Patents by Inventor Shinjiro Umehara

Shinjiro Umehara 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: 9711390
    Abstract: A method of forming a shallow trench isolation trench in a semiconductor substrate is described. The method includes forming a trench in a region of the substrate, forming a liner in the trench, wherein the liner includes a first dielectric material, adhering a halogen element to the liner, forming a second dielectric material in the trench, annealing the first dielectric material and the second dielectric material, exposing a portion of a surface of the second dielectric material, and isotropically etching the exposed portion of the surface of the second dielectric material to form an air gap in the shallow trench isolation trench.
    Type: Grant
    Filed: May 21, 2015
    Date of Patent: July 18, 2017
    Assignee: SanDisk Technologies LLC
    Inventors: Shinjiro Umehara, Daiki Teshima
  • Publication number: 20160343608
    Abstract: A method of forming a shallow trench isolation trench in a semiconductor substrate is described. The method includes forming a trench in a region of the substrate, forming a liner in the trench, wherein the liner includes a first dielectric material, adhering a halogen element to the liner, forming a second dielectric material in the trench, annealing the first dielectric material and the second dielectric material, exposing a portion of a surface of the second dielectric material, and isotropically etching the exposed portion of the surface of the second dielectric material to form an air gap in the shallow trench isolation trench.
    Type: Application
    Filed: May 21, 2015
    Publication date: November 24, 2016
    Applicant: SANDISK TECHNOLOGIES INC.
    Inventors: Shinjiro Umehara, Daiki Teshima
  • Patent number: 8194362
    Abstract: A magnetoresistive effect device includes an underlayer, an antiferromagnetic layer, a first ferromagnetic layer, a nonmagnetic layer, and a second ferromagnetic layer which are multilayered in this order on a substrate. The underlayer is formed of a metal nitride, and the antiferromagnetic layer is formed of an antiferromagnetic material including Ir and Mn.
    Type: Grant
    Filed: July 23, 2010
    Date of Patent: June 5, 2012
    Assignee: Fujitsu Limited
    Inventors: Takahiro Ibusuki, Masashige Sato, Shinjiro Umehara
  • Patent number: 8184407
    Abstract: An underlying layer (2) made of NiFeN is disposed over the principal surface of a substrate. A pinning layer (3) made of antiferromagnetic material containing Ir and Mn is disposed on the underlying layer. A reference layer (4c) made of ferromagnetic material whose magnetization direction is fixed through exchange-coupling with the pinning layer directly or via another ferromagnetic material layer, is disposed over the pinning layer. A nonmagnetic layer (7) made of nonmagnetic material is disposed over the reference layer. A free layer (8) made of ferromagnetic material whose magnetization direction changes in dependence upon an external magnetic field, is disposed over the nonmagnetic layer.
    Type: Grant
    Filed: March 3, 2008
    Date of Patent: May 22, 2012
    Assignee: Fujitsu Limited
    Inventors: Takahiro Ibusuki, Masashige Sato, Shinjiro Umehara
  • Patent number: 8081404
    Abstract: A magnetoresistive element includes: a free layer made of a ferromagnetic material, the free layer configured to change the direction of magnetization under the influence of an external magnetic field; an insulating layer overlaid on the free layer, the insulating layer made of an insulating material; an amorphous reference layer overlaid on the insulating layer, the amorphous reference layer made of a ferromagnetic material, the amorphous reference layer configured to fix the magnetization in a predetermined direction; a crystal layer overlaid on the amorphous reference layer, the crystal layer containing crystal grains; a non-magnetic layer overlaid on the crystal layer, the non-magnetic layer containing crystal grains having grown from the crystal grains in the crystal layer; and a pinned layer overlaid on the non-magnetic layer, the pinned layer configured to fix the magnetization in a predetermined direction.
    Type: Grant
    Filed: August 27, 2009
    Date of Patent: December 20, 2011
    Assignee: Fujitsu Limited
    Inventors: Takahiro Ibusuki, Shinjiro Umehara, Masashige Sato
  • Patent number: 8072714
    Abstract: A barrier layer is disposed over a pinned layer made of ferromagnetic material having a fixed magnetization direction, the barrier layer having a thickness allowing electrons to transmit therethrough by a tunneling phenomenon. A first free layer is disposed over the barrier layer, the first free layer being made of amorphous or fine crystalline soft magnetic material which changes a magnetization direction under an external magnetic field. A second free layer is disposed over the first free layer, the second free layer being made of crystalline soft magnetic material which changes a magnetization direction under an external magnetic field and being exchange-coupled to the first free layer. A tunneling magnetoresistance device is provided which has good magnetic characteristics and can suppress a tunnel resistance change rate from being lowered.
