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).
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Publication number: 20010012223Abstract: 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: ApplicationFiled: December 27, 2000Publication date: August 9, 2001Inventor: Yusuke Kohyama
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Patent number: 6268280Abstract: Trenches are formed in a silicon oxide film, a barrier metal film and tungsten film are formed, and the surface portion is polished to make the surface flat and form interconnection layers of the tungsten film in the trenches. Then, the tungsten film and barrier film are etched to form a stepped portions, a silicon nitride film is formed to fill the stepped portions, and the silicon nitride film is polished to make the surface flat. After this, the silicon oxide film is etched by use of a mask pattern to form contact holes in a self-aligned manner. Then, a silicon nitride film is formed and the surface portions is etched back to form side walls on the side walls of the contact holes and a barrier metal film and tungsten film are sequentially formed to fill the contact holes, then the tungsten film and barrier metal film are polished until the silicon oxide film and silicon nitride film are exposed, and as a result, the surface is made flat.Type: GrantFiled: November 9, 1998Date of Patent: July 31, 2001Assignee: Kabushiki Kaisha ToshibaInventor: Yusuke Kohyama
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Patent number: 6225230Abstract: Disclosed is a method of forming an element isolation insulating film by STI (shallow trench isolation) method, which permits effectively preventing a concave portion from being formed in an edge of the element isolation insulating film, permits decreasing the number of treating steps, and also permits facilitating the formation of the element isolation insulating film with a high yield. In forming the element isolation insulating film, a groove is formed in a surface region of a semiconductor substrate, followed by forming an insulating film on the entire surface to fill at least the groove. Then, a flattening treatment is applied at least once to remove the insulating film from the substrate surface such that the insulating film is left unremoved only within the groove. In place of a wet etching treatment, a mirror-polishing method is employed for the last flattening treatment.Type: GrantFiled: May 22, 1997Date of Patent: May 1, 2001Assignee: Kabushiki Kaisha ToshibaInventors: Hiroyuki Nitta, Yusuke Kohyama
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Patent number: 6222722Abstract: 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: GrantFiled: April 1, 1999Date of Patent: April 24, 2001Assignee: Kabushiki Kaisha ToshibaInventors: Yoshiaki Fukuzumi, Yusuke Kohyama
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Patent number: 6198122Abstract: A semiconductor memory includes a semiconductor substrate, a memory cell portion formed on the substrate and including stacked capacitors formed on the substrate, each having a storage electrode formed on a bottom surface of a recess in an insulating layer, a capacitor insulating film formed on the storage electrode, and a plate electrode formed on the capacitor insulating film and lower than an upper edge of the recess, and a first multilayered interconnecting layer having an interconnecting layer including a plate interconnection connected to the plate electrode, and a peripheral circuit portion formed adjacent to the memory cell portion on the substrate and comprising a second multilayered interconnecting layer.Type: GrantFiled: February 19, 1998Date of Patent: March 6, 2001Assignee: Kabushiki Kaisha ToshibaInventors: Mariko Habu, Yusuke Kohyama, Toru Ozaki, Keiji Hosotani
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Patent number: 6197675Abstract: A semiconductor memory device comprises a semiconductor substrate, a first conducting layer formed above the main surface of the semiconductor substrate, a second conducting layer formed above the first conducting layer through a first insulating layer and connected to the first conducting layer through a first via-conductor formed in a first contact hole formed in the first insulating layer, and a third conducting layer formed beneath the second conducting layer through a second insulating layer and connected to the second conducting layer through a second via-conductor formed in a second contact hole formed in the second insulating layer, in which an angle formed by a tangent to an inner wall of the first contact hole and a normal to the first conducting layer at a portion of the first conducting layer at which the first contact hole is in contact with the first conducting layer, is larger than an angle formed by a tangent to an inner wall of the second contact hole and a normal to the third conducting layeType: GrantFiled: December 7, 1999Date of Patent: March 6, 2001Assignee: Kabushiki Kaisha ToshibaInventors: Yoshiaki Fukuzumi, Yusuke Kohyama
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Patent number: 6175130Abstract: 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: GrantFiled: November 23, 1999Date of Patent: January 16, 2001Assignee: Kabushiki Kaisha ToshibaInventors: Keiji Hosotani, Yusuke Kohyama
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Patent number: 6153476Abstract: 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: GrantFiled: February 25, 1998Date of Patent: November 28, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Satoshi Inaba, Tohru Ozaki, Yusuke Kohyama, Kazumasa Sunouchi
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Patent number: 6150690Abstract: 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: GrantFiled: February 25, 1998Date of Patent: November 21, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Yutaka Ishibashi, Yusuke Kohyama, Toru Ozaki
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Patent number: 6140673Abstract: In a high-integration DRAM device using a SOI substrate, a conductive film for connecting the source region or the drain region to the polysilicon film filled in the trench is formed in an etched-off portion of the insulating layer of the SOI substrate.Type: GrantFiled: November 3, 1997Date of Patent: October 31, 2000Assignee: Kabushiki Kaisha ToshibaInventor: Yusuke Kohyama
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Patent number: 6130450Abstract: 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 is formed 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: GrantFiled: September 27, 1996Date of Patent: October 10, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Yusuke Kohyama, Takashi Ohsawa, Shizuo Sawada
