Patents by Inventor Risho Koh
Risho Koh 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: 10496782Abstract: According to an embodiment, element models include a first transistor model, a second transistor model, and a variable resistor model. The first transistor model simulates a characteristic of a selection gate transistor whose channel resistance is changed by a selection gate voltage applied to a selection gate. The second transistor model simulates a characteristic of a memory gate transistor whose channel resistance is changed by a memory gate voltage applied to a memory gate. The variable resistor model has a resistance value which is changed in accordance with the selection gate voltage and the memory gate voltage and which is set to correspond to a gap region formed in a lower part of an insulating film insulating between the selection gate and the memory gate. The variable resistor model is provided between the first transistor model and the second transistor model.Type: GrantFiled: December 5, 2017Date of Patent: December 3, 2019Assignee: RENESAS ELECTRONICS CORPORATIONInventors: Risho Koh, Mitsuru Miyamori, Katsumi Tsuneno
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Publication number: 20180181696Abstract: According to an embodiment, element models include a first transistor model, a second transistor model, and a variable resistor model. The first transistor model simulates a characteristic of a selection gate transistor whose channel resistance is changed by a selection gate voltage applied to a selection gate. The second transistor model simulates a characteristic of a memory gate transistor whose channel resistance is changed by a memory gate voltage applied to a memory gate. The variable resistor model has a resistance value which is changed in accordance with the selection gate voltage and the memory gate voltage and which is set to correspond to a gap region formed in a lower part of an insulating film insulating between the selection gate and the memory gate. The variable resistor model is provided between the first transistor model and the second transistor model.Type: ApplicationFiled: December 5, 2017Publication date: June 28, 2018Inventors: Risho Koh, Mitsuru Miyamori, Katsumi Tsuneno
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Patent number: 9558967Abstract: An improvement is achieved in the reliability of a semiconductor device by preventing a dielectric breakdown between two semiconductor chips facing each other. During the manufacturing of first and second semiconductor chips, the process of planarizing the upper surfaces of insulating films is performed. Then, the first and second semiconductor chips are stacked via an insulating sheet with the respective insulating films of the first and second semiconductor chips facing each other such that the respective coils of the first and second semiconductor chips are magnetically coupled to each other.Type: GrantFiled: October 30, 2015Date of Patent: January 31, 2017Assignee: Renesas Electronics CorporationInventors: Shinichi Uchida, Takafumi Kuramoto, Risho Koh
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Publication number: 20160197066Abstract: An improvement is achieved in the reliability of a semiconductor device by preventing a dielectric breakdown between two semiconductor chips facing each other. During the manufacturing of first and second semiconductor chips, the process of planarizing the upper surfaces of insulating films is performed. Then, the first and second semiconductor chips are stacked via an insulating sheet with the respective insulating films of the first and second semiconductor chips facing each other such that the respective coils of the first and second semiconductor chips are magnetically coupled to each other.Type: ApplicationFiled: October 30, 2015Publication date: July 7, 2016Inventors: Shinichi Uchida, Takafumi Kuramoto, Risho Koh
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Patent number: 8633726Abstract: A semiconductor device evaluation apparatus includes a current measurement portion that measures a current value at multiple times included in a period from the beginning of application of a voltage to a semiconductor device to a steady state of the current value flowing through the semiconductor device; a period division portion that divides the period into a first period and a second period later than the first period and finds a curve approximately representing a temporal change in a current value measured at time included in the second period so that a difference between a current value measured at the time included in the first period and a current value found by extrapolating the curve at the same time becomes greater than a specified threshold value; and a current estimation portion that estimates a current value flowing through the semiconductor device at the start time.Type: GrantFiled: January 17, 2012Date of Patent: January 21, 2014Assignee: Renesas Electronics CorporationInventors: Risho Koh, Takahiro Iizuka
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Publication number: 20120187975Abstract: A semiconductor device evaluation apparatus includes a current measurement portion that measures a current value at multiple times included in a period from the beginning of application of a voltage to a semiconductor device to a steady state of the current value flowing through the semiconductor device; a period division portion that divides the period into a first period and a second period later than the first period and finds a curve approximately representing a temporal change in a current value measured at time included in the second period so that a difference between a current value measured at the time included in the first period and a current value found by extrapolating the curve at the same time becomes greater than a specified threshold value; and a current estimation portion that estimates a current value flowing through the semiconductor device at the start time.Type: ApplicationFiled: January 17, 2012Publication date: July 26, 2012Inventors: Risho Koh, Takahiro Iizuka
