Patents by Inventor Hiroyuki Takazawa
Hiroyuki Takazawa 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: 8537505Abstract: According to one embodiment, a magnetoresistive effect head includes a lower magnetic shield provided on a substrate, a magnetoresistive effect film laminated from a pinned layer with a pinned direction of magnetization, an intermediate layer, a free layer having a varying direction of magnetization controlled by an applied external magnetic field, a magnetic domain control layer formed with an intervening insulation layer on both sides in a track width direction of the magnetoresistive effect film, an upper magnetic shield, and electrodes for directing sense current flow in a direction perpendicular to a film surface of the magnetoresistive effect film, wherein a magnetic field applied by the magnetic domain control layer to a region away from an ABS of the free layer is at least 1.4 times larger than a magnetic field applied by the magnetic domain control layer to a region near the ABS of the free layer.Type: GrantFiled: May 20, 2010Date of Patent: September 17, 2013Assignee: HGST Netherlands B.V.Inventors: Masato Shiimoto, Kan Yasui, Nobuo Yoshida, Hiroyuki Takazawa
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Patent number: 8385847Abstract: A switching element is provided that realizes an stabilize a potential between the gates of the multi-gates without an increase in the insertion loss, and an antenna switch circuit and a radio frequency module each using the switch element. The switching element includes two ohmic electrodes 39, 40 formed on a semiconductor substrate, at least two gate electrodes 41, 42 disposed between the two ohmic electrodes, and a conductive region 45 disposed between the adjacent gate electrodes among the at least two gate electrodes, a field effective transistor being structured by the two ohmic electrodes, the at least two gate electrodes, and the conductive region. The conductive region has a wider portion that is wider in width than the conductive region interposed between the adjacent gate electrodes on one end thereof. The distance between the adjacent gate electrodes is narrower than the width of the wider portion. Resistors 44, 46 are connected in series between the two ohmic electrodes through the wider portion.Type: GrantFiled: February 25, 2011Date of Patent: February 26, 2013Assignee: Renesas Electronics CorporationInventors: Takashi Ogawa, Shinichiro Takatani, Shigeki Koya, Hiroyuki Takazawa, Shinya Osakabe, Akishige Nakajima, Yasushi Shigeno
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Patent number: 8169008Abstract: The present invention miniaturizes a HEMT element used as a switching element in a radio frequency module. A single gate electrode 17 is formed in an active region defined by an element separation portion 9 on a main surface of a substrate 1 comprising GaAs. The gate electrode 17 is patterned so as to extend in the vertical direction of the page surface between source electrodes 13 and drain electrodes 14, and to extend in left and right directions at other portions. Thus, the ratio of the gate electrode 17 disposed outside the active region is reduced, and the area of a gate pad 17A is reduced.Type: GrantFiled: October 21, 2010Date of Patent: May 1, 2012Assignee: Murata Manufacturing Co., Ltd.Inventors: Masao Yamane, Atsushi Kurokawa, Shinya Osakabe, Eigo Tange, Yasushi Shigeno, Hiroyuki Takazawa
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Publication number: 20110156983Abstract: A switching element is provided that realizes an stabilize a potential between the gates of the multi-gates without an increase in the insertion loss, and an antenna switch circuit and a radio frequency module each using the switch element. The switching element includes two ohmic electrodes 39, 40 formed on a semiconductor substrate, at least two gate electrodes 41, 42 disposed between the two ohmic electrodes, and a conductive region 45 disposed between the adjacent gate electrodes among the at least two gate electrodes, a field effective transistor being structured by the two ohmic electrodes, the at least two gate electrodes, and the conductive region. The conductive region has a wider portion that is wider in width than the conductive region interposed between the adjacent gate electrodes on one end thereof. The distance between the adjacent gate electrodes is narrower than the width of the wider portion. Resistors 44, 46 are connected in series between the two ohmic electrodes through the wider portion.Type: ApplicationFiled: February 25, 2011Publication date: June 30, 2011Inventors: Takashi Ogawa, Shinichiro Takatani, Shigeki Koya, Hiroyuki Takazawa, Shinya Osakabe, Akishige Nakajima, Yasushi Shigeno