    Type: Grant
    Filed: March 11, 2011
    Date of Patent: December 6, 2011
    Assignee: Fujitsu Limited
    Inventors: Masashige Sato, Shinjiro Umehara, Takahiro Ibusuki
  • Publication number: 20110164448
    Abstract: A barrier layer is disposed over a pinned layer made of ferromagnetic material having a fixed magnetization direction, the barrier layer having a thickness allowing electrons to transmit therethrough by a tunneling phenomenon. A first free layer is disposed over the barrier layer, the first free layer being made of amorphous or fine crystalline soft magnetic material which changes a magnetization direction under an external magnetic field. A second free layer is disposed over the first free layer, the second free layer being made of crystalline soft magnetic material which changes a magnetization direction under an external magnetic field and being exchange-coupled to the first free layer. A tunneling magnetoresistance device is provided which has good magnetic characteristics and can suppress a tunnel resistance change rate from being lowered.
    Type: Application
    Filed: March 11, 2011
    Publication date: July 7, 2011
    Applicant: Fujitsu Limited
    Inventors: Masashige Sato, Shinjiro Umehara, Takahiro Ibusuki
  • Publication number: 20100284103
    Abstract: A magnetoresistive effect device includes an underlayer, an antiferromagnetic layer, a first ferromagnetic layer, a nonmagnetic layer, and a second ferromagnetic layer which are multilayered in this order on a substrate. The underlayer is formed of a metal nitride, and the antiferromagnetic layer is formed of an antiferromagnetic material including Ir and Mn.
    Type: Application
    Filed: July 23, 2010
    Publication date: November 11, 2010
    Applicant: FUJITSU LIMITED
    Inventors: Takahiro Ibusuki, Masashige Sato, Shinjiro Umehara
  • Publication number: 20100053824
    Abstract: A magnetoresistive element includes: a free layer made of a ferromagnetic material, the free layer configured to change the direction of magnetization under the influence of an external magnetic field; an insulating layer overlaid on the free layer, the insulating layer made of an insulating material; an amorphous reference layer overlaid on the insulating layer, the amorphous reference layer made of a ferromagnetic material, the amorphous reference layer configured to fix the magnetization in a predetermined direction; a crystal layer overlaid on the amorphous reference layer, the crystal layer containing crystal grains; a non-magnetic layer overlaid on the crystal layer, the non-magnetic layer containing crystal grains having grown from the crystal grains in the crystal layer; and a pinned layer overlaid on the non-magnetic layer, the pinned layer configured to fix the magnetization in a predetermined direction.
    Type: Application
    Filed: August 27, 2009
    Publication date: March 4, 2010
    Applicant: FUJITSU LIMITED
    Inventors: Takahiro Ibusuki, Shinjiro Umehara, Masashige Sato
  • Publication number: 20090244790
    Abstract: An magnetoresistive element includes: an underlayer made of a nitride; a pinning layer made of an antiferromagnetic layer overlaid on the underlayer, the pinning layer having the close-packed surface in the (111) surface of crystal, the pinning layer setting the (002) surface of crystal in parallel with the surface of the underlayer; a reference layer overlaid on the pinning layer, the reference layer having the magnetization fixed in a predetermined direction based on the exchange coupling with the pinning layer; a nonmagnetic layer overlaid on the reference layer, the nonmagnetic layer made of a nonmagnetic material; and a free layer overlaid on the nonmagnetic layer, the free layer made of a ferromagnetic material, the free layer enabling a change in the direction of the magnetization under the influence of an external magnetic field.
    Type: Application
    Filed: March 23, 2009
    Publication date: October 1, 2009
    Applicant: FUJITSU LIMITED
    Inventors: Takahiro Ibusuki, Masashige Sato, Shinjiro Umehara
  • Patent number: 7535755
    Abstract: The magnetic memory device includes a magnetic shield film 48, and a magnetoresistive effect element 62 formed over the magnetic shield film 48 and including a magnetic layer 52, a non-magnetic layer 54 and a magnetic layer 56, in which a magnetization direction of the first magnetic layer or the second magnetic layer is reversed by spin injection, and a second magnetic shield film 68 formed over the side wall of the magnetoresistive effect element 62. Thus, the arrival of the leakage magnetic field from the interconnection near the magnetoresistive effect element 62 can be effectively prevented.
