Patents by Inventor Kazunari Kurita

Kazunari Kurita 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: 9496139
    Abstract: The present invention provides a method of more efficiently producing a semiconductor epitaxial wafer, which can suppress metal contamination by achieving higher gettering capability. A method of producing a semiconductor epitaxial wafer 100 according to the present invention includes a first step of irradiating a semiconductor wafer 10 with cluster ions 16 to form a modifying layer 18 formed from a constituent element of the cluster ions 16 in a surface portion 10A of the semiconductor wafer; and a second step of forming an epitaxial layer 20 on the modifying layer 18 of the semiconductor wafer 10.
    Type: Grant
    Filed: March 19, 2012
    Date of Patent: November 15, 2016
    Assignee: SUMCO Corporation
    Inventors: Takeshi Kadono, Kazunari Kurita
  • Publication number: 20160181311
    Abstract: The present invention provides a method of producing a semiconductor epitaxial wafer, which can suppress metal contamination by achieving higher gettering capability. The method of producing a semiconductor epitaxial wafer includes a first step of irradiating a surface portion 10A of a semiconductor wafer 10 with cluster ions 16 thereby forming a modifying layer 18 formed from carbon and a dopant element contained as a solid solution that are constituent elements of the cluster ions 16, in the surface portion 10A of the semiconductor wafer; and a second step of forming an epitaxial layer 20 on the modifying layer 18 of the semiconductor wafer, the epitaxial layer 20 having a dopant element concentration lower than the peak concentration of the dopant element in the modifying layer 18.
    Type: Application
    Filed: November 11, 2013
    Publication date: June 23, 2016
    Applicant: SUMCO CORPORATION
    Inventors: Takeshi Kadono, Kazunari Kurita
  • Publication number: 20160181312
    Abstract: An object is to provide a method of producing a semiconductor epitaxial wafer having higher gettering capability and a reduced haze level of the surface of a semiconductor epitaxial layer. The method of producing a semiconductor epitaxial wafer, according to the present invention includes: a first step of irradiating a semiconductor wafer 10 with cluster ions 16 thereby forming a modifying layer 18 formed from a constituent element of the cluster ions 16 contained as a solid solution, in a surface portion 10A of the semiconductor wafer; a second step of performing heat treatment for crystallinity recovery on the semiconductor wafer 10 after the first step such that the haze level of the semiconductor wafer surface portion 10A is 0.20 ppm or less; and a third step of forming an epitaxial layer 20 on the modifying layer 18 of the semiconductor wafer after the second step.
    Type: Application
    Filed: November 12, 2013
    Publication date: June 23, 2016
    Applicant: SUMCO CORPORATION
    Inventors: Takeshi Kadono, Kazunari Kurita
  • Publication number: 20160181313
    Abstract: Provided is a semiconductor epitaxial wafer having metal contamination reduced by achieving higher gettering capability, a method of producing the semiconductor epitaxial wafer, and a method of producing a solid-state image sensing device using the semiconductor epitaxial wafer. The method of producing a semiconductor epitaxial wafer 100 includes a first step of irradiating a semiconductor wafer 10 containing at least one of carbon and nitrogen with cluster ions 16 thereby forming a modifying layer 18 formed from a constituent element of the cluster ions 16 contained as a solid solution, in a surface portion of the semiconductor wafer 10; and a second step of forming a first epitaxial layer 20 on the modifying layer 18 of the semiconductor wafer 10.
    Type: Application
    Filed: November 11, 2013
    Publication date: June 23, 2016
    Applicant: SUMCO CORPORATION
    Inventors: Takeshi Kadono, Kazunari Kurita
  • Patent number: 9281197
    Abstract: A semiconductor wafer is set in a laser irradiation apparatus, and laser beam irradiation is performed while the semiconductor wafer is moved. At this time, a laser beam emitted from a laser generating apparatus is condensed by a condensing lens so that the condensing point (focal point) is positioned at a depth of several tens of?m or so from one surface of the semiconductor wafer. Thereby, the crystal structure of the semiconductor wafer in the position having such a depth is modified, and a gettering sink is formed.
    Type: Grant
    Filed: October 16, 2009
    Date of Patent: March 8, 2016
    Assignee: SUMCO CORPORATION
    Inventor: Kazunari Kurita
  • Patent number: 8864907
    Abstract: A condition of a single crystal manufacturing step subjected to the Czochralski method applying an initial oxygen concentration, a dopant concentration or resistivity, and a heat treatment condition is determined simply and clearly on the basis of the conditions of a wafer manufacturing step and a device step so as to obtain a silicon wafer having a desired gettering capability. A manufacturing method of a silicon substrate which is manufactured from a silicon single crystal grown by the CZ method and provided for manufacturing a solid-state imaging device is provided. The internal state of the silicon substrate, which depends on the initial oxygen concentration, the carbon concentration, the resistivity, and the pulling condition of the silicon substrate, is determined by comparing a white spot condition representing upper and lower limits of the density of white spots as device characteristics with the measured density of white spots.
