Patents by Inventor Ryoji Hoshi

Ryoji Hoshi 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: 8083852
    Abstract: A silicon single crystal growth method of pulling up and growing a single crystal from a melt of a silicon raw material melted in a quartz crucible based on a Czochralski method, the method comprising the steps of: applying a direct current voltage in such a manner that an outer wall of the quartz crucible acts as a positive electrode and an electrode immersed into the melt of the silicon raw material acts as a negative electrode, the immersed electrode being placed separately from a pulling member for pulling the single crystal; and growing the single crystal with the pulling member while passing an electric current through the electrode, and a pulling apparatus thereof.
    Type: Grant
    Filed: March 24, 2009
    Date of Patent: December 27, 2011
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Kosei Sugawara, Ryoji Hoshi, Masanori Takazawa, Yuuichi Miyahara, Atsushi Iwasaki
  • Patent number: 7909930
    Abstract: A method for producing a silicon single crystal by the Czochralski method with carbon-doping comprising: charging a polycrystalline silicon material and any one of a carbon dopant selected from the group consisting of an organic compound, an organic compound and a silicon wafer, carbon powder and a silicon wafer, an organic compound and carbon powder, and an organic compound and carbon powder and a silicon wafer into a crucible and melting the polycrystalline silicon material and the carbon dopant; and then growing a silicon single crystal from the melt of the polycrystalline silicon material and the carbon dopant. And a carbon-doped silicon single crystal produced by the method. Thereby, there is provided a method for producing a silicon single crystal with carbon-doping in which the crystal can be doped with carbon easily at low cost, and carbon concentration in the crystal can be controlled precisely.
    Type: Grant
    Filed: March 31, 2005
    Date of Patent: March 22, 2011
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Ryoji Hoshi, Naoki Nagai, Izumi Fusegawa
  • Publication number: 20110017125
    Abstract: A silicon single crystal growth method of pulling up and growing a single crystal from a melt of a silicon raw material melted in a quartz crucible based on a Czochralski method, the method comprising the steps of: applying a direct current voltage in such a manner that an outer wall of the quartz crucible acts as a positive electrode and an electrode immersed into the melt of the silicon raw material acts as a negative electrode, the immersed electrode being placed separately from a pulling member for pulling the single crystal; and growing the single crystal with the pulling member while passing an electric current through the electrode, and a pulling apparatus thereof.
    Type: Application
    Filed: March 24, 2009
    Publication date: January 27, 2011
    Applicant: SHIN-ETSU HANDOTAI CO., LTD.
    Inventors: Kosei Sugawara, Ryoji Hoshi, Masanori Takazawa, Yuuichi Miyahara, Atsushi Iwasaki
  • Publication number: 20100258050
    Abstract: The present invention is an apparatus for producing a single crystal, growing the single crystal by the Czochralski method and comprising at least: a main chamber in which a crucible for accommodating a raw material melt and a heater for heating the raw material melt are arranged; a pulling chamber into which the grown single crystal is pulled and accommodated, the pulling chamber being continuously provided above the main chamber; and a cooling cylinder extending at least from a ceiling of the main chamber toward a surface of the raw material melt so as to surround the single crystal during pulling, the cooling cylinder being forcibly cooled with a cooling medium. As a result, there is provided an apparatus for producing a single crystal that can increase the growth rate of the single crystal by efficiently cooling the single crystal during the growth.
    Type: Application
    Filed: December 18, 2008
    Publication date: October 14, 2010
    Applicant: SHIN-ETSU HANDOTAI CO., LTD.
    Inventors: Ryoji Hoshi, Kiyotaka Takano
  • Publication number: 20100116195
    Abstract: The present invention provides a method for growing a carbon-doped silicon single crystal that grows a silicon single crystal from a raw material melt in a crucible having carbon added therein by the Czochralski method, wherein an extruded material or a molded material is used as a dopant for adding the carbon to a raw material in the crucible. As a result, there can be provided the method for growing a carbon-doped silicon single crystal, by which the carbon can be easily doped in the silicon single crystal at low cost and a carbon concentration in the silicon single crystal can be accurately controlled in a silicon single crystal pulling up process by the Czochralski method.
    Type: Application
    Filed: April 18, 2008
    Publication date: May 13, 2010
    Applicant: SHIN-ETSU HANDOTAI CO., LTD.
