Patents by Inventor Keizo Kawakita

Keizo Kawakita 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).

  • Publication number: 20030132479
    Abstract: In order to improve connection reliability of a feeding interconnection connected to an electrode of each of the information storage capacitive elements of a DRAM, the formation of a through hole for connecting the information storage capacitive element formed over each memory cell selection MISFET and a feeding interconnection is performed in a process different from that for the formation of a through hole for connecting an interconnection of a second wiring layer in a peripheral circuit, which is formed over the information storage capacitive element and an interconnection corresponding to a first wiring layer.
    Type: Application
    Filed: January 3, 2003
    Publication date: July 17, 2003
    Inventors: Yoshitaka Nakamura, Masayoshi Hirasawa, Isamu Asano, Tsuyoshi Tamaru, Satoru Yamada, Keizo Kawakita, Toshihiro Sekiguchi, Yoshitaka Tadaki, Takuya Fukuda
  • Publication number: 20030064578
    Abstract: [Object] To prevent Al wiring formed on a via-hole in which a CVD-TiN film is embedded from corroding.
    Type: Application
    Filed: November 5, 2002
    Publication date: April 3, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Yoshitaka Nakamura, Tsuyoshi Tamaru, Naoki Fukuda, Hidekazu Goto, Isamu Asano, Hideo Aoki, Keizo Kawakita, Satoru Yamada, Katsuhiko Tanaka, Hiroshi Sakuma, Masayoshi Hirasawa
  • Publication number: 20030001214
    Abstract: An active region (L) with a metal insulator semiconductor field effect transistor (MISFET) (Qs) formed therein for selection of a DRAM memory cell, which makes up a memory cell of the DRAM, is arranged to have an island-like pattern that linearly extends in an X direction on one principal surface of a semiconductor substrate (1). The memory-cell selection MISFET (Qs) has an insulated gate electrode (7) (word line WL) that extends along a Y direction on the principal surface of the semiconductor substrate (1) with the same width kept along the length thereof, which gate electrode is arranged to oppose another gate electrode (7) (word line WL) adjacent thereto at a prespecified distance or pitch that is narrower than said width.
    Type: Application
    Filed: August 27, 2002
    Publication date: January 2, 2003
    Inventors: Makoto Yoshida, Takahiro Kumauchi, Yoshitaka Tadaki, Isamu Asano, Norio Hasegawa, Keizo Kawakita
  • Publication number: 20020192905
    Abstract: A DRAM has, in one embodiment, a plurality of word lines each having its upper and side surfaces covered with a first insulating film, a plurality of bit lines each being provided so as to be insulated from and transverse to the word lines and being covered with a second insulating film, and a plurality of memory cells each provided at an intersection between one word line and one bit line and including a capacitor and a memory cell selection transistor, in which contact holes for connection between semiconductor regions and capacitors and between semiconductor regions and bit lines are formed in self-alignment and the second insulating film is made of a material having a permittivity smaller than that of the first insulating film.
    Type: Application
    Filed: August 23, 2002
    Publication date: December 19, 2002
    Inventors: Toshihiro Sekiguchi, Yoshitaka Tadaki, Keizo Kawakita, Hideo Aoki, Toshikazu Kumai, Kazuhiko Saito, Michio Nishimura, Michio Tanaka, Katsuo Yuhara, Shinya Nishio, Toshiyuki Kaeriyama, Songsu Cho
  • Patent number: 6492730
    Abstract: The semiconductor device is formed according to the following steps. A TiN film 71 and a W film 72 are deposited on a silicon oxide film 64 including the inside of a via-hole 66 by the CVD method and thereafter, the W film 72 and TiN film 71 on the silicon oxide film 64 are etched back to leave only the inside of the via-hole 66 and form a plug 73. Then, a TiN film 74, Al-alloy film 75, and Ti film 76 are deposited on the silicon oxide film 64 including the surface of the plug 73 by the sputtering method and thereafter, the Ti film 76, Al-alloy film 75, and TiN film 74 are patterned to form second-layer wirings 77 and 78.