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Patent number: 7830703Abstract: A semiconductor device having SRAM cell units each comprising a pair of a first driving transistor and a second driving transistor, a pair of a first load transistor and a second load transistor, and a pair of a first access transistor and a second access transistor, wherein each of the transistors comprises a semiconductor layer projecting upward from a substrate plane, a gate electrode extending on opposite sides of the semiconductor layer so as to stride over a top of the semiconductor layer, a gate insulating film interposed between the gate electrode and the semiconductor layer, and a pair of source/drain areas formed in the semiconductor layer; and the first and second driving transistors each have a channel width larger than that of at least either each of the load transistors or each of the access transistors.Type: GrantFiled: May 25, 2005Date of Patent: November 9, 2010Assignee: NEC CorporationInventors: Koichi Takeda, Masahiro Nomura, Kiyoshi Takeuchi, Hitoshi Wakabayashi, Shigeharu Yamagami, Risho Koh, Koichi Terashima, Katsuhiko Tanaka, Masayasu Tanaka
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Patent number: 7719043Abstract: The present invention relates to a semiconductor device including a Fin type field effect transistor (FET) having a protrusive semiconductor layer protruding from a substrate plane, a gate electrode formed so as to straddle the protrusive semiconductor layer, a gate insulating film between the gate electrode and the protrusive semiconductor layer, and source and drain regions provided in the protrusive semiconductor layer, wherein the semiconductor device has on a semiconductor substrate an element forming region having a Fin type FET, a trench provided on the semiconductor substrate for separating the element forming region from another element forming region, and an element isolation insulating film in the trench; the element forming region has a shallow substrate flat surface formed by digging to a depth shallower than the bottom surface of the trench and deeper than the upper surface of the semiconductor substrate, a semiconductor raised portion protruding from the substrate flat surface and formed of a pType: GrantFiled: July 4, 2005Date of Patent: May 18, 2010Assignee: NEC CorporationInventors: Shigeharu Yamagami, Hitoshi Wakabayashi, Risho Koh, Kiyoshi Takeuchi, Masahiro Nomura, Koichi Takeda, Koichi Terashima, Masayasu Tanaka, Katsuhiko Tanaka
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Patent number: 7611934Abstract: A semiconductor device includes (a) a semiconductor layer formed on an electrically insulating layer, (b) a gate insulating film formed on the semiconductor layer, (c) a gate electrode formed on the gate insulating film, and (d) a field insulating film formed on the semiconductor layer for defining a region in which a semiconductor device is to be fabricated. The semiconductor layer includes (a1) source and drain regions formed in the semiconductor layer around the gate electrode, the source and drain regions containing first electrically conductive type impurity, (a2) a body contact region formed in the semiconductor layer, the body contact region containing second electrically conductive type impurity, and (a3) a carrier path region formed in the semiconductor layer such that the carrier path region does not make contact with the source and drain regions, but makes contact with the body contact region, the carrier path region containing second electrically conductive type impurity.Type: GrantFiled: July 15, 2005Date of Patent: November 3, 2009Assignee: NEC CorporationInventors: Risho Koh, Yukishige Saito, Jong-Wook Lee, Hisashi Takemura
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Patent number: 7485923Abstract: A semiconductor device includes a first insulating layer, a semiconductor layer formed on the first insulating layer, a second insulating layer on a part of the semiconductor layer, and a gate electrode formed on the semiconductor layer through the second insulating layer. The semiconductor layer includes a low concentration region formed under the gate electrode through the second insulating layer, two high concentration regions which are formed in at least upper regions on outer sides of the low concentration region under the gate electrode through the second insulating layer, and have an impurity concentration higher than an impurity concentration of the low concentration region, respectively, and two source/drain regions which are formed in side portions of the high concentration regions to have low concentration region side end portions, respectively. A width of the high concentration region is equal to or less than 30 nm.Type: GrantFiled: October 2, 2002Date of Patent: February 3, 2009Assignee: NEC CorporationInventors: Hisashi Takemura, Risho Koh, Yukishige Saito, Jyonu Ri
