Patents by Inventor Makoto Ogasawara

Makoto Ogasawara 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: 20020093060
    Abstract: A width of a circuit device isolation region and a width of a device region formed on a semiconductor substrate are determined in such a manner as to satisfy a condition which prevents the occurrence of dislocation due to thermal oxidation for forming the isolation region. A semiconductor device can be fabrication which includes a semiconductor substrate, a plurality of circuit regions formed on a device formation region in the semiconductor substrate and having a width of 0.1 to 125 &mgr;m and device isolation regions so formed on the semiconductor substrate as to isolate a plurality of circuit regions from one another and having a width of 0.05 to 2.5 &mgr;m, and wherein a ratio of the width of the device isolation region to the width of a plurality of circuit regions adjacent to the device isolation region is from 2 to 50.
    Type: Application
    Filed: June 29, 2001
    Publication date: July 18, 2002
    Inventors: Hideo Miura, Makoto Ogasawara, Hiroo Masuda, Jun Murata, Noriaki Okamoto, Yasunobu Tanizaki, Eiji Wakimoto, Shinji Sakata
  • Publication number: 20020017669
    Abstract: Herein disclosed is a semiconductor integrated circuit device fabricating process for forming MISFETs over the principal surface in those active regions of a substrate, which are surrounded by inactive regions formed of an element separating insulating film and channel stopper regions, comprising: the step of for forming a first mask by a non-oxidizable mask and an etching mask sequentially over the principal surface of the active regions of the substrate; the step of forming a second mask on and in self-alignment with the side walls of the first mask by a non-oxidizable mask thinner than the non-oxidizable mask of the first mask and an etching mask respectively; the step of etching the principal surface of the inactive regions of the substrate by using the first mask and the second mask; the step of forming the element separating insulating film over the principal surface of the inactive regions of the substrate by an oxidization using the first mask and the second mask; and the step of forming the channel s
    Type: Application
    Filed: July 9, 2001
    Publication date: February 14, 2002
    Inventors: Jun Sugiura, Osamu Tsuchiya, Makoto Ogasawara, Fumio Ootsuka, Kazuyoshi Torii, Isamu Asano, Nobuo Owada, Mitsuaki Horiuchi, Tsuyoshi Tamaru, Hideo Aoki, Nobuhiro Otsuka, Seiichirou Shirai, Masakazu Sagawa, Yoshihiro Ikeda, Masatoshi Tsuneoka, Toru Kaga, Tomotsugu Shimmyo, Hidetsugu Ogishi, Osamu Kasahara, Hiromichi Enami, Atsushi Wakahara, Hiroyuki Akimori, Sinichi Suzuki, Keisuke Funatsu, Yoshinao Kawasaki, Tunehiko Tubone, Takayoshi Kogano, Ken Tsugane
  • Patent number: 6342412
    Abstract: Herein disclosed is a semiconductor integrated circuit device fabricating process for forming MISFETs over the principal surface in those active regions of a substrate, which are surrounded by inactive regions formed of an element separating insulating film and channel stopper regions, comprising: the step of for forming a first mask by a non-oxidizable mask and an etching mask sequentially over the principal surface of the active regions of the substrate; the step of forming a second mask on and in self-alignment with the side walls of the first mask by a non-oxidizable mask thinner than the non-oxidizable mask of the first mask and an etching mask respectively; the step of etching the principal surface of the inactive regions of the substrate by using the first mask and the second mask; the step of forming the element separating insulating film over the principal surface of the inactive regions of the substrate by an oxidization using the first mask and the second mask; and the step of forming the channel s
    Type: Grant
    Filed: December 14, 1999
    Date of Patent: January 29, 2002
    Assignees: Hitachi, Ltd., Hitachi VLSI Engineering Corp.
    Inventors: Jun Sugiura, Osamu Tsuchiya, Makoto Ogasawara, Fumio Ootsuka, Kazuyoshi Torii, Isamu Asano, Nobuo Owada, Mitsuaki Horiuchi, Tsuyoshi Tamaru, Hideo Aoki, Nobuhiro Otsuka, Seiichirou Shirai, Masakazu Sagawa, Yoshihiro Ikeda, Masatoshi Tsuneoka, Toru Kaga, Tomotsugu Shimmyo, Hidetsugu Ogishi, Osamu Kasahara, Hiromichi Enami, Atsushi Wakahara, Hiroyuki Akimori, Sinichi Suzuki, Keisuke Funatsu, Yoshinao Kawasaki, Tunehiko Tubone, Takayoshi Kogano, Ken Tsugane
  • Publication number: 20020000595
    Abstract: A field oxide film 3 in a region where relief cells are formed is made wider than the field oxide film 3 in a region where normal memory cells are formed thereby to make a field relaxation layer 8r of the relief cells deeper than the field relaxation layer 8 of the normal cells, and the depletion layer of the sources and drains (n-type semiconductor regions) of the relief cells is widened to weaken the junction field.
