Patents by Inventor Masashi Tsubuku

Masashi Tsubuku 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).

  • Publication number: 20190088785
    Abstract: An object is to reduce leakage current and parasitic capacitance of a transistor used for an LSI, a CPU, or a memory. A semiconductor integrated circuit such as an LSI, a CPU, or a memory is manufactured using a thin film transistor in which a channel formation region is formed using an oxide semiconductor which becomes an intrinsic or substantially intrinsic semiconductor by removing impurities which serve as electron donors (donors) from the oxide semiconductor and has larger energy gap than that of a silicon semiconductor. With use of a thin film transistor using a highly purified oxide semiconductor layer with sufficiently reduced hydrogen concentration, a semiconductor device with low power consumption due to leakage current can be realized.
    Type: Application
    Filed: September 5, 2018
    Publication date: March 21, 2019
    Inventors: Shunpei YAMAZAKI, Jun KOYAMA, Hiroyuki MIYAKE, Kei TAKAHASHI, Kouhei TOYOTAKA, Masashi TSUBUKU, Kosei NODA, Hideaki KUWABARA
  • Publication number: 20190088793
    Abstract: A display device including a pixel having a memory. The pixel includes at least a display element, a capacitor, an inverter, and a switch. The switch is controlled with a signal held in the capacitor and a signal output from the inverter so that voltage is supplied to the display element. The inverter and the switch can be constituted by transistors with the same polarity. A semiconductor layer included in the pixel may be formed using a light-transmitting material. Moreover, a gate electrode, a drain electrode, and a capacitor electrode may be formed using a light-transmitting conductive layer. The pixel is formed using a light-transmitting material in such a manner, whereby the display device can be a transmissive display device while including a pixel having a memory.
    Type: Application
    Filed: November 15, 2018
    Publication date: March 21, 2019
    Inventors: Hajime KIMURA, Kengo AKIMOTO, Masashi TSUBUKU, Toshinari SASAKI
  • Patent number: 10211344
    Abstract: A logic circuit includes a thin film transistor having a channel formation region formed using an oxide semiconductor, and a capacitor having terminals one of which is brought into a floating state by turning off the thin film transistor. The oxide semiconductor has a hydrogen concentration of 5×1019 (atoms/cm3) or less and thus substantially serves as an insulator in a state where an electric field is not generated. Therefore, off-state current of a thin film transistor can be reduced, leading to suppressing the leakage of electric charge stored in a capacitor, through the thin film transistor. Accordingly, a malfunction of the logic circuit can be prevented. Further, the excessive amount of current which flows in the logic circuit can be reduced through the reduction of off-state current of the thin film transistor, resulting in low power consumption of the logic circuit.
    Type: Grant
    Filed: March 18, 2013
    Date of Patent: February 19, 2019
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Jun Koyama, Masashi Tsubuku, Kosei Noda
  • Publication number: 20190035819
    Abstract: An object is to obtain a semiconductor device having a high sensitivity in detecting signals and a wide dynamic range, using a thin film transistor in which an oxide semiconductor layer is used. An analog circuit is formed with the use of a thin film transistor including an oxide semiconductor which has a function as a channel formation layer, has a hydrogen concentration of 5×1019 atoms/cm3 or lower, and substantially functions as an insulator in the state where no electric field is generated. Thus, a semiconductor device having a high sensitivity in detecting signals and a wide dynamic range can be obtained.
    Type: Application
    Filed: September 18, 2018
    Publication date: January 31, 2019
    Inventors: Shunpei YAMAZAKI, Jun KOYAMA, Atsushi HIROSE, Masashi TSUBUKU, Kosei NODA
  • Publication number: 20190024227
    Abstract: A metal oxide film containing a crystal part is provided. Alternatively, a metal oxide film with highly stable physical properties is provided. Alternatively, a metal oxide film with improved electrical characteristics is provided. Alternatively, a metal oxide film with which field-effect mobility can be increased is provided. A metal oxide film including In, M (M is Al, Ga, Y, or Sn), and Zn includes a first crystal part and a second crystal part; the first crystal part has c-axis alignment; the second crystal part has no c-axis alignment; and the existing proportion of the second crystal part is higher than the existing proportion of the first crystal part.
