Patents by Inventor Keiichi Murayama
Keiichi Murayama 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: 20240038758Abstract: A semiconductor device manufacturing method includes: forming a first groove having depth H in a semiconductor layer; filling the first groove with an oxide film and forming a surface oxide film having thickness a on an upper surface of the semiconductor layer to equalize the oxide film and the surface oxide film in height; forming a second groove having depth h greater than thickness a, from an uppermost surface of a third oxide film; forming gate trenches deeper than depth H, in the semiconductor layer; depositing polysilicon until at least the gate trenches and the second groove are filled with polysilicon; forming a peripheral element by injecting an impurity into polysilicon deposited in the second groove; and making a thickness of the peripheral element equal to depth h by concurrently removing polysilicon deposited in the gate trenches and polysilicon deposited in the second groove until they become equal in height.Type: ApplicationFiled: September 27, 2022Publication date: February 1, 2024Inventors: Kazumi TSUTSUMIDA, Katsuyoshi JOKYU, Keiichi MURAYAMA
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Publication number: 20110250726Abstract: Method for manufacturing a semiconductor device. A channel layer is formed by epitaxially growing a semiconductor layer, in which an ion species of a first conductivity is implanted on a semiconductor substrate. A source region, a drain region, and an emitter region which are of the first conductivity, are formed by activating, using annealing, a portion of the semiconductor substrate in which the ion species has been implanted. An emitter layer of the first conductivity, a base layer of a second conductivity having a band gap smaller than a band gap of the emitter layer, and a collector layer of the first conductivity or a non-doped collector layer are sequentially and epitaxially grown on the channel layer.Type: ApplicationFiled: June 22, 2011Publication date: October 13, 2011Applicant: PANASONIC CORPORATIONInventors: Keiichi MURAYAMA, Akiyoshi TAMURA, Kenichi MIYAJIMA
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Patent number: 8017975Abstract: A semiconductor device and manufacturing method satisfies both of the trade-off characteristic advantages of the HBT and the HFET. The semiconductor device is an HBT and HFET integrated circuit. The HBT includes a sub-collector layer, a GaAs collector layer, a GaAs base layer, and an InGaP emitter layer that are sequentially stacked. The sub-collector layer includes a GaAs external sub-collector region, and a GaAs internal sub-collector region disposed on the GaAs external sub-collector region. A mesa-shaped collector part and a collector electrode are separately formed on the GaAs external sub-collector region. The HFET includes a GaAs cap layer, a source electrode, and a drain electrode. The GaAs cap layer includes a portion of the GaAs external sub-collector region. The source electrode and the drain electrode are formed on the GaAs cap layer.Type: GrantFiled: March 9, 2009Date of Patent: September 13, 2011Assignee: Panasonic CorporationInventors: Keiichi Murayama, Akiyoshi Tamura, Hirotaka Miyamoto, Kenichi Miyajima
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Patent number: 7989845Abstract: The object of the present invention is to provide a semiconductor device and the manufacturing method thereof which are capable of preventing decrease in the collector breakdown voltage and reducing the collector resistance. The semiconductor device according to the present invention includes: a HBT formed on a first region of a semiconductor substrate; and an HFET formed on a second region of the semiconductor substrate, wherein the HBT includes: an emitter layer of a first conductivity; a base layer of a second conductivity that has a band gap smaller than that of the emitter layer; a collector layer of the first conductivity or a non-doped collector layer; and a sub-collector layer of the first conductivity which are formed sequentially on the first region, and the HFET includes an electron donor layer including a part of the emitter layer, and a channel layer formed under the electron donor layer.Type: GrantFiled: May 23, 2008Date of Patent: August 2, 2011Assignee: Panasonic CorporationInventors: Keiichi Murayama, Akiyoshi Tamura, Hirotaka Miyamoto, Kenichi Miyajima
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Publication number: 20100187571Abstract: An object of the present invention is to provide a semiconductor resistive element having excellent linearity. A semiconductor device according to the present invention includes a HBT which is formed on a GaAs substrate and includes a group III-V compound semiconductor, and a semiconductor resistive element made of at least one layer included in a semiconductor epitaxial layer included in the HBT, and the semiconductor resistive element includes helium impurities.Type: ApplicationFiled: January 20, 2010Publication date: July 29, 2010Applicant: PANASONIC CORPORATIONInventors: Kenichi MIYAJIMA, Akiyoshi TAMURA, Keiichi MURAYAMA