    Type: Application
    Filed: August 7, 2001
    Publication date: January 3, 2002
    Inventors: Kiyonori Ohyu, Makoto Ohkura, Aritoshi Sugimoto, Yoshitaka Tadaki, Makoto Ogasawara, Masashi Horiguchi, Norio Hasegawa, Shinichi Fukada
  • Patent number: 6310384
    Abstract: A width of a circuit device isolation region and a width of a device region formed on a semiconductor substrate are determined in such a manner as to satisfy a condition which prevents the occurrence of dislocation due to thermal oxidation for forming the isolation region. In accordance with the manufacturing scheme, a semiconductor device produced includes a semiconductor substrate, a plurality of circuit regions formed on a device formation region in the semiconductor substrate and having a width of 0.1 to 125 &mgr;m and device isolation regions so formed on the semiconductor substrate as to isolate a plurality of circuit regions from one another and having a width of 0.01 to 2.5 &mgr;m. In such a schemed device, a ratio of the width of the device region to the width of the device isolation region is from 2 to 50.
    Type: Grant
    Filed: April 17, 1997
    Date of Patent: October 30, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Hideo Miura, Makoto Ogasawara, Hiroo Masuda, Jun Murata, Noriaki Okamoto
  • Patent number: 6291847
    Abstract: A field oxide film 3 in a region where relief cells are formed is made wider than the field oxide film 3 in a region where normal memory cells are formed thereby to make a field relaxation layer 8r of the relief cells deeper than the field relaxation layer 8 of the normal cells, and the depletion layer of the sources and drains (n-type semiconductor regions) of the relief cells is widened to weaken the junction field.
    Type: Grant
    Filed: September 24, 1998
    Date of Patent: September 18, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Kiyonori Ohyu, Makoto Ohkura, Aritoshi Sugimoto, Yoshitaka Tadaki, Makoto Ogasawara, Masashi Horiguchi, Norio Hasegawa, Shinichi Fukada
  • Patent number: 6169324
    Abstract: Herein disclosed is a semiconductor integrated circuit device fabricating process for forming MISFETs over the principal surface in those active regions of a substrate, which are surrounded by inactive regions formed of an element separating insulating film and channel stopper regions, comprising: the step of for forming a first mask by a non-oxidizable mask and an etching mask sequentially over the principal surface of the active regions of the substrate; the step of forming a second mask on and in self-alignment with the side walls of the first mask by a non-oxidizable mask thinner than the non-oxidizable mask of the first mask and an etching mask respectively; the step of etching the principal surface of the inactive regions of the substrate by using the first mask and the second mask; the step of forming the element separating insulating film over the principal surface of the inactive regions of the substrate by an oxidization using the first mask and the second mask; and the step of forming the channel s
    Type: Grant
    Filed: October 6, 1999
    Date of Patent: January 2, 2001
    Assignees: Hitachi, Ltd., Hitachi VLSI Engineering Corp.
    Inventors: Jun Sugiura, Osamu Tsuchiya, Makoto Ogasawara, Fumio Ootsuka, Kazuyoshi Torii, Isamu Asano, Nobuo Owada, Mitsuaki Horiuchi, Tsuyoshi Tamaru, Hideo Aoki, Nobuhiro Otsuka, Seiichirou Shirai, Masakazu Sagawa, Yoshihiro Ikeda, Masatoshi Tsuneoka, Toru Kaga, Tomotsugu Shimmyo, Hidetsugu Ogishi, Osamu Kasahara, Hiromichi Enami, Atsushi Wakahara, Hiroyuki Akimori, Sinichi Suzuki, Keisuke Funatsu, Yoshinao Kawasaki, Tunehiko Tubone, Takayoshi Kogano, Ken Tsugane
  • Patent number: 6127255
    Abstract: Herein disclosed is a semiconductor integrated circuit device fabricating process for forming MISFETs over the principal surface in active regions of a substrate, which are surrounded by inactive regions formed of an element separating insulating film and channel stopper regions. The disclosed process includes forming insulating films over wiring lines including uppermost wiring lines, the uppermost wiring lines having gaps between adjacent uppermost wiring lines. The insulating films include forming a silicon oxide film over the wiring lines and in the gaps between adjacent uppermost wiring lines, and forming a silicon nitride film over the silicon oxide film, the silicon nitride film being formed by plasma chemical vapor deposition. The silicon oxide film is formed to have a thickness of at least one-half of the gap between adjacent uppermost wiring lines, with the silicon nitride film being thicker than the silicon oxide film.
