Patents by Inventor Doris Kwok

Doris Kwok 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).

  • Polishing slurry
    Patent number: 6491837
    Abstract: The polishing slurry includes polishing particles having a mean particle diameter of less than about 5 &mgr;m. The slurry contains at least about 0.5 total weight percent oxidizer selected from at least one of the group consisting of HNO3, Ni(NO3)2, Al(NO3)3, Mg(NO3)2, Zn(NO3)2 and NH4NO3. A small but effective amount of a co-oxidizer selected from the group consisting of perbromates, perchlorates, periodates, persulfates, permanganates, ferric nitrate, cerium-containing salts, perbenzoic acids, nitrite compounds, perborate compounds, hypochlorite compounds, chlorite compounds and chloride compounds accelerates removal of substrates; and water forms the balance of the aqueous slurry.
    Type: Grant
    Filed: December 21, 2000
    Date of Patent: December 10, 2002
    Assignee: Praxair S.T. Technology, Inc.
    Inventors: Lei Liu, Doris Kwok
  • Polishing slurry
    Patent number: 6299795
    Abstract: The polishing slurry includes polishing particles having a mean particle diameter of less than about 5 &mgr;m. The slurry contains at least about 0.5 weight percent oxidizer selected from at least one of the group consisting of HNO3, Ni(NO3)2, Al(NO3)3, Mg(NO3)2, Zn(NO3)2 and NH4NO3. A small but effective amount of a co-oxidizer selected from the group consisting of perbromates, perchlorates, periodates, persulfates, permanganates and ferric nitrate accelerates removal of substrates; and water forms the balance of the aqueous slurry.
    Type: Grant
    Filed: January 18, 2000
    Date of Patent: October 9, 2001
    Assignee: Praxair S.T. Technology, Inc.
    Inventors: Lei Liu, Doris Kwok
  • Hybrid polishing slurry
    Patent number: 6261476
    Abstract: A hybrid slurry mixture that polishes substrates' surfaces. The hybrid slurry includes, by weight percent, 1 to 30 primary polishing particles, 1 to 50 dispersed colloidal particles, 1 to 40 oxidizer and balance water. The primary polishing particles are metal compounds selected from the group consisting of oxides, nitrides, carbides and borides. The primary polishing particles have a particle size from about 0.1 to 2 &mgr;m mean diameter. The dispersed colloidal particles are at least one oxide selected from the group consisting of alumina and silica. The dispersed colloidal particles have a particle size from about 2 to 500 nm mean diameter.
    Type: Grant
    Filed: March 21, 2000
    Date of Patent: July 17, 2001
    Assignee: Praxair S. T. Technology, Inc.
    Inventors: Doris Kwok, James Kent Knapp
  • Polishing slurry
    Patent number: 6162268
    Abstract: The invention provides a mixture for polishing surfaces. The mixture includes polishing particles having an average size of less than 10 .mu.m and water. It also includes an accelerator for chemically attacking a surface and a starch for reducing vibration of polishing machines.
    Type: Grant
    Filed: May 3, 1999
    Date of Patent: December 19, 2000
    Assignee: Praxair S. T. Technology, Inc.
    Inventors: James Kent Knapp, Doris Kwok