Patents by Inventor Koji Tsunekawa
Koji Tsunekawa 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: 20080217289Abstract: A method of production of a magnetoresistance effect device is able to prevent or minimize a drop in the MR ratio and maintain the high performance of the magnetoresistance effect device even if forming an oxide layer as a surface-most layer constituting a protective layer by the oxidation process inevitably included in the process of production of microprocessing by dry etching performed in a vacuum. Two mask layers used for microprocessing are doubly piled up. This method of production of a magnetoresistivity effect device including a magnetic multilayer film including at least two magnetic layers includes a step of providing under a first mask material that is a nonorganic material a second mask material able to react with other atoms to form a conductive substance, and a device made according to the method.Type: ApplicationFiled: May 9, 2008Publication date: September 11, 2008Applicant: ANELVA CORPORATIONInventors: Hiroki Maehara, Tomoaki Osada, Mihoko Doi, Koji Tsunekawa, Naoki Watanabe
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Publication number: 20080202917Abstract: This application discloses a method and apparatus for manufacturing a magnetoresistive multilayer film having a structure where an antiferromagnetic layer, a pinned-magnetization layer, a nonmagnetic spacer layer and a free-magnetization layer are laminated on a substrate in this order. A film for the antiferromagnetic layer is deposited by sputtering as oxygen gas is added to a gas for the sputtering. A film for an extra layer interposed between the substrate and the antiferromagnetic layer is deposited by sputtering as oxygen gas is added to a gas for the sputtering. The film for the antiferromagnetic layer is deposited by sputtering as a gas mixture of argon and another gas of larger atomic number than argon is used.Type: ApplicationFiled: April 29, 2008Publication date: August 28, 2008Applicant: CANON ANELVA CORPORATIONInventors: David Djulianto DJAYAPRAWIRA, Koji TSUNEKAWA, Motonobu NAGAI
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Publication number: 20080180862Abstract: A magnetoresistance effect device including a multilayer structure having a pair of ferromagnetic layers and a barrier layer positioned between them, wherein at least one ferromagnetic layer has at least the part contacting the barrier layer made amorphous and the barrier layer is an MgO layer having a highly oriented texture structure.Type: ApplicationFiled: March 28, 2008Publication date: July 31, 2008Applicants: ANELVA CORPORATION, NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGYInventors: David D. DJAYAPRAWIRA, Koji TSUNEKAWA, Motonobu NAGAI, Hiroki MAEHARA, Shinji YAMAGATA, Naoki WATANABE, Shinji YUASA
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Publication number: 20080142156Abstract: This application discloses a method and apparatus for manufacturing a magnetoresistive multilayer film having a structure where an antiferromagnetic layer, a pinned-magnetization layer, a nonmagnetic spacer layer and a free-magnetization layer are laminated on a substrate in this order. A film for the antiferromagnetic layer is deposited by sputtering as oxygen gas is added to a gas for the sputtering. A film for an extra layer interposed between the substrate and the antiferromagnetic layer is deposited by sputtering as oxygen gas is added to a gas for the sputtering. The film for the antiferromagnetic layer is deposited by sputtering as a gas mixture of argon and another gas of larger atomic number than argon is used.Type: ApplicationFiled: November 30, 2007Publication date: June 19, 2008Applicant: CANON ANELVA CORPORATIONInventors: David Djulianto DJAYAPRAWIRA, Koji TSUNEKAWA, Motonobu NAGAI
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Publication number: 20080124454Abstract: A magnetoresistance effect device including a multilayer structure having a pair of ferromagnetic layers and a barrier layer positioned between them, wherein at least one ferromagnetic layer has at least the part contacting the barrier layer made amorphous and the barrier layer is an MgO layer having a highly oriented texture structure.Type: ApplicationFiled: January 3, 2008Publication date: May 29, 2008Applicants: ANELVA CORPORATION, NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGYInventors: David D. Djayaprawira, Koji Tsunekawa, Motonobu Nagai, Hiroki Maehara, Shinji Yamagata, Naoki Watanabe, Shinji Yuasa
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Publication number: 20080055793Abstract: A magnetoresistance effect device including a multilayer structure having a pair of ferromagnetic layers and a barrier layer positioned between them, wherein at least one ferromagnetic layer has at least the part contacting the barrier layer made amorphous and the barrier layer is an MgO layer having a highly oriented texture structure.Type: ApplicationFiled: October 23, 2007Publication date: March 6, 2008Applicants: ANELVA CORPORATION, NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGYInventors: David Djayaprawira, Koji Tsunekawa, Motonobu Nagai, Hiroki Maehara, Shinji Yamagata, Naoki Watanabe, Shinji Yuasa
