Patents by Inventor Mitsutaka Katada
Mitsutaka Katada 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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Patent number: 8410573Abstract: In a SOI structure semiconductor device using a SOI substrate, a lattice distortion layer is formed by implanting Ar ions into a silicon substrate as an active layer. The lattice distortion layer is capable of serving as a gettering site. The dose amount of Ar ions is adjusted in such a manner that tensile stress in the lattice distortion layer is equal to or greater than 11 MPa and equal to or less than 27 MPa. Thus, the lattice distortion layer can prevent occurrence of a leakage current while serving as the gettering site.Type: GrantFiled: October 20, 2008Date of Patent: April 2, 2013Assignees: DENSO CORPORATION, Shin-Etsu Handotai Co., Ltd.Inventors: Hiroshi Ohtsuki, Mitsutaka Katada, Nobuhiko Noto, Hiroshi Takeno, Kazuhiko Yoshida
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Patent number: 8035154Abstract: A semiconductor device includes a semiconductor substrate, a plurality of memory cells, a plurality of bit lines, and a plurality of source lines. The memory cells are located in the semiconductor substrate. Each of the memory cells includes a trench provided in the semiconductor substrate, an oxide layer disposed on a sidewall of the trench, a tunnel oxide layer disposed at a bottom portion of the trench, a floating gate disposed in the trench so as to be surrounded by the oxide layer and the tunnel oxide layer, and an erasing electrode disposed on an opposing side of the tunnel oxide layer from the floating gate. The bit lines and the source lines are alternately arranged on the memory cells in parallel with each other.Type: GrantFiled: November 4, 2008Date of Patent: October 11, 2011Assignee: DENSO CORPORATIONInventors: Takayoshi Naruse, Mitsutaka Katada, Tetsuo Fujii
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Publication number: 20100264510Abstract: In a SOI structure semiconductor device using a SOI substrate, a lattice distortion layer is formed by implanting Ar ions into a silicon substrate as an active layer. The lattice distortion layer is capable of serving as a gettering site. The dose amount of Ar ions is adjusted in such a manner that tensile stress in the lattice distortion layer is equal to or greater than 11 MPa and equal to or less than 27 MPa. Thus, the lattice distortion layer can prevent occurrence of a leakage current while serving as the gettering site.Type: ApplicationFiled: October 20, 2008Publication date: October 21, 2010Applicants: DENSO CORPORATION, Shin-Etsu Handotai Co., Ltd.Inventors: Hiroshi Ohtsuki, Mitsutaka Katada, Nobuhiko Noto, Hiroshi Takeno, Kazuhiko Yoshida
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Patent number: 7796442Abstract: A nonvolatile semiconductor memory device includes a semiconductor substrate having a source, a drain, and a channel region between the source and the drain. The channel region has a first end portion near the drain, a second end portion near the source, and a middle portion between the first and second end portions. The first and second end portions having approximately same width. The memory device is electrically erased by using a hot carrier generated in the first end portion due to avalanche breakdown. The channel region includes a first channel extending from the drain and a second channel adjacent to the first channel. An impurity concentration of the second channel is higher than that of the first channel. An interface between the first and second channels is located in the middle portion between the first and second end portions.Type: GrantFiled: March 31, 2008Date of Patent: September 14, 2010Assignee: DENSO CORPORATIONInventors: Mitsutaka Katada, Yukiaki Yogo, Akira Tai, Yukihiko Watanabe
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Patent number: 7642653Abstract: A semiconductor device includes a substrate, an element formed in the substrate, an insulation film formed on the substrate, wiring layers, and an electrode pad. The wiring layers are multilayered and electrically coupled to the element through the insulation film. The electrode pad is electrically coupled to a top wiring layer of the wiring layers. The top wiring layer is configured to be a top wiring-electrode layer that doubles as an electrode layer disposed under the electrode pad. The electrode layer of the top wiring-electrode layer is disposed directly above the element. The electrode pad and the electrode layer are multilayered to form a pad structure.Type: GrantFiled: October 23, 2007Date of Patent: January 5, 2010Assignee: DENSO CORPORATIONInventors: Takeshi Kuzuhara, Atsushi Komura, Mitsutaka Katada, Takayoshi Naruse