    Type: Grant
    Filed: January 11, 2000
    Date of Patent: December 10, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Yoshitaka Nakamura, Tsuyoshi Tamaru, Naoki Fukuda, Hidekazu Goto, Isamu Asano, Hideo Aoki, Keizo Kawakita, Satoru Yamada, Katsuhiko Tanaka, Hiroshi Sakuma, Masayoshi Hirasawa
  • Publication number: 20020182798
    Abstract: In a DRAM having a capacitor-over-bitline structure in which the capacitive insulating film of an information storing capacitive element C is formed of a high dielectric material such as Ta2O5 (tantalum oxide) film 46, the portions of bit lines BL and first-layer interconnect lines 23 to 26 of a peripheral circuit which are in contact with at least an underlying silicon oxide film 28 are formed of a W film, the bit lines BL and the interconnect lines 23 to 26 being arranged below the information storing capacitive element C, whereby the adhesion at the interface between the bit lines BL and the interconnect lines 23 to 26 and the silicon oxide film is improved in terms of high-temperature heat treatment to be performed when the capacitive insulating film is being formed.
    Type: Application
    Filed: May 31, 2002
    Publication date: December 5, 2002
    Inventors: Masayoshi Saito, Yoshitaka Nakamura, Hidekazu Goto, Keizo Kawakita, Satoru Yamada, Toshihiro Sekiguchi, Isamu Asano, Yoshitaka Tadaki, Takuya Fukuda, Masayuki Suzuki, Tsuyoshi Tamaru, Naoki Fukuda, Hideo Aoki, Masayoshi Hirasawa
  • Patent number: 6483136
    Abstract: An active region (L) with a metal insulator semiconductor field effect transistor (MISFET) (Qs) formed therein for selection of a DRAM memory cell, which makes up a memory cell of the DRAM, is arranged to have an island-like pattern that linearly extends in an X direction on one principal surface of a semiconductor substrate (1). The memory-cell selection MISFET (Qs) has an insulated gate electrode (7) (word line WL) that extends along a Y direction on the principal surface of the semiconductor substrate (1) with the same width kept along the length thereof, which gate electrode is arranged to oppose another gate electrode (7) (word line WL) adjacent thereto at a prespecified distance or pitch that is narrower than said width.
    Type: Grant
    Filed: April 14, 2000
    Date of Patent: November 19, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Makoto Yoshida, Takahiro Kumauchi, Yoshitaka Tadaki, Isamu Asano, Norio Hasegawa, Keizo Kawakita
  • Patent number: 6399438
    Abstract: In a DRAM having a capacitor-over-bitline structure in which the capacitive insulating film of an information storing capacitive element C is formed of a high dielectric material such as Ta2O5 (tantalum oxide) film 46, the portions of bit lines BL and first-layer interconnect lines 23 to 26 of a peripheral circuit which are in contact with at least an underlying silicon oxide film 28 are formed of a W film, the bit lines BL and the interconnect lines 23 to 26 being arranged below the information storing capacitive element C, whereby the adhesion at the interface between the bit lines BL and the interconnect lines 23 to 26 and the silicon oxide film is improved in terms of high-temperature heat treatment to be performed when the capacitive insulating film is being formed.
    Type: Grant
    Filed: April 9, 2001
    Date of Patent: June 4, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Masayoshi Saito, Yoshitaka Nakamura, Hidekazu Goto, Keizo Kawakita, Satoru Yamada, Toshihiro Sekiguchi, Isamu Asano, Yoshitaka Tadaki, Takuya Fukuda, Masayuki Suzuki, Tsuyoshi Tamaru, Naoki Fukuda, Hideo Aoki, Masayoshi Hirasawa
  • Patent number: 6372554
    Abstract: A pattern of more than one conductive layer overlying a fuse formed in a TEG region is subject to OR processing; further, a combined or “synthetic” pattern with an opening pattern of one or more testing pads connected to said fuse added thereto is copied by transfer printing techniques to a photosensitive resin layer that is coated on the surface of a semiconductor wafer, thereby forcing the resin layer to reside only in a selected area of a scribe region, to which area the synthetic pattern has been transferred.
