Patents by Inventor Kosei Sugawara
Kosei Sugawara 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).
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Publication number: 20240026565Abstract: A method for measuring distance between lower end surface of heat shielding member and surface of raw material melt, the method including providing the member being located above the melt, when a silicon single crystal is pulled by the Czochralski method while a magnetic field is applied to the melt in a crucible, the method including: forming a through-hole in the member; measuring distance between the member and the melt surface, and observing position of mirror image of the through-hole with fixed point observation apparatus, the mirror image being reflected on the melt surface; then measuring a moving distance of the mirror image, and calculating distance between the member and the melt surface from a measured value and the moving distance of the mirror image, during the pulling of the crystal. The distance between the member and the melt can be precisely measured by the method.Type: ApplicationFiled: October 11, 2021Publication date: January 25, 2024Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Kosei SUGAWARA, Takaki IMAI, Masahiro AKIBA, Katsuyuki KITAGAWA
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Publication number: 20230290835Abstract: The present invention is a nitride semiconductor wafer, including: a silicon single-crystal substrate; and a device layer composed of a nitride semiconductor above the silicon single-crystal substrate, wherein the silicon single-crystal substrate is a CZ silicon single-crystal substrate, and has a resistivity of 1000 ?·cm or more, an oxygen concentration of 5.0×1016 atoms/cm3 (JEIDA) or more and 2.0×1.017 atoms/cm3 (JEIDA) or less, and a nitrogen concentration of 5.0×1014 atoms/cm3 or more. This provides a nitride semiconductor wafer that hardly causes plastic deformation even using a high-resistant low-oxygen silicon single-crystal substrate produced by the CZ method, which is suitably used for a high-frequency device, and that can reduce warpage of the substrate.Type: ApplicationFiled: July 12, 2021Publication date: September 14, 2023Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Keitaro TSUCHIYA, Masaru SHINOMIYA, Kosei SUGAWARA
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Publication number: 20230175166Abstract: The present invention is a single-crystal pulling apparatus including: a pulling furnace which has a heater and a crucible arranged and which has a central axis; and a magnetic field generation device having superconducting coils, where the magnetic field generation device has four of the superconducting coils, two of the superconducting coils are arranged in each of two regions divided by a cross section that includes an X axis, the X axis being a direction of lines of magnetic force at the central axis in the horizontal plane including all the coil axes of the four superconducting coils, and includes the central axis of the pulling furnace so as to have line symmetry about the cross section, the four superconducting coils are all arranged so that the coil axes have an angle within a range of more than ?30° and less than 30° relative to a Y axis, the direction of the lines of magnetic force thereof have line symmetry about the cross section, and in each of the regions, the two superconducting coils generateType: ApplicationFiled: March 19, 2020Publication date: June 8, 2023Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Kiyotaka TAKANO, Wataru YAJIMA, Kosei SUGAWARA, Hiroyuki KAMADA, Tomohiko OHTA
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Publication number: 20230138632Abstract: A single-crystal pulling apparatus including: a pulling furnace having a central axis; and a magnetic field generation device arranged around the pulling furnace and having superconducting coils, the apparatus applying a horizontal magnetic field to the molten semiconductor raw material, two coil axes in the two pairs of the superconducting coils are included in a single horizontal plane, and when a direction of lines of magnetic force at the central axis of the pulling furnace in the horizontal plane is determined as an X axis, a center angle ? having the X axis between the two coil axes is 100 degrees or more and 120 degrees or less. This makes it possible to reduce the height of the coils, to raise the magnetic field center close to the melt surface of the semiconductor raw material, and to obtain a single crystal having a lower oxygen concentration than conventional single crystals.Type: ApplicationFiled: February 22, 2021Publication date: May 4, 2023Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Kiyotaka TAKANO, Kosei SUGAWARA, Hiroyuki KAMADA, Takahide ONAI, Tomohiko OHTA
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Publication number: 20230047427Abstract: A method for producing a silicon single crystal, wherein a silicon nitride powder is introduced into a raw material before start of melting and the silicon single crystal doped with nitrogen is pulled by Czochralski method, wherein nitrogen doping is performed while an upper limit amount of usable silicon nitride powder is limited based on an amount of carbon impurities contained in the silicon nitride powder so that a carbon concentration in the silicon single crystal is equal to or less than allowable value. This makes it possible to achieve the required nitrogen doping amount at low cost while achieving the low carbon-concentration specification.Type: ApplicationFiled: December 1, 2020Publication date: February 16, 2023Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Kosei SUGAWARA, Ryoji HOSHI, Tomohiko OHTA
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Patent number: 11053606Abstract: A method of producing a silicon single crystal, including pulling a silicon single crystal by Czochralski method while a magnetic field is applied to a raw material melt, including: setting a diameter on pulling the silicon single crystal to 300 mm or more, setting a growth axis direction of the silicon single crystal to <111>, and growing the silicon single crystal so as to satisfy a relation of 1096/D?(0.134×M+80×R)/D>0.7, wherein D [mm] is the diameter on pulling the silicon single crystal, M [Gauss] is a central magnetic field strength at a surface of the raw material melt, and R [rpm] is a rotation rate of the silicon single crystal. This makes it possible to produce a <111> crystal with favorable macroscopic RRG distribution and microscopic variation of resistivity.Type: GrantFiled: November 13, 2017Date of Patent: July 6, 2021Assignee: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Kosei Sugawara, Ryoji Hoshi
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Publication number: 20210189589Abstract: The present invention is a method of producing a silicon single crystal, including pulling a silicon single crystal by Czochralski method while a magnetic field is applied to a raw material melt, including: setting a diameter on pulling the silicon single crystal to 300 mm or more, setting a growth axis direction of the silicon single crystal to <111>, and growing the silicon single crystal so as to satisfy a relation of 1096/D?(0.134×M+80×R)/D>0.7, wherein D [mm] is the diameter on pulling the silicon single crystal, M [Gauss] is a central magnetic field strength at a surface of the raw material melt, and R [rpm] is a rotation rate of the silicon single crystal. This makes it possible to produce a <111> crystal with favorable macroscopic RRG distribution and microscopic variation of resistivity.Type: ApplicationFiled: March 3, 2021Publication date: June 24, 2021Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Kosei Sugawara, Ryoji Hoshi
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Publication number: 20190376205Abstract: A method of producing a silicon single crystal, including pulling a silicon single crystal by Czochralski method while a magnetic field is applied to a raw material melt, including: setting a diameter on pulling the silicon single crystal to 300 mm or more, setting a growth axis direction of the silicon single crystal to <111>, and growing the silicon single crystal so as to satisfy a relation of 1096/D?(0.134×M+80×R)/D>0.7, wherein D [mm] is the diameter on pulling the silicon single crystal, M [Gauss] is a central magnetic field strength at a surface of the raw material melt, and R [rpm] is a rotation rate of the silicon single crystal. This makes it possible to produce a <111> crystal with favorable macroscopic RRG distribution and microscopic variation of resistivity.Type: ApplicationFiled: November 13, 2017Publication date: December 12, 2019Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Kosei SUGAWARA, Ryoji HOSHI
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Patent number: 9783912Abstract: A silicon single crystal growing apparatus based on a Czochralski method arranges a graphite crucible inside a graphite heater for heating and a quartz crucible inside the graphite crucible and grows a crystal from a raw material melt filling the quartz crucible, and includes a heater outer heat-insulating member outside the graphite heater, a crucible lower heat-insulating member below the graphite crucible, a crucible upper heat-insulating member above straight bodies of the graphite and quartz crucibles, a crucible outer heat-insulating member outside the straight body of the graphite crucible, a crucible inner heat-insulating member inside the straight bodies of the graphite crucible and the quartz crucible, and a heat shielding member above a liquid surface of the raw material melt, the graphite crucible and the quartz crucible being movable upward and downward in a space enclosed with the crucible upper heat-insulating, crucible outer heat-insulating, and crucible inner heat-insulating members.Type: GrantFiled: August 26, 2013Date of Patent: October 10, 2017Assignee: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Ryoji Hoshi, Kosei Sugawara
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Patent number: 9650725Abstract: The present invention provides a method for manufacturing a silicon single crystal wafer, wherein, under a growth condition that V/G?1.05×(V/G)crt is achieved where V is a growth rate in growth of the silicon single crystal ingot, G is a temperature gradient near a crystal growth interface, and (V/G)crt is a value of V/G when a dominant point defect changes from a vacancy to interstitial Si, a silicon single crystal ingot having oxygen concentration of 7×1017 atoms/cm3 (ASTM'79) or less is grown, and a silicon single crystal wafer which includes a region where the vacancy is dominant and in which FPDs are not detected by preferential etching is manufactured from the grown silicon single crystal ingot. As a result, there is provided the method that enables manufacturing a low-oxygen concentration silicon single crystal wafer that can be preferably used for a power device with good productivity at a low cost.Type: GrantFiled: February 15, 2013Date of Patent: May 16, 2017Assignee: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Ryoji Hoshi, Hiroyuki Kamada, Kosei Sugawara
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Publication number: 20150240379Abstract: A silicon single crystal growing apparatus based on a Czochralski method arranges a graphite crucible inside a graphite heater for heating and a quartz crucible inside the graphite crucible and grows a crystal from a raw material melt filling the quartz crucible, and includes a heater outer heat-insulating member outside the graphite heater, a crucible lower heat-insulating member below the graphite crucible, a crucible upper heat-insulating member above straight bodies of the graphite and quartz crucibles, a crucible outer heat-insulating member outside the straight body of the graphite crucible, a crucible inner heat-insulating member inside the straight bodies of the graphite crucible and the quartz crucible, and a heat shielding member above a liquid surface of the raw material melt, the graphite crucible and the quartz crucible being movable upward and downward in a space enclosed with the crucible upper heat-insulating, crucible outer heat-insulating, and crucible inner heat-insulating members.Type: ApplicationFiled: August 26, 2013Publication date: August 27, 2015Inventors: Ryoji Hoshi, Kosei Sugawara
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Publication number: 20150020728Abstract: The present invention provides a method for manufacturing a silicon single crystal wafer, wherein, under a growth condition that V/G?1.05×(V/G)crt is achieved where V is a growth rate in growth of the silicon single crystal ingot, G is a temperature gradient near a crystal growth interface, and (V/G)crt is a value of V/G when a dominant point defect changes from a vacancy to interstitial Si, a silicon single crystal ingot having oxygen concentration of 7×1017 atoms/cm3 (ASTM'79) or less is grown, and a silicon single crystal wafer which includes a region where the vacancy is dominant and in which FPDs are not detected by preferential etching is manufactured from the grown silicon single crystal ingot. As a result, there is provided the method that enables manufacturing a low-oxygen concentration silicon single crystal wafer that can be preferably used for a power device with good productivity at a low cost.Type: ApplicationFiled: February 15, 2013Publication date: January 22, 2015Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Ryoji Hoshi, Hiroyuki Kamada, Kosei Sugawara
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Patent number: 8885915Abstract: 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: GrantFiled: April 28, 2011Date of Patent: November 11, 2014Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Kosei Sugawara, Masahiko Urano, Ryoji Hoshi
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Patent number: 8858706Abstract: A single-crystal manufacturing apparatus according to the Czochralski method, including: a crucible that contains a raw material; a main chamber configured to accommodate a heater for heating and melting the raw material; and a pulling chamber configured to pull and accommodate a grown single crystal, the pulling chamber being continuously provided above the main chamber; an inner shield provided between the heater and the main chamber and for insulating heat radiated from the heater, and a supporting member for supporting the inner shield from below. The inner shield is supported at three or more supporting points contacting the supporting member, and a lower end of the inner shield except at the supporting points does not contact the supporting member.Type: GrantFiled: November 9, 2010Date of Patent: October 14, 2014Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Toshiro Shimada, Kosei Sugawara
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Publication number: 20130323153Abstract: The present invention provides a silicon single crystal wafer sliced out from a silicon single crystal ingot grown by a Czochralski method, wherein the silicon single crystal wafer is sliced out from the silicon single crystal ingot having oxygen concentration of 8×1017 atoms/cm3 (ASTM' 79) or less and includes of a defect region where neither FPDs nor LEPs are detected by preferential etching but LSTDs are detected by an infrared scattering method. As a result, the wafer having the low oxygen concentration can be provided at low cost without causing a breakdown voltage failure or a leak failure at the time of fabricating a device.Type: ApplicationFiled: February 15, 2012Publication date: December 5, 2013Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Ryoji Hoshi, Suguru Matsumoto, Hiroyuki Kamada, Kosei Sugawara
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Publication number: 20130247815Abstract: A single crystal production apparatus including: a crucible containing raw material melt; a heater heating the raw material melt; a cooling cylinder that is cooled forcedly by a cooling medium; and a cooling chamber that houses the crucible, the heater, and the cooling cylinder, wherein a heat-shielding member having a heat insulating material is disposed, near an interface between the raw material melt and a single crystal being pulled, in such a way as to surround the single crystal being pulled, the cooling cylinder is disposed above the heat-shielding member in such a way as to surround the single crystal being pulled, and a cooling-cylinder-peripheral heat insulator is disposed with a gap provided between the cooling-cylinder-peripheral heat insulator and a periphery of the cooling cylinder in such a way as to surround the cooling cylinder.Type: ApplicationFiled: January 6, 2012Publication date: September 26, 2013Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Kosei Sugawara, Suguru Matsumoto, Toshiro Shimada, Ryoji Hoshi
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Publication number: 20130058540Abstract: 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: ApplicationFiled: April 28, 2011Publication date: March 7, 2013Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Kosei Sugawara, Masahiko Urano, Ryoji Hoshi
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Publication number: 20120192786Abstract: A single-crystal manufacturing apparatus according to the Czochralski method, including: a crucible that contains a raw material; a main chamber configured to accommodate a heater for heating and melting the raw material; and a pulling chamber configured to pull and accommodate a grown single crystal, the pulling chamber being continuously provided above the main chamber; an inner shield provided between the heater and the main chamber and for insulating heat radiated from the heater, and a supporting member for supporting the inner shield from below. The inner shield is supported at three or more supporting points contacting the supporting member, and a lower end of the inner shield except at the supporting points does not contact the supporting member.Type: ApplicationFiled: November 9, 2010Publication date: August 2, 2012Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Toshiro Shimada, Kosei Sugawara
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Patent number: 8083852Abstract: 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: GrantFiled: March 24, 2009Date of Patent: December 27, 2011Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Kosei Sugawara, Ryoji Hoshi, Masanori Takazawa, Yuuichi Miyahara, Atsushi Iwasaki
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Publication number: 20110017125Abstract: 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: ApplicationFiled: March 24, 2009Publication date: January 27, 2011Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Kosei Sugawara, Ryoji Hoshi, Masanori Takazawa, Yuuichi Miyahara, Atsushi Iwasaki