Patents by Inventor Toshiaki Saishoji

Toshiaki Saishoji 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: 7727334
    Abstract: In a Czochralski (CZ) single crystal puller equipped with a cooler and a thermal insulation member, which are to be disposed in a CZ furnace, smooth recharge and additional charge of material are made possible. Further, elimination of dislocations from a silicon seed crystal by use of the Dash's neck method can be performed smoothly. To these ends, there is provided a CZ single crystal puller, wherein a cooler and a thermal insulation member are immediately moved upward away from a melt surface during recharge or additional charge of material or during elimination of dislocations from a silicon seed crystal by use of the Dash's neck method.
    Type: Grant
    Filed: May 31, 2007
    Date of Patent: June 1, 2010
    Assignee: Sumco Techxiv Corporation
    Inventors: Hiroshi Inagaki, Shigeki Kawashima, Makoto Kamogawa, Toshirou Kotooka, Toshiaki Saishoji, Daisuke Ebi, Kentaro Nakamura, Kengo Hayashi, Yoshinobu Hiraishi, Shigeo Morimoto, Hiroshi Monden, Tadayuki Hanamoto, Tadashi Hata
  • Publication number: 20090173272
    Abstract: In a Czochralski (CZ) single crystal puller equipped with a cooler and a thermal insulation member, which are to be disposed in a CZ furnace, smooth recharge and additional charge of material are made possible. Further, elimination of dislocations from a silicon seed crystal by use of the Dash's neck method can be performed smoothly. To these ends, there is provided a CZ single crystal puller, wherein a cooler and a thermal insulation member are immediately moved upward away from a melt surface during recharge or additional charge of material or during elimination of dislocations from a silicon seed crystal by use of the Dash's neck method.
    Type: Application
    Filed: December 23, 2008
    Publication date: July 9, 2009
    Applicant: KOMATSU DENSHI KINOZOKU KABUSHIKI KAISHA
    Inventors: Hiroshi Inagaki, Shigeki Kawashima, Makoto Kamogawa, Toshirou Kotooka, Toshiaki Saishoji, Daisuke Ebi, Kentaro Nakamura, Kengo Hayashi, Yoshinobu Hiraishi, Shigeo Morimoto, Hiroshi Monden, Tadayuki Hanamoto, Tadashi Hata
  • Publication number: 20080311019
    Abstract: In a Czochralski (CZ) single crystal puller equipped with a cooler and a thermal insulation member, which are to be disposed in a CZ furnace, smooth recharge and additional charge of material are made possible. Further, elimination of dislocations from a silicon seed crystal by use of the Dash's neck method can be performed smoothly. To these ends, there is provided a CZ single crystal puller, wherein a cooler and a thermal insulation member are immediately moved upward away from a melt surface during recharge or additional charge of material or during elimination of dislocations from a silicon seed crystal by use of the Dash's neck method.
    Type: Application
    Filed: October 31, 2007
    Publication date: December 18, 2008
    Applicant: Komatsu Denshi Kinzoku Kabushiki Kaisha
    Inventors: Hiroshi Inagaki, Shigeki Kawashima, Makoto Kamogawa, Toshirou Kotooka, Toshiaki Saishoji, Daisuke Ebi, Kentaro Nakamura, Kengo Hayashi, Yoshinobu Hiraishi, Shigeo Morimoto, Hiroshi Monden, Tadayuki Hanamoto, Tadashi Hata
  • Publication number: 20080311021
    Abstract: In a Czochralski (CZ) single crystal puller equipped with a cooler and a thermal insulation member, which are to be disposed in a CZ furnace, smooth recharge and additional charge of material are made possible. Further, elimination of dislocations from a silicon seed crystal by use of the Dash's neck method can be performed smoothly. To these ends, there is provided a CZ single crystal puller, wherein a cooler and a thermal insulation member are immediately moved upward away from a melt surface during recharge or additional charge of material or during elimination of dislocations from a silicon seed crystal by use of the Dash's neck method.