    Inventors: Ryoji Hoshi, Susumu Sonokawa
  • Patent number: 7713851
    Abstract: A silicon epitaxial layer 2 is grown in vapor phase on a silicon single crystal substrate 1 manufactured by the Czochralski method, and doped with boron so as to adjust the resistivity to 0.02 ?·cm or below, oxygen precipitation nuclei 11 are formed in the silicon single crystal substrate 1, by carrying out annealing at 450° C. to 750° C., in an oxidizing atmosphere, for a duration of time allowing formation of a silicon oxide film only to as thick as 2 nm or below on the silicon epitaxial layer 2 as a result of the annealing, and thus-formed silicon oxide film 3 is etched as the first cleaning after the low-temperature annealing, using a cleaning solution. By this process, the final residual thickness of the silicon oxide film can be suppressed only to a level equivalent to native oxide film, without relying upon the hydrofluoric acid cleaning.
    Type: Grant
    Filed: August 3, 2005
    Date of Patent: May 11, 2010
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Fumitaka Kume, Tomosuke Yoshida, Ken Aihara, Ryoji Hoshi, Satoshi Tobe, Naohisa Toda, Fumio Tahara
  • 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
  • Patent number: 7594966
    Abstract: A method for producing a single crystal by pulling a single crystal from a raw material melt in a chamber according to the Czochralski method, including pulling a single crystal having a defect-free region, which is outside an OSF region, to occur in a ring shape in the radial direction, and in which interstitial-type and vacancy-type defects do not exist. The pulling of the single crystal is controlled so that an average cooling rate in passing through a temperature region of the melting point of the single crystal to 950° C. is in the range of 0.96° C./min or more, an average cooling rate in passing through a temperature region of 1150° C. to 1080° C. is in the range of 0.88° C./min or more, and an average cooling rate in passing through a temperature region of 1050° C. to 950° C. is in the range of 0.71° C./min or more.
    Type: Grant
    Filed: October 19, 2004
    Date of Patent: September 29, 2009
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Ryoji Hoshi, Susumu Sonokawa
  • Publication number: 20080184928
    Abstract: The present invention is a method for producing a single crystal that is a multi-pulling method for pulling a plurality of single crystals 3 from a raw material melt 4 in a same crucible in a chamber by a Czochralski method, comprising steps of: pulling a single crystal 3 from a raw material melt 4; then additionally charging polycrystalline raw material in a residual raw material melt 4 without turning off power of a heater 7, and melting the polycrystalline raw material; then pulling a next single crystal 3; and repeating the steps and thereby pulling the plurality of single crystals 3; wherein in a case of setting a ratio of a pulling rate V and crystal temperature gradient G near a solid-liquid interface along a pulling axis direction when a straight body of the single crystal 3 is grown to be V/G, in order to control the V/G of each of the single crystals 3 to be pulled to a predetermined value, a pulling condition such as the pulling rate V is preliminarily modified according to an elapsed time from beg
    Type: Application
    Filed: October 21, 2005
    Publication date: August 7, 2008
    Applicant: SHIN-ETSU HANDOTAI CO., LTD.
    Inventors: Ryoji Hoshi, Takahiro Yanagimachi
  • Patent number: 7396405
    Abstract: There is disclosed a single crystal obtained by a single crystal pulling method, wherein an interval of striations incorporated into the single crystal due to temperature fluctuation of crystal melt at the time of crystal growth is controlled, and a method of growing a single crystal according to a single crystal pulling method, wherein a growth rate and/or a temperature fluctuation period are controlled so that V×F/sin ? may be in a certain range when a growth rate at the time of growing a single crystal is defined as V (mm/min), a temperature fluctuation period of crystal melt is defined as F (min), and an angle to the level surface of a crystal-growth interface is defined as ?.