    Type: Grant
    Filed: September 28, 2006
    Date of Patent: May 19, 2009
    Assignee: Fujitsu Limited
    Inventors: Shinjiro Umehara, Hiroshi Ashida, Takao Ochiai, Masashige Sato, Kazuo Kobayashi
  • Publication number: 20090097170
    Abstract: A ferromagnetic tunnel junction element is a magnetoresistance effect element wherein an electric resistance varies in accordance with a magnetic field applied. The ferromagnetic tunnel junction element includes a pinned layer wherein at least a part of a magnetization direction is held, and an insulation layer formed on the pinned layer, creating an energy barrier that electrons can flow through by a tunnel effect. A first free layer made of a first ferromagnetic material containing boron atoms, is formed on the insulation layer. In the first free layer, a direction of the magnetization switches under an influence of an external magnetic field. A second free layer made of a first ferromagnetic material containing boron atoms, is formed on the first free layer. The direction of magnetization of the second free layer switches under the influence of the external magnetic field, exchanging and coupling with the first free layer.
    Type: Application
    Filed: September 2, 2008
    Publication date: April 16, 2009
    Applicant: FUJITSU LIMITED
    Inventors: Masashige Sato, Shinjiro Umehara, Takahiro Ibusuki
  • Patent number: 7466526
    Abstract: A ferromagnetic tunnel junction is disclosed. The ferromagnetic tunnel junction includes a pinned magnetic layer, a tunnel insulating film formed on the pinned magnetic layer, and a free magnetic multilayer body formed on the tunnel insulating film. The free magnetic multilayer body includes a first free magnetic layer, a diffusion barrier layer, and a second free magnetic layer stacked in this order on the tunnel insulating film. The first free magnetic layer and the second free magnetic layer are ferromagnetically coupled with each other. The diffusion barrier layer inhibits the additive element contained in the first free magnetic layer from diffusing into the second free magnetic layer.
    Type: Grant
    Filed: October 25, 2005
    Date of Patent: December 16, 2008
    Assignee: Fujitsu Limited
    Inventors: Masashige Sato, Shinjiro Umehara, Hiroshi Ashida, Kazuo Kobayashi
  • Publication number: 20080232003
    Abstract: An underlying layer (2) made of NiFeN is disposed over the principal surface of a substrate. A pinning layer (3) made of antiferromagnetic material containing Ir and Mn is disposed on the underlying layer. A reference layer (4c) made of ferromagnetic material whose magnetization direction is fixed through exchange-coupling with the pinning layer directly or via another ferromagnetic material layer, is disposed over the pinning layer. A nonmagnetic layer (7) made of nonmagnetic material is disposed over the reference layer. A free layer (8) made of ferromagnetic material whose magnetization direction changes in dependence upon an external magnetic field, is disposed over the nonmagnetic layer.
    Type: Application
    Filed: March 3, 2008
    Publication date: September 25, 2008
    Applicant: FUJITSU LIMITED
    Inventors: Takahiro IBUSUKI, Masashige SATO, Shinjiro UMEHARA
  • Patent number: 7382643
    Abstract: The magnetoresistive effect element comprises a pinned magnetic layer 16 having a multilayered synthetic antiferromagnet (SAF) structure, a nonmagnetic spacer layer 18 formed on the pinned magnetic layer 16, a free magnetic layer 20 formed on the nonmagnetic spacer layer 18 and formed of a single ferromagnetic layer, a nonmagnetic spacer layer 22 formed on the free magnetic layer 20, and a pinned magnetic layer 24 of a multilayered SAF structure formed on the nonmagnetic spacer layer 22, wherein a magnetization direction of the ferromagnetic layer 16c of the pinned magnetic layer 16, which is nearest the free magnetic layer 20, and a magnetization direction of the ferromagnetic layer 24a of the pinned magnetic layer 24, which is nearest the free magnetic layer 20, are opposite to each other.
    Type: Grant
    Filed: January 25, 2006
    Date of Patent: June 3, 2008
    Assignee: Fujitsu Limited
    Inventors: Hiroshi Ashida, Masashige Sato, Shinjiro Umehara, Kazuo Kobayashi
  • Publication number: 20080112093
    Abstract: A barrier layer is disposed over a pinned layer made of ferromagnetic material having a fixed magnetization direction, the barrier layer having a thickness allowing electrons to transmit therethrough by a tunneling phenomenon. A first free layer is disposed over the barrier layer, the first free layer being made of amorphous or fine crystalline soft magnetic material which changes a magnetization direction under an external magnetic field. A second free layer is disposed over the first free layer, the second free layer being made of crystalline soft magnetic material which changes a magnetization direction under an external magnetic field and being exchange-coupled to the first free layer. A tunneling magnetoresistance device is provided which has good magnetic characteristics and can suppress a tunnel resistance change rate from being lowered.