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Patent number: 7899412Abstract: A switching element is provided that realizes an stabilize a potential between the gates of the multi-gates without an increase in the insertion loss, and an antenna switch circuit and a radio frequency module each using the switch element. The switching element includes two ohmic electrodes 39, 40 formed on a semiconductor substrate, at least two gate electrodes 41, 42 disposed between the two ohmic electrodes, and a conductive region 45 disposed between the adjacent gate electrodes among the at least two gate electrodes, a field effective transistor being structured by the two ohmic electrodes, the at least two gate electrodes, and the conductive region. The conductive region has a wider portion that is wider in width than the conductive region interposed between the adjacent gate electrodes on one end thereof. The distance between the adjacent gate electrodes is narrower than the width of the wider portion. Resistors 44, 46 are connected in series between the two ohmic electrodes through the wider portion.Type: GrantFiled: July 29, 2010Date of Patent: March 1, 2011Assignee: Renesas Electronics CorporationInventors: Takashi Ogawa, Shinichiro Takatani, Shigeki Koya, Hiroyuki Takazawa, Shinya Osakabe, Akishige Nakajima, Yasushi Shigeno
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Publication number: 20110031533Abstract: The present invention miniaturizes a HEMT element used as a switching element in a radio frequency module. A single gate electrode 17 is formed in an active region defined by an element separation portion 9 on a main surface of a substrate 1 comprising GaAs. The gate electrode 17 is patterned so as to extend in the vertical direction of the page surface between source electrodes 13 and drain electrodes 14, and to extend in left and right directions at other portions. Thus, the ratio of the gate electrode 17 disposed outside the active region is reduced, and the area of a gate pad 17A is reduced.Type: ApplicationFiled: October 21, 2010Publication date: February 10, 2011Applicant: RENESAS ELECTRONICS CORPORATIONInventors: Masao Yamane, Atsushi Kurokawa, Shinya Osakabe, Eigo Tange, Yasushi Shigeno, Hiroyuki Takazawa
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Publication number: 20100302688Abstract: According to one embodiment, a magnetoresistive effect head includes a lower magnetic shield provided on a substrate, a magnetoresistive effect film laminated from a pinned layer with a pinned direction of magnetization, an intermediate layer, a free layer having a varying direction of magnetization controlled by an applied external magnetic field, a magnetic domain control layer formed with an intervening insulation layer on both sides in a track width direction of the magnetoresistive effect film, an upper magnetic shield, and electrodes for directing sense current flow in a direction perpendicular to a film surface of the magnetoresistive effect film, wherein a magnetic field applied by the magnetic domain control layer to a region away from an ABS of the free layer is at least 1.4 times larger than a magnetic field applied by the magnetic domain control layer to a region near the ABS of the free layer.Type: ApplicationFiled: May 20, 2010Publication date: December 2, 2010Inventors: Masato Shiimoto, Kan Yasui, Nobuo Yoshida, Hiroyuki Takazawa
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Publication number: 20100297960Abstract: A switching element is provided that realizes an stabilize a potential between the gates of the multi-gates without an increase in the insertion loss, and an antenna switch circuit and a radio frequency module each using the switch element. The switching element includes two ohmic electrodes 39, 40 formed on a semiconductor substrate, at least two gate electrodes 41, 42 disposed between the two ohmic electrodes, and a conductive region 45 disposed between the adjacent gate electrodes among the at least two gate electrodes, a field effective transistor being structured by the two ohmic electrodes, the at least two gate electrodes, and the conductive region. The conductive region has a wider portion that is wider in width than the conductive region interposed between the adjacent gate electrodes on one end thereof. The distance between the adjacent gate electrodes is narrower than the width of the wider portion. Resistors 44, 46 are connected in series between the two ohmic electrodes through the wider portion.Type: ApplicationFiled: July 29, 2010Publication date: November 25, 2010Inventors: Takashi Ogawa, Shinichiro Takatani, Shigeki Koya, Hiroyuki Takazawa, Shinya Osakabe, Akishige Nakajima, Yasushi Shigeno
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Patent number: 7838914Abstract: The present invention miniaturizes a HEMT element used as a switching element in a radio frequency module. A single gate electrode 17 is formed in an active region defined by an element separation portion 9 on a main surface of a substrate 1 comprising GaAs. The gate electrode 17 is patterned so as to extend in the vertical direction of the page surface between source electrodes 13 and drain electrodes 14, and to extend in left and right directions at other portions. Thus, the ratio of the gate electrode 17 disposed outside the active region is reduced, and the area of a gate pad 17A is reduced.Type: GrantFiled: November 6, 2007Date of Patent: November 23, 2010Assignee: Renesas Electronics CorporationInventors: Masao Yamane, Atsushi Kurokawa, Shinya Osakabe, Eigo Tange, Yasushi Shigeno, Hiroyuki Takazawa
