Patents by Inventor Isao Yokokawa
Isao Yokokawa 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: 20230268222Abstract: A method for manufacturing an SOI wafer including: a step of forming a silicon oxide film by thermal oxidation on an entire surface of a base wafer containing a dopant; and bonding a main surface of a bond wafer to a first main surface via the silicon oxide film, wherein, prior to the thermal oxidation step, a step of forming a CVD insulator film on a second main surface; and a step of forming, on the first main surface, a barrier silicon layer containing a dopant at a lower concentration than a dopant concentration of the base wafer, and in the thermal oxidation step, the barrier silicon layer is thermally oxidized to produce a barrier silicon oxide film, and in the bonding step, the bond wafer is bonded to the base wafer via the barrier silicon oxide film as a part of the silicon oxide film.Type: ApplicationFiled: July 27, 2021Publication date: August 24, 2023Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventor: Isao YOKOKAWA
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Publication number: 20230154761Abstract: A method for manufacturing an SOI wafer including a step of performing an adjustment to a film thickness of an SOI layer of the SOI wafer by wet etching. In the step of performing the adjustment to the film thickness of the SOI layer, a first etching step of etching a surface of the SOI layer using an SC1 solution; and a second etching step of etching the surface of the SOI layer by bringing the SOI layer into contact with ozone water to form an oxide film on the surface of the SOI layer and then bringing the formed oxide film into contact with an HF-containing aqueous solution to remove the oxide film, are performed in combination. The etchings are performed such that a removal amount of the SOI layer in the first etching step is smaller than that in the second etching step.Type: ApplicationFiled: April 14, 2021Publication date: May 18, 2023Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Hiroji AGA, Isao YOKOKAWA
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Patent number: 10886163Abstract: A bonded wafer including an ion implantation step using a batch processing ion implanter, wherein the ion implantation step is performed by irradiating a bond wafer with a light element ion beam without forming an insulator film on the bond wafer surface or through an insulator film having a thickness of 50 nm or less formed on the bond wafer surface at an implantation angle inclined from a crystal axis of the bond wafer; and the bond wafer surface is irradiated with the center of the light element ion beam shining at a position on the bond wafer surface shifted from the center of the bond wafer parallel to the center of a rotor by a predetermined amount providing a bonded wafer to prevent degradation of the radial uniformity of ion implantation depth and manufacture a bonded wafer with excellent radial uniformity of thickness of a thin film after delamination.Type: GrantFiled: February 27, 2018Date of Patent: January 5, 2021Assignee: SHIN-ETSU HANDOTAI CO., LTD.Inventor: Isao Yokokawa
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Patent number: 10763157Abstract: A method for manufacturing an SOI wafer, including steps of: bonding a bond wafer and a base wafer each composed of a silicon wafer at room temperature with a silicon oxide film interposed therebetween; a thinning the bond wafer; and before the bonding step, cleaning the wafers with a hydrophilic cleaning liquid and drying the cleaned wafers by suction drying or spin drying. After the drying step is ended and before the bonding step is started, the wafers are stored until a state where a bonding speed at which the bonding step is to be performed is 20 mm/second or less. The bonding is performed with the bonding speed of 20 mm/second or less. This provides a method for manufacturing an SOI wafer by which an SOI wafer can be manufactured while generation of outer-peripheral micro voids is suppressed in a simple manner.Type: GrantFiled: November 27, 2017Date of Patent: September 1, 2020Assignee: SHIN-ETSU HANDOTAI CO., LTD.Inventor: Isao Yokokawa
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Publication number: 20200203217Abstract: A bonded wafer including an ion implantation step using a batch processing ion implanter, wherein the ion implantation step is performed by irradiating a bond wafer with a light element ion beam without forming an insulator film on the bond wafer surface or through an insulator film having a thickness of 50 nm or less formed on the bond wafer surface at an implantation angle inclined from a crystal axis of the bond wafer; and the bond wafer surface is irradiated with the center of the light element ion beam shining at a position on the bond wafer surface shifted from the center of the bond wafer parallel to the center of a rotor by a predetermined amount providing a bonded wafer to prevent degradation of the radial uniformity of ion implantation depth and manufacture a bonded wafer with excellent radial uniformity of thickness of a thin film after delamination.Type: ApplicationFiled: February 27, 2018Publication date: June 25, 2020Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventor: Isao YOKOKAWA