    Type: Grant
    Filed: September 7, 1999
    Date of Patent: April 16, 2002
    Assignees: Hitachi, Ltd., Hitachi ULSI Systems Co., Ltd.
    Inventors: Keizo Kawakita, Kazuhiko Kajigaya, Seiji Narui, Kiyoshi Nakai, Kazunari Suzuki, Hideaki Tsugane, Fumiyoshi Sato
  • Publication number: 20010028082
    Abstract: In order to improve connection reliability of a feeding interconnection connected to an electrode of each of the information storage capacitive elements of a DRAM, the formation of a through hole for connecting the information storage capacitive element formed over each memory cell selection MISFET and a feeding interconnection is performed in a process different from that for the formation of a through hole for connecting an interconnection of a second wiring layer in a peripheral circuit, which is formed over the information storage capacitive element and an interconnection corresponding to a first wiring layer.
    Type: Application
    Filed: June 15, 2001
    Publication date: October 11, 2001
    Inventors: Yoshitaka Nakamura, Masayoshi Hirasawa, Isamu Asano, Tsuyoshi Tamaru, Satoru Yamada, Keizo Kawakita, Toshihiro Sekiguchi, Yoshitaka Tadaki, Takuya Fukuda
  • Publication number: 20010023099
    Abstract: In a DRAM having a capacitor-over-bitline structure in which the capacitive insulating film of an information storing capacitive element C is formed of a high dielectric material such as Ta2O5 (tantalum oxide) film 46, the portions of bit lines BL and first-layer interconnect lines 23 to 26 of a peripheral circuit which are in contact with at least an underlying silicon oxide film 28 are formed of a W film, the bit lines BL and the interconnect lines 23 to 26 being arranged below the information storing capacitive element C, whereby the adhesion at the interface between the bit lines BL and the interconnect lines 23 to 26 and the silicon oxide film is improved in terms of high-temperature heat treatment to be performed when the capacitive insulating film is being formed.
    Type: Application
    Filed: April 9, 2001
    Publication date: September 20, 2001
    Inventors: Masayoshi Saito, Yoshitaka Nakamura, Hidekazu Goto, Keizo Kawakita, Satoru Yamada, Toshihiro Sekiguchi, Isamu Asano, Yoshitaka Tadaki, Takuya Fukuda, Masayuki Suzuki, Tsuyoshi Tamaru, Naoki Fukuda, Hideo Aoki, Masayoshi Hirasawa
  • Patent number: 6258649
    Abstract: In order to improve connection reliability of a feeding interconnection connected to an electrode of each of the information storage capacitive elements of a DRAM, the formation of a through hole for connecting the information storage capacitive element formed over each memory cell selection MISFET and a feeding interconnection is performed in a process different from that for the formation of a through hole for connecting an interconnection of a second wiring layer in a peripheral circuit, which is formed over the information storage capacitive element and an interconnection corresponding to a first wiring layer.
    Type: Grant
    Filed: September 3, 1999
    Date of Patent: July 10, 2001
    Assignee: Hitachi, LTD
    Inventors: Yoshitaka Nakamura, Masayoshi Hirasawa, Isamu Asano, Tsuyoshi Tamaru, Satoru Yamada, Keizo Kawakita, Toshihiro Sekiguchi, Yoshitaka Tadaki, Takuya Fukuda
  • Patent number: 6215144
    Abstract: In a DRAM having a capacitor-over-bitline structure in which the capacitive insulating film of an information storing capacitive element C is formed of a high dielectric material such as Ta2O5 (tantalum oxide) film 46, the portions of bit lines BL and first-layer interconnect lines 23 to 26 of a peripheral circuit which are in contact with at least an underlying silicon oxide film 28 are formed of a W film, the bit lines BL and the interconnect lines 23 to 26 being arranged below the information storing capacitive element C, whereby the adhesion at the interface between the bit lines BL and the interconnect lines 23 to 26 and the silicon oxide film is improved in terms of high-temperature heat treatment to be performed when the capacitive insulating film is being formed.
