Patents by Inventor Katsumi Okashita

Katsumi Okashita 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: 7820230
    Abstract: An amount of leakage of a substrate-cooling gas into a vacuum container is measured by using a flow-rate measuring device so that the flow rate of a diluting gas that is the same as the substrate-cooling gas is controlled by a control device or a plasma doping time is prolonged, in accordance with the amount of leakage.
    Type: Grant
    Filed: August 28, 2008
    Date of Patent: October 26, 2010
    Assignee: Panasonic Corporation
    Inventors: Keiichi Nakamoto, Yuichiro Sasaki, Katsumi Okashita, Bunji Mizuno
  • Publication number: 20100255615
    Abstract: A fin-shaped semiconductor region is formed on a substrate, and then the substrate is placed in a chamber. Then, an ignition gas is introduced into a chamber to thereby turn the ignition gas into a plasma, and then a process gas containing an impurity is introduced into the chamber to thereby turn the process gas into a plasma. Then, a bias voltage is applied to the substrate so as to dope the semiconductor region with the impurity after confirming attenuation of an amount of the ignition gas remaining in the chamber.
    Type: Application
    Filed: October 2, 2008
    Publication date: October 7, 2010
    Inventors: Katsumi Okashita, Yuichiro Sasaki, Keiichi Nakamoto, Bunji Mizuno
  • Patent number: 7800165
    Abstract: A semiconductor region having an upper surface and a side surface is formed on a substrate. A first impurity region is formed in an upper portion of the semiconductor region. A second impurity region is formed in a side portion of the semiconductor region. The resistivity of the second impurity region is substantially equal to or smaller than that of the first impurity region.
    Type: Grant
    Filed: February 4, 2008
    Date of Patent: September 21, 2010
    Assignee: Panasonic Corporation
    Inventors: Yuichiro Sasaki, Katsumi Okashita, Keiichi Nakamoto, Hiroyuki Ito, Bunji Mizuno
  • Patent number: 7790586
    Abstract: An impurity region is formed in a surface of a substrate by exposing the substrate to a plasma generated from a gas containing an impurity in a vacuum chamber. In this process, a plasma doping condition is set with respect to a dose of the impurity to be introduced into the substrate so that a first one of doses in a central portion and in a peripheral portion of the substrate is greater than a second one of the doses during an initial period of doping, with the second dose becoming greater than the first dose thereafter.
    Type: Grant
    Filed: November 13, 2007
    Date of Patent: September 7, 2010
    Assignee: Panasonic Corporation
    Inventors: Yuichiro Sasaki, Katsumi Okashita, Hiroyuki Ito, Bunji Mizuno
  • Publication number: 20100207211
    Abstract: A semiconductor device includes: a fin-type semiconductor region (13) formed on a substrate (11); a gate insulating film (14) formed so as to cover an upper surface and both side surfaces of a predetermined portion of the fin-type semiconductor region (13); a gate electrode (15) formed on the gate insulating film (14); and an impurity region (17) formed on both sides of the gate electrode (15) in the fin-type semiconductor region (13). An impurity blocking portion (15a) for blocking the introduction of impurities is provided adjacent both sides of the gate electrode (15) over an upper surface of the fin-type semiconductor region (13).
    Type: Application
    Filed: April 30, 2009
    Publication date: August 19, 2010
    Applicant: PANASONIC CORPORATION
    Inventors: Yuichiro Sasaki, Katsumi Okashita, Keiichi Nakamoto, Bunji Mizuno
  • Patent number: 7759254
    Abstract: A method of forming an impurity-introduced layer is disclosed. The method includes at least a step of forming a resist pattern on a principal face of a solid substrate such as a silicon substrate (S27); a step of introducing impurity into the solid substrate through plasma-doping in ion mode (S23), a step of removing a resist (S28), a step of cleaning metal contamination and particles attached to a surface of the solid substrate (S25a); a step of anneal (S26). The step of removing a resist (S28) irradiates the resist with oxygen-plasma or brings mixed solution of sulfuric acid and hydrogen peroxide water, or mixed solution of NH4OH, H2O2 and H2O into contact with the resist. The step of cleaning (S25a) brings mixed solution of sulfuric acid and hydrogen peroxide water, or mixed solution of NH4OH, H2O2 and H2O into contact with the principal face of the solid substrate.
