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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Patent number: 7521265Abstract: In a method for measuring an amount of strain of a bonded strained wafer, at least one strained layer is formed on a single crystal substrate. The bonded strained wafer is measured with respect to two asymmetric diffraction planes with diffraction plane indices (XYZ) and (?X?YZ) by an X-ray diffraction method, a reciprocal lattice space map is created from the measured data, and the amount of strain of the strained layer is calculated from the peak positions for the respective diffraction planes of the single crystal substrate and the strained layer appearing on the reciprocal lattice space map. Thereby, amounts of strain in the horizontal direction and in the vertical direction of the strained layer can be measured in a shorter time and more simply.Type: GrantFiled: January 11, 2005Date of Patent: April 21, 2009Assignee: Shin-Etsu Handotai Co., Ltd.Inventor: Isao Yokokawa
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Publication number: 20080315349Abstract: The present invention provides a method for manufacturing a bonded wafer prepared by bonding a base wafer and a bond wafer, comprising at least a step of etching an oxide film in a terrace region in an outer periphery of the bonded wafer wherein the oxide film in the terrace region is etched by spin-etching with holding and spinning the bonded wafer. Thereby, there is provided a method for manufacturing a bonded wafer in which an oxide film formed in a terrace region of a base wafer is efficiently etched without removing an oxide film on the back surface of the base wafer.Type: ApplicationFiled: November 2, 2005Publication date: December 25, 2008Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Tokio Takei, Sigeyuki Yoshizawa, Susumu Miyazaki, Isao Yokokawa, Nobuhiko Noto
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Publication number: 20080138959Abstract: The present invention is a method for producing a semiconductor wafer, comprising: at least epitaxially growing a Si1-XGeX layer (0<X?1) on a surface of a silicon single crystal wafer to be a bond wafer; implanting at least one kind of a hydrogen ion or a rare gas ion through the Si1-XGeX layer and thereby, forming an ion-implanted layer inside the bond wafer; closely contacting and bonding a surface of the Si1-XGeX layer and a surface of a base wafer through an insulator film; then performing a delamination treatment of performing delamination at the ion-implanted layer; performing a bonding heat treatment of binding the bonded surfaces at a temperature of, at least, more than or equal to a temperature when the delamination treatment is performed; and then removing a Si layer of a delaminated layer transferred to a side of the base wafer by the delamination.Type: ApplicationFiled: November 2, 2005Publication date: June 12, 2008Applicant: Shin-Etsu Handotai Co., Ltd.Inventors: Isao Yokokawa, Hiroji Aga, Kiyoshi Mitani
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Publication number: 20080003785Abstract: The present invention is a method for producing a semiconductor wafer, comprising at least steps of, epitaxially growing a Si1-XGeX layer (0<X<1) on an SOI wafer, forming a Si1-YGeY layer (0?Y<X) on the epitaxially grown Si1-XGeX layer, and then enriching Ge in the epitaxially grown Si1-XGeX layer by an oxidation heat treatment so that the Si1-XGeX layer becomes an enriched SiGe layer, wherein, at least, the oxidation heat treatment is initiated from 950° C. or less under an oxidizing atmosphere, and the oxidation is performed so that the formed Si1-YGeY layer remains during a temperature rise to 950° C. Thereby, there can be provided a method for producing a semiconductor wafer by which the lattice relaxation of the SiGe layer in an SGOI wafer can be sufficiently performed by a heat treatment for a short time and its production cost can be reduced.Type: ApplicationFiled: September 16, 2005Publication date: January 3, 2008Applicant: Shin-etsu Handotai Co., Ltd.Inventors: Isao Yokokawa, Nobuhiko Noto, Kiyoshi Mitani
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Patent number: 7315064Abstract: The present invention provides a bonded wafer, wherein at least a silicon single crystal layer is formed on a silicon single crystal wafer, the silicon single crystal layer has a crystal plane orientation of {110}, and the silicon single crystal wafer has a crystal plane orientation of {100}. The present invention also provides a method of producing a bonded wafer, wherein after at least a first silicon single crystal wafer having a crystal plane orientation of {110} and a second silicon single crystal wafer having a crystal plane orientation of {100} are bonded directly or bonded via an insulator film, the first silicon single crystal wafer is made into a thin film. Thereby, there can be provided a wafer possible to obtain a MIS device having good characteristics by utilizing a silicon single crystal wafer having the {110} plane.Type: GrantFiled: December 15, 2005Date of Patent: January 1, 2008Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Kiyoshi Mitani, Kiyoshi Demizu, Isao Yokokawa, Tadahiro Ohmi, Shigetoshi Sugawa
