Patents by Inventor Yusuke Kohyama

Yusuke Kohyama 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: 6551894
    Abstract: First and second wirings are formed on a first insulating film. Each of the wirings is arranged so that a conductive film, a silicon oxide film and a silicon nitride film are laminated. Thereafter, a silicon oxide insulating film on the whole surface. The silicon oxide insulating film is etched so that a contact hole is formed between the first and second wirings. Since the silicon oxide film and the silicon nitride film exist on the conductive film of each wiring, the conductive film is not exposed at the time of etching. Thereafter, an insulating film is formed on a side wall of the contact hole, and the conductive film exposed through the contact hole is covered by the insulating film.
    Type: Grant
    Filed: August 3, 2000
    Date of Patent: April 22, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yusuke Kohyama, Takashi Ohsawa, Shizuo Sawada
  • Patent number: 6548844
    Abstract: A semiconductor device having a structure capable of restraining deterioration of a dielectric film of a capacitor even when annealing is performed in a hydrogen-containing atmosphere. This semiconductor device includes one electrode or a plurality of dispersion electrodes formed in a dispersed manner above a semiconductor substrate, and a plate electrode commonly facing the one electrode or dispersion electrodes via respective dielectric films. This plate electrode includes a lower conductive layer formed on the dielectric films, a barrier layer formed on the lower conductive layer and an upper conductive layer formed on the barrier layer.
    Type: Grant
    Filed: June 16, 2000
    Date of Patent: April 15, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiaki Fukuzumi, Yusuke Kohyama
  • Patent number: 6534814
    Abstract: The invention provides a structure which enables a junction leak current to be reduced without reducing a capacitor area. A trench is formed in the surface of a substrate such that it is connected to a conductive region for a transistor. The structure is characterized by comprising a capacitor electrode formed on the inner peripheral surface of the trench and having its upper edge portion located below the conductive region, an insulating layer projecting inward of the trench at least from the upper edge portion of the capacitor electrode to the conductive region, thereby narrowing the diameter of the trench, a capacitor insulating film coated on the capacitor electrode, and a capacitor electrode filling the trench and contacting the capacitor insulating film.
    Type: Grant
    Filed: February 4, 2000
    Date of Patent: March 18, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Junichiro Iba, Yusuke Kohyama
  • Patent number: 6506634
    Abstract: A semiconductor memory device comprises: a memory cell array including memory cells arranged in the form of a matrix; a redundant cell array including redundant cells arranged for relieving a defective memory cell of the memory cell array; a defective address memory circuit including first and second memory circuits using different programming methods for storing an address of the defective memory cell of the memory cell array; and a substitution control circuit for controlling the substitution of one of the redundant cells of the redundant cell array for the defective memory cell of the memory cell array on the basis of memory data of the defective address memory circuit. Thus, it is possible to provide a semiconductor memory device capable of reducing the area occupied by a defective address memory circuit and surely carrying out defect relief, and a method for producing the same.
    Type: Grant
    Filed: June 8, 2000
    Date of Patent: January 14, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Yusuke Kohyama
  • Patent number: 6448618
    Abstract: In a DRAM, a plurality of first MOSFETs are formed in a cell region on a semiconductor substrate based on the minimum design rule, and a first gate side-wall having a side-wall insulation film is formed on the side-wall portion of a first gate electrode of each of the first MOSFETs. At least one second MOSFET is formed in a peripheral circuit region on the semiconductor substrate, and a second gate side-wall having side-wall insulation films is formed on the side-wall portion of a second gate electrode of the second MOSFET. Both the first MOSFETs, which is capable of forming a fine contact hole self-aligned with the first gate electrode, and the second MOSFET, which is capable of sufficiently mitigating the parasitic resistance while suppressing the short channel effect, can be formed on the same substrate.