    Type: Application
    Filed: October 31, 2007
    Publication date: December 18, 2008
    Applicant: Komatsu Denshi Kinzoku Kabushiki Kaisha
    Inventors: Hiroshi Inagaki, Shigeki Kawashima, Makoto Kamogawa, Toshirou Kotooka, Toshiaki Saishoji, Daisuke Ebi, Kentaro Nakamura, Kengo Hayashi, Yoshinobu Hiraishi, Shigeo Morimoto, Hiroshi Monden, Tadayuki Hanamoto, Tadashi Hata
  • Publication number: 20080302295
    Abstract: In the crystal growth rate (V), there is such a permissible range that the given quality of silicon single crystal can be maintained. This permissible range is determined in advance. The log data of crystal growth rate (V) is measured in the pulling up of silicon single crystal, and using the log data, the actual value of crystal growth rate (V) is determined. The actual value is compared with the permissible range. Any region of silicon single crystal corresponding to crystal growth rate (V) falling within the permissible range is judged as being a conforming region satisfying given standards, while any region of silicon single crystal corresponding to crystal growth rate (V) falling outside the permissible range is judged as being a defective region not satisfying given standards.
    Type: Application
    Filed: August 1, 2005
    Publication date: December 11, 2008
    Inventors: Toshirou Kotooka, Shin Matsukuma, Toshiaki Saishoji
  • Publication number: 20080115720
    Abstract: A semiconductor single crystal manufacturing apparatus and method are provided which are capable of improving the speed of designing and arranging a silicon single crystal manufacturing apparatus while reducing labor by making it possible to instantaneously find optimum design values and optimum arrangement for a cooler without requiring a lot of labor or time, regardless of a housing structure of a CZ furnace, in-furnace members' configuration, and manufacturing conditions. Stable manufacture of defect-free silicon single crystals is also made possible by designing and arranging the cooler such that when a heat absorption amount of the cooler is denoted by Q and a semiconductor single crystal radius is denoted by r, the heat absorption amount of the cooler Q satisfies r2/1100?Q?r2/400, or alternatively Q satisfies r2.7/20500?Q?r2.7/19300.
    Type: Application
    Filed: November 7, 2007
    Publication date: May 22, 2008
    Applicant: SUMCO TECHXIV KABUSHIKI KAISHA
    Inventors: Toshiaki Saishoji, Koichi Shimomura, Ryouta Suewaka, Daisuke Ebi
  • Publication number: 20070256625
    Abstract: In a Czochralski (CZ) single crystal puller equipped with a cooler and a thermal insulation member, which are to be disposed in a CZ furnace, smooth recharge and additional charge of material are made possible. Further, elimination of dislocations from a silicon seed crystal by use of the Dash's neck method can be performed smoothly. To these ends,there is provided a CZ single crystal puller, wherein a cooler and a thermal insulation member are immediately moved upward away from a melt surface during recharge or additional charge of material or during elimination of dislocations from a silicon seed crystal by use of the Dash's neck method.
    Type: Application
    Filed: May 31, 2007
    Publication date: November 8, 2007
    Applicant: Komatsu Denshi Kinzoku Kabushiki Kaisha
    Inventors: Hiroshi Inagaki, Shigeki Kawashima, Makoto Kamogawa, Toshirou Kotooka, Toshiaki Saishoji, Daisuke Ebi, Kentaro Nakamura, Kengo Hayashi, Yoshinobu Hiraishi, Shigeo Morimoto, Hiroshi Monden, Tadayuki Hanamoto, Tadashi Hata
  • Publication number: 20070240629
    Abstract: The present invention relates to a method for manufacturing a silicon single crystal by pulling up the silicon single crystal from a molten silicon by the CZ method, comprising: a cooling step of cooling the silicon single crystal by a cooler surrounding the silicon single crystal, and a heat shield body disposed surrounding an outer side and a lower side of the cooler while the silicon single crystal is being pulled up; and an Ms adjusting step of determining, in advance, an allowable range of a pulling speed at which a silicon single crystal having few crystal defects can be obtained by adjusting a distance (referred to “Ms”) from the lower surface of the heat shield body disposed on the lower side of the cooler to the surface of the molten silicon, wherein the silicon single crystal 11 is pulled up at a pulling speed within the allowable range thus determined.
