Patents by Inventor Yousuke Isowaki
Yousuke Isowaki 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: 20140233135Abstract: According to one embodiment, a magnetoresistance effect element includes first and second shields, a stacked body and a hard bias unit. The stacked body includes first and second magnetic layers, an intermediate layer and a first Ru layer. A magnetization of the first magnetic layer is changeable. A magnetization of the second magnetic layer is changeable. The intermediate layer is nonmagnetic. The first Ru layer is provided between the first shield and the first magnetic layer. A thickness of the first Ru layer is not less than 1.5 nanometers and not more than 2.5 nanometers. The hard bias unit is provided between the first shield and the second shield. A first direction from the first shield toward the second shield intersects a second direction from the stacked body toward the hard bias unit.Type: ApplicationFiled: February 18, 2014Publication date: August 21, 2014Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Susumu HASHIMOTO, Masayuki TAKAGISHI, Shuichi MURAKAMI, Yousuke ISOWAKI, Naoki HASE, Hitoshi IWASAKI
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Publication number: 20140211338Abstract: A magnetic head according to an embodiment includes a first magnetic shield and a second magnetic shield that are opposed to each other, and a magnetoresistive film arranged between the first magnetic shield and the second magnetic shield, and including a first magnetic layer including a first metal layer that contains 90 at. % or more of Fe and a first Heusler alloy layer, a second magnetic layer arranged on a side of the first Heusler alloy layer opposite from the first magnetic layer, and an intermediate layer arranged between the first Heusler alloy layer and the second magnetic layer.Type: ApplicationFiled: January 27, 2014Publication date: July 31, 2014Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Hitoshi IWASAKI, Shuichi MURAKAMI, Masayuki TAKAGISHI, Susumu HASHIMOTO, Yousuke ISOWAKI, Naoki HASE, Masaki KADO
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Patent number: 8748017Abstract: According to one embodiment, a bit patterned medium includes a substrate, and a magnetic recording layer disposed above the substrate and including patterns of protrusions. Each of the protrusions contains a plurality of crystal grains. An average distance between the crystal grains is 0.5 to 3.0 nm in each of the protrusions. The protrusions include first protrusions each having a length of 1 ?m or more in a radial direction of the medium and second protrusions each having a length in the radial direction shorter than the length of the first protrusion in the radial direction. Each of the first protrusions has a nucleation field Hn for magnetization reversal and a coercive force Hc satisfying the inequalities, Hn?1.5 kOe and 0.5 kOe?Hc?Hn?1.5 kOe.Type: GrantFiled: July 1, 2011Date of Patent: June 10, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Masatoshi Sakurai, Yousuke Isowaki, Soichi Oikawa
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Publication number: 20140139951Abstract: According to one embodiment, a perpendicular magnetic recording medium includes a nonmagnetic interlayer formed on a nonmagnetic substrate, an antiferromagnetic layer having a thickness of 2 to 30 nm, a first nonmagnetic underlayer having a thickness of 0.2 to 5 nm, a first bit patterned ferromagnetic layer, a first bit patterned nonmagnetic layer, and a second bit patterned ferromagnetic layer.Type: ApplicationFiled: January 24, 2014Publication date: May 22, 2014Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Tomoyuki Maeda, Yousuke Isowaki, Akira Watanabe, Akihiko Takeo
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Publication number: 20140049857Abstract: According to one embodiment, a magneto-resistance effect element includes: a first shield; a second shield; a first side shield layer; a second side shield layer; a stacked body; a first shield guide layer; and a second shield guide layer. The first shield guide layer includes a fifth magnetic layer provided between the first side shield layer and the stacked body. The second shield guide layer includes a sixth magnetic layer provided between the second side shield layer and the stacked body. A distance between the first side shield layer and the first shield guide layer is shorter than a distance between the stacked body and the first shield guide layer. A distance between the second side shield layer and the second shield guide layer is shorter than a distance between the stacked body and the second shield guide layer.Type: ApplicationFiled: July 11, 2013Publication date: February 20, 2014Inventors: Yousuke ISOWAKI, Hitoshi Iwasaki, Masayuki Takagishi