    Type: Grant
    Filed: March 4, 2009
    Date of Patent: October 21, 2014
    Assignee: Sumco Corporation
    Inventors: Kazunari Kurita, Shuichi Omote
  • Publication number: 20140080247
    Abstract: The present invention provides a method of more efficiently producing a semiconductor epitaxial wafer, which can suppress metal contamination by achieving higher gettering capability. A method of producing a semiconductor epitaxial wafer 100 according to the present invention includes a first step of irradiating a semiconductor wafer 10 with cluster ions 16 to form a modifying layer 18 formed from a constituent element of the cluster ions 16 in a surface portion 10A of the semiconductor wafer; and a second step of forming an epitaxial layer 20 on the modifying layer 18 of the semiconductor wafer 10.
    Type: Application
    Filed: March 19, 2012
    Publication date: March 20, 2014
    Applicant: SUMCO CORPORATION
    Inventors: Takeshi Kadono, Kazunari Kurita
  • Patent number: 8658516
    Abstract: An object of the present invention is to provide a method of producing a silicon wafer and a method of producing an epitaxial wafer, which enable easily forming a gettering site in a relatively short period of time and effectively suppressing occurrence of dislocation induced by internal stresses. Specifically, the present invention provides a method of producing a silicon wafer, comprising: irradiating a first laser beam having a relatively long wavelength and a second laser beam having a relatively short wavelength onto a portion of a silicon wafer located at a predetermined depth measured from a surface of the silicon wafer, wherein the first laser beam is concentrated at a portion located at a predetermined depth of the wafer to form a process-affected layer for gettering heavy metals thereat, the second laser beam is concentrated at a beam-concentration portion in the vicinity of the surface of the wafer to melt the beam-concentration portion, the beam-concentration portion is then recrystallized.
    Type: Grant
    Filed: January 28, 2011
    Date of Patent: February 25, 2014
    Assignee: Sumco Corporation
    Inventor: Kazunari Kurita
  • Patent number: 8629044
    Abstract: An object of the present invention is to provide a method of producing a silicon wafer and a method of producing an epitaxial wafer, which enable easily forming a gettering site in a relatively short period of time and effectively suppressing occurrence of dislocation induced by internal stresses. Specifically, the present invention provides a method of producing a silicon wafer, comprising: irradiating a first laser beam having a relatively long wavelength and a second laser beam having a relatively short wavelength onto a portion of a silicon wafer located at a predetermined depth measured from a surface of the silicon wafer, wherein the first laser beam is concentrated at a portion located at a predetermined depth of the wafer to form a process-affected layer for gettering heavy metals thereat, the second laser beam is concentrated at a beam-concentration portion in the vicinity of the surface of the wafer to melt the beam-concentration portion, the beam-concentration portion is then recrystallized.
    Type: Grant
    Filed: January 28, 2011
    Date of Patent: January 14, 2014
    Assignee: Sumco Corporation
    Inventor: Kazunari Kurita
  • Patent number: 8492193
    Abstract: There is provided a semiconductor substrate for solid-state image sensing device in which the production cost is lower than that of a gettering method through a carbon ion implantation and problems such as occurrence of particles at a device production step and the like are solved. Silicon substrate contains solid-soluted carbon having a concentration of 1×1016-1×1017 atoms/cm3 and solid-soluted oxygen having a concentration of 1.4×1018-1.6×1018 atoms/cm3.
    Type: Grant
    Filed: October 4, 2011
    Date of Patent: July 23, 2013
    Assignee: Sumco Corporation
    Inventor: Kazunari Kurita
  • Patent number: 8357592
    Abstract: A method for manufacturing a semiconductor substrate dedicated to a semiconductor device, in which multi-photon absorption is generated in a micro-region inside the semiconductor substrate by condensing laser beams in any micro-region inside the semiconductor substrate, and a gettering sink is formed by changing the crystal structure of only the micro-region.
    Type: Grant
    Filed: May 26, 2010
    Date of Patent: January 22, 2013
    Assignee: Sumco Corporation
    Inventor: Kazunari Kurita
  • Publication number: 20120329204
    Abstract: A wafer for backside illumination type solid imaging device has a plurality of pixels inclusive of a photoelectric conversion device and a charge transfer transistor at its front surface side and a light receiving surface at its back surface side, wherein said wafer is a SOI wafer obtained by forming a given active layer on a support substrate made of C-containing p-type semiconductor material through an insulating layer.
    Type: Application
    Filed: August 13, 2012
    Publication date: December 27, 2012
    Applicant: Sumco Corporation
    Inventors: Kazunari Kurita, Shuichi Omote
  • Patent number: 8309436
    Abstract: A method of producing an epitaxial substrate for a solid-state imaging device, comprising: forming a gettering sink by injecting laser beam to a semiconductor substrate through one surface thereof, condensing the laser beam to an arbitrarily selected portion of the semiconductor substrate, thereby causing multi-photon absorption process to occur in the portion, and forming a gettering sink having a modified crystal structure; and epitaxially growing at least two epitaxial layers on the semiconductor substrate in which the gettering sink is formed.