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Publication number: 20070287269Abstract: The present invention is a method for producing a semiconductor wafer, comprising at least steps of: epitaxially growing a SiGe layer on a surface of a silicon single crystal wafer that is to be a bond wafer; implanting at least one kind of hydrogen ion and rare gas ion through the SiGe layer, so that an ion implanted layer is formed inside the bond wafer; closely contacting and bonding a surface of the SiGe layer and a surface of a base wafer through an insulator film; then performing delamination at the ion implanted layer, removing a Si layer in a delaminated layer transferred to a side of the base wafer by the delamination, so that the SiGe layer is exposed; and then subjecting the exposed SiGe layer to a heat treatment for enriching Ge under an oxidizing atmosphere and/or a heat treatment for relaxing lattice strain under a non-oxidizing atmosphere.Type: ApplicationFiled: October 14, 2005Publication date: December 13, 2007Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Isao Yokokawa, Nobuhiko Noto
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Publication number: 20070166845Abstract: The present invention is a method for measuring an amount of strain of a bonded strained wafer in which at least one strained layer is formed on a single crystal substrate by a bonding method, wherein at least, the bonded strained wafer is measured with respect to two asymmetric diffraction planes with diffraction plane indices (XYZ) and (?X?YZ) by an X-ray diffraction method, a reciprocal lattice space map is created from the measured data, and the amount of strain of the strained layer is calculated from the peak positions for the respective diffraction planes of the single crystal substrate and the strained layer appearing on the reciprocal lattice space map. Thereby, there can be provided a method for measuring an amount of strain by which amounts of strain in the horizontal direction and in the vertical direction of the strained layer by an X-ray diffraction method in a bonded strained wafer can be measured in a shorter time and more simply.Type: ApplicationFiled: January 11, 2005Publication date: July 19, 2007Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventor: Isao Yokokawa
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Publication number: 20070023066Abstract: The present invention is a method for cleaning a multilayer substrate, comprising steps of forming a protective film on a surface of the SiGe layer of an outermost surface layer in the multilayer substrate and then cleaning the protective film with a cleaning liquid capable of etching the protective film so that the protective film remains, a method for bonding substrates, wherein an outermost surface layer of the multilayer substrate cleaned by the cleaning method and a surface of another substrate are bonded, and a method for producing a bonded wafer, comprising steps of, forming a Si1-XGex layer and a protective layer on a surface of a Si single crystal bond wafer in order, performing ion implantation through the protective layer thereby to form an ion implanted layer, cleaning the bond wafer, superposing closely a surface of the protective layer and a base wafer, then performing delamination at the ion implanted layer, forming a thermal oxide film on a surface of the delaminated layer transferred to the bType: ApplicationFiled: September 7, 2004Publication date: February 1, 2007Inventors: Isao Yokokawa, Kiyoshi Mitani
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Patent number: 7091107Abstract: There is disclosed a method of producing an SOI wafer in which an SOI layer is formed on a buried oxide film by, at least implanting at least one kind of ion of hydrogen ion and a rare gas ion into the surface portion of a bond wafer to form an ion-implanted layer, bonding the bond wafer and a base wafer to each other through an oxide film, and delaminating the resultant bonded wafer at the ion-implanted layer, wherein assuming that X [nm] represents the thickness of the buried oxide film and Y [nm] represents the thickness of the SOI layer in the SOI wafer immediately after delaminating at the ion-implanted layer, when the thickness X of the buried oxide film is X?100, in forming the ion-implanted layer, the ion implantation is carried out with the ion implantation conditions being set such that the sum X+Y of the thickness of the buried oxide film and the thickness of the SOI layer satisfies X+Y>1500?14X, after which the bonding process and the delaminating process are carried out and, thereafter, a thinType: GrantFiled: February 23, 2004Date of Patent: August 15, 2006Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Isao Yokokawa, Kiyoshi Mitani
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Patent number: 7084046Abstract: After completion of annealing for bonding of the base wafer 1 and bond wafer 2, the bond wafer 2 is thinned to a first thickness suitable for ion implantation, and boron is ion-implanted to thereby form a high-boron-concentration layer 10. A second thinning step based on selective etching is then carried out while using the high-boron-concentration layer 10 as an etch stop layer. This is successful in providing a method of fabricating an SOI wafer which is suppressed both in intra-wafer uniformity of the firm thickness and in inter-wafer uniformity of the film thickness even when a required level for the thickness of the SOI layer is extremely small.Type: GrantFiled: October 31, 2002Date of Patent: August 1, 2006Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Kiyoshi Mitani, Isao Yokokawa