    Type: Grant
    Filed: January 25, 1999
    Date of Patent: April 10, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Masayoshi Saito, Yoshitaka Nakamura, Hidekazu Goto, Keizo Kawakita, Satoru Yamada, Toshihiro Sekiguchi, Isamu Asano, Yoshitaka Tadaki, Takuya Fukuda, Masayuki Suzuki, Tsuyoshi Tamaru, Naoki Fukuda, Hideo Aoki, Masayoshi Hirasawa
  • Patent number: 6077735
    Abstract: A method of making semiconductor devices which enables control of the impurity concentration and fine patterning by making removal of residual stress due LOCOS oxidation compatible with the formation of deep wells. A selective oxide layer is formed for separating element regions on a principal plane of a semiconductor substrate, for example, a p.sup.- -type silicon substrate 1. A mask is formed (for example photoresist 47) on the surface including the selective oxide layer and impurities (for example phosphorous) of a conductivity type opposite that of the semiconductor substrate are introduced via an opening in the mask. Then the selective oxide film is annealed by a high-temperature treatment while a deep well (for example n-type deep well 50) is formed by introducing the impurities.
    Type: Grant
    Filed: August 28, 1996
    Date of Patent: June 20, 2000
    Assignee: Texas Instruments Incorporated
    Inventors: Yuji Ezaki, Shinya Nishio, Fumiaki Saitoh, Hideo Nagasawa, Toshiyuki Kaeriyama, Songsu Cho, Hisao Asakura, Jun Murata, Yoshitaka Tadaki, Toshihiro Sekiguchi, Keizo Kawakita
  • Patent number: 6060352
    Abstract: A method for fabricating DRAMs each having a COB structure, and the semiconductor device formed by this method, are provided. In one embodiment, the word line and/or bit line is covered with an insulating film having a comparatively small etching rate. Contact holes are formed while being defined by those insulating films in self-alignment.
    Type: Grant
    Filed: January 28, 1998
    Date of Patent: May 9, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Toshihiro Sekiguchi, Hideo Aoki, Yoshitaka Tadaki, Keizo Kawakita, Jun Murata, Katsuo Yuhara, Michio Nishimura, Kazuhiko Saitoh, Minoru Ohtsuka, Masayuki Yasuda, Toshiyuki Kaeriyama, Songsu Cho
  • Patent number: 6028360
    Abstract: The semiconductor device is formed according to the following steps. A TiN film 71 and a W film 72 are deposited on a silicon oxide film 64 including the inside of a via-hole 66 by the CVD method and thereafter, the W film 72 and TiN film 71 on the silicon oxide film 64 are etched back to leave only the inside of the via-hole 66 and form a plug 73. Then, a TiN film 74, Al-alloy film 75, and Ti film 76 are deposited on the silicon oxide film 64 including the surface of the plug 73 by the sputtering method and thereafter, the Ti film 76, Al-alloy film 75, and TiN film 74 are patterned to form second-layer wirings 77 and 78.
    Type: Grant
    Filed: June 29, 1998
    Date of Patent: February 22, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Yoshitaka Nakamura, Tsuyoshi Tamaru, Naoki Fukuda, Hidekazu Goto, Isamu Asano, Hideo Aoki, Keizo Kawakita, Satoru Yamada, Katsuhiko Tanaka, Hiroshi Sakuma, Masayoshi Hirasawa
  • Patent number: 6023084
    Abstract: A semiconductor memory device has a semiconductor substrate, and memory cells provided at intersections between word line conductors and bit line conductors. Adjacent two memory cells for each bit line conductor form a memory cell pair unit structure, in which first semiconductor regions of the transistors of the adjacent two memory cells are united at their boundary into a single region and are connected to one of the bit line conductors via a bit line connection conductor, the gate electrodes of the transistors of the adjacent two memory cells are connected to word line conductors adjacent to each other, respectively, and the second semiconductor regions of the transistors of the adjacent two memory cells are connected to the respective information storage capacitors.
