Patents by Inventor Atsushi Yagishita
Atsushi Yagishita 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: 6794720Abstract: In a semiconductor device in which the gate electrode of a MISFET formed on a semiconductor substrate is electrically connected to a well region under the channel of the MISFET, the MISFET is formed in an island-shaped element region formed on the semiconductor substrate, and electrical connection between the gate electrode of the MISFET and the well region in the semiconductor substrate is done on the side surface of the island-shaped element region.Type: GrantFiled: July 23, 2002Date of Patent: September 21, 2004Assignee: Kabushiki Kaisha ToshibaInventors: Atsushi Yagishita, Tomohiro Saito, Toshihiko Iinuma
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Publication number: 20040178451Abstract: In a semiconductor device in which the gate electrode of a MISFET formed on a semiconductor substrate is electrically connected to a well region under the channel of the MISFET, the MISFET is formed in an island-shaped element region formed on the semiconductor substrate, and electrical connection between the gate electrode of the MISFET and the well region in the semiconductor substrate is done on the side surface of the island-shaped element region.Type: ApplicationFiled: March 29, 2004Publication date: September 16, 2004Applicant: Kabushiki Kaisha ToshibaInventors: Atsushi Yagishita, Tomohiro Saito, Toshihiko Iinuma
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Publication number: 20040004234Abstract: A method of manufacturing a semiconductor device, includes the steps of forming a disposable gate on a semiconductor substrate in a region where a gate electrode is to be formed, forming a sidewall spacer on a sidewall of the disposable gate, forming a source and drain in the semiconductor substrate using the disposable gate and the sidewall spacer as a mask, forming an interlevel insulating film on the semiconductor substrate so as to cover the disposable gate, planarizing an upper surface of the interlevel insulating film to expose upper surfaces of the disposable gate and the sidewall spacer, removing the disposable gate to form a trench portion having a side surface formed from the sidewall spacer and a bottom surface formed from the semiconductor substrate, depositing a gate insulating film on the semiconductor substrate so as to cover the bottom surface and side surface of the trench portion, forming a gate electrode buried in the trench portion, and removing the sidewall spacer and the gate insulatingType: ApplicationFiled: July 8, 2003Publication date: January 8, 2004Applicant: Kabushiki Kaisha ToshibaInventors: Atsushi Yagishita, Kazuaki Nakajima
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Patent number: 6664592Abstract: A semiconductor device includes a semiconductor substrate, a gate insulator film formed on a bottom surface and a side surface of a groove formed in the semiconductor substrate, a gate electrode having a lower portion buried in the groove on whose bottom and side surface the gate insulator film is formed, and an upper portion protruding a surface of said semiconductor substrate, and source region and a drain region formed on a surface of the semiconductor substrate in such a way as to sandwich the gate electrode. A thickness of the upper portion of the gate electrode protruding the surface of the semiconductor substrate is equal to or greater than twice a thickness of the lower portion of the gate electrode buried in the groove.Type: GrantFiled: December 30, 2002Date of Patent: December 16, 2003Assignee: Kabushiki Kaisha ToshibaInventors: Seiji Inumiya, Tomohiro Saito, Atsushi Yagishita, Katsuhiko Hieda, Toshihiko Iinuma
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Publication number: 20030209761Abstract: A semiconductor device comprises a support layer made of semiconductor, a diffusion layer formed by implanting impurities in a surface layer of the support layer, a buried insulating layer provided on the diffusion layer, an island-like active layer provided on the buried insulating layer, a channel region formed in the active layer, source and drain regions formed in the active layer, sandwiching the channel region, a gate insulating film formed on the channel region, a gate electrode formed on the gate insulating film and on side surfaces of the island-like active layer, and insulated and isolated from the channel, source, and drain regions, and an electrode connected to the active layer.Type: ApplicationFiled: May 13, 2003Publication date: November 13, 2003Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Atsushi Yagishita, Ichiro Mizushima, Tsutomu Sato
