Patents by Inventor Kiyonori Oyu
Kiyonori Oyu 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: 20100314671Abstract: A semiconductor device includes a semiconductor substrate, and an extending semiconductor portion that extends vertically from the semiconductor substrate. The extending semiconductor portion has a side surface which comprises four main surfaces of {100} face and four sub-surfaces of {110} face. The four sub-surfaces are smaller in area than the four main surfaces.Type: ApplicationFiled: June 9, 2010Publication date: December 16, 2010Applicant: ELPIDA MEMORY, INC.Inventors: Kiyonori Oyu, Kazuhiro Nojima
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Patent number: 7846826Abstract: A gate dielectric film, a poly-silicon film, a film of a refractory metal such as tungsten, and a gate cap dielectric film are sequentially laminated on a semiconductor substrate. The gate cap dielectric film and the refractory metal film are selectively removed by etching. Thereafter, a double protection film including a silicon nitride film and a silicon oxide film is formed on side surfaces of the gate cap dielectric film, the refractory metal film, and the poly-silicon film. The poly-silicon film is etched using the double protection film as a mask. Thereafter, the semiconductor substrate is light oxidized to form a silicon oxide film on side surfaces of the poly-silicon film. Accordingly, a junction leakage of a MOSFET having a gate electrode of a poly-metal structure, particularly, a memory cell transistor of a DRAM, can be further reduced.Type: GrantFiled: October 7, 2008Date of Patent: December 7, 2010Assignee: Elpida Memory Inc.Inventors: Kiyonori Oyu, Kensuke Okonogi
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Publication number: 20100237406Abstract: A semiconductor memory device includes a silicon pillar that is provided with a first channel formed in a first area on one side among two sides that are perpendicular to an extension direction of a bit line, a second channel formed in a second area on the other side among the two sides that is not overlapped with the first area in the extension direction of the bit line, and of which the other area on the two sides is an insulating oxide film formed by being oxidized, and two word lines that cover the one side and the other side of the silicon pillar via a gate insulating film, respectively. The first channel and the second channel are separated from each other in an insulating manner by the insulating oxide film.Type: ApplicationFiled: March 16, 2010Publication date: September 23, 2010Applicant: ELPIDA MEMORY INC.Inventor: KIYONORI OYU
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Patent number: 7696609Abstract: The present invention provides a semiconductor chip that provides a semiconductor device with high reliability and low leak current, and a method of manufacturing such a semiconductor chip, and more specifically, provides a semiconductor chip comprising memory portions and a peripheral circuit portion, where the memory portions and the peripheral circuit portion are formed in a main surface portion of the semiconductor chip, a thickness of the sections of the semiconductor chip passing through the main surface portion in which the memory portions are formed is larger than a thickness of sections of the semiconductor chip passing through the main surface portion in which the peripheral circuit portion is formed, and a method of manufacturing such a semiconductor chip.Type: GrantFiled: December 1, 2005Date of Patent: April 13, 2010Assignee: Elpida Memory, Inc.Inventor: Kiyonori Oyu
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Publication number: 20100078712Abstract: A semiconductor device includes a first semiconductor pillar, a first gate insulating film, a gate electrode, and a first contact. The first semiconductor pillar extends upwardly from a semiconductor substrate. The first gate insulating film covers side surfaces of the first semiconductor pillar. The gate electrode covers the first gate insulating film. The first gate insulating film insulates the gate electrode from the first semiconductor pillar. The first contact partially overlaps, in plane view, the first semiconductor pillar and the gate electrode. The first contact includes a silicon layer having a top level which is higher than a top level of the gate electrode.Type: ApplicationFiled: September 17, 2009Publication date: April 1, 2010Applicant: ELPIDA MEMORY, INC.Inventors: Yoshinori IKEBUCHI, Kiyonori OYU, Yoshihiro TAKAISHI
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Patent number: 7687849Abstract: Disclosed is a technique for reducing the leak current by reducing contamination of metal composing a polymetal gate of a MISFET. Of a polycrystalline silicon film, a WN film, a W film, and a cap insulating film formed on a gate insulating film on a p-type well (semiconductor substrate), the cap insulating film, the W film, and the WN film are etched and the over-etching of the polycrystalline silicon film below them is performed. Then, a sidewall film is formed on sidewalls of these films. Thereafter, after etching the polycrystalline silicon film with using the sidewall film as a mask, a thermal treatment is performed in an oxidation atmosphere, by which a light oxide film is formed on the sidewall of the polycrystalline silicon film. As a result, the contamination on the gate insulating film due to the W and the W oxide can be reduced, and also, the diffusion of these materials into the semiconductor substrate (p-type well) and the resultant increase of the leak current can be prevented.Type: GrantFiled: May 29, 2008Date of Patent: March 30, 2010Assignee: Elpida Memory, Inc.Inventors: Hiroshi Kujirai, Kousuke Okuyama, Kazuhiro Hata, Kiyonori Oyu, Ryo Nagai, Hiroyuki Uchiyama, Takahiro Kumauchi, Teruhisa Ichise
