Patents by Inventor Tsutomu Hayakawa

Tsutomu Hayakawa 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: 7919767
    Abstract: A semiconductor memory device comprises a heater electrode, a phase change portion, a heat insulation portion and an upper electrode. The phase change portion comprises a concave portion and a contact portion. The concave portion is in contact with the heater electrode. The contact portion is formed integrally with the concave portion. The heat insulation portion is formed in the concave portion. The upper electrode is formed on the contact portion and the heat insulation portion so that the heat insulation portion is positioned between the concave portion and the upper electrode.
    Type: Grant
    Filed: June 21, 2007
    Date of Patent: April 5, 2011
    Assignee: Elpida Memory, Inc.
    Inventor: Tsutomu Hayakawa
  • Patent number: 7755075
    Abstract: A phase-change memory device has a different-material contact plug having a first electrically conductive material plug made of a first electrically conductive material, and a second electrically conductive material plug made of a second electrically conductive material having a specific resistance smaller than the first electrically conductive material, the first electrically conductive material plug and the second electrically conductive material plug being buried in a common contact hole. The different-material contact plug is effective for reducing the radiation of heat from a contact plug beneath a phase-change layer. The phase-change memory device also includes an extension electrode layer held in contact with a portion of the bottom surface of the phase-change layer in an area displaced off a position directly above a contact surface through which the phase-change layer and the heater electrode contact each other.
    Type: Grant
    Filed: February 23, 2007
    Date of Patent: July 13, 2010
    Assignee: Elpida Memory, Inc.
    Inventor: Tsutomu Hayakawa
  • Patent number: 7728321
    Abstract: The invention provides a novel structure of a phase change memory device. In the phase change memory device of the invention, an electrode acting as a radiating fin does not exit immediately above a phase change area of a phase change layer (115). A heater electrode (111) and landing electrode layer (113a, 114a) both contact the bottom of the phase change layer (115) made of GST. The landing electrode layer (113a, 114a) contacts the bottom of the phase change layer (115) to partially overlap in a region off from a portion immediately above the contact face (Y) of the phase change layer and heater electrode. The contact electrode (116, 118) is directly connected to the landing electrode layer (113a, 114a) in a portion off from a portion immediately above the heater electrode (111). The phase change layer of GST or the like does not exist immediately below the contact electrode.
    Type: Grant
    Filed: September 11, 2006
    Date of Patent: June 1, 2010
    Assignee: Elipida Memory Inc.
    Inventor: Tsutomu Hayakawa
  • Patent number: 7723717
    Abstract: A semiconductor memory device comprises a heater electrode, a phase change portion, and an upper electrode. The phase change portion is connected to the heater electrode in a first direction. The upper electrode has an upper surface, a lower surface and a hole. The hole pierces the upper electrode between the upper and the lower surfaces in the first direction. The hole has an inner wall, which is connected to the phase change portion in a second direction perpendicular to the first direction.
    Type: Grant
    Filed: July 19, 2007
    Date of Patent: May 25, 2010
    Assignee: Elpida Memory, Inc.
    Inventor: Tsutomu Hayakawa
  • Patent number: 7671360
    Abstract: A phase change memory includes a sidewall insulation film and a heater electrode which are formed in a contact hole formed in an interlayer insulation film on a lower electrode. The heater electrode has a recessed structure. In a recessed area surrounded by the sidewall insulation film, the heater electrode and a phase change film are contacted with each other. A phase change region is formed only in an area contacted with the sidewall insulation film. The sidewall insulation film is an anti-oxidizing insulation film. The phase change region and the heater electrode which are heated to a high temperature upon rewriting are not contacted with the interlayer insulation film as an oxidizing insulation film.
    Type: Grant
    Filed: September 4, 2007
    Date of Patent: March 2, 2010
    Assignee: Elpida Memory, Inc.
    Inventors: Natsuki Sato, Tsutomu Hayakawa
  • Patent number: 7532507
    Abstract: A composite plug 104 is formed, and both a first plug (TiN) 106 and a second plug (W) 108 are disposed in one contact hole; the first plug (TiN) 106 functions as a heater electrode and the second plug (W) 108 functions as a contact plug. This eliminates the need to stack the heater electrode on the contact plug. The resistivities R11 and R12 of the first and second plugs of the composite plug 104 are in a relationship R11>R12.
    Type: Grant
    Filed: January 16, 2007
    Date of Patent: May 12, 2009
    Assignee: Elpida Memory, Inc.
    Inventor: Tsutomu Hayakawa
  • Patent number: 7498601
    Abstract: A phase-change memory device has a phase-change layer, a heater electrode having an end held in contact with the phase-change layer, a contact plug of different kinds of material having a first electrically conductive material plug made of a first electrically conductive material and held in contact with the other end of the heater electrode, and a second electrically conductive material plug made of a second electrically conductive material having a specific resistance smaller than the first electrically conductive material, the first electrically conductive material plug and the second electrically conductive material plug being stacked in one contact hole, the heater electrode and the second electrically conductive material plug being held in contact with each other in overlapping relation to each other, and an electrically conductive layer electrically connected to the second electrically conductive material plug.