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Patent number: 6104052Abstract: In a DRAM adopting a self-aligned contact structure, an opening portion of predetermined size is formed in advance in an insulation film which surrounds an on-field gate electrode formed on an element isolating insulation film. The on-field gate electrode contacts a gate contact through the opening portion. A contact hole for the gate contact can thus be formed in self-alignment as can be the contact holes for a bit-line contact and an active contact. Consequently, the contact hole for the gate contact reaching the on-field gate can be formed simultaneously with the contact holes for the bit-line contact and active contact, thereby greatly reducing the number of manufacturing steps.Type: GrantFiled: March 22, 1999Date of Patent: August 15, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Tohru Ozaki, Yusuke Kohyama
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Patent number: 6100130Abstract: 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: GrantFiled: April 4, 1997Date of Patent: August 8, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Junichiro Iba, Yusuke Kohyama
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Patent number: 6096631Abstract: The present invention provides a method of manufacturing a semiconductor device, including the steps of forming a first film on an entire surface of a substrate having a recessed portion, including a bottom surface and a side wall of the recessed portion, without completely filling the recessed portion, forming a second film on an entire surface of the first film such that the recessed portion, on the bottom surface and the side wall of which the first film is formed, is completely filled, and polishing the first and second films by a chemical-mechanical polishing method such that the substrate is exposed and the first and second films in the recessed portion remain.Type: GrantFiled: May 19, 1998Date of Patent: August 1, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Kenro Nakamura, Rempei Nakata, Yusuke Kohyama, Nobuo Hayasaka
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Patent number: 6094386Abstract: A semiconductor memory device includes 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: GrantFiled: August 10, 1999Date of Patent: July 25, 2000Assignee: Kabushiki Kaisha ToshibaInventor: Yusuke Kohyama
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Patent number: 6051859Abstract: 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.degree., 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) TiO.sub.3 thin film is formed on the Ru storage node electrode.Type: GrantFiled: January 16, 1998Date of Patent: April 18, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Keiji Hosotani, Yusuke Kohyama
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Patent number: 6020643Abstract: A semiconductor memory device comprises a semiconductor substrate, a first conducting layer formed above the main surface of the semiconductor substrate, a second conducting layer formed above the first conducting layer through a first insulating layer and connected to the first conducting layer through a first via-conductor formed in a first contact hole formed in the first insulating layer, and a third conducting layer formed beneath the second conducting layer through a second insulating layer and connected to the second conducting layer through a second via-conductor formed in a second contact hole formed in the second insulating layer, in which an angle formed by a tangent to an inner wall of the first contact hole and a normal to the first conducting layer at a portion of the first conducting layer at which the first contact hole is in contact with the first conducting layer, is larger than an angle formed by a tangent to an inner wall of the second contact hole and a normal to the third conducting layeType: GrantFiled: July 14, 1998Date of Patent: February 1, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Yoshiaki Fukuzumi, Yusuke Kohyama
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Patent number: 6015731Abstract: The first element separation oxide film consisting of a plurality of line-shaped portions parallel to the bit line is formed on the surface of the P-type silicon substrate. The first and second trenches are formed in that portion of the P-type silicon substrate which is located between an adjacent pair of line-shaped portions of the first element separation oxide film such that both sides of the trenches come in contact with the first element separation oxide film. A sheath plate capacitor is formed in each of the trenches. The second element separation oxide film having a thickness less than that of the first element separation oxide film is formed on that portion of the surface of the P-type silicon substrate which is located between the first and second trenches.Type: GrantFiled: September 4, 1997Date of Patent: January 18, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Yusuke Kohyama, Akira Sudo
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Patent number: RE36441Abstract: This invention discloses a semiconductor device comprising a semiconductor substrate, a first conducting layer formed on the surface of the semiconductor substrate, an insulating layer formed above the semiconductor substrate, the insulating layer having a contact hole reaching the first conducting layer to expose it, a second conducting layer formed on the insulating layer, the sidewall of the contact hole, and the first conducting layer, and an anti-oxidation layer formed on at least part of the surface of the second conducting layer.Type: GrantFiled: May 28, 1998Date of Patent: December 14, 1999Assignee: Kabushiki Kaisha ToshibaInventor: Yusuke Kohyama
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Patent number: RE36837Abstract: An insulation film is interposed between a first-level wiring layer and a second-level wiring layer. A contact hole is formed in the insulation film on the first-level wiring layer to electrically connect the first-level wiring layer and second-level wiring layer. The contact hole is larger than the width of the first-level wiring layer and second-level wiring layer. The second-level wiring layer is formed on a side wall and a bottom portion of the contact hole and electrically connected to the first-level wiring layer.Type: GrantFiled: June 19, 1998Date of Patent: August 29, 2000Assignee: Kabushiki Kaisha ToshibaInventor: Yusuke Kohyama