    Type: Grant
    Filed: September 8, 2003
    Date of Patent: July 8, 2008
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Ryoji Hoshi, Susumu Sonokawa
  • Publication number: 20080038526
    Abstract: A silicon epitaxial wafer 100 formed by growing a silicon epitaxial layer 2 on a silicon single crystal substrate 1, produced by a CZ method, and doped with boron so that a resistivity thereof is in the range of 0.009 ?·cm or higher and 0.012 ?·cm or lower. The silicon single crystal substrate 1 has a density of the oxygen precipitation nuclei of 1×1010 cm?3 or higher. A width of a no-oxygen-precipitation-nucleus-forming-region 15, formed between the silicon epitaxial layer 2 and the silicon single substrate 1, is in the range of more than 0 ?m and less than 10 ?m. Thereby, provided is a silicon epitaxial wafer using a boron doped p+ CZ substrate, wherein a formed width of no-oxygen-precipitation-nucleus-forming-region is reduced sufficiently, and oxygen precipitates can be formed having a density sufficient enough to exert an IG effect.
    Type: Application
    Filed: July 5, 2005
    Publication date: February 14, 2008
    Applicant: Shin-Etsu Handotai Co., Ltd.
    Inventors: Fumitaka Kume, Tomosuke Yushida, Ken Aihara, Ryoji Hoshi, Satoshi Tobe, Naohisa Toda, Fumio Tahara
  • Publication number: 20070266930
    Abstract: A method for producing a silicon single crystal by the Czochralski method with carbon-doping comprising: charging a polycrystalline silicon material and any one of a carbon dopant selected from the group consisting of an organic compound, an organic compound and a silicon wafer, carbon powder and a silicon wafer, an organic compound and carbon powder, and an organic compound and carbon powder and a silicon wafer into a crucible and melting the polycrystalline silicon material and the carbon dopant; and then growing a silicon single crystal from the melt of the polycrystalline silicon material and the carbon dopant. And a carbon-doped silicon single crystal produced by the method. Thereby, there is provided a method for producing a silicon single crystal with carbon-doping in which the crystal can be doped with carbon easily at low cost, and carbon concentration in the crystal can be controlled precisely.
    Type: Application
    Filed: March 31, 2005
    Publication date: November 22, 2007
    Inventors: Ryoji Hoshi, Naoki Nagai, Izumi Fusegawa
  • Publication number: 20070269338
    Abstract: A silicon epitaxial wafer 100 is formed by growing a silicon epitaxial layer 2 on a silicon single crystal substrate 1, produced by means of a CZ method, and doped with boron so that a resistivity thereof is less than 0.018 ?·cm. The silicon single crystal substrate 1 has a density of bulk stacking faults 13 in the silicon single crystal substrate 1 in the range of 1×108 cm?3 or higher and 3×109 cm?3 or lower. Thereby, provided is a silicon epitaxial wafer having a boron doped p+ CZ substrate with a resistivity of 0.018?·cm or lower, and a state of formation of oxygen precipitates can be adjusted adequately so as to secure a sufficient IG effect and to suppress a problem of bow and deformation of a substrate, despite that sizes of oxygen precipitates is so small to be observed accurately.
    Type: Application
    Filed: June 27, 2005
    Publication date: November 22, 2007
    Applicant: Shin-Etsu Handotai Co., Ltd
    Inventors: Fumitaka Kume, Tomosuke Yoshida, Ken Aihara, Ryoji Hoshi, Satoshi Tobe, Naohisa Toda, Fumio Tahara
  • Publication number: 20070243699
    Abstract: A silicon epitaxial layer 2 is grown in vapor phase on a silicon single crystal substrate 1 manufactured by the Czochralski method, and doped with boron so as to adjust the resistivity to 0.02 ?·cm or below, oxygen precipitation nuclei 11 are formed in the silicon single crystal substrate 1, by carrying out annealing at 450° C. to 750° C., in an oxidizing atmosphere, for a duration of time allowing formation of a silicon oxide film only to as thick as 2 nm or below on the silicon epitaxial layer 2 as a result of the annealing, and thus-formed silicon oxide film 3 is etched as the first cleaning after the low-temperature annealing, using a cleaning solution. By this process, the final residual thickness of the silicon oxide film can be suppressed only to a level equivalent to native oxide film, without relying upon the hydrofluoric acid cleaning.
    Type: Application
    Filed: August 3, 2005
    Publication date: October 18, 2007
    Applicant: Shin-Etsu Handotai Co., Ltd.
