Patents by Inventor Masatake Nagaya

Masatake Nagaya 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: 20210047750
    Abstract: A seed crystal for single crystal 4H-SiC growth of the present invention is a disk-shaped seed crystal for single crystal 4H-SiC growth having a diameter of more than 150 mm and having a thickness within a range of more than or equal to 1 mm and less than or equal to 0.03 times of the diameter, in which one surface on which the single crystal 4H-SiC is grown is a mirror surface and an Ra of the other surface is more than 10 nm, and an absolute value of magnitude of waviness in a state where the seed crystal is freely deformed so that an internal stress distribution is reduced is less than or equal to 12 ?m.
    Type: Application
    Filed: December 21, 2018
    Publication date: February 18, 2021
    Applicants: SHOWA DENKO K.K., DENSO CORPORATION
    Inventors: Takanori KIDO, Masatake NAGAYA, Hidetaka TAKABA
  • Publication number: 20190035684
    Abstract: In a case where a back surface of an SiC semiconductor wafer, which is provided by a C surface, is covered with a back surface electrode and a scribe line cannot be confirmed, a reference line is formed before dicing. As a result, even when a processing upper surface from which dicing is carried out is a C surface, the dicing can be performed by estimating a scribe line with reference to the reference line. Accordingly, even if the semiconductor wafer is cut at a higher speed than that in the conventional art, a high-quality SiC semiconductor device with less chipping can be manufactured. A blade abrasion can be reduced, and costs can be also reduced.
    Type: Application
    Filed: May 11, 2017
    Publication date: January 31, 2019
    Inventors: Masatake NAGAYA, Jun KAWAI, Yosuke TOMITA
  • Patent number: 8758087
    Abstract: In a wafer processing method, an ingot is sliced into a wafer and the wafer is planarized by polishing a surface of the wafer. When the wafer is planarized, the wafer is disposed on a wafer holder and the wafer is rotated, a heat quantity is applied to a portion of the wafer so as to form a reformed layer at the portion of the wafer, and a polishing tool is brought into contact with the portion of wafer while rotating so as to polish the portion of the wafer.
    Type: Grant
    Filed: May 24, 2011
    Date of Patent: June 24, 2014
    Assignee: DENSO CORPORATION
    Inventors: Kyohei Koutake, Hiromichi Morita, Fumiyoshi Kano, Tetsuji Yamaguchi, Sumitomo Inomata, Masatake Nagaya
  • Publication number: 20110294403
    Abstract: In a wafer processing method, an ingot is sliced into a wafer and the wafer is planarized by polishing a surface of the wafer. When the wafer is planarized, the wafer is disposed on a wafer holder and the wafer is rotated, a heat quantity is applied to a portion of the wafer so as to form a reformed layer at the portion of the wafer, and a polishing tool is brought into contact with the portion of wafer while rotating so as to polish the portion of the wafer.
    Type: Application
    Filed: May 24, 2011
    Publication date: December 1, 2011
    Applicant: DENSO CORPORATION
    Inventors: Kyohei KOUTAKE, Hiromichi Morita, Fumiyoshi Kano, Tetsuji Yamaguchi, Sumitomo Inomata, Masatake Nagaya
  • Patent number: 7763543
    Abstract: A method for manufacturing a silicon carbide semiconductor apparatus is disclosed. According to the method, an element structure is formed on a front surface side of a semiconductor substrate. A rear surface of the semiconductor substrate is grinded or polished in a direction parallel to a flat surface of a table. A front surface of the semiconductor substrate is grinded and polished in a direction parallel to the rear surface after the rear surface of the semiconductor substrate is grinded or polished.
    Type: Grant
    Filed: October 28, 2008
    Date of Patent: July 27, 2010
    Assignee: DENSO CORPORATION
    Inventors: Masatake Nagaya, Yuuichi Takeuchi, Katsuhiro Nagata
  • Publication number: 20090124060
    Abstract: A method for manufacturing a silicon carbide semiconductor apparatus is disclosed. According to the method, an element structure is formed on a front surface side of a semiconductor substrate. A rear surface of the semiconductor substrate is grinded or polished in a direction parallel to a flat surface of a table. A front surface of the semiconductor substrate is grinded and polished in a direction parallel to the rear surface after the rear surface of the semiconductor substrate is grinded or polished.
    Type: Application
    Filed: October 28, 2008
    Publication date: May 14, 2009
    Applicant: DENSO CORPORATION
    Inventors: Masatake Nagaya, Yuuichi Takeuchi, Katsuhiro Nagata
  • Patent number: 6710435
    Abstract: A semiconductor device arrangement includes a plurality of three-dimensional semiconductor units. Each of the three-dimensional semiconductor units includes a semiconductor chip in a shape of a rectangular parallelepiped having six surfaces, and semiconductor devices formed on at least one among the six surfaces. The three-dimensional semiconductor units are mechanically connected and supported, and are electrically connected in a suitable way.
    Type: Grant
    Filed: July 24, 2002
    Date of Patent: March 23, 2004
    Assignee: Denso Corporation
    Inventors: Masatake Nagaya, Toshiyuki Morishita
  • Publication number: 20030032246
    Abstract: A semiconductor device arrangement includes a plurality of three-dimensional semiconductor units. Each of the three-dimensional semiconductor units includes a semiconductor chip in a shape of a rectangular parallelepiped having six surfaces, and semiconductor devices formed on at least one among the six surfaces. The three-dimensional semiconductor units are mechanically connected and supported, and are electrically connected in a suitable way.
    Type: Application
    Filed: July 24, 2002
    Publication date: February 13, 2003
    Inventors: Masatake Nagaya, Toshiyuki Morishita
  • Patent number: 6060344
    Abstract: In a method for producing a semiconductor substrate completed through a bonding process for joining a semiconductor wafer to a support substrate by performing heat treatment thereto in a state in which the semiconductor wafer is closely joined to the support substrate, the method according to the present invention includes the following steps, i.e., a depositing process for depositing a poly-crystal semiconductor which covers all areas of a surface to be bonded on the surface of the semiconductor wafer; a heat treatment process for performing the heat treatment to the semiconductor wafer provided after the depositing process, during a predetermined time under a temperature equal to or higher than the heat treatment temperature at the bonding process; and a polishing process for flattening the surface of the poly-crystal semiconductor provided after the heat treatment process. After the above processes were performed in order, the bonding process is performed after the polishing process.
    Type: Grant
    Filed: August 19, 1998
    Date of Patent: May 9, 2000
    Assignee: Denso Corporation
    Inventors: Masaki Matsui, Masatake Nagaya, Hisayoshi Ohshima
  • Patent number: 5851846
    Abstract: In a dielectric isolation substrate, an end point of a polishing process for selective polishing for forming an SOI layer is detected with a high precision. When polishing a wafer with a polishing pad, the temperature of a region of the polishing pad having polished the wafer at a position immediately thereafter is detected by a temperature sensor and the selective polishing process is ended by discriminating that the rate of variation in the detected temperature has changed from a positive to a negative state and then to a fixed saturated state.
    Type: Grant
    Filed: December 21, 1995
    Date of Patent: December 22, 1998
    Assignee: Nippondenso Co., Ltd.
    Inventors: Masaki Matsui, Masatake Nagaya, Akinari Fukaya, Hiroaki Himi