Patents by Inventor Masahiko Urano

Masahiko Urano 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: 10113247
    Abstract: A single crystal pulling apparatus including: a remelting detection apparatus which detects that remelting of a lower end portion of the semiconductor single crystal is completed from a change in weight of the semiconductor single crystal when the lower end portion of the semiconductor single crystal is immersed in the melt to be remolten by using the wire; and a lowermost end detection apparatus which detects a lowermost end of the semiconductor single crystal from a position where no current flows between the semiconductor single crystal and the melt when the semiconductor single crystal is taken up with the use of the wire while applying a voltage between the semiconductor single crystal and the melt by applying a voltage between the crucible and the wire.
    Type: Grant
    Filed: September 9, 2015
    Date of Patent: October 30, 2018
    Assignee: SHIN-ETSU HANDOTAI CO., LTD.
    Inventors: Naoki Masuda, Masahiko Urano
  • Publication number: 20170292205
    Abstract: A single crystal pulling apparatus including: a remelting detection apparatus which detects that remelting of a lower end portion of the semiconductor single crystal is completed from a change in weight of the semiconductor single crystal when the lower end portion of the semiconductor single crystal is immersed in the melt to be remolten by using the wire; and a lowermost end detection apparatus which detects a lowermost end of the semiconductor single crystal from a position where no current flows between the semiconductor single crystal and the melt when the semiconductor single crystal is taken up with the use of the wire while applying a voltage between the semiconductor single crystal and the melt by applying a voltage between the crucible and the wire.
    Type: Application
    Filed: September 9, 2015
    Publication date: October 12, 2017
    Applicant: SHIN-ETSU HANDOTAI CO., LTD.
    Inventors: Naoki MASUDA, Masahiko URANO
  • Patent number: 9650724
    Abstract: A method of charging raw material, includes: storing the material in a recharge tube including a quartz cylinder for storing the material and a conical valve for opening or closing an opening at a lower end of the cylinder; installing the recharge tube storing the raw material in a chamber; and feeding the raw material stored in the recharge tube into the crucible by locating the recharge tube and crucible such that a distance between the lower end of the recharge tube and raw material or melt in the crucible ranges from 200 to 250 mm, and lowering the conical valve to open the opening while simultaneously lowering the crucible such that a ratio CL/SL of the lowering speed of the crucible to the lowering speed of the conical valve ranges from 1.3 to 1.45. The method can inhibit damage of the quartz crucible and recharge tube.
    Type: Grant
    Filed: October 28, 2013
    Date of Patent: May 16, 2017
    Assignee: SHIN-ETSU HANDOTAI CO., LTD.
    Inventors: Katsuyuki Kitagawa, Masahiko Urano, Katsuhiro Yoshida
  • Patent number: 9260796
    Abstract: A method for measuring a distance between a lower end surface of a heat insulating member and a surface of a raw material melt with a reference reflector provided at a lower end of the heat insulating member which is located above the surface of the raw material melt when a silicon single crystal is pulled up by a Czochralski method while a magnetic field is applied to the raw material melt in a crucible is disclosed.
    Type: Grant
    Filed: January 10, 2008
    Date of Patent: February 16, 2016
    Assignee: SHIN-ETSU HANDOTAI CO., LTD.
    Inventors: Ryoji Hoshi, Masahiko Urano, Susumu Sonokawa
  • Publication number: 20150233013
    Abstract: A method of charging raw material, includes: storing the material in a recharge tube including a quartz cylinder for storing the material and a conical valve for opening or closing an opening at a lower end of the cylinder, installing the recharge tube storing the raw material in a chamber; and feeding the raw material stored in the recharge tube into the crucible by locating the recharge tube and crucible such that a distance between the lower end of the recharge tube and raw material or melt in the crucible ranges from 200 to 250 mm, and lowering the conical valve to open the opening while simultaneously lowering the crucible such that a ratio CL/SL of the lowering speed of the crucible to the lowering speed of the conical valve ranges from 1.3 to 1.45. The method can inhibit damage of the quartz crucible and recharge tube.
    Type: Application
    Filed: October 28, 2013
    Publication date: August 20, 2015
    Inventors: Katsuyuki Kitagawa, Masahiko Urano, Katsuhiro Yoshida
  • Patent number: 8885915
    Abstract: A method for measuring a distance between a lower end surface of a heat shielding member including a criterion reflector inside a concavity on the lower end surface and a surface of a raw material melt includes: a silicon single crystal is pulled by the Czochralski method while a magnetic field is applied to the raw material melt in a crucible, measuring the distance between the lower end surface of the heat shielding member and the surface of the raw material melt and observing a position of a mirror image of the criterion reflector with a fixed point observation apparatus; and measuring a movement distance of the mirror image with the apparatus and calculating the distance between the lower end surface of the heat shielding member and the surface of the raw material melt from the movement distance of the image and the measured distance.