    Type: Grant
    Filed: October 3, 1997
    Date of Patent: October 3, 2000
    Assignees: Hitachi, Ltd., Hitachi VLSI Engineering Corp.
    Inventors: Jun Sugiura, Osamu Tsuchiya, Makoto Ogasawara, Fumio Ootsuka, Kazuyoshi Torii, Isamu Asano, Nobuo Owada, Mitsuaki Horiuchi, Tsuyoshi Tamaru, Hideo Aoki, Nobuhiro Otsuka, Seiichirou Shirai, Masakazu Sagawa, Yoshihiro Ikeda, Masatoshi Tsuneoka, Toru Kaga, Tomotsugu Shimmyo, Hidetsugu Ogishi, Osamu Kasahara, Hiromichi Enami, Atsushi Wakahara, Hiroyuki Akimori, Sinichi Suzuki, Keisuke Funatsu, Yoshinao Kawasaki, Tunehiko Tubone, Takayoshi Kogano, Ken Tsugane
  • Patent number: 5889312
    Abstract: A semiconductor device includes a thermal oxide film for isolation, a semiconductor region that becomes an element forming region with the circumference thereof surrounded by the oxide film and diffused resistance layers in the semiconductor region and provides a structure for controlling resistance value variation of diffused resistors originated in a stress generated at time of forming the oxide film for isolation. A distance between an end portion on a longer side closest to a thermal oxide film of the diffused layer and an end of the thermal oxide film is apart from each other by a predetermined value determined by stress distribution in the semiconductor region or by at least 4 .mu.
    Type: Grant
    Filed: July 10, 1997
    Date of Patent: March 30, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Hideo Miura, Yasunobu Tanizaki, Eiji Wakimoto, Shinji Sakata, Makoto Ogasawara, Hiroo Masuda, Jun Murata, Noriaki Okamoto
  • Patent number: 5874877
    Abstract: A circuit breaker with a completely electromagnetic type overcurrent tripping device has a flexibility for changes in the production schedule of the overcurrent tripping device. An overcurrent tripping device for each pole is integrally housed in a common unit case, which is then inserted into a case of the circuit breaker. In this case, a yoke of the overcurrent tripping device is combined with an oil dash pot inserted into a coil, and the combined parts are pressed and fixed in the unit case without soldering. Thus, the coil, which is changed depending on the rated current, and the yoke and oil dash pot which are common products, can be separately stored prior to assembly, thereby enabling flexible responses to changes in the production schedule. In addition, the yoke and the oil dash pot need not be soldered and are fixed individually to the unit case, thereby reducing the number of assembly operations.
