Patents by Inventor Akihiro Kawase

Akihiro Kawase 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: 7481950
    Abstract: A polishing composition of the present invention, which is used in precision polishing the surface of a wafer for semiconductor devices, remarkably reduces haze that occurs on the surface of the wafer. The polishing composition includes silicon dioxide, an alkaline compound, a water-soluble polymer, and water. The silicon dioxide is colloidal silica or fumed silica. The average primary particle diameter DSA of the colloidal silica is from 5 to 30 nm, and the average secondary particle diameter DN4 of the colloidal silica is from 5 to 120 nm. The average primary particle diameter DSA of the fumed silica is from 5 to 30 nm, and the average secondary particle diameter DN4 of the fumed silica is from 5 to 200 nm.
    Type: Grant
    Filed: September 29, 2003
    Date of Patent: January 27, 2009
    Assignee: Fujimi Incorporated
    Inventors: Shuhei Yamada, Akihiro Kawase
  • Patent number: 7481949
    Abstract: A polishing composition and a rinsing composition according to the present invention can effectively suppress wafer contamination caused by metal impurities. The polishing composition includes a chelating agent, an alkali compound, silicon dioxide and water. The rinsing composition includes a chelating agent, an alkali compound and water. The chelating agent contained in the polishing composition and the rinsing composition is an acid represented by the following chemical formula (1) or a salt thereof. In the chemical formula (1), each of Y2 and Y3 represents an alkylene group, n is an integer of 0 to 4, each of 4+n substituents represented by R8 to R12 is an alkyl group. At least four of the alkyl groups have a phosphonic acid group.
    Type: Grant
    Filed: November 7, 2003
    Date of Patent: January 27, 2009
    Assignee: Wako Pure Chemical Industries, Ltd
    Inventors: Akihiro Kawase, Toshihiro Miwa, Kenji Sakamoto, Ichiro Hayashida
  • Publication number: 20060151854
    Abstract: A polishing composition and a rinsing composition according to the present invention can effectively suppress wafer contamination caused by metal impurities. The polishing composition includes a chelating agent, an alkali compound, silicon dioxide and water. The rinsing composition includes a chelating agent, an alkali compound and water. The chelating agent contained in the polishing composition and the rinsing composition is an acid represented by the following chemical formula (1) or a salt thereof. In the chemical formula (1), each of Y2 and Y3 represents an alkylene group, n is an integer of 0 to 4, each of 4+n substituents represented by R8 to R12 is an alkyl group. At least four of the alkyl groups have a phosphonic acid group.
    Type: Application
    Filed: November 7, 2003
    Publication date: July 13, 2006
    Inventors: Akihiro Kawase, Toshihiro Miwa, Kenji Sakamoto, Ichiro Hayashida
  • Patent number: 6852009
    Abstract: A polishing composition which comprises the following components (a) to (d): (a) silicon dioxide, (b) at least one basic substance selected from the group consisting of an inorganic salt of an alkali metal, an ammonium salt, piperazine and ethylenediamine, (c) at least one chelating agent selected from the group consisting of a compound represented by the following general formula [1] and its salt: wherein each of R1 and R2 which are the same or different, is a lower alkylene group, and n is an integer of from 0 to 4, and (d) water.
    Type: Grant
    Filed: February 1, 2002
    Date of Patent: February 8, 2005
    Assignee: Fujimi Incorporated
    Inventors: Akihiro Kawase, Masao Okamura, Yutaka Inoue
  • Publication number: 20040127047
    Abstract: A polishing composition of the present invention, which is used in precision polishing the surface of a wafer for semiconductor devices, remarkably reduces haze that occurs on the surface of the wafer. The polishing composition includes silicon dioxide, an alkaline compound, a water-soluble polymer, and water. The silicon dioxide is colloidal silica or fumed silica. The average primary particle diameter DSA of the colloidal silica is from 5 to 30 nm, and the average secondary particle diameter DN4 of the colloidal silica is from 5 to 120 nm. The average primary particle diameter DSA of the fumed silica is from 5 to 30 nm, and the average secondary particle diameter DN4 of the fumed silica is from 5 to 200 nm.
    Type: Application
    Filed: September 29, 2003
    Publication date: July 1, 2004
    Inventors: Shuhei Yamada, Akihiro Kawase
  • Publication number: 20020151252
    Abstract: A polishing composition which comprises the following components (a) to (d):
    Type: Application
    Filed: February 1, 2002
    Publication date: October 17, 2002
    Applicant: FUJIMI INCORPORATED
    Inventors: Akihiro Kawase, Masao Okamura, Yutaka Inoue
  • Patent number: 6280652
    Abstract: An edge polishing composition for wafers, comprising water and silicon dioxide having an average particle size of from 70 to 2,500 nm.
    Type: Grant
    Filed: June 2, 1999
    Date of Patent: August 28, 2001
    Assignee: Fujimi Incorporated
    Inventors: Yutaka Inoue, Akihiro Kawase