Patents by Inventor Tsuyoshi Horikawa

Tsuyoshi Horikawa 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: 6110283
    Abstract: A chemical vapor deposition apparatus to reduce generation of contaminants such as residues within the apparatus can be obtained. The chemical vapor deposition apparatus includes a CVD source container, a vaporizer and reaction unit. The vaporizer has a nozzle attached thereto. The nozzle has a tip portion and a thick portion. The reaction unit includes a mixing unit. The mixing unit includes an oxidizer supply pipe as well as a heating portion having a helical side groove and heating means. Reaction unit further includes a reaction chamber surrounded by a wall surface. The inside of the wall surface is covered with an inactive cover layer, and the wall surface is heated to a temperature range of 300-500.degree. C.
    Type: Grant
    Filed: August 15, 1997
    Date of Patent: August 29, 2000
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Mikio Yamamuka, Takaaki Kawahara, Masayoshi Tarutani, Tsuyoshi Horikawa
  • Patent number: 6110291
    Abstract: A thin film forming apparatus using laser includes a chamber (1), a target (5) placed therein, a laser light source (10) for emitting laser beam to target (5), and a substrate holder (3). When target (5) is irradiated with laser beam (16), a plume (15) is generated, and materials included in plume (15) are deposited on the surface of a substrate (2) held by substrate holder (3). The laser beam emitted from laser light source (10) has its cross section shaped to a desired shape when passed through a shielding plate (4804), for example, so that the surface of the target (5) is irradiated with the beam having uniform light intensity distribution. Therefore, a plume (15) having uniform density distribution of active particles is generated, and therefore a thin film of high quality can be formed over a wide area with uniform film quality, without damaging the substrate.
    Type: Grant
    Filed: August 7, 1996
    Date of Patent: August 29, 2000
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kenyu Haruta, Koichi Ono, Hitoshi Wakata, Mutsumi Tsuda, Yoshio Saito, Keisuke Nanba, Kazuyoshi Kojima, Tetsuya Takami, Akihiro Suzuki, Tomohiro Sasagawa, Kenichi Kuroda, Toshiyuki Oishi, Yukihiko Wada, Akihiko Furukawa, Yasuji Matsui, Akimasa Yuki, Takaaki Kawahara, Hideki Yabe, Taisuke Furukawa, Kouji Kise, Noboru Mikami, Tsuyoshi Horikawa, Tetsuo Makita, Kazuo Kuramoto, Naohiko Fujino, Hiroshi Kuroki, Tetsuo Ogama, Junji Tanimura
  • Patent number: 6101085
    Abstract: There is provided a (Ba, Sr) TiO.sub.3 film of higher dielectric constant and less leakage current for serving as a dielectric thin film of a capacitor in a semiconductor memory. DPM (dipivaloylmethanato) compounds of Ba, Sr and Ti are dissolved in THF (tetrahydrofuran) to obtain Ba(DPM).sub.2 /THF, Sr(DPM).sub.2 /THF and TiO(DPM).sub.2 /THF solutions which are used as source material solutions. A (Ba, Sr) TiO.sub.3 film is formed by a CVD method while increasing a relative percentage of a Ti source material flow rate to a sum of Ba source material flow rate and Sr source material flow rate. The film formation is carried out in multiple steps, and annealing is applied in each step after deposition of the film.
    Type: Grant
    Filed: September 12, 1997
    Date of Patent: August 8, 2000
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takaaki Kawahara, Mikio Yamamuka, Tetsuro Makita, Tsuyoshi Horikawa, Akimasa Yuuki, Teruo Shibano
  • Patent number: 6049103
    Abstract: A thin film capacitor structure of a random access memory includes plurality of capacitors formed on an interlayer insulating film. The capacitor structure includes a plurality of lower electrodes formed on the interlayer insulating film, a first dielectric film formed over the plurality of lower electrodes and portions of the interlayer insulating film between lower electrodes, a second dielectric film formed on the first dielectric film, and an upper electrode formed on the second dielectric layer. A silicon oxide film is formed at the step portions of the first dielectric film which result at the periphery of the lower electrodes to prevent leakage current between adjacent capacitors.
    Type: Grant
    Filed: March 22, 1996
    Date of Patent: April 11, 2000
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Tsuyoshi Horikawa, Yoshikazu Tsunemine, Takeharu Kuroiwa, Tetsuro Makita, Noboru Mikami
  • Patent number: 5989635
    Abstract: There is provided a (Ba, Sr) TiO.sub.3 film of higher dielectric constant and less leakage current for serving as a dielectric thin film of a capacitor in a semiconductor memory. DPM (dipivaloylmethanato) compounds of Ba, Sr and Ti are dissolved in THF (tetrahydrofuran) to obtain Ba(DPM).sub.2 /THF, Sr(DPM).sub.2 /THF and TiO(DPM).sub.2 /THF solutions which are used as source material solutions. A (Ba, Sr) TiO.sub.3 film is formed by a CVD method while increasing a relative percentage of a Ti source material flow rate to a sum of Ba source material flow rate and Sr source material flow rate. The film formation is carried out in multiple steps, and annealing is applied in each step after deposition of the film.
    Type: Grant
    Filed: September 12, 1997
    Date of Patent: November 23, 1999
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takaaki Kawahara, Mikio Yamamuka, Tetsuro Makita, Tsuyoshi Horikawa, Akimasa Yuuki, Teruo Shibano
  • Patent number: 5939744
    Abstract: In a thin film capacitor of a random access memory including a lower electrode, a dielectric film and an upper electrode, generation of defects in the dielectric film is suppressed. In another way, impurity diffusion into the dielectric film is prevented. In still another way, lattice matching of the dielectric film and the electrodes is realized. Thus, a reduced dielectric constant of the capacitor is prevented, and a quality of the semiconductor device is increased.
    Type: Grant
    Filed: October 17, 1997
    Date of Patent: August 17, 1999
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Tsuyoshi Horikawa, Yoshikazu Tsunemine, Takeharu Kuroiwa, Tetsuro Makita, Noboru Mikami
  • Patent number: 5882410
    Abstract: There is provided a (Ba, Sr) TiO.sub.3 film of higher dielectric constant and less leakage current for serving as a dielectric thin film of a capacitor in a semiconductor memory. DPM (dipivaloylmethanato) compounds of Ba, Sr and Ti are dissolved in THF (tetrahydrofuran) to obtain Ba(DPM).sub.2 /THF, Sr(DPM).sub.2 /THF and TiO(DPM).sub.2 /THF solutions which are used as source material solutions. A (Ba, Sr) TiO.sub.3 film is formed by a CVD method while increasing a relative percentage of a Ti source material flow rate to a sum of Ba source material flow rate and Sr source material flow rate. The film formation is carried out in multiple steps, and annealing is applied in each step after deposition of the film.
    Type: Grant
    Filed: July 15, 1998
    Date of Patent: March 16, 1999
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takaaki Kawahara, Mikio Yamamuka, Tetsuro Makita, Tsuyoshi Horikawa, Akimasa Yuuki, Teruo Shibano
  • Patent number: 5834060
    Abstract: There is provided a (Ba, Sr) TiO.sub.3 film of higher dielectric constant and less leakage current for serving as a dielectric thin film of a capacitor in a semiconductor memory. DPM (dipivaloylmethanato) compounds of Ba, Sr and Ti are dissolved in THF (tetrahydrofuran) to obtain Ba(DPM).sub.2 /THF, Sr(DPM).sub.2 /THF and TiO(DPM).sub.2 /THF solutions which are used as source material solutions. A (Ba, Sr) TiO.sub.3 film is formed by a CVD method while increasing a relative percentage of a Ti source material flow rate to a sum of Ba source material flow rate and Sr source material flow rate. The film formation is carried out in multiple steps, and annealing is applied in each step after deposition of the film.
    Type: Grant
    Filed: October 1, 1996
    Date of Patent: November 10, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takaaki Kawahara, Mikio Yamamuka, Tetsuro Makita, Tsuyoshi Horikawa, Akimasa Yuuki, Teruo Shibano
  • Patent number: 5281806
    Abstract: A liquid crystal light valve has a photoconductive layer between a pair of electrodes, and a liquid crystal layer. The resistivity of the photoconductive layer at the portion which is irradiated with light is reduced by partial light irradiation. By applying a voltage between the electrodes in this state, the voltage is applied to the liquid crystal layer in the portion which is irradiated with light and the crystalline structure at this portion is changed, thereby enabling image data writing. The photoconductive layer is a laminate of an amorphous Si film and an inorganic insulating film disposed on the electrode side, which structure suppresses the carrier injection from the electrode to the amorphous Si film. The polarity of a voltage for writing image data into the liquid crystal light valve is inverted for every horizontal scanning operation. That is, writing of black portions on a white background and writing of white portions on a black background are alternately executed.
    Type: Grant
    Filed: April 22, 1993
    Date of Patent: January 25, 1994
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kazuro Nishi, Hajime Nakajima, Masaya Mizunuma, Tatsuo Masumi, Shigeyuki Kaho, Tsuyoshi Horikawa, Shin Tahata
  • Patent number: 5231282
    Abstract: A liquid crystal light valve has a photoconductive layer between a pair of electrodes, and a liquid crystal layer. The resistivity of the photoconductive layer at the portion which is irradiated with light is reduced by partial light irradiation. By applying a voltage between the electrodes in this state, the voltage is applied to the liquid crystal layer in the portion which is irradiated with light and the crystalline structure at this portion is changed, thereby enabling image data writing. The photoconductive layer is a laminate of an amorphous Si film and an inorganic insulating film disposed on the electrode side, which structure suppresses the carrier injection from the electrode to the amorphous Si film. The polarity of a voltage for writing image data into the liquid crystal light valve is inverted for every horizontal scanning operation. That is, writing of black portions on a white background and writing of white portions on a black background are alternately executed.
    Type: Grant
    Filed: January 17, 1992
    Date of Patent: July 27, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kazuro Nishi, Hajime Nakajima, Masaya Mizunuma, Tatsuo Masumi, Shigeyuki Kaho, Tsuyoshi Horikawa, Shin Tahata