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Publication number: 20100171151Abstract: An HBT according to this invention includes: a sub-collector layer; a collector layer formed on the sub-collector layer and the base layer including a first collector layer, a second collector layer, a third collector layer, and a fourth collector layer. The first collector layer is formed on the sub-collector layer, and is made of semiconductor different from semiconductor of which the second to the fourth collector layers are made. The fourth collector layer is formed on the first collector layer, and has an impurity concentration lower than an impurity concentration of the second collector layer. The second collector layer is formed on the fourth collector layer, and has an impurity concentration lower than an impurity concentration of the sub-collector layer and higher than an impurity concentration of the third collector layer. The third collector layer is formed between the second collector layer and the base layer.Type: ApplicationFiled: December 29, 2009Publication date: July 8, 2010Applicant: PANASONIC CORPORATIONInventors: Kenichi MIYAJIMA, Akiyoshi TAMURA, Keiichi MURAYAMA, Hirotaka MIYAMOTO
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Patent number: 7728357Abstract: The object of the present invention is to provide a heterojunction bipolar transistor with high breakdown tolerance which can be manufactured at a high reproducibility and a high yield, the heterojunction bipolar transistor includes: a sub-collector layer; a collector layer formed on the sub-collector layer; a base layer formed on the collector layer; and an emitter layer, which is formed on the base layer and is made of a semiconductor that has a larger bandgap than a semiconductor of the base layer, in which the collector layer includes: a first collector layer formed on the sub-collector layer; a second collector layer formed on the first collector layer; and a third collector layer formed between the second collector layer and the base layer, a semiconductor of the first collector layer differs from semiconductors of the third collector layer and the second collector layer, and an impurity concentration of the second collector layer is lower than an impurity concentration of the sub-collector layer and hiType: GrantFiled: December 21, 2006Date of Patent: June 1, 2010Assignee: Panasonic CorporationInventors: Keiichi Murayama, Akiyoshi Tamura, Hirotaka Miyamoto, Kenichi Miyajima
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Publication number: 20090230431Abstract: The present invention has as an objective to provide: a semiconductor device to satisfy both of the trade-off characteristic advantages of the HBT; and the HFET and a manufacturing method thereof. The semiconductor device in the present invention is an HBT and HFET integrated circuit. The HBT includes a sub-collector layer, a GaAs collector layer, a GaAs base layer, and an InGaP emitter layer which are sequentially stacked. The sub-collector layer includes a GaAs external sub-collector region, and a GaAs internal sub-collector region disposed on the GaAs external sub-collector region. A mesa-shaped collector part and a collector electrode are separately formed on the GaAs external sub-collector region. The HFET includes a GaAs cap layer, a source electrode, and a drain electrode, the GaAs cap layer including portion of the GaAs external sub-collector region, and the source electrode and the drain electrode being formed on the GaAs cap layer.Type: ApplicationFiled: March 9, 2009Publication date: September 17, 2009Applicant: PANASONIC CORPORATIONInventors: Keiichi MURAYAMA, Akiyoshi TAMURA, Hirotaka MIYAMOTO, Kenichi MIYAJIMA
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Patent number: 7566920Abstract: A base mesa finger (an emitter ledge layer 15, a base layer 16, and a collector layer 17) is interposed between two collector fingers (collector electrodes 13), and on the base mesa finger, a base finger (a base electrode 12) and two emitter fingers (an emitter layer 14 and an emitter electrode 11) on both sides of the base finger, are formed. The two emitter fingers are formed symmetric with respect to the base finger as a reference.Type: GrantFiled: July 12, 2006Date of Patent: July 28, 2009Assignee: Panasonic CorporationInventors: Katsuhiko Kawashima, Masahiro Maeda, Keiichi Murayama, Hirotaka Miyamoto
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Publication number: 20080296624Abstract: The object of the present invention is to provide a semiconductor device and the manufacturing method thereof which are capable of preventing decrease in the collector breakdown voltage and reducing the collector resistance. The semiconductor device according to the present invention includes: a HBT formed on a first region of a semiconductor substrate; and an HFET formed on a second region of the semiconductor substrate, wherein the HBT includes: an emitter layer of a first conductivity; a base layer of a second conductivity that has a band gap smaller than that of the emitter layer; a collector layer of the first conductivity or a non-doped collector layer; and a sub-collector layer of the first conductivity which are formed sequentially on the first region, and the HFET includes an electron donor layer including a part of the emitter layer, and a channel layer formed under the electron donor layer.Type: ApplicationFiled: May 23, 2008Publication date: December 4, 2008Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.Inventors: Keiichi MURAYAMA, Akiyoshi TAMURA, Hirotaka MIYAMOTO, Kenichi MIYAJIMA
