Patents by Inventor Ryo Tokumaru
Ryo Tokumaru 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: 9496411Abstract: A method for manufacturing a semiconductor device includes the steps of forming a first insulating film over a first gate electrode over a substrate while heated at a temperature higher than or equal to 450° C. and lower than the strain point of the substrate, forming a first oxide semiconductor film over the first insulating film, adding oxygen to the first oxide semiconductor film and then forming a second oxide semiconductor film over the first oxide semiconductor film, and performing heat treatment so that part of oxygen contained in the first oxide semiconductor film is transferred to the second oxide semiconductor film.Type: GrantFiled: May 22, 2015Date of Patent: November 15, 2016Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Tetsuhiro Tanaka, Masayuki Sakakura, Ryo Tokumaru, Yasumasa Yamane, Yuhei Sato
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Patent number: 9478664Abstract: A change in electrical characteristics is suppressed and reliability in a semiconductor device using a transistor including an oxide semiconductor is improved. The semiconductor device includes an oxide semiconductor film over an insulating surface, an antioxidant film over the insulating surface and the oxide semiconductor film, a pair of electrodes in contact with the antioxidant film, a gate insulating film over the pair of electrodes, and a gate electrode which is over the gate insulating film and overlaps with the oxide semiconductor film. In the antioxidant film, a width of a region overlapping with the pair of electrodes is longer than a width of a region not overlapping with the pair of electrodes.Type: GrantFiled: December 18, 2014Date of Patent: October 25, 2016Assignee: 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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Publication number: 20160284856Abstract: A semiconductor device including a miniaturized transistor is provided. The semiconductor device includes a first insulator, a second insulator, a semiconductor, and a conductor. The semiconductor is over the first insulator. The second insulator is over the semiconductor. The conductor is over the second insulator. The semiconductor includes a first region, a second region, and a third region. The first region is a region where the semiconductor overlaps with the conductor. Each of the second region and the third region is a region where the semiconductor does not overlap with the conductor. The second region and the third region each have a region with a spinel crystal structure.Type: ApplicationFiled: March 22, 2016Publication date: September 29, 2016Inventors: Akihisa SHIMOMURA, Tetsuhiro TANAKA, Masayuki KIMURA, Ryo TOKUMARU, Daisuke MATSUBAYASHI, Yasumasa YAMANE
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Publication number: 20160254386Abstract: Provided is a transistor with stable electrical characteristics. Provided is a semiconductor device including an oxide semiconductor over a substrate, a first conductor in contact with a top surface of the oxide semiconductor, a second conductor in contact with the top surface of the oxide semiconductor, a first insulator over the first and second conductors and in contact with the top surface of the oxide semiconductor, a second insulator over the first insulator, a third conductor over the second insulator, and a third insulator over the third conductor. The third conductor overlaps with the first conductor with the first and second insulators positioned therebetween, and overlaps with the second conductor with the first and second insulators positioned therebetween. The first insulator contains oxygen. The second insulator transmits less oxygen than the first insulator. The third insulator transmits less oxygen than the first insulator.Type: ApplicationFiled: February 19, 2016Publication date: September 1, 2016Inventors: Shunpei YAMAZAKI, Tetsuhiro TANAKA, Akihisa SHIMOMURA, Ryo TOKUMARU, Yasumasa YAMANE, Yuhei SATO, Naoki OKUNO, Motoki NAKASHIMA
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Patent number: 9431541Abstract: To give favorable electrical characteristics to a semiconductor device. To provide a semiconductor device in which a change in electrical characteristics is suppressed. To provide a highly reliable semiconductor device. The semiconductor device includes a first insulating layer; a second insulating layer including an opening portion, over the first insulating layer; a semiconductor layer over the first insulating layer; a source electrode and a drain electrode that are apart from each other in a region overlapping with the semiconductor layer; a gate electrode overlapping with the semiconductor layer; and a gate insulating layer between the semiconductor layer and the gate electrode. The first insulating layer includes oxide, and the opening portion of the second insulating layer is positioned inside the semiconductor layer when seen from a top surface side and at least part of the opening portion is provided to overlap with the gate electrode.Type: GrantFiled: August 12, 2014Date of Patent: August 30, 2016Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Ryo Tokumaru, Kensuke Yoshizumi
