Patents by Inventor Tae Mochizuki
Tae Mochizuki 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: 11987903Abstract: Provided is an n-type GaN crystal, in which a donor impurity contained at the highest concentration is Ge, and which has a room-temperature resistivity of lower than 0.03 ?·cm and a (004) XRD rocking curve FWHM of less than 20 arcsec. The n-type GaN crystal has two main surfaces, each having an area of 2 cm2 or larger. One of the two main surfaces can have a Ga polarity and can be inclined at an angle of 0° to 10° with respect to a (0001) crystal plane. Further, the n-type GaN crystal can have a diameter of 20 mm or larger.Type: GrantFiled: February 16, 2021Date of Patent: May 21, 2024Assignee: MITSUBISHI CHEMICAL CORPORATIONInventors: Kenji Iso, Tatsuya Takahashi, Tae Mochizuki, Yuuki Enatsu
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Publication number: 20240105449Abstract: A conductive C-plane GaN substrate has a resistivity of 2×10?2 ?·cm or less or an n-type carrier concentration of 1×1018 cm?3 or more at room temperature. At least one virtual line segment with a length of 40 mm can be drawn at least on one main surface of the substrate. The line segment satisfies at least one of the following conditions (A1) and (B1): (A1) when an XRC of (004) reflection is measured at 1 mm intervals on the line segment, a maximum value of XRC-FWHMs across all measurement points is less than 30 arcsec; and (B1) when an XRC of the (004) reflection is measured at 1 mm intervals on the line segment, a difference between maximum and minimum values of XRC peak angles across all the measurement points is less than 0.2°.Type: ApplicationFiled: September 29, 2023Publication date: March 28, 2024Applicant: MITSUBISHI CHEMICAL CORPORATIONInventors: Yutaka MIKAWA, Hideo FUJISAWA, Tae MOCHIZUKI, Hideo NAMITA, Shinichiro KAWABATA
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Patent number: 11810782Abstract: A conductive C-plane GaN substrate has a resistivity of 2×10?2 ?·cm or less or an n-type carrier concentration of 1×1018 cm?3 or more at room temperature. At least one virtual line segment with a length of 40 mm can be drawn at least on one main surface of the substrate. The line segment satisfies at least one of the following conditions (A1) and (B1): (A1) when an XRC of (004) reflection is measured at 1 mm intervals on the line segment, a maximum value of XRC-FWHMs across all measurement points is less than 30 arcsec; and (B1) when an XRC of the (004) reflection is measured at 1 mm intervals on the line segment, a difference between maximum and minimum values of XRC peak angles across all the measurement points is less than 0.2°.Type: GrantFiled: December 9, 2020Date of Patent: November 7, 2023Assignee: MITSUBISHI CHEMICAL CORPORATIONInventors: Yutaka Mikawa, Hideo Fujisawa, Tae Mochizuki, Hideo Namita, Shinichiro Kawabata
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Publication number: 20230253461Abstract: An object is to provide a nonpolar or semipolar GaN substrate having improved size and crystal quality. A self-standing GaN substrate has an angle between the normal of the principal surface and an m-axis of 0 degrees or more and 20 degrees or less, wherein: the size of the projected image in a c-axis direction when the principal surface is vertically projected on an M-plane is 10 mm or more; and when an a-axis length is measured on an intersection line between the principal surface and an A-plane, a low distortion section with a section length of 6 mm or more and with an a-axis length variation within the section of 10.0×10?5 ? or less is observed.Type: ApplicationFiled: April 18, 2023Publication date: August 10, 2023Applicant: Mitsubishi Chemical CorporationInventors: Satoru NAGAO, Yusuke TSUKADA, azunori KAMADA, Shuichi KUBO, Hirotaka IKEDA, Kenji FUJITO, Hideo FUJISAWA, Yutaka MIKAWA, Tae MOCHIZUKI
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Patent number: 11664428Abstract: An object is to provide a nonpolar or semipolar GaN substrate having improved size and crystal quality. A self-standing GaN substrate has an angle between the normal of the principal surface and an m-axis of 0 degrees or more and 20 degrees or less, wherein: the size of the projected image in a c-axis direction when the principal surface is vertically projected on an M-plane is 10 mm or more; and when an a-axis length is measured on an intersection line between the principal surface and an A-plane, a low distortion section with a section length of 6 mm or more and with an a-axis length variation within the section of 10.0×10?5 ? or less is observed.Type: GrantFiled: April 23, 2021Date of Patent: May 30, 2023Assignee: Mitsubishi Chemical CorporationInventors: Satoru Nagao, Yusuke Tsukada, Kazunori Kamada, Shuichi Kubo, Hirotaka Ikeda, Kenji Fujito, Hideo Fujisawa, Yutaka Mikawa, Tae Mochizuki