    Type: Grant
    Filed: August 25, 2004
    Date of Patent: July 20, 2010
    Assignee: Panasonic Corporation
    Inventors: Yuichiro Sasaki, Katsumi Okashita, Bunji Mizuno, Hiroyuki Ito, Cheng-Guo Jin, Hideki Tamura, Ichiro Nakayama, Tomohiro Okumura, Satoshi Maeshima
  • Patent number: 7754503
    Abstract: A plasma of a gas containing an impurity is produced through a discharge in a vacuum chamber, and a plurality of substrates are successively doped with the impurity by using the plasma, wherein a plasma doping condition of a subject substrate is adjusted based on an accumulated discharge time until the subject substrate is placed in the vacuum chamber.
    Type: Grant
    Filed: January 9, 2008
    Date of Patent: July 13, 2010
    Assignee: Panasonic Corporation
    Inventors: Yuichiro Sasaki, Katsumi Okashita, Keiichi Nakamoto, Hiroyuki Ito, Bunji Mizuno
  • Publication number: 20100098837
    Abstract: It is intended to provide a plasma doping method and apparatus which are superior in the controllability of the concentration of an impurity that is introduced into a surface layer of a sample. A prescribed gas is introduced into a vacuum container 1 from a gas supply apparatus 2 while being exhausted by a turbomolecular pump 3 as an exhaust apparatus. The pressure in the vacuum container 1 is kept at a prescribed value by a pressure regulating valve 4. High-frequency electric power of 13.56 MHz is supplied from a high-frequency power source 5 to a coil 8 disposed close to a dielectric window 7 which is opposed to a sample electrode 6, whereby induction-coupled plasma is generated in the vacuum container 1. A high-frequency power source 10 for supplying high-frequency electric power to the sample electrode 6 is provided. Every time a prescribed number of samples have been processed, a dummy sample is subjected to plasma doping and then to heating.
    Type: Application
    Filed: December 28, 2009
    Publication date: April 22, 2010
    Applicant: Panasonic Corporation
    Inventors: Tomohiro OKUMURA, Yuichiro Sasaki, Katsumi Okashita, Hiroyuki Ito, Bunji Mizuno, Cheng-Guo Jin, Ichiro Nakayama
  • Publication number: 20100075489
    Abstract: A plasma of a gas containing an impurity is produced through a discharge in a vacuum chamber, and a plurality of substrates are successively doped with the impurity by using the plasma, wherein a plasma doping condition of a subject substrate is adjusted based on an accumulated discharge time until the subject substrate is placed in the vacuum chamber.
    Type: Application
    Filed: January 9, 2008
    Publication date: March 25, 2010
    Inventors: Yuichiro Sasaki, Katsumi Okashita, Keiichi Nakamoto, Hiroyuki Ito, Bunji Mizuno
  • Publication number: 20100015788
    Abstract: Plasma doping is performed by exposing a support substrate 11 made of a semiconductor to a plasma generated from a mixed gas of boron 51 which is an impurity and hydrogen 52 and helium 53 which are diluents so as to implant the boron 51 into the support substrate 11. Then, a preliminary heating step is performed by heating the support substrate 11 so that doses of the hydrogen 52 and the helium 53 are smaller than that of the boron 51 in the support substrate 11 by utilizing a difference between a thermal diffusion coefficient of the boron 51 in the support substrate 11 and those of the hydrogen 52 and the helium 53. Then, a laser heating step is performed for electrically activating the boron 51 implanted into the support substrate 11 using a laser.
    Type: Application
    Filed: September 5, 2008
    Publication date: January 21, 2010
    Inventors: Yuichiro Sasaki, Katsumi Okashita, Bunji Mizuno
  • Publication number: 20090317963
    Abstract: An amount of leakage of a substrate-cooling gas into a vacuum container is measured by using a flow-rate measuring device so that the flow rate of a diluting gas that is the same as the substrate-cooling gas is controlled by a control device or a plasma doping time is prolonged, in accordance with the amount of leakage.
