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).
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Patent number: 7820230Abstract: 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: GrantFiled: August 28, 2008Date of Patent: October 26, 2010Assignee: Panasonic CorporationInventors: Keiichi Nakamoto, Yuichiro Sasaki, Katsumi Okashita, Bunji Mizuno
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Publication number: 20100255615Abstract: 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: ApplicationFiled: October 2, 2008Publication date: October 7, 2010Inventors: Katsumi Okashita, Yuichiro Sasaki, Keiichi Nakamoto, Bunji Mizuno
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Patent number: 7800165Abstract: 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: GrantFiled: February 4, 2008Date of Patent: September 21, 2010Assignee: Panasonic CorporationInventors: Yuichiro Sasaki, Katsumi Okashita, Keiichi Nakamoto, Hiroyuki Ito, Bunji Mizuno
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Patent number: 7790586Abstract: 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: GrantFiled: November 13, 2007Date of Patent: September 7, 2010Assignee: Panasonic CorporationInventors: Yuichiro Sasaki, Katsumi Okashita, Hiroyuki Ito, Bunji Mizuno
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Publication number: 20100207211Abstract: 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: ApplicationFiled: April 30, 2009Publication date: August 19, 2010Applicant: PANASONIC CORPORATIONInventors: Yuichiro Sasaki, Katsumi Okashita, Keiichi Nakamoto, Bunji Mizuno
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Patent number: 7759254Abstract: 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: GrantFiled: August 25, 2004Date of Patent: July 20, 2010Assignee: Panasonic CorporationInventors: Yuichiro Sasaki, Katsumi Okashita, Bunji Mizuno, Hiroyuki Ito, Cheng-Guo Jin, Hideki Tamura, Ichiro Nakayama, Tomohiro Okumura, Satoshi Maeshima
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Patent number: 7754503Abstract: 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: GrantFiled: January 9, 2008Date of Patent: July 13, 2010Assignee: Panasonic CorporationInventors: Yuichiro Sasaki, Katsumi Okashita, Keiichi Nakamoto, Hiroyuki Ito, Bunji Mizuno
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Publication number: 20100098837Abstract: 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: ApplicationFiled: December 28, 2009Publication date: April 22, 2010Applicant: Panasonic CorporationInventors: Tomohiro OKUMURA, Yuichiro Sasaki, Katsumi Okashita, Hiroyuki Ito, Bunji Mizuno, Cheng-Guo Jin, Ichiro Nakayama
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Publication number: 20100075489Abstract: 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: ApplicationFiled: January 9, 2008Publication date: March 25, 2010Inventors: Yuichiro Sasaki, Katsumi Okashita, Keiichi Nakamoto, Hiroyuki Ito, Bunji Mizuno
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Publication number: 20100015788Abstract: 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: ApplicationFiled: September 5, 2008Publication date: January 21, 2010Inventors: Yuichiro Sasaki, Katsumi Okashita, Bunji Mizuno
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Publication number: 20090317963Abstract: 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: ApplicationFiled: August 28, 2008Publication date: December 24, 2009Inventors: Keiichi Nakamoto, Yuichiro Sasaki, Katsumi Okashita, Bunji Mizuno
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Publication number: 20090289300Abstract: 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: ApplicationFiled: July 30, 2009Publication date: November 26, 2009Inventors: Yuichiro SASAKI, Keiichi Nakamoto, Katsumi Okashita, Hisataka Kanada, Bunji Mizuno
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Publication number: 20090266298Abstract: 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: ApplicationFiled: April 27, 2009Publication date: October 29, 2009Inventors: Katsumi Okashita, Yuichiro Sasaki, Bunji Mizuno
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Patent number: 7601619Abstract: 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: GrantFiled: April 4, 2006Date of Patent: October 13, 2009Assignee: Panasonic CorporationInventors: Tomohiro Okumura, Yuichiro Sasaki, Katsumi Okashita, Hiroyuki Ito, Bunji Mizuno, Cheng-Guo Jin, Ichiro Nakayama
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Publication number: 20090233385Abstract: 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: ApplicationFiled: October 4, 2007Publication date: September 17, 2009Applicant: PANASONIC CORPORATIONInventors: Tomohiro Okumura, Hisao Nagai, Yuichiro Sasaki, Katsumi Okashita, Hiroyuki Ito, Bunji Mizuno
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Publication number: 20090233427Abstract: 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: ApplicationFiled: November 13, 2007Publication date: September 17, 2009Inventors: Yuichiro Sasaki, Katsumi Okashita, Hiroyuki Ito, Bunji Mizuno
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Publication number: 20090233383Abstract: 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: ApplicationFiled: February 14, 2006Publication date: September 17, 2009Inventors: Tomohiro Okumura, Yuichiro Sasaki, Katsumi Okashita, Hiroyuki Ito, Bunji Mizuno, Cheng-Guo Jin, Ichiro Nakayama
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Patent number: 7582492Abstract: 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: GrantFiled: May 19, 2005Date of Patent: September 1, 2009Assignee: Panasonic CorporationInventors: Cheng-Guo Jin, Yuichiro Sasaki, Bunji Mizuno, Katsumi Okashita, Hiroyuki Ito, Tomohiro Okumura, Satoshi Maeshima, Ichiro Nakayama
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Publication number: 20090186426Abstract: 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: ApplicationFiled: March 28, 2006Publication date: July 23, 2009Inventors: Yuichiro Sasaki, Katsumi Okashita, Hiroyuki Ito, Bunji Mizuno
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Publication number: 20090181526Abstract: 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: ApplicationFiled: March 30, 2006Publication date: July 16, 2009Inventors: Tomohiro Okumura, Yuichiro Sasaki, Katsumi Okashita, Bunji Mizuno, Hiroyuki Ito, Ichiro Nakayama, Cheng-Guo Jin