Patents by Inventor Yuhei Sato
Yuhei Sato 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: 10249651Abstract: A semiconductor device using an oxide semiconductor is provided with stable electric characteristics to improve the reliability. In a manufacturing process of a transistor including an oxide semiconductor film, an oxide semiconductor film containing a crystal having a c-axis which is substantially perpendicular to a top surface thereof (also called a first crystalline oxide semiconductor film) is formed; oxygen is added to the oxide semiconductor film to amorphize at least part of the oxide semiconductor film, so that an amorphous oxide semiconductor film containing an excess of oxygen is formed; an aluminum oxide film is formed over the amorphous oxide semiconductor film; and heat treatment is performed thereon to crystallize at least part of the amorphous oxide semiconductor film, so that an oxide semiconductor film containing a crystal having a c-axis which is substantially perpendicular to a top surface thereof (also called a second crystalline oxide semiconductor film) is formed.Type: GrantFiled: March 5, 2018Date of Patent: April 2, 2019Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Junichi Koezuka, Naoto Yamade, Yuhei Sato, Yutaka Okazaki, Shunpei Yamazaki
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Publication number: 20190035937Abstract: A semiconductor device having a reduced amount of oxygen vacancy in a channel formation region of an oxide semiconductor is provided. Further, a semiconductor device which includes an oxide semiconductor and has improved electric characteristics is provided. Furthermore, a methods for manufacturing the semiconductor device is provided. An oxide semiconductor film is formed; a conductive film is formed over the oxide semiconductor film at the same time as forming a low-resistance region between the oxide semiconductor film and the conductive film; the conductive film is processed to form a source electrode and a drain electrode; and oxygen is added to the low-resistance region between the source electrode and the drain electrode, so that a channel formation region having a higher resistance than the low-resistance region is formed and a first low-resistance region and a second low-resistance region between which the channel formation region is positioned are formed.Type: ApplicationFiled: July 2, 2018Publication date: January 31, 2019Inventors: Shunpei YAMAZAKI, Hideomi SUZAWA, Tetsuhiro TANAKA, Hirokazu WATANABE, Yuhei SATO, Yasumasa YAMANE, Daisuke MATSUBAYASHI
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Patent number: 10103271Abstract: A transistor having high field-effect mobility is provided. A transistor having stable electrical characteristics is provided. A transistor having small current in an off state (in a non-conductive state) is provided. A semiconductor device including such a transistor is provided. A first electrode is formed over a substrate, a first insulating layer is formed adjacent to a side surface of the first electrode, and a second insulating layer is formed to cover the first insulating layer and be in contact with at least part of a surface of the first electrode. The surface of the first electrode is formed of a conductive material that does not easily transmit an impurity element. The second insulating layer is formed of an insulating material that does not easily transmit an impurity element. An oxide semiconductor layer is formed over the first electrode with a third insulating layer provided therebetween.Type: GrantFiled: January 24, 2018Date of Patent: October 16, 2018Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Hideomi Suzawa, Tetsuhiro Tanaka, Yuhei Sato, Sachiaki Tezuka, Shunpei Yamazaki
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Publication number: 20180277392Abstract: In a manufacturing process of a transistor including an oxide semiconductor film, oxygen doping treatment is performed on the oxide semiconductor film, and then heat treatment is performed on the oxide semiconductor film and an aluminum oxide film provided over the oxide semiconductor film. Consequently, an oxide semiconductor film which includes a region containing more oxygen than a stoichiometric composition is formed. The transistor formed using the oxide semiconductor film can have high reliability because the amount of change in the threshold voltage of the transistor by a bias-temperature stress test (BT test) is reduced.Type: ApplicationFiled: May 29, 2018Publication date: September 27, 2018Inventors: Shunpei YAMAZAKI, Yuhei SATO, Keiji SATO, Tetsunori MARUYAMA, Junichi KOEZUKA
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Publication number: 20180261633Abstract: A semiconductor device using an oxide semiconductor is provided with stable electric characteristics to improve the reliability. In a manufacturing process of a transistor including an oxide semiconductor film, an oxide semiconductor film containing a crystal having a c-axis which is substantially perpendicular to a top surface thereof (also called a first crystalline oxide semiconductor film) is formed; oxygen is added to the oxide semiconductor film to amorphize at least part of the oxide semiconductor film, so that an amorphous oxide semiconductor film containing an excess of oxygen is formed; an aluminum oxide film is formed over the amorphous oxide semiconductor film; and heat treatment is performed thereon to crystallize at least part of the amorphous oxide semiconductor film, so that an oxide semiconductor film containing a crystal having a c-axis which is substantially perpendicular to a top surface thereof (also called a second crystalline oxide semiconductor film) is formed.Type: ApplicationFiled: March 5, 2018Publication date: September 13, 2018Inventors: Junichi KOEZUKA, Naoto YAMADE, Yuhei SATO, Yutaka OKAZAKI, Shunpei YAMAZAKI