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Publication number: 20090014795Abstract: A ? gate FinFET structure having reduced variations in off-current and parasitic capacitance and a method for production thereof are provided. The structure of an element is improved so that an off-current suppressing capability can be exhibited more strongly. A field effect transistor, wherein a first insulating film and a semiconductor region are provided so as to protrude upward with respect to the flat surface of a base, the field effect transistor has a gate electrode, a gate insulating film and a source/drain region, and a channel is formed at least on the side surface of the semiconductor region, wherein that the first insulating film is provided on an etch stopper layer composed of a material having an etching rate lower than at least the lowermost layer of the first insulating film for etching under a predetermined condition.Type: ApplicationFiled: July 14, 2005Publication date: January 15, 2009Inventors: Risho Koh, Katsuhiko Tanaka, Shigeharu Yamagami, Koichi Terashima, Hitoshi Wakabayashi, Kiyoshi Takeuchi, Masayasu Tanaka, Masahiro Nomura, Koichi Takeda
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Publication number: 20080079077Abstract: A semiconductor device having SRAM cell units each comprising a pair of a first driving transistor and a second driving transistor, a pair of a first load transistor and a second load transistor, and a pair of a first access transistor and a second access transistor, wherein each of the transistors comprises a semiconductor layer projecting upward from a substrate plane, a gate electrode extending on opposite sides of the semiconductor layer so as to stride over a top of the semiconductor layer, a gate insulating film interposed between the gate electrode and the semiconductor layer, and a pair of source/drain areas formed in the semiconductor layer; and the first and second driving transistors each have a channel width larger than that of at least either each of the load transistors or each of the access transistors.Type: ApplicationFiled: May 25, 2005Publication date: April 3, 2008Applicant: NEC CORPORATIONInventors: Koichi Takeda, Masahiro Nomura, Kiyoshi Takeuchi, Hitoshi Wakabayashi, Shigeharu Yamagami, Risho Koh, Koichi Terashima, Katsuhiko Tanaka, Masayasu Tanaka
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Publication number: 20080029821Abstract: The present invention relates to a semiconductor device including a Fin type field effect transistor (FET) having a protrusive semiconductor layer protruding from a substrate plane, a gate electrode formed so as to straddle the protrusive semiconductor layer, a gate insulating film between the gate electrode and the protrusive semiconductor layer, and source and drain regions provided in the protrusive semiconductor layer, wherein the semiconductor device has on a semiconductor substrate an element forming region having a Fin type FET, a trench provided on the semiconductor substrate for separating the element forming region from another element forming region, and an element isolation insulating film in the trench; the element forming region has a shallow substrate flat surface formed by digging to a depth shallower than the bottom surface of the trench and deeper than the upper surface of the semiconductor substrate, a semiconductor raised portion protruding from the substrate flat surface and formed of a pType: ApplicationFiled: July 4, 2005Publication date: February 7, 2008Applicant: NEC CORPORATIONInventors: Shigeharu Yamagami, Hitoshi Wakabayashi, Risho Koh, Kiyoshi Takeuchi, Masahiro Nomura, Koichi Takeda, Koichi Terashima, Masayasu Tanaka, Katsuhiko Tanaka
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Publication number: 20070257277Abstract: A semiconductor device having SRAM cell units each comprising a pair of driving transistors, a pair of load transistors and a pair of access transistors, in which each of the transistors has a semiconductor layer projecting upward from a substrate plane, a gate electrode extending on opposite sides of the semiconductor layer so as to stride over a top of the semiconductor layer, a gate insulting film interposed between the gate electrode and the semiconductor layer, and a pair of source/drain areas formed in the semiconductor layer; a longitudinal direction of each semiconductor layer extends along a first direction; and between the adjacent SRAM cell units in the first direction, the semiconductor layer in one of the corresponding transistors is located on a center line of the semiconductor layer in the other transistor which center line extends along the first direction.Type: ApplicationFiled: May 7, 2005Publication date: November 8, 2007Applicant: NEC CORPORATIONInventors: Koichi Takeda, Hitoshi Wakabayashi, Kiyoshi Takeuchi, Shigeharu Yamagami, Masahiro Nomura, Masayasu Tanaka, Koichi Terashima, Risho Koh, Katsuhiko Tanaka
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Publication number: 20070158700Abstract: A field effect transistor comprising: a semiconductor layer projecting from the plane of a base; a gate electrode provided on opposite side surfaces of the semiconductor layer; a gate insulating film interposed between the gate electrode and the side surface of the semiconductor layer; and source/drain regions where a first conductivity type impurity is introduced, wherein the semiconductor layer has a channel forming region in a portion sandwiched between the source/drain regions, and has in the upper part of the semiconductor layer in the channel forming region a channel impurity concentration adjusting region of which the concentration of a second conductivity type impurity is higher than that in the lower part of the semiconductor layer, and in the channel impurity concentration adjusting region, a channel is formed in a side surface portion facing the gate insulating film of the semiconductor layer in the channel impurity concentration adjusting region in a state of operation in which a signal voltage isType: ApplicationFiled: January 28, 2005Publication date: July 12, 2007Inventors: Risho Koh, Katsuhiko Tanaka, Kiyoshi Takeuchi