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Patent number: 7783265Abstract: A switching element is provided that realizes an stabilize a potential between the gates of the multi-gates without an increase in the insertion loss, and an antenna switch circuit and a radio frequency module each using the switch element. The switching element includes two ohmic electrodes 39, 40 formed on a semiconductor substrate, at least two gate electrodes 41, 42 disposed between the two ohmic electrodes, and a conductive region 45 disposed between the adjacent gate electrodes among the at least two gate electrodes, a field effective transistor being structured by the two ohmic electrodes, the at least two gate electrodes, and the conductive region. The conductive region has a wider portion that is wider in width than the conductive region interposed between the adjacent gate electrodes on one end thereof. The distance between the adjacent gate electrodes is narrower than the width of the wider portion. Resistors 44, 46 are connected in series between the two ohmic electrodes through the wider portion.Type: GrantFiled: December 15, 2008Date of Patent: August 24, 2010Assignee: Renesas Technology Corp.Inventors: Takashi Ogawa, Shinichiro Takatani, Shigeki Koya, Hiroyuki Takazawa, Shinya Osakabe, Akishige Nakajima, Yasushi Shigeno
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Patent number: 7768066Abstract: A UMOSFET is capable of reducing a threshold voltage and producing a large saturation current. A typical UMOSFET according to the present invention includes: an N+ type SiC substrate constituting a drain layer; an N? type SiC layer that is in contact with the drain layer and constitutes a drift layer; a P type body layer formed on the drift layer and being a semiconductor layer; an N+ type SiC layer constituting a source layer; a trench extending from the source layer to a predetermined location placed in the drift layer; a P type electric field relaxation region provided around and outside a bottom portion of the trench; and a channel region extending from the N+ type source layer to the P type electric field relaxation region and having an impurity concentration higher than that of the N? type drift layer and lower than that of the P type body layer.Type: GrantFiled: July 24, 2008Date of Patent: August 3, 2010Assignee: Hitachi, Ltd.Inventors: Hidekatsu Onose, Hiroyuki Takazawa
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Publication number: 20090104881Abstract: A switching element is provided that realizes an stabilize a potential between the gates of the multi-gates without an increase in the insertion loss, and an antenna switch circuit and a radio frequency module each using the switch element. The switching element includes two ohmic electrodes 39, 40 formed on a semiconductor substrate, at least two gate electrodes 41, 42 disposed between the two ohmic electrodes, and a conductive region 45 disposed between the adjacent gate electrodes among the at least two gate electrodes, a field effective transistor being structured by the two ohmic electrodes, the at least two gate electrodes, and the conductive region. The conductive region has a wider portion that is wider in width than the conductive region interposed between the adjacent gate electrodes on one end thereof. The distance between the adjacent gate electrodes is narrower than the width of the wider portion. Resistors 44, 46 are connected in series between the two ohmic electrodes through the wider portion.Type: ApplicationFiled: December 15, 2008Publication date: April 23, 2009Inventors: Takashi Ogawa, Shinichiro Takatani, Shigeki Koya, Hiroyuki Takazawa, Shinya Osakabe, Akishige Nakajima, Yasushi Shigeno
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Publication number: 20090032821Abstract: A UMOSFET is capable of reducing a threshold voltage and producing a large saturation current. A typical UMOSFET according to the present invention includes: an N+ type SiC substrate constituting a drain layer; an N? type SiC layer that is in contact with the drain layer and constitutes a drift layer; a P type body layer formed on the drift layer and being a semiconductor layer; an N+ type SiC layer constituting a source layer; a trench extending from the source layer to a predetermined location placed in the drift layer; a P type electric field relaxation region provided around and outside a bottom portion of the trench; and a channel region extending from the N+ type source layer to the P type electric field relaxation region and having an impurity concentration higher than that of the N? type drift layer and lower than that of the P type body layer.Type: ApplicationFiled: July 24, 2008Publication date: February 5, 2009Inventors: Hidekatsu Onose, Hiroyuki Takazawa
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Publication number: 20080073671Abstract: The present invention miniaturizes a HEMT element used as a switching element in a radio frequency module. A single gate electrode 17 is formed in an active region defined by an element separation portion 9 on a main surface of a substrate 1 comprising GaAs. The gate electrode 17 is patterned so as to extend in the vertical direction of the page surface between source electrodes 13 and drain electrodes 14, and to extend in left and right directions at other portions. Thus, the ratio of the gate electrode 17 disposed outside the active region is reduced, and the area of a gate pad 17A is reduced.Type: ApplicationFiled: November 6, 2007Publication date: March 27, 2008Inventors: Masao Yamane, Atsushi Kurokawa, Shinya Osakabe, Eigo Tange, Yasushi Shigeno, Hiroyuki Takazawa
