Patents by Inventor Iwao Kunishima

Iwao Kunishima 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: 7022531
    Abstract: A semiconductor memory device including a memory cell block having a plurality of memory transistors formed on a semiconductor substrate. The memory transistors include first and second impurity-diffused regions and a gate formed therebetween. A plurality of memory cells are also included in the memory cell block and have lower electrodes connected to the first impurity-diffused regions, ferroelectric films formed on the lower electrodes and first upper electrodes formed on the ferroelectric films and connected to the second impurity-diffused regions. Further included are block selecting transistors formed on the semiconductor substrate and being connected to one end of the memory cell block. Second upper electrodes are also formed adjoined to the block selecting transistors and being disconnected from the first upper electrode of the memory cells.
    Type: Grant
    Filed: July 15, 2003
    Date of Patent: April 4, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tohru Ozaki, Iwao Kunishima, Toyota Morimoto, Hiroyuki Kanaya
  • Publication number: 20060030110
    Abstract: A semiconductor device including a ferroelectric random access memory, which has a structure suitable for miniaturization and easy to manufacture, and having less restrictions on materials to be used, comprises a field effect transistor formed on a surface area of a semiconductor wafer, a trench ferroelectric capacitor formed in the semiconductor wafer in one source/drain of the field effect transistor, wherein one electrode thereof is connected to the source/drain, and a wiring formed in the semiconductor wafer and connected to the other electrode of the trench ferroelectric capacitor.
    Type: Application
    Filed: October 7, 2004
    Publication date: February 9, 2006
    Inventors: Yoshinori Kumura, Iwao Kunishima, Tohru Ozaki
  • Publication number: 20060022241
    Abstract: A transistor is formed in a surface region of a semiconductor substrate. A capacitor is formed above the transistor, and has a first electrode, a second electrode, and a dielectric film formed between the first and second electrodes. A first contact is formed on a side surface portion of the capacitor so as to be close to at least a portion of the capacitor, and connected to one of source/drain regions. A side insulating film is formed, in contact with at least the capacitor, on the sidewalls of the first contact.
    Type: Application
    Filed: October 6, 2004
    Publication date: February 2, 2006
    Inventors: Yoshiro Shimojo, Yoshinori Kumura, Iwao Kunishima
  • Publication number: 20060017086
    Abstract: There is provided a semiconductor device having a ferroelectric capacitor formed on a semiconductor substrate covered with an insulator film, wherein the ferroelectric capacitor comprises: a bottom electrode formed on the insulator film; a ferroelectric film formed on the bottom electrode; and a top electrode formed on the ferroelectric film. The ferroelectric film has a stacked structure of either of two-layer-ferroelectric film or three-layer-ferroelectric film. The upper ferroelectric film is metallized and prevents hydrogen from diffusing in lower ferroelectric layer. Crystal grains of the stacked ferroelectric films are preferably different.
    Type: Application
    Filed: September 13, 2005
    Publication date: January 26, 2006
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hiroyuki Kanaya, Iwao Kunishima, Koji Yamakawa, Tsuyoshi Iwamoto, Hiroshi Mochizuki, Yoshinori Kumura
  • Publication number: 20060002170
    Abstract: A semiconductor storage device wherein a plurality of ferroelectric capacitors are sufficiently covered with a hydrogen barrier film formed thereon comprises a field effect transistor formed on one surface side of a semiconductor substrate, a plurality of ferroelectric capacitors formed close to each other above the field effect transistor, an insulting film configured to cover the plurality of ferroelectric capacitors and planarised a space between adjacent ferroelectric capacitors in a self-aligned manner during formation thereof, and a hydrogen barrier film formed on the insulating film.