    Type: Application
    Filed: April 10, 2007
    Publication date: October 18, 2007
    Inventors: Toshirou Kotooka, Takashi Yokoyama, Kazuyoshi Sakatani, Toshiaki Saishoji, Koichi Shimomura, Ryota Suewaka
  • Publication number: 20070227439
    Abstract: A method for controlling the temperature gradient on the side surface of a silicon single crystal, the height of a solid-liquid interface, and the oxygen concentration in the longitudinal direction of the silicon single crystal is provided in order to manufacture a defect-free silicon single crystal whose oxygen concentration is controlled to a predetermined value rapidly and stably. By disposing a cylindrical cooler around the silicon single crystal, and adjusting the pulling speed of the silicon single crystal, the rotation speed of a crucible that stores molten silicon and the rotation speed of the silicon single crystal, and the output ratio of a multi-heater separated into at least two in the longitudinal direction of the silicon single crystal disposed around the crucible, the temperature gradient on the side surface, the height of the solid-liquid interface, and the oxygen concentration in the longitudinal direction of the silicon single crystal are controlled.
    Type: Application
    Filed: March 27, 2007
    Publication date: October 4, 2007
    Inventors: Takashi Yokoyama, Toshiaki Saishoji, Toshirou Kotooka, Kazuyoshi Sakatani
  • Patent number: 7141113
    Abstract: A method for growing a silicon crystal by a Czochralsky method, wherein, let a pulling speed be V (mm/min) and an average value of an in-crystal temperature gradient in a pulling axis direction within a temperature range, a silicon melting point to 1350° C., be G (° C./mm), V/G ranges from 0.16 to 0.18 mm2/° C. min between a crystal center position and a crystal outer periphery position, and a ratio G outer/G center of an average value G of an in-crystal temperature gradient in a pulling axis direction within a temperature range, a silicon melting point to 1350° C., at a crystal outer surface to that at a crystal center is set to up to 1.10 to thereby obtain a high-quality perfect crystal silicon wafer. Such a perfect crystal silicon wafer, wherein an oxygen concentration is controlled to up to 13×1017 atoms/cm3, an initial heat treatment temperature is at least up to 500° C. and a temperature is raised at up to 1° C./min at least within 700 to 900° C.
    Type: Grant
    Filed: November 19, 1999
    Date of Patent: November 28, 2006
    Assignee: Komatsu Denshi Kinzoku Kabushiki Kaisha
    Inventors: Kozo Nakamura, Toshiaki Saishoji, Hirotaka Nakajima, Shinya Sadohara, Masashi Nishimura, Toshirou Kotooka, Yoshiyuki Shimanuki
  • Publication number: 20060016387
    Abstract: The production yield about defect free devices is improved by so controlling the size and density of void defects that they are under predetermined levels without marring the productivity. The pull-up speed V of a silicon crystal (10) by a pull-up mechanism (4) is controlled, and the rate of cooling by a cooler (30) is also controlled. As a result, the axial temperature gradient G1 at and near the melting point of the silicon crystal (10) is increased. The growth condition V/G1 is lowered to a temperature near the critical value under the condition that the growth rate V lies in the range from 97% to 75% of the limit rate Vmax and that the solid-liquid interface is convex with respect to the melt surface. Thus a silicon crystal (10) is grown by pulling up.
    Type: Application
    Filed: November 14, 2003
    Publication date: January 26, 2006
    Inventors: Takashi Yokoyama, Koji Yoshihara, Toshiaki Saishoji, Kozo Nakamura, Ryota Suewa
  • Patent number: 6977010
    Abstract: In a Czochralski (CZ) single crystal puller equipped with a cooler and a thermal insulation member, which are to be disposed in a CZ furnace, smooth recharge and additional charge of material are made possible. Further, elimination of dislocations from a silicon seed crystal by use of the Dash's neck method can be performed smoothly. To these ends, there is provided a CZ single crystal puller, wherein a cooler and a thermal insulation member are immediately moved upward away from a melt surface during recharge or additional charge of material or during elimination of dislocations from a silicon seed crystal by use of the Dash's neck method.