    Type: Application
    Filed: May 19, 2016
    Publication date: January 24, 2019
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Shunpei YAMAZAKI, Junichi KOEZUKA, Kenichi OKAZAKI, Masashi TSUBUKU
  • Publication number: 20180364510
    Abstract: A liquid crystal display device includes: a driver circuit portion; a pixel portion; a signal generation circuit for generating a control signal for driving the driver circuit portion and an image signal which is supplied to the pixel portion; a memory circuit; a comparison circuit for detecting a difference of image signals for a series of frame periods among image signals stored for respective frame periods in the memory circuit; a selection circuit which selects and outputs the image signals for the series of frame periods when the difference is detected in the comparison circuit; and a display control circuit which supplies the control signal and the image signals output from the selection circuit, to the driver circuit portion when the difference is detected in the comparison circuit, and stops supplying the control signal to the driver circuit portion when the difference is not detected in the comparison circuit.
    Type: Application
    Filed: August 23, 2018
    Publication date: December 20, 2018
    Inventors: Shunpei YAMAZAKI, Jun KOYAMA, Hiroyuki MIYAKE, Masashi TSUBUKU, Kosei NODA
  • Publication number: 20180342538
    Abstract: It is an object to manufacture a highly reliable display device using a thin film transistor having favorable electric characteristics and high reliability as a switching element. In a bottom gate thin film transistor including an amorphous oxide semiconductor, an oxide conductive layer having a crystal region is formed between an oxide semiconductor layer which has been dehydrated or dehydrogenated by heat treatment and each of a source electrode layer and a drain electrode layer which are formed using a metal material. Accordingly, contact resistance between the oxide semiconductor layer and each of the source electrode layer and the drain electrode layer can be reduced; thus, a thin film transistor having favorable electric characteristics and a highly reliable display device using the thin film transistor can be provided.
    Type: Application
    Filed: April 19, 2018
    Publication date: November 29, 2018
    Inventors: Shunpei YAMAZAKI, Toshinari SASAKI, Junichiro SAKATA, Masashi TSUBUKU
  • Publication number: 20180337289
    Abstract: A semiconductor device with improved electrical characteristics is provided. A semiconductor device with improved field effect mobility is provided. A semiconductor device in which the field-effect mobility is not lowered even at high temperatures is provided. A semiconductor device which can be formed at low temperatures is provided. A semiconductor device with improved productivity can be provided. In the semiconductor device, there is a range of a gate voltage where the field-effect mobility increases as the temperature increases within a range of the gate voltage from 0 V to 10 V. For example, such a range of a gate voltage exists at temperatures ranging from a room temperature (25° C.) to 120° C. In the semiconductor device, the off-state current is kept extremely low (lower than or equal to the detection limit of a measurement device) within the above temperature range.
    Type: Application
    Filed: July 13, 2018
    Publication date: November 22, 2018
    Inventors: Shunpei YAMAZAKI, Kenichi OKAZAKI, Masashi TSUBUKU, Satoru SAITO, Noritaka ISHIHARA
  • Patent number: 10134879
    Abstract: The on-state characteristics of a transistor are improved and thus, a semiconductor device capable of high-speed response and high-speed operation is provided. A highly reliable semiconductor device showing stable electric characteristics is made. The semiconductor device includes a transistor including a first oxide layer; an oxide semiconductor layer over the first oxide layer; a source electrode layer and a drain electrode layer in contact with the oxide semiconductor layer; a second oxide layer over the oxide semiconductor layer; a gate insulating layer over the second oxide layer; and a gate electrode layer over the gate insulating layer. An end portion of the second oxide layer and an end portion of the gate insulating layer overlap with the source electrode layer and the drain electrode layer.