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Publication number: 20190295883Abstract: A method for manufacturing an SOI wafer, including steps of: bonding a bond wafer and a base wafer each composed of a silicon wafer at room temperature with a silicon oxide film interposed therebetween; a thinning the bond wafer; and before the bonding step, cleaning the wafers with a hydrophilic cleaning liquid and drying the cleaned wafers by suction drying or spin drying. After the drying step is ended and before the bonding step is started, the wafers are stored until a state where a bonding speed at which the bonding step is to be performed is 20 mm/second or less. The bonding is performed with the bonding speed of 20 mm/second or less. This provides a method for manufacturing an SOI wafer by which an SOI wafer can be manufactured while generation of outer-peripheral micro voids is suppressed in a simple manner.Type: ApplicationFiled: November 27, 2017Publication date: September 26, 2019Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventor: Isao YOKOKAWA
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Patent number: 10347525Abstract: A method for producing a bonded SOI wafer, by ion implantation delamination to fabricate a bonded SOI wafer having a BOX layer and a SOI layer on a base wafer. After performing flattening heat treatment in an argon gas-containing atmosphere, sacrificial oxidation treatment adjusts the film thickness of the SOI layer, wherein the film thickness of the BOX layer is 500 nm or more. A sacrificial oxide film is formed so the relationship between the film thickness of the SOI layer on the sacrificial oxidation treatment is performed. The film thickness of the sacrificial oxide film formed by the sacrificial oxidation treatment satisfies 0.9d>t>0.45d. A method for producing a bonded SOI wafer can prevent the generation of particles from the outermost peripheral part, which is the form of an overhang by flattening heat treatment, of a SOI layer in the production of a bonded SOI wafer.Type: GrantFiled: August 29, 2016Date of Patent: July 9, 2019Assignee: SHIN-ETSU HANDOTAI CO., LTD.Inventor: Isao Yokokawa
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Publication number: 20190074213Abstract: A method for producing a bonded SOI wafer, by ion implantation delamination to fabricate a bonded SOI wafer having a BOX layer and a SOI layer on a base wafer. After performing flattening heat treatment in an argon gas-containing atmosphere, sacrificial oxidation treatment adjusts the film thickness of the SOI layer, wherein the film thickness of the BOX layer is 500 nm or more. A sacrificial oxide film is formed so the relationship between the film thickness of the SOI layer on the sacrificial oxidation treatment is performed. The film thickness of the sacrificial oxide film formed by the sacrificial oxidation treatment satisfies 0.9d>t>0.45d. A method for producing a bonded SOI wafer can prevent the generation of particles from the outermost peripheral part, which is the form of an overhang by flattening heat treatment, of a SOI layer in the production of a bonded SOI wafer.Type: ApplicationFiled: August 29, 2016Publication date: March 7, 2019Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventor: Isao YOKOKAWA
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Patent number: 10204824Abstract: A method for producing a SOI wafer that includes implanting at least one type of gas ion selected from a hydrogen ion and a rare gas ion from a surface of a bond wafer formed of a silicon single crystal to form an ion implanted layer, bonding the ion-implanted surface of the bond wafer to a surface of a base wafer formed of a silicon single crystal through a silicon oxide film formed on the base wafer surface, delaminating the bond wafer at the ion implanted layer by performing delamination heat treatment to fabricate a SOI wafer having a buried oxide film layer and a SOI layer on the base wafer, and performing flattening heat treatment on the SOI wafer in an atmosphere containing argon gas.Type: GrantFiled: March 8, 2016Date of Patent: February 12, 2019Assignee: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Isao Yokokawa, Hiroji Aga, Norihiro Kobayashi
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Publication number: 20180144975Abstract: A method for producing a SOI wafer that includes implanting at least one type of gas ion selected from a hydrogen ion and a rare gas ion from a surface of a bond wafer formed of a silicon single crystal to form an ion implanted layer, bonding the ion-implanted surface of the bond wafer to a surface of a base wafer formed of a silicon single crystal through a silicon oxide film formed on the base wafer surface, delaminating the bond wafer at the ion implanted layer by performing delamination heat treatment to fabricate a SOI wafer having a buried oxide film layer and a SOI layer on the base wafer, and performing flattening heat treatment on the SOI wafer in an atmosphere containing argon gas.Type: ApplicationFiled: March 8, 2016Publication date: May 24, 2018Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Isao YOKOKAWA, Hiroji AGA, Norihiro KOBAYASHI