    Type: Grant
    Filed: January 7, 2003
    Date of Patent: December 20, 2005
    Assignee: Komatsu Denshi Kinzoku Kabushiki Kaisha
    Inventors: Hiroshi Inagaki, Shigeki Kawashima, Makoto Kamogawa, Toshirou Kotooka, Toshiaki Saishoji, Daisuke Ebi, Kentaro Nakamura, Kengo Hayashi, Yoshinobu Hiraishi, Shigeo Morimoto, Hiroshi Monden, Tadayuki Hanamoto, Tadashi Hata
  • Publication number: 20050268840
    Abstract: In a Czochralski (CZ) single crystal puller equipped with a cooler and a thermal insulation member, which are to be disposed in a CZ furnace, smooth recharge and additional charge of material are made possible. Further, elimination of dislocations from a silicon seed crystal by use of the Dash's neck method can be performed smoothly. To these ends, there is provided a CZ single crystal puller, wherein a cooler and a thermal insulation member are immediately moved upward away from a melt surface during recharge or additional charge of material or during elimination of dislocations from a silicon seed crystal by use of the Dash's neck method.
    Type: Application
    Filed: June 7, 2005
    Publication date: December 8, 2005
    Applicant: Komatsu Denshi Kinzoku Kabushiki Kaisha
    Inventors: Hiroshi Inagaki, Shigeki Kawashima, Makoto Kamogawa, Toshirou Kotooka, Toshiaki Saishoji, Daisuke Ebi, Kentaro Nakamura, Kengo Hayashi, Yoshinobu Hiraishi, Shigeo Morimoto, Hiroshi Monden, Tadayuki Hanamoto, Tadashi Hata
  • Patent number: 6869478
    Abstract: A method for producing a silicon ingot having no defect over a wide range of region with stability and good reproducibility, wherein when a silicon single crystal (11) is pulled up form a silicon melt (13), the shape of a solid-liquid interface (14) which a boundary between the silicon melt (13) and the silicon single crystal (11) and the temperature distribution on the side face (11b) of a single crystal under being pulled up are appropriately controlled.
    Type: Grant
    Filed: March 19, 2001
    Date of Patent: March 22, 2005
    Assignee: Komatsu Denshi Kinzoku Kabushiki Kaisha
    Inventors: Kozo Nakamura, Toshiaki Saishoji, Shinji Togawa, Toshirou Kotooka, Susumu Maeda
  • Publication number: 20030154907
    Abstract: In a Czochralski (CZ) single crystal puller equipped with a cooler and a thermal insulation member, which are to be disposed in a CZ furnace, smooth recharge and additional charge of material are made possible. Further, elimination of dislocations from a silicon seed crystal by use of the Dash's neck method can be performed smoothly. To these ends, there is provided a CZ single crystal puller, wherein a cooler and a thermal insulation member are immediately moved upward away from a melt surface during recharge or additional charge of material or during elimination of dislocations from a silicon seed crystal by use of the Dash's neck method.
    Type: Application
    Filed: January 7, 2003
    Publication date: August 21, 2003
    Applicant: Komatsu Denshi Kinzoku Kabushiki Kaisha
    Inventors: Hiroshi Inagaki, Shigeki Kawashima, Makoto Kamogawa, Toshirou Kotooka, Toshiaki Saishoji, Daisuke Ebi, Kentaro Nakamura, Kengo Hayashi, Yoshinobu Hiraishi, Shigeo Morimoto, Hiroshi Monden, Tadayuki Hanamoto, Tadashi Hata
  • Publication number: 20030041796
    Abstract: A method for producing a silicon ingot having no defect over a wide range of region with stability and good reproducibility, wherein when a silicon single crystal (11) is pulled up form a silicon melt (13), the shape of a solid-liquid interface (14) which a boundary between the silicon melt (13) and the silicon single crystal (11) and the temperature distribution on the side face (11b) of a single crystal under being pulled up are appropriately controlled.