    Type: Application
    Filed: September 1, 2004
    Publication date: January 5, 2006
    Inventors: Yoshinori Kumura, Yoshiro Shimojo, Iwao Kunishima, Tohru Ozaki
  • Patent number: 6982444
    Abstract: There is provided a semiconductor device having a ferroelectric capacitor formed on a semiconductor substrate covered with an insulator film, wherein the ferroelectric capacitor comprises: a bottom electrode formed on the insulator film; a ferroelectric film formed on the bottom electrode; and a top electrode formed on the ferroelectric film. The ferroelectric film has a stacked structure of either of two-layer-ferroelectric film or three-layer-ferroelectric film. The upper ferroelectric film is metallized and prevents hydrogen from diffusing in lower ferroelectric layer. Crystal grains of the stacked ferroelectric films are preferably different.
    Type: Grant
    Filed: May 22, 2003
    Date of Patent: January 3, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroyuki Kanaya, Iwao Kunishima, Koji Yamakawa, Tsuyoshi Iwamoto, Hiroshi Mochizuki, Yoshinori Kumura
  • Patent number: 6982453
    Abstract: A semiconductor device having a semiconductor substrate; an insulating film formed on said semiconductor substrate; a ferroelectric capacitor having a lower electrode, a ferroelectric film and an upper electrode which are stacked sequentially on the insulating film; a first hydrogen barrier film; a first inter-layer insulating film covering said ferroelectric capacitor; and a second inter-layer insulating film stacked on the first inter-layer insulating film, the first hydrogen barrier film being interposed between the first and second interlayer insulating films is proposed.
    Type: Grant
    Filed: June 25, 2003
    Date of Patent: January 3, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroyuki Kanaya, Toyota Morimoto, Osamu Hidaka, Yoshinori Kumura, Iwao Kunishima, Tsuyoshi Iwamoto
  • Patent number: 6972990
    Abstract: A ferro-electric memory device includes a gate electrode which is formed on a semiconductor substrate, first and second diffusion layers which are formed in the semiconductor substrate, a first contact which is electrically connected to the first diffusion layer, a first oxygen barrier film having insulating properties, which is formed on the first contact, a second contact which is electrically connected to the first contact, a second oxygen barrier film having insulating properties, which is formed on the second contact, a ferro-electric capacitor which has a lower electrode, a ferro-electric film, and an upper electrode, a third contact which is electrically connected to the upper electrode, a first interconnection which is electrically connected to the second and third contacts, and a third oxygen barrier film having insulating properties, which is arranged between the ferro-electric capacitor and the second contact and brought into contact with the first oxygen barrier film.
    Type: Grant
    Filed: June 2, 2004
    Date of Patent: December 6, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshinori Kumura, Tohru Ozaki, Hiroyuki Kanaya, Iwao Kunishima, Yoshiro Shimojo
  • Patent number: 6967367
    Abstract: A ferro-electric memory device includes a semiconductor substrate, a first transistor formed on the semiconductor substrate, and a first ferro-electric capacitor electrically connected to the first transistor and formed of a first capacitor material layer having a first lower electrode, a first ferro-electric film, and a first upper electrode, the first ferro-electric capacitor being thicker at its central portion than at its ends.
    Type: Grant
    Filed: March 22, 2004
    Date of Patent: November 22, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshinori Kumura, Iwao Kunishima
  • Publication number: 20050207202
    Abstract: A ferro-electric memory device includes a gate electrode which is formed on a semiconductor substrate, first and second diffusion layers which are formed in the semiconductor substrate, a first contact which is electrically connected to the first diffusion layer, a first oxygen barrier film having insulating properties, which is formed on the first contact, a second contact which is electrically connected to the first contact, a second oxygen barrier film having insulating properties, which is formed on the second contact, a ferro-electric capacitor which has a lower electrode, a ferro-electric film, and an upper electrode, a third contact which is electrically connected to the upper electrode, a first interconnection which is electrically connected to the second and third contacts, and a third oxygen barrier film having insulating properties, which is arranged between the ferro-electric capacitor and the second contact and brought into contact with the first oxygen barrier film.