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Patent number: 11591715Abstract: A GaN single crystal having a gallium polar surface which is a main surface on one side and a nitrogen polar surface which is a main surface on the opposite side, wherein on the gallium polar surface is found at least one square area, an outer periphery of which is constituted by four sides of 2 mm or more in length, and, when the at least one square area is divided into a plurality of sub-areas each of which is a 100 ?m×100 ?m square, pit-free areas account for 80% or more of the plurality of sub-areas.Type: GrantFiled: April 6, 2021Date of Patent: February 28, 2023Assignee: MITSUBISHI CHEMICAL CORPORATIONInventors: Hideo Fujisawa, Yutaka Mikawa, Shinichiro Kawabata, Hideo Namita, Tae Mochizuki
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Patent number: 11404268Abstract: A method for growing a GaN crystal suitable as a material of GaN substrates including C-plane GaN substrates includes: a first step of preparing a GaN seed having a nitrogen polar surface; a second step of arranging a pattern mask on the nitrogen polar surface of the GaN seed, the pattern mask being provided with a periodical opening pattern comprising linear openings and including intersections, the pattern mask being arranged such that longitudinal directions of at least part of the linear openings are within ±3° from a direction of an intersection line between the nitrogen polar surface and an M-plane; and a third step of ammonothermally growing a GaN crystal through the pattern mask such that a gap is formed between the GaN crystal and the pattern mask.Type: GrantFiled: June 10, 2020Date of Patent: August 2, 2022Assignee: MITSUBISHI CHEMICAL CORPORATIONInventors: Yutaka Mikawa, Hideo Fujisawa, Tae Mochizuki, Hideo Namita, Shinichiro Kawabata
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Publication number: 20210273058Abstract: An object is to provide a nonpolar or semipolar GaN substrate having improved size and crystal quality. A self-standing GaN substrate has an angle between the normal of the principal surface and an m-axis of 0 degrees or more and 20 degrees or less, wherein: the size of the projected image in a c-axis direction when the principal surface is vertically projected on an M-plane is 10 mm or more; and when an a-axis length is measured on an intersection line between the principal surface and an A-plane, a low distortion section with a section length of 6 mm or more and with an a-axis length variation within the section of 10.0×10?5 ? or less is observed.Type: ApplicationFiled: April 23, 2021Publication date: September 2, 2021Applicant: Mitsubishi Chemical CorporationInventors: Satoru NAGAO, Yusuke TSUKADA, Kazunori KAMADA, Shuichi KUBO, Hirotaka IKEDA, Kenji FUJITO, Hideo FUJISAWA, Yutaka MIKAWA, Tae MOCHIZUKI
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Publication number: 20210230770Abstract: A GaN single crystal having a gallium polar surface which is a main surface on one side and a nitrogen polar surface which is a main surface on the opposite side, wherein on the gallium polar surface is found at least one square area, an outer periphery of which is constituted by four sides of 2 mm or more in length, and, when the at least one square area is divided into a plurality of sub-areas each of which is a 100 ?m×100 ?m square, pit-free areas account for 80% or more of the plurality of sub-areas.Type: ApplicationFiled: April 6, 2021Publication date: July 29, 2021Applicant: MITSUBISHI CHEMICAL CORPORATIONInventors: Hideo FUJISAWA, Yutaka MIKAWA, Shinichiro KAWABATA, Hideo NAMITA, Tae MOCHIZUKI
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Patent number: 11038024Abstract: An object is to provide a nonpolar or semipolar GaN substrate having improved size and crystal quality. A self-standing GaN substrate has an angle between the normal of the principal surface and an m-axis of 0 degrees or more and 20 degrees or less, wherein: the size of the projected image in a c-axis direction when the principal surface is vertically projected on an M-plane is 10 mm or more; and when an a-axis length is measured on an intersection line between the principal surface and an A-plane, a low distortion section with a section length of 6 mm or more and with an a-axis length variation within the section of 10.0×10?5 ? or less is observed.Type: GrantFiled: June 18, 2019Date of Patent: June 15, 2021Assignee: Mitsubishi Chemical CorporationInventors: Satoru Nagao, Yusuke Tsukada, Kazunori Kamada, Shuichi Kubo, Hirotaka Ikeda, Kenji Fujito, Hideo Fujisawa, Yutaka Mikawa, Tae Mochizuki
