Patents by Inventor Masahito Kodama

Masahito Kodama 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: 20240132253
    Abstract: The present invention provides a sheet material container being made of a sheet material and including a body portion and a bottom portion that is to be disposed on a placement surface, and the sheet material including a plurality of film layers. A body portion sheet that constitutes the body portion includes a bonding portion where peripheral edge portions of the sheet materials are bonded. In a bottom surface sheet that constitutes the bottom portion, a non-adhesive region is provided in the plurality of film layers. The non-adhesive region forms a bottom filler-filled portion. The bottom filler-filled portion extends annularly around a non-filled portion, and includes at least three protruding leg portions that are to be placed on the placement surface so as to allow the container to stand by itself. The protruding leg portions protrude toward the placement surface past other portions in the bottom filler-filled portion due a leg forming portion.
    Type: Application
    Filed: December 11, 2023
    Publication date: April 25, 2024
    Applicant: Kao Corporation
    Inventors: Yoshinori INAGAWA, Mitsugu IWATSUBO, Takahiro OTSUKA, Masahito CHIWAKI, Daisuke KODAMA
  • Patent number: 10381469
    Abstract: A semiconductor device includes a switching device having: a substrate configured by a semi-insulating material or a semiconductor; a channel forming layer on the substrate that is configured by a compound semiconductor mainly having a group III nitride; a gate structure configured by a gate electrode on the channel forming layer with a gate insulating film interposed therebetween; and a source electrode and a drain electrode on the channel forming layer at both sides of the gate structure respectively, a collapse inhibiting layer on the channel forming layer in an element region of the channel forming layer where the switching device is arranged that is configured by an insulating material; and a leakage inhibiting layer on the channel forming layer in an element isolation region of the channel forming layer surrounding the element region that is configured by an insulating material different from that of the collapse inhibiting layer.
    Type: Grant
    Filed: August 28, 2014
    Date of Patent: August 13, 2019
    Assignee: DENSO CORPORATION
    Inventors: Yoshinori Tsuchiya, Shinichi Hoshi, Kazuyoshi Tomita, Kenji Itoh, Masahito Kodama, Tsutomu Uesugi
  • Publication number: 20160372587
    Abstract: A semiconductor device includes a switching device having: a substrate configured by a semi-insulating material or a semiconductor; a channel forming layer on the substrate that is configured by a compound semiconductor mainly having a group III nitride; a gate structure configured by a gate electrode on the channel forming layer with a gate insulating film interposed therebetween; and a source electrode and a drain electrode on the channel forming layer at both sides of the gate structure respectively, a collapse inhibiting layer on the channel forming layer in an element region of the channel forming layer where the switching device is arranged that is configured by an insulating material; and a leakage inhibiting layer on the channel forming layer in an element isolation region of the channel forming layer surrounding the element region that is configured by an insulating material different from that of the collapse inhibiting layer.
    Type: Application
    Filed: August 28, 2014
    Publication date: December 22, 2016
    Inventors: Yoshinori TSUCHIYA, Shinichi HOSHI, Kazuyoshi TOMITA, Kenji ITOH, Masahito KODAMA, Tsutomu UESUGI
  • Publication number: 20110316049
    Abstract: Provided are a vertical nitride semiconductor device in which occurrence of leak currents can be suppressed, and a method for manufacturing such nitride semiconductor device. A nitride semiconductor device, which is a vertical HEMT, is provided with an n? type GaN first nitride semiconductor layer, p+ type GaN second nitride semiconductor layers, an n? type GaN third nitride semiconductor layer, and an n? type AlGaN fourth nitride semiconductor layer that is in hetero junction with a front surface of the third nitride semiconductor layer. Openings that penetrate the third nitride semiconductor layer and reach front surfaces of the second nitride semiconductor layers are provided at positions isolated from the peripheral edge of the third nitride semiconductor layer. Source electrodes are provided in the openings. Etching damage that is in contact with the source electrodes is surrounded by a region where no etching damage is formed.
    Type: Application
    Filed: March 2, 2009
    Publication date: December 29, 2011
    Applicants: Kabushiki Kaisha Toyota Chuo Kenkyusho, Toyota Jidosha Kabushiki Kaisha
    Inventors: Masahiro Sugimoto, Narumasa Soejima, Tsutomu Uesugi, Masahito Kodama, Eiko Ishii
  • Patent number: 7696071
    Abstract: The invention provides a method for producing a group III nitride based semiconductor having a reduced number of crystal defects. A GaN layer 2 is epitaxially grown on a sapphire substrate 1 having C-plane as a main plane (FIG. 1A). Then, the layer is wet-etched by use of a 25% aqueous TMAH solution at 85° C. for one hour, to thereby form an etch pit 4 (FIG. 1B). Then, a GaN layer 5 is grown on the GaN layer 2 through the ELO method (FIG. 1C). The thus-formed GaN layer 5 has a screw dislocation density lower than that of the GaN layer 2.
    Type: Grant
    Filed: October 24, 2007
    Date of Patent: April 13, 2010
    Assignees: Kabushiki Kaisha Toyota Chuo Kenkyusho, Toyota Jidosha Kabushiki Kaisha
    Inventors: Masahito Kodama, Eiko Hayashi, Masahiro Sugimoto
  • Publication number: 20080142845
    Abstract: A HEMT has a drain region adapted to be electrically connected to a high voltage of an electric source, a source region adapted to be electrically connected to a low voltage of the electric source. A first semiconductor region is disposed between the drain region and the source region. A MIS structure and a heterostructure are disposed at a surface of the first semiconductor region. The MIS structure includes a gate electrode that faces a portion of a surface of the first semiconductor region with a gate insulating membrane therebetween. The heterostructure includes a second semiconductor region which makes contact with a rest portion of the surface of the first semiconductor region and has a wider band-gap than the first semiconductor region. The drain region and the source region are capable of being electrically connected with a structure in which the MIS structure 40 and the heterostructure are arranged in series.
    Type: Application
    Filed: December 13, 2007
    Publication date: June 19, 2008
    Inventors: Masahito KODAMA, Eiko HAYASHI, Tsutomu UESUGI, Masahiro SUGIMOTO
  • Publication number: 20080105954
    Abstract: A group III nitride based semiconductor device which has a trench or mesa structure and of which leakage of current and reduction of breakdown voltage are prevented. A GaN layer 2 was grown on a C-plane sapphire substrate 1, and a T-shaped USG film 3 was formed on the GaN layer 2 so that side surfaces of the USG film 3 were arranged parallel to A-plane and M-plane of the GaN layer 2. Thereafter, by using the USG film 3 as a mask, the GaN layer 2 was dry-etched. As is clear from FIGS. 2A and 2B, the M-plane is less roughened as compared with the A-plane. Subsequently, wet-etched was performed by use of an aqueous TMAH solution. As is clear from FIGS. 2C and 2D, roughness of the A-plane and the M-plane are removed, and, particularly, the M-plane assumes a mirror surface. Thus, through provision of M-plane side surfaces of a trench or an etching-formed mesa, leakage of current and reduction of breakdown voltage of a group III nitride based semiconductor device can be prevented.
    Type: Application
    Filed: October 24, 2007
    Publication date: May 8, 2008
    Applicants: KABUSHIKI KAISHA TOYOTA CHUO KENKYUSHO, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masahito KODAMA, Eiko HAYASHI, Masahiro SUGIMOTO
  • Publication number: 20080105903
    Abstract: The invention provides a method for producing a group III nitride based semiconductor having a reduced number of crystal defects. A GaN layer 2 is epitaxially grown on a sapphire substrate 1 having C-plane as a main plane (FIG. 1A). Then, the layer is wet-etched by use of a 25% aqueous TMAH solution at 85° C. for one hour, to thereby form an etch pit 4 (FIG. 1B) Then, a GaN layer 5 is grown on the GaN layer 2 through the ELO method (FIG. 1C). The thus-formed GaN layer 5 has a screw dislocation density lower than that of the GaN layer 2.
    Type: Application
    Filed: October 24, 2007
    Publication date: May 8, 2008
    Applicants: KABUSHIKI KAISHA TOYOTA CHUO KENKYUSHO, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masahito KODAMA, Eiko HAYSASHI, Masahiro SUGIMOTO
  • Patent number: 6844246
    Abstract: A GaN layer 32 grows in vertical direction on a GaN layer 31 where neither a first mask 41m nor a second mask 42m is formed. When thickness of the GaN layer 32 becomes larger than that of the first mask 41m, it began to grown in lateral direction so as to cover the first mask 41m. Because the second mask 42m is not formed on the upper portion of the first mask 41m, the GaN layer 32 grows in vertical direction. On the contrary, at the upper region of the GaN layer 31 where the mask 41m is not formed, the second mask 42m is formed like eaves, the growth of the GaN layer 32 stops and threading dislocations propagated with vertical growth also stops there. The GaN layer 32 grows in vertical direction so as to penetrate the region where neither the first mask 41m nor the second mask 42m is formed. When the height of the GaN layer 32 becomes larger than that of the second mask 42m, the GaN layer 32 begins to grow in lateral direction again and covers the second mask 42m.
    Type: Grant
    Filed: March 19, 2002
    Date of Patent: January 18, 2005
    Assignee: Toyoda Gosei Co., Ltd.
    Inventors: Seiji Nagai, Kazuyoshi Tomita, Masahito Kodama
  • Publication number: 20040087115
    Abstract: A GaN layer 32 grows in vertical direction on a GaN layer 31 where neither a first mask 41m nor a second mask 42m is formed. When thickness of the GaN layer 32 becomes larger than that of the first mask 41m, it began to grown in lateral direction so as to cover the first mask 41m. Because the second mask 42m is not formed on the upper portion of the first mask 41m, the GaN layer 32 grows in vertical direction. On the contrary, at the upper region of the GaN layer 31 where the mask 41m is not formed, the second mask 42m is formed like eaves, the growth of the GaN layer 32 stops and threading dislocations propagated with vertical growth also stops there. The GaN layer 32 grows in vertical direction so as to penetrate the region where neither the first mask 41m nor the second mask 42m is formed. When the height of the GaN layer 32 becomes larger than that of the second mask 42m, the GaN layer 32 begins to grow in lateral direction again and covers the second mask 42m.
    Type: Application
    Filed: November 5, 2003
    Publication date: May 6, 2004
    Inventors: Seiji Nagai, Kazuyoshi Tomita, Masahito Kodama
  • Patent number: 6700175
    Abstract: There is provided a method of manufacturing a vertical semiconductor device including a structural section in which an n−-type semiconductor region and a p−-type semiconductor region are arranged alternately without filling trenches by epitaxial growth. A p−-type silicon layer (13) which becomes a p−-type semiconductor region (12) is formed. An n−-type semiconductor region (11) is formed by diffusing n-type impurities into the p−-type silicon layer (13) through the sidewalls of first trenches (22) formed in the p−-type silicon layer (13).
    Type: Grant
    Filed: December 31, 2001
    Date of Patent: March 2, 2004
    Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho
    Inventors: Masahito Kodama, Tsutomu Uesugi
  • Patent number: 6072215
    Abstract: Disclosed is a semiconductor device including a lateral MOS element which comprises a p-type silicon substrate; a first semiconductor layer of an n-type constituting a drift region; a second semiconductor layer of the p-type selectively provided in the first semiconductor layer, and constituting a body region, in which a channel region is partially formed; a third semiconductor layer of the n-type selectively provided in a surface of the second semiconductor layer, and constituting a source region; a fourth semiconductor layer of the n-type provided in the first semiconductor layer, and constituting a drain region; and a trench gate. The trench gate is constructed such that a trench formed in the first semiconductor layer is filled with a gate electrode with an insulating film interposed therebetween. The trench gate is formed such that at least a bottom thereof is in contact with the semiconductor substrate.
    Type: Grant
    Filed: March 25, 1999
    Date of Patent: June 6, 2000
    Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho
    Inventors: Sachiko Kawaji, Masahito Kodama, Takashi Suzuki, Tsutomu Uesugi
  • Patent number: 5708286
    Abstract: A vertical semiconductor device having an insulated gate structure makes use of a double-gate structure. The double-gate structure dramatically reduces the channel resistance, JFET resistance, and epitaxial resistance of the on-resistance of the power MOSFET, and implements an adequate breakdown voltage due to the effect of gate bias. In principle, a first gate and second gate having mutually facing portions are driven synchronously. This causes first and second channels to be formed in correspondence with first and second gates, and the currents flowing through these first and second channels form the on-current for this power device having a vertical structure.
    Type: Grant
    Filed: March 29, 1996
    Date of Patent: January 13, 1998
    Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho
    Inventors: Tsutomu Uesugi, Masahito Kodama