Patents by Inventor Hiromichi Godo

Hiromichi Godo 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: 20150069393
    Abstract: Manufactured is a transistor including an oxide semiconductor layer, a source electrode layer and a drain electrode layer overlapping with part of the oxide semiconductor layer, a gate insulating layer overlapping with the oxide semiconductor layer, the source electrode layer, and the drain electrode layer, and a gate electrode overlapping with part of the oxide semiconductor layer with the gate insulating layer provided therebetween, wherein, after the oxide semiconductor layer which is to be a channel formation region is irradiated with light and the light irradiation is stopped, a relaxation time of carriers in photoresponse characteristics of the oxide semiconductor layer has at least two kinds of modes: ?1 and ?2, ?1<?2 is satisfied, and ?2 is 300 seconds or less. In addition, a semiconductor device including the transistor is manufactured.
    Type: Application
    Filed: November 19, 2014
    Publication date: March 12, 2015
    Inventors: Masashi TSUBUKU, Takayuki INOUE, Suzunosuke HIRAISHI, Erumu KIKUCHI, Hiromichi GODO, Shuhei YOSHITOMI, Koki INOUE, Akiharu MIYANAGA, Shunpei YAMAZAKI
  • Patent number: 8962386
    Abstract: To reduce oxygen vacancies in an oxide semiconductor film and the vicinity of the oxide semiconductor film and to improve electric characteristics of a transistor including the oxide semiconductor film. A semiconductor device includes a gate electrode whose Gibbs free energy for oxidation is higher than that of a gate insulating film. In a region where the gate electrode is in contact with the gate insulating film, oxygen moves from the gate electrode to the gate insulating film, which is caused because the gate electrode has higher Gibbs free energy for oxidation than the gate insulating film. The oxygen passes through the gate insulating film and is supplied to the oxide semiconductor film in contact with the gate insulating film, whereby oxygen vacancies in the oxide semiconductor film and the vicinity of the oxide semiconductor film can be reduced.
    Type: Grant
    Filed: November 12, 2012
    Date of Patent: February 24, 2015
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hiromichi Godo, Tetsuhiro Tanaka
  • Publication number: 20150049277
    Abstract: An object is to provide a semiconductor device provided with a thin film transistor having excellent electric characteristics using an oxide semiconductor layer. An In—Sn—O-based oxide semiconductor layer including SiOX is used for a channel formation region. In order to reduce contact resistance between the In—Sn—O-based oxide semiconductor layer including SiOX and a wiring layer formed from a metal material having low electric resistance, a source region or drain region is formed between a source electrode layer or drain electrode layer and the In—Sn—O-based oxide semiconductor layer including SiOX. The source region or drain region and a pixel region are formed using an In—Sn—O-based oxide semiconductor layer which does not include SiOX.
    Type: Application
    Filed: October 29, 2014
    Publication date: February 19, 2015
    Inventors: Yoshiaki OIKAWA, Hotaka MARUYAMA, Hiromichi GODO, Daisuke KAWAE, Shunpei YAMAZAKI
  • Patent number: 8957462
    Abstract: A semiconductor device such as a transistor with an excellent OFF characteristic even when a channel is short is provided. A periphery of a source is surrounded by an extension region and a halo region, a periphery of a drain is surrounded by an extension region and a halo region, and a substrate with low impurity concentration is not in contact with the source or the drain. Moreover, a high-work-function electrode is provided via a gate insulator, and electrons entering the vicinity of a surface of the substrate from the extension regions are eliminated. With such a structure, the impurity concentration of the channel region can be decreased even when the channel is short, and a favorable transistor characteristic can be obtained.
    Type: Grant
    Filed: December 8, 2011
    Date of Patent: February 17, 2015
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Hiromichi Godo, Yasuhiko Takemura
  • Publication number: 20150021603
    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: Application
    Filed: October 8, 2014
    Publication date: January 22, 2015
    Inventors: Atsuo ISOBE, Hiromichi GODO
  • Patent number: 8927981
    Abstract: The drain voltage of a transistor is determined depending on the driving voltage of an element connected to the transistor. With downsizing of a transistor, intensity of the electric field concentrated in the drain region is increased, and hot carriers are easily generated. An object is to provide a transistor in which the electric field hardly concentrates in the drain region. Another object is to provide a display device including such a transistor. End portions of first and second wiring layers having high electrical conductivity do not overlap with a gate electrode layer, whereby concentration of an electric field in the vicinity of a first electrode layer and a second electrode layer is reduced; thus, generation of hot carriers is suppressed. In addition, one of the first and second electrode layers having higher resistivity than the first and second wiring layers is used as a drain electrode layer.
    Type: Grant
    Filed: March 17, 2010
    Date of Patent: January 6, 2015
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Kengo Akimoto, Hiromichi Godo, Akiharu Miyanaga
  • Publication number: 20150004746
    Abstract: An object is to provide a transistor including an oxide layer which includes Zn and does not include a rare metal such as In or Ga. Another object is to reduce an off current and stabilize electric characteristics in the transistor including an oxide layer which includes Zn. A transistor including an oxide layer including Zn is formed by stacking an oxide semiconductor layer including insulating oxide over an oxide layer so that the oxide layer is in contact with a source electrode layer or a drain electrode layer with the oxide semiconductor layer including insulating oxide interposed therebetween, whereby variation in the threshold voltage of the transistor can be reduced and electric characteristics can be stabilized.
    Type: Application
    Filed: September 18, 2014
    Publication date: January 1, 2015
    Inventors: Shunpei YAMAZAKI, Hiromichi GODO, Hideyuki KISHIDA
  • Publication number: 20140374756
    Abstract: An object is to provide a semiconductor device having electrical characteristics such as high withstand voltage, low reverse saturation current, and high on-state current. In particular, an object is to provide a power diode and a rectifier which include non-linear elements. An embodiment of the present invention is a semiconductor device including a first electrode, a gate insulating layer covering the first electrode, an oxide semiconductor layer in contact with the gate insulating layer and overlapping with the first electrode, a pair of second electrodes covering end portions of the oxide semiconductor layer, an insulating layer covering the pair of second electrodes and the oxide semiconductor layer, and a third electrode in contact with the insulating layer and between the pair of second electrodes. The pair of second electrodes are in contact with end surfaces of the oxide semiconductor layer.
    Type: Application
    Filed: September 11, 2014
    Publication date: December 25, 2014
    Inventors: Shunpei YAMAZAKI, Hiromichi GODO, Satoshi KOBAYASHI
  • Patent number: 8916866
    Abstract: A semiconductor device includes a first gate electrode; a gate insulating layer covering the first gate electrode; an oxide semiconductor layer that overlaps with the first gate electrode; oxide semiconductor layers having high carrier density covering end portions of the oxide semiconductor layer; a source electrode and a drain electrode in contact with the oxide semiconductor layers having high carrier density; an insulating layer covering the source electrode, the drain electrode, and the oxide semiconductor layer; and a second gate electrode that is in contact with the insulating layer. Each of the oxide semiconductor layers is in contact with part of each of an upper surface, a lower surface, and a side surface of one of the end portions of the oxide semiconductor layer and part of an upper surface of the gate insulating layer.
    Type: Grant
    Filed: October 24, 2011
    Date of Patent: December 23, 2014
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hiromichi Godo, Satoshi Kobayashi
  • Patent number: 8912016
    Abstract: Provided is a test method by which a transistor whose reliability is low can be detected with low stress and high accuracy in a shorter period of time than a BT test. Provided is to detect a transistor whose reliability is high in a shorter period of time than a BT test and manufacture an electronic device with high reliability efficiently. Hysteresis characteristics revealed in the result of the Vg-Id measurement with light irradiation to the transistor correlate with the result of a BT test; whether the reliability of the transistor is Good or Not-Good can be judged. Accordingly, the test method by which a transistor whose reliability is low can be detected with low stress and high accuracy in a shorter period of time than a BT test can be provided.
    Type: Grant
    Filed: June 17, 2011
    Date of Patent: December 16, 2014
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hiromichi Godo, Shuhei Yoshitomi
  • Patent number: 8901806
    Abstract: A novel display device with higher reliability having a structure of blocking moisture and oxygen, which deteriorate the characteristics of the display device, from penetrating through a sealing region and a method of manufacturing thereof is provided.
    Type: Grant
    Filed: February 25, 2013
    Date of Patent: December 2, 2014
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Masayuki Sakakura, Hiromichi Godo, Kaoru Tsuchiya
  • Patent number: 8895976
    Abstract: Manufactured is a transistor including an oxide semiconductor layer, a source electrode layer and a drain electrode layer overlapping with part of the oxide semiconductor layer, a gate insulating layer overlapping with the oxide semiconductor layer, the source electrode layer, and the drain electrode layer, and a gate electrode overlapping with part of the oxide semiconductor layer with the gate insulating layer provided therebetween, wherein, after the oxide semiconductor layer which is to be a channel formation region is irradiated with light and the light irradiation is stopped, a relaxation time of carriers in photoresponse characteristics of the oxide semiconductor layer has at least two kinds of modes: ?1 and ?2, ?1<?2 is satisfied, and ?2 is 300 seconds or less. In addition, a semiconductor device including the transistor is manufactured.
    Type: Grant
    Filed: June 20, 2011
    Date of Patent: November 25, 2014
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Masashi Tsubuku, Takayuki Inoue, Suzunosuke Hiraishi, Erumu Kikuchi, Hiromichi Godo, Shuhei Yoshitomi, Koki Inoue, Akiharu Miyanaga, Shunpei Yamazaki
  • Patent number: 8877569
    Abstract: An object is to provide a semiconductor device provided with a thin film transistor having excellent electric characteristics using an oxide semiconductor layer. An In—Sn—O-based oxide semiconductor layer including SiOX is used for a channel formation region. In order to reduce contact resistance between the In—Sn—O-based oxide semiconductor layer including SiOX and a wiring layer formed from a metal material having low electric resistance, a source region or drain region is formed between a source electrode layer or drain electrode layer and the In—Sn—O-based oxide semiconductor layer including SiOX. The source region or drain region and a pixel region are formed using an In—Sn—O-based oxide semiconductor layer which does not include SiOX.
    Type: Grant
    Filed: April 25, 2012
    Date of Patent: November 4, 2014
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Yoshiaki Oikawa, Hotaka Maruyama, Hiromichi Godo, Daisuke Kawae, Shunpei Yamazaki
  • Publication number: 20140319519
    Abstract: An oxide semiconductor layer in which “safe” traps exist exhibits two kinds of modes in photoresponse characteristics. By using the oxide semiconductor layer, a transistor in which light deterioration is suppressed to the minimum and the electric characteristics are stable can be achieved. The oxide semiconductor layer exhibiting two kinds of modes in photoresponse characteristics has a photoelectric current value of 1 pA to 10 nA inclusive. When the average time ?1 until which carriers are captured by the “safe” traps is large enough, there are two kinds of modes in photoresponse characteristics, that is, a region where the current value falls rapidly and a region where the current value falls gradually, in the result of a change in photoelectric current over time.
    Type: Application
    Filed: July 14, 2014
    Publication date: October 30, 2014
    Inventors: Takayuki Inoue, Masashi Tsubuku, Suzunosuke Hiraishi, Junichiro Sakata, Erumu Kikuchi, Hiromichi Godo, Akiharu Miyanaga, Shunpei Yamazaki
  • Patent number: 8860021
    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: December 17, 2012
    Date of Patent: October 14, 2014
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Atsuo Isobe, Hiromichi Godo
  • Patent number: 8853690
    Abstract: An object is to provide a transistor including an oxide layer which includes Zn and does not include a rare metal such as In or Ga. Another object is to reduce an off current and stabilize electric characteristics in the transistor including an oxide layer which includes Zn. A transistor including an oxide layer including Zn is formed by stacking an oxide semiconductor layer including insulating oxide over an oxide layer so that the oxide layer is in contact with a source electrode layer or a drain electrode layer with the oxide semiconductor layer including insulating oxide interposed therebetween, whereby variation in the threshold voltage of the transistor can be reduced and electric characteristics can be stabilized.
    Type: Grant
    Filed: January 17, 2013
    Date of Patent: October 7, 2014
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Hiromichi Godo, Hideyuki Kishida
  • Publication number: 20140284602
    Abstract: A conventional DRAM needs to be refreshed at an interval of several tens of milliseconds to hold data, which results in large power consumption. In addition, a transistor therein is frequently turned on and off; thus, deterioration of the transistor is also a problem. These problems become significant as the memory capacity increases and transistor miniaturization advances. A transistor is provided which includes an oxide semiconductor and has a trench structure including a trench for a gate electrode and a trench for element isolation. Even when the distance between a source electrode and a drain electrode is decreased, the occurrence of a short-channel effect can be suppressed by setting the depth of the trench for the gate electrode as appropriate.
    Type: Application
    Filed: June 9, 2014
    Publication date: September 25, 2014
    Inventors: Shunpei YAMAZAKI, Hiromichi GODO
  • Patent number: 8835917
    Abstract: An object is to provide a semiconductor device having electrical characteristics such as high withstand voltage, low reverse saturation current, and high on-state current. In particular, an object is to provide a power diode and a rectifier which include non-linear elements. An embodiment of the present invention is a semiconductor device including a first electrode, a gate insulating layer covering the first electrode, an oxide semiconductor layer in contact with the gate insulating layer and overlapping with the first electrode, a pair of second electrodes covering end portions of the oxide semiconductor layer, an insulating layer covering the pair of second electrodes and the oxide semiconductor layer, and a third electrode in contact with the insulating layer and between the pair of second electrodes. The pair of second electrodes are in contact with end surfaces of the oxide semiconductor layer.
    Type: Grant
    Filed: August 30, 2011
    Date of Patent: September 16, 2014
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Hiromichi Godo, Satoshi Kobayashi
  • Publication number: 20140252353
    Abstract: Provided is a field-effect transistor (FET) having small off-state current, which is used in a miniaturized semiconductor integrated circuit. The field-effect transistor includes a thin oxide semiconductor which is formed substantially perpendicular to an insulating surface and has a thickness of greater than or equal to 1 nm and less than or equal to 30 nm, a gate insulating film formed to cover the oxide semiconductor, and a strip-like gate which is formed to cover the gate insulating film and has a width of greater than or equal to 10 nm and less than or equal to 100 nm. In this structure, three surfaces of the thin oxide semiconductor are covered with the gate, so that electrons injected from a source or a drain can be effectively removed, and most of the space between the source and the drain can be a depletion region; thus, off-state current can be reduced.
    Type: Application
    Filed: May 27, 2014
    Publication date: September 11, 2014
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Hiromichi Godo, Yasuhiko Takemura
  • Patent number: 8809870
    Abstract: A conventional DRAM needs to be refreshed at an interval of several tens of milliseconds to hold data, which results in large power consumption. In addition, a transistor therein is frequently turned on and off; thus, deterioration of the transistor is also a problem. These problems become significant as the memory capacity increases and transistor miniaturization advances. Another problem is that an increase in memory capacity leads to an increase in the area, despite an attempt at integration through advancement of transistor miniaturization. A transistor is provided which includes an oxide semiconductor and has a trench structure including a trench for a gate electrode and a trench for element isolation. In addition, a plurality of memory elements each including the transistor having a trench structure and including an oxide semiconductor is stacked in a semiconductor device, whereby the circuit area of the semiconductor device can be reduced.
    Type: Grant
    Filed: January 20, 2012
    Date of Patent: August 19, 2014
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Hiromichi Godo