Patents by Inventor Kazunobu Shigehara

Kazunobu Shigehara 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).

  • Semiconductor device and method for manufacturing the same
    Patent number: 6593233
    Abstract: In a semiconductor device having a metal wiring conductor connected to a contact hole formed through an interlayer insulator layer formed on a lower level circuit, a lower level tungsten film is deposited under a condition giving an excellent step coverage so as to fill the contact hole, and an upper level tungsten film is further deposited under a condition of forming a film having a stress smaller than that of the lower level tungsten film. The metal wiring conductor is formed of a double layer which is composed of the lower level tungsten film and the upper level tungsten film, and therefore, has a reduced stress in the whole of the film. Thus, there is obtained the tungsten film wiring conductor which fills the inside of the contact hole with no void and therefore has a high reliability, and which has a low film stress. In addition, the number of steps in the manufacturing process can be reduced.
    Type: Grant
    Filed: June 9, 1998
    Date of Patent: July 15, 2003
    Assignee: NEC Electronics Corporation
    Inventors: Kazuki Miyazaki, Kazunobu Shigehara, Masanobu Zenke
  • Semiconductor device having a wiring layer and method for manufacturing same
    Patent number: 5843840
    Abstract: In a semiconductor device having a metal wiring conductor connected to a contact hole formed through an interlayer insulator layer formed on a lower level circuit, a lower level tungsten film is deposited under a condition giving an excellent step coverage so as to fill the contact hole, and an upper level tungsten film is further deposited under a condition of forming a film having a stress smaller than that of the lower level tungsten film. The metal wiring conductor is formed of a double layer which is composed of the lower level tungsten film and the upper level tungsten film, and therefore, has a reduced stress in the whole of the film. Thus, there is obtained the tungsten film wiring conductor which fills the inside of the contact hole with no void and therefore has a high reliability, and which has a low film stress. In addition, the number of steps in the manufacturing process can be reduced.
    Type: Grant
    Filed: March 4, 1996
    Date of Patent: December 1, 1998
    Assignee: NEC Corporation
    Inventors: Kazuki Miyazaki, Kazunobu Shigehara, Masanobu Zenke
  • Semiconductor device having multilayered wiring structure
    Patent number: 5798569
    Abstract: In a semiconductor device having a metal wiring conductor connected to a contact hole formed through an interlayer insulator layer formed on a lower level circuit, a lower level tungsten film is deposited under a condition giving an excellent step coverage so as to fill the contact hole, and an upper level tungsten film is further deposited under a condition of forming a film having a stress smaller than that of the lower level tungsten film. The metal wiring conductor is formed of a double layer which is composed of the lower level tungsten film and the upper level tungsten film, and therefore, has a reduced stress in the whole of the film. Thus, there is obtained the tungsten film wiring conductor which fills the inside of the contact hole with no void and therefore has a high reliability, and which has a low film stress. In addition, the number of steps in the manufacturing process can be reduced.
    Type: Grant
    Filed: July 17, 1997
    Date of Patent: August 25, 1998
    Assignee: NEC Corporation
    Inventors: Kazuki Miyazaki, Kazunobu Shigehara, Masanobu Zenke