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Publication number: 20030183877Abstract: Dummy gate patterns 111, 112 are formed on a silicon active layer 103 of an SOI substrate, and thereafter, these dummy gate patterns 111, 112 are removed to form gate grooves 130, 132. A threshold voltage of each transistor is adjusted by etching a silicon active layer 103 in any one of these gate grooves 130, 132 to reduce a thickness of a portion constituting a channel region. This enables the enhancement of freedom degree and so on in circuit designing according to conditions.Type: ApplicationFiled: March 21, 2003Publication date: October 2, 2003Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Atsushi Yagishita, Tomohiro Saito
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Patent number: 6607952Abstract: A method of manufacturing a semiconductor device, includes the steps of forming a disposable gate on a semiconductor substrate in a region where a gate electrode is to be formed, forming a sidewall spacer on a sidewall of the disposable gate, forming a source and drain in the semiconductor substrate using the disposable gate and the sidewall spacer as a mask, forming an interlevel insulating film on the semiconductor substrate so as to cover the disposable gate, planarizing an upper surface of the interlevel insulating film to expose upper surfaces of the disposable gate and the sidewall spacer, removing the disposable gate to form a trench portion having a side surface formed from the sidewall spacer and a bottom surface formed from the semiconductor substrate, depositing a gate insulating film on the semiconductor substrate so as to cover the bottom surface and side surface of the trench portion, forming a gate electrode buried in the trench portion, and removing the sidewall spacer and the gate insulatingType: GrantFiled: June 30, 2000Date of Patent: August 19, 2003Assignee: Kabushiki Kaisha ToshibaInventors: Atsushi Yagishita, Kazuaki Nakajima
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Publication number: 20030107088Abstract: A method of manufacturing a semiconductor device comprises the steps of forming a first film and a second film on a semiconductor substrate, selectively removing the second film, the first film and a top portion of the semiconductor substrate to form a first groove, burying a first insulator film in the first groove to form an isolation region, patterning the second film surrounded by the isolation region to form a dummy gate layer, doping the semiconductor substrate with an impurity using the dummy gate layer as a mask, forming a second insulator film on the semiconductor substrate surrounded by the dummy gate layer and the first insulator film, removing the dummy gate layer and the first film to form a second groove, forming a gate insulator film on the semiconductor substrate in the second groove, and forming a gate electrode on the gate insulator film in the second groove.Type: ApplicationFiled: December 30, 2002Publication date: June 12, 2003Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Seiji Inumiya, Tomohiro Saito, Atsushi Yagishita, Katsuhiko Hieda, Toshihiko Iinuma
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Patent number: 6515338Abstract: A method of manufacturing semiconductor device comprises the steps of forming a first film and a second film on a semiconductor substrate, selectively removing the second film, the first film and a top portion of the semiconductor substrate to form a first groove, burying a first insulator film in the first groove to form an isolation region, patterning the second film surrounded by the isolation region to form a dummy gate layer, doping the semiconductor substrate with an impurity using the dummy gate layer as a mask, forming a second insulator film on the semiconductor substrate surrounded by the dummy gate layer and the first insulator film, removing the dummy gate layer and the first film to form a second groove, forming a gate insulator film on the semiconductor substrate in the second groove, and forming a gate electrode on the gate insulator film in the second groove.Type: GrantFiled: March 23, 2000Date of Patent: February 4, 2003Assignee: Kabushiki Kaisha ToshibaInventors: Seiji Inumiya, Tomohiro Saito, Atsushi Yagishita, Katsuhiko Hieda, Toshihiko Iinuma
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Publication number: 20020179970Abstract: In a semiconductor device in which the gate electrode of a MISFET formed on a semiconductor substrate is electrically connected to a well region under the channel of the MISFET, the MISFET is formed in an island-shaped element region formed on the semiconductor substrate, and electrical connection between the gate electrode of the MISFET and the well region in the semiconductor substrate is done on the side surface of the island-shaped element region.Type: ApplicationFiled: July 23, 2002Publication date: December 5, 2002Applicant: Kabushiki Kaisha ToshibaInventors: Atsushi Yagishita, Tomohiro Saito, Toshihiko Iinuma