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Publication number: 20090114974Abstract: A semiconductor device includes a semiconductor substrate, a plurality of memory cells, a plurality of bit lines, and a plurality of source lines. The memory cells are located in the semiconductor substrate. Each of the memory cells includes a trench provided in the semiconductor substrate, an oxide layer disposed on a sidewall of the trench, a tunnel oxide layer disposed at a bottom portion of the trench, a floating gate disposed in the trench so as to be surrounded by the oxide layer and the tunnel oxide layer, and an erasing electrode disposed on an opposing side of the tunnel oxide layer from the floating gate. The bit lines and the source lines are alternately arranged on the memory cells in parallel with each other.Type: ApplicationFiled: November 4, 2008Publication date: May 7, 2009Applicant: DENSO CORPORATIONInventors: Takayoshi Naruse, Mitsutaka Katada, Tetsuo Fujii
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Publication number: 20080258304Abstract: A semiconductor device includes: a substrate; and wiring layers on the substrate. Each wiring layer includes: an interlayer insulation film having a wiring groove with a via hole; a copper wiring in the groove and the hole; an barrier metal layer between an inner wall of the groove with the hole and the copper wiring; and an upper barrier metal layer on the interlayer insulation film and covering an upper surface of the copper wiring. The barrier metal layer prevents a copper component in the copper wiring from diffusing into the interlayer insulation film. The copper wiring of an upper layer is electrically coupled with the copper wiring of a lower layer. The upper barrier metal layer of the lower layer prevents a copper component in the copper wiring of the lower layer from diffusing into the interlayer insulation film of the upper layer.Type: ApplicationFiled: April 22, 2008Publication date: October 23, 2008Applicant: DENSO CORPORATIONInventors: Atsushi KOMURA, Takeshi KUZUHARA, Takayoshi NARUSE, Mitsutaka KATADA
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Publication number: 20080239817Abstract: A nonvolatile semiconductor memory device includes a semiconductor substrate having a source, a drain, and a channel region between the source and the drain. The channel region has a first end portion near the drain, a second end portion near the source, and a middle portion between the first and second end portions. The first and second end portions having approximately same width. The memory device is electrically erased by using a hot carrier generated in the first end portion due to avalanche breakdown. The channel region includes a first channel extending from the drain and a second channel adjacent to the first channel. An impurity concentration of the second channel is higher than that of the first channel. An interface between the first and second channels is located in the middle portion between the first and second end portions.Type: ApplicationFiled: March 31, 2008Publication date: October 2, 2008Applicant: DENSO CORPORATIONInventors: Mitsutaka Katada, Yukiaki Yogo, Akira Tai, Yukihiko Watanabe
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Publication number: 20080105947Abstract: A semiconductor device includes a substrate, an element formed in the substrate, an insulation film formed on the substrate, wiring layers, and an electrode pad. The wiring layers are multilayered and electrically coupled to the element through the insulation film. The electrode pad is electrically coupled to a top wiring layer of the wiring layers. The top wiring layer is configured to be a top wiring-electrode layer that doubles as an electrode layer disposed under the electrode pad. The electrode layer of the top wiring-electrode layer is disposed directly above the element. The electrode pad and the electrode layer are multilayered to form a pad structure.Type: ApplicationFiled: October 23, 2007Publication date: May 8, 2008Applicant: DENSO CORPORATIONInventors: Takeshi Kuzuhara, Atsushi Komura, Mitsutaka Katada, Takayoshi Naruse
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Patent number: 6914288Abstract: A memory transistor of an EEPROM has a floating gate electrode of a shape such that it covers the entirety of a tunnel film and a channel region and does not cover a region between the channel region and an embedded layer. And, a control gate electrode is formed on an interlayer insulating film on the floating gate electrode into a shape such that it is wider than the floating gate electrode above the tunnel film, and is narrower than the floating gate electrode above the channel region.Type: GrantFiled: September 12, 2003Date of Patent: July 5, 2005Assignee: Denso CorporationInventors: Hiroyasu Itou, Mitsutaka Katada, Hidetoshi Muramoto
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Publication number: 20040070022Abstract: A memory transistor of an EEPROM has a floating gate electrode of a shape such that it covers the entirety of a tunnel film and a channel region and does not cover a region between the channel region and an embedded layer. And, a control gate electrode is formed on an interlayer insulating film on the floating gate electrode into a shape such that it is wider than the floating gate electrode above the tunnel film, and is narrower than the floating gate electrode above the channel region.Type: ApplicationFiled: September 12, 2003Publication date: April 15, 2004Inventors: Hiroyasu Itou, Mitsutaka Katada, Hidetoshi Muramoto