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Patent number: 10050132Abstract: A change in electrical characteristics is suppressed and reliability in a semiconductor device using a transistor including an oxide semiconductor is improved. One feature resides in forming an oxide semiconductor film over an oxygen-introduced insulating film, and then forming the source and drain electrodes with an antioxidant film thereunder. Here, in the antioxidant film, the width of a region overlapping with the source and drain electrodes is longer than the width of a region not overlapping with them. The transistor formed as such has less defects in the channel region, which will improve reliability of the semiconductor device.Type: GrantFiled: July 31, 2017Date of Patent: August 14, 2018Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Akihisa Shimomura, Yasumasa Yamane, Yuhei Sato, Tetsuhiro Tanaka, Masashi Tsubuku, Toshihiko Takeuchi, Ryo Tokumaru, Mitsuhiro Ichijo, Satoshi Toriumi, Takashi Ohtsuki, Toshiya Endo
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Patent number: 10043913Abstract: A semiconductor device with favorable electrical characteristics is provided. In an oxide semiconductor film, a plurality of electron diffraction patterns are observed in such a manner that a surface over which the oxide semiconductor film is formed is irradiated with an electron beam having a probe diameter whose half-width is 1 nm while the position of the film and the position of the electron beam are relatively moved. The electron diffraction patterns include 50 or more electron diffraction patterns observed in different areas. The sum of the percentage of first electron diffraction patterns and the percentage of second electron diffraction patterns accounts for 100%. The first electron diffraction patterns account for 50% or more. The first electron diffraction pattern includes observation points that are not symmetry or observation points disposed in a circular pattern. The second electron diffraction pattern includes observation points corresponding to the vertices of a hexagon.Type: GrantFiled: March 17, 2015Date of Patent: August 7, 2018Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Akihisa Shimomura, Yuhei Sato, Yasumasa Yamane, Shunpei Yamazaki, Kenichi Okazaki, Chiho Kawanabe
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Patent number: 10032928Abstract: Favorable electrical characteristics are given to a semiconductor device. Furthermore, a semiconductor device having high reliability is provided. One embodiment of the present invention is an oxide semiconductor film having a plurality of electron diffraction patterns which are observed in such a manner that a surface where the oxide semiconductor film is formed is irradiated with an electron beam having a probe diameter whose half-width is 1 nm. The plurality of electron diffraction patterns include 50 or more electron diffraction patterns which are observed in different areas, the sum of the percentage of first electron diffraction patterns and the percentage of second electron diffraction patterns accounts for 100%, the first electron diffraction patterns account for 90% or more, the first electron diffraction pattern includes observed points which indicates that a c-axis is oriented in a direction substantially perpendicular to the surface where the oxide semiconductor film is formed.Type: GrantFiled: January 27, 2017Date of Patent: July 24, 2018Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Akihisa Shimomura, Yasumasa Yamane, Yuhei Sato, Takahisa Ishiyama, Kenichi Okazaki, Chiho Kawanabe, Masashi Oota, Noritaka Ishihara
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Publication number: 20180182894Abstract: To provide a highly reliable semiconductor device manufactured by giving stable electric characteristics to a semiconductor device including an oxide semiconductor. In a manufacturing process of a transistor, an oxide semiconductor layer, a source electrode layer, a drain electrode layer, a gate insulating film, a gate electrode layer, and an aluminum oxide film are formed in this order, and then heat treatment is performed on the oxide semiconductor layer and the aluminum oxide film, whereby an oxide semiconductor layer from which an impurity containing a hydrogen atom is removed and which includes a region containing oxygen more than the stoichiometric proportion is formed. In addition, when the aluminum oxide film is formed, entry and diffusion of water or hydrogen into the oxide semiconductor layer from the air due to heat treatment in a manufacturing process of a semiconductor device or an electronic appliance including the transistor can be prevented.Type: ApplicationFiled: February 26, 2018Publication date: June 28, 2018Inventors: Yuhei SATO, Keiji SATO, Toshinari SASAKI, Tetsunori MARUYAMA, Atsuo ISOBE, Tsutomu MURAKAWA, Sachiaki TEZUKA
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Patent number: 10008588Abstract: The amount of water and hydrogen contained in an oxide semiconductor film is reduced, and oxygen is supplied sufficiently from a base film to the oxide semiconductor film in order to reduce oxygen deficiencies. A stacked base film is formed, a first heat treatment is performed, an oxide semiconductor film is formed over and in contact with the stacked base film, and a second heat treatment is performed. In the stacked base film, a first base film and a second base film are stacked in this order. The first base film is an insulating oxide film from which oxygen is released by heating. The second base film is an insulating metal oxide film. An oxygen diffusion coefficient of the second base film is smaller than that of the first base film.Type: GrantFiled: December 26, 2014Date of Patent: June 26, 2018Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Yuki Imoto, Yuhei Sato