    Type: Grant
    Filed: October 19, 1998
    Date of Patent: February 8, 2000
    Assignees: Hitachi, Ltd., Texas Instruments Inc.
    Inventors: Yoshitaka Tadaki, Jun Murata, Toshihiro Sekiguchi, Hideo Aoki, Keizo Kawakita, Hiroyuki Uchiyama, Michio Nishimura, Michio Tanaka, Yuji Ezaki, Kazuhiko Saitoh, Katsuo Yuhara, Songsu Cho
  • Patent number: 5937290
    Abstract: In an embodiment of a method of manufacturing semiconductor integrated circuit devices according to the present invention, word lines are provided in a straight form, which serve as gate electrodes of two selecting MOSFETs formed symmetrical about a center portion of an active region surrounded by a LOCOS oxide film on a semiconductor substrate, and bit lines have straight segments and protruding segments. Each protruding segment is formed to protrude from the bit line and is connected through a first contact hole to a first semiconductor region formed at the center portion of the active region. The straight line segments and the protruding segments are formed separately by two separate exposure steps.
    Type: Grant
    Filed: May 27, 1997
    Date of Patent: August 10, 1999
    Assignees: Hitachi, Ltd., Texas Instruments Incorporated
    Inventors: Toshihiro Sekiguchi, Yoshitaka Tadaki, Keizo Kawakita, Katsuo Yuhara, Kazuhiko Saito, Shinya Nishio, Michio Tanaka, Michio Nishimura, Toshiyuki Kaeriyama, Songsu Cho
  • Patent number: 5933726
    Abstract: A semiconductor device, such as a dynamic RAM, and method of making it. A number of stacked cell capacitors are placed at a prescribed spacing in an alignment direction on top of a p.sup.- -type silicon substrate (1). Each capacitor has a nearly perpendicular cylindrical lower electrode (cylindrical polysilicon layer (96)), a dielectric film (silicon nitride film (77)), and upper electrode (plate electrode (78) made of polysilicon). The spacing in the alignment direction is smaller than the inner diameter of the lower electrode.
    Type: Grant
    Filed: August 27, 1996
    Date of Patent: August 3, 1999
    Assignee: Texas Instruments Incorporated
    Inventors: Michio Nishimura, Kazuhiko Saitoh, Masayuki Yasuda, Takashi Hayakawa, Michio Tanaka, Yuji Ezaki, Katsuo Yuhara, Minoru Ohtsuka, Toshikazu Kumai, Songsu Cho, Toshiyuki Kaeriyama, Keizo Kawakita, Toshihiro Sekiguchi, Yoshitaka Tadaki, Jun Murata, Hideo Aoki, Akihiko Konno, Kiyomi Katsuyama, Takafumi Tokunaga, Yoshimi Torii
  • Patent number: 5933724
    Abstract: A phase shifting mask is used for manufacturing a semiconductor integrated circuit device including a conductor pattern in which the line width of patterned conductor strips or the space between patterned conductor strips is not constant. For main transparent areas in the mask corresponding to the conductor pattern, auxiliary pattern segments are provided for compensating changes in the phase distribution of transmitted light caused by changes of the line width or the space. Alternately, the spaces between the conductor strips are adjusted to suppress the changes in the phase distribution of transmitted light. Whether the auxiliary pattern segments should have the phase shifting function is determined depending upon the disposition of the main transparent areas.
    Type: Grant
    Filed: August 26, 1996
    Date of Patent: August 3, 1999
    Assignees: Hitachi, Ltd., Texas Instruments
    Inventors: Toshihiro Sekiguchi, Yoshitaka Tadaki, Keizo Kawakita, Jun Murata, Katsuo Yuhara, Toshikazu Kumai, Michio Tanaka, Michio Nishimura, Kazuhiko Saitoh, Takatoshi Kakizaki, Takeshi Sakai, Toshiyuki Kaeriyama, Songsu Cho