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Publication number: 20140043713Abstract: According to one embodiment, a magneto-resistance effect element includes a first shield, a second shield, a third shield, a first magnetic layer, a second magnetic layer, and an intermediate layer. The third shield is provided between the first shield and the second shield, and is in contact with the second shield. A length of the third shield along a first direction crossing a stacking direction from the first shield toward the second shield is shorter than a length along the first direction of the second shield. The first magnetic layer is provided between the first shield and the third shield. The second magnetic layer is provided between the first magnetic layer and the third shield, and is exchange-coupled to the third shield. The intermediate layer is provided between the first magnetic layer and the second magnetic layer.Type: ApplicationFiled: July 8, 2013Publication date: February 13, 2014Inventors: Yousuke ISOWAKI, Hitoshi IWASAKI, Masayuki TAKAGISHI
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Publication number: 20140042013Abstract: According to one embodiment, a magnetic recording medium includes a substrate, an auxiliary layer formed on the substrate, and at least one perpendicular magnetic recording layer formed on the auxiliary layer. The perpendicular magnetic recording layer includes a magnetic dot pattern. The perpendicular magnetic recording layer is made of an alloy material containing one element selected from iron and cobalt, and one element selected from platinum and palladium. This alloy material has the L10 structure, and is (001)-oriented. The auxiliary layer includes a dot-like first region covered with the magnetic dot pattern, and a second region not covered with the magnetic dot pattern. The first region is made of a (100)-oriented nickel oxide. The second region contains nickel used in the first region as a main component.Type: ApplicationFiled: October 16, 2013Publication date: February 13, 2014Applicant: Kabushiki Kaisha ToshibaInventors: Tomoyuki Maeda, Yousuke Isowaki, Akira Watanabe
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Patent number: 8634153Abstract: According to one embodiment, a magnetic recording medium includes a substrate, an auxiliary layer formed on the substrate, and at least one perpendicular magnetic recording layer formed on the auxiliary layer. The perpendicular magnetic recording layer includes a magnetic dot pattern. The perpendicular magnetic recording layer is made of an alloy material containing one element selected from iron and cobalt, and one element selected from platinum and palladium. This alloy material has the L10 structure, and is (001)-oriented. The auxiliary layer includes a dot-like first region covered with the magnetic dot pattern, and a second region not covered with the magnetic dot pattern. The first region is made of one metal selected from (100)-oriented nickel and (100)-oriented iron. The second region contains an oxide of the metal used in the first region.Type: GrantFiled: January 16, 2012Date of Patent: January 21, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Tomoyuki Maeda, Yousuke Isowaki, Akira Watanabe
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Publication number: 20130258523Abstract: A magnetic recording medium of an embodiment includes: a substrate; a nonmagnetic base layer disposed on the substrate; a perpendicular magnetic recording layer disposed on the nonmagnetic base layer, having a hard magnetic recording layer, a nonmagnetic intermediate layer, and a soft magnetic recording layer, and divided into mutually separated plural regions; and a protective layer disposed on the perpendicular magnetic recording layer. The hard magnetic recording layer has an easy magnetization axis directed to a stack direction of the hard magnetic recording layer. The nonmagnetic intermediate layer contains one of C, ZnO, a carbide of Si, Ti, Ta or W, and a nitride of Si, Ti, Ta or W.Type: ApplicationFiled: December 21, 2012Publication date: October 3, 2013Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Tomoyuki MAEDA, Hiroyuki HIEDA, Yousuke ISOWAKI, Takuya SHIMADA
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Patent number: 8333899Abstract: According to one embodiment, a method of manufacturing a magnetic recording medium includes forming on a magnetic recording layer a first hard mask, a second hard mask, a third hard mask and a resist, imprinting the resist with a stamper, removing a residue left in the recesses of the patterned resist, etching the third hard mask by use of the patterned resist as a mask, etching the second hard mask by use of the third hard mask as a mask, etching the first hard mask by use of the second hard mask as a mask, forming a pattern of the magnetic recording layer with ion beam irradiation, and removing the first hard mask by use of a remover liquid with higher reactivity to the metal material of the first hard mask than to a constituent element of the magnetic recording layer.Type: GrantFiled: January 14, 2011Date of Patent: December 18, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Masatoshi Sakurai, Kaori Kimura, Yousuke Isowaki, Akira Watanabe, Yoshiyuki Kamata