    Type: Grant
    Filed: August 18, 2000
    Date of Patent: September 10, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Satoshi Inaba, Tohru Ozaki, Yusuke Kohyama, Kazumesa Sunouchi
  • Publication number: 20020072183
    Abstract: The invention provides a structure which enables a junction leak current to be reduced without reducing a capacitor area. A trench is formed in the surface of a substrate such that it is connected to a conductive region for a transistor. The structure is characterized by comprising a capacitor electrode formed on the inner peripheral surface of the trench and having its upper edge portion located below the conductive region, an insulating layer projecting inward of the trench at least from the upper edge portion of the capacitor electrode to the conductive region, thereby narrowing the diameter of the trench, a capacitor insulating film coated on the capacitor electrode, and a capacitor electrode filling the trench and contacting the capacitor insulating film.
    Type: Application
    Filed: February 4, 2000
    Publication date: June 13, 2002
    Inventors: Junichiro Iba, Yusuke Kohyama
  • Patent number: 6403444
    Abstract: This invention provides a capacitor including a metal lower electrode having an undulated shape and an improved electrode area, and a method of manufacturing the same. A capacitor for data storage is formed on a semiconductor substrate (not shown) via an insulating interlayer having a contact plug. The capacitor has a lower electrode whose inner and outer surfaces are rough or undulated such that one surface has a shape conforming to the shape of the other surface, a dielectric film formed to cover the surfaces of the lower electrode, and an upper electrode formed to cover the lower electrode via the dielectric film. The lower electrode has a cylindrical shape with an open upper end. The lower electrode is connected to a cell transistor through the contact plug. The lower electrode is formed from a metal or a metal oxide.
    Type: Grant
    Filed: March 8, 2001
    Date of Patent: June 11, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiaki Fukuzumi, Yusuke Kohyama
  • Patent number: 6362042
    Abstract: Provided is a semiconductor device and a method of manufacturing the semiconductor device having a stacked type capacitor excellent in storage capacity, breakdown voltage and reliability. A storage node electrode (Ru) of the stacked-type capacitor is formed on a contact hole of the underlying insulating film by the steps of forming the side wall of the contact hole diagonally at a taper angle within the range of 90 to 110°, forming a storage node electrode on the inner wall surface of the contact hole, filling SOG in the contact hole, etching off the Ru film on the insulating film using SOG as a mask, and etching off the Ru film formed on the upper peripheral region of the inner wall in the depth direction of the contact hole. Thereafter, the dielectric film of the stacked-type capacitor formed of a (Ba, Sr) TiO3 thin film is formed on the Ru storage node electrode. In this manner, it is possible to obtain a stack-type capacitor having a drastically-improved step coverage and a high breakdown voltage.
    Type: Grant
    Filed: September 19, 2000
    Date of Patent: March 26, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Keiji Hosotani, Yusuke Kohyama
  • Publication number: 20020011618
    Abstract: Capacitors are formed in the trenches made in an interlayer insulator made of silicon oxide. An insulating film (e.g., a silicon nitride film) is provided on the sides of each trench of the interlayer insulator. A storage electrode made of ruthenium or the like is provided in each trench of the interlayer insulator. A capacitor insulating film made of BSTO or the like is formed on the storage electrode. A plate electrode made of ruthenium or the like is formed on the capacitor insulating film. The plate electrode is common to all capacitors provided. Any two adjacent capacitors are electrically isolated by the interlayer insulator and the insulating film provided on the sides of the trenches of the interlayer insulator.
    Type: Application
    Filed: September 17, 2001
    Publication date: January 31, 2002
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Yutaka Ishibashi, Yusuke Kohyama, Tohru Ozaki
  • Publication number: 20020003280
    Abstract: A semiconductor device comprises capacitor structures, each having a first lower electrode, a first insulating film formed on the first lower electrode and a first upper electrode formed on the first insulating film, and electric fuse elements, each having a second lower electrode, a second insulating film formed on the second lower electrode and having an impurity concentration higher than that of the first insulating film, and a second upper electrode formed on the second insulating film. The electric fuse elements have substantially the same structure as that of the capacitor structures, and they are formed on the same level as that of the capacitor structures. A writing voltage of the electric fuse element is determined by dielectric breakdown resistance of the second insulating film, which depends on the impurity concentration of the second insulating film.