    Type: Application
    Filed: September 6, 2007
    Publication date: May 15, 2008
    Applicant: Fujitsu Limited
    Inventors: Masashige Sato, Shinjiro Umehara, Takahiro Ibusuki
  • Publication number: 20080080102
    Abstract: A TMR element is provided which has a large MR ratio. The TMR element has a tunnel barrier layer formed between a magnetization fixed layer and a magnetization free layer, and a cap layer disposed on the magnetization free layer. The tunnel barrier layer is formed of an MgO film. The magnetization free layer is formed of a CoFeB film. The cap layer is formed by forming a Ti film immediately above the CoFeB film such that the Ti film is in contact with the CoFeB film. This makes it possible to largely enhance the MR ratio of the TMR element. Further, by using the TMR element for a magnetic head and an MRAM, it is possible to improve the performance of magnetic heads and MRAMs.
    Type: Application
    Filed: September 26, 2007
    Publication date: April 3, 2008
    Applicant: FUJITSU LIMITED
    Inventors: Takahiro Ibusuki, Masashige Sato, Shinjiro Umehara
  • Publication number: 20070278603
    Abstract: The magnetic memory device comprises a recording layer 70 formed linearly over a substrate 10 and having a plurality of pinning sites 52 for restricting the motion of domain walls 50 formed at a prescribed pitch and having the regions between the plural pinning sites 52 as recording bits 72. The recording layer 70 includes a first recording layer portion 46 and a second recording layer portion 68, and the second recording layer portion 68 is positioned above the first recording layer portion 46 and has one end connected to one end of the first recording layer portion 46. The second recording layer portion 68 is formed above the first recording layer portion 46, and the end of the second recording layer portion 68 is connected to one end of the first recording layer portion 46, whereby the space required to form the recording layer 70 can be small.
    Type: Application
    Filed: December 5, 2006
    Publication date: December 6, 2007
    Applicant: FUJITSU LIMITED
    Inventors: Takao Ochiai, Shinjiro Umehara, Hiroshi Ashida, Masashige Sato, Yutaka Shimizu
  • Publication number: 20070277910
    Abstract: An electrode, an antiferromagnetic film, a ferromagnetic film, a nonmagnetic film, a ferromagnetic film, a tunnel insulating film, a ferromagnetic film, a first Ta film, a Ru film, and a second Ta film are formed in sequence on a substrate. The thickness of the second Ta film is about 0.5 nm. The second Ta film is naturally oxidized after being formed. Then, heat treatment to improve the characteristic of a TMR film is performed. The temperature of this heat treatment is approximately from 200° C. to 300° C. In a conventional manufacturing method, film peeling occurs in this heat treatment, and accompanying this, defects such as occurrence of holes and wrinkles further occur, but in the present method, such an occurrence of defects is prevented since the Ta film is formed at the uppermost surface. Subsequently, the Ta film and so on are patterned.
    Type: Application
    Filed: November 30, 2006
    Publication date: December 6, 2007
    Applicant: FUJITSU LIMITED
    Inventors: Takao Ochiai, Shinjiro Umehara, Hiroshi Ashida, Masashige Sato, Kazuo Kobayashi
  • Publication number: 20070242505
    Abstract: The magnetic memory device comprises a magnetoresistive effect element 54 including a magnetic layer 42 having a magnetization direction pinned in a first direction, a non-magnetic layer 50 formed on the magnetic layer 42, and a magnetic layer 52 formed on the non-magnetic layer 50 and having a first magnetic domain magnetized in a first direction and a second magnetic domain magnetized in a second direction opposite to the first direction; and a write current applying circuit for flowing a write current in the second magnetic layer 52 in the first direction or the second direction to shift a magnetic domain wall between the first magnetic domain and the second magnetic domain to control a magnetization direction of a part of the magnetic layer 52, opposed to the magnetic layer 42.
    Type: Application
    Filed: June 5, 2006
    Publication date: October 18, 2007
    Applicant: FUJITSU LIMITED
    Inventors: Takao Ochiai, Shinjiro Umehara, Hiroshi Ashida, Masashige Sato, Kazuo Kobayashi