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Patent number: 11031475Abstract: An object is to provide a nonpolar or semipolar GaN substrate having improved size and crystal quality. A self-standing GaN substrate has an angle between the normal of the principal surface and an m-axis of 0 degrees or more and 20 degrees or less, wherein: the size of the projected image in a c-axis direction when the principal surface is vertically projected on an M-plane is 10 mm or more; and when an a-axis length is measured on an intersection line between the principal surface and an A-plane, a low distortion section with a section length of 6 mm or more and with an a-axis length variation within the section of 10.0×10 ?5 ? or less is observed.Type: GrantFiled: September 18, 2019Date of Patent: June 8, 2021Assignee: Mitsubishi Chemical CorporationInventors: Satoru Nagao, Yusuke Tsukada, Kazunori Kamada, Shuichi Kubo, Hirotaka Ikeda, Kenji Fujito, Hideo Fujisawa, Yutaka Mikawa, Tae Mochizuki
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Publication number: 20210164127Abstract: Provided is an n-type GaN crystal, in which a donor impurity contained at the highest concentration is Ge, and which has a room-temperature resistivity of lower than 0.03 ?·cm and a (004) XRD rocking curve FWHM of less than 20 arcsec. The n-type GaN crystal has two main surfaces, each having an area of 2 cm2 or larger. One of the two main surfaces can have a Ga polarity and can be inclined at an angle of 0° to 10° with respect to a (0001) crystal plane. Further, the n-type GaN crystal can have a diameter of 20 mm or larger.Type: ApplicationFiled: February 16, 2021Publication date: June 3, 2021Applicant: MITSUBISHI CHEMICAL CORPORATIONInventors: Kenji ISO, Tatsuya TAKAHASHI, Tae MOCHIZUKI, Yuuki ENATSU
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Patent number: 11001940Abstract: A new GaN single crystal is provided. A GaN single crystal according to the present embodiment comprises a gallium polar surface which is a main surface on one side and a nitrogen polar surface which is a main surface on the opposite side, wherein on the gallium polar surface is found at least one square area, an outer periphery of which is constituted by four sides each with a length of 2 mm or more, and, when the at least one square are is divided into a plurality of sub-areas each of which is a square of 100 ?m×100 ?m, pit-free areas account for 80% or more of the sub-areas.Type: GrantFiled: November 20, 2018Date of Patent: May 11, 2021Assignee: MITSUBISHI CHEMICAL CORPORATIONInventors: Hideo Fujisawa, Yutaka Mikawa, Shinichiro Kawabata, Hideo Namita, Tae Mochizuki
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Publication number: 20210090886Abstract: A conductive C-plane GaN substrate has a resistivity of 2×10?2 ?·cm or less or an n-type carrier concentration of 1×1018 cm?3 or more at room temperature. At least one virtual line segment with a length of 40 mm can be drawn at least on one main surface of the substrate. The line segment satisfies at least one of the following conditions (A1) and (B1): (A1) when an XRC of (004) reflection is measured at 1 mm intervals on the line segment, a maximum value of XRC-FWHMs across all measurement points is less than 30 arcsec; and (B1) when an XRC of the (004) reflection is measured at 1 mm intervals on the line segment, a difference between maximum and minimum values of XRC peak angles across all the measurement points is less than 0.2°.Type: ApplicationFiled: December 9, 2020Publication date: March 25, 2021Applicant: MITSUBISHI CHEMICAL CORPORATIONInventors: Yutaka Mikawa, Hideo Fujisawa, Tae Mochizuki, Hideo Namita, Shinichiro Kawabata
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Patent number: 10903072Abstract: A conductive C-plane GaN substrate has a resistivity of 2×10?2 ?·cm or less or an n-type carrier concentration of 1×1018 cm?3 or more at room temperature. At least one virtual line segment with a length of 40 mm can be drawn at least on one main surface of the substrate. The line segment satisfies at least one of the following conditions (A1) and (B1): (A1) when an XRC of (004) reflection is measured at 1 mm intervals on the line segment, a maximum value of XRC-FWHMs across all measurement points is less than 30 arcsec; and (B1) when an XRC of the (004) reflection is measured at 1 mm intervals on the line segment, a difference between maximum and minimum values of XRC peak angles across all the measurement points is less than 0.2°.Type: GrantFiled: July 15, 2020Date of Patent: January 26, 2021Assignee: MITSUBISHI CHEMICAL CORPORATIONInventors: Yutaka Mikawa, Hideo Fujisawa, Tae Mochizuki, Hideo Namita, Shinichiro Kawabata
