Patents by Inventor Akira Asai

Akira Asai 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).

  • Publication number: 20060129337
    Abstract: During an incompressible fluid movement, three consecutive times during the movement of the fluid are called first, second, and third times in time order, calculation is performed with two different types of lattices for the first and third times and for the second time. Momentum and mass density at the first time are temporally developed to the third time in accordance with a conservation law by using an upwind velocity field. A pressure at the second time is determined so that a velocity field derived from momenta at the third time satisfies an incompressibility condition, and the field at the third time is corrected by adding a change in momentum caused by a pressure term using the determined pressure. This prevents pressure vibration and avoids the complexity of advective term calculation.
    Type: Application
    Filed: December 15, 2005
    Publication date: June 15, 2006
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: KOTA NAKANO, AKIRA ASAI
  • Patent number: 7049198
    Abstract: An S1-yGey layer (where 0<y<1), an Si layer containing C, a gate insulating film and a gate electrode are formed in this order on a semiconductor substrate. An Si/SiGe heterojunction is formed between the Si and Si1-yGey layers. Since C is contained in the Si layer, movement, diffusion and segregation of Ge atoms in the S1-yGey layer can be suppressed. As a result, the Si/Si1-yGey interface can have its structural disorder eased and can be kept definite and planar. Thus, the mobility of carriers moving along the interface in the channel can be increased. That is to say, the thermal budget of the semiconductor device during annealing can be improved. Also, by grading the concentration profile of C, the diffusion of C into the gate insulating film can be suppressed and decline in reliability can be prevented.
    Type: Grant
    Filed: March 4, 2003
    Date of Patent: May 23, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Koichiro Yuki, Tohru Saitoh, Minoru Kubo, Kiyoshi Ohnaka, Akira Asai, Koji Katayama
  • Patent number: 7049681
    Abstract: A Si1-xGex layer 111b functioning as the base composed of an i-Si1-xGex layer and a p+ Si1-xGex layer is formed on a collector layer 102, and a Si cap layer 111a as the emitter is formed on the p+ Si1-xGex layer. An emitter lead electrode 129, which is composed of an n? polysilicon layer 129b containing phosphorus in a concentration equal to or lower than the solid-solubility limit for single-crystal silicon and a n+ polysilicon layer 129a containing phosphorus in a high concentration, is formed on the Si cap layer 111a in a base opening 118. The impurity concentration distribution in the base layer is properly maintained by suppressing the Si cap layer 111a from being doped with phosphorus (P) in an excessively high concentration. The upper portion of the Si cap layer 111a may contain a p-type impurity. The p-type impurity concentration distribution in the base layer of an NPN bipolar transistor is thus properly maintained.
    Type: Grant
    Filed: October 26, 2004
    Date of Patent: May 23, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Teruhito Ohnishi, Akira Asai
  • Publication number: 20060086988
    Abstract: A semiconductor integrated circuit fabrication method according to this invention includes: a step of forming a pair of first device forming regions and a pair of second device forming regions in a surface layer portion of a semiconductor substrate by surrounding each of the regions by device isolation; a step of forming a first oxide film covering the surface of the semiconductor substrate after the preceding step; a step of removing an intended portion of the first oxide film to expose the pair of second device forming regions; a step of forming a pair of heterojunction structures, by selective epitaxial growth, on the pair of second device forming regions thus exposed; a step of forming a second oxide film covering the surface of the substrate after the preceding step; and a step of forming a pair of gate electrodes above each of the pair of first device forming regions and the pair of second device forming regions, whereby a normal complementary MOS transistor and a heterojunction complementary MOS transi
    Type: Application
    Filed: December 6, 2005
    Publication date: April 27, 2006
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventors: Haruyuki Sorada, Akira Asai, Takeshi Takagi, Akira Inoue, Yoshio Kawashima
  • Publication number: 20060054944
    Abstract: The present invention provides a semiconductor device comprising: a semiconductor layer (3); a gate electrode (11) formed on the semiconductor layer (3) via a gate insulation film (10); and a first insulation film (13) formed at one or more of sidewalls of the semiconductor layer (3), the gate insulation film (10) and the gate electrode (11); wherein the first insulation film (13) overlies a part of the gate insulation film (10) surface. According to the semiconductor device, leakage current at the isolation edge can be suppressed and thus reliability can be improved.