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Patent number: 6339557Abstract: In a nonvolatile semiconductor memory, a floating gate electrode is disposed above a silicon substrate between source and drain regions, through a tunnel film, and a control gate electrode is disposed above the floating gate electrode through an insulating film. The substrate is grounded and at least two negative voltages are respectively applied to the control gate electrode, so that a voltage is applied to the tunnel film. In these cases, charge retention properties are evaluated. The voltages applied to the control gate electrode are controlled so that the voltage applied to the tunnel film does not exceed a voltage applied to the tunnel film during a memory operation. A charge retention property when no voltage is applied across the control gate electrode and the substrate, i.e., when no voltage is externally applied to the tunnel film, is estimated by the charge retention properties when the two voltages are applied to the control gate electrode.Type: GrantFiled: May 31, 2000Date of Patent: January 15, 2002Assignee: Denso CorporationInventors: Tsutomu Kawaguchi, Shigemitsu Fukatsu, Mitsutaka Katada
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Patent number: 6337249Abstract: A semiconductor device having an enhancement-type MOS structure which can prevent large leakage current is disclosed. A high-concentration region for threshold-value regulation use formed in a channel region below a gate electrode in an enhancement-type transistor is caused to be contiguous with a source region and not contiguous with a drain region. Herein, the distance between the high-concentration region and the drain region is set so as to preclude the depletion layer extending from the drain region side from reaching the high-concentration region. Therefore, the electrical field in the depletion layer does not become the critical field which causes avalanche or Zener breakdown, and so leakage current can be caused to be reduced.Type: GrantFiled: November 20, 2000Date of Patent: January 8, 2002Assignee: NipponDenso Co., Ltd.Inventors: Hiroyuki Yamane, Yasushi Higuchi, Mitsutaka Katada, Noriyuki Iwamori, Tsutomu Kawaguchi, Takeshi Kuzuhara
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Patent number: 6236085Abstract: A semiconductor memory device comprising a source and a drain formed in a P-type semiconductor substrate and a floating gate and a control gate constituting a two-layer gate. Electric-field moderating layer is provided in the P-type semiconductor substrate to contact with a side face of the drain. P-type region is formed in contact with channel region side surface and bottom surface of the electric-field moderating layer. P-type region lower part of the P-type region in contact with the bottom surface of the electric-field moderating layer is given a lower impurity concentration than P-type region side part formed at the channel region side of the electric-field moderating layer. By this means it is possible to increase the writing speed of the semiconductor memory device while suppressing delay in the switching speed during reading operation.Type: GrantFiled: November 10, 1997Date of Patent: May 22, 2001Assignee: Denso CorporationInventors: Tsutomu Kawaguchi, Mitsutaka Katada
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Patent number: 5753556Abstract: A CMIS transistor suitable for device miniaturization, elimination of degradation of operational characteristics by hot carrier effect, and elimination of decrease of threshold voltage caused by short channel effect, includes a laterally spreading N-type diffusion region having an impurity concentration level higher than P-type and N-type wells but lower than source and drain regions, such that the N-type diffusion region extends laterally into a part located immediately below an edge of an insulating gate and has a depth smaller than a depth of the source and drain regions. The device is thereby capable of increasing the width of depletion layer at the bottom of the source and drain regions while maintaining effectiveness as a punch-thorough stopper. Thereby, the junction capacitance at the source and drain regions is reduced and the operational speed of the device improved in the P-channel transistor part in the device.Type: GrantFiled: March 29, 1996Date of Patent: May 19, 1998Assignee: Nippondenso Co., Ltd.Inventors: Mitsutaka Katada, Hidetoshi Muramoto, Seiji Fujino, Tadashi Hattori, Katsunori Abe