    Type: Grant
    Filed: July 29, 1997
    Date of Patent: February 23, 1999
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Yoshiaki Kawashima, Kazuhiko Satoh, Tadahisa Aoki, Makoto Ogasawara
  • Patent number: 5811316
    Abstract: Herein disclosed is a semiconductor integrated circuit device fabricating process for forming MISFETs over the principal surface in those active regions of a substrate, which are surrounded by inactive regions formed of an element separating insulating film and channel stopper regions, comprising: the step of for forming a first mask by a non-oxidizable mask and an etching mask sequentially over the principal surface of the active regions of the substrate; the step of forming a second mask on and in self-alignment with the side walls of the first mask by a non-oxidizable mask thinner than the non-oxidizable mask of the first mask and an etching mask respectively; the step of etching the principal surface of the inactive regions of the substrate by using the first mask and the second mask; the step of forming the element separating insulating film over the principal surface of the inactive regions of the substrate by an oxidization using the first mask and the second mask; and the step of forming the channel s
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: September 22, 1998
    Assignees: Hitachi. Ltd., Hitachi VLSI Engineering Corporation
    Inventors: Jun Sugiura, Osamu Tsuchiya, Makoto Ogasawara, Fumio Ootsuka, Kazuyoshi Torii, Isamu Asano, Nobuo Owada, Mitsuaki Horiuchi, Tsuyoshi Tamaru, Hideo Aoki, Nobuhiro Otsuka, Seiichirou Shirai, Masakazu Sagawa, Yoshihiro Ikeda, Masatoshi Tsuneoka, Toru Kaga, Tomotsugu Shimmyo, Hidetsugu Ogishi, Osamu Kasahara, Hiromichi Enami, Atsushi Wakahara, Hiroyuki Akimori, Sinichi Suzuki, Keisuke Funatsu, Yoshinao Kawasaki, Tunehiko Tubone, Takayoshi Kogano, Ken Tsugane
  • Patent number: 5794763
    Abstract: A circuit breaker of the invention is formed of a container and a switch mechanism unit accommodated in the container. The switch mechanism unit is formed of a handle lever having a rotating shaft, a handle and lever arms; a movable contact having a movable contact point at one end with the other end rotatably joined with the lever arms; and a latch disposed to cross the rotating shaft and having a rotating shaft and an engaging arm protruding from the rotating shaft. A switch spring is disposed between the latch and the movable contact. The handle lever and the rotating shaft of the latch engage semi-circular bearing notches of a case and a cover of the container so that the switch mechanism unit is rotationally supported and held in the container.
    Type: Grant
    Filed: July 7, 1997
    Date of Patent: August 18, 1998
    Assignee: Fuji Electric Co., Ltd.
    Inventor: Makoto Ogasawara
  • Patent number: 5780882
    Abstract: Herein disclosed is a semiconductor integrated circuit device fabricating process for forming MISFETs over the principal surface in those active regions of a substrate, which are surrounded by inactive regions formed of an element separating insulating film and channel stopper regions, comprising: the step of for forming a first mask by a non-oxidizable mask and an etching mask sequentially over the principal surface of the active regions of the substrate; the step of forming a second mask on and in self-alignment with the side walls of the first mask by a non-oxidizable mask thinner than the non-oxidizable mask of the first mask and an etching mask respectively; the step of etching the principal surface of the inactive regions of the substrate by using the first mask and the second mask; the step of forming the element separating insulating film over the principal surface of the inactive regions of the substrate by an oxidization using the first mask and the second mask; and the step of forming the channel s
    Type: Grant
    Filed: June 1, 1995
    Date of Patent: July 14, 1998
    Assignees: Hitachi, Ltd., Hitachi VLSI Engineering Corp.
    Inventors: Jun Sugiura, Osamu Tsuchiya, Makoto Ogasawara, Fumio Ootsuka, Kazuyoshi Torii, Isamu Asano, Nobuo Owada, Mitsuaki Horiuchi, Tsuyoshi Tamaru, Hideo Aoki, Nobuhiro Otsuka, Seiichirou Shirai, Masakazu Sagawa, Yoshihiro Ikeda, Masatoshi Tsuneoka, Toru Kaga, Tomotsugu Shimmyo, Hidetsugu Ogishi, Osamu Kasahara, Hiromichi Enami, Atsushi Wakahara, Hiroyuki Akimori, Sinichi Suzuki, Keisuke Funatsu, Yoshinao Kawasaki, Tunehiko Tubone, Takayoshi Kogano, Ken Tsugane
  • Patent number: 5739589
    Abstract: Herein disclosed is a semiconductor integrated circuit device fabricating process for forming MISFETs over the principal surface in those active regions of a substrate, which are surrounded by inactive regions formed of an element separating insulating film and channel stopper regions, comprising: the step of for forming a first mask by a non-oxidizable mask and an etching mask sequentially over the principal surface of the active regions of the substrate; the step of forming a second mask on and in self-alignment with the side walls of the first mask by a non-oxidizable mask thinner than the non-oxidizable mask of the first mask and an etching mask respectively; the step of etching the principal surface of the inactive regions of the substrate by using the first mask and the second mask; the step of forming the element separating insulating film over the principal surface of the inactive regions of the substrate by an oxidization using the first mask and the second mask; and the step of forming the channel s
    Type: Grant
    Filed: June 3, 1996
    Date of Patent: April 14, 1998
    Assignees: Hitachi, Ltd., Hitachi VLSI Engineering Corp.