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Patent number: 7449729Abstract: On a high-concentration n-type first sub-collector layer, a high-concentration n-type second sub-collector layer made of a material having a small bandgap, an i-type or low-concentration n-type collector layer, a high-concentration p-type base layer, an n-type emitter layer made of a material having a large bandgap, a high-concentration n-type emitter cap layer, a high-concentration n-type emitter contact layer made of a material having a small bandgap are sequentially stacked. From the emitter contact layer, an interconnection also serving as an emitter electrode is extended. From the emitter layer or the base layer, an interconnection also serving as a base electrode is extended. From the second sub-collector layer, an interconnection also serving as a collector electrode is extended.Type: GrantFiled: April 6, 2006Date of Patent: November 11, 2008Assignee: Panasonic CorporationInventors: Kenichi Miyajima, Keiichi Murayama, Hirotaka Miyamoto
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Publication number: 20080176391Abstract: The present invention has an object of providing a method for manufacturing a semiconductor device which can prevent occurrence of pattern abnormality of an electrode and deterioration of an electronic property. The method for manufacturing the semiconductor device including a GaAs substrate with a portion made of GaAs includes: forming a Ti/Pt/Au/Ti electrode on the GaAs substrate, the electrode including Pt and having a layered structure in which a top layer made of Ti; forming a collector electrode including AuGe on a portion made of GaAs; and performing heat treatment on the collector electrode in a state where both of the Ti/Pt/Au/Ti electrode and the collector electrode are exposed to a surface.Type: ApplicationFiled: January 23, 2008Publication date: July 24, 2008Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.Inventors: Hirotaka MIYAMOTO, Akiyoshi TAMURA, Keiichi MURAYAMA, Kenichi MIYAJIMA
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Publication number: 20080088020Abstract: Provided is a semiconductor device and a manufacturing method of the same which improve adhesion of a semiconductor substrate to a metal wire, the semiconductor substrate having a via hole formed from a bottom surface of the semiconductor substrate up to the metal wire on a top surface of the semiconductor substrate, and the metal wire being positioned on the top surface of the semiconductor substrate where there is an opening formed since the via hole is formed. The semiconductor device includes: a metal layer formed on a semiconductor substrate; an alloy reaction layer formed below the metal layer as a result of an alloy reaction between the semiconductor substrate and the metal layer; and a via hole formed from a bottom surface side of the semiconductor substrate up to the metal layer or up to the alloy reaction layer.Type: ApplicationFiled: July 9, 2007Publication date: April 17, 2008Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.Inventors: Kenichi MIYAJIMA, Keiichi MURAYAMA, Hirotaka MIYAMOTO, Akiyoshi TAMURA
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Patent number: 7301181Abstract: The present invention aims at providing a heterojunction bipolar transistor having improved breakdown voltage on operation for high power output, and includes: a GaAs semiconductor substrate 100; an n+-type GaAs sub-collector layer 110; an n-type GaAs collector layer 120; a p-type GaAs base layer 130; an emitter layer 140; an n-type GaAs emitter cap layer 150; and an n-type InGaAs emitter contact layer 160. The emitter layer 140 has a multilayer structure including an n-type or non-doped first emitter layer 141 and an n-type second emitter layer 142 which are laminated in sequence. The first emitter layer 141 is made of a semiconductor material including Al, while the second emitter layer 142 is made of InxGa1-xP (0<x<1).Type: GrantFiled: November 4, 2004Date of Patent: November 27, 2007Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Keiichi Murayama, Yorito Ota, Akiyoshi Tamura