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Patent number: 9865497Abstract: A method for manufacturing bonded wafer including: producing bonded wafer having thin-film on its base wafer by an ion implantation delamination method, and reducing film thickness of the thin-film, wherein the step of reducing the film thickness includes a stage of reducing the film thickness by sacrificial oxidation treatment or vapor phase etching, wherein the method for manufacturing bonded wafer further includes a cleaning step of cleaning the bonded wafer exposing the delamination surface just before the step of reducing the film thickness, wherein the cleaning step includes a stage of performing a wet cleaning by successively dipping the bonded wafer to plural of cleaning baths, and wherein the wet cleaning is performed without applying ultrasonic in each of the cleaning baths in the wet cleaning. The method enables to clean bonded wafer exposing delamination surface remaining damage of ion implantation using a cleaning line in a strict control level.Type: GrantFiled: August 22, 2014Date of Patent: January 9, 2018Assignee: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Isao Yokokawa, Hiroji Aga, Hiroshi Fujisawa
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Patent number: 9673086Abstract: A method of producing a bonded wafer in which wafers each having a cutout portion are used as a bond wafer and a base wafer, and either or both of settings of an ion implanter with which ions are implanted and conditions of the ion implantation are adjusted in the step of implanting the ions such that a cutout portion of either or both of the bond wafer and the base wafer after bonding is located at within a range of 0±30° or 180±30° from a position at which separation of the bond wafer begins in the step of separating the bond wafer. This method can inhibit the occurrence of large fault defect that may be generated on a surface of a thin film right after the separation, when a thin film such as an SOI layer is formed by the ion implantation separation method.Type: GrantFiled: July 15, 2014Date of Patent: June 6, 2017Assignee: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Isao Yokokawa, Masahiro Kato
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Publication number: 20160197008Abstract: A method for manufacturing bonded wafer including: producing bonded wafer having thin-film on its base wafer by an ion implantation delamination method, and reducing film thickness of the thin-film, wherein the step of reducing the film thickness includes a stage of reducing the film thickness by sacrificial oxidation treatment or vapor phase etching, wherein the method for manufacturing bonded wafer further includes a cleaning step of cleaning the bonded wafer exposing the delamination surface just before the step of reducing the film thickness, wherein the cleaning step includes a stage of performing a wet cleaning by successively dipping the bonded wafer to plural of cleaning baths, and wherein the wet cleaning is performed without applying ultrasonic in each of the cleaning baths in the wet cleaning. The method enables to clean bonded wafer exposing delamination surface remaining damage of ion implantation using a cleaning line in a strict control level.Type: ApplicationFiled: August 22, 2014Publication date: July 7, 2016Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Isao YOKOKAWA, Hiroji AGA, Hiroshi FUJISAWA
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Publication number: 20160197007Abstract: A method of producing a bonded wafer in which wafers each having a cutout portion are used as a bond wafer and a base wafer, and either or both of settings of an ion implanter with which ions are implanted and conditions of the ion implantation are adjusted in the step of implanting the ions such that a cutout portion of either or both of the bond wafer and the base wafer after bonding is located at within a range of 0±30° or 180±30° from a position at which separation of the bond wafer begins in the step of separating the bond wafer. This method can inhibit the occurrence of large fault defect that may be generated on a surface of a thin film right after the separation, when a thin film such as an SOI layer is formed by the ion implantation separation method.Type: ApplicationFiled: July 15, 2014Publication date: July 7, 2016Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Isao YOKOKAWA, Masahiro KATO
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Patent number: 9337080Abstract: The present invention is a method for manufacturing an SOI wafer, including: implanting one or more gas ion selected from a hydrogen ion and a rare gas ion into a bond wafer composed of a semiconductor single crystal substrate from a surface of the bond wafer to form an ion-implanted layer; bonding the surface from which the ion is implanted into the bond wafer and a surface of a base wafer through an oxide film; and then delaminating the bond wafer at the ion-implanted layer by performing a delamination heat treatment with a heat treatment furnace to form the SOI wafer, wherein after the delamination heat treatment, a temperature of the heat treatment furnace is decreased to 250° C. or less at temperature-decreasing rate of less than 3.0° C/min, and then the SOI wafer and the bond wafer after delamination are taken out from the heat treatment furnace.Type: GrantFiled: November 7, 2013Date of Patent: May 10, 2016Assignee: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Hiroji Aga, Isao Yokokawa, Toru Ishizuka
