Patents by Inventor Noritaka ISHIHARA
Noritaka ISHIHARA 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: 9595435Abstract: To form an oxide semiconductor film with a low density of localized levels. To improve electric characteristics of a semiconductor device including the oxide semiconductor. After oxygen is added to an oxide film containing In or Ga in contact with an oxide semiconductor film functioning as a channel, heat treatment is performed to make oxygen in the oxide film containing In or Ga transfer to the oxide semiconductor film functioning as a channel, so that the amount of oxygen vacancies in the oxide semiconductor film is reduced. Further, an oxide film containing In or Ga is formed, oxygen is added to the oxide film, an oxide semiconductor film is formed over the oxide film, and then heat treatment is performed.Type: GrantFiled: October 17, 2013Date of Patent: March 14, 2017Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Masashi Tsubuku, Ryosuke Watanabe, Noritaka Ishihara, Masashi Oota
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Patent number: 9583570Abstract: An oxide semiconductor stacked film which does not easily cause a variation in electrical characteristics of a transistor and has high stability is provided. Further, a transistor which includes the oxide semiconductor stacked film in its channel formation region and has stable electrical characteristics is provided. An oxide semiconductor stacked film includes a first oxide semiconductor layer, a second oxide semiconductor layer, and a third oxide semiconductor layer which are sequentially stacked and each of which contains indium, gallium, and zinc. The content percentage of indium in the second oxide semiconductor layer is higher than that in the first oxide semiconductor layer and the third oxide semiconductor layer, and the absorption coefficient of the oxide semiconductor stacked film, which is measured by the CPM, is lower than or equal to 3×10?3/cm in an energy range of 1.5 eV to 2.3 eV.Type: GrantFiled: July 30, 2015Date of Patent: February 28, 2017Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Masashi Tsubuku, Ryosuke Watanabe, Masashi Oota, Noritaka Ishihara, Koki Inoue
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Patent number: 9559174Abstract: 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: March 14, 2016Date of Patent: January 31, 2017Assignee: 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: 20160343733Abstract: To provide a method for manufacturing a semiconductor device including an oxide semiconductor film having conductivity, or a method for manufacturing a semiconductor device including an oxide semiconductor film having a light-transmitting property and conductivity. The method for manufacturing a semiconductor device includes the steps of forming an oxide semiconductor film over a first insulating film, performing first heat treatment in an atmosphere where oxygen contained in the oxide semiconductor film is released, and performing second heat treatment in a hydrogen-containing atmosphere, so that an oxide semiconductor film having conductivity is formed.Type: ApplicationFiled: August 2, 2016Publication date: November 24, 2016Inventors: Masashi OOTA, Noritaka ISHIHARA, Motoki NAKASHIMA, Yoichi KUROSAWA, Shunpei YAMAZAKI, Yasuharu HOSAKA, Toshimitsu OBONAI, Junichi KOEZUKA
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Patent number: 9496413Abstract: Reducing hydrogen concentration in a channel formation region of an oxide semiconductor is important in stabilizing threshold voltage of a transistor including an oxide semiconductor and improving reliability. Hence, hydrogen is attracted from the oxide semiconductor and trapped in a region of an insulating film which overlaps with a source region and a drain region of the oxide semiconductor. Impurities such as argon, nitrogen, carbon, phosphorus, or boron are added to the region of the insulating film which overlaps with the source region and the drain region of the oxide semiconductor, thereby generating a defect. Hydrogen in the oxide semiconductor is attracted to the defect in the insulating film. The defect in the insulating film is stabilized by the presence of hydrogen.Type: GrantFiled: February 25, 2016Date of Patent: November 15, 2016Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Masashi Tsubuku, Yusuke Nonaka, Noritaka Ishihara, Masashi Oota, Hideyuki Kishida