    Inventors: Fumitaka Kume, Tomosuke Yoshida, Ken Aihara, Ryoji Hoshi, Satoshi Tobe, Naohisa Toda, Fumio Tahara
  • Patent number: 7204881
    Abstract: There are disclosed a silicon wafer for epitaxial growth wherein the wafer is produced by slicing a silicon single crystal grown with doping nitrogen according to the Czochralski method (CZ method) in the region where at least the center of the wafer becomes V region in which the void type defects are generated, and wherein the number of defects having an opening size of 20 nm or less among the void type defects appearing on the surface of the wafer is 0.02/cm2 or less, and an epitalial wafer wherein an epitaxial layer is formed on the silicon wafer for epitaxial growth. Thereby, there can be produced an epitaxial wafer having a high gettering capability wherein very few SF exist in the epitaxial layer easily at high productivity and at low cost.
    Type: Grant
    Filed: July 8, 2003
    Date of Patent: April 17, 2007
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Ryoji Hoshi, Susumu Sonokawa
  • Patent number: 7201801
    Abstract: The present invention provides a heater for manufacturing a crystal by the Czochralski method comprising at least terminal portions supplied with current and a heat generating portion by resistance heating, and being arranged so as to surround a crucible containing a raw material melt, wherein the heater has a uniform heat generation distribution to the raw material melt after deformation while in use during crystal manufacture. It is thus possible to prevent hindrance of monocrystallization and unstable crystal quality caused by ununiform temperature in the raw material melt due to deformation of the shape of the heater's heat generating portion while in use during crystal manufacture.
    Type: Grant
    Filed: September 8, 2003
    Date of Patent: April 10, 2007
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Susumu Sonokawa, Ryoji Hoshi, Wataru Sato, Tomohiko Ohta
  • Publication number: 20060272570
    Abstract: The present invention provides a method for producing a single crystal by pulling a single crystal from a raw material melt in a chamber in accordance with Czochralski method, comprising pulling a single crystal having a defect-free region which is outside an OSF region to occur in a ring shape in the radial direction and which interstitial-type and vacancy-type defects do not exist in, wherein the pulling of the single crystal is performed with being controlled so that an average of cooling rate in passing through a temperature region of the melt point of the single crystal to 950° C. is in the range of 0.96° C./min or more and so that an average of cooling rate in passing through a temperature region of 1150° C. to 1080° C. is in the range of 0.88° C./min or more and so that an average of cooling rate in passing through a temperature region of 1050° C. to 950° C. is in the range of 0.71° C./min or more.
    Type: Application
    Filed: October 19, 2004
    Publication date: December 7, 2006
    Applicant: Shin-Etsu Handotai Co., Ltd.
    Inventors: Ryoji Hoshi, Susumu Sonokawa
  • Publication number: 20060191468
    Abstract: A method of producing a single crystal according to Czochralski method comprising the steps of, charging polycrystalline material into a crucible, heating and melting the polycrystalline material by a heater disposed so as to surround the crucible, immersing a seed crystal into the material melt and then pulling the seed crystal to grow a single crystal, wherein in the case of growing a single crystal of which resistivity is controlled by doping with boron, the highest temperature of the crucible is controlled to be 1600° C. or less to grow the single crystal. Thereby, there is provided a method of producing a single crystal in which generation of dislocation is prevented when a single crystal having high gettering property and doped with boron is produced, and thus the single crystal can be produced at high productivity and at low cost.
    Type: Application
    Filed: March 30, 2004
    Publication date: August 31, 2006
    Applicant: Shin-Etsu Handotai Co., Ltd.
    Inventors: Ryoji Hoshi, Susumu Sonokawa
  • Publication number: 20050263062
    Abstract: There is disclosed a single crystal obtained by a single crystal pulling method, wherein an interval of striations incorporated into the single crystal due to temperature fluctuation of crystal melt at the time of crystal growth is controlled, and a method of growing a single crystal according to a single crystal pulling method, wherein a growth rate and/or a temperature fluctuation period are controlled so that V×F/sin ? may be in a certain range when a growth rate at the time of growing a single crystal is defined as V (mm/min), a temperature fluctuation period of crystal melt is defined as F (min), and an angle to the level surface of a crystal-growth interface is defined as ?.
    Type: Application
    Filed: September 8, 2003
    Publication date: December 1, 2005
    Inventors: Ryoji Hoshi, Susumu Sonokawa