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Publication number: 20120275058Abstract: According to one embodiment, a magnetic recording medium includes a substrate, an auxiliary layer formed on the substrate, and at least one perpendicular magnetic recording layer formed on the auxiliary layer. The perpendicular magnetic recording layer includes a magnetic dot pattern. The perpendicular magnetic recording layer is made of an alloy material containing one element selected from iron and cobalt, and one element selected from platinum and palladium. This alloy material has the L10 structure, and is (001)-oriented. The auxiliary layer includes a dot-like first region covered with the magnetic dot pattern, and a second region not covered with the magnetic dot pattern. The first region is made of a (100)-oriented nickel oxide. The second region contains nickel used in the first region as a main component.Type: ApplicationFiled: January 16, 2012Publication date: November 1, 2012Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Tomoyuki Maeda, Yousuke Isowaki, Akira Watanabe
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Publication number: 20120276414Abstract: According to one embodiment, a perpendicular magnetic recording medium includes a nonmagnetic interlayer formed on a nonmagnetic substrate, an antiferromagnetic layer having a thickness of 2 to 30 nm, a first nonmagnetic underlayer having a thickness of 0.2 to 5 nm, a first bit patterned ferromagnetic layer, a first bit patterned nonmagnetic layer, and a second bit patterned ferromagnetic layer.Type: ApplicationFiled: January 13, 2012Publication date: November 1, 2012Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Tomoyuki MAEDA, Yousuke ISOWAKI, Akira WATANABE, Akihiko TAKEO
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Publication number: 20120275059Abstract: According to one embodiment, a magnetic recording medium includes a substrate, an auxiliary layer formed on the substrate, and at least one perpendicular magnetic recording layer formed on the auxiliary layer. The perpendicular magnetic recording layer includes a magnetic dot pattern. The perpendicular magnetic recording layer is made of an alloy material containing one element selected from iron and cobalt, and one element selected from platinum and palladium. This alloy material has the L10 structure, and is (001)-oriented. The auxiliary layer includes a dot-like first region covered with the magnetic dot pattern, and a second region not covered with the magnetic dot pattern. The first region is made of one metal selected from (100)-oriented nickel and (100)-oriented iron. The second region contains an oxide of the metal used in the first region.Type: ApplicationFiled: January 16, 2012Publication date: November 1, 2012Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Tomoyuki Maeda, Yousuke Isowaki, Akira Watanabe
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Patent number: 8298690Abstract: A magnetic recording medium includes a disk substrate, and recording cells arrayed on the disk substrate in a track direction, the recording cells includes a ferromagnetic pattern and a magnetic pattern formed on one of two sidewalls of the ferromagnetic pattern in the track direction and having a lower crystalline magnetic anisotropy constant Ku than that of the ferromagnetic pattern.Type: GrantFiled: November 20, 2008Date of Patent: October 30, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Hiroyuki Hieda, Kazuto Kashiwagi, Akira Kikitsu, Yousuke Isowaki, Yoshiyuki Kamata
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Patent number: 8206602Abstract: According to one embodiment, there is provided a method of manufacturing a magnetic recording medium, including forming a first hard mask including carbon as a main component, a second hard mask including a main component other than carbon and a resist on a magnetic recording layer, contacting a stamper to the resist to transfer patterns of protrusions and recesses to the resist, removing residues in the recesses of the patterned resist, etching the second hard mask, etching the first hard mask, patterning the magnetic recording layer, and removing the first hard mask, the method further including, between etching the first hard mask and removing the first hard mask, removing the second hard mask remaining on the protrusions of the first hard mask, and removing a contaminating layer on a surface of the first hard mask by a mixed gas of oxygen-based gas and a fluorine compound.Type: GrantFiled: July 16, 2010Date of Patent: June 26, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Kaori Kimura, Yousuke Isowaki, Yoshiyuki Kamata, Masatoshi Sakurai