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Publication number: 20160284860Abstract: Defects in an oxide semiconductor film are reduced in a semiconductor device including the oxide semiconductor film. The electrical characteristics of a semiconductor device including an oxide semiconductor film are improved. The reliability of a semiconductor device including an oxide semiconductor film is improved. A semiconductor device including an oxide semiconductor layer; a metal oxide layer in contact with the oxide semiconductor layer, the metal oxide layer including an In-M oxide (M is Ti, Ga, Y, Zr, La, Ce, Nd, or Hf); and a conductive layer in contact with the metal oxide layer, the conductive layer including copper, aluminum, gold, or silver is provided. In the semiconductor device, y/(x+y) is greater than or equal to 0.75 and less than 1 where the atomic ratio of In to M included in the metal oxide layer is In:M=x:y.Type: ApplicationFiled: June 6, 2016Publication date: September 29, 2016Inventors: Noritaka ISHIHARA, Masashi OOTA, Masashi TSUBUKU, Masami JINTYOU, Yukinori SHIMA, Junichi KOEZUKA, Yasuharu HOSAKA, Shunpei YAMAZAKI
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Patent number: 9437428Abstract: To provide a method for manufacturing a semiconductor device including an oxide semiconductor film having conductivity, or a method for manufacturing a semiconductor device including an oxide semiconductor film having a light-transmitting property and conductivity. The method for manufacturing a semiconductor device includes the steps of forming an oxide semiconductor film over a first insulating film, performing first heat treatment in an atmosphere where oxygen contained in the oxide semiconductor film is released, and performing second heat treatment in a hydrogen-containing atmosphere, so that an oxide semiconductor film having conductivity is formed.Type: GrantFiled: November 24, 2014Date of Patent: September 6, 2016Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Masashi Oota, Noritaka Ishihara, Motoki Nakashima, Yoichi Kurosawa, Shunpei Yamazaki, Yasuharu Hosaka, Toshimitsu Obonai, Junichi Koezuka
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Patent number: 9425217Abstract: Defects in an oxide semiconductor film are reduced in a semiconductor device including the oxide semiconductor film. The electrical characteristics of a semiconductor device including an oxide semiconductor film are improved. The reliability of a semiconductor device including an oxide semiconductor film is improved. A semiconductor device including an oxide semiconductor layer; a metal oxide layer in contact with the oxide semiconductor layer, the metal oxide layer including an In-M oxide (M is Ti, Ga, Y, Zr, La, Ce, Nd, or Hf); and a conductive layer in contact with the metal oxide layer, the conductive layer including copper, aluminum, gold, or silver is provided. In the semiconductor device, y/(x+y) is greater than or equal to 0.75 and less than 1 where the atomic ratio of In to M included in the metal oxide layer is In:M=x:y.Type: GrantFiled: September 15, 2014Date of Patent: August 23, 2016Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Noritaka Ishihara, Masashi Oota, Masashi Tsubuku, Masami Jintyou, Yukinori Shima, Junichi Koezuka, Yasuharu Hosaka, Shunpei Yamazaki
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Patent number: 9406760Abstract: 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: February 19, 2015Date of Patent: August 2, 2016Assignee: 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: 20160197193Abstract: 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: ApplicationFiled: March 14, 2016Publication date: July 7, 2016Inventors: Akihisa SHIMOMURA, Yasumasa YAMANE, Yuhei SATO, Takahisa ISHIYAMA, Kenichi OKAZAKI, Chiho KAWANABE, Masashi OOTA, Noritaka ISHIHARA
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Publication number: 20160181432Abstract: Reducing hydrogen concentration in a channel formation region of an oxide semiconductor is important in stabilizing threshold voltage of a transistor including an oxide semiconductor and improving reliability. Hence, hydrogen is attracted from the oxide semiconductor and trapped in a region of an insulating film which overlaps with a source region and a drain region of the oxide semiconductor. Impurities such as argon, nitrogen, carbon, phosphorus, or boron are added to the region of the insulating film which overlaps with the source region and the drain region of the oxide semiconductor, thereby generating a defect. Hydrogen in the oxide semiconductor is attracted to the defect in the insulating film. The defect in the insulating film is stabilized by the presence of hydrogen.Type: ApplicationFiled: February 25, 2016Publication date: June 23, 2016Inventors: Masashi TSUBUKU, Yusuke NONAKA, Noritaka ISHIHARA, Masashi OOTA, Hideyuki KISHIDA