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Patent number: 7687351Abstract: A semiconductor device includes: a semiconductor substrate; multiple active regions of a first conductive type isolated from one another by shallow-trench isolation regions provided on one surface of the semiconductor substrate; multiple silicon pillars including channel silicon pillars formed in the active regions; multiple first semiconductor regions of a second conductive type that are respectively formed on bottom ends of the silicon pillars and to be sources or drains; multiple second semiconductor regions of the second conductive type that are formed on top ends of the silicon pillars and to be sources or drains; multiple gate insulating films surrounding the silicon pillars; and multiple gate electrodes surrounding the gate insulating films. At least one of the channel silicon pillars has a height different from that of another one of the channel silicon pillars.Type: GrantFiled: December 4, 2008Date of Patent: March 30, 2010Assignee: Elpida Memory, Inc.Inventor: Kiyonori Oyu
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Publication number: 20100072552Abstract: A field effect transistor includes an active region provided in a projecting part on a surface of a semiconductor substrate, the projecting part extending in a fixed direction parallel to the surface, and a gate electrode provided on a sidewall of the projecting part along the fixed direction with a gate insulating films interposed.Type: ApplicationFiled: September 17, 2009Publication date: March 25, 2010Applicant: Elpida Memory,IncInventors: Hideo SUNAMI, Atsushi Sugimura, Kiyoshi Okuyama, Kiyonori Oyu, Hideharu Miyake
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Patent number: 7682895Abstract: A method of manufacturing a semiconductor device includes: (A) a wafer process; and (B) a bias application process after the wafer process. The wafer process includes: (a) forming a n-type well in a p-type semiconductor substrate; (b) forming a p-type well in the n-type well; and (c) forming a transistor on the p-type well, the transistor having a n-type source/drain diffusion layer. In the bias application process, a forward bias is applied between the p-type well and the n-type well to move heavy metal ions.Type: GrantFiled: February 26, 2007Date of Patent: March 23, 2010Assignee: Elpida Memory, Inc.Inventor: Kiyonori Oyu
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Patent number: 7670911Abstract: A method for manufacturing a vertical MOS transistor comprising forming a protrusion-like region, forming a silicon oxide film on an exposed surface of the protrusion-like region and a surface of the silicon semiconductor substrate, increasing a film thickness of at least the silicon oxide film on the silicon semiconductor substrate by thermal oxidation to form a first insulating film, forming a lower impurity diffusion region, removing the silicon oxide film to expose a silicon side of the protrusion-like region, thermally oxidizing the silicon side to form a second insulating film having a thinner film thickness than a film thickness of the first insulating film, forming a gate electrode over a side of the protrusion-like region, and forming an upper impurity diffusion region.Type: GrantFiled: July 31, 2008Date of Patent: March 2, 2010Assignee: Elpida Memory, Inc.Inventor: Kiyonori Oyu
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Patent number: 7666761Abstract: In manufacturing a semiconductor device, the first gettering layer is formed on the backside of a wafer, and the second gettering layers are then formed on the backside and side surfaces of a chip, allowing these gettering layers to serve as trapping sites against metallic contamination that generated after backside grinding in assembly processes.Type: GrantFiled: March 1, 2007Date of Patent: February 23, 2010Assignee: Elpida Memory, Inc.Inventors: Kiyonori Oyu, Kensuke Okonogi, Hirotaka Kobayashi, Koji Hamada
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Patent number: 7649256Abstract: A semiconductor chip having a thickness of 130 micrometers or less includes a mechanically ground bottom surface corresponding to a central circuit area, and a polished bottom surface corresponding to a peripheral scribe area. The mechanically ground bottom surface prevents heavy metals attached onto the bottom surface of the wafer from diffusing toward the source/drain regions of the semiconductor substrate and thereby from degrading the transistor characteristics.Type: GrantFiled: July 8, 2005Date of Patent: January 19, 2010Assignee: Elpida Memory, Inc.Inventors: Hiroshi Kujirai, Kiyonori Oyu
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Patent number: 7632696Abstract: A semiconductor chip including a semiconductor substrate provided with a semiconductor device region and a porous single crystal layer, where the semiconductor device region is formed on the main surface portion of the semiconductor substrate, and the porous single crystal layer is formed in an inner region on the backside of the semiconductor substrate, and is comprised of erosion holes extending continuously from the backside of the semiconductor substrate in an inward direction of the semiconductor substrate, oxide films formed on inner surfaces of the erosion holes, and a single crystal portion.Type: GrantFiled: March 10, 2006Date of Patent: December 15, 2009Assignee: Elpida Memory, Inc.Inventors: Kiyonori Oyu, Koji Hamada, Kensuke Okonogi, Hideharu Miyake, Yasushi Kozuki, Masaharu Watanabe
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Publication number: 20090230530Abstract: A back side of the silicon semiconductor substrate is roughly ground and is finishing-ground by using a whetstone having a copper content of less than 1 ppm, the back side being an opposite side of a side on which the semiconductor element is formed. The back side of the silicon semiconductor substrate is cleaned by the silicon chemical etching. A part up to depth of 3 nm from the back side of the silicon semiconductor substrate comprises copper of 1×109/cm2 or less.Type: ApplicationFiled: November 6, 2008Publication date: September 17, 2009Applicant: Elpida Memory, Inc.Inventors: Kiyonori OYU, Kazuyuki Hozawa