    Type: Application
    Filed: August 28, 2008
    Publication date: December 24, 2009
    Inventors: Keiichi Nakamoto, Yuichiro Sasaki, Katsumi Okashita, Bunji Mizuno
  • Publication number: 20090289300
    Abstract: First and second gate insulating films are formed so as to cover at least the upper corner of first and second fin-shaped semiconductor regions. The radius of curvature r1? of the upper corner of the first fin-shaped semiconductor region located outside the first gate insulating film is greater than the radius of curvature r1 of the upper corner of the first fin-shaped semiconductor region located under the first gate insulating film and is less than or equal to 2×r1. The radius of curvature r2? of the upper corner of the second fin-shaped semiconductor region located outside the second gate insulating film is greater than the radius of curvature r2 of the upper corner of the second fin-shaped semiconductor region located under the second gate insulating film and is less than or equal to 2×r2.
    Type: Application
    Filed: July 30, 2009
    Publication date: November 26, 2009
    Inventors: Yuichiro SASAKI, Keiichi Nakamoto, Katsumi Okashita, Hisataka Kanada, Bunji Mizuno
  • Publication number: 20090266298
    Abstract: On an upper wall of a vacuum container opposing a sample electrode, a plasma-invasion prevention-and-electron beam introducing hole is installed which is communicated with an electron beam introducing tube, and is used for introducing an electron beam toward a substrate in the vacuum container, as well as for preventing invasion of plasma into the electron beam introducing tube. In this structure, supposing that the Debye length of the plasma is set to ?d and that a thickness of the sheath is set to Sd, the electron beam introducing hole has a diameter D satisfying a following equation: D?2?d+2Sd.
    Type: Application
    Filed: April 27, 2009
    Publication date: October 29, 2009
    Inventors: Katsumi Okashita, Yuichiro Sasaki, Bunji Mizuno
  • Patent number: 7601619
    Abstract: A method and an apparatus for plasma processing which can accurately monitor an ion current applied to the surface of a sample. Predetermined gas is exhausted via an exhaust port by a turbo-molecular pump while introducing the gas within the vacuum chamber from a gas supply device, and the pressure within the vacuum chamber is kept at a predetermined value by a pressure regulating valve. A high-frequency power supply for a plasma source supplies a high-frequency power to a coil provided near a dielectric window to generate inductively coupled plasma within the vacuum chamber. A high-frequency power supply for the sample electrode for supplying the high-frequency power to the sample electrode is provided. A matching circuit for the sample electrode and a high-frequency sensor are provided between the sample electrode high-frequency power supply and the sample electrode. An ion current applied to the surface of a sample can be accurately monitored buy using the high-frequency sensor and an arithmetic device.
    Type: Grant
    Filed: April 4, 2006
    Date of Patent: October 13, 2009
    Assignee: Panasonic Corporation
    Inventors: Tomohiro Okumura, Yuichiro Sasaki, Katsumi Okashita, Hiroyuki Ito, Bunji Mizuno, Cheng-Guo Jin, Ichiro Nakayama
  • Publication number: 20090233385
    Abstract: Before a plasma doping process is performed, there is generated a plasma of a gas containing an element belonging to the same group in the periodic table as the primary element of a silicon substrate 9, e.g., a monosilane gas, in a vacuum chamber 1. Thus, the inner wall of the vacuum chamber 1 is covered with a silicon-containing film. Then, a plasma doping process is performed on the silicon substrate 9.
    Type: Application
    Filed: October 4, 2007
    Publication date: September 17, 2009
    Applicant: PANASONIC CORPORATION
    Inventors: Tomohiro Okumura, Hisao Nagai, Yuichiro Sasaki, Katsumi Okashita, Hiroyuki Ito, Bunji Mizuno
  • Publication number: 20090233427
    Abstract: An impurity region is formed in a surface of a substrate by exposing the substrate to a plasma generated from a gas containing an impurity in a vacuum chamber. In this process, a plasma doping condition is set with respect to a dose of the impurity to be introduced into the substrate so that a first one of doses in a central portion and in a peripheral portion of the substrate is greater than a second one of the doses during an initial period of doping, with the second dose becoming greater than the first dose thereafter.