    Type: Application
    Filed: June 2, 2004
    Publication date: September 22, 2005
    Inventors: Yoshinori Kumura, Tohru Ozaki, Hiroyuki Kanaya, Iwao Kunishima, Yoshiro Shimojo
  • Publication number: 20050176199
    Abstract: A semiconductor memory device including a memory cell block having a plurality of memory transistors formed on a semiconductor substrate. The memory transistors include first and second impurity-diffused regions and a gate formed therebetween. A plurality of memory cells are also included in the memory cell block and have lower electrodes connected to the first impurity-diffused regions, ferroelectric films formed on the lower electrodes and first upper electrodes formed on the ferroelectric films and connected to the second impurity-diffused regions. Further included are block selecting transistors formed on the semiconductor substrate and being connected to one end of the memory cell block. Second upper electrodes are also formed adjoined to the block selecting transistors and being disconnected from the first upper electrode of the memory cells.
    Type: Application
    Filed: July 15, 2003
    Publication date: August 11, 2005
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Tohru Ozaki, Iwao Kunishima, Toyota Morimoto, Hiroyuki Kanaya
  • Publication number: 20050167716
    Abstract: A ferro-electric memory device includes a semiconductor substrate, a first transistor formed on the semiconductor substrate, and a first ferro-electric capacitor electrically connected to the first transistor and formed of a first capacitor material layer having a first lower electrode, a first ferro- electric film, and a first upper electrode, the first ferro-electric capacitor being thicker at its central portion than at its ends.
    Type: Application
    Filed: March 22, 2004
    Publication date: August 4, 2005
    Inventors: Yoshinori Kumura, Iwao Kunishima
  • Publication number: 20050118795
    Abstract: A semiconductor memory device includes a semiconductor substrate having a first region and a second region, a transistor placed in the first region of the semiconductor substrate, a first insulating film formed on the semiconductor substrate in the first and second regions and on the transistor, a first ferroelectric capacitor formed on the first insulating film in the first region and electrically connected to the transistor, a hydrogen barrier film formed above the first ferroelectric capacitor and above the first insulating film in the first and second regions, a first contact penetrating the hydrogen barrier film in the first region and electrically connected to the first ferroelectric capacitor, and a second contact which penetrates the hydrogen barrier film in the second region and which is in a floating state.
    Type: Application
    Filed: July 8, 2004
    Publication date: June 2, 2005
    Inventors: Osamu Hidaka, Iwao Kunishima, Hiroyuki Kanaya
  • Publication number: 20050002266
    Abstract: A semiconductor device includes a switching element formed on a semiconductor substrate, a first interconnect layer formed on the semiconductor substrate and having a first wiring connected to one terminal of the switching element, a ferroelectric capacitor formed on the first interconnect layer and having a first electrode connected to the one terminal of the switching element via the first wiring, a first protective film formed on the ferroelectric capacitor and the first interconnect layer, a second interconnect layer formed on the first protective film and having a second wiring connected to a second electrode of the ferroelectric capacitor and a first interlayer insulating film having a dielectric constant of 4 or more, and a third interconnect layer formed on the second interconnect layer and having a second interlayer insulating film with a dielectric constant of less than 4.
    Type: Application
    Filed: April 20, 2004
    Publication date: January 6, 2005
    Inventors: Hiroyuki Kanaya, Iwao Kunishima
  • Publication number: 20040195601
    Abstract: A semiconductor memory device includes a semiconductor substrate, a first transistor formed on the semiconductor substrate and including a first gate electrode and first and second diffusion layers, a first contact connected to the first diffusion layer, a first conductive oxygen barrier film electrically connected to the first contact and covering at least the upper surface of the first contact, a first ferroelectric capacitor including a first electrode, a second electrode, and a first ferroelectric film interposed between the first and second electrodes, and a first connecting member connected to the first electrode and to the first conductive oxygen barrier film.