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Publication number: 20090209079Abstract: A method for manufacturing a semiconductor device includes forming a diffusion layer on a silicon substrate by doping an impurity of a first conductivity type into a region of a second conductivity type opposite to the first conductivity type and performing a heat treatment; implanting nitrogen or fluorine ions into the diffusion layer; and irradiating carbon dioxide gas laser light to the diffusion layer after the implanting.Type: ApplicationFiled: January 21, 2009Publication date: August 20, 2009Applicant: ELPIDA MEMORY, INC.Inventors: Kiyonori OYU, Kensuke Okonogi, Akio Shima
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Publication number: 20090148992Abstract: A semiconductor device includes: a semiconductor substrate; multiple active regions of a first conductive type isolated from one another by shallow-trench isolation regions provided on one surface of the semiconductor substrate; multiple silicon pillars including channel silicon pillars formed in the active regions; multiple first semiconductor regions of a second conductive type that are respectively formed on bottom ends of the silicon pillars and to be sources or drains; multiple second semiconductor regions of the second conductive type that are formed on top ends of the silicon pillars and to be sources or drains; multiple gate insulating films surrounding the silicon pillars; and multiple gate electrodes surrounding the gate insulating films. At least one of the channel silicon pillars has a height different from that of another one of the channel silicon pillars.Type: ApplicationFiled: December 4, 2008Publication date: June 11, 2009Applicant: ELPIDA MEMORY, INC.Inventor: Kiyonori OYU
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Publication number: 20090085098Abstract: A semiconductor device includes: a plurality of vertical MOS transistors sharing a gate electrode (2) of a first conductivity type; first semiconductor pillars (3, 4 and 5) with a gate insulating film (18) formed therearound, across the gate insulating film (18) the vertical MOS transistors facing the gate electrode; and a second semiconductor pillar (8) being of the first conductivity type which is the same as the conductivity type of the gate electrode and being in contact with the gate electrode at a portion thereof from which at least a part of the gate insulating film is removed, wherein potential supply (6) to the shared gate electrode (2) is effected through the second semiconductor pillar (8).Type: ApplicationFiled: September 26, 2008Publication date: April 2, 2009Applicant: Elpida Memory, IncInventor: Kiyonori Oyu
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Publication number: 20090065856Abstract: In a vertical MOS transistor in which a semiconductor pillar is formed by etching a semiconductor substrate in a portion surrounded by an isolation film, the semiconductor pillar is covered with a gate insulating film and a gate electrode to be made a channel part, and diffusion layers to be a source and a drain are included on a top and a bottom of the channel part, electrode 14 which controls potential of a gate electrode material is formed in gate electrode material 8 formed on a side surface of isolation film 2, in order to eliminate a parasitic MOS operation by the gate electrode material remaining on the side surface of the isolation film.Type: ApplicationFiled: September 2, 2008Publication date: March 12, 2009Applicant: ELPIDA MEMORY, INC.Inventors: Kiyonori Oyu, Yoshihiro Takaishi, Yu Kosuge
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Publication number: 20090042347Abstract: A method for manufacturing a vertical MOS transistor comprising forming a protrusion-like region, forming a silicon oxide film on an exposed surface of the protrusion-like region and a surface of the silicon semiconductor substrate, increasing a film thickness of at least the silicon oxide film on the silicon semiconductor substrate by thermal oxidation to form a first insulating film, forming a lower impurity diffusion region, removing the silicon oxide film to expose a silicon side of the protrusion-like region, thermally oxidizing the silicon side to form a second insulating film having a thinner film thickness than a film thickness of the first insulating film, forming a gate electrode over a side of the protrusion-like region, and forming an upper impurity diffusion region.Type: ApplicationFiled: July 31, 2008Publication date: February 12, 2009Applicant: ELPIDA MEMORY, INCInventor: Kiyonori OYU
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Publication number: 20090042380Abstract: A gate dielectric film, a poly-silicon film, a film of a refractory metal such as tungsten, and a gate cap dielectric film are sequentially laminated on a semiconductor substrate. The gate cap dielectric film and the refractory metal film are selectively removed by etching. Thereafter, a double protection film including a silicon nitride film and a silicon oxide film is formed on side surfaces of the gate cap dielectric film, the refractory metal film, and the poly-silicon film. The poly-silicon film is etched using the double protection film as a mask. Thereafter, the semiconductor substrate is light oxidized to form a silicon oxide film on side surfaces of the poly-silicon film. Accordingly, a junction leakage of a MOSFET having a gate electrode of a poly-metal structure, particularly, a memory cell transistor of a DRAM, can be further reduced.Type: ApplicationFiled: October 7, 2008Publication date: February 12, 2009Applicant: Elpida Memory, Inc.Inventors: Kiyonori OYU, Kensuke OKONOGI