Patents by Inventor Yoko Tomofuji

Yoko Tomofuji 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).

  • Reticle
    Patent number: 5837405
    Abstract: In a reticle, a semi-transparent film pattern in place of a light blocking film pattern is used as a mask pattern having a size within a certain range, whereby an exposure system can be improved in resolution limit and faithful pattern transfer can be realized with a constant light quantity. A reticle may be of a stacked layer structure which comprises a shift film for providing a different optical path to exposure light, a mask substrate formed on the top or bottom of the shift film, and a transmissivity ratio adjustment layer having a predetermined transmissivity ratio to the exposure light. The material of a phase shifter may be adjusted in amplitude transmissivity ratio so that a shifter width for effectively improving a contrast can be made large and an accuracy necessary for a shifter width can be loosened.
    Type: Grant
    Filed: October 27, 1997
    Date of Patent: November 17, 1998
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoko Tomofuji, Makoto Nakase, Takashi Sato, Hiroaki Hazama, Haruki Komano, Shinichi Ito
  • Reticle and method of fabricating reticle
    Patent number: 5660956
    Abstract: In a reticle, a semi-transparent film pattern in place of a light blocking film pattern is used as a mask pattern having a size within a certain range, whereby an exposure system can be improved in resolution limit and faithful pattern transfer can be realized with a constant light quantity. A reticle may be of a stacked layer structure which comprises a shift film for providing a different optical path to exposure light, a mask substrate formed on the top or bottom of the shift film, and a transmissivity ratio adjustment layer having a predetermined transmissivity ratio to the exposure light. The material of a phase shifter may be adjusted in amplitude transmissivity ratio so that a shifter width for effectively improving a contrast can be made large and an accuracy necessary for a shifter width can be loosened.
    Type: Grant
    Filed: February 29, 1996
    Date of Patent: August 26, 1997
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoko Tomofuji, Makoto Nakase, Takashi Sato, Hiroaki Hazama, Haruki Komano, Shinichi Ito
  • Method of exposing light in a method of fabricating a reticle
    Patent number: 5595844
    Abstract: In a reