Patents by Inventor Atsuo Isobe

Atsuo Isobe 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).

  • Patent number: 9530852
    Abstract: It is an object to provide a semiconductor device in which a short-channel effect is suppressed and miniaturization is achieved, and a manufacturing method thereof. A trench is formed in an insulating layer and impurities are added to an oxide semiconductor film in contact with an upper end corner portion of the trench, whereby a source region and a drain region are formed. With the above structure, miniaturization can be achieved. Further, with the trench, a short-channel effect can be suppressed setting the depth of the trench as appropriate even when a distance between a source electrode layer and a drain electrode layer is shortened.
    Type: Grant
    Filed: July 16, 2015
    Date of Patent: December 27, 2016
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Atsuo Isobe, Toshinari Sasaki, Junichi Koezuka, Shunpei Yamazaki
  • Patent number: 9496375
    Abstract: To improve productivity of a transistor that includes an oxide semiconductor and has good electrical characteristics. In a top-gate transistor including a gate insulating film and a gate electrode over an oxide semiconductor film, a metal film is formed over the oxide semiconductor film, oxygen is added to the metal film to form a metal oxide film, and the metal oxide film is used as a gate insulating film. After an oxide insulating film is formed over the oxide semiconductor film, a metal film may be formed over the oxide insulating film. Oxygen is added to the metal film to form a metal oxide film and added also to the oxide semiconductor film or the oxide insulating film.
    Type: Grant
    Filed: August 21, 2015
    Date of Patent: November 15, 2016
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Atsuo Isobe, Kunio Hosoya
  • Patent number: 9472656
    Abstract: A semiconductor device including a minute transistor with a short channel length is provided. A gate insulating layer is formed over a gate electrode layer; an oxide semiconductor layer is formed over the gate insulating layer; a first conductive layer and a second conductive layer are formed over the oxide semiconductor layer; a conductive film is formed over the first conductive layer and the second conductive layer; a resist mask is formed over the conductive film by performing electron beam exposure; and then a third conductive layer and a fourth conductive layer are formed over and in contact with the first conductive layer and the second conductive layer, respectively, by selectively etching the conductive film.
    Type: Grant
    Filed: August 27, 2015
    Date of Patent: October 18, 2016
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Atsuo Isobe, Yoshinori Ieda, Masaharu Nagai
  • Patent number: 9466622
    Abstract: To provide a liquid crystal display device having high quality display by obtaining a high aperture ratio while securing a sufficient storage capacitor (Cs), and at the same time, by dispersing a load (a pixel writing-in electric current) of a capacitor wiring in a timely manner to effectively reduce the load. A scanning line is formed on a different layer from a gate electrode and the capacitor wiring is arranged so as to be parallel with a signal line. Each pixel is connected to the individually independent capacitor wiring via a dielectric. Therefore, variations in the electric potential of the capacitor wiring caused by a writing-in electric current of a neighboring pixel can be avoided, whereby obtaining satisfactory display images.
    Type: Grant
    Filed: January 14, 2016
    Date of Patent: October 11, 2016
    Assignee: Semiconductor Energy Laboratory Co., LTD.
    Inventors: Hiroshi Shibata, Atsuo Isobe
  • Patent number: 9431545
    Abstract: A miniaturized transistor having high electric characteristics is provided with high yield. In a semiconductor device including the transistor, high performance, high reliability, and high productivity are achieved. In a semiconductor device including a transistor in which an oxide semiconductor film, a gate insulating film, and a gate electrode layer on side surfaces of which sidewall insulating layers are provided are stacked in this order, source and drain electrode layers are provided in contact with the oxide semiconductor film and the sidewall insulating layers. In a process for manufacturing the semiconductor device, a conductive film and an interlayer insulating film are stacked to cover the oxide semiconductor film, the sidewall insulating layers, and the gate electrode layer, and the interlayer insulating film and the conductive film over the gate electrode layer are removed by a chemical mechanical polishing method, so that the source and drain electrode layers are formed.
    Type: Grant
    Filed: September 6, 2012
    Date of Patent: August 30, 2016
    Assignee: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Toshihiko Saito, Atsuo Isobe, Kazuya Hanaoka, Junichi Koezuka, Shinya Sasagawa, Motomu Kurata, Akihiro Ishizuka
  • Publication number: 20160233865
    Abstract: To provide a semiconductor device including element layers that are stacked. A first wiring layer and a second wiring layer are stacked between a first element layer and a second element layer. A third wiring layer and a fourth wiring layer are stacked over the second element layer. Transistors of logic cells are provided in the first element layer. Wirings of the logic cells are provided in the first wiring layer or the second wiring layer. Input ports and output ports of the logic cells are provided in the third wiring layer. The input port of one of the logic cells is connected to the output port of another logic cell through the wiring of the third wiring layer or the fourth wiring layer. Connecting the logic cells through the wiring layers over the second element layer improves the efficiency of steps of arranging and connecting the logic cells.
    Type: Application
    Filed: February 3, 2016
    Publication date: August 11, 2016
    Inventors: Hikaru TAMURA, Naoaki TSUTSUI, Atsuo ISOBE
  • Publication number: 20160203852
    Abstract: A memory device includes a first memory circuit including a silicon transistor, a selection circuit including a silicon transistor, and a second memory circuit including oxide semiconductor transistors and a storage capacitor, in which one terminal of the storage capacitor is connected to a portion where two oxide semiconductor transistors are connected in series, an output of the second memory circuit is connected to a second input terminal of the selection circuit, and an input of the second memory circuit is connected to a first input terminal of the selection circuit or an output terminal of the first memory circuit.
    Type: Application
    Filed: March 17, 2016
    Publication date: July 14, 2016
    Inventors: Naoaki TSUTSUI, Atsuo ISOBE, Wataru UESUGI, Takuro OHMARU
  • Publication number: 20160204268
    Abstract: A semiconductor device which is miniaturized while favorable characteristics thereof are maintained is provided. In addition, the miniaturized semiconductor device is provided with a high yield. The semiconductor device has a structure including an oxide semiconductor film provided over a substrate having an insulating surface; a source electrode layer and a drain electrode layer which are provided in contact with side surfaces of the oxide semiconductor film and have a thickness larger than that of the oxide semiconductor film; a gate insulating film provided over the oxide semiconductor film, the source electrode layer, and the drain electrode layer; and a gate electrode layer provided in a depressed portion formed by a step between a top surface of the oxide semiconductor film and top surfaces of the source electrode layer and the drain electrode layer.
    Type: Application
    Filed: February 22, 2016
    Publication date: July 14, 2016
    Inventors: Takehisa HATANO, Sachiaki TEZUKA, Atsuo ISOBE
  • Patent number: 9385713
    Abstract: A retention circuit provided in a logic circuit enables power gating. The retention circuit includes a first terminal, a node, a capacitor, and first to third transistors. The first transistor controls electrical connection between the first terminal and an input terminal of the logic circuit. The second transistor controls electrical connection between an output terminal of the logic circuit and the node. The third transistor controls electrical connection between the node and the input terminal of the logic circuit. A gate of the first transistor is electrically connected to a gate of the second transistor. In a data retention period, the node becomes electrically floating. The voltage of the node is held by the capacitor.
    Type: Grant
    Filed: October 5, 2015
    Date of Patent: July 5, 2016
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Wataru Uesugi, Hikaru Tamura, Atsuo Isobe
  • Patent number: 9373723
    Abstract: The present invention provides a semiconductor device which suppresses a short circuit and a leakage current between a semiconductor film and a gate electrode generated by a break or thin thickness of a gate insulating film in an end portion of a channel region of the semiconductor film, and the manufacturing method of the semiconductor device. Plural thin film transistors which each have semiconductor film provided over a substrate continuously, conductive films provided over the semiconductor film through a gate insulating film, source and drain regions provided in the semiconductor film which are not overlapped with the conductive films, and channel regions provided in the semiconductor film existing under the conductive films and between the source and drain regions. And impurity regions provided in the semiconductor film which is not overlapped with the conductive film and provided adjacent to the source and drain regions.
    Type: Grant
    Filed: July 21, 2014
    Date of Patent: June 21, 2016
    Assignee: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Tamae Takano, Atsuo Isobe
  • Publication number: 20160133656
    Abstract: To provide a liquid crystal display device having high quality display by obtaining a high aperture ratio while securing a sufficient storage capacitor (Cs), and at the same time, by dispersing a load (a pixel writing-in electric current) of a capacitor wiring in a timely manner to effectively reduce the load. A scanning line is formed on a different layer from a gate electrode and the capacitor wiring is arranged so as to be parallel with a signal line. Each pixel is connected to the individually independent capacitor wiring via a dielectric. Therefore, variations in the electric potential of the capacitor wiring caused by a writing-in electric current of a neighboring pixel can be avoided, whereby obtaining satisfactory display images.
    Type: Application
    Filed: January 14, 2016
    Publication date: May 12, 2016
    Inventors: Hiroshi SHIBATA, Atsuo ISOBE
  • Publication number: 20160111451
    Abstract: A semiconductor device production system using a laser crystallization method is provided which can avoid forming grain boundaries in a channel formation region of a TFT, thereby preventing grain boundaries from lowering the mobility of the TFT greatly, from lowering ON current, and from increasing OFF current. Rectangular or stripe pattern depression and projection portions are formed on an insulating film. A semiconductor film is formed on the insulating film. The semiconductor film is irradiated with continuous wave laser light by running the laser light along the stripe pattern depression and projection portions of the insulating film or along the major or minor axis direction of the rectangle. Although continuous wave laser light is most preferred among laser light, it is also possible to use pulse oscillation laser light in irradiating the semiconductor film.
    Type: Application
    Filed: October 27, 2015
    Publication date: April 21, 2016
    Inventors: Atsuo ISOBE, Shunpei YAMAZAKI, Koji DAIRIKI, Hiroshi SHIBATA, Chiho KOKUBO, Tatsuya ARAO, Masahiko HAYAKAWA, Hidekazu MIYAIRI, Akihisa SHIMOMURA, Koichiro TANAKA, Mai AKIBA
  • Publication number: 20160105174
    Abstract: A retention circuit provided in a logic circuit enables power gating. The retention circuit includes a first terminal, a node, a capacitor, and first to third transistors. The first transistor controls electrical connection between the first terminal and an input terminal of the logic circuit. The second transistor controls electrical connection between an output terminal of the logic circuit and the node. The third transistor controls electrical connection between the node and the input terminal of the logic circuit. A gate of the first transistor is electrically connected to a gate of the second transistor. In a data retention period, the node becomes electrically floating. The voltage of the node is held by the capacitor.
    Type: Application
    Filed: October 5, 2015
    Publication date: April 14, 2016
    Inventors: Wataru UESUGI, Hikaru TAMURA, Atsuo ISOBE
  • Publication number: 20160093642
    Abstract: A first conductive film overlapping with an oxide semiconductor film is formed over a gate insulating film, a gate electrode is formed by selectively etching the first conductive film using a resist subjected to electron beam exposure, a first insulating film is formed over the gate insulating film and the gate electrode, removing a part of the first insulating film while the gate electrode is not exposed, an anti-reflective film is formed over the first insulating film, the anti-reflective film, the first insulating film and the gate insulating film are selectively etched using a resist subjected to electron beam exposure, and a source electrode in contact with one end of the oxide semiconductor film and one end of the first insulating film and a drain electrode in contact with the other end of the oxide semiconductor film and the other end of the first insulating film are formed.
    Type: Application
    Filed: December 7, 2015
    Publication date: March 31, 2016
    Inventors: Atsuo ISOBE, Yutaka OKAZAKI, Kazuya HANAOKA, Shinya SASAGAWA, Motomu KURATA
  • Patent number: 9293186
    Abstract: A memory device includes a first memory circuit including a silicon transistor, a selection circuit including a silicon transistor, and a second memory circuit including oxide semiconductor transistors and a storage capacitor, in which one terminal of the storage capacitor is connected to a portion where two oxide semiconductor transistors are connected in series, an output of the second memory circuit is connected to a second input terminal of the selection circuit, and an input of the second memory circuit is connected to a first input terminal of the selection circuit or an output terminal of the first memory circuit.
    Type: Grant
    Filed: March 13, 2014
    Date of Patent: March 22, 2016
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Naoaki Tsutsui, Atsuo Isobe, Wataru Uesugi, Takuro Ohmaru
  • Patent number: 9269798
    Abstract: A semiconductor device which is miniaturized while favorable characteristics thereof are maintained is provided. In addition, the miniaturized semiconductor device is provided with a high yield. The semiconductor device has a structure including an oxide semiconductor film provided over a substrate having an insulating surface; a source electrode layer and a drain electrode layer which are provided in contact with side surfaces of the oxide semiconductor film and have a thickness larger than that of the oxide semiconductor film; a gate insulating film provided over the oxide semiconductor film, the source electrode layer, and the drain electrode layer; and a gate electrode layer provided in a depressed portion formed by a step between a top surface of the oxide semiconductor film and top surfaces of the source electrode layer and the drain electrode layer.
    Type: Grant
    Filed: June 11, 2015
    Date of Patent: February 23, 2016
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Takehisa Hatano, Sachiaki Tezuka, Atsuo Isobe
  • Patent number: 9250490
    Abstract: To provide a liquid crystal display device having high quality display by obtaining a high aperture ratio while securing a sufficient storage capacitor (Cs), and at the same time, by dispersing a load (a pixel writing-in electric current) of a capacitor wiring in a timely manner to effectively reduce the load. A scanning line is formed on a different layer from a gate electrode and the capacitor wiring is arranged so as to be parallel with a signal line. Each pixel is connected to the individually independent capacitor wiring via a dielectric. Therefore, variations in the electric potential of the capacitor wiring caused by a writing-in electric current of a neighboring pixel can be avoided, whereby obtaining satisfactory display images.
    Type: Grant
    Filed: October 29, 2014
    Date of Patent: February 2, 2016
    Assignee: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Hiroshi Shibata, Atsuo Isobe
  • Patent number: 9252286
    Abstract: A first conductive film overlapping with an oxide semiconductor film is formed over a gate insulating film, a gate electrode is formed by selectively etching the first conductive film using a resist subjected to electron beam exposure, a first insulating film is formed over the gate insulating film and the gate electrode, removing a part of the first insulating film while the gate electrode is not exposed, an anti-reflective film is formed over the first insulating film, the anti-reflective film, the first insulating film and the gate insulating film are selectively etched using a resist subjected to electron beam exposure, and a source electrode in contact with one end of the oxide semiconductor film and one end of the first insulating film and a drain electrode in contact with the other end of the oxide semiconductor film and the other end of the first insulating film are formed.
    Type: Grant
    Filed: May 22, 2014
    Date of Patent: February 2, 2016
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Atsuo Isobe, Yutaka Okazaki, Kazuya Hanaoka, Shinya Sasagawa, Motomu Kurata
  • Patent number: 9236428
    Abstract: A structure including an oxide semiconductor layer which is provided over an insulating surface and includes a channel formation region and a pair of low-resistance regions between which the channel formation region is positioned, a gate insulating film covering a top surface and a side surface of the oxide semiconductor layer, a gate electrode covering a top surface and a side surface of the channel formation region with the gate insulating film positioned therebetween, and electrodes electrically connected to the low-resistance regions is employed. The electrodes are electrically connected to at least side surfaces of the low-resistance regions, so that contact resistance with the source electrode and the drain electrode is reduced.
    Type: Grant
    Filed: October 8, 2014
    Date of Patent: January 12, 2016
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Atsuo Isobe, Hiromichi Godo
  • Publication number: 20150380529
    Abstract: To improve productivity of a transistor that includes an oxide semiconductor and has good electrical characteristics. In a top-gate transistor including a gate insulating film and a gate electrode over an oxide semiconductor film, a metal film is formed over the oxide semiconductor film, oxygen is added to the metal film to form a metal oxide film, and the metal oxide film is used as a gate insulating film. After an oxide insulating film is formed over the oxide semiconductor film, a metal film may be formed over the oxide insulating film. Oxygen is added to the metal film to form a metal oxide film and added also to the oxide semiconductor film or the oxide insulating film.
    Type: Application
    Filed: August 21, 2015
    Publication date: December 31, 2015
    Inventors: Atsuo ISOBE, Kunio HOSOYA