Patents by Inventor Tomonori Kawasaki

Tomonori Kawasaki 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: 8273260
    Abstract: A method of etching a semiconductor wafer is provided. The method comprises the steps of: jetting a mixed gas including hydrogen fluoride and ozone onto a surface of a semiconductor wafer; monitoring the surface of the semiconductor wafer; analyzing the surface of the semiconductor wafer; and adjusting at least one of the hydrogen fluoride concentration and the ozone concentration in the mixed gas based on a result of the analysis.
    Type: Grant
    Filed: May 13, 2009
    Date of Patent: September 25, 2012
    Assignee: Sumco Techxiv Corporation
    Inventors: Kazuaki Kozasa, Tomonori Kawasaki
  • Publication number: 20120100701
    Abstract: A silicon wafer after being subjected to mirror polishing but before being subjected to form an epitaxial layer thereon is subjected to an ozone gas treatment that oxidizes a surface of the silicon wafer by use of ozone gas, a hydrofluoric acid gas treatment that dissolves and removes the oxidized surface of the silicon wafer by use of hydrofluoric acid gas, and a washing treatment that removes foreign substances remaining on the surface of the silicon wafer, whereby PIDs (Polishing Induced Defects) generated by the mirror polishing are forcedly oxidized, dissolved and removed. By performing epitaxial treatment thereafter, PID-induced convex defects can be prevented from generating on the surface of the epitaxial wafer.
    Type: Application
    Filed: June 24, 2010
    Publication date: April 26, 2012
    Inventor: Tomonori Kawasaki
  • Publication number: 20100093177
    Abstract: A silicon wafer surface other than a defect is oxidized by ozone to form a silicon oxide film. A hydrofluoric acid is sprayed and subsequently a cleaning gas is sprayed onto the surface of the silicon wafer.
    Type: Application
    Filed: September 30, 2009
    Publication date: April 15, 2010
    Applicant: SUMCO TECHXIV CORPORATION
    Inventors: Kazuaki KOZASA, Tomonori KAWASAKI, Takahisa SUGIMAN, Hironori NISHIMURA
  • Patent number: 7666063
    Abstract: A rough-polishing method for conducting a rough polishing before mirror-finish polishing on a semiconductor wafer using a polishing apparatus includes a first polishing step for polishing the semiconductor wafer using slurry containing colloidal silica supplied by a slurry supplying unit and a second polishing step for polishing the semiconductor wafer using alkali solution provided by mixing deionized water supplied from a deionized-water supplying unit and alkali concentrate solution supplied by an alkali-concentrate-solution supplying unit. The pH value of the alkali solution and polishing time in the second polishing step are determined based on the load current value of the polishing table in the first polishing step.
    Type: Grant
    Filed: October 13, 2008
    Date of Patent: February 23, 2010
    Assignee: Sumco Techxiv Corporation
    Inventors: Kazuaki Kozasa, Tomonori Kawasaki, Kosuke Miyoshi
  • Publication number: 20090286333
    Abstract: A method of etching a semiconductor wafer is provided. The method comprises the steps of: jetting a mixed gas including hydrogen fluoride and ozone onto a surface of a semiconductor wafer; monitoring the surface of the semiconductor wafer; analyzing the surface of the semiconductor wafer; and adjusting at least one of the hydrogen fluoride concentration and the ozone concentration in the mixed gas based on a result of the analysis.
    Type: Application
    Filed: May 13, 2009
    Publication date: November 19, 2009
    Inventors: Kazuaki Kozasa, Tomonori Kawasaki
  • Publication number: 20090275213
    Abstract: A processing method of a semiconductor wafer is provided. The method comprising the steps of: removing at least part of oxide film from a surface of the semiconductor wafer; removing liquid from the surface; and providing at least partial oxide film on the surface by applying an oxidizing gas wherein a gas flow of the oxidizing gas and/or an ambient gas involved by the oxidizing gas is characterized by an unsaturated vapor pressure of the liquid such that the liquid on the surface vaporizes. The above-described steps are conducted in this order.
    Type: Application
    Filed: May 1, 2009
    Publication date: November 5, 2009
    Inventors: Isamu Gotou, Tomonori Kawasaki
  • Patent number: 7540800
    Abstract: A rough-polishing method for conducting a rough polishing before mirror-finish polishing on a semiconductor wafer (W) using a polishing apparatus (1) includes a first polishing step for polishing the semiconductor wafer using slurry containing colloidal silica supplied by a slurry supplying unit (4) and a second polishing step for polishing the semiconductor wafer using alkali solution provided by mixing deionized water supplied from a deionized-water supplying unit (5) and alkali concentrate solution supplied by an alkali-concentrate-solution supplying unit (6). The pH value of the alkali solution and polishing time in the second polishing step are determined based on the load current value of the polishing table (2) in the first polishing step.
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: June 2, 2009
    Assignee: Sumco Techxiv Corporation
    Inventors: Kazuaki Kozasa, Tomonori Kawasaki, Kosuke Miyoshi
  • Publication number: 20090042482
    Abstract: A rough-polishing method for conducting a rough polishing before mirror-finish polishing on a semiconductor wafer using a polishing apparatus includes a first polishing step for polishing the semiconductor wafer using slurry containing colloidal silica supplied by a slurry supplying unit and a second polishing step for polishing the semiconductor wafer using alkali solution provided by mixing deionized water supplied from a deionized-water supplying unit and alkali concentrate solution supplied by an alkali-concentrate-solution supplying unit. The pH value of the alkali solution and polishing time in the second polishing step are determined based on the load current value of the polishing table in the first polishing step.
    Type: Application
    Filed: October 13, 2008
    Publication date: February 12, 2009
    Applicant: SUMCO TECHXIV CORPORATION
    Inventors: Kazuaki KOZASA, Tomonori KAWASAKI, Kosuke MIYOSHI
  • Publication number: 20080081541
    Abstract: A rough-polishing method for conducting a rough polishing before mirror-finish polishing on a semiconductor wafer (W) using a polishing apparatus (1) includes a first polishing step for polishing the semiconductor wafer using slurry containing colloidal silica supplied by a slurry supplying unit (4) and a second polishing step for polishing the semiconductor wafer using alkali solution provided by mixing deionized water supplied from a deionized-water supplying unit (5) and alkali concentrate solution supplied by an alkali-concentrate-solution supplying unit (6). The pH value of the alkali solution and polishing time in the second polishing step are determined based on the load current value of the polishing table (2) in the first polishing step.
    Type: Application
    Filed: September 28, 2007
    Publication date: April 3, 2008
    Applicant: SUMCO TECHXIV CORPORATION
    Inventors: Kazuaki Kozasa, Tomonori Kawasaki, Kosuke Miyoshi
  • Patent number: 4106087
    Abstract: A power-supply device for a working machine such as a spark-erosion machine, arc welding machine or the like substantially eliminates the break-down or misoperation of thyristers used in the device and wherein the device includes a circuit which comprises a power transformer, a thyrister rectifying circuit, a diode rectifying circuit, and a trigger circuit for triggering the thyrister of the thyrister rectifying circuit.
    Type: Grant
    Filed: November 3, 1976
    Date of Patent: August 8, 1978
    Inventor: Tomonori Kawasaki