    Type: Grant
    Filed: March 17, 2017
    Date of Patent: November 20, 2018
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Hideomi Suzawa, Shinya Sasagawa, Motomu Kurata, Masashi Tsubuku
  • Patent number: 10134912
    Abstract: A display device including a pixel having a memory. The pixel includes at least a display element, a capacitor, an inverter, and a switch. The switch is controlled with a signal held in the capacitor and a signal output from the inverter so that voltage is supplied to the display element. The inverter and the switch can be constituted by transistors with the same polarity. A semiconductor layer included in the pixel may be formed using a light-transmitting material. Moreover, a gate electrode, a drain electrode, and a capacitor electrode may be formed using a light-transmitting conductive layer. The pixel is formed using a light-transmitting material in such a manner, whereby the display device can be a transmissive display device while including a pixel having a memory.
    Type: Grant
    Filed: February 8, 2016
    Date of Patent: November 20, 2018
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hajime Kimura, Kengo Akimoto, Masashi Tsubuku, Toshinari Sasaki
  • Publication number: 20180323220
    Abstract: 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: Application
    Filed: July 2, 2018
    Publication date: November 8, 2018
    Inventors: Masahiro TAKAHASHI, Takuya HIROHASHI, Masashi TSUBUKU, Noritaka ISHIHARA, Masashi OOTA
  • Patent number: 10115742
    Abstract: In a transistor including an oxide semiconductor, a variation in electrical characteristics is suppressed and reliability is improved. A semiconductor device includes a transistor. The transistor includes a first gate electrode, a first insulating film over the first gate electrode, an oxide semiconductor film over the first insulating film, a second insulating film over the oxide semiconductor film, a second gate electrode over the second insulating film, and a third insulating film over the oxide semiconductor film and the second gate electrode. The oxide semiconductor film includes a channel region overlapping with the second gate electrode, a source region in contact with the third insulating film, and a drain region in contact with the third insulating film. The first gate electrode and the second gate electrode are electrically connected to each other.
    Type: Grant
    Filed: February 8, 2017
    Date of Patent: October 30, 2018
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Kenichi Okazaki, Masashi Tsubuku, Haruyuki Baba, Sachie Shigenobu, Emi Koezuka
  • Patent number: 10115743
    Abstract: An object is to obtain a semiconductor device having a high sensitivity in detecting signals and a wide dynamic range, using a thin film transistor in which an oxide semiconductor layer is used. An analog circuit is formed with the use of a thin film transistor including an oxide semiconductor which has a function as a channel formation layer, has a hydrogen concentration of 5×1019 atoms/cm3 or lower, and substantially functions as an insulator in the state where no electric field is generated. Thus, a semiconductor device having a high sensitivity in detecting signals and a wide dynamic range can be obtained.
    Type: Grant
    Filed: July 18, 2017
    Date of Patent: October 30, 2018
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Jun Koyama, Atsushi Hirose, Masashi Tsubuku, Kosei Noda
  • Publication number: 20180308989
    Abstract: An oxide semiconductor film which has more stable electric conductivity is provided. The oxide semiconductor film comprises a crystalline region. The oxide semiconductor film has a first peak of electron diffraction intensity with a full width at half maximum of greater than or equal to 0.4 nm?1 and less than or equal to 0.7 nm?1 in a region where a magnitude of a scattering vector is greater than or equal to 3.3 nm?1 and less than or equal to 4.1 nm?1. The oxide semiconductor film has a second peak of electron diffraction intensity with a full width at half maximum of greater than or equal to 0.45 nm?1 and less than or equal to 1.4 nm?1 in a region where a magnitude of a scattering vector is greater than or equal to 5.5 nm?1 and less than or equal to 7.1 nm?1.
    Type: Application
    Filed: June 28, 2018
    Publication date: October 25, 2018
    Inventors: Shunpei YAMAZAKI, Masashi TSUBUKU, Kengo AKIMOTO, Hiroki OHARA, Tatsuya HONDA, Takatsugu OMATA, Yusuke NONAKA, Masahiro TAKAHASHI, Akiharu MIYANAGA
  • Publication number: 20180301476
    Abstract: To reduce a leakage current of a transistor so that malfunction of a logic circuit can be suppressed. The logic circuit includes a transistor which includes an oxide semiconductor layer having a function of a channel formation layer and in which an off current is 1×10?13A or less per micrometer in channel width. A first signal, a second signal, and a third signal that is a clock signal are input as input signals. A fourth signal and a fifth signal whose voltage states are set in accordance with the first to third signals which have been input are output as output signals.
