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).

  • Patent number: 6969649
    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: Grant
    Filed: March 29, 2004
    Date of Patent: November 29, 2005
    Assignees: Hitachi, Ltd., Texas Instruments Incorporated
    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
  • Publication number: 20050040452
    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: Application
    Filed: October 7, 2004
    Publication date: February 24, 2005
    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: 6853081
    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 4, 2003
    Date of Patent: February 8, 2005
    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: 20040232464
    Abstract: Disclosed are a semiconductor integrated circuit device and a method of manufacturing the same capable of realizing the two-level gate insulator process for the DRAM without increasing the number of manufacturing steps and that of photomasks. After forming a gate electrode of a MISFET which constitutes a memory cell in a memory array region on a semiconductor substrate, the substrate is subjected to thermal treatment (re-oxidation process). At this time, since bird's beak of the thick gate insulating film formed below the sidewall portion of the gate electrode penetrates into the center of the gate electrode, a gate insulating film thicker than the gate insulating film before the re-oxidation process is formed just below the center of the gate electrode.
    Type: Application
    Filed: June 29, 2004
    Publication date: November 25, 2004
    Inventors: Chiemi Hashimoto, Yasuhiko Kawashima, Keizo Kawakita, Masahiro Moniwa, Hiroyasu Ishizuka, Akihiro Shimizu
  • Publication number: 20040209431
    Abstract: An active region 1 has diffusion layers 6a to 8a sandwiched by plural word-lines. The diffusion layer 6a sandwiched by word-lines 2 and 3 locates at a center of the active region 1 and connects to a bit-line through a contact. The diffusion layers 7a and 8a sandwiched by word-lines 2 and 3 and both sides of the active region 1 respectively are connected to capacitor portions. A cell structure is formed of two cell transistors. One cell transistor has the word-line 2 as a gate and the diffusion layers 6a and 7a as source and drain, respectively. The other cell transistor has the word-line 3 as a gate and the diffusion layers 6a and 8a as a source and a drain, respectively. The diffusion layers 7a and 8a placed outside of the active region 1 are n-type and have high carrier concentration of n-type at the region separated from word-lines than to the region close to the word-lines 2 and 3. A p-type substrate exhibits low concentration at the region outside the word-lines.
    Type: Application
    Filed: July 24, 2003
    Publication date: October 21, 2004
    Applicant: Elpida Memory, Inc.
    Inventors: Kiyonori Oyu, Atsushi Ogishima, Hiroyuki Uchiyama, Keizo Kawakita, Masahito Suzuki
  • Publication number: 20040179389
    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: March 29, 2004
    Publication date: September 16, 2004
    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: 6777279
    Abstract: Disclosed are a semiconductor integrated circuit device and a method of manufacturing the same capable of realizing the two-level gate insulator process for the DRAM without increasing the number of manufacturing steps and that of photomasks. After forming a gate electrode of a MISFET which constitutes a memory cell in a memory array region on a semiconductor substrate, the substrate is subjected to thermal treatment (re-oxidation process). At this time, since bird's beak of the thick gate insulating film formed below the sidewall portion of the gate electrode penetrates into the center of the gate electrode, a gate insulating film thicker than the gate insulating film before the re-oxidation process is formed just below the center of the gate electrode.
    Type: Grant
    Filed: April 14, 2003
    Date of Patent: August 17, 2004
    Assignees: Renesas Technology Corp., Hitachi ULSI Systems Co., Ltd., Elpida Memory, Inc.
    Inventors: Chiemi Hashimoto, Yasuhiko Kawashima, Keizo Kawakita, Masahiro Moniwa, Hiroyasu Ishizuka, Akihiro Shimizu
  • Patent number: 6753219
    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: Grant
    Filed: August 23, 2002
    Date of Patent: June 22, 2004
    Assignees: Hitachi, Ltd., Texas Instruments, Inc.
    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
  • Publication number: 20040043546
    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: September 4, 2003
    Publication date: March 4, 2004
    Inventors: Makoto Yoshida, Takahiro Kumauchi, Yoshitaka Tadaki, Isamu Asano, Norio Hasegawa, Keizo Kawakita
  • Patent number: 6649956
    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: August 27, 2002
    Date of Patent: November 18, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Makoto Yoshida, Takahiro Kumauchi, Yoshitaka Tadaki, Isamu Asano, Norio Hasegawa, Keizo Kawakita
  • Publication number: 20030205811
    Abstract: To prevent Al wiring formed on a via-hole in which a CVD-TiN film is embedded from corroding.
    Type: Application
    Filed: June 4, 2003
    Publication date: November 6, 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
  • Patent number: 6638811
    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: May 31, 2002
    Date of Patent: October 28, 2003
    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
  • Publication number: 20030197202
    Abstract: Disclosed are a semiconductor integrated circuit device and a method of manufacturing the same capable of realizing the two-level gate insulator process for the DRAM without increasing the number of manufacturing steps and that of photomasks. After forming a gate electrode of a MISFET which constitutes a memory cell in a memory array region on a semiconductor substrate, the substrate is subjected to thermal treatment (re-oxidation process). At this time, since bird's beak of the thick gate insulating film formed below the sidewall portion of the gate electrode penetrates into the center of the gate electrode, a gate insulating film thicker than the gate insulating film before the re-oxidation process is formed just below the center of the gate electrode.
    Type: Application
    Filed: April 14, 2003
    Publication date: October 23, 2003
    Inventors: Chiemi Hashimoto, Yasuhiko Kawashima, Keizo Kawakita, Masahiro Moniwa, Hiroyasu Ishizuka, Akihiro Shimizu
  • Patent number: 6605530
    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: November 5, 2002
    Date of Patent: August 12, 2003
    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: 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