Patents by Inventor Tsutomu Takaku

Tsutomu Takaku 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: 20020031990
    Abstract: There is disclosed a polishing pad for mirror-polishing a semiconductor wafer, especially in a finish polishing process, by use of a polishing machine which includes a turn table on which a polishing pad is attached, a unit for feeding a polishing agent onto a surface of the polishing pad, and a mechanism for pressing a semiconductor wafer onto the surface of the polishing pad. The polishing pad includes a top layer formed of a porous soft material, a bottom layer formed of a rubber elastomer, and an intermediate layer formed of a hard plastic sheet. The hard plastic sheet is disposed between the top layer and the bottom layer and is bonded to the bottom layer. In the polishing pad, undulation produced in the bottom layer due to a horizontal force generated during polishing is prevented from being transferred to the top layer of the polishing pad, and unevenness in polishing stock removal stemming from warpage or undulation of a wafer itself can be mitigated.
    Type: Application
    Filed: August 23, 2001
    Publication date: March 14, 2002
    Applicant: Shin-Estu Handotai Co., Ltd.
    Inventors: Hisashi Masumura, Makoto Kobayashi, Teruaki Fukami, Tsutomu Takaku, Mamoru Okada
  • Patent number: 6306021
    Abstract: There is disclosed a polishing pad for mirror-polishing a semiconductor wafer, especially in a finish polishing process, by use of a polishing machine which includes a turn table on which a polishing pad is attached, a unit for feeding a polishing agent onto a surface of the polishing pad, and a mechanism for pressing a semiconductor wafer onto the surface of the polishing pad. The polishing pad includes a top layer formed of a porous soft material, a bottom layer formed of a rubber elastomer, and an intermediate layer formed of a hard plastic sheet. The hard plastic sheet is disposed between the top layer and the bottom layer and is bonded to the bottom layer. In the polishing pad, undulation produced in the bottom layer due to a horizontal force generated during polishing is prevented from being transferred to the top layer of the polishing pad, and unevenness in polishing stock removal stemming from warpage or undulation of a wafer itself can be mitigated.
    Type: Grant
    Filed: January 27, 1999
    Date of Patent: October 23, 2001
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Hisashi Masumura, Makoto Kobayashi, Teruaki Fukami, Tsutomu Takaku, Mamoru Okada
  • Patent number: 6190238
    Abstract: A polishing pad for pressing a work to be polished to a surface thereof, includes a structure obtained by being compressed under a temperature which is higher than an operating temperature for polishing the work and/or under a pressure which is equal or higher than an operating pressure for polishing the work. A method for polishing a includes the step of polishing the work by using the polishing pad.
    Type: Grant
    Filed: March 5, 1999
    Date of Patent: February 20, 2001
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Koichi Tanaka, Koji Morita, Tsutomu Takaku
  • Patent number: 6060396
    Abstract: A semiconductor silicon wafer polishing agent and a polishing method using the same are provided for avoiding the need for an increased purity of a polishing agent which may cause a prohibitively high cost, while still preventing semiconductor wafers from being contaminated by metals, particularly by copper and nickel, in a polishing process. The semiconductor silicon wafer polishing agent comprises a silica containing polishing agent as a main component, and Cu and Ni respectively in concentration of 0.01 to 1 ppb with respect to the total amount of the polishing agent.
    Type: Grant
    Filed: December 11, 1998
    Date of Patent: May 9, 2000
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Teruaki Fukami, Tsutomu Takaku
  • Patent number: 5934981
    Abstract: A method and an apparatus, for polishing a thin plate. The method comprises the steps of: rotating a holding plate on one surface of which the thin plate is held to adhere; and bringing the thin plate held on the rotating holding plate into contact with a polishing pad mounted on a surface of a rotating turn table, to polish the thin plate. The step of polishing the one surface of the holding plate is carried out by using the polishing pad for polishing the thin plate before the thin plate is held to adhere on the one surface of the holding plate.
    Type: Grant
    Filed: November 18, 1997
    Date of Patent: August 10, 1999
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Koichi Tanaka, Toshihiro Tsuchiya, Koji Morita, Tsutomu Takaku
  • Patent number: 5797789
    Abstract: A polishing system for polishing a wafer or the like, comprises: a vacuum system comprising a vacuum pump and a vacuum passage connected thereto; a fluid supply system comprising a fluid source and a fluid passage connected thereto; a polishing head comprising a holding member for holding the wafer or the like on the lower surface thereof which has at least one through hole in communication with the vacuum passage and the fluid passage; and a polishing member. Polishing of the wafer or the like is performed by pressing the wafer or the like held on the lower surface of the holding member, against the polishing member while providing relative motion between the holding member and the polishing member and supplying an abrasive slurry to the polishing member. Separation of the wafer or the like from the polishing head is performed by injecting a fluid from the fluid supply system to the object through the through hole of the holding member.
    Type: Grant
    Filed: March 5, 1997
    Date of Patent: August 25, 1998
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Koichi Tanaka, Toshihiro Tsuchiya, Koji Morita, Tsutomu Takaku
  • Patent number: 5733177
    Abstract: The invention concerns a process of polishing wafers, in which a silicon wafer held on a wafer support plate rotatable under a predetermined applied pressure, is polished by mechanochemical polishing in a plurality of polishing steps with an abrasive material interposed between the wafer and a polishing pad cloth applied to a polishing surface plate moved relative to the wafer support plate at a predetermined relative speed. Quality comparable to that of wafers obtainable by a prior art three-step polishing process can be obtained with a two-step wafer polishing step comprising a primary polishing step and a final polishing step. The primary polishing step is performed by setting a high polishing pressure of 300 to 700 g/cm.sup.2 and a reference relative speed of 50 to 150 m/min., and quick increase of the relative speed to 2 to 4 times and quick reduction of the polishing pressure down to 1/2 to 1/10 are caused in a final stage of the primary polishing step.
    Type: Grant
    Filed: July 29, 1996
    Date of Patent: March 31, 1998
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Toshihiro Tsuchiya, Kouichi Tanaka, Kiromasa Hashimoto, Kouji Morita, Tsutomu Takaku