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Patent number: 5736770Abstract: A semiconductor device comprising: a semiconductor substrate; a diffused region extending from the surface and to the inside of the semiconductor substrate; a first insulating layer formed on the semiconductor substrate and having a contact hole located through which the diffused region is exposed; a first conductor layer formed on a portion of the first insulating layer and connected so the diffused region through the first contact hole; and an insulator section made of an oxide of the substance of the first conductor layer and formed on another portion of the first insulating layer to surround the first conductor layer.Type: GrantFiled: May 24, 1994Date of Patent: April 7, 1998Assignee: Nippondenso Co., Ltd.Inventors: Akiyoshi Asai, Nobuyuki Ohya, Mitsutaka Katada
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Patent number: 5675167Abstract: A semiconductor device having an enhancement-type MOS structure which can prevent large leakage current is disclosed. A high-concentration region for threshold-value regulation use formed in a channel region below a gate electrode in an enhancement-type transistor is caused to be contiguous with a source region and not contiguous with a drain region. Herein, the distance between the high-concentration region and the drain region is set so as to preclude the depletion layer extending from the drain region side from reaching the high-concentration region. Therefore, the electrical field in the depletion layer does not become the critical field which causes avalanche or Zener breakdown, and so leakage current can be caused to be reduced.Type: GrantFiled: November 24, 1995Date of Patent: October 7, 1997Assignee: Nippondenso Co., Ltd.Inventors: Hiroyuki Yamane, Yasushi Higuchi, Mitsutaka Katada, Noriyuki Iwamori, Tsutomu Kawaguchi, Takeshi Kuzuhara
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Patent number: 5532176Abstract: A CMIS transistor suitable for device miniaturization, elimination of degradation of operational characteristics by hot carrier effect, and elimination of decrease of threshold voltage caused by short channel effect, includes a laterally spreading N-type diffusion region having an impurity concentration level higher than P-type and N-type wells but lower than source and drain regions, such that the N-type diffusion region extends laterally into a part located immediately below an edge of an insulating gate and has a depth smaller than a depth of the source and drain regions. The device is thereby capable of increasing the width of depletion layer at the bottom of the source and drain regions while maintaining effectiveness as a punch-thorough stopper. Thereby, the junction capacitance at the source and drain regions is reduced and the operational speed of the device improved in the P-channel transistor part in the device.Type: GrantFiled: July 26, 1994Date of Patent: July 2, 1996Assignee: Nippondenso Co., Ltd.Inventors: Mitsutaka Katada, Hidetoshi Muramoto, Seizi Fuzino, Tadashi Hattori, Katsunori Abe
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Patent number: 5383993Abstract: In a method of bonding semiconductor substrates, a plurality of the semiconductor substrates are first prepared. Surfaces of the semiconductor substrates are mirror-polished. The mirror-polished surface of at least one of the semiconductor substrates is then provided with a hydrophilic property in such a way that an oxide layer is formed on the mirror-polished surface by exposing the mirror-polished surface to an atmosphere of at least one of an oxygen ion and an oxygen radical. A water molecule is then adhered to the mirror-polished surface. The semiconductor substrates then contact with each other through the mirror-polished surface. The contacted semiconductor substrates are then heated. According to such a method of bonding, the semiconductor substrates are strongly bonded to each other with hardly an unbonded region even if the semiconductor substrates are heated at a low temperature.Type: GrantFiled: September 10, 1993Date of Patent: January 24, 1995Assignee: Nippon Soken Inc.Inventors: Mitsutaka Katada, Kazuhiro Tsuruta, Seiji Fujino, Michitoshi Onoda
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Patent number: 5334870Abstract: A CMIS transistor suitable for device miniaturization, elimination of degradation of operational characteristics by hot carrier effect, and elimination of decrease of threshold voltage caused by short channel effect, includes a laterally spreading N-type diffusion region having an impurity concentration level higher than P-type and N-type wells but lower than source and drain regions, such that the N-type diffusion region extends laterally into a part located immediately below an edge of an insulating gate and has a depth smaller than a depth of the source and drain regions. The device is thereby capable of increasing the width of depletion layer at the bottom of the source and drain regions while maintaining effectiveness as a punch-through stopper. Thereby, the junction capacitance at the source and drain regions is reduced and the operational speed of the device improved in the P-channel transistor part in the device.Type: GrantFiled: April 16, 1993Date of Patent: August 2, 1994Assignee: Nippondenso Co. Ltd.Inventors: Mitsutaka Katada, Hidetoshi Muramoto, Seizi Fuzino, Tadashi Hattori, Katsunori Abe