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Publication number: 20070145412Abstract: The object of the present invention is to provide a heterojunction bipolar transistor with high breakdown tolerance which can be manufactured at a high reproducibility and a high yield, the heterojunction bipolar transistor includes: a sub-collector layer; a collector layer formed on the sub-collector layer; a base layer formed on the collector layer; and an emitter layer, which is formed on the base layer and is made of a semiconductor that has a larger bandgap than a semiconductor of the base layer, in which the collector layer includes: a first collector layer formed on the sub-collector layer; a second collector layer formed on the first collector layer; and a third collector layer formed between the second collector layer and the base layer, a semiconductor of the first collector layer differs from semiconductors of the third collector layer and the second collector layer, and an impurity concentration of the second collector layer is lower than an impurity concentration of the sub-collector layer and hiType: ApplicationFiled: December 21, 2006Publication date: June 28, 2007Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.Inventors: Keiichi MURAYAMA, Akiyoshi TAMURA, Hirotaka MIYAMOTO, Kenichi MIYAJIMA
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Patent number: 7176099Abstract: A hetero-junction bipolar transistor that satisfies high resistance required to avoid a potential breakdown includes: an n-type sub-collector layer 110 that is made of GaAs; an n-type first collector 121 that is made of a semiconductor material with a smaller avalanche coefficient than that of the sub-collector 110 and is formed on the sub-collector layer 110; a second collector layer 132 that is made of n-type or i-type GaAs with lower dopant concentration than that of the sub-collector layer 110 and is formed on the first collector layer 121; a p-type base layer 133 that is made of GaAs and is formed on the second collector layer 132; and emitter layer 134 that is made of a semiconductor material with a larger band gap than that of the base layer 133 and is formed on the base layer 133.Type: GrantFiled: April 7, 2005Date of Patent: February 13, 2007Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Keiichi Murayama, Akiyoshi Tamura, Masanobu Nogome
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Patent number: 7176098Abstract: A heterojunction bipolar transistor comprises a collector layer, a base layer formed on the collector layer and an emitter layer formed on the base layer. The emitter layer includes a first semiconductor layer covering the entire top surface of the base layer and a second semiconductor layer formed on a predetermined part of the first semiconductor layer. An inactivated region is formed, by ion implantation, in a region of the collector layer located below the base layer except for a part thereof corresponding to the second semiconductor layer. The edge of the inactivated region is located away from the edge of the second semiconductor layer, and a region of the first semiconductor layer between the edge of the inactivated region and the edge of the second semiconductor layer is depleted.Type: GrantFiled: February 23, 2005Date of Patent: February 13, 2007Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Keisuke Kojima, Toshiharu Tanbo, Keiichi Murayama
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Publication number: 20070012949Abstract: A base mesa finger (an emitter ledge layer 15, a base layer 16, and a collector layer 17) is interposed between two collector fingers (collector electrodes 13), and on the base mesa finger, a base finger (a base electrode 12) and two emitter fingers (an emitter layer 14 and an emitter electrode 11) on both sides of the base finger, are formed. The two emitter fingers are formed symmetric with respect to the base finger as a reference.Type: ApplicationFiled: July 12, 2006Publication date: January 18, 2007Inventors: Katsuhiko Kawashima, Masahiro Maeda, Keiichi Murayama, Hirotaka Miyamoto
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Publication number: 20060289896Abstract: A semiconductor device has an interconnect layer for providing an electric connection between a base electrode and a base terminal provided on the region of a semi-insulating substrate on which a transistor is not formed. A resistor layer composed of a material different from respective materials composing the base electrode and the interconnect layer is formed on the base electrode and the base electrode and the interconnect layer are connected to each other via the resistor layer.Type: ApplicationFiled: February 7, 2006Publication date: December 28, 2006Inventors: Hirotaka Miyamoto, Keiichi Murayama, Kenichi Miyajima
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Publication number: 20060284212Abstract: A high-performance hetero-junction bipolar transistor with good processibility and which does not increase ON resistance (Ron), and a manufacturing method thereof are provided. The hetero-junction bipolar transistor includes a sub-collector layer made of n-type GaAs, a second collector layer made of n-type GaAs having a lower impurity concentration than the impurity the sub-collector layer, and a first collector layer that is formed between the sub-collector layer and the second collector layer, and that has a resistance to an etchant used for etching the second collector layer and that allows conduction of electrons at a junction with the second collector layer.Type: ApplicationFiled: March 17, 2006Publication date: December 21, 2006Applicant: Matsushita Electric Industrial Co., LtdInventors: Keiichi Murayama, Akiyoshi Tamura