    Type: Application
    Filed: November 13, 2007
    Publication date: September 17, 2009
    Inventors: Yuichiro Sasaki, Katsumi Okashita, Hiroyuki Ito, Bunji Mizuno
  • Publication number: 20090233383
    Abstract: It is intended to provide a plasma doping method and apparatus which are superior in the controllability of the concentration of an impurity that is introduced into a surface layer of a sample. A prescribed gas is introduced into a vacuum container 1 from a gas supply apparatus 2 while being exhausted by a turbomolecular pump 3 as an exhaust apparatus. The pressure in the vacuum container 1 is kept at a prescribed value by a pressure regulating valve 4. High-frequency electric power of 13.56 MHz is supplied from a high-frequency power source 5 to a coil 8 disposed close to a dielectric window 7 which is opposed to a sample electrode 6, whereby induction-coupled plasma is generated in the vacuum container 1. A high-frequency power source 10 for supplying high-frequency electric power to the sample electrode 6 is provided. Every time a prescribed number of samples have been processed, a dummy sample is subjected to plasma doping and then to heating.
    Type: Application
    Filed: February 14, 2006
    Publication date: September 17, 2009
    Inventors: Tomohiro Okumura, Yuichiro Sasaki, Katsumi Okashita, Hiroyuki Ito, Bunji Mizuno, Cheng-Guo Jin, Ichiro Nakayama
  • Patent number: 7582492
    Abstract: The invention provides a method of doping impurities that includes a step of doping impurities in a solid base substance by using a plasma doping method, a step of forming a light antireflection layer that functions to reduce light reflection on the surface of the solid base substance, and a step of performing annealing by light radiation. According to the method, it is possible to reduce the reflectance of light radiated during annealing, to efficiently apply energy an impurity doped layer, to improve activation efficiency, to prevent diffusion, and to reduce sheet resistance of the impurity doped layer.
    Type: Grant
    Filed: May 19, 2005
    Date of Patent: September 1, 2009
    Assignee: Panasonic Corporation
    Inventors: Cheng-Guo Jin, Yuichiro Sasaki, Bunji Mizuno, Katsumi Okashita, Hiroyuki Ito, Tomohiro Okumura, Satoshi Maeshima, Ichiro Nakayama
  • Publication number: 20090186426
    Abstract: A plasma doping method and a plasma doping apparatus, having a superior in-plane uniformity of an amorphous layer formed on a sample surface, are provided. In the plasma doping method by which plasma is generated within a vacuum chamber, and impurity ions contained in the plasma are caused to collide with the surface of the sample so as to quality-change the surface of the sample into an amorphous state thereof, a plasma irradiation time is adjusted in order to improve an in-plane uniformity. If the plasma irradiation time becomes excessively short, then a fluctuation of the plasma is transferred to depths of an amorphous layer formed on a silicon substrate, so that the in-plane uniformity is deteriorated. On the other hand, if the irradiation time becomes excessively long, then an effect for sputtering the surface of the silicon substrate by using the plasma becomes dominant, then the in-plane uniformity is deteriorated.
    Type: Application
    Filed: March 28, 2006
    Publication date: July 23, 2009
    Inventors: Yuichiro Sasaki, Katsumi Okashita, Hiroyuki Ito, Bunji Mizuno
  • Publication number: 20090181526
    Abstract: An object of the invention is to provide a plasma doping method and a plasma doping apparatus in which uniformity of concentration of impurities introduced into a sample surface are excellent. The plasma doping apparatus of the invention introduces a predetermined mass flow of gas from a gas supply device (2) into a vacuum chamber (1) while discharging the gas through an exhaust port (11) by a turbo-molecular pump (3), which is an exhaust device in order to maintain the vacuum chamber (1) under a predetermined pressure by a pressure adjusting valve (4). A high-frequency power source (5) supplies high-frequency power of 13.56 MHz to a coil (8) disposed in the vicinity of a dielectric window (7) opposite a sample electrode (6) in order to generate an inductively coupled plasma in the vacuum chamber (1). A high-frequency power source (10) for supplying high-frequency power to the sample electrode (6) is provided.
    Type: Application
    Filed: March 30, 2006
    Publication date: July 16, 2009
    Inventors: Tomohiro Okumura, Yuichiro Sasaki, Katsumi Okashita, Bunji Mizuno, Hiroyuki Ito, Ichiro Nakayama, Cheng-Guo Jin