    Type: Application
    Filed: June 14, 2018
    Publication date: October 18, 2018
    Inventors: Shunpei YAMAZAKI, Jun KOYAMA, Masashi TSUBUKU, Kosei NODA
  • Patent number: 10103275
    Abstract: An object is to reduce leakage current and parasitic capacitance of a transistor used for an LSI, a CPU, or a memory. A semiconductor integrated circuit included in an LSI, a CPU, or a memory is manufactured using the transistor which is formed using an oxide semiconductor which is an intrinsic or substantially intrinsic semiconductor obtained by removal of impurities which serve as electron donors (donors) from the oxide semiconductor and has larger energy gap than a silicon semiconductor, and is formed over a semiconductor substrate. With the transistor which is formed over the semiconductor substrate and includes the highly purified oxide semiconductor layer with sufficiently reduced hydrogen concentration, a semiconductor device whose power consumption due to leakage current is low can be realized.
    Type: Grant
    Filed: May 31, 2017
    Date of Patent: October 16, 2018
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Jun Koyama, Hiroyuki Miyake, Kei Takahashi, Kouhei Toyotaka, Masashi Tsubuku, Kosei Noda, Hideaki Kuwabara
  • Patent number: 10103277
    Abstract: A method comprising a step of forming an oxide semiconductor film over a substrate by a sputtering method while heating the substrate at a temperature of higher than 200° C. and lower than or equal to 400° C. is provided. The oxide semiconductor film comprises a crystalline region and is in a non-single-crystal state. The step of forming the oxide semiconductor film is performed by using a sputtering target comprising indium, gallium, zinc and oxygen and a sputtering gas comprising at least one of a rare gas and oxygen.
    Type: Grant
    Filed: July 13, 2017
    Date of Patent: October 16, 2018
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Masashi Tsubuku, Kengo Akimoto, Hiroki Ohara, Tatsuya Honda, Takatsugu Omata, Yusuke Nonaka, Masahiro Takahashi, Akiharu Miyanaga
  • Patent number: 10074747
    Abstract: An object is to reduce leakage current and parasitic capacitance of a transistor used for an LSI, a CPU, or a memory. A semiconductor integrated circuit such as an LSI, a CPU, or a memory is manufactured using a thin film transistor in which a channel formation region is formed using an oxide semiconductor which becomes an intrinsic or substantially intrinsic semiconductor by removing impurities which serve as electron donors (donors) from the oxide semiconductor and has larger energy gap than that of a silicon semiconductor. With use of a thin film transistor using a highly purified oxide semiconductor layer with sufficiently reduced hydrogen concentration, a semiconductor device with low power consumption due to leakage current can be realized.
    Type: Grant
    Filed: December 8, 2016
    Date of Patent: September 11, 2018
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Jun Koyama, Hiroyuki Miyake, Kei Takahashi, Kouhei Toyotaka, Masashi Tsubuku, Kosei Noda, Hideaki Kuwabara
  • Patent number: 10061172
    Abstract: A liquid crystal display device includes: a driver circuit portion; a pixel portion; a signal generation circuit for generating a control signal for driving the driver circuit portion and an image signal which is supplied to the pixel portion; a memory circuit; a comparison circuit for detecting a difference of image signals for a series of frame periods among image signals stored for respective frame periods in the memory circuit; a selection circuit which selects and outputs the image signals for the series of frame periods when the difference is detected in the comparison circuit; and a display control circuit which supplies the control signal and the image signals output from the selection circuit, to the driver circuit portion when the difference is detected in the comparison circuit, and stops supplying the control signal to the driver circuit portion when the difference is not detected in the comparison circuit.
    Type: Grant
    Filed: October 14, 2010
    Date of Patent: August 28, 2018
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Jun Koyama, Hiroyuki Miyake, Masashi Tsubuku, Kosei Noda
  • Patent number: 10050132
    Abstract: 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: Grant
    Filed: July 31, 2017
    Date of Patent: August 14, 2018
    Assignee: 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