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Patent number: 7052974Abstract: The present invention provides a bonded wafer, wherein at least a silicon single crystal layer is formed on a silicon single crystal wafer, the silicon single crystal layer has a crystal plane orientation of {110}, and the silicon single crystal wafer has a crystal plane orientation of {100}. The present invention also provides a method of producing a bonded wafer, wherein after at least a first silicon single crystal wafer having a crystal plane orientation of {110} and a second silicon single crystal wafer having a crystal plane orientation of {100} are bonded directly or bonded via an insulator film, the first silicon single crystal wafer is made into a thin film. Thereby, there can be provided a wafer possible to obtain a MIS device having good characteristics by utilizing a silicon single crystal wafer having the {110} plane.Type: GrantFiled: November 25, 2002Date of Patent: May 30, 2006Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Kiyoshi Mitani, Kiyoshi Demizu, Isao Yokokawa, Tadahiro Ohmi, Shigetoshi Sugawa
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Publication number: 20060099791Abstract: The present invention provides a bonded wafer, wherein at least a silicon single crystal layer is formed on a silicon single crystal wafer, the silicon single crystal layer has a crystal plane orientation of {110}, and the silicon single crystal wafer has a crystal plane orientation of {100}. The present invention also provides a method of producing a bonded wafer, wherein after at least a first silicon single crystal wafer having a crystal plane orientation of {110} and a second silicon single crystal wafer having a crystal plane orientation of {100} are bonded directly or bonded via an insulator film, the first silicon single crystal wafer is made into a thin film. Thereby, there can be provided a wafer possible to obtain a MIS device having good characteristics by utilizing a silicon single crystal wafer having the {110} plane.Type: ApplicationFiled: December 15, 2005Publication date: May 11, 2006Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Kiyoshi Mitani, Kiyoshi Demizu, Isao Yokokawa, Tadahiro Ohmi, Shigetoshi Sugawa
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Publication number: 20060051945Abstract: The present invention provides a method of producing an SOI wafer, comprising at least steps of forming an oxygen ion-implanted layer by implanting oxygen ions into a silicon wafer from one main surface thereof, subjecting the silicon wafer to oxide film-forming heat treatment to convert the oxygen ion-implanted layer into a buried oxide film, and thereby producing an SOI wafer having an SOI layer on the buried oxide film, wherein when the buried oxide film is formed in the silicon wafer, the buried oxide film is formed so that a thickness thereof is thicker than a thickness of the buried oxide film which the SOI wafer to be produced has, and thereafter the silicon wafer in which the thicker buried oxide film is formed is subjected to a heat treatment to reduce the thickness of the buried oxide film.Type: ApplicationFiled: February 13, 2004Publication date: March 9, 2006Applicant: SHIN-ETSU HANDOTAI CO,. LTD.Inventors: Isao Yokokawa, Hiroji Aga, Kiyotaka Takano, Kiyoshi Mitani
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Patent number: 6959854Abstract: There is provided a method for producing a bonded substrate comprising, at least, a process of joining two substrates and a process of subjecting the joined substrates to heat treatment to bond them firmly, wherein, at least, a process of cleaning for removing contaminants on the surface of the substrates is performed before joining the substrates, and then a process of drying the cleaned surface of the substrates is performed without using the water displacing method for the drying process, so that moisture is left on the substrates before joining to increase a joining strength after joining the substrates. Thereby, there can be provided a method for producing a bonded substrate wherein a joining strength of the joining interface of the substrates to be joined is improved, and thus the bonded substrate wherein there is no void failure and blister failure in the bonding interface of a bonded substrate after bonding heat treatment can be produced at high productivity and high yield.Type: GrantFiled: April 9, 2002Date of Patent: November 1, 2005Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Isao Yokokawa, Masatake Nakano, Kiyoshi Mitani
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Publication number: 20050118789Abstract: The present invention relates to a method of producing an SOI wafer in which an SOI layer is formed on a buried oxide film by forming an oxide film on a surface of at least one of a bond wafer and a base wafer, bonding the bond wafer to the base wafer through the formed oxide film, and making the bond wafer into a thin film, wherein after the oxide film is formed so that a total thickness of the oxide film formed on the surface of at least one of the bond wafer and the base wafer is thicker than a thickness of the buried oxide film that the SOI wafer to be produced has, the bond wafer is bonded to the base wafer through the formed oxide film, the bond wafer is made into a thin film to form an SOI layer, and thereafter, an obtained bonded wafer is subjected to heat treatment to reduce a thickness of the buried oxide film.Type: ApplicationFiled: December 25, 2003Publication date: June 2, 2005Applicant: SHIN-ETSU HANDOTAI CO.,LTDInventors: Hiroji Aga, Isao Yokokawa, Kiyotaka Takano, Kiyoshi Mitani