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Publication number: 20160172500Abstract: A transistor with stable electrical characteristics is provided. The transistor includes a first insulator over a substrate; first to third oxide insulators over the first insulator; a second insulator over the third oxide insulator; a first conductor over the second insulator; and a third insulator over the first conductor. An energy level of a conduction band minimum of each of the first and second oxide insulators is closer to a vacuum level than that of the oxide semiconductor is. An energy level of a conduction band minimum of the third oxide insulator is closer to the vacuum level than that of the second oxide insulator is. The first insulator contains oxygen. The number of oxygen molecules released from the first insulator measured by thermal desorption spectroscopy is greater than or equal to 1E14 molecules/cm2 and less than or equal to 1E16 molecules/cm2.Type: ApplicationFiled: December 9, 2015Publication date: June 16, 2016Applicant: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Tetsuhiro TANAKA, Akihisa SHIMOMURA, Yasumasa YAMANE, Ryo TOKUMARU, Yuhei SATO, Kazuhiro TSUTSUI
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Publication number: 20160056043Abstract: To provide a semiconductor device including an oxide semiconductor layer with high and stable electrical characteristics, the semiconductor device is manufactured by forming a first insulating layer, forming oxide over the first insulating layer and then removing the oxide n times (n is a natural number), forming an oxide semiconductor layer over the first insulating layer, forming a second insulating layer over the oxide semiconductor layer, and forming a conductive layer over the second insulating layer. Alternatively, the semiconductor device is manufactured by forming the oxide semiconductor layer over the first insulating layer, forming the second insulating layer over the oxide semiconductor layer, forming the oxide over the second insulating layer and then removing the oxide n times (n is a natural number), and forming the conductive layer over the second insulating layer.Type: ApplicationFiled: August 18, 2015Publication date: February 25, 2016Applicant: Semiconductor Energy Laboratory Co., Ltd.Inventors: Tetsuhiro TANAKA, Ryo TOKUMARU, Yasumasa YAMANE, Akihisa SHIMOMURA, Naoki OKUNO
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Publication number: 20150340505Abstract: A method for manufacturing a semiconductor device includes the steps of forming a first insulating film over a first gate electrode over a substrate while heated at a temperature higher than or equal to 450° C. and lower than the strain point of the substrate, forming a first oxide semiconductor film over the first insulating film, adding oxygen to the first oxide semiconductor film and then forming a second oxide semiconductor film over the first oxide semiconductor film, and performing heat treatment so that part of oxygen contained in the first oxide semiconductor film is transferred to the second oxide semiconductor film.Type: ApplicationFiled: May 22, 2015Publication date: November 26, 2015Inventors: Shunpei YAMAZAKI, Tetsuhiro TANAKA, Masayuki SAKAKURA, Ryo TOKUMARU, Yasumasa YAMANE, Yuhei SATO
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Publication number: 20150179810Abstract: A change in electrical characteristics is suppressed and reliability in a semiconductor device using a transistor including an oxide semiconductor is improved. The semiconductor device includes an oxide semiconductor film over an insulating surface, an antioxidant film over the insulating surface and the oxide semiconductor film, a pair of electrodes in contact with the antioxidant film, a gate insulating film over the pair of electrodes, and a gate electrode which is over the gate insulating film and overlaps with the oxide semiconductor film. In the antioxidant film, a width of a region overlapping with the pair of electrodes is longer than a width of a region not overlapping with the pair of electrodes.Type: ApplicationFiled: December 18, 2014Publication date: June 25, 2015Inventors: 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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Publication number: 20150053972Abstract: To give favorable electrical characteristics to a semiconductor device. To provide a semiconductor device in which a change in electrical characteristics is suppressed. To provide a highly reliable semiconductor device. The semiconductor device includes a first insulating layer; a second insulating layer including an opening portion, over the first insulating layer; a semiconductor layer over the first insulating layer; a source electrode and a drain electrode that are apart from each other in a region overlapping with the semiconductor layer; a gate electrode overlapping with the semiconductor layer; and a gate insulating layer between the semiconductor layer and the gate electrode. The first insulating layer includes oxide, and the opening portion of the second insulating layer is positioned inside the semiconductor layer when seen from a top surface side and at least part of the opening portion is provided to overlap with the gate electrode.Type: ApplicationFiled: August 12, 2014Publication date: February 26, 2015Inventors: Ryo Tokumaru, Kensuke Yoshizumi