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Publication number: 20150340279Abstract: The present invention provides a method for manufacturing SOI wafer, wherein, after plasma treatment has been performed on at least one surface of a bonding interface of the bond wafer and a bonding interface of the base wafer, bonding is performed through the oxide film, and the bond wafer is delaminated at the ion implanted layer by the delamination heat treatment comprising a first heat treatment at 250° C. or less for 2 hours or more and a second heat treatment at 400° C. to 450° C. for 30 minutes or more. Thereby, the method of manufacturing the SOI wafer that is small in SOI layer film thickness range, is small in surface roughness of the SOI layer surface, is smooth in shape of a terrace part and has no defects such as voids, blisters and so forth in the SOI layer can be provided.Type: ApplicationFiled: December 10, 2013Publication date: November 26, 2015Applicant: Shin-Etsu Handotai Co., Ltd.Inventors: Norihiro KOBAYASHI, Isao YOKOKAWA, Hiroji AGA
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Publication number: 20150249035Abstract: The present invention is a method for manufacturing an SOI wafer, including: implanting one or more gas ion selected from a hydrogen ion and a rare gas ion into a bond wafer composed of a semiconductor single crystal substrate from a surface of the bond wafer to form an ion-implanted layer; bonding the surface from which the ion is implanted into the bond wafer and a surface of a base wafer through an oxide film; and then delaminating the bond wafer at the ion-implanted layer by performing a delamination heat treatment with a heat treatment furnace to form the SOI wafer, wherein after the delamination heat treatment, a temperature of the heat treatment furnace is decreased to 250° C. or less at temperature-decreasing rate of less than 3.0° C./min, and then the SOI wafer and the bond wafer after delamination are taken out from the heat treatment furnace.Type: ApplicationFiled: November 7, 2013Publication date: September 3, 2015Applicant: Shin-Etsu Handotai Co., Ltd.Inventors: Hiroji Aga, Isao Yokokawa, Toru Ishizuka
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Patent number: 9076840Abstract: According to the present invention, there is provided a method for manufacturing an SOI wafer having the step of performing a first sacrificial oxidation treatment on the aforementioned bonded SOI wafer in which the delamination has been performed after a first RTA treatment has been performed thereon and then performing a second sacrificial oxidation treatment thereon after a second RTA treatment has been performed thereon, wherein the first and second RTA treatments are performed under a hydrogen gas containing atmosphere and at a temperature of 1100° C. or more, wherein after a thermal oxide film has been formed on the aforementioned SOI layer front surface by performing only thermal oxidation by a batch type heat treating furnace at a temperature of 900° C. or more and 1000° C. or less in the first and second sacrificial oxidation treatments, a treatment for removing the thermal oxide film is performed.Type: GrantFiled: November 30, 2012Date of Patent: July 7, 2015Assignee: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Norihiro Kobayashi, Hiroji Aga, Isao Yokokawa, Toru Ishizuka, Masahiro Kato
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Patent number: 8987109Abstract: A method for manufacturing a bonded wafer includes: an ion implantation step of using a batch type ion implanter; a bonding step of bonding an ion implanted surface of a bond wafer to a surface of a base wafer directly or through an insulator film; and a delamination step of delaminating the bond wafer at an ion implanted layer, thereby manufacturing a bonded wafer having a thin film on the base wafer, wherein the ion implantation into the bond wafer carried out at the ion implantation step is divided into a plurality of processes, the bond wafer is rotated on its own axis a predetermined rotation angle after each ion implantation, and the next ion implantation is carried out at an arrangement position obtained by the rotation.Type: GrantFiled: April 25, 2012Date of Patent: March 24, 2015Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Hiroji Aga, Isao Yokokawa, Nobuhiko Noto
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Patent number: 8962352Abstract: A method for calculating a warpage of a bonded SOI wafer includes: assuming that the epitaxial growth SOI wafer is a silicon single crystal wafer having the same dopant concentration as dopant concentration of the bond wafer; calculating a warpage A that occurs at the time of performing the epitaxial growth relative to the assumed silicon single crystal wafer; calculating a warpage B caused due to a thickness of the BOX layer of the epitaxial growth SOI wafer; determining a measured value of a warpage of the base wafer before bonding as a warpage C; and calculating a sum of the warpages (A+B+C) as the warpage of the bonded SOI wafer.Type: GrantFiled: August 21, 2012Date of Patent: February 24, 2015Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Isao Yokokawa, Hiroji Aga, Yasushi Mizusawa