between the upper electrode of the anti-fuse and a source of the MOS transistor to cause dielectric breakdown of the insulating film of the anti-fuse, with the MOS transistor turned on; and applying a second voltage between the upper electrode of the anti-fuse and the semiconductor substrate so that a larger amount of current flows than the amount of current required for breaking down the insulating film of the anti-fuse.
    Type: Grant
    Filed: June 18, 1991
    Date of Patent: March 29, 1994
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hiroshi Ishihara, Kenichi Tanaka, Keizo Sakiyama
  • Patent number: 5299152
    Abstract: A semiconductor device includes memory cells each of which include a plurality of groups of an anti-fuse and a transistor connected in series; a capacitor including first and second electrodes, with the first electrode connected to a bit line of the memory cell; a first switch connected between the bit line and a power source; a second switch connected between the power source and the second electrode of the capacitor; and a third switch connected between the second electrode of the capacitor and a ground. A specific memory cell is selected out of the memory cells, and a superposed supply voltage is applied through the capacitor to the anti-fuse of the specific memory by turning on and/or off the first through third switches, so that a storage of information in the memory cell can be performed.
    Type: Grant
    Filed: January 28, 1992
    Date of Patent: March 29, 1994
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hiroshi Ishihara, Kenichi Tanaka, Keizo Sakiyama