    Type: Application
    Filed: June 28, 2001
    Publication date: January 10, 2002
    Inventor: Yusuke Kohyama
  • Publication number: 20010054764
    Abstract: In a semiconductor device, a wiring pattern groove is formed in a surface portion of a silicon oxide film provided above a semiconductor substrate. A wiring layer is buried into the wiring pattern groove with a barrier metal film interposed therebetween. The barrier metal film is selectively removed from each sidewall portion of the wiring pattern groove. In other words, the barrier metal film is left only on the bottom of the wiring pattern groove. Thus, a damascene wiring layer having a hollow section whose dielectric constant is low between each sidewall of the wiring pattern groove and each side of the wiring layer can be formed in the semiconductor device.
    Type: Application
    Filed: June 19, 2001
    Publication date: December 27, 2001
    Inventors: Hiroyuki Nitta, Yoshiaki Fukuzumi, Yusuke Kohyama
  • Patent number: 6333538
    Abstract: In a method of fabricating a COB DRAM cell, a polysilicon plug is formed on the source and drain in self-alignment with the gate electrode. A bit line contact and a storage electrode contact are formed on the polysilicon plug thereby to reduce the aspect ratio of both the bit line contact and the storage electrode contact. With the polysilicon plug formed in self-alignment with the gate electrode, short-circuiting of contacts of adjacent element regions and short-circuiting of the plugs of the source and drain will not occur, leading to high protection against misregistration. Moreover, an independent lithography process is not required for forming the polysilicon plug, and, therefore, the number of fabrication steps is reduced.
    Type: Grant
    Filed: September 2, 1999
    Date of Patent: December 25, 2001
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Keiji Hosotani, Yusuke Kohyama
  • Patent number: 6329683
    Abstract: In this DRAM, an SiO2 film for assuring the step coverage of cell-capacitor of cylinder type is left remained only in the peripheral circuit region. The capacitor upper electrode is formed extending from the memory cell array region to the peripheral circuit region. Since the capacitor upper electrode in the peripheral circuit region is disposed higher than the upper surface of the capacitor upper electrode which constitutes the cell-capacitor, this capacitor upper electrode in the peripheral circuit region is employed as a stopper for subsequently flattening the interlayer insulating film. Subsequently, the interlayer insulating film is employed as a mask for etching the capacitor upper electrode in the peripheral circuit region.
    Type: Grant
    Filed: December 27, 2000
    Date of Patent: December 11, 2001
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Yusuke Kohyama
  • Publication number: 20010049185
    Abstract: In a method of fabricating a COB DRAM cell, a polysilicon plug is formed on the source and drain in self-alignment with the gate electrode. A bit line contact and a storage electrode contact are formed on the polysilicon plug thereby to reduce the aspect ratio of both the bit line contact and the storage electrode contact. With the polysilicon plug formed in self-alignment with the gate electrode, short-circuiting of contacts of adjacent element regions and short-circuiting of the plugs of the source and drain will not occur, leading to high protection against misregistration. Moreover, an independent lithography process is not required for forming the polysilicon plug, and, therefore, the number of fabrication steps is reduced.
    Type: Application
    Filed: July 23, 2001
    Publication date: December 6, 2001
    Inventors: Keiji Hosotani, Yusuke Kohyama
  • Patent number: 6326691
    Abstract: A first contact hole for a bit line is formed in an interlayer insulating film, and a polysilicon film is formed on the inner surface of the contact hole and on the interlayer insulating film. Subsequently, the polysilicon film is subjected to isotropic dry etching using a resist as a mask, and the interlayer insulating film is subjected to RIE etching, thereby forming a second contact hole in the interlayer insulating film in a peripheral circuit region. Then, a laminated film is formed on the inner surface of the second contact hole and on the polysilicon film, and the second contact hole is filled with a filling member. The laminated film and the polysilicon film are patterned, thereby forming a bit line in a memory cell region.
