Patents by Inventor Masayuki Nagasawa

Masayuki Nagasawa 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: 20010007795
    Abstract: To solve a problem of non-uniform polishing properties of a circumferential surface area of a substrate, so-called edge sagging phenomenon. When a thin film formed on a top surface of the substrate is polished while holding a back surface of the substrate, local stress at a circumferential end of the substrate is reduced by a guide installed so as to surround the substrate. Also, a deformation of the outer circumferential end portion of the substrate is reduced by a recessed groove provided on the guide. Since a thin film formed on the surface can be polished to be flat throughout the surface of the substrate without an occurrence of non-uniform polishing properties of the outer circumferential surface area of the substrate, so-called edge sagging phenomenon, a high-performance semiconductor device can be manufactured at a high yield and low costs.
    Type: Application
    Filed: January 5, 2001
    Publication date: July 12, 2001
    Inventors: Yoshio Kawamura, Kan Yasui, Masahiko Sato, Souichi Katagiri, Masayuki Nagasawa, Kunio Harada, Satoshi Osabe, Ui Yamaguchi
  • Patent number: 6043155
    Abstract: In order to polish an insulating film, a cerium oxide polishing agent (ceria slurry) is used. The ceria slurry is composed of cerium oxide powder containing Na, Ca, Fe, and Cr concentration of which is less than 10 ppm. Fragile inorganic and organic insulating films formed at relatively low temperatures can be polished without degrading the characteristics of the semiconductor element due to Na diffusion.
    Type: Grant
    Filed: March 3, 1998
    Date of Patent: March 28, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Yoshio Homma, Kikuo Kusukawa, Shigeo Moriyama, Masayuki Nagasawa
  • Patent number: 5772780
    Abstract: An organic insulating film is polished utilizing a polishing agent containing cerium oxide particles (a ceria slurry). The ceria slurry is composed of cerium oxide powder containing a total concentration of Na, Ca, Fe, and Cr of less than 10 ppm. Fragile inorganic and organic insulating films formed at relatively low temperatures can be polished without degrading characteristics of a semiconductor element having such films thereon, due to, e.g., Na diffusion.
    Type: Grant
    Filed: September 21, 1995
    Date of Patent: June 30, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Yoshio Homma, Kikuo Kusukawa, Shigeo Moriyama, Masayuki Nagasawa