    Type: Application
    Filed: October 28, 2005
    Publication date: March 16, 2006
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Haruyuki Sorada, Takeshi Takagi, Akira Asai, Akira Inoue
  • Patent number: 6987065
    Abstract: The present invention provides a semiconductor device comprising: a semiconductor layer (3); a gate electrode (11) formed on the semiconductor layer (3) via a gate insulation film (10); and a first insulation film (13) formed at one or more of sidewalls of the semiconductor layer (3), the gate insulation film (10) and the gate electrode (11); wherein the first insulation film (13) overlies a part of the gate insulation film (10) surface. According to the semiconductor device, leakage current at the isolation edge can be suppressed and thus reliability can be improved.
    Type: Grant
    Filed: July 15, 2004
    Date of Patent: January 17, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Haruyuki Sorada, Takeshi Takagi, Akira Asai, Akira Inoue
  • Patent number: 6987072
    Abstract: A method for fabricating a semiconductor crystal that has a first step for forming a semiconductor crystal layer (202) that contains carbon atoms and at least one kind of Group IV element other than carbon on a substrate (201), a second step for adding an impurity that is capable of reacting with oxygen to the semiconductor crystal layer (202), and a third step for removing the carbon atoms contained in the semiconductor crystal layer (202) by reacting the carbon with the impurity. This method makes it possible to fabricate a semiconductor crystal substrate in which the concentration of interstitial carbon atoms is satisfactorily reduced, thus resulting in excellent electrical properties when the substrate is applied to a semiconductor device.
    Type: Grant
    Filed: December 13, 2004
    Date of Patent: January 17, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yoshihiko Kanzawa, Teruhito Ohnishi, Ken Idota, Tohru Saitoh, Akira Asai
  • Publication number: 20050209898
    Abstract: The solution of a constrained optimization problem is easily solved by linearly approximating a point of interest to a first hypersurface given as a constraint and finding the extreme value of the objective function by moving a point r along a curved line having second-order osculation with the geodetic line of a hypersurface S(r)=c and passing through the point r.
    Type: Application
    Filed: March 9, 2005
    Publication date: September 22, 2005
    Inventors: Akira Asai, Shigeki Matsutani, Katsuhiko Shinjo, Masanori Kuroda, Daichi Tsutsumi
  • Patent number: 6939772
    Abstract: A SiGe spacer layer 151, a graded SiGe base layer 152 including boron, and an Si-cap layer 153 are sequentially grown through epitaxial growth over a collector layer 102 on an Si substrate. A second deposited oxide film 112 having a base opening portion 118 and a P+ polysilicon layer 115 that will be made into an emitter connecting electrode filling the base opening portion are formed on the Si-cap layer 153, and an emitter diffusion layer 153a is formed by diffusing phosphorus into the Si-cap layer 153. When the Si-cap layer 153 is grown, by allowing the Si-cap layer 153 to include boron only at the upper part thereof by in-situ doping, the width of a depletion layer 154 is narrowed and a recombination current is reduced, thereby making it possible to improve the linearity of the current characteristics.
    Type: Grant
    Filed: July 2, 2004
    Date of Patent: September 6, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Akira Asai, Teruhito Ohnishi, Takeshi Takagi
  • Patent number: 6926392
    Abstract: A liquid ejection head includes a liquid path; an ejection outlet forming member which constitutes a part of a wall of the liquid and which forms an ejection outlet for ejecting a droplet of liquid; a heat generating element, provided at a position opposing to the ejection outlet of the wall of the liquid flow path, for generating a bubble in the liquid by application of heat to the liquid; a restrictor portion, provided at a recessed portion of the ejection outlet, wherein the recessed portion is recessed from a plane in which the ejection outlet is formed, wherein the liquid forms a meniscus and is retained in the ejection outlet such that the restrictor portion is within the liquid, wherein an area So of an opening of the restrictor portion and a surface Sh of the heat generating element satisfy So?Sh. According to this invention, a central portion of the meniscus opposed to the fine opening at the ejection outlet bulges, and the liquid is ejected in this state.
    Type: Grant
    Filed: July 17, 2003
    Date of Patent: August 9, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventors: Toshiaki Sasaki, Keiichi Murai, Yasuyuki Tamura, Sadayuki Sugama, Akira Asai, Tsutomu Kawai, Masayoshi Tachihara
  • Patent number: 6927118
    Abstract: The present invention discloses a process of fabricating a semiconductor device comprising the steps of: forming a collector layer of a first conductivity type at a portion of a surface of a semiconductor substrate; forming a collector opening portion in a first insulating layer formed on the semiconductor substrate; epitaxially growing, on the semiconductor substrate of the collector opening portion, a semiconductor layer including a layer of a second conductivity type constituting a base layer; sequentially layering, on the semiconductor substrate, an etching stopper layer against dry etching and a masking layer against wet etching; exposing a part of the etching stopper layer by removing a part of the masking layer by means of dry etching; and by subjecting the exposed etching stopper layer to a wet etching treatment using the remaining masking layer as a mask, forming a base junction opening portion through the etching stopper layer and the masking layer.