    Type: Grant
    Filed: April 28, 2011
    Date of Patent: November 11, 2014
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Kosei Sugawara, Masahiko Urano, Ryoji Hoshi
  • Patent number: 8764900
    Abstract: The present invention provides an apparatus for producing single crystals according to the Czochralski method, the apparatus including a chamber that can be divided into a plurality of chambers; at least one of the plurality of divided chambers having a circulating coolant passage in which a circulating coolant for cooling the chamber circulates; and measuring means that respectively measure an inlet temperature, an outlet temperature, and a circulating coolant flow rate of the circulating coolant in the circulating coolant passage; the apparatus further including a calculating means that calculates a quantity of heat removed from the chamber and/or a proportion of the quantity of removed heat, from the measured values of the inlet temperature, outlet temperature, and circulating coolant flow rate; and a pulling rate control means that controls a pulling rate of the single crystal based on the resulting quantity of removed heat and/or the resulting proportion of the quantity of removed heat.
    Type: Grant
    Filed: August 20, 2007
    Date of Patent: July 1, 2014
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Kiyotaka Takano, Masahiko Urano, Ryoji Hoshi
  • Publication number: 20130058540
    Abstract: A method for measuring a distance between a lower end surface of a heat shielding member including a criterion reflector inside a concavity on the lower end surface and a surface of a raw material melt includes: a silicon single crystal is pulled by the Czochralski method while a magnetic field is applied to the raw material melt in a crucible, measuring the distance between the lower end surface of the heat shielding member and the surface of the raw material melt and observing a position of a mirror image of the criterion reflector with a fixed point observation apparatus; and measuring a movement distance of the mirror image with the apparatus and calculating the distance between the lower end surface of the heat shielding member and the surface of the raw material melt from the movement distance of the image and the measured distance.
    Type: Application
    Filed: April 28, 2011
    Publication date: March 7, 2013
    Applicant: SHIN-ETSU HANDOTAI CO., LTD.
    Inventors: Kosei Sugawara, Masahiko Urano, Ryoji Hoshi
  • Patent number: 8085985
    Abstract: The present invention is a method for determining a relative distance between a reference member placed above a melt surface and the melt surface upon pulling a silicon single crystal out of a raw material melt in a crucible by a CZ method characterized by at least: pulling the silicon single crystal applying a magnetic field; taking a picture of a real image of the reference member and a mirror image of the reference member reflected on the melt surface with a detector; processing the picture taken of the real image and the mirror image of the reference member as different pictures by separating the picture taken; and calculating the relative distance between the real image and the mirror image of the reference member from the processed pictures to determine the relative distance between the reference member and the melt surface.
    Type: Grant
    Filed: January 31, 2007
    Date of Patent: December 27, 2011
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Masahiko Urano, Izumi Fusegawa
  • Publication number: 20100064964
    Abstract: There is provided in the present invention a method for measuring a distance between a lower end surface of a heat insulating member 14 and a surface of a raw material melt 4 when a silicon single crystal is pulled by a Czochralski method while a magnetic field is applied to a raw material melt 4 in a crucible, a reference reflector 18 being located at the lower end of the heat insulating member 14 which is located above the surface of the raw material melt 4, characterized in that the method includes steps of: actually measuring a distance A between the lower end surface of the heat insulating member and the surface of the raw material melt; observing a location R1 of a mirror image of the reference reflector 18 reflected on the surface of the raw material melt by a fixed-point observing apparatus 19; subsequently measuring a travel distance B of the mirror image by the fixed-point observing apparatus 19 while pulling the silicon single crystal; and calculating the distance between the lower end surface of t
    Type: Application
    Filed: January 10, 2008
    Publication date: March 18, 2010
    Applicant: Shin-Etsu Handotai Co., Ltd.
