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: 20190312063Abstract: 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: ApplicationFiled: June 10, 2019Publication date: October 10, 2019Inventors: Shunpei YAMAZAKI, Jun KOYAMA, Atsushi HIROSE, Masashi TSUBUKU, Kosei NODA
-
Publication number: 20190312062Abstract: One embodiment of the invention is characterized as follows. A display device comprising: a display area including a plurality of pixels, each of the pixels has a first TFT and a second TFT, the first TFT and the second TFT comprise an oxide semiconductor, the first TFT and the second TFT are covered by an interlayer insulating film, a first through hole is formed in the in the interlayer insulating film to connect a drain of the first TFT, wherein a distance d1 between a center of the first through hole and an edge of a channel of the first TFT is shorter than a distance d2 between a center of the first through hole and an edge of a channel of the second TFT, a channel length of the first TFT is shorter than a channel length of the second TFT.Type: ApplicationFiled: March 28, 2019Publication date: October 10, 2019Applicant: Japan Display Inc.Inventors: Miyuki ISHIKAWA, Masashi TSUBUKU
-
Patent number: 10439074Abstract: 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: GrantFiled: July 13, 2018Date of Patent: October 8, 2019Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Kenichi Okazaki, Masashi Tsubuku, Satoru Saito, Noritaka Ishihara
-
Patent number: 10418384Abstract: 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: GrantFiled: April 19, 2018Date of Patent: September 17, 2019Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Toshinari Sasaki, Junichiro Sakata, Masashi Tsubuku
-
Patent number: 10374030Abstract: A highly reliable semiconductor device including an oxide semiconductor is provided. Provided is a semiconductor device including an oxide semiconductor layer, an insulating layer in contact with the oxide semiconductor layer, a gate electrode layer overlapping with the oxide semiconductor layer, and a source electrode layer and a drain electrode layer electrically connected to the oxide semiconductor layer. The oxide semiconductor layer includes a first region having a crystal whose size is less than or equal to 10 nm and a second region which overlaps with the insulating layer with the first region provided therebetween and which includes a crystal part whose c-axis is aligned in a direction parallel to a normal vector of the surface of the oxide semiconductor layer.Type: GrantFiled: August 25, 2017Date of Patent: August 6, 2019Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Masahiro Takahashi, Takuya Hirohashi, Masashi Tsubuku, Masashi Oota
-
Patent number: 10373843Abstract: An object is to provide a display device with excellent display characteristics, where a pixel circuit and a driver circuit provided over one substrate are formed using transistors which have different structures corresponding to characteristics of the respective circuits. The driver circuit portion includes a driver circuit transistor in which a gate electrode layer, a source electrode layer, and a drain electrode layer are formed using a metal film, and a channel layer is formed using an oxide semiconductor. The pixel portion includes a pixel transistor in which a gate electrode layer, a source electrode layer, and a drain electrode layer are formed using an oxide conductor, and a semiconductor layer is formed using an oxide semiconductor. The pixel transistor is formed using a light-transmitting material, and thus, a display device with higher aperture ratio can be manufactured.Type: GrantFiled: July 2, 2015Date of Patent: August 6, 2019Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Junichiro Sakata, Masashi Tsubuku, Kengo Akimoto, Miyuki Hosoba, Masayuki Sakakura, Yoshiaki Oikawa
-
Publication number: 20190237585Abstract: A semiconductor device includes a gate electrode, a gate insulating film which includes oxidized material containing silicon and covers the gate electrode, an oxide semiconductor film provided to be in contact with the gate insulating film and overlap with at least the gate electrode, and a source electrode and a drain electrode electrically connected to the oxide semiconductor film. In the oxide semiconductor film, a first region which is provided to be in contact with the gate insulating film and have a thickness less than or equal to 5 nm has a silicon concentration lower than or equal to 1.0 at. %, and a region in the oxide semiconductor film other than the first region has lower silicon concentration than the first region. At least the first region includes a crystal portion.Type: ApplicationFiled: April 11, 2019Publication date: August 1, 2019Inventors: Tatsuya HONDA, Masashi TSUBUKU, Yusuke NONAKA, Takashi SHIMAZU, Shunpei YAMAZAKI
-
Patent number: 10319744Abstract: 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: GrantFiled: September 18, 2018Date of Patent: June 11, 2019Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Jun Koyama, Atsushi Hirose, Masashi Tsubuku, Kosei Noda
-
Patent number: 10310348Abstract: 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: GrantFiled: August 23, 2018Date of Patent: June 4, 2019Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Jun Koyama, Hiroyuki Miyake, Masashi Tsubuku, Kosei Noda
-
Patent number: 10290744Abstract: A semiconductor device includes a gate electrode, a gate insulating film which includes oxidized material containing silicon and covers the gate electrode, an oxide semiconductor film provided to be in contact with the gate insulating film and overlap with at least the gate electrode, and a source electrode and a drain electrode electrically connected to the oxide semiconductor film. In the oxide semiconductor film, a first region which is provided to be in contact with the gate insulating film and have a thickness less than or equal to 5 nm has a silicon concentration lower than or equal to 1.0 at. %, and a region in the oxide semiconductor film other than the first region has lower silicon concentration than the first region. At least the first region includes a crystal portion.Type: GrantFiled: February 2, 2017Date of Patent: May 14, 2019Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Tatsuya Honda, Masashi Tsubuku, Yusuke Nonaka, Takashi Shimazu, Shunpei Yamazaki
-
Publication number: 20190103478Abstract: 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: ApplicationFiled: November 19, 2018Publication date: April 4, 2019Inventors: Shunpei YAMAZAKI, Hideomi SUZAWA, Shinya SASAGAWA, Motomu KURATA, Masashi TSUBUKU
-
Publication number: 20190088793Abstract: 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: ApplicationFiled: November 15, 2018Publication date: March 21, 2019Inventors: Hajime KIMURA, Kengo AKIMOTO, Masashi TSUBUKU, Toshinari SASAKI
-
Publication number: 20190088785Abstract: 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: ApplicationFiled: September 5, 2018Publication date: March 21, 2019Inventors: Shunpei YAMAZAKI, Jun KOYAMA, Hiroyuki MIYAKE, Kei TAKAHASHI, Kouhei TOYOTAKA, Masashi TSUBUKU, Kosei NODA, Hideaki KUWABARA
-
Patent number: 10211344Abstract: 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: GrantFiled: March 18, 2013Date of Patent: February 19, 2019Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Jun Koyama, Masashi Tsubuku, Kosei Noda
-
Publication number: 20190035819Abstract: 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: ApplicationFiled: September 18, 2018Publication date: January 31, 2019Inventors: Shunpei YAMAZAKI, Jun KOYAMA, Atsushi HIROSE, Masashi TSUBUKU, Kosei NODA
-
Publication number: 20190024227Abstract: 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: ApplicationFiled: May 19, 2016Publication date: January 24, 2019Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.Inventors: Shunpei YAMAZAKI, Junichi KOEZUKA, Kenichi OKAZAKI, Masashi TSUBUKU
-
Publication number: 20180364510Abstract: 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: ApplicationFiled: August 23, 2018Publication date: December 20, 2018Inventors: Shunpei YAMAZAKI, Jun KOYAMA, Hiroyuki MIYAKE, Masashi TSUBUKU, Kosei NODA
-
Publication number: 20180342538Abstract: 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: ApplicationFiled: April 19, 2018Publication date: November 29, 2018Inventors: Shunpei YAMAZAKI, Toshinari SASAKI, Junichiro SAKATA, Masashi TSUBUKU
-
Publication number: 20180337289Abstract: 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: ApplicationFiled: July 13, 2018Publication date: November 22, 2018Inventors: Shunpei YAMAZAKI, Kenichi OKAZAKI, Masashi TSUBUKU, Satoru SAITO, Noritaka ISHIHARA
-
Patent number: 10134912Abstract: 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: GrantFiled: February 8, 2016Date of Patent: November 20, 2018Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Hajime Kimura, Kengo Akimoto, Masashi Tsubuku, Toshinari Sasaki