    Type: Grant
    Filed: May 28, 2010
    Date of Patent: November 13, 2012
    Assignee: Sumco Corporation
    Inventor: Kazunari Kurita
  • Patent number: 8263484
    Abstract: This method for manufacturing a high resistivity silicon wafer includes pulling a single crystal such that the single crystal has a p-type dopant concentration at which a wafer surface resistivity becomes in a range of 0.1 to 10 k ?cm, an oxygen concentration Oi of 5.0×1017 to 20×1017 atoms/cm3 (ASTM F-121, 1979), and a nitrogen concentration of 1.0×1013 to 10×1013 atoms/cm3 (ASTM F-121, 1979) by using a Czochralski method, processing the single crystal into wafers by slicing the single crystal, and subjecting the wafer to an oxygen out-diffusion heat treatment process in a non-oxidizing atmosphere.
    Type: Grant
    Filed: March 1, 2010
    Date of Patent: September 11, 2012
    Assignee: Sumco Corporation
    Inventor: Kazunari Kurita
  • Patent number: 8124501
    Abstract: A semiconductor wafer is produced by irradiating a laser beam to either face of a semiconductor wafer so as to fit a focusing position into a given depth position of the semiconductor wafer to generate a multiphoton absorption process only in a specific portion of the semiconductor wafer at the given depth position to thereby form a gettering sink.
    Type: Grant
    Filed: May 6, 2009
    Date of Patent: February 28, 2012
    Assignee: SUMCO Corporation
    Inventor: Kazunari Kurita
  • Publication number: 20120021558
    Abstract: There is provided a semiconductor substrate for solid-state image sensing device in which the production cost is lower than that of a gettering method through a carbon ion implantation and problems such as occurrence of particles at a device production step and the like are solved. Silicon substrate contains solid-soluted carbon having a concentration of 1×1016-1×1017 atoms/cm3 and solid-soluted oxygen having a concentration of 1.4×1018-1.6×1018 atoms/cm3.
    Type: Application
    Filed: October 4, 2011
    Publication date: January 26, 2012
    Applicant: SUMCO CORPORATION
    Inventor: Kazunari KURITA
  • Patent number: 8101508
    Abstract: A silicon substrate is manufactured from a single crystal silicon that is doped with phosphorus (P) and is grown by a CZ method to have a predetermined carbon concentration and a predetermined initial oxygen concentration. An n+ epitaxial layer or an n+ implantation layer that is doped with phosphorus (P) at a predetermined concentration or more is formed on the silicon substrate. An n epitaxial layer that is doped with phosphorus (P) at a predetermined concentration is formed on the n+ layer.
    Type: Grant
    Filed: March 3, 2009
    Date of Patent: January 24, 2012
    Assignee: Sumco Corporation
    Inventors: Kazunari Kurita, Shuichi Omote
  • Publication number: 20110300371
    Abstract: [Problem] An object of the present invention is to provide an epitaxial substrate and a method for producing the same capable of suppressing metal contamination and thereby reducing occurrence of white defects of a solid state imaging sensor by maintaining sufficient gettering capability during a device manufacturing process. [Solving Means] The present invention is a method of producing an epitaxial substrate, comprising a step of growing an epitaxial layer on a silicon substrate containing carbon as a dopant to form an epitaxial substrate; and, after the formation of the epitaxial substrate, a step of applying a first thermal treatment and a second thermal treatment to the epitaxial substrate such that a density of oxygen precipitates in a surface layer of the silicon substrate constituting the epitaxial substrate is larger than a density of oxygen precipitates at a center of the silicon substrate in a thickness direction.
    Type: Application
    Filed: May 2, 2011
    Publication date: December 8, 2011
    Inventors: Shuichi Omote, Kazunari Kurita
  • Patent number: 8063466
    Abstract: There is provided a semiconductor substrate for solid-state image sensing device in which the production cost is lower than that of a gettering method through a carbon ion implantation and problems such as occurrence of particles at a device production step and the like are solved. Silicon substrate contains solid-soluted carbon having a concentration of 1×1016-1×1017 atoms/cm3 and solid-soluted oxygen having a concentration of 1.4×1018-1.6×1018 atoms/cm3.
    Type: Grant
    Filed: September 7, 2007
    Date of Patent: November 22, 2011
    Assignee: Sumco Corporation
    Inventor: Kazunari Kurita
  • Publication number: 20110248372
    Abstract: A semiconductor wafer is set in a laser irradiation apparatus, and laser beam irradiation is performed while the semiconductor wafer is moved. At this time, a laser beam emitted from a laser generating apparatus is condensed by a condensing lens so that the condensing point (focal point) is positioned at a depth of several tens of gm or so from one surface of the semiconductor wafer. Thereby, the crystal structure of the semiconductor wafer in the position having such a depth is modified, and a gettering sink is formed.
    Type: Application
    Filed: October 16, 2009
    Publication date: October 13, 2011
    Applicant: SUMCO CORPORATION
    Inventor: Kazunari Kurita