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Patent number: 8916425Abstract: A seed crystal including mixed phase grains having high crystallinity with a low grain density is formed under a first condition, and a microcrystalline semiconductor film is formed over the seed crystal under a second condition which allows the mixed phase grains in the seed crystal to grow to fill a space between the mixed phase grains. In the first condition, the flow rate of hydrogen is 50 times or greater and 1000 times or less that of a deposition gas containing silicon or germanium, and the pressure in a process chamber is greater than 1333 Pa and 13332 Pa or less. In the second condition, the flow rate of hydrogen is 100 times or greater and 2000 times or less that of a deposition gas containing silicon or germanium, and the pressure in the process chamber is 1333 Pa or greater and 13332 Pa or less.Type: GrantFiled: July 18, 2011Date of Patent: December 23, 2014Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Ryota Tajima, Tetsuhiro Tanaka, Takashi Ohtsuki, Ryo Tokumaru, Yuji Egi, Erika Kato, Miyako Morikubo
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Patent number: 8828859Abstract: A microcrystalline semiconductor film is formed over a substrate using a plasma CVD apparatus which includes a reaction chamber in such a manner that a deposition gas and hydrogen are supplied to the reaction chamber in which the substrate is set between a first electrode and a second electrode; and plasma is generated in the reaction chamber by supplying high-frequency power to the first electrode. Note that the plasma density in a region overlapping with an end portion of the substrate in a region where the plasma is generated is set to be higher than that in a region which is positioned more on the inside than the region overlapping with the end portion of the substrate, so that the microcrystalline semiconductor film is formed over a region which is positioned more on the inside than the end portion of the substrate.Type: GrantFiled: February 8, 2012Date of Patent: September 9, 2014Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Tetsuhiro Tanaka, Ryo Tokumaru, Takashi Ohtsuki, Ryota Tajima, Erika Kato
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Patent number: 8629445Abstract: Provided are a semiconductor device with less leakage current is reduced, a semiconductor device with both of high field effect mobility and low leakage current, an electronic appliance with low power consumption, and a manufacturing method of a semiconductor device in which leakage current can be reduced without an increase in the number of masks. The side surface of a semiconductor layer formed of a semiconductor film having high carrier mobility is not in contact with any of a source electrode and a drain electrode. Further, such a transistor structure is formed without an increase in the number of photomasks and can be applied to an electronic appliance.Type: GrantFiled: February 16, 2012Date of Patent: January 14, 2014Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Tetsuhiro Tanaka, Ryo Tokumaru
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Patent number: 8557687Abstract: A microcrystalline semiconductor film having a high crystallinity is formed. Further, a thin film transistor having preferable electric characteristics and high reliability and a display device including the thin film transistor are manufactured with high mass productivity. A step in which a deposition gas containing silicon or germanium is introduced at a first flow rate and a step in which the deposition gas containing silicon or germanium is introduced at a second flow rate are repeated while hydrogen is introduced at a fixed rate, so that the hydrogen and the deposition gas containing silicon or germanium are mixed, and a high-frequency power is supplied. Therefore, a microcrystalline semiconductor film is formed over a substrate.Type: GrantFiled: July 16, 2010Date of Patent: October 15, 2013Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Ryota Tajima, Tetsuhiro Tanaka, Ryo Tokumaru, Hidekazu Miyairi, Mitsuhiro Ichijo, Taichi Nozawa
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Patent number: 8476638Abstract: An object of the present invention is to provide a technique for manufacturing a dense crystalline semiconductor film without a cavity between crystal grains. A plasma region is formed between a first electrode and a second electrode by supplying high-frequency power of 60 MHz or less to the first electrode under a condition where a pressure of a reactive gas in a reaction chamber of a plasma CVD apparatus is set to 450 Pa to 13332 Pa, and a distance between the first electrode and the second electrode of the plasma CVD apparatus is set to 1 mm to 20 mm; crystalline deposition precursors are formed in a gas phase including the plasma region; a crystal nucleus of 5 nm to 15 nm is formed by depositing the deposition precursors; and a microcrystalline semiconductor film is formed by growing a crystal from the crystal nucleus.Type: GrantFiled: July 17, 2012Date of Patent: July 2, 2013Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Satoshi Toriumi, Ryota Tajima, Takashi Ohtsuki, Tetsuhiro Tanaka, Ryo Tokumaru, Mitsuhiro Ichijo, Kazutaka Kuriki, Tomokazu Yokoi, Toshiya Endo, Shunpei Yamazaki