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Patent number: 6900113Abstract: The present invention provides a method for producing a bonded wafer comprising at least an ion implantation process where at least either hydrogen ions or rare gas ions are implanted into a first wafer from its surface to form a micro bubble layer (implanted layer) in the first wafer, a bonding process where the surface subjected to the ion implantation of the first wafer is bonded to a surface of a second wafer, and a delamination process where the first wafer is delaminated at the micro bubble layer, wherein the ion implantation process is performed in divided multiple steps, and a bonded wafer. Thus, there are provided a method for producing a bonded wafer, which is for reducing micro-voids generated in the ion implantation and delamination method and a bonded wafer free from micro-voids.Type: GrantFiled: May 29, 2001Date of Patent: May 31, 2005Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Masatake Nakano, Isao Yokokawa, Kiyoshi Mitani
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Publication number: 20050014346Abstract: After completion of annealing for bonding of the base wafer 1 and bond wafer 2, the bond wafer 2 is thinned to a first thickness suitable for ion implantation, and boron is ion-implanted to thereby form a high-boron-concentration layer 10. A second thinning step based on selective etching is then carried out while using the high-boron-concentration layer 10 as an etch stop layer. This is successful in providing a method of fabricating an SOI wafer which is suppressed both in intra-wafer uniformity of the firm thickness and in inter-wafer uniformity of the film thickness even when a required level for the thickness of the SOI layer is extremely small.Type: ApplicationFiled: October 31, 2002Publication date: January 20, 2005Inventors: Kiyoshi Mitani, Isao Yokokawa
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Publication number: 20050003648Abstract: The present invention provides a bonded wafer, wherein at least a silicon single crystal layer is formed on a silicon single crystal wafer, the silicon single crystal layer has a crystal plane orientation of {110}, and the silicon single crystal wafer has a crystal plane orientation of {100}. The present invention also provides a method of producing a bonded wafer, wherein after at least a first silicon single crystal wafer having a crystal plane orientation of {110} and a second silicon single crystal wafer having a crystal plane orientation of {100} are bonded directly or bonded via an insulator film, the first silicon single crystal wafer is made into a thin film. Thereby, there can be provided a wafer possible to obtain a MIS device having good characteristics by utilizing a silicon single crystal wafer having the {110} plane.Type: ApplicationFiled: November 25, 2002Publication date: January 6, 2005Inventors: Kiyoshi Mitani, Kiyoshi Demizu, Isao Yokokawa, Tadahiro Ohmi, Shigetoshi Sugawa
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Publication number: 20040166650Abstract: There is disclosed a method of producing an SOI wafer in which an SOI layer is formed on a buried oxide film by, at least implanting at least one kind of ion of hydrogen ion and a rare gas ion into the surface portion of a bond wafer to form an ion-implanted layer, bonding the bond wafer and a base wafer to each other through an oxide film, and delaminating the resultant bonded wafer at the ion-implanted layer, wherein assuming that X [nm] represents the thickness of the buried oxide film and Y [nm] represents the thickness of the SOI layer in the SOI wafer immediately after delaminating at the ion-implanted layer, when the thickness X of the buried oxide film is X≦100, in forming the ion-implanted layer, the ion implantation is carried out with the ion implantation conditions being set such that the sum X+Y of the thickness of the buried oxide film and the thickness of the SOI layer satisfies X+Y>1500−14X, after which the bonding process and the delaminating processType: ApplicationFiled: February 23, 2004Publication date: August 26, 2004Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Isao Yokokawa, Kiyoshi Mitani
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Publication number: 20040035525Abstract: There is provided a method for producing a bonded substrate comprising, at least, a process of joining two substrates and a process of subjecting the joined substrates to heat treatment to bond them firmly, wherein, at least, a process of cleaning for removing contaminants on the surface of the substrates is performed before joining the substrates, and then a process of drying the cleaned surface of the substrates is performed without using the water displacing method for the drying process, so that moisture is left on the substrates before joining to increase a joining strength after joining the substrates. Thereby, there can be provided a method for producing a bonded substrate wherein a joining strength of the joining interface of the substrates to be joined is improved, and thus the bonded substrate wherein there is no void failure and blister failure in the bonding interface of a bonded substrate after bonding heat treatment can be produced at high productivity and high yield.Type: ApplicationFiled: December 16, 2002Publication date: February 26, 2004Inventors: Isao Yokokawa, Masatake Nakano, Kiyoshi Mitani