    Type: Grant
    Filed: October 29, 2003
    Date of Patent: August 9, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Ken Idota, Teruhito Ohnishi, Akira Asai
  • Patent number: 6917075
    Abstract: A semiconductor device and a method of fabricating the same according to this invention are such that: a gate insulator is formed over a predetermined region of a semiconductor substrate; a gate electrode is formed on the gate insulator; source and drain regions respectively formed in portions of the predetermined region that are situated on both sides of the gate electrode in plan view; a body region formed by a region of the predetermined region exclusive of the source and drain regions; and a contact electrically interconnecting the gate electrode and the body region, wherein a portion of the contact which is connected to the gate electrode is formed to intersect the gate electrode in plan view.
    Type: Grant
    Filed: January 7, 2004
    Date of Patent: July 12, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Akira Inoue, Akira Asai, Teruhito Ohnishi, Haruyuki Sorada, Yoshihiro Hara, Takeshi Takagi
  • Patent number: 6893934
    Abstract: A Si1-xGex layer 111b functioning as the base composed of an i—Si1-xGex layer and a p+ Si1-xGex layer is formed on a collector layer 102, and a Si cap layer 111a as the emitter is formed on the p+ Si1-xGex layer. An emitter lead electrode 129, which is composed of an n? polysilicon layer 129b containing phosphorus in a concentration equal to or lower than the solid-solubility limit for single-crystal silicon and a n+ polysilicon layer 129a containing phosphorus in a high concentration, is formed on the Si cap layer 111a in a base opening 118. The impurity concentration distribution in the base layer is properly maintained by suppressing the Si cap layer 111a from being doped with phosphorus (P) in an excessively high concentration. The upper portion of the Si cap layer 111a may contain a p-type impurity. The p-type impurity concentration distribution in the base layer of an NPN bipolar transistor is thus properly maintained.
    Type: Grant
    Filed: June 26, 2003
    Date of Patent: May 17, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Teruhit Ohnishi, Akira Asai
  • Publication number: 20050092230
    Abstract: A method for fabricating a semiconductor crystal that has a first step for forming a semiconductor crystal layer (202) that contains carbon atoms and at least one kind of Group IV element other than carbon on a substrate (201), a second step for adding an impurity that is capable of reacting with oxygen to the semiconductor crystal layer (202), and a third step for removing the carbon atoms contained in the semiconductor crystal layer (202) by reacting the carbon with the impurity. This method makes it possible to fabricate a semiconductor crystal substrate in which the concentration of interstitial carbon atoms is satisfactorily reduced, thus resulting in excellent electrical properties when the substrate is applied to a semiconductor device.
    Type: Application
    Filed: December 13, 2004
    Publication date: May 5, 2005
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventors: Yoshihiko Kanzawa, Teruhito Ohnishi, Ken Idota, Tohru Saitoh, Akira Asai
  • Publication number: 20050087764
    Abstract: A MISFET according to this invention includes: a substrate having a semiconductor layer; an active region formed in the semiconductor layer; a gate insulator formed on the active region; a gate formed on the gate insulator; and a source region and a drain region, wherein: the active region is formed, in plan view, to have a body portion and a projecting portion projecting from a periphery of the body portion; the gate is formed, in plan view, to intersect the body portion of the active region, cover a pair of connecting portions connecting a periphery of the projecting portion to the periphery of the body portion and allow a part of the projecting portion to project from a periphery of the gate; and the source region and the drain region are formed in regions of the body portion of the active region which are situated on opposite sides of the gate in plan view, respectively.
    Type: Application
    Filed: November 2, 2004
    Publication date: April 28, 2005
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventors: Akira Inoue, Takeshi Takagi, Akira Asai, Haruyuki Sorada
  • Publication number: 20050087803
    Abstract: On an Si substrate 1, a buffer layer 2, a SiGe layer 3, and an Si cap layer 4 are formed. A mask is formed on the substrate, and then the substrate is patterned. In this manner, a trench 7a is formed so as to reach the Si substrate 1 and have the side faces of the SiGe layer 3 exposed. Then, the surface of the trench 7a is subjected to heat treatment for one hour at 750° C. so that Ge contained in a surface portion of the SiGe layer 3 is evaporated. Thus, a Ge evaporated portion 8 having a lower Ge content than that of other part of the SiGe layer 3 is formed in part of the SiGe layer 3 exposed at part of the trench 7a. Thereafter, the walls of the trench 7a are oxidized.