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Publication number: 20020179980Abstract: There is disclosed a semiconductor device in which a device isolating insulating film is formed in a periphery of a device region of a semiconductor silicon substrate device region. A side wall insulating film formed of a silicon nitride film is formed to cover the periphery of a channel region on the silicon substrate. A Ta2O5 film, and a metal gate electrode are formed inside a trench whose side wall is formed of the side wall insulating film. An interlayer insulating film is formed on the device isolating insulating film. A Schottky source/drain formed of silicide is formed on the silicon substrate in a bottom portion of the trench whose side wall is formed of the side wall insulating film and interlayer insulating film. A source/drain electrode is formed on the Schottky source/drain.Type: ApplicationFiled: July 26, 2002Publication date: December 5, 2002Applicant: Kabushiki Kaisha ToshibaInventors: Atsushi Yagishita, Kouji Matsuo
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Patent number: 6465823Abstract: In a semiconductor device in which the gate electrode of a MISFET formed on a semiconductor substrate is electrically connected to a well region under the channel of the MISFET, the MISFET is formed in an island-shaped element region formed on the semiconductor substrate, and electrical connection between the gate electrode of the MISFET and the well region in the semiconductor substrate is done on the side surface of the island-shaped element region.Type: GrantFiled: June 30, 2000Date of Patent: October 15, 2002Assignee: Kabushiki Kaisha ToshibaInventors: Atsushi Yagishita, Tomohiro Saito, Toshihiko Iinuma
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Publication number: 20020045296Abstract: A method of manufacturing a semiconductor device according to this invention is characterized by including the steps of a) forming, on one major surface of a substrate, a gate structure constituted by either one of a dummy gate electrode and a gate electrode having an insulating film at least on bottom surface, and a device isolation insulating film so as to form a first groove divided by the dummy gate electrode or the gate electrode, to position the dummy gate electrode or the gate electrode in the first groove, and to form the gate structure to have an upper surface level not higher than an upper level of the device isolation insulating film, and b) forming source and drain electrodes in the first groove.Type: ApplicationFiled: December 21, 2001Publication date: April 18, 2002Applicant: Kabushika Kaisha ToshibaInventors: Atsushi Yagishita, Kouji Matsuo, Yasushi Akasaka, Kyoichi Suguro, Yoshitaka Tsunashima
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Patent number: 6346438Abstract: A method of manufacturing a semiconductor device according to this invention is characterized by including the steps of a) forming, on one major surface of a substrate, a gate structure constituted by either one of a dummy gate electrode and a gate electrode having an insulating film at least on bottom surface, and a device isolation insulating film so as to form a first groove divided by the dummy gate electrode or the gate electrode, to position the dummy gate electrode or the gate electrode in the first groove, and to form the gate structure to have an upper surface level not higher than an upper level of the device isolation insulating film, and b) forming source and drain electrodes in the first groove.Type: GrantFiled: June 29, 1998Date of Patent: February 12, 2002Assignee: Kabushiki Kaisha ToshibaInventors: Atsushi Yagishita, Kouji Matsuo, Yasushi Akasaka, Kyoichi Suguro, Yoshitaka Tsunashima
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Publication number: 20020011603Abstract: A semiconductor device in which an NMOSFET and a PMOSFET are formed in a silicon substrate, wherein the gate electrodes of NMOSFET and PMOSFET are made of metallic materials, an Si—Ge layer is formed in at least part of the surface regions including the respective channel layers of the NMOSFET and PMOSFET, and the concentration of Ge in the channel layer of the NMOSFET is lower than the concentration of Ge in the channel layer of the PMOSFET.Type: ApplicationFiled: July 19, 2001Publication date: January 31, 2002Applicant: Kabushiki Kaisha ToshibaInventors: Atsushi Yagishita, Kouji Matsuo