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Patent number: 10002775Abstract: In a manufacturing process of a transistor including an oxide semiconductor film, oxygen doping treatment is performed on the oxide semiconductor film, and then heat treatment is performed on the oxide semiconductor film and an aluminum oxide film provided over the oxide semiconductor film. Consequently, an oxide semiconductor film which includes a region containing more oxygen than a stoichiometric composition is formed. The transistor formed using the oxide semiconductor film can have high reliability because the amount of change in the threshold voltage of the transistor by a bias-temperature stress test (BT test) is reduced.Type: GrantFiled: June 1, 2016Date of Patent: June 19, 2018Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Yuhei Sato, Keiji Sato, Tetsunori Maruyama, Junichi Koezuka
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Publication number: 20180151743Abstract: To provide a transistor having a high on-state current. A semiconductor device includes a first insulator containing excess oxygen, a first oxide semiconductor over the first insulator, a second oxide semiconductor over the first oxide semiconductor, a first conductor and a second conductor which are over the second oxide semiconductor and are separated from each other, a third oxide semiconductor in contact with side surfaces of the first oxide semiconductor, a top surface and side surfaces of the second oxide semiconductor, a top surface of the first conductor, and a top surface of the second conductor, a second insulator over the third oxide semiconductor, and a third conductor facing a top surface and side surfaces of the second oxide semiconductor with the second insulator and the third oxide semiconductor therebetween. The first oxide semiconductor has a higher oxygen-transmitting property than the third oxide semiconductor.Type: ApplicationFiled: January 9, 2018Publication date: May 31, 2018Inventors: Shunpei YAMAZAKI, Akihisa SHIMOMURA, Yuhei SATO, Yasumasa YAMANE, Yoshitaka YAMAMOTO, Hideomi SUZAWA, Tetsuhiro TANAKA, Yutaka OKAZAKI, Naoki OKUNO, Takahisa ISHIYAMA
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Publication number: 20180151750Abstract: A transistor having high field-effect mobility is provided. A transistor having stable electrical characteristics is provided. A transistor having small current in an off state (in a non-conductive state) is provided. A semiconductor device including such a transistor is provided. A first electrode is formed over a substrate, a first insulating layer is formed adjacent to a side surface of the first electrode, and a second insulating layer is formed to cover the first insulating layer and be in contact with at least part of a surface of the first electrode. The surface of the first electrode is formed of a conductive material that does not easily transmit an impurity element. The second insulating layer is formed of an insulating material that does not easily transmit an impurity element. An oxide semiconductor layer is formed over the first electrode with a third insulating layer provided therebetween.Type: ApplicationFiled: January 24, 2018Publication date: May 31, 2018Inventors: Hideomi SUZAWA, Tetsuhiro TANAKA, Yuhei SATO, Sachiaki TEZUKA, Shunpei YAMAZAKI
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Patent number: 9960279Abstract: Hydrogen concentration and oxygen vacancies in an oxide semiconductor film are reduced. Reliability of a semiconductor device which includes a transistor using an oxide semiconductor film is improved. One embodiment of the present invention is a semiconductor device which includes a base insulating film; an oxide semiconductor film formed over the base insulating film; a gate insulating film formed over the oxide semiconductor film; and a gate electrode overlapping with the oxide semiconductor film with the gate insulating film provided therebetween. The base insulating film shows a signal at a g value of 2.01 by electron spin resonance. The oxide semiconductor film does not show a signal at a g value of 1.93 by electron spin resonance.Type: GrantFiled: December 4, 2014Date of Patent: May 1, 2018Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Toshinari Sasaki, Kosei Noda, Yuhei Sato, Yuta Endo
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Patent number: 9960278Abstract: To provide a highly reliable semiconductor device manufactured by giving stable electric characteristics to a semiconductor device including an oxide semiconductor. In a manufacturing process of a transistor, an oxide semiconductor layer, a source electrode layer, a drain electrode layer, a gate insulating film, a gate electrode layer, and an aluminum oxide film are formed in this order, and then heat treatment is performed on the oxide semiconductor layer and the aluminum oxide film, whereby an oxide semiconductor layer from which an impurity containing a hydrogen atom is removed and which includes a region containing oxygen more than the stoichiometric proportion is formed. In addition, when the aluminum oxide film is formed, entry and diffusion of water or hydrogen into the oxide semiconductor layer from the air due to heat treatment in a manufacturing process of a semiconductor device or an electronic appliance including the transistor can be prevented.Type: GrantFiled: April 2, 2012Date of Patent: May 1, 2018Inventors: Yuhei Sato, Keiji Sato, Toshinari Sasaki, Tetsunori Maruyama, Atsuo Isobe, Tsutomu Murakawa, Sachiaki Tezuka