    Inventors: Ryoji Hoshi, Masahiko Urano, Susumu Sonokawa
  • Publication number: 20090249995
    Abstract: The present invention provides an apparatus for producing single crystals according to the Czochralski method, the apparatus including a chamber that can be divided into a plurality of chambers; at least one of the plurality of divided chambers having a circulating coolant passage in which a circulating coolant for cooling the chamber circulates; and measuring means that respectively measure an inlet temperature, an outlet temperature, and a circulating coolant flow rate of the circulating coolant in the circulating coolant passage; the apparatus further including a calculating means that calculates a quantity of heat removed from the chamber and/or a proportion of the quantity of removed heat, from the measured values of the inlet temperature, outlet temperature, and circulating coolant flow rate; and a pulling rate control means that controls a pulling rate of the single crystal based on the resulting quantity of removed heat and/or the resulting proportion of the quantity of removed heat.
    Type: Application
    Filed: August 20, 2007
    Publication date: October 8, 2009
    Applicant: SHIN-ETSU HANDOTAI CO., LTD.
    Inventors: Kiyotaka Takano, Masahiko Urano, Ryoji Hoshi
  • Publication number: 20090232359
    Abstract: The present invention is a method for determining a relative distance between a reference member placed above a melt surface and the melt surface upon pulling a silicon single crystal out of a raw material melt in a crucible by a CZ method characterized by at least: pulling the silicon single crystal applying a magnetic field; taking a picture of a real image of the reference member and a mirror image of the reference member reflected on the melt surface with a detector; processing the picture taken of the real image and the mirror image of the reference member as different pictures by separating the picture taken; and calculating the relative distance between the real image and the mirror image of the reference member from the processed pictures to determine the relative distance between the reference member and the melt surface.
    Type: Application
    Filed: January 31, 2007
    Publication date: September 17, 2009
    Applicant: SHIN-ETSU HANDOTAI CO., LTD.
    Inventors: Masahiko Urano, Izumi Fusegawa
  • Patent number: 6010568
    Abstract: An apparatus and a method capable of automatically adjusting an initial position of the surface of a melt without an operator are provided. In a single crystal puller using a wire as a suspender for a seed crystal for growing a single crystal of silicon or the like according to the CZ method, a reference position of the seed crystal is detected, the wire is unwound to lower the end of the wire to a position higher by a distance W-X from the reference position and then pulled upward above said reference position to correct the wire for an extension due to the weight of a single crystal attached thereto. Also, the wire is left above a melt for about ten minutes to provide a constant amount of extension to the wire due to heat of the melt. These operations are automatically performed.
    Type: Grant
    Filed: January 7, 1999
    Date of Patent: January 4, 2000
    Assignee: Shin-Estu Handotai Co., Ltd.
    Inventors: Masahiko Urano, Atsushi Ozaki, Tomohiro Kakegawa, Hideki Nakano
  • Patent number: 5938841
    Abstract: A novel device for producing a single crystal by the CZ or MCZ method is provided, which comprising a crucible for containing silicon melt therein, a wire reel and a wire for pulling a single crystal, a motor and a rotation shaft for rotating the crucible, a speed change device being inserted between the motor and the rotation shaft, and, if necessary, a magnetic field generator, by which the magnetic field is applied to the melt. According to the device for producing a single crystal, the rotation accuracy of a crucible can be improved, so that the concentrations of impurities in the pulled single crystal can be highly precisely controlled.
    Type: Grant
    Filed: November 21, 1996
    Date of Patent: August 17, 1999
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Kouji Kitagawa, Kouji Mizuishi, Masahiko Urano, Kenji Araki, Eiichi Iino, Izumi Fusegawa
  • Patent number: 5888299
    Abstract: An apparatus and a method capable of automatically adjusting an initial position of the surface of a melt without an operator are provided. In a single crystal puller using a wire as a suspender for a seed crystal for growing a single crystal of silicon or the like according to the CZ method, a reference position of the seed crystal is detected, the wire is unwound to lower the end of the wire to a position higher by a distance W-X from the reference position and then pulled upward above said reference position to correct the wire for an extension due to the weight of a single crystal attached thereto. Also, the wire is left above a melt for about ten minutes to provide a constant amount of extension to the wire due to heat of the melt These operations are automatically performed.
    Type: Grant
    Filed: December 5, 1996
    Date of Patent: March 30, 1999
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Masahiko Urano, Atsushi Ozaki, Tomohiro Kakegawa, Hideki Nakano
  • Patent number: 5882397
    Abstract: In a crystal pulling method in which a growing single crystal is initially pulled by a seed chuck and subsequently pulled by lifting jig in the middle of the pulling operation, the speed Va of the seed chuck relative to the lifting jig is decreased, while the rising speed Vb of the lifting jig increases, from a first point where switching of the pulling mechanism from the seed chuck to the lifting jig is started. The total speed Vt=Vb+Va is constantly maintained at a desired pulling speed V up to a third point where the shifting of the load from the seed chuck to the lifting jig is started. Subsequently, the total speed Vt is made less than the desired pulling speed V from the third point where the shifting of the load from the seed shuck to the lifting jig is started. This enables accurate growth of a crystal.