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Publication number: 20020011613Abstract: There is disclosed a semiconductor device in which a device isolating insulating film is formed in a periphery of a device region of a semiconductor silicon substrate device region. A side wall insulating film formed of a silicon nitride film is formed to cover the periphery of a channel region on the silicon substrate. A Ta2O5 film, and a metal gate electrode are formed inside a trench whose side wall is formed of the side wall insulating film. An interlayer insulating film is formed on the device isolating insulating film. A Schottky source/drain formed of silicide is formed on the silicon substrate in a bottom portion of the trench whose side wall is formed of the side wall insulating film and interlayer insulating film. A source/drain electrode is formed on the Schottky source/drain.Type: ApplicationFiled: July 11, 2001Publication date: January 31, 2002Applicant: Kabushiki Kaisha ToshibaInventors: Atsushi Yagishita, Kouji Matsuo
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Patent number: 6310367Abstract: A semiconductor device in which an NMOSFET and a PMOSFET are formed in a silicon substrate, wherein the gate electrodes of NMOSFET and PMOSFET are made of metallic materials, an Si—Ge layer is formed in at least part of the surface regions including the respective channel layers of the NMOSFET and PMOSFET, and the concentration of Ge in the channel layer of the NMOSFET is lower than the concentration of Ge in the channel layer of the PMOSFET.Type: GrantFiled: February 22, 2000Date of Patent: October 30, 2001Assignee: Kabushiki Kaisha ToshibaInventors: Atsushi Yagishita, Kouji Matsuo
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Patent number: 6087698Abstract: A semiconductor device includes an underlying layer formed by a first insulation layer, a plurality of island semiconductor layers formed on the first insulation layer, source and drain regions formed in each of the island semiconductor layers, a first gate electrode formed between the source and drain regions and formed on and insulated from the island semiconductor layer, a second insulation layer formed on the sides of the island semiconductor layer and along the periphery of the first gate electrode, the second insulation layer being higher than the surface of the island semiconductor layer and lower than the surface of the first gate electrode, and a second gate electrode formed over both the first gate electrode and the second insulation layer.Type: GrantFiled: March 21, 1997Date of Patent: July 11, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Tomohiro Saito, Minoru Takahashi, Atsushi Yagishita
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Patent number: 6054355Abstract: A method of manufacturing a semiconductor device comprises the steps of forming a first film and a second film on a semiconductor substrate, selectively removing the second film, the first film and a top portion of the semiconductor substrate to form a first groove, burying a first insulator film in the first groove to form an isolation region, patterning the second film surrounded by the isolation region to form a dummy gate layer, doping the semiconductor substrate with an impurity using the dummy gate layer as a mask, forming a second insulator film on the semiconductor substrate surrounded by the dummy gate layer and the first insulator film, removing the dummy gate layer and the first film to form a second groove, forming a gate insulator film on the semiconductor substrate in the second groove, and forming a gate electrode on the gate insulator film in the second groove.Type: GrantFiled: June 29, 1998Date of Patent: April 25, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Seiji Inumiya, Tomohiro Saito, Atsushi Yagishita, Katsuhiko Hieda, Toshihiko Iinuma
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Patent number: 5994756Abstract: A semiconductor substrate having a shallow trench isolation (STI) structure and a method of manufacturing the same are provided, i.e., an isolation substrate in which grooves are selectively formed at predetermined locations of the semiconductor substrate and oxide films using organic silicon source as material are buried in the grooves as buried oxide films. The present invention is characterized in that the buried oxide films are annealed at a predetermined temperature within the range of 1100 to 1350.degree. C. before or after planarization of the semiconductor substrate such that ring structures of more than 5-fold ring and ring structures of less than 4-fold ring are formed at predetermined rates in the buried oxide films. The above annealing allows stress of the oxide film buried in the grooves to be relaxed. Hence, the generation of dislocation is suppressed.Type: GrantFiled: November 20, 1996Date of Patent: November 30, 1999Assignee: Kabushiki Kaisha ToshibaInventors: Kaori Umezawa, Norihiko Tsuchiya, Yoshiaki Matsushita, Hiroyuki Kamijou, Atsushi Yagishita, Tsunehiro Kita