    Inventors: Jun Sugiura, Osamu Tsuchiya, Makoto Ogasawara, Fumio Ootsuka, Kazuyoshi Torii, Isamu Asano, Nobuo Owada, Mitsuaki Horiuchi, Tsuyoshi Tamaru, Hideo Aoki, Nobuhiro Otsuka, Seiichirou Shirai, Masakazu Sagawa, Yoshihiro Ikeda, Masatoshi Tsuneoka, Toru Kaga, Tomotsugu Shimmyo, Hidetsugu Ogishi, Osamu Kasahara, Hiromichi Enami, Atsushi Wakahara, Hiroyuki Akimori, Sinichi Suzuki, Keisuke Funatsu, Yoshinao Kawasaki, Tunehiko Tubone, Takayoshi Kogano, Ken Tsugane
  • Patent number: 5557147
    Abstract: Herein disclosed is a semiconductor integrated circuit device fabricating process for forming MISFETs over the principal surface in those active regions of a substrate, which are surrounded by inactive regions formed of an element separating insulating film and channel stopper regions, comprising: the step of for forming a first mask by a non-oxidizable mask and an etching mask sequentially over the principal surface of the active regions of the substrate; the step of forming a second mask on and in self-alignment with the side walls of the first mask by a non-oxidizable mask thinner than the non-oxidizable mask of the first mask and an etching mask respectively; the step of etching the principal surface of the inactive regions of the substrate by using the first mask and the second mask; the step of forming the element separating insulating film over the principal surface of the inactive regions of the substrate by an oxidization using the first mask and the second mask; and the step of forming the channel s
    Type: Grant
    Filed: April 19, 1994
    Date of Patent: September 17, 1996
    Assignees: Hitachi, Ltd., Hitachi ULSI Engineering Corporation
    Inventors: Jun Sugiura, Osamu Tsuchiya, Makoto Ogasawara, Fumio Ootsuka, Kazuyoshi Torii, Isamu Asano, Nobuo Owada, Mitsuaki Horiuchi, Tsuyoshi Tamaru, Hideo Aoki, Nobuhiro Otsuka, Seiichirou Shirai, Masakazu Sagawa, Yoshihiro Ikeda, Masatoshi Tsuneoka, Toru Kaga, Tomotsugu Shimmyo, Hidetsugu Ogishi, Osamu Kasahara, Hiromichi Enami, Atsushi Wakahara, Hiroyuki Akimori, Sinichi Suzuki, Keisuke Funatsu, Yoshinao Kawasaki, Tunehiko Tubone, Takayoshi Kogano, Ken Tsugane
  • Patent number: 5512194
    Abstract: There are provided acicular berthollide particles comprising crystalline particles expressed by the formula FeOx (1.33.ltoreq.x<1.5) and modified with a specific amount of zinc ions and a process producing the same which comprises the steps of oxidizing acicular magnetic iron oxide particles expressed by the formula FeOx (1.0<x<1.33) and modified with a specific amount of zinc ions which are produced by (a) heating and dehydrating acicular hydrous iron oxide particles containing a specific amount of a zinc component, reducing, and heating the particles under specific conditions, or (b) reducing acicular iron oxide particles containing a specific amount of a zinc component and heating the particles under specific conditions, or (c) heating acicular magnetic iron oxide particles expressed by the formula FeOx (1.0<x<1.33) containing a specific amount of zinc ions under specific conditions.
    Type: Grant
    Filed: June 7, 1994
    Date of Patent: April 30, 1996
    Assignee: Ishihara Sangyo Kaisha, Ltd.
    Inventors: Makoto Ogasawara, Masakazu Yada, Kaoru Sakurai, Kazuya Haga, Masahide Miyashita, Yasumasa Hirai
  • Patent number: 5331191
    Abstract: Herein disclosed is a semiconductor integrated circuit device fabricating process for forming MISFETs over the principal surface in those active regions of a substrate, which are surrounded by inactive regions formed of an element separating insulating film and channel stopper regions, comprising: the step of for forming a first mask by a non-oxidizable mask and an etching mask sequentially over the principal surface of the active regions of the substrate; the step of forming a second mask on and in self-alignment with the side walls of the first mask by a non-oxidizable mask thinner than the non-oxidizable mask of the first mask and an etching mask respectively; the step of etching the principal surface of the inactive regions of the substrate by using the first mask and the second mask; the step of forming the element separating insulating film over the principal surface of the inactive regions of the substrate by an oxidization using the first mask and the second mask; and the step of forming the channel s
    Type: Grant
    Filed: September 30, 1992
    Date of Patent: July 19, 1994
    Assignees: Hitachi, Ltd., Hitachi VLSI Engineering Corp.
