Patents by Inventor Tomomi Kurokawa

Tomomi Kurokawa 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).

  • Method for forming a capacitor in a memory cell in a dynamic random access memory device
    Patent number: 5897983
    Abstract: In a method for forming an annular-shaped and vertically extending bottom electrode of a memory cell capacitor, a conductive film is formed on an inter-layer insulator. A photo-resist material is applied on the conductive film to form a photo-resist film thereon. The photo-resist film is patterned by a photo-lithography using a mask which includes a transparent plate-like body and a phase shifting film selectively provided on a predetermined region of the transparent plate-like body to form an annular-shaped and vertically extending photo-resist pattern over the conductive film. The conductive film is subjected to an anisotropic etching, in which the annular-shaped and vertically extending photo-resist pattern is used as a mask, to form an annular-shaped and vertically extending bottom electrode under the annular-shaped and vertically extending photo-resist pattern. The annular-shaped and vertically extending photo-resist pattern is removed.
    Type: Grant
    Filed: May 30, 1996
    Date of Patent: April 27, 1999
    Assignee: NEC Corporation
    Inventors: Toshiyuki Hirota, Tomomi Kurokawa, Masanobu Zenke, Kazuki Yokota