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Publication number: 20120304932Abstract: An object of the present invention is to provide a technique for manufacturing a dense crystalline semiconductor film without a cavity between crystal grains. A plasma region is formed between a first electrode and a second electrode by supplying high-frequency power of 60 MHz or less to the first electrode under a condition where a pressure of a reactive gas in a reaction chamber of a plasma CVD apparatus is set to 450 Pa to 13332 Pa, and a distance between the first electrode and the second electrode of the plasma CVD apparatus is set to 1 mm to 20 mm; crystalline deposition precursors are formed in a gas phase including the plasma region; a crystal nucleus of 5 nm to 15 nm is formed by depositing the deposition precursors; and a microcrystalline semiconductor film is formed by growing a crystal from the crystal nucleus.Type: ApplicationFiled: July 17, 2012Publication date: December 6, 2012Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.Inventors: Satoshi Toriumi, Ryota Tajima, Takashi Ohtsuki, Tetsuhiro Tanaka, Ryo Tokumaru, Mitsuhiro Ichijo, Kazutaka Kuriki, Tomokazu Yokoi, Toshiya Endo, Shunpei Yamazaki
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Patent number: 8252669Abstract: An object of one embodiment of the present invention is to provide a technique for manufacturing a dense crystalline semiconductor film (e.g., a microcrystalline semiconductor film) without a cavity between crystal grains. A plasma region is formed between a first electrode and a second electrode by supplying high-frequency power of 60 MHz or less to the first electrode under a condition where a pressure of a reactive gas in a reaction chamber of a plasma CVD apparatus is set to 450 Pa to 13332 Pa, and a distance between the first electrode and the second electrode of the plasma CVD apparatus is set to 1 mm to 20 mm; crystalline deposition precursors are formed in a gas phase including the plasma region; a crystal nucleus of 5 nm to 15 nm is formed by depositing the deposition precursors; and a microcrystalline semiconductor film is formed by growing a crystal from the crystal nucleus.Type: GrantFiled: August 20, 2010Date of Patent: August 28, 2012Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Satoshi Toriumi, Ryota Tajima, Takashi Ohtsuki, Tetsuhiro Tanaka, Ryo Tokumaru, Mitsuhiro Ichijo, Kazutaka Kuriki, Tomokazu Yokoi, Toshiya Endo, Shunpei Yamazaki
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Publication number: 20120211809Abstract: Provided are a semiconductor device with less leakage current is reduced, a semiconductor device with both of high field effect mobility and low leakage current, an electronic appliance with low power consumption, and a manufacturing method of a semiconductor device in which leakage current can be reduced without an increase in the number of masks. The side surface of a semiconductor layer formed of a semiconductor film having high carrier mobility is not in contact with any of a source electrode and a drain electrode. Further, such a transistor structure is formed without an increase in the number of photomasks and can be applied to an electronic appliance.Type: ApplicationFiled: February 16, 2012Publication date: August 23, 2012Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.Inventors: Tetsuhiro Tanaka, Ryo Tokumaru
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Publication number: 20120208360Abstract: A microcrystalline semiconductor film is formed over a substrate using a plasma CVD apparatus which includes a reaction chamber in such a manner that a deposition gas and hydrogen are supplied to the reaction chamber in which the substrate is set between a first electrode and a second electrode; and plasma is generated in the reaction chamber by supplying high-frequency power to the first electrode. Note that the plasma density in a region overlapping with an end portion of the substrate in a region where the plasma is generated is set to be higher than that in a region which is positioned more on the inside than the region overlapping with the end portion of the substrate, so that the microcrystalline semiconductor film is formed over a region which is positioned more on the inside than the end portion of the substrate.Type: ApplicationFiled: February 8, 2012Publication date: August 16, 2012Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.Inventors: Tetsuhiro TANAKA, Ryo TOKUMARU, Takashi OHTSUKI, Ryota TAJIMA, Erika KATO
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Patent number: 8158517Abstract: An object of the present invention is to provide a method for manufacturing a display device by improving the utilization efficiency of materials and simplifying manufacturing process. Another object of the invention is to provide a technique for forming a pattern such as a wiring having a predetermined shape included in a display device with good controllability. A method for manufacturing a wiring substrate of the invention includes the steps of: forming a first region having a subject material; modifying the surface of the subject material partly to form a second region having a boundary with respect to the first region; continuously discharging a composition containing a conductive material to a part of the first region across the boundary and the second region; solidifying the composition to form a conductive layer; and removing the conductive layer formed in a part of the first region across the boundary.Type: GrantFiled: June 22, 2005Date of Patent: April 17, 2012Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Hiroko Yamamoto, Ryo Tokumaru