    Type: Grant
    Filed: October 6, 1997
    Date of Patent: March 16, 1999
    Assignee: Shin Etsu Handotai Co., Ltd.
    Inventors: Eiichi Iino, Makoto Iida, Masahiko Urano, Masanori Kimura, Shozo Muraoka
  • Patent number: 5879448
    Abstract: A method and an apparatus for pulling a single crystal are disclosed. A first neck portion, a convex portion, and a second neck portion are formed in this order under a seed crystal held by a seed chuck, and subsequent to the second neck portion, a single crystal having a diameter-expanding portion and a straight cylindrical portion is formed. Lifting holders are brought around and in proximity to the second neck portion when the second neck portion rises to a predetermined position during the pulling by the seed chuck. The single crystal and the lifting holders are moved relative to each other in the vertical direction to thereby bring the convex portion into contact with the lifting holders in a resting manner, so that part of a load borne by the seed chuck is shifted to the lifting holders. Subsequently, the pulling operation is performed by the lifting holders. Accordingly, a single crystal having a larger weight can be pulled safely while maintaining high quality.
    Type: Grant
    Filed: June 26, 1997
    Date of Patent: March 9, 1999
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Masahiko Urano, Yasushi Nakamura, Seiichiro Otsuka, Eiichi Iino
  • Patent number: 5851286
    Abstract: A crystal pulling apparatus is disclosed which employs the Czochralski method. The crystal pulling apparatus is operated while a heater for heating a material melt in a crucible is controlled by the main controller of a main system. When maintenance of a heating state is disabled for some reason, a relay of a signal changeover circuit is switched so as to maintain the heating state under control of the backup controller of a backup system, thereby maintaining the material melt in a molten state. Thus, even when it becomes impossible for the main system to heat the material melt within the crucible, the material melt can be prevented from becoming solidified.
    Type: Grant
    Filed: December 11, 1996
    Date of Patent: December 22, 1998
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Atsushi Ozaki, Masahiko Urano, Isamu Harada, Tomohiro Kakegawa, Hideki Nakano
  • Patent number: 5419277
    Abstract: An apparatus for producing a semiconductor single-crystal grown by the Czochralski method includes a reference reflector disposed at the lower end of a gas rectifying tube, first and second optical systems disposed above the reference reflector for changing the direction of propagation of light from the horizontal to the vertical, and vice versa, a first position sensor composed of a first light source for emitting a light beam in a horizontal direction toward the first optical system, and a first photosensitive member which receives a reflection light reflected from the melt surface in a crucible, a second position sensor composed of a second light source for emitting a light beam in a horizontal direction toward the second optical system, and a second photosensitive member which receives a reflection light reflected from the reference reflector.
    Type: Grant
    Filed: February 4, 1994
    Date of Patent: May 30, 1995
    Assignee: Shin-Etsu Handotai Co. Ltd.
    Inventors: Masahiko Urano, Michiaki Oda
  • Patent number: 5370077
    Abstract: The present invention provides control of single crystal growth after the recovery from power failure when controlling crystal growth in an automatic mode. A source voltage is supplied to a controller 70 through a no-break power supply 62. At the time of recovery from power failure, the controller continues the automatic operation mode with the same control output as that stored when power failure is detected (84, 85) if the power failure time t is t .ltoreq.t.sub.1 (for example, 1 second), switches the control mode to the manual control mode with the same control output as that stored when the power failure is detected (86, 87) if t.sub.1 <t.ltoreq.t.sub.2 (for example, 5 seconds), stops the crystal growth operation and switches the control mode to the manual control mode (88, 89) if t.sub.2 <t.ltoreq.t.sub.3 (for example, 600 seconds), and separates the grown crystal from a melt 22 by upwardly moving the crystal and upwardly moves a crucible 16 (90) if t>t.sub.3.
    Type: Grant
    Filed: August 24, 1992
    Date of Patent: December 6, 1994
    Assignee: Shin-Etsu Handotai Company, Limited
    Inventors: Yoshihiro Hirano, Atsushi Ozaki, Masahiko Urano