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Publication number: 20160160342Abstract: A method for manufacturing a sputtering target with which an oxide semiconductor film with a small amount of defects can be formed is provided. Alternatively, an oxide semiconductor film with a small amount of defects is formed. A method for manufacturing a sputtering target is provided, which includes the steps of: forming a polycrystalline In-M-Zn oxide (M represents a metal chosen among aluminum, titanium, gallium, yttrium, zirconium, lanthanum, cesium, neodymium, and hafnium) powder by mixing, sintering, and grinding indium oxide, an oxide of the metal, and zinc oxide; forming a mixture by mixing the polycrystalline In-M-Zn oxide powder and a zinc oxide powder; forming a compact by compacting the mixture; and sintering the compact.Type: ApplicationFiled: January 26, 2016Publication date: June 9, 2016Inventors: Shunpei YAMAZAKI, Masashi TSUBUKU, Masashi OOTA, Yoichi KUROSAWA, Noritaka ISHIHARA
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Publication number: 20160155852Abstract: After a sputtering gas is supplied to a deposition chamber, plasma including an ion of the sputtering gas is generated in the vicinity of a target. The ion of the sputtering gas is accelerated and collides with the target, so that flat-plate particles and atoms of the target are separated from the target. The flat-plate particles are deposited with a gap therebetween so that the flat plane faces a substrate. The atom and the aggregate of the atoms separated from the target enter the gap between the deposited flat-plate particles and grow in the plane direction of the substrate to fill the gap. A film is formed over the substrate. After the deposition, heat treatment is performed at high temperature in an oxygen atmosphere, which forms an oxide with a few oxygen vacancies and high crystallinity.Type: ApplicationFiled: November 30, 2015Publication date: June 2, 2016Inventors: Shunpei YAMAZAKI, Haruyuki BABA, Akio SUZUKI, Hiromi SAWAI, Masahiko HAYAKAWA, Noritaka ISHIHARA, Masashi OOTA
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Patent number: 9343578Abstract: A semiconductor device includes an oxide semiconductor layer over a first oxide layer; first source and drain electrodes over the oxide semiconductor layer; second source and drain electrodes over the first source and drain electrodes respectively; a second oxide layer over the first source and drain electrodes; a gate insulating layer over the second source and drain electrodes and the second oxide layer; and a gate electrode overlapping the oxide semiconductor layer with the gate insulating layer provided therebetween. The structure in which the oxide semiconductor layer is sandwiched by the oxide layers can suppress the entry of impurities into the oxide semiconductor layer. The structure in which the oxide semiconductor layer is contacting with the source and drain electrodes can prevent increasing resistance between the source and the drain comparing one in which an oxide semiconductor layer is electrically connected to source and drain electrodes through an oxide layer.Type: GrantFiled: December 27, 2013Date of Patent: May 17, 2016Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Shinpei Matsuda, Masashi Oota, Noritaka Ishihara
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Patent number: 9281407Abstract: Reducing hydrogen concentration in a channel formation region of an oxide semiconductor is important in stabilizing threshold voltage of a transistor including an oxide semiconductor and improving reliability. Hence, hydrogen is attracted from the oxide semiconductor and trapped in a region of an insulating film which overlaps with a source region and a drain region of the oxide semiconductor. Impurities such as argon, nitrogen, carbon, phosphorus, or boron are added to the region of the insulating film which overlaps with the source region and the drain region of the oxide semiconductor, thereby generating a defect. Hydrogen in the oxide semiconductor is attracted to the defect in the insulating film. The defect in the insulating film is stabilized by the presence of hydrogen.Type: GrantFiled: April 30, 2015Date of Patent: March 8, 2016Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Masashi Tsubuku, Yusuke Nonaka, Noritaka Ishihara, Masashi Oota, Hideyuki Kishida