    Type: Grant
    Filed: November 27, 2006
    Date of Patent: March 3, 2009
    Assignee: Elpida Memory, Inc.
    Inventors: Tsutomu Hayakawa, Shinpei Iijima
  • Patent number: 7368802
    Abstract: A phase-change memory device has a phase-change layer, a heater electrode having an end held in contact with the phase-change layer, a contact plug of different kinds of material having a first electrically conductive material plug made of a first electrically conductive material and held in contact with the other end of the heater electrode, and a second electrically conductive material plug made of a second electrically conductive material having a specific resistance smaller than the first electrically conductive material, the first electrically conductive material plug and the second electrically conductive material plug being held in contact with each other through at least respective side surfaces thereof, the heater electrode and the second electrically conductive material plug being not in overlapping relation to each other, and an electrically conductive layer electrically connected to the second electrically conductive material plug.
    Type: Grant
    Filed: November 27, 2006
    Date of Patent: May 6, 2008
    Assignee: Elpida Memory, Inc.
    Inventor: Tsutomu Hayakawa
  • Publication number: 20080067490
    Abstract: A phase-change memory device according to the present invention includes a phase-change layer, a stacked heater electrode electrically connected to the phase-change layer, and a contact plug electrically connected to the stacked heater electrode. The stacked heater electrode includes at least a first electrode portion made of a first electrically conductive material and a second electrode portion provided in contact with the inner side of the first electrode portion. The second electrode portion is made of a second electrically conductive material having a resistivity lower than the resistivity of the first electrically conductive material.
    Type: Application
    Filed: September 18, 2007
    Publication date: March 20, 2008
    Applicant: Elpida Memory, Inc.
    Inventor: Tsutomu Hayakawa
  • Publication number: 20080061282
    Abstract: A phase change memory includes a sidewall insulation film and a heater electrode which are formed in a contact hole formed in an interlayer insulation film on a lower electrode. The heater electrode has a recessed structure. In a recessed area surrounded by the sidewall insulation film, the heater electrode and a phase change film are contacted with each other. A phase change region is formed only in an area contacted with the sidewall insulation film. The sidewall insulation film is an anti-oxidizing insulation film. The phase change region and the heater electrode which are heated to a high temperature upon rewriting are not contacted with the interlayer insulation film as an oxidizing insulation film.
    Type: Application
    Filed: September 4, 2007
    Publication date: March 13, 2008
    Applicant: ELPIDA MEMORY, INC.
    Inventors: Natsuki Sato, Tsutomu Hayakawa
  • Publication number: 20080048170
    Abstract: A semiconductor memory device comprises a heater electrode, a phase change portion, and an upper electrode. The phase change portion is connected to the heater electrode in a first direction. The upper electrode has an upper surface, a lower surface and a hole. The hole pierces the upper electrode between the upper and the lower surfaces in the first direction. The hole has an inner wall, which is connected to the phase change portion in a second direction perpendicular to the first direction.
    Type: Application
    Filed: July 19, 2007
    Publication date: February 28, 2008
    Applicant: ELPIDA MEMORY, INC.
    Inventor: Tsutomu Hayakawa
  • Publication number: 20080042118
    Abstract: A phase-change memory device has a different-material contact plug having a first electrically conductive material plug made of a first electrically conductive material, and a second electrically conductive material plug made of a second electrically conductive material having a specific resistance smaller than the first electrically conductive material, the first electrically conductive material plug and the second electrically conductive material plug being buried in a common contact hole. The different-material contact plug is effective for reducing the radiation of heat from a contact plug beneath a phase-change layer. The phase-change memory device also includes an extension electrode layer held in contact with a portion of the bottom surface of the phase-change layer in an area displaced off a position directly above a contact surface through which the phase-change layer and the heater electrode contact each other.
    Type: Application
    Filed: February 23, 2007
    Publication date: February 21, 2008
    Applicant: ELPIDA MEMORY, INC.
    Inventor: Tsutomu Hayakawa
  • Publication number: 20080006813
    Abstract: A semiconductor memory device comprises a heater electrode, a phase change portion, a heat insulation portion and an upper electrode. The phase change portion comprises a concave portion and a contact portion. The concave portion is in contact with the heater electrode. The contact portion is formed integrally with the concave portion. The heat insulation portion is formed in the concave portion. The upper electrode is formed on the contact portion and the heat insulation portion so that the heat insulation portion is positioned between the concave portion and the upper electrode.
    Type: Application
    Filed: June 21, 2007
    Publication date: January 10, 2008
    Inventor: Tsutomu Hayakawa
  • Publication number: 20070294923
    Abstract: The present invention provides footwear capable of alleviating the effects of sweating feet.
    Type: Application
    Filed: November 28, 2006
    Publication date: December 27, 2007
    Applicant: NIHON HEALTH SHOES CO., LTD.