    Type: Application
    Filed: September 23, 2002
    Publication date: March 6, 2003
    Inventors: Kozo Nakamura, Toshiaki Saishoji, Shinji Togawa, Toshirou Kotooka, Susumu Maeda
  • Publication number: 20020144641
    Abstract: In a Czochralski (CZ) single crystal puller equipped with a cooler and a thermal insulation member, which are to be disposed in a CZ furnace, smooth recharge and additional charge of material are made possible. Further, elimination of dislocations from a silicon seed crystal by use of the Dash's neck method can be performed smoothly. To these ends, there is provided a CZ single crystal puller, wherein a cooler and a thermal insulation member are immediately moved upward away from a melt surface during recharge or additional charge of material or during elimination of dislocations from a silicon seed crystal by use of the Dash's neck method.
    Type: Application
    Filed: February 1, 2001
    Publication date: October 10, 2002
    Inventors: Hiroshi Inagaki, Shigeki Kawashima, Makoto Kamogawa, Toshire Kotooka, Toshiaki Saishoji, Daisuke Ebi, Kentarou Nakamura, Kengo Hayashi, Yoshinobu Hiraishi, Shigeo Morimoto, Hiroshi Monden, Tadayuki Hanamoto, Tadashi Hata
  • Patent number: 6273944
    Abstract: In growing silicon single crystals by the CZ method, the cooling rate in the 1150-1080° C. temperature zone (defect-forming temperature range) where the grown-in defects are formed is set at more than 2.0° C./min to manufacture single crystals having an as-grown LSTD density of larger than 3.0×106/cm3 or a FPD density of larger than 6.0×105/cm3. As this single crystal has a small defect size, thus the dissolution rate of the defects increases by the heat treatment in a non-oxidizing atmosphere containing a hydrogen gas, so the effect of the hydrogen heat treatment can extend to the depth more than 3 &mgr;m from the wafer surface.
    Type: Grant
    Filed: April 6, 2000
    Date of Patent: August 14, 2001
    Assignee: Komatsu Electronic Metals Co., Ltd.
    Inventors: Toshiaki Saishoji, Kozo Nakamura, Junsuke Tomioka
  • Patent number: 6179910
    Abstract: This invention provides a method for manufacturing silicon single crystals. The method is capable of eliminating void defects existing in deep regions of a silicon single crystal despite the size of the silicon single crystal. The silicon single crystals according to this invention are pulled the radius of a ring-shaped oxidation induced stacking fault (OSF ring) of a wafer is larger than half the radius of the wafer during the process of thermal oxidation treatment.
    Type: Grant
    Filed: September 14, 1999
    Date of Patent: January 30, 2001
    Assignee: Komatsu Electronic Metals Co., LTD
    Inventors: Takashi Yokoyama, Shin Matsukuma, Toshiaki Saishoji, Kozo Nakamura, Junsuke Tomioka
  • Patent number: 6056931
    Abstract: In growing silicon single crystals by the CZ method, the cooling rate in the 1150-1080.degree. C. temperature zone (defect-forming temperature range) where the grown-in defects are formed is set at more than 2.0.degree. C./min to manufacture single crystals having an as-grown LSTD density of larger than 3.0.times.10.sup.6 /cm.sup.3 or a FPD density of larger than 6.0.times.10.sup.5 /cm.sup.3. As this single crystal has a small defect size, thus the dissolution rate of the defects increases by the heat treatment in a non-oxidizing atmosphere containing a hydrogen gas, so the effect of the hydrogen heat treatment can extend to the depth more than 3 .mu.m from the wafer surface.
    Type: Grant
    Filed: January 27, 1998
    Date of Patent: May 2, 2000
    Assignee: Komatsu Electronic Metal Co., Ltd.
    Inventors: Toshiaki Saishoji, Kozo Nakamura, Junsuke Tomioka