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Publication number: 20200350163Abstract: A conductive C-plane GaN substrate has a resistivity of 2×10?2 ?·cm or less or an n-type carrier concentration of 1×1018 cm?3 or more at room temperature. At least one virtual line segment with a length of 40 mm can be drawn at least on one main surface of the substrate. The line segment satisfies at least one of the following conditions (A1) and (B1): (A1) when an XRC of (004) reflection is measured at 1 mm intervals on the line segment, a maximum value of XRC-FWHMs across all measurement points is less than 30 arcsec; and (B1) when an XRC of the (004) reflection is measured at 1 mm intervals on the line segment, a difference between maximum and minimum values of XRC peak angles across all the measurement points is less than 0.2°.Type: ApplicationFiled: July 15, 2020Publication date: November 5, 2020Applicant: MITSUBISHI CHEMICAL CORPORATIONInventors: Yutaka MIKAWA, Hideo FUJISAWA, Tae MOCHIZUKI, Hideo NAMITA, Shinichiro KAWABATA
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Patent number: 10796904Abstract: A conductive C-plane GaN substrate has a resistivity of 2×10?2 ?·cm or less or an n-type carrier concentration of 1×1018 cm?3 or more at room temperature. At least one virtual line segment with a length of 40 mm can be drawn at least on one main surface of the substrate. The line segment satisfies at least one of the following conditions (A1) and (B1): (A1) when an XRC of (004) reflection is measured at 1 mm intervals on the line segment, a maximum value of XRC-FWHMs across all measurement points is less than 30 arcsec; and (B1) when an XRC of the (004) reflection is measured at 1 mm intervals on the line segment, a difference between maximum and minimum values of XRC peak angles across all the measurement points is less than 0.2°.Type: GrantFiled: February 7, 2019Date of Patent: October 6, 2020Assignee: MITSUBISHI CHEMICAL CORPORATIONInventors: Yutaka Mikawa, Hideo Fujisawa, Tae Mochizuki, Hideo Namita, Shinichiro Kawabata
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Publication number: 20200303187Abstract: A method for growing a GaN crystal suitable as a material of GaN substrates including C-plane GaN substrates includes: a first step of preparing a GaN seed having a nitrogen polar surface; a second step of arranging a pattern mask on the nitrogen polar surface of the GaN seed, the pattern mask being provided with a periodical opening pattern comprising linear openings and including intersections, the pattern mask being arranged such that longitudinal directions of at least part of the linear openings are within ±3° from a direction of an intersection line between the nitrogen polar surface and an M-plane; and a third step of ammonothermally growing a GaN crystal through the pattern mask such that a gap is formed between the GaN crystal and the pattern mask.Type: ApplicationFiled: June 10, 2020Publication date: September 24, 2020Applicant: MITSUBISHI CHEMICAL CORPORATIONInventors: Yutaka MIKAWA, Hideo FUJISAWA, Tae MOCHIZUKI, Hideo NAMITA, Shinichiro KAWABATA
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Patent number: 10720326Abstract: A method for growing a GaN crystal suitable as a material of GaN substrates including C-plane GaN substrates includes: a first step of preparing a GaN seed having a nitrogen polar surface; a second step of arranging a pattern mask on the nitrogen polar surface of the GaN seed, the pattern mask being provided with a periodical opening pattern comprising linear openings and including intersections, the pattern mask being arranged such that longitudinal directions of at least part of the linear openings are within ±3° from a direction of an intersection line between the nitrogen polar surface and an M-plane; and a third step of ammonothermally growing a GaN crystal through the pattern mask such that a gap is formed between the GaN crystal and the pattern mask.Type: GrantFiled: February 7, 2019Date of Patent: July 21, 2020Assignee: MITSUBISHI CHEMICAL CORPORATIONInventors: Yutaka Mikawa, Hideo Fujisawa, Tae Mochizuki, Hideo Namita, Shinichiro Kawabata
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Publication number: 20200013860Abstract: An object is to provide a nonpolar or semipolar GaN substrate having improved size and crystal quality. A self-standing GaN substrate has an angle between the normal of the principal surface and an m-axis of 0 degrees or more and 20 degrees or less, wherein: the size of the projected image in a c-axis direction when the principal surface is vertically projected on an M-plane is 10 mm or more; and when an a-axis length is measured on an intersection line between the principal surface and an A-plane, a low distortion section with a section length of 6 mm or more and with an a-axis length variation within the section of 10.0×10?5 ? or less is observed.Type: ApplicationFiled: September 18, 2019Publication date: January 9, 2020Applicant: Mitsubishi Chemical CorporationInventors: Satoru NAGAO, Yusuke Tsukada, Kazunori Kamada, Shuichi Kubo, Hirotaka Ikeda, Kenji Fujito, Hideo Fujisawa, Yutaka Mikawa, Tae Mochizuki