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Patent number: 7211517Abstract: A method of manufacturing a semiconductor device of the present invention includes (a) sequentially forming a gate insulating film 14, a first conductive layer 15 and a first insulating film 16 on a semiconductor layer 13 provided on an insulating film 12; (b) selectively removing the semiconductor layer, the gate insulating film, the first conductive layer and the first insulating film to form a device isolation trench; (c) forming a second insulating film 17 in the device isolation [element separation] trench, wherein a height of an upper surface of the second insulating film is substantially coincident with that of an upper surface of the first insulating film; (d) removing a part of the second insulating film and the first insulating film such that a height of an upper surface of the exposed first conductive layer is substantially coincident with that of the top surface of the second insulating film; and (e) patterning the first conductive layer to form a gate electrode.Type: GrantFiled: September 5, 2002Date of Patent: May 1, 2007Assignee: NEC CorporationInventors: Yukishige Saito, Risho Koh, Jyonu Ri, Hisashi Takemura
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Patent number: 6975001Abstract: A semiconductor device includes (a) a semiconductor layer formed on an electrically insulating layer, (b) a gate insulating film formed on the semiconductor layer, (c) a gate electrode formed on the gate insulating film, and (d) a field insulating film formed on the semiconductor layer for defining a region in which a semiconductor device is to be fabricated. The semiconductor layer includes (a1) source and drain regions formed in the semiconductor layer around the gate electrode, the source and drain regions containing first electrically conductive type impurity, (a2) a body contact region formed in the semiconductor layer, the body contact region containing second electrically conductive type impurity, and (a3) a carrier path region formed in the semiconductor layer such that the carrier path region does not make contact with the source and drain regions, but makes contact with the body contact region, the carrier path region containing second electrically conductive type impurity.Type: GrantFiled: June 6, 2002Date of Patent: December 13, 2005Assignee: NEC CorporationInventors: Risho Koh, Yukishige Saito, Jong-Wook Lee, Hisashi Takemura
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Publication number: 20050250317Abstract: A semiconductor device includes (a) a semiconductor layer formed on an electrically insulating layer, (b) a gate insulating film formed on the semiconductor layer, (c) a gate electrode formed on the gate insulating film, and (d) a field insulating film formed on the semiconductor layer for defining a region in which a semiconductor device is to be fabricated. The semiconductor layer includes (a1) source and drain regions formed in the semiconductor layer around the gate electrode, the source and drain regions containing first electrically conductive type impurity, (a2) a body contact region formed in the semiconductor layer, the body contact region containing second electrically conductive type impurity, and (a3) a carrier path region formed in the semiconductor layer such that the carrier path region does not make contact with the source and drain regions, but makes contact with the body contact region, the carrier path region containing second electrically conductive type impurity.Type: ApplicationFiled: July 15, 2005Publication date: November 10, 2005Inventors: Risho Koh, Yukishige Saito, Jong-Wook Lee, Hisashi Takemura
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Patent number: 6933569Abstract: A semiconductor device includes a semiconductor layer formed on an insulator, a gate insulating film formed on the semiconductor layer, a gate electrode formed on the gate insulating film and extending in a first direction, source/drain regions formed in the semiconductor layer on both sides of the gate electrode, a body contact region in the semiconductor layer, a partial isolating region in which a field insulating film thicker than the gate insulating film intervenes between the semiconductor layer and an extending portion of the gate electrode, and a full isolating region in which the semiconductor layer on the insulator is removed. The full isolating region is formed to be in contact with at least a part of a side parallel to the first direction of the source/drain regions.Type: GrantFiled: September 24, 2003Date of Patent: August 23, 2005Assignee: NEC CorporationInventors: Risho Koh, Shigeharu Yamagami, Jong-wook Lee, Hitoshi Wakabayashi, Yukishige Saito, Atsushi Ogura, Mitsuru Narihiro, Kohichi Arai, Hisashi Takemura, Tohru Mogami, Toyoji Yamamoto, Yukinori Ochiai
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Publication number: 20050151172Abstract: A semiconductor device includes a first insulating layer, a semiconductor layer formed on the first insulating layer, a second insulating layer on a part of the semiconductor layer, and a gate electrode formed on the semiconductor layer through the second insulating layer. The semiconductor layer includes a low concentration region formed under the gate electrode through the second insulating layer, two high concentration regions which are formed in at least upper regions on outer sides of the low concentration region under the gate electrode through the second insulating layer, and have an impurity concentration higher than an impurity concentration of the low concentration region, respectively, and two source/drain regions which are formed in side portions of the high concentration regions to have low concentration region side end portions, respectively. A width of the high concentration region is equal to or less than 30 nm.Type: ApplicationFiled: October 2, 2002Publication date: July 14, 2005Inventors: Hisashi Takemura, Risho Koh, Yukishige Saito, Jyonu Ri