Patents by Inventor Masaki Koyama

Masaki Koyama 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: 7851318
    Abstract: A semiconductor substrate is irradiated with accelerated hydrogen ions, thereby forming a damaged region including a large amount of hydrogen. After a single crystal semiconductor substrate and a supporting substrate are bonded to each other, the semiconductor substrate is heated, so that the single crystal semiconductor substrate is separated in the damaged region. A single crystal semiconductor layer which is separated from the single crystal semiconductor substrate is irradiated with a laser beam. The single crystal semiconductor layer is melted by laser beam irradiation, whereby the single crystal semiconductor layer is recrystallized to recover its crystallinity and to planarized a surface of the single crystal semiconductor layer. After the laser beam irradiation, the single crystal semiconductor layer is heated at a temperature at which the single crystal semiconductor layer is not melted, so that the lifetime of the single crystal semiconductor layer is improved.
    Type: Grant
    Filed: October 16, 2008
    Date of Patent: December 14, 2010
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Masaki Koyama, Fumito Isaka, Akihisa Shimomura, Junpei Momo
  • Publication number: 20100291754
    Abstract: A semiconductor substrate is irradiated with accelerated hydrogen ions, thereby forming a damaged region including a large amount of hydrogen. After a single crystal semiconductor substrate and a supporting substrate are bonded to each other, the semiconductor substrate is heated, so that the single crystal semiconductor substrate is separated in the damaged region. A single crystal semiconductor layer which is separated from the single crystal semiconductor substrate is irradiated with a laser beam. The single crystal semiconductor layer is melted by laser beam irradiation, whereby the single crystal semiconductor layer is recrystallized to recover its crystallinity and to planarized a surface of the single crystal semiconductor layer. After the laser beam irradiation, the single crystal semiconductor layer is heated at a temperature at which the single crystal semiconductor layer is not melted, so that the lifetime of the single crystal semiconductor layer is improved.
    Type: Application
    Filed: July 27, 2010
    Publication date: November 18, 2010
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Masaki KOYAMA, Fumito ISAKA, Akihisa SHIMOMURA, Junpei MOMO
  • Patent number: 7816232
    Abstract: An object is to provide a uniform semiconductor substrate in which defective bonding is reduced. A further object is to manufacture the semiconductor substrate with a high yield. A first substrate and a second substrate are bonded in a reduced-pressure atmosphere by placing the first substrate at a certain region surrounded by an airtight holding mechanism provided over a support to surround the certain region of a surface of the support; placing the second substrate so as to come to be in contact with the airtight holding mechanism to ensure airtightness of a space surrounded by the support, the airtight holding mechanism, and the second substrate; evacuating the space whose airtightness is secured, thereby reducing an pressure in the space; disposing the second substrate in close contact with the first substrate using difference between the pressure in the space and outside atmospheric pressure; and performing heat treatment.
    Type: Grant
    Filed: November 21, 2008
    Date of Patent: October 19, 2010
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Akihisa Shimomura, Masaki Koyama, Satohiro Okamoto
  • Publication number: 20100248444
    Abstract: A single crystal semiconductor separated from a single crystal semiconductor substrate is formed partly over a supporting substrate with a buffer layer provided therebetween. The single crystal semiconductor is separated from the single crystal semiconductor substrate by irradiation with accelerated ions, formation of a fragile layer by the ion irradiation, and heat treatment. A non-single crystal semiconductor layer is formed over the single crystal semiconductor and irradiated with a laser beam to be crystallized, whereby an SOI substrate is manufactured.
    Type: Application
    Filed: March 23, 2010
    Publication date: September 30, 2010
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Shunpei Yamazaki, Masaki Koyama, Kosei Noda, Kenichiro Makino, Hideto Ohnuma, Kosei Nei
  • Publication number: 20100140658
    Abstract: In a method of manufacturing a semiconductor device, a semiconductor substrate of a first conductivity type having first and second surfaces is prepared. Second conductivity type impurities for forming a collector layer are implanted to the second surface using a mask that has an opening at a portion where the collector layer will be formed. An oxide layer is formed by enhanced-oxidizing the collector layer. First conductivity type impurities for forming a first conductivity type layer are implanted to the second surface using the oxide layer as a mask. A support base is attached to the second surface and a thickness of the semiconductor substrate is reduced from the first surface. An element part including a base region, an emitter region, a plurality of trenches, a gate insulating layer, a gate electrode, and a first electrode is formed on the first surface of the semiconductor substrate.
    Type: Application
    Filed: November 30, 2009
    Publication date: June 10, 2010
    Applicant: DENSO CORPORATION
    Inventors: Masaki Koyama, Yutaka Fukuda
  • Publication number: 20100120224
    Abstract: An object is to provide a method for manufacturing an SOI substrate including a single crystal silicon film whose plane orientation is (100) and a single crystal silicon film whose plane orientation is (110) with high yield. A first single crystal silicon substrate whose plane orientation is (100) is doped with first ions to form a first embrittlement layer. A second single crystal silicon substrate whose plane orientation is (110) is doped with second ions to selectively form a second embrittlement layer. Only part of the first single crystal silicon substrate is separated along the first embrittlement layer by first heat treatment, thereby forming a first single crystal silicon film. A region of the second single crystal silicon substrate, in which the second embrittlement layer is not formed, is removed. Part of the second single crystal silicon substrate is separated along the second embrittlement layer by second heat treatment, thereby forming a second single crystal silicon film.
    Type: Application
    Filed: November 10, 2009
    Publication date: May 13, 2010
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Akihisa SHIMOMURA, Masaki KOYAMA, Yasuhiro JINBO, Naoki OKUNO
  • Publication number: 20100093153
    Abstract: To prevent, in the case of irradiating a single crystal semiconductor layer with a laser beam, an impurity element from being taken into the single crystal semiconductor layer at the time of laser irradiation.
    Type: Application
    Filed: October 8, 2009
    Publication date: April 15, 2010
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Masaki Koyama, Junpei Momo, Eiji Higa, Hiroaki Honda, Tamae Moriwaka, Akihisa Shimomura
  • Publication number: 20100084734
    Abstract: To provide a semiconductor substrate in which a semiconductor element having favorable crystallinity and high performance can be formed. A single crystal semiconductor substrate having an embrittlement layer and a base substrate are bonded with an insulating layer interposed therebetween; the single crystal semiconductor substrate is separated along the embrittlement layer by heat treatment; a single crystal semiconductor layer is fixed to the base substrate; the single crystal semiconductor layer is irradiated with a laser beam; the single crystal semiconductor layer is in a partially melted state to be recrystallized; and crystal defects are repaired. In addition, the energy density of a laser beam with which the best crystallinity of the single crystal semiconductor layer is obtained is detected by a microwave photoconductivity decay method.
    Type: Application
    Filed: September 29, 2009
    Publication date: April 8, 2010
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Junpei Momo, Kosei Nei, Hiroaki Honda, Masaki Koyama, Akihisa Shimomura
  • Publication number: 20100087047
    Abstract: To increase adhesion between a single crystal semiconductor layer and a base substrate and to reduce bonding defects therebetween. To perform radical treatment on a surface of a semiconductor substrate to form a first insulating film on the semiconductor substrate; irradiate the semiconductor substrate with accelerated ions through the first insulating film to form an embrittlement region in the semiconductor substrate; form a second insulating film on the first insulating film; perform heat treatment after bonding a surface of the second insulating film and a surface of the base substrate to perform separation along the embrittlement region so that a semiconductor layer is formed over the base substrate with the first and second insulating films interposed therebetween; etch the semiconductor layer; and irradiate the semiconductor layer on which the etching is performed with a laser beam.
    Type: Application
    Filed: September 29, 2009
    Publication date: April 8, 2010
    Inventors: Akihisa Shimomura, Masaki Koyama, Eiji Higa
  • Patent number: 7595849
    Abstract: The present invention is to reduce display unevenness in a display device caused by dispersion of energy density of a laser beam. It is difficult for a periodical pattern to be recognized as display unevenness in display image. The display device of the present invention can visually reduce the display unevenness in the display image by utilizing the visual advantage described above. The display device can be manufactured using a TFT array substrate in which electric characteristic of plural TFTs arranged in a line in the minor axis direction of an linear shaped laser beam periodically fluctuates depending on the place in which each TFT is formed.
    Type: Grant
    Filed: January 31, 2008
    Date of Patent: September 29, 2009
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Masaki Koyama
  • Publication number: 20090230503
    Abstract: Methods for manufacturing a semiconductor substrate and a semiconductor device by which a high-performance semiconductor element can be formed are provided. A single crystal semiconductor substrate including an embrittlement layer and a base substrate are bonded to each other with an insulating layer interposed therebetween, and the single crystal semiconductor substrate is separated along the embrittlement layer by heat treatment to fix a single crystal semiconductor layer over the base substrate. Next, a plurality of regions of a monitor substrate are irradiated with laser light under conditions of different energy densities, and carbon concentration distribution and hydrogen concentration distribution in a depth direction of each region of the single crystal semiconductor layer which has been irradiated with the laser light is measured.
    Type: Application
    Filed: March 12, 2009
    Publication date: September 17, 2009
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Akihisa SHIMOMURA, Masaki KOYAMA, Motoki NAKASHIMA
  • Publication number: 20090189181
    Abstract: A semiconductor device having an IGBT includes: a substrate; a drift layer and a base layer on the substrate; trenches penetrating the base layer to divide the base layer into base parts; an emitter region in one base part; a gate element in the trenches; an emitter electrode; and a collector electrode. The one base part provides a channel layer, and another base part provides a float layer having no emitter region. The gate element includes a gate electrode next to the channel layer and a dummy gate electrode next to the float layer. The float layer includes a first float layer adjacent to the channel layer and a second float layer apart from the channel layer. The dummy gate electrode and the first float layer are coupled with a first float wiring on the base layer. The dummy gate electrode is isolated from the second float layer.
    Type: Application
    Filed: January 27, 2009
    Publication date: July 30, 2009
    Applicants: DENSO CORPORATION, Fuji Electric Device Technology Co., Ltd.
    Inventors: Masaki Koyama, Yoshifumi Okabe, Makoto Asai, Takeshi Fujii, Koh Yoshikawa
  • Publication number: 20090137095
    Abstract: An object is to provide a uniform semiconductor substrate in which defective bonding is reduced. A further object is to manufacture the semiconductor substrate with a high yield. A first substrate and a second substrate are bonded in a reduced-pressure atmosphere by placing the first substrate at a certain region surrounded by an airtight holding mechanism provided over a support to surround the certain region of a surface of the support; placing the second substrate so as to come to be in contact with the airtight holding mechanism to ensure airtightness of a space surrounded by the support, the airtight holding mechanism, and the second substrate; evacuating the space whose airtightness is secured, thereby reducing an pressure in the space; disposing the second substrate in close contact with the first substrate using difference between the pressure in the space and outside atmpspheric pressure; and performing heat treatment.
    Type: Application
    Filed: November 21, 2008
    Publication date: May 28, 2009
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Akihisa SHIMOMURA, Masaki KOYAMA, Satohiro OKAMOTO
  • Publication number: 20090117692
    Abstract: A single crystal semiconductor substrate bonded over a supporting substrate with a buffer layer interposed therebetween and having a separation layer is heated to separate the single crystal semiconductor substrate using the separation layer or a region near the separation layer as a separation plane, thereby forming a single crystal semiconductor layer over the supporting substrate. The single crystal semiconductor layer is irradiated with a laser beam to re-single-crystallize the single crystal semiconductor layer through melting. An impurity element is selectively added into the single crystal semiconductor layer to form a pair of impurity regions and a channel formation region between the pair of impurity regions. The single crystal semiconductor layer is heated at temperature which is equal to or higher than 400° C. and equal to or lower than a strain point of the supporting substrate and which does not cause melting of the single crystal semiconductor layer.
    Type: Application
    Filed: October 30, 2008
    Publication date: May 7, 2009
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Masaki Koyama, Fumito Isaka, Akihisa Shimomura, Junpei Momo, Shunpei Yamazaki
  • Publication number: 20090115029
    Abstract: A semiconductor substrate is irradiated with accelerated hydrogen ions, thereby forming a damaged region including a large amount of hydrogen. After a single crystal semiconductor substrate and a supporting substrate are bonded to each other, the semiconductor substrate is heated, so that the single crystal semiconductor substrate is separated in the damaged region. A single crystal semiconductor layer which is separated from the single crystal semiconductor substrate is irradiated with a laser beam. The single crystal semiconductor layer is melted by laser beam irradiation, whereby the single crystal semiconductor layer is recrystallized to recover its crystallinity and to planarized a surface of the single crystal semiconductor layer.
    Type: Application
    Filed: October 16, 2008
    Publication date: May 7, 2009
    Applicant: Semiconductor Energy Laboratory Co., ltd.
    Inventors: Masaki Koyama, Fumito Isaka, Akihisa Shimomura, Junpei Momo
  • Publication number: 20090111244
    Abstract: A single crystal semiconductor substrate is irradiated with ions that are generated by exciting a hydrogen gas and are accelerated with an ion doping apparatus, thereby forming a damaged region that contains a large amount of hydrogen. After the single crystal semiconductor substrate and a supporting substrate are bonded, the single crystal semiconductor substrate is heated to be separated along the damaged region. While a single crystal semiconductor layer separated from the single crystal semiconductor substrate is heated, this single crystal semiconductor layer is irradiated with a laser beam. The single crystal semiconductor layer undergoes re-single-crystallization by being melted through laser beam irradiation, thereby recovering its crystallinity and planarizing the surface of the single crystal semiconductor layer.
    Type: Application
    Filed: October 7, 2008
    Publication date: April 30, 2009
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Shunpei YAMAZAKI, Junpei MOMO, Fumito ISAKA, Eiji HIGA, Masaki KOYAMA, Akihisa SHIMOMURA
  • Publication number: 20090016393
    Abstract: It is an object to provide a laser apparatus, a laser irradiating method and a manufacturing method of a semiconductor device that make laser energy more stable. To attain the object, a part of laser beam emitted from an oscillator is sampled to generate an electric signal that contains as data energy fluctuation of a laser beam. The electric signal is subjected to signal processing to calculate the frequency, amplitude, and phase of the energy fluctuation of the laser beam.
    Type: Application
    Filed: December 18, 2007
    Publication date: January 15, 2009
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hidekazu Miyairi, Akihisa Shimomura, Tamae Takano, Masaki Koyama, Koichiro Tanaka
  • Publication number: 20080149931
    Abstract: The present invention is to reduce display unevenness in a display device caused by dispersion of energy density of a laser beam. It is difficult for a periodical pattern to be recognized as display unevenness in display image. The display device of the present invention can visually reduce the display unevenness in the display image by utilizing the visual advantage described above. The display device can be manufactured using a TFT array substrate in which electric characteristic of plural TFTs arranged in a line in the minor axis direction of an linear shaped laser beam periodically fluctuates depending on the place in which each TFT is formed.
    Type: Application
    Filed: January 31, 2008
    Publication date: June 26, 2008
    Inventor: Masaki Koyama
  • Patent number: 7390728
    Abstract: The present invention is to reduce display unevenness in a display device caused by dispersion of energy density of a laser beam. It is difficult for a periodical pattern to be recognized as display unevenness in display image. The display device of the present invention can visually reduce the display unevenness in the display image by utilizing the visual advantage described above. The display device can be manufactured using a TFT array substrate in which electric characteristic of plural TFTs arranged in a line in the minor axis direction of an linear shaped laser beam periodically fluctuates depending on the place in which each TFT is formed.
    Type: Grant
    Filed: December 24, 2003
    Date of Patent: June 24, 2008
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Masaki Koyama
  • Patent number: 7358165
    Abstract: A crystallizing method that can control the orientation of crystal grains with the use of a metal element for promoting crystallization. In the method, the metal element for promoting crystallization is added to selectively form a crystalline semiconductor film, and the crystalline semiconductor film is irradiated with a pulsed laser to form a film having small crystal grains in grid pattern at a regular intervals wherein adjacent crystal grains have the same orientation.
    Type: Grant
    Filed: July 9, 2004
    Date of Patent: April 15, 2008
    Assignee: Semiconductor Energy Laboratory Co., Ltd
    Inventors: Hironobu Shoji, Akihisa Shimomura, Masaki Koyama