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Publication number: 20120067843Abstract: A method of forming a fine pattern according to an embodiment includes: forming a hard mask on a substrate; forming a mask reinforcing member on the hard mask; forming a di-block copolymer layer on the mask reinforcing member, the di-block copolymer layer comprising a sea-island structure; forming a pattern comprising a concave-convex structure in the di-block copolymer layer, with island portions of the sea-island structure being convex portions; and transferring the pattern onto the hard mask by performing etching on the mask reinforcing member and the hard mask, with a mask being the pattern formed in the di-block copolymer layer. The mask reinforcing member is comprised of a material having an etching speed that is higher than an etching speed for the hard mask and is lower than an etching speed for sea portions of the sea-island structure of the di-block copolymer layer.Type: ApplicationFiled: March 16, 2011Publication date: March 22, 2012Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Akira Watanabe, Kaori Kimura, Yousuke Isowaki, Yoshiyuki Kamata, Naoko Kihara, Akira Kikitsu
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Publication number: 20120019960Abstract: According to one embodiment, a bit patterned medium includes a substrate, and a magnetic recording layer disposed above the substrate and including patterns of protrusions. Each of the protrusions contains a plurality of crystal grains. An average distance between the crystal grains is 0.5 to 3.0 nm in each of the protrusions. The protrusions include first protrusions each having a length of 1 ?m or more in a radial direction of the medium and second protrusions each having a length in the radial direction shorter than the length of the first protrusion in the radial direction. Each of the first protrusions has a nucleation field Hn for magnetization reversal and a coercive force Hc satisfying the inequalities, Hn?1.5 kOe and 0.5 kOe?Hc?Hn?1.5 kOe.Type: ApplicationFiled: July 1, 2011Publication date: January 26, 2012Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Masatoshi Sakurai, Yousuke Isowaki, Soichi Oikawa
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Patent number: 8057689Abstract: According to one embodiment, a method of manufacturing a magnetic recording medium includes forming a first hard mask, a second hard mask and a resist on a magnetic recording layer, imprinting a stamper to the resist to transfer patterns of protrusions and recesses to the resist, removing residues remaining in the recesses of the patterned resist by means of a first etching gas, etching the second hard mask by means of the first etching gas using the patterned resist as a mask to transfer the patterns to the second hard mask, etching the first hard mask by means of a second etching gas different from the first etching gas using the second hard mask as a mask to transfer the patterns to the first hard mask, and performing ion beam etching in order to deactivate the magnetic recording layer exposed in the recesses and to remove the second hard mask.Type: GrantFiled: February 12, 2010Date of Patent: November 15, 2011Assignee: Kabushiki Kaisha ToshibaInventors: Yousuke Isowaki, Kaori Kimura, Yoshiyuki Kamata, Masatoshi Sakurai
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Patent number: 8029682Abstract: According to one embodiment, a method of manufacturing a magnetic recording medium includes forming a first hard mask, a second hard mask and a resist on a magnetic recording layer, imprinting a stamper to the resist to transfer patterns of protrusions and recesses to the resist, removing residues remaining in the recesses of the patterned resist, etching the second hard mask by using the patterned resist as a mask to transfer the patterns of protrusions and recesses to the second hard mask, etching the first hard mask by using the second hard mask as a mask to transfer the patterns of protrusions and recesses to the first hard mask, subjecting the magnetic recording layer exposed in the recesses to modifying treatment to change an etching rate, and deactivating the magnetic recording layer exposed in the recesses.Type: GrantFiled: February 12, 2010Date of Patent: October 4, 2011Assignee: Kabushiki Kaisha ToshibaInventors: Yousuke Isowaki, Kaori Kimura, Yoshiyuki Kamata, Masatoshi Sakurai
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Publication number: 20110235212Abstract: According to one embodiment, a method of manufacturing a magnetic recording medium includes forming on a magnetic recording layer a first hard mask, a second hard mask, a third hard mask and a resist, imprinting the resist with a stamper, removing a residue left in the recesses of the patterned resist, etching the third hard mask by use of the patterned resist as a mask, etching the second hard mask by use of the third hard mask as a mask, etching the first hard mask by use of the second hard mask as a mask, forming a pattern of the magnetic recording layer with ion beam irradiation, and removing the first hard mask by use of a remover liquid with higher reactivity to the metal material of the first hard mask than to a constituent element of the magnetic recording layer.Type: ApplicationFiled: January 14, 2011Publication date: September 29, 2011Applicant: Kabushiki Kaisha ToshibaInventors: Masatoshi Sakurai, Kaori Kimura, Yousuke Isowaki, Akira Watanabe, Yoshiyuki Kamata