Patents by Inventor Takaaki Kawahara

Takaaki Kawahara 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: 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: 6096133
    Abstract: An apparatus for depositing a thin film on a substrate by chemical vapor deposition (CVD) includes a material container for containing a liquid CVD source material; a material feeder for feeding the liquid CVD source material from the material container to a vaporizer while keeping the CVD source material liquid; a vaporizer for vaporizing the liquid CVD source material fed from the material feeder by heating the liquid CVD source material to a high temperature to form a CVD source material gas; a reaction chamber connected to the vaporizer by a pipe for forming a thin film on a substrate using the CVD source material gas; and a thermostatic box surrounding the reaction chamber, wherein both of the vaporizer and piping connecting the vaporizer to the reaction chamber are located within the thermostatic box.
    Type: Grant
    Filed: January 6, 2000
    Date of Patent: August 1, 2000
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Akimasa Yuuki, Takaaki Kawahara, Tetsuro Makita, Mikio Yamamuka, Koichi Ono, Tomonori Okudaira
  • Patent number: 6033732
    Abstract: A method of depositing a thin film on a substrate by chemical vapor deposition (CVD) including feeding a liquid CVD source material, including a solution in which at least one organometallic complex is dissolved in a solvent, at a constant flow rate to a vaporizer while keeping the CVD source material in a liquid state; vaporizing the liquid CVD source material by heating to form a CVD source material gas; and forming a thin film of a metal oxide on a substrate using the CVD material source gas in a reaction chamber, the thin film including at least titanium, including using TTIP and TiO(Dpm).sub.2 together as the organometallic complex.
    Type: Grant
    Filed: April 30, 1998
    Date of Patent: March 7, 2000
    Assignee: Mitsushita Denki Kabushiki Kaisha
    Inventors: Akimasa Yuuki, Takaaki Kawahara, Tetsuro Makita, Mikio Yamamuka, Koichi Ono, Tomonori Okudaira
  • Patent number: 6022811
    Abstract: A CVD method including the steps of: setting a semiconductor wafer on a heating stage within a CVD reaction chamber; and emitting CVD reaction gas towards at least the central major region of the wafer from a first gas blowing region of a gas head provided opposing the wafer and having a plurality of gas blowing regions separated from each other, and simultaneously emitting inert gas towards the peripheral region of the wafer from a second gas blowing region of the gas head, while maintaining the temperature of the wafer at a predetermined temperature, and while maintaining the pressure of the CVD reaction chamber within a range from 100 Torr to atmospheric pressure; whereby a CVD film of high quality can be formed in uniform thickness on the wafer, and the consumed amount of reaction gas and the amount of undesirable precipitated particles can be reduced.
    Type: Grant
    Filed: June 18, 1997
    Date of Patent: February 8, 2000
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Akimasa Yuuki, Takaaki Kawahara, Kouitirou Tsutahara, Touru Yamaguchi
  • 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: 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: 5776254
    Abstract: A chemical vapor deposition (CVD) apparatus for depositing a thin film on a substrate by CVD has a material container for containing a liquid CVD source material, a material feeder for feeding the liquid CVD source material to a vaporizer for vaporizing the liquid CVD source material, and a reaction chamber for forming the thin film on the substrate using the CVD source material gas. Both the vaporizer and piping between the vaporizer and the reaction chamber are located in a thermostatic box surrounding the reaction chamber. Thus, the structure of the apparatus is simplified and also the heat efficiency of the apparatus is improved.
    Type: Grant
    Filed: December 27, 1995
    Date of Patent: July 7, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Akimasa Yuuki, Takaaki Kawahara, Tetsuro Makita, Mikio Yamamuka, Koichi Ono, Tomonori Okudaira
  • Patent number: 5760366
    Abstract: A thin film forming apparatus using a laser includes a chamber (1), a target (5) placed therein, a laser light source (10) for emitting a laser beam to target 5, and a substrate holder (3). When the target is irradiated with a laser beam, a plume (15) is generated, and materials included in plume 15 are deposited on the surface of a substrate (2) held by the substrate holder (3). A magnetic field is generated to direct the plume. The magnetic field can be parallel to the surface of the substrate or in another embodiment a cusp magnetic field can be used (see FIG. 130).
    Type: Grant
    Filed: August 7, 1996
    Date of Patent: June 2, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kenyu Haruta, Koichi Ono, Mutsumi Tsuda, Takaaki Kawahara, Taisuke Furukawa
  • Patent number: 5669976
    Abstract: A CVD method including the steps of: setting a semiconductor wafer on a heating stage within a CVD reaction chamber; and emitting CVD reaction gas towards at least the central major region of the wafer from a first gas blowing region of a gas head provided opposing the wafer and having a plurality of gas blowing regions separated from each other, and simultaneously emitting inert gas towards the peripheral region of the wafer from a second gas blowing region of the gas head, while maintaining the temperature of the wafer at a predetermined temperature, and while maintaining the pressure of the CVD reaction chamber within a range from 100 Torr to atmospheric pressure; whereby a CVD film of high quality can be formed in uniform thickness on the wafer, and the consumed amount of reaction gas and the amount of undesirable precipitated particles can be reduced.
    Type: Grant
    Filed: February 24, 1994
    Date of Patent: September 23, 1997
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Akimasa Yuuki, Takaaki Kawahara, Kouitirou Tsutahara, Touru Yamaguchi