    Type: Application
    Filed: November 24, 2004
    Publication date: April 28, 2005
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yoshihiro Hara, Akira Asai, Gaku Sugahara, Haruyuki Sorada, Teruhito Ohnishi
  • Publication number: 20050082571
    Abstract: A Si1-xGex layer 111b functioning as the base composed of an i-Si1-xGex layer and a p+ Si1-xGex layer is formed on a collector layer 102, and a Si cap layer 111a as the emitter is formed on the p+ Si1-xGex layer. An emitter lead electrode 129, which is composed of an n? polysilicon layer 129b containing phosphorus in a concentration equal to or lower than the solid-solubility limit for single-crystal silicon and a n+ polysilicon layer 129a containing phosphorus in a high concentration, is formed on the Si cap layer 111a in a base opening 118. The impurity concentration distribution in the base layer is properly maintained by suppressing the Si cap layer 111a from being doped with phosphorus (P) in an excessively high concentration. The upper portion of the Si cap layer 111a may contain a p-type impurity. The p-type impurity concentration distribution in the base layer of an NPN bipolar transistor is thus properly maintained.
    Type: Application
    Filed: October 26, 2004
    Publication date: April 21, 2005
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventors: Teruhito Ohnishi, Akira Asai
  • Publication number: 20050073556
    Abstract: A liquid ejection head includes a liquid path; an ejection outlet forming member which constitutes a part of a wall of the liquid and which forms an ejection outlet for ejecting a droplet of liquid; a heat generating element, provided at a position opposing to the ejection outlet of the wall of the liquid flow path, for generating a bubble in the liquid by application of heat to the liquid; a restrictor portion, provided at a recessed portion of the ejection outlet, wherein the recessed portion is recessed from a plane in which the ejection outlet is formed, wherein the liquid forms a meniscus and is retained in the ejection outlet such that the restrictor portion is within the liquid, wherein an area So of an opening of the restrictor portion and a surface Sh of the heat generating element satisfy So?Sh. According to this invention, a central portion of the meniscus opposed to the fine opening at the ejection outlet bulges, and the liquid is ejected in this state.
    Type: Application
    Filed: July 17, 2003
    Publication date: April 7, 2005
    Applicant: Canon Kabushiki Kaisha
    Inventors: Toshiaki Sasaki, Keiichi Murai, Yasuyuki Tamura, Sadayuki Sugama, Akira Asai, Tsutomu Kawai, Masayoshi Tachihara
  • Patent number: 6869971
    Abstract: UCS 1025 derivatives having antitumor activity or antibacterial activity which are represented by formula (I): wherein R1 represents hydrogen, lower alkyl, etc.; R2 represents hydrogen, or is combined with R3 to represent a bond, etc., or is combined with R4 to represent —O(C?O)—, etc.; R3 represents hydrogen, etc., or is combined with R2 to represent a bond, etc.; R4 represents hydrogen, etc., or is combined with R2 to represent —(C?O)O—, etc.; R5 represents hydrogen or is combined with R6 to represent a bond; R6 represents hydrogen, etc., or is combined with R5 to represent a bond; R7 represents hydrogen or is combined with R8 to represent ?O; R8 represents hydroxy or is combined with R7 to represent ?O; ---- represents a single bond or a double bond, and a represents a single bond (two carbon atoms to which a is bound are combined to form a single bond) or an oxygen atom, or pharmaceutically acceptable salts thereof.
    Type: Grant
    Filed: October 19, 2000
    Date of Patent: March 22, 2005
    Assignee: Kyowa Hakko Kogyo Co., Ltd.
    Inventors: Tsutomu Akama, Akira Asai, Tsutomu Agatsuma, Shinji Nara, Yoshinori Yamashita, Tamio Mizukami, Shun-ichi Ikeda, Yutaka Saitoh, Yutaka Kanda
  • Patent number: 6867107
    Abstract: A variable capacitance device comprising, in a semiconductor layer formed on a substrate via an buried oxide film: an n? region 132 formed in the shape of a ring and containing an n-type dopant; an anode 133 adjoined to the outer periphery of the n? region 132, the anode 133 being formed in the shape of a ring and containing a p-type dopant; and a cathode 131 adjoined to the inner periphery of the n? region 132, the third region containing an n-type dopant, wherein the dopant concentration in the n? region 132 is lower than that in each of the anode 133 and the cathode 131.
    Type: Grant
    Filed: June 9, 2003
    Date of Patent: March 15, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Akira Asai, Teruhito Ohnishi