    Type: Grant
    Filed: October 29, 1999
    Date of Patent: December 4, 2001
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yusuke Kohyama, Souichi Sugiura
  • Publication number: 20010045587
    Abstract: In a method of fabricating a COB DRAM cell, a polysilicon plug is formed on the source and drain in self-alignment with the gate electrode. A bit line contact and a storage electrode contact are formed on the polysilicon plug thereby to reduce the aspect ratio of both the bit line contact and the storage electrode contact. With the polysilicon plug formed in self-alignment with the gate electrode, short-circuiting of contacts of adjacent element regions and short-circuiting of the plugs of the source and drain will not occur, leading to high protection against misregistration. Moreover, an independent lithography process is not required for forming the polysilicon plug, and, therefore, the number of fabrication steps is reduced.
    Type: Application
    Filed: July 23, 2001
    Publication date: November 29, 2001
    Inventors: Keiji Hosotani, Yusuke Kohyama
  • Patent number: 6320260
    Abstract: A first contact hole for a bit line is formed in an interlayer insulating film, and a polysilicon film is formed on the inner surface of the contact hole and on the interlayer insulating film. Subsequently, the polysiliccon film is subjected to isotropic dry etching using a resist as a mask, and the interlayer insulating film is subjected to RIE etching, thereby forming a second contact hole in the interlayer insulating film in a peripheral circuit region. Then, a laminated film is formed on the inner surface of the second contact hole and on the polysilicon film, and the second contact hole is filled with a filling member. The laminated film and the polysilicon film are patterned, thereby forming a bit line in a memory cell region.
    Type: Grant
    Filed: August 8, 1996
    Date of Patent: November 20, 2001
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yusuke Kohyama, Souichi Sugiura
  • Patent number: 6303429
    Abstract: Capacitors are formed in the trenches made in an interlayer insulator made of silicon oxide. An insulating film (e.g., a silicon nitride film) is provided on the sides of each trench of the interlayer insulator. A storage electrode made of ruthenium or the like is provided in each trench of the interlayer insulator. A capacitor insulating film made of BSTO or the like is formed on the storage electrode. A plate electrode made of ruthenium or the like is formed on the capacitor insulating film. The plate electrode is common to all capacitors provided. Any two adjacent capacitors are electrically isolated by the interlayer insulator and the insulating film provided on the sides of the trenches of the interlayer insulator.
    Type: Grant
    Filed: October 2, 2000
    Date of Patent: October 16, 2001
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yutaka Ishibashi, Yusuke Kohyama, Tohru Ozaki
  • Publication number: 20010023110
    Abstract: This invention provides a capacitor including a metal lower electrode having an undulated shape and an improved electrode area, and a method of manufacturing the same. A capacitor for data storage is formed on a semiconductor substrate (not shown) via an insulating interlayer having a contact plug. The capacitor has a lower electrode whose inner and outer surfaces are rough or undulated such that one surface has a shape conforming to the shape of the other surface, a dielectric film formed to cover the surfaces of the lower electrode, and an upper electrode formed to cover the lower electrode via the dielectric film. The lower electrode has a cylindrical shape with an open upper end. The lower electrode is connected to a cell transistor through the contact plug. The lower electrode is formed from a metal or a metal oxide.
    Type: Application
    Filed: March 8, 2001
    Publication date: September 20, 2001
    Inventors: Yoshiaki Fukuzumi, Yusuke Kohyama
  • Publication number: 20010015472
    Abstract: A first concave portion for the element isolation, a second concave portion for an aligning mark, and a third concave portion for an anti-fuse portion are formed simultaneously within a silicon substrate. After a silicon oxide film is formed on the entire surface, the silicon oxide film positioned within the second and third concave portions is removed. Then, a gate insulating film is formed on the entire surface, followed by forming a polysilicon film on the gate insulating film. Further, these polysilicon film and gate insulating film are selectively removed to form a gate electrode above an element region, an aligning mark portion in the second concave portion, and a gate electrode for an anti-fuse portion on the bottom surface of the third concave portion.
    Type: Application
    Filed: February 15, 2001
    Publication date: August 23, 2001
    Inventors: Yoshiaki Fukuzumi, Yusuke Kohyama