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Patent number: 9267199Abstract: A method for manufacturing a sputtering target with which an oxide semiconductor film with a small amount of defects can be formed is provided. Alternatively, an oxide semiconductor film with a small amount of defects is formed. A method for manufacturing a sputtering target is provided, which includes the steps of: forming a polycrystalline In-M-Zn oxide (M represents a metal chosen among aluminum, titanium, gallium, yttrium, zirconium, lanthanum, cesium, neodymium, and hafnium) powder by mixing, sintering, and grinding indium oxide, an oxide of the metal, and zinc oxide; forming a mixture by mixing the polycrystalline In-M-Zn oxide powder and a zinc oxide powder; forming a compact by compacting the mixture; and sintering the compact.Type: GrantFiled: February 24, 2014Date of Patent: February 23, 2016Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Masashi Tsubuku, Masashi Oota, Yoichi Kurosawa, Noritaka Ishihara
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Publication number: 20150349133Abstract: An oxide semiconductor stacked film which does not easily cause a variation in electrical characteristics of a transistor and has high stability is provided. Further, a transistor which includes the oxide semiconductor stacked film in its channel formation region and has stable electrical characteristics is provided. An oxide semiconductor stacked film includes a first oxide semiconductor layer, a second oxide semiconductor layer, and a third oxide semiconductor layer which are sequentially stacked and each of which contains indium, gallium, and zinc. The content percentage of indium in the second oxide semiconductor layer is higher than that in the first oxide semiconductor layer and the third oxide semiconductor layer, and the absorption coefficient of the oxide semiconductor stacked film, which is measured by the CPM, is lower than or equal to 3×10?3/cm in an energy range of 1.5 eV to 2.3 eV.Type: ApplicationFiled: July 30, 2015Publication date: December 3, 2015Inventors: Shunpei YAMAZAKI, Masashi TSUBUKU, Ryosuke WATANABE, Masashi OOTA, Noritaka ISHIHARA, Koki INOUE
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Publication number: 20150294994Abstract: A metal oxide film including a crystal part and having highly stable physical properties is provided. The size of the crystal part is less than or equal to 10 nm, which allows the observation of circumferentially arranged spots in a nanobeam electron diffraction pattern of the cross section of the metal oxide film when the measurement area is greater than or equal to 5 nm? and less than or equal to 10 nm?.Type: ApplicationFiled: April 16, 2015Publication date: October 15, 2015Inventors: Masahiro TAKAHASHI, Takuya HIROHASHI, Masashi TSUBUKU, Noritaka ISHIHARA, Masashi OOTA
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Publication number: 20150270405Abstract: A metal oxide film including a crystal part and having highly stable physical properties is provided. The size of the crystal part is less than or equal to 10 nm, which allows the observation of circumferentially arranged spots in a nanobeam electron diffraction pattern of the cross section of the metal oxide film when the measurement area is greater than or equal to 5 nm? and less than or equal to 10 nm?.Type: ApplicationFiled: June 9, 2015Publication date: September 24, 2015Inventors: Masahiro TAKAHASHI, Takuya HIROHASHI, Masashi TSUBUKU, Noritaka ISHIHARA, Masashi OOTA
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Publication number: 20150255534Abstract: A method for forming an oxide that can be used as a semiconductor of a transistor or the like is provided. In particular, a method for forming an oxide with fewer defects such as grain boundaries is provided. One embodiment of the present invention is a semiconductor device including an oxide semiconductor, an insulator, and a conductor. The oxide semiconductor includes a region overlapping with the conductor with the insulator therebetween. The oxide semiconductor includes a crystal grain with an equivalent circle diameter of 1 nm or more and a crystal grain with an equivalent circle diameter less than 1 nm.Type: ApplicationFiled: March 3, 2015Publication date: September 10, 2015Inventors: Shunpei YAMAZAKI, Yoshinori YAMADA, Yusuke NONAKA, Masashi OOTA, Yoichi KUROSAWA, Noritaka ISHIHARA, Takashi HAMADA, Mitsuhiro ICHIJO, Yuji EGI