    Inventor: Tsutomu Hayakawa
  • Publication number: 20070165452
    Abstract: A composite plug 104 is formed, and both a first plug (TiN) 106 and a second plug (W) 108 are disposed in one contact hole; the first plug (TiN) 106 functions as a heater electrode and the second plug (W) 108 functions as a contact plug. This eliminates the need to stack the heater electrode on the contact plug. The resistivities R11 and R12 of the first and second plugs of the composite plug 104 are in a relationship R11>R12.
    Type: Application
    Filed: January 16, 2007
    Publication date: July 19, 2007
    Applicant: ELPIDA MEMORY, INC.
    Inventor: Tsutomu Hayakawa
  • Publication number: 20070120107
    Abstract: A phase-change memory device has a phase-change layer, a heater electrode having an end held in contact with the phase-change layer, a contact plug of different kinds of material having a first electrically conductive material plug made of a first electrically conductive material and held in contact with the other end of the heater electrode, and a second electrically conductive material plug made of a second electrically conductive material having a specific resistance smaller than the first electrically conductive material, the first electrically conductive material plug and the second electrically conductive material plug being held in contact with each other through at least respective side surfaces thereof, the heater electrode and the second electrically conductive material plug being not in overlapping relation to each other, and an electrically conductive layer electrically connected to the second electrically conductive material plug.
    Type: Application
    Filed: November 27, 2006
    Publication date: May 31, 2007
    Inventor: Tsutomu HAYAKAWA
  • Publication number: 20070120106
    Abstract: A phase-change memory device has a phase-change layer, a heater electrode having an end held in contact with the phase-change layer, a contact plug of different kinds of material having a first electrically conductive material plug made of a first electrically conductive material and held in contact with the other end of the heater electrode, and a second electrically conductive material plug made of a second electrically conductive material having a specific resistance smaller than the first electrically conductive material, the first electrically conductive material plug and the second electrically conductive material plug being stacked in one contact hole, the heater electrode and the second electrically conductive material plug being held in contact with each other in overlapping relation to each other, and an electrically conductive layer electrically connected to the second electrically conductive material plug.
    Type: Application
    Filed: November 27, 2006
    Publication date: May 31, 2007
    Inventors: Tsutomu HAYAKAWA, Shinpei Iijima
  • Publication number: 20070069249
    Abstract: The invention provides a novel structure of a phase change memory device. In the phase change memory device of the invention, an electrode acting as a radiating fin does not exit immediately above a phase change area of a phase change layer (115). A heater electrode (111) and landing electrode layer (113a, 114a) both contact the bottom of the phase change layer (115) made of GST. The landing electrode layer (113a, 114a) contacts the bottom of the phase change layer (115) to partially overlap in a region off from a portion immediately above the contact face (Y) of the phase change layer and heater electrode. The contact electrode (116, 118) is directly connected to the landing electrode layer (113a, 114a) in a portion off from a portion immediately above the heater electrode (111). The phase change layer of GST or the like does not exist immediately below the contact electrode.
    Type: Application
    Filed: September 11, 2006
    Publication date: March 29, 2007
    Inventor: Tsutomu Hayakawa
  • Patent number: 6948319
    Abstract: A cogeneration system is provided which includes a prime mover for obtaining power for driving a generator by combustion of a fuel, a waste heat boiler for recovering thermal energy from exhaust gas discharged from the prime mover, and a heat exchanger for heating air that is to be fed into an air conditioner by heat exchange with the exhaust gas discharged from the waste heat boiler. Drain water that is generated from the exhaust gas cooled by heat exchange in the air-heating heat exchanger (5) with the air that is to be fed into the air conditioner (30) is recovered by drain water recovery/supply means (36). The drain water recovery/supply means (36) supplies the drain water thus recovered to appliances (37, 38) that require comparatively high temperature water. Thermal energy can thus be recovered effectively from the drain water discharged from the heat exchanger on the downstream side of the waste heat boiler, thereby improving the efficiency of recovery of waste heat energy.
    Type: Grant
    Filed: January 21, 2002
    Date of Patent: September 27, 2005
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Tsutomu Hayakawa, Keiichi Samekawa, Yasuhiro Kume, Yuuji Mukano
  • Patent number: 6861319
    Abstract: There is provided a method of fabricating a gate electrode, including the steps of (a) forming a gate oxide film at a surface of a semiconductor substrate, (b) forming a multi-layered structure on the gate oxide film, the multi-layered structure including a polysilicon layer formed on the gate oxide film, a refractive metal silicide layer formed on the polysilicon layer, and a silicon nitride layer formed on the refractive metal silicide layer, (c) thermally annealing the multi-layered structure in a nitrogen atmosphere to thereby form a silicon nitride film on sidewalls of the polysilicon layer and the refractive metal silicide layer, and (d) oxidizing the semiconductor substrate and the multi-layered structure.
    Type: Grant
    Filed: February 3, 2003
    Date of Patent: March 1, 2005
    Assignee: Elpida Memory, Inc.
    Inventors: Akira Hoshino, Kanta Saino, Shinichi Horiba, Tsutomu Hayakawa