    Type: Application
    Filed: June 6, 2003
    Publication date: October 7, 2004
    Inventors: Yoshinori Kumura, Iwao Kunishima, Tohru Ozaki, Hiroyuki Kanaya, Shinichi Watanabe
  • Publication number: 20040084701
    Abstract: A semiconductor device having a semiconductor substrate; an insulating film formed on said semiconductor substrate; a ferroelectric capacitor having a lower electrode, a ferroelectric film and an upper electrode which are stacked sequentially on the insulating film; a first hydrogen barrier film; a first inter-layer insulating film covering said ferroelectric capacitor; and a second inter-layer insulating film stacked on the first inter-layer insulating film, the first hydrogen barrier film being interposed between the first and second interlayer insulating films is proposed.
    Type: Application
    Filed: June 25, 2003
    Publication date: May 6, 2004
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hiroyuki Kanaya, Toyota Morimoto, Osamu Hidaka, Yoshinori Kumura, Iwao Kunishima, Tsuyoshi Iwamoto
  • Publication number: 20040056290
    Abstract: There is provided a semiconductor device having a ferroelectric capacitor formed on a semiconductor substrate covered with an insulator film, wherein the ferroelectric capacitor comprises: a bottom electrode formed on the insulator film; a ferroelectric film formed on the bottom electrode; and a top electrode formed on the ferroelectric film. The ferroelectric film has a stacked structure of either of two-layer-ferroelectric film or three-layer-ferroelectric film. The upper ferroelectric film is metallized and prevents hydrogen from diffusing in lower ferroelectric layer. Crystal grains of the stacked ferroelectric films are preferably different.
    Type: Application
    Filed: May 22, 2003
    Publication date: March 25, 2004
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hiroyuki Kanaya, Iwao Kunishima, Koji Yamakawa, Tsuyoshi Iwamoto, Hiroshi Mochizuki, Yoshinori Kumura
  • Patent number: 6680499
    Abstract: Provided are a semiconductor memory device that permits increasing the degree of integration without decreasing the capacitance of the capacitor included in a memory cell, and a method of manufacturing the particular semiconductor memory device. Specifically, provided are a semiconductor memory device, comprising a semiconductor substrate, an interlayer insulating film formed on the semiconductor substrate, a first electrode formed on the interlayer insulating film, a first ferroelectric film formed on the first electrode, a second electrode formed on the first ferroelectric film, a second ferroelectric film formed on the second electrode, and a third electrode formed on the second ferroelectric film, and a method of manufacturing the particular semiconductor memory device.
    Type: Grant
    Filed: November 19, 2001
    Date of Patent: January 20, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshinori Kumura, Hiroyuki Kanaya, Iwao Kunishima
  • Patent number: 6611015
    Abstract: A semiconductor memory device including a memory cell block having a plurality of memory transistors formed on a semiconductor substrate. The memory transistors include first and second impurity-diffused regions and a gate formed therebetween. A plurality of memory cells are also included in the memory cell block and have lower electrodes connected to the first impurity-diffused regions, ferroelectric films formed on the lower electrodes and first upper electrodes formed on the ferroelectric films and connected to the second impurity-diffused regions. Further included are block selecting transistors formed on the semiconductor substrate and being connected to one end of the memory cell block. Second upper electrodes are also formed adjoined to the block selecting transistors and being disconnected from the first upper electrode of the memory cells.
    Type: Grant
    Filed: September 20, 2001
    Date of Patent: August 26, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tohru Ozaki, Iwao Kunishima, Toyota Morimoto, Hiroyuki Kanaya
  • Patent number: 6611014
    Abstract: A semiconductor device having a semiconductor substrate; an insulating film formed on said semiconductor substrate; a ferroelectric capacitor having a lower electrode, a ferroelectric film and an upper electrode which are stacked sequentially on the insulating film; a first hydrogen barrier film; a first inter-layer insulating film covering said ferroelectric capacitor; and a second inter-layer insulating film stacked on the first inter-layer insulating film, the first hydrogen barrier film being interposed between the first and second interlayer insulating films is proposed.
    Type: Grant
    Filed: May 12, 2000
    Date of Patent: August 26, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroyuki Kanaya, Toyota Morimoto, Osamu Hidaka, Yoshinori Kumura, Iwao Kunishima, Tsuyoshi Iwamoto