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Patent number: 9911767Abstract: A semiconductor device using an oxide semiconductor is provided with stable electric characteristics to improve the reliability. In a manufacturing process of a transistor including an oxide semiconductor film, an oxide semiconductor film containing a crystal having a c-axis which is substantially perpendicular to a top surface thereof (also called a first crystalline oxide semiconductor film) is formed; oxygen is added to the oxide semiconductor film to amorphize at least part of the oxide semiconductor film, so that an amorphous oxide semiconductor film containing an excess of oxygen is formed; an aluminum oxide film is formed over the amorphous oxide semiconductor film; and heat treatment is performed thereon to crystallize at least part of the amorphous oxide semiconductor film, so that an oxide semiconductor film containing a crystal having a c-axis which is substantially perpendicular to a top surface thereof (also called a second crystalline oxide semiconductor film) is formed.Type: GrantFiled: January 5, 2017Date of Patent: March 6, 2018Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Junichi Koezuka, Naoto Yamade, Yuhei Sato, Yutaka Okazaki, Shunpei Yamazaki
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Patent number: 9899535Abstract: To provide a transistor with stable electrical characteristics, a transistor with a low off-state current, a transistor with a high on-state current, a semiconductor device including the transistor, or a durable semiconductor device. The semiconductor device includes a first transistor using silicon, an aluminum oxide film over the first transistor, and a second transistor using an oxide semiconductor over the aluminum oxide film. The oxide semiconductor has a lower hydrogen concentration than silicon.Type: GrantFiled: October 13, 2016Date of Patent: February 20, 2018Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Tetsuhiro Tanaka, Hideomi Suzawa, Yasumasa Yamane, Yuhei Sato, Sachiaki Tezuka
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Patent number: 9887295Abstract: A transistor having high field-effect mobility is provided. A transistor having stable electrical characteristics is provided. A transistor having small current in an off state (in a non-conductive state) is provided. A semiconductor device including such a transistor is provided. A first electrode is formed over a substrate, a first insulating layer is formed adjacent to a side surface of the first electrode, and a second insulating layer is formed to cover the first insulating layer and be in contact with at least part of a surface of the first electrode. The surface of the first electrode is formed of a conductive material that does not easily transmit an impurity element. The second insulating layer is formed of an insulating material that does not easily transmit an impurity element. An oxide semiconductor layer is formed over the first electrode with a third insulating layer provided therebetween.Type: GrantFiled: September 20, 2016Date of Patent: February 6, 2018Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Hideomi Suzawa, Tetsuhiro Tanaka, Yuhei Sato, Sachiaki Tezuka, Shunpei Yamazaki
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Patent number: 9882059Abstract: To provide a transistor having a high on-state current. A semiconductor device includes a first insulator containing excess oxygen, a first oxide semiconductor over the first insulator, a second oxide semiconductor over the first oxide semiconductor, a first conductor and a second conductor which are over the second oxide semiconductor and are separated from each other, a third oxide semiconductor in contact with side surfaces of the first oxide semiconductor, a top surface and side surfaces of the second oxide semiconductor, a top surface of the first conductor, and a top surface of the second conductor, a second insulator over the third oxide semiconductor, and a third conductor facing a top surface and side surfaces of the second oxide semiconductor with the second insulator and the third oxide semiconductor therebetween. The first oxide semiconductor has a higher oxygen-transmitting property than the third oxide semiconductor.Type: GrantFiled: December 16, 2014Date of Patent: January 30, 2018Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Akihisa Shimomura, Yuhei Sato, Yasumasa Yamane, Yoshitaka Yamamoto, Hideomi Suzawa, Tetsuhiro Tanaka, Yutaka Okazaki, Naoki Okuno, Takahisa Ishiyama
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Publication number: 20170352746Abstract: A change in electrical characteristics is suppressed and reliability in a semiconductor device using a transistor including an oxide semiconductor is improved. Oxygen is introduced into a surface of an insulating film, and then, an oxide semiconductor, a layer which is capable of blocking oxygen, a gate insulating film, and other films which composes a transistor are formed. For at least one of the first gate insulating film and the insulating film, three signals in Electron Spin Resonance Measurement are each observed in a certain range of g-factor. Reducing the sum of the spin densities of the signals will improve reliability of the semiconductor device.Type: ApplicationFiled: July 31, 2017Publication date: December 7, 2017Inventors: Shunpei YAMAZAKI, Akihisa SHIMOMURA, Yasumasa YAMANE, Yuhei SATO, Tetsuhiro TANAKA, Masashi TSUBUKU, Toshihiko TAKEUCHI, Ryo TOKUMARU, Mitsuhiro ICHIJO, Satoshi TORIUMI, Takashi OHTSUKI, Toshiya ENDO