    Inventors: Jun Sugiura, Osamu Tsuchiya, Makoto Ogasawara, Fumio Ootsuka, Kazuyoshi Torii, Isamu Asano, Nobuo Owada, Mitsuaki Horiuchi, Tsuyoshi Tamaru, Hideo Aoki, Nobuhiro Otsuka, Seiichirou Shirai, Masakazu Sagawa, Yoshihiro Ikeda, Masatoshi Tsuneoka, Toru Kaga, Tomotsugu Shimmyo, Hidetsugu Ogishi, Osamu Kasahara, Hiromichi Enami, Atsushi Wakahara, Hiroyuki Akimori, Sinichi Suzuki, Keisuke Funatsu, Yoshinao Kawasaki, Tunehiko Tubone, Takayoshi Kogano, Ken Tsugane
  • Patent number: 5202275
    Abstract: Herein disclosed is a semiconductor integrated circuit device fabricating process for forming MISFETs over the principal surface in those active regions of a substrate, which are surrounded by inactive regions formed of an element separating insulating film and channel stopper regions, comprising: the step of for forming a first mask by a non-oxidizable mask and an etching mask sequentially over the principal surface of the active regions of the substrate; the step of forming a second mask on and in self-alignment with the side walls of the first mask by a non-oxidizable mask thinner than the non-oxidizable mask of the first mask and an etching mask respectively; the step of etching the principal surface of the inactive regions of the substrate by using the first mask and the second mask; the step of forming the element separating insulating film over the principal surface of the inactive regions of the substrate by an oxidization using the first mask and the second mask; and the step of forming the channel s
    Type: Grant
    Filed: March 20, 1990
    Date of Patent: April 13, 1993
    Assignees: Hitachi Ltd., Hitachi VLSI Engineering Corp.
    Inventors: Jun Sugiura, Osamu Tsuchiya, Makoto Ogasawara, Fumio Ootsuka, Kazuyoshi Torii, Isamu Asano, Nobuo Owada, Mitsuaki Horiuchi, Tsuyoshi Tamaru, Hideo Aoki, Nobuhiro Otsuka, Seiichirou Shirai, Masakazu Sagawa, Yoshihiro Ikeda, Masatoshi Tsuneoka, Toru Kaga, Tomotsugu Shimmyo, Hidetsugu Ogishi, Osamu Kasahara, Hiromichi Enami, Atsushi Wakahara, Hiroyuki Akimori, Sinichi Suzuki, Keisuke Funatsu, Yoshinao Kawasaki, Tunehiko Tubone, Takayoshi Kogano, Ken Tsugane
  • Patent number: 5041307
    Abstract: A process for producing magnetic ion oxide particles for magnetic rcording which comprises heat-treating a magnetic iron oxide particles of magnetite, berthollide or maghemite as a starting materials, in the presence of a zinc component or both a zinc component and a silicon component at a temperature of 400.degree. to 700.degree. C. in a specific atmosphere, and if necessary, subjecting the heat-treated particles to wet treatment and/or dry treatment, thereby doping the particles with zinc ions resulting in magnetic iron oxide particles having an improved saturation magnetization, a proportion of said zinc ions being 2 to 9 at. % by weight relative to the total amount of iron ions.
    Type: Grant
    Filed: November 28, 1989
    Date of Patent: August 20, 1991
    Assignee: Ishihara Sangyo Kaisha, Ltd.
    Inventors: Arata Koyama, Makoto Ogasawara, Shigeru Takatori
  • Patent number: 4974060
    Abstract: A dynamic RAM having memory cells each being constructed of a MISFET and a capacitor element which are formed in the shape of a pillar on the domain of a semiconductor substrate where a bit line and a word line intersect. The transfer MISFET is formed at the lower part of the pillar-shaped memory cell, while the capacitor element is formed at the upper part thereof, and a plate electrode to which the reference potential of the capacitor element is applied is isolated from the semiconductor substrate, so that 1/2 V.sub.cc can be adopted as the reference potential of the capacitor element.
    Type: Grant
    Filed: February 1, 1989
    Date of Patent: November 27, 1990
    Assignee: Hitachi, Ltd.
    Inventor: Makoto Ogasawara