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Patent number: 7307298Abstract: The present invention miniaturizes a HEMT element used as a switching element in a radio frequency module. A single gate electrode 17 is formed in an active region defined by an element separation portion 9 on a main surface of a substrate 1 comprising GaAs. The gate electrode 17 is patterned so as to extend in the vertical direction of the page surface between source electrodes 13 and drain electrodes 14, and to extend in left and right directions at other portions. Thus, the ratio of the gate electrode 17 disposed outside the active region is reduced, and the area of a gate pad 17A is reduced.Type: GrantFiled: November 17, 2004Date of Patent: December 11, 2007Assignee: Renesas Technology Corp.Inventors: Masao Yamane, Atsushi Kurokawa, Shinya Osakabe, Eigo Tange, Yasushi Shigeno, Hiroyuki Takazawa
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Publication number: 20060118951Abstract: A switching element is provided that realizes an stabilize a potential between the gates of the multi-gates without an increase in the insertion loss, and an antenna switch circuit and a radio frequency module each using the switch element. The switching element includes two ohmic electrodes 39, 40 formed on a semiconductor substrate, at least two gate electrodes 41, 42 disposed between the two ohmic electrodes, and a conductive region 45 disposed between the adjacent gate electrodes among the at least two gate electrodes, a field effective transistor being structured by the two ohmic electrodes, the at least two gate electrodes, and the conductive region. The conductive region has a wider portion that is wider in width than the conductive region interposed between the adjacent gate electrodes on one end thereof. The distance between the adjacent gate electrodes is narrower than the width of the wider portion. Resistors 44, 46 are connected in series between the two ohmic electrodes through the wider portion.Type: ApplicationFiled: December 2, 2005Publication date: June 8, 2006Inventors: Takashi Ogawa, Shinichiro Takatani, Shigeki Koya, Hiroyuki Takazawa, Shinya Osakabe, Akishige Nakajima, Yasushi Shigeno
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Publication number: 20050116253Abstract: The present invention miniaturizes a HEMT element used as a switching element in a radio frequency module. A single gate electrode 17 is formed in an active region defined by an element separation portion 9 on a main surface of a substrate 1 comprising GaAs. The gate electrode 17 is patterned so as to extend in the vertical direction of the page surface between source electrodes 13 and drain electrodes 14, and to extend in left and right directions at other portions. Thus, the ratio of the gate electrode 17 disposed outside the active region is reduced, and the area of a gate pad 17A is reduced.Type: ApplicationFiled: November 17, 2004Publication date: June 2, 2005Inventors: Masao Yamane, Atsushi Kurokawa, Shinya Osakabe, Eigo Tange, Yasushi Shigeno, Hiroyuki Takazawa
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Patent number: 6787817Abstract: The present invention provides a semiconductor device for high frequency application having a high breakdown voltage and the method of manufacturing thereof. A region including a first conductivity type high impurity concentration semiconductor and a region including a first conductivity type low impurity concentration semiconductor are provided from an ohmic layer side at the side far from a semiconductor substrate of the end surface of a barrier layer opposite the semiconductor substrate and between the ohmic layer and a gate electrode. The sheet impurity concentration of the region including a first conductivity type low impurity concentration semiconductor is set to be lower than that between the bottom surface of the gate electrode at the side of the semiconductor substrate and the end surface of the channel layer opposite the semiconductor substrate.Type: GrantFiled: December 13, 2002Date of Patent: September 7, 2004Assignee: Renesas Technology CorporationInventors: Hiroyuki Takazawa, Shinichiro Takatani, Masao Yamane, Masayoshi Kobayashi
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Patent number: 6724020Abstract: A semiconductor device comprising a bipolar transistor having an emitter layer consisting of a semiconductor containing indium, and a protective insulating film containing silicon and oxygen which is formed on the surface of the guard ring of the emitter layer, wherein the protective insulating film has a density of oxygen of less than 7×1022 cm−3. This semiconductor device prevents performance deterioration and ensures high performance in a power amplifier.Type: GrantFiled: April 23, 2003Date of Patent: April 20, 2004Assignee: Renesas Technology CorporationInventors: Hiroyuki Takazawa, Tohru Oka, Isao Ohbu, Yoshinori Imamura
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Publication number: 20030205719Abstract: A semiconductor device comprising a bipolar transistor having an emitter layer consisting of a semiconductor containing indium, and a protective insulating film containing silicon and oxygen which is formed on the surface of the guard ring of the emitter layer, wherein the protective insulating film has a density of oxygen of less than 7×1022 cm−3. This semiconductor device prevents performance deterioration and ensures high performance in a power amplifier.Type: ApplicationFiled: April 23, 2003Publication date: November 6, 2003Applicant: Hitachi, Ltd.Inventors: Hiroyuki Takazawa, Tohru Oka, Isao Ohbu, Yoshinori Imamura