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Publication number: 20070169699Abstract: This application discloses a method and apparatus for manufacturing a magnetoresistive multilayer film having a structure where an antiferromagnetic layer, a pinned-magnetization layer, a nonmagnetic spacer layer and a free-magnetization layer are laminated on a substrate in this order. A film for the antiferromagnetic layer is deposited by sputtering as oxygen gas is added to a gas for the sputtering. A film for an extra layer interposed between the substrate and the antiferromagnetic layer is deposited by sputtering as oxygen gas is added to a gas for the sputtering. The film for the antiferromagnetic layer is deposited by sputtering as a gas mixture of argon and another gas of larger atomic number than argon is used.Type: ApplicationFiled: March 20, 2007Publication date: July 26, 2007Applicant: CANON ANELVA CORPORATIONInventors: David Djayaprawira, Koji Tsunekawa, Motonobu Nagai
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Publication number: 20070070553Abstract: A magnetoresistance effect device has a fixed ferromagnetism layer, a free ferromagnetism layer, and a barrier layer sandwiched by these ferromagnetic layers. It is constituted so that CoFeB whose amount of addition of boron B (b: atomic %) is 21%?b?23% may be used for the free ferromagnetism layer. In the magnetic resistance effect element, a magnetostrictive constant does not change steeply near the magnetostrictive constant zero. A MR ratio is maintained to be high.Type: ApplicationFiled: September 27, 2006Publication date: March 29, 2007Applicant: Canon ANELVA CorporationInventors: Koji Tsunekawa, David Djayaprawira
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Publication number: 20060056115Abstract: A magnetoresistance effect device including a multilayer structure having a pair of ferromagnetic layers and a barrier layer positioned between them, wherein at least one ferromagnetic layer has at least the part contacting the barrier layer made amorphous and the barrier layer is an MgO layer having a highly oriented texture structure.Type: ApplicationFiled: September 7, 2005Publication date: March 16, 2006Applicants: ANELVA Corporation, NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGYInventors: David Djayaprawira, Koji Tsunekawa, Motonobu Nagai, Hiroki Maehara, Shinji Yamagata, Naoki Watanabe, Shinji Yuasa
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Publication number: 20060038246Abstract: A method of production of a magnetoresistance effect device is able to prevent or minimize a drop in the MR ratio and maintain the high performance of the magnetoresistance effect device even if forming an oxide layer as a surface-most layer constituting a protective layer by the oxidation process inevitably included in the process of production of microprocessing by dry etching performed in a vacuum. Two mask layers used for microprocessing are doubly piled up. This method of production of a magnetoresistivity effect device including a magnetic multilayer film including at least two magnetic layers includes a step of providing under a first mask material that is a nonorganic material a second mask material able to react with other atoms to form a conductive substance, and a device made according to the method.Type: ApplicationFiled: August 11, 2005Publication date: February 23, 2006Applicant: ANELVA CORPORATIONInventors: Hiroki Maehara, Tomoaki Osada, Mihoko Doi, Koji Tsunekawa, Naoki Watanabe
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Publication number: 20050083612Abstract: This application discloses a method and apparatus for manufacturing a magnetoresistive multilayer film having a structure where an antiferromagnetic layer, a pinned-magnetization layer, a nonmagnetic spacer layer and a free-magnetization layer are laminated on a substrate in this order. A film for the antiferromagnetic layer is deposited by sputtering as oxygen gas is added to a gas for the sputtering. A film for an extra layer interposed between the substrate and the antiferromagnetic layer is deposited by sputtering as oxygen gas is added to a gas for the sputtering. The film for the antiferromagnetic layer is deposited by sputtering as a gas mixture of argon and another gas of larger atomic number than argon is used.Type: ApplicationFiled: October 18, 2004Publication date: April 21, 2005Inventors: David Djayaprawira, Koji Tsunekawa, Motonobu Nagai
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Publication number: 20050068695Abstract: This application discloses a magnetoresistive multilayer film having the structure where an antiferromagnetic layer, a pinned-magnetization layer, a non-magnetic spacer layer and a free-magnetization layer are laminated in this order. An opposite-side layer is provided on the side of the antiferromagnetic layer opposite to the pinned-magnetization layer. The opposite-side layer has components of nickel and chromium. Atomic numeral ratio of chromium in the opposite-side layer is preferrably not less than 41% and not more than 70%, more preferrally not less than 43%.Type: ApplicationFiled: September 24, 2004Publication date: March 31, 2005Inventors: David Djayaprawira, Koji Tsunekawa, Motonobu Nagai
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Patent number: 6720036Abstract: A production method of the present invention is a method of producing a spin valve type giant magnetoresistive thin film. In this production method, a buffer layer, an antiferromagnetic layer, a fixed magnetization layer, a nonmagnetic conductive layer, a free magnetization layer, and a protective layer are consecutively stacked on a substrate. Furter, plasma treatment is performed on predetermined stacked interfaces in the spin valve type giant magnetoresistive thin film to reduce the interlayer coupling magnetic field acting between the fixed magnetization layer and the free magnetization layer and to obtain a high MR ratio. The above production method can achieve both of the high MR ratio and low interlayer coupling magnetic field (Hin) in the thin film produced.Type: GrantFiled: September 10, 2002Date of Patent: April 13, 2004Assignee: Anelva CorporationInventors: Koji Tsunekawa, Daisuke Nakajima
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Patent number: 6641703Abstract: A magnetic multi-layer film manufacturing apparatus has a transferring chamber, a plurality of film-depositing chambers, and a robotic transferring device. Each film-depositing chamber has a rotatable substrate holder, a plurality of targets positioned at an incline on an opposing interior surface from the substrate holder, and a double layer rotating shutter mechanism and is controllable to deposit at least one layer of a magnetic multi-layer film structure. Magnetic multi-layer film structures are formed by depositing a plurality of magnetic films divided into a plurality of groups, each one of the plurality of groups deposited in an associated one of the plurality of film-depositing chambers continuously in a laminated state. A first division between successive groups of magnetic films is between a metal oxide film and a magnetic layer continuous therewith and a second division is between an antiferromagnetic layer and a magnetic layer continuous therewith.Type: GrantFiled: November 30, 2001Date of Patent: November 4, 2003Assignee: Anelva CorporationInventors: Shuji Nomura, Ayumu Miyoshi, Koji Tsunekawa
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Patent number: 6610373Abstract: In a device for forming magnetic film which deposits magnetic material on a substrate 12, a device is provided which, before the magnetic film is formed in a magnetic film-forming chamber 11, cleans one or both of the film-forming face and reverse face of the substrate 12 in a cleaning processing chamber 13. The cleaning mechanism carries out cleaning by placing a substrate on a horseshoe-shaped insulator substrate-holding part 51 which moves up and down, and emission of gas from the reverse face of the substrate and the like is brought about by generating Ar plasma between the upper periphery of the substrate, the substrate and a lower insulator 61 of the substrate.Type: GrantFiled: October 10, 2001Date of Patent: August 26, 2003Assignee: Anelva CorporationInventors: Daisuke Nakajima, Koji Tsunekawa, Naoki Watanabe
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Publication number: 20030049389Abstract: A production method of the present invention is a method of producing a spin valve type giant magnetoresistive thin film. In this production method, a buffer layer, an antiferromagnetic layer, a fixed magnetization layer, a nonmagnetic conductive layer, a free magnetization layer, and a protective layer are consecutively stacked on a substrate. Furter, plasma treatment is performed on predetermined stacked interfaces in the spin valve type giant magnetoresistive thin film to reduce the interlayer coupling magnetic field acting between the fixed magnetization layer and the free magnetization layer and to obtain a high MR ratio. The above production method can achieve both of the high MR ratio and low interlayer coupling magnetic field (Hin) in the thin film produced.Type: ApplicationFiled: September 10, 2002Publication date: March 13, 2003Applicant: Anelva CorporationInventors: Koji Tsunekawa, Daisuke Nakajima
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Publication number: 20020064595Abstract: A magnetic multi-layer film manufacturing apparatus has a transferring chamber, a plurality of film-depositing chambers, and a robotic transferring device. Each film-depositing chamber has a rotatable substrate holder, a plurality of targets positioned at an incline on an opposing interior surface from the substrate holder, and a double layer rotating shutter mechanism and is controllable to deposit at least one layer of a magnetic multi-layer film structure. Magnetic multi-layer film structures are formed by depositing a plurality of magnetic films divided into a plurality of groups, each one of the plurality of groups deposited in an associated one of the plurality of film-depositing chambers continuously in a laminated state. A first division between successive groups of magnetic films is between a metal oxide film and a magnetic layer continuous therewith and a second division is between an antiferromagnetic layer and a magnetic layer continuous therewith.Type: ApplicationFiled: November 30, 2001Publication date: May 30, 2002Inventors: Shuji Nomura, Ayumu Miyoshi, Koji Tsunekawa
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Publication number: 20020064594Abstract: In a device for forming magnetic film which deposits magnetic material on a substrate 12, a device is provided which, before the magnetic film is formed in a magnetic film-forming chamber 11, cleans one or both of the film-forming face and reverse face of the substrate 12 in a cleaning processing chamber 13. The cleaning mechanism carries out cleaning by placing a substrate on a horseshoe-shaped insulator substrate-holding part 51 which moves up and down, and emission of gas from the reverse face of the substrate and the like is brought about by generating Ar plasma between the upper periphery of the substrate, the substrate and a lower insulator 61 of the substrate.Type: ApplicationFiled: October 10, 2001Publication date: May 30, 2002Inventors: Daisuke Nakajima, Koji Tsunekawa, Naoki Watanabe