Patents by Inventor Takafumi Sakurada

Takafumi Sakurada 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: 20090165396
    Abstract: The present invention provides a method of producing oxide particles, comprising a step of mixing a metal carbonate with an acid to give a mixture, a step of heating the mixture to give a metal oxide and a step of pulverizing the metal oxide, and slurry wherein metal oxide particles obtained by the above method of producing are dispersed in an aqueous medium, a polishing slurry, and a method of polishing a substrate. Particularly, the present invention provides a polishing slurry containing cerium oxide particles obtained by using cerium carbonate as the metal carbonate material and oxalic acid as the acid. The present invention provides a method of producing oxide particles, wherein coarse particle- and abrasion powder-free fine particles can be rapidly obtained. The present invention also provides a polishing slurry using the oxide particles, which can maintain a suitable polishing rate, can reduce generation of scratches, and can accurately polish the surface of a semiconductor.
    Type: Application
    Filed: April 20, 2007
    Publication date: July 2, 2009
    Applicant: HITACHI CHEMICAL CO., LTD.
    Inventors: Takafumi Sakurada, Daisuke Hosaka, Kanshi Chinone
  • Publication number: 20090156007
    Abstract: The present invention relates to polishing slurry and polishing method used for polishing in a process for forming wirings of a semiconductor device, and the like. There are provided polishing slurry giving a polished surface having high flatness even if the polished surface is made of two or more substances, and further, capable of suppressing metal residue and scratches after polishing, and a method of chemical mechanical polishing using this. The polishing slurry of the present invention is polishing slurry containing at least one of a surfactant and an organic solvent, and a metal oxide dissolving agent and water, or polishing slurry containing water and abrasive of which surface has been modified with an alkyl group, and preferably, it further contains a metal oxidizer, water-soluble polymer, and metal inhibitor.
    Type: Application
    Filed: February 4, 2009
    Publication date: June 18, 2009
    Applicant: HITACHI CHEMICAL CO., LTD.
    Inventors: Jin Amanokura, Takafumi Sakurada, Sou Anzai, Masato Fukasawa, Shouichi Sasaki
  • Publication number: 20070232197
    Abstract: The present invention relates to polishing slurry and polishing method used for polishing in a process for forming wirings of a semiconductor device, and the like. There are provided polishing slurry giving a polished surface having high flatness even if the polished surface is made of two or more substances, and further, capable of suppressing metal residue and scratches after polishing, and a method of chemical mechanical polishing using this. The polishing slurry of the present invention is polishing slurry containing at least one of a surfactant and an organic solvent, and a metal oxide dissolving agent and water, or polishing slurry containing water and abrasive, wherein the surface of the abrasive is modified with an alkyl group, and preferably, it further contains a metal oxidizer, water-soluble polymer, and metal inhibitor.
    Type: Application
    Filed: May 25, 2007
    Publication date: October 4, 2007
    Applicant: HITACHI CHEMICAL CO., LTD.
    Inventors: Jin Amanokura, Takafumi Sakurada, Sou Anzai, Masato Fukasawa, Shouichi Sasaki
  • Publication number: 20070147551
    Abstract: A CMP slurry is mixed with an oxidant in polishing and contains a copper rust inhibitor, a water-soluble polymer, a pH controller capable of forming a complex with copper, and water, and is substantially free from abrasive. The CMP slurry effectively reduces dishing in chemical polishing of copper and forms reliable wiring. Preferably, the contents of the rust inhibitor, the water-soluble polymer, and the oxidant are 0.1 to 5 wt %, 0.05 to 5 wt %, and 0.01 to 5M relative to 1 liter of the CMP slurry, respectively, and the amount of the pH controller is a necessary amount for adjusting pH of the CMP slurry to 1.5 to 2.5.
    Type: Application
    Filed: December 22, 2006
    Publication date: June 28, 2007
    Inventors: Katsumi Mabuchi, Haruo Akahoshi, Masanobu Habiro, Takafumi Sakurada, Yutaka Nomura
  • Publication number: 20070117394
    Abstract: The invention provides polishing slurry for CMP for suppressing corrosion of wiring lines of a conductive substance, or for suppressing bimetallic corrosion of a barrier conductor and conductive substance, by suppressing electrons from being transferred at near the boundaries between a barrier conductor and a conductive substance such as copper. The invention provides polishing slurry for CMP for polishing at least a conductor layer and a conductive substance layer in contact with the conductor layer, wherein the absolute value of the potential difference between the conductive substance and the conductor at 50±5° C. is 0.25 V or less in the polishing slurry when a positive electrode and a negative electrode of a potentiometer are connected to the conductive substance and the conductor, respectively.
    Type: Application
    Filed: October 11, 2006
    Publication date: May 24, 2007
    Applicant: HITACHI CHEMICAL CO., LTD.
    Inventors: Takashi Shinoda, Shigeru Nobe, Takafumi Sakurada, Yoshikazu Oomori, Tadahiro Kimura
  • Publication number: 20050050803
    Abstract: The present invention relates to polishing slurry and polishing method used for polishing in a process for forming wirings of a semiconductor device, and the like. There are provided polishing slurry giving a polished surface having high flatness even if the polished surface is made of two or more substances, and further, capable of suppressing metal residue and scratches after polishing, and a method of chemical mechanical polishing using this. The polishing slurry of the present invention is polishing slurry containing at least one of a surfactant and an organic solvent, and a metal oxide dissolving agent and water, or polishing slurry containing water and abrasive of which surface has been modified with an alkyl group, and preferably, it further contains a metal oxidizer, water-soluble polymer, and metal inhibitor.
    Type: Application
    Filed: October 31, 2002
    Publication date: March 10, 2005
    Inventors: Jin Amanokura, Takafumi Sakurada, Sou Anzai, Masato Fukasawa, Shouichi Sasaki