Patents by Inventor Shuichi Inami
Shuichi Inami 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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Patent number: 9145620Abstract: A single crystal pulling apparatus comprises: a chamber; a crucible disposed within the chamber for containing a melt; a water-cooling means disposed within the chamber in such a manner as surrounding a single crystal pulled up from the melt in the crucible; water piping for feeding cooling water to and discharging the same from the water-cooling means; and supporting arms connected to the chamber for supporting the water-cooling means, wherein the supporting arms are disposed between the single crystal and the water piping. According to this configuration, the supporting arms can prevent the water piping from being damaged in the event of fall and collapse of the single crystal due to failure of the seed neck portion or in the event of rupture of the single crystal due to thermal stress, for instance.Type: GrantFiled: April 7, 2009Date of Patent: September 29, 2015Assignee: SUMCO CORPORATIONInventors: Shuichi Inami, Ken Hamada, Hiroaki Taguchi, Takuya Yotsui, Takashi Atami
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Patent number: 8978494Abstract: A whole determination area of a targeted wafer is concentrically divided in a radial direction, COP density is obtained in each divided determination segment, a maximum value of the COP density is set as COP densityRADIUSMAX, a minimum value of the COP density is set as COP densityRADIUSMIN, a value computed by “(COP densityRADIUSMAX?COP densityRADIUSMIN/COP densityRADIUSMAX” is compared to a predetermined set value, and a non-crystal-induced COP and a crystal-induced COP are distinguished from each other based on a clear criterion, thereby determining the COP generation factor. Therefore, a rejected wafer in which a determination of the crystal-induced COP is made despite being the non-crystal-induced COP can be relieved, so that a wafer production yield can be enhanced.Type: GrantFiled: September 4, 2013Date of Patent: March 17, 2015Assignee: Sumco CorporationInventor: Shuichi Inami
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Publication number: 20140005953Abstract: A whole determination area of a targeted wafer is concentrically divided in a radial direction, COP density is obtained in each divided determination segment, a maximum value of the COP density is set as COP densityRADIUSMAX, a minimum value of the COP density is set as COP densityRADIUSMIN, a value computed by “(COP densityRADIUSMAX-COP densityRADIUSMIN/COP densityRADIUSMAX” is compared to a predetermined set value, and a non-crystal-induced COP and a crystal-induced COP are distinguished from each other based on a clear criterion, thereby determining the COP generation factor. Therefore, a rejected wafer in which a determination of the crystal-induced COP is made despite being the non-crystal-induced COP can be relieved, so that a wafer production yield can be enhanced.Type: ApplicationFiled: September 4, 2013Publication date: January 2, 2014Applicant: SUMCO CORPORATIONInventor: Shuichi INAMI
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Patent number: 8549937Abstract: A whole determination area of a targeted wafer is concentrically divided in a radial direction, COP density is obtained in each divided determination segment, a maximum value of the COP density is set as COP densityRADIUSMAX, a minimum value of the COP density is set as COP densityRADIUSMIN, a value computed by “(COP densityRADIUSMAX-COP densityRADIUSMIN)/COP densityRADIUSMAX” is compared to a predetermined set value, and a non-crystal-induced COP and a crystal-induced COP are distinguished from each other based on a clear criterion, thereby determining the COP generation factor. Therefore, a rejected wafer in which a determination of the crystal-induced COP is made despite being the non-crystal-induced COP can be relieved, so that a wafer production yield can be enhanced.Type: GrantFiled: October 25, 2012Date of Patent: October 8, 2013Assignee: Sumco CorporationInventor: Shuichi Inami
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Publication number: 20130054152Abstract: A whole determination area of a targeted wafer is concentrically divided in a radial direction, COP density is obtained in each divided determination segment, a maximum value of the COP density is set as COP densityRADIUSMAX, a minimum value of the COP density is set as COP densityRADIUSMIN, a value computed by “(COP densityRADIUSMAX-COP densityRADIUSMIN)/COP densityRADIUSMAX” is compared to a predetermined set value, and a non-crystal-induced COP and a crystal-induced COP are distinguished from each other based on a clear criterion, thereby determining the COP generation factor. Therefore, a rejected wafer in which a determination of the crystal-induced COP is made despite being the non-crystal-induced COP can be relieved, so that a wafer production yield can be enhanced.Type: ApplicationFiled: October 25, 2012Publication date: February 28, 2013Inventor: Shuichi INAMI
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Patent number: 8316727Abstract: A whole determination area of a targeted wafer is concentrically divided in a radial direction, COP density is obtained in each divided determination segment, a maximum value of the COP density is set as COP densityRADIUSMAX, a minimum value of the COP density is set as COP densityRADIUSMIN, a value computed by “(COP densityRADIUSMAX?COP densityRADIUSMIN)/COP densityRADIUSMAX” is compared to a predetermined set value, and a non-crystal-induced COP and a crystal-induced COP are distinguished from each other based on a clear criterion, thereby determining the COP generation factor. Therefore, a rejected wafer in which a determination of the crystal-induced COP is made despite being the non-crystal-induced COP can be relieved, so that a wafer production yield can be enhanced.Type: GrantFiled: October 4, 2011Date of Patent: November 27, 2012Assignee: Sumco CorporationInventor: Shuichi Inami
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Patent number: 8173449Abstract: An evaluation area of an evaluation object wafer is concentrically divided in a radial direction, an upper limit value to the number of COPs is set in each divided evaluation segment, and an acceptance determination of the single-crystal silicon wafer is made using the upper limit value as a criterion. Thereby, a quantitative and objective COP evaluation can be made, and a proper determination is made based on a clear criterion. The evaluation method of the present invention can sufficiently deal with automation of the COP evaluation (inspection) and the higher-quality wafer in the near future, and the evaluation method can be widely applied to production of the single-crystal silicon wafer and production of a semiconductor device.Type: GrantFiled: May 22, 2007Date of Patent: May 8, 2012Assignee: Sumco CorporationInventor: Shuichi Inami
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Publication number: 20120029834Abstract: A whole determination area of a targeted wafer is concentrically divided in a radial direction, COP density is obtained in each divided determination segment, a maximum value of the COP density is set as COP densityRADIUSMAX, a minimum value of the COP density is set as COP densityRADIUSMIN, a value computed by “(COP densityRADIUSMAX?COP densityRADIUSMIN)/COP densityRADIUSMAX” is compared to a predetermined set value, and a non-crystal-induced COP and a crystal-induced COP are distinguished from each other based on a clear criterion, thereby determining the COP generation factor. Therefore, a rejected wafer in which a determination of the crystal-induced COP is made despite being the non-crystal-induced COP can be relieved, so that a wafer production yield can be enhanced.Type: ApplicationFiled: October 4, 2011Publication date: February 2, 2012Applicant: SUMCO CORPORATIONInventor: Shuichi INAMI
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Patent number: 8061225Abstract: A whole determination area of a targeted wafer is concentrically divided in a radial direction, COP density is obtained in each divided determination segment, a maximum value of the COP density is set as COP densityRADIUSMAX, a minimum value of the COP density is set as COP densityRADIUSMIN, a value computed by “(COP densityRADIUSMAX?COP densityRADIUSMIN)/COP densityRADIUSMAX” is compared to a predetermined set value, and a non-crystal-induced COP and a crystal-induced COP are distinguished from each other based on a clear criterion, thereby determining the COP generation factor. Therefore, a rejected wafer in which a determination of the crystal-induced COP is made despite being the non-crystal-induced COP can be relieved, so that a wafer production yield can be enhanced.Type: GrantFiled: May 22, 2007Date of Patent: November 22, 2011Assignee: Sumco CorporationInventor: Shuichi Inami
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Patent number: 7819972Abstract: In a method for growing a silicon single crystal, a silicon single crystal is grown by the Czochralski method to have an oxygen concentration of 12×1017 to 18×1017 atoms/cm3 on ASTM-F121 1979. A mixed gas of an inert gas and a gaseous substance containing hydrogen atoms is used as an atmospheric gas for growing the single crystal. A temperature of the silicon single crystal is controlled during the growth of the crystal such that the ratio Gc/Ge of an axial thermal gradient Gc at the central portion of the crystal between its melting point and its temperature of 1350° C. to an axial thermal gradient Ge at the periphery of the crystal between its melting point and its temperature of 1350° C. is 1.1 to 1.4. The axial thermal gradient Gc at the central portion of the crystal is 3.0 to 3.5° C./mm.Type: GrantFiled: February 17, 2006Date of Patent: October 26, 2010Assignee: Sumco CorporationInventors: Shuichi Inami, Nobumitsu Takase, Yasuhiro Kogure, Ken Hamada, Tsuyoshi Nakamura
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Publication number: 20100000318Abstract: A whole determination area of a targeted wafer is concentrically divided in a radial direction, COP density is obtained in each divided determination segment, a maximum value of the COP density is set as COP densityRADIUSMIN, a minimum value of the COP density is set as COP densityRADIUSMIN, a value computed by “(COP densityRADIUSMAX?COP densityRADIUSMIN)/COP densityRADIUSMAX” is compared to a predetermined set value, and a non-crystal-induced COP and a crystal-induced COP are distinguished from each other based on a clear criterion, thereby determining the COP generation factor. Therefore, a rejected wafer in which a determination of the crystal-induced COP is made despite being the non-crystal-induced COP can be relieved, so that a wafer production yield can be enhanced.Type: ApplicationFiled: May 22, 2007Publication date: January 7, 2010Inventor: Shuichi Inami
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Patent number: 7641734Abstract: A method of growing silicon single crystals with a [110] crystallographic axis orientation by the Czochralski method is provided according to which a silicon seed crystal doped with a high concentration of boron is used and an included angle of a conical part during shoulder section formation is maintained within a specified range. It is thereby possible to grow large-diameter and heavy-weight dislocation-free silicon single crystals with a diameter of 300 mm or more in a stable manner, without the fear of dropping the single crystal during pulling up. Therefore, the method can be properly utilized in producing silicon single crystals as semiconductor materials.Type: GrantFiled: April 2, 2008Date of Patent: January 5, 2010Assignee: Sumco CorporationInventor: Shuichi Inami
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Publication number: 20090249998Abstract: A single crystal pulling apparatus comprises: a chamber; a crucible disposed within the chamber for containing a melt; a water-cooling means disposed within the chamber in such a manner as surrounding a single crystal pulled up from the melt in the crucible; water piping for feeding cooling water to and discharging the same from the water-cooling means; and supporting arms connected to the chamber for supporting the water-cooling means, wherein the supporting arms are disposed between the single crystal and the water piping. According to this configuration, the supporting arms can prevent the water piping from being damaged in the event of fall and collapse of the single crystal due to failure of the seed neck portion or in the event of rupture of the single crystal due to thermal stress, for instance.Type: ApplicationFiled: April 7, 2009Publication date: October 8, 2009Inventors: Shuichi Inami, Ken Hamada, Hiroaki Taguchi, Takuya Yotsui, Takashi Atami
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Publication number: 20090197358Abstract: An evaluation area of an evaluation object wafer is concentrically divided in a radial direction, an upper limit value to the number of COPs is set in each divided evaluation segment, and an acceptance determination of the single-crystal silicon wafer is made using the upper limit value as a criterion. Thereby, a quantitative and objective COP evaluation can be made, and a proper determination is made based on a clear criterion. The evaluation method of the present invention can sufficiently deal with automation of the COP evaluation (inspection) and the higher-quality wafer in the near future, and the evaluation method can be widely applied to production of the single-crystal silicon wafer and production of a semiconductor device.Type: ApplicationFiled: May 22, 2007Publication date: August 6, 2009Inventor: Shuichi Inami
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Patent number: 7473314Abstract: A silicon single crystal is grown using the Czochralski method. During the crystal growth, a thermal stress is applied to at least a portion of the silicon single crystal. A gaseous substance containing hydrogen atoms is used as an atmospheric gas for growing the crystal.Type: GrantFiled: March 28, 2006Date of Patent: January 6, 2009Assignee: Sumco CorporationInventors: Shuichi Inami, Nobumitsu Takase, Yasuhiro Kogure, Ken Hamada, Tsuyoshi Nakamura
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Patent number: 7442251Abstract: This method for producing silicon single crystals includes: growing a silicon single crystal by the Czochralski method while cooling at least part of the silicon single crystal under growth with a cooling member which circumferentially surrounds the silicon single crystal and has an inner contour that is coaxial with a pull axis, wherein an ambient gas in which the silicon single crystal is grown includes a hydrogen-atom-containing substance in gaseous form. This silicon single crystal is produced by the above method.Type: GrantFiled: April 19, 2006Date of Patent: October 28, 2008Assignee: Sumco CorporationInventors: Shuichi Inami, Hiroki Murakami, Nobumitsu Takase, Ken Hamada, Tsuyoshi Nakamura
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Publication number: 20080245291Abstract: A method of growing silicon single crystals with a [110] crystallographic axis orientation by the Czochralski method is provided according to which a silicon seed crystal doped with a high concentration of boron is used and an included angle of a conical part during shoulder section formation is maintained within a specified range. It is thereby possible to grow large-diameter and heavy-weight dislocation-free silicon single crystals with a diameter of 300 mm or more in a stable manner, without the fear of dropping the single crystal during pulling up. Therefore, the method can be properly utilized in producing silicon single crystals as semiconductor materials.Type: ApplicationFiled: April 2, 2008Publication date: October 9, 2008Inventor: Shuichi Inami
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Publication number: 20080053370Abstract: An aspect of the invention provides a silicon single crystal production method in which a dislocation-free feature can easily be achieved to enhance crystal quality irrespective of a crystal orientation. In the silicon single crystal production method of the invention, by a Czochralski method, in dipping the seed crystal in the melt, a melt temperature is set to an optimum temperature at which the seed crystal is brought into contact with a melt surface, the melt temperature is lowered, the seed crystal is pulled up while a pulling rate of the seed crystal is increased, and the pulling rate is kept at a constant rate to form the neck portion at the time that a pulling diameter reaches a target neck diameter. The invention is suitable to the case in which a silicon single crystal having a crystal orientation <110> is pulled up using the seed crystal having the crystal orientation <110>.Type: ApplicationFiled: September 4, 2007Publication date: March 6, 2008Inventors: Shuichi Inami, Kuniharu Inoue, Manabu Moroishi, Tsuguya Fukagawa, Nobuhiro Kusaba
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Publication number: 20080053368Abstract: Exemplary embodiments of the invention provide a method for producing a low-resistivity silicon single crystal in which a silicon wafer having a crystal axis orientation [110] can be obtained and dislocations are sufficiently eliminated, and a method for producing a low-resistance silicon wafer having the crystal axis orientation [110] from the silicon single crystal obtained by the low-resistivity silicon single crystal production method. In the silicon single crystal production method of the invention which employs a Czochralski method, the silicon single crystal whose center axis is inclined by 0.6° to 100 relative to a-crystal axis [110] is grown by dipping a silicon seed crystal in a silicon melt. Boron as a dopant is added in the silicon melt so that a boron concentration ranges from 6.25×1017 to 2.5×1020 atoms/cm3, a center axis of the silicon seed crystal is inclined by 0.Type: ApplicationFiled: September 4, 2007Publication date: March 6, 2008Inventors: Shuichi Inami, Kuniharu Inoue, Manabu Moroishi, Tsuguya Fukagawa, Nobuhiro Kusaba
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Publication number: 20060283377Abstract: This method for producing silicon single crystals includes: growing a silicon single crystal by the Czochralski method while cooling at least part of the silicon single crystal under growth with a cooling member which circumferentially surrounds the silicon single crystal and has an inner contour that is coaxial with a pull axis, wherein an ambient gas in which the silicon single crystal is grown includes a hydrogen-atom-containing substance in gaseous form. This silicon single crystal is produced by the above method.Type: ApplicationFiled: April 19, 2006Publication date: December 21, 2006Applicant: SUMCO CORPORATIONInventors: Shuichi Inami, Hiroki Murakami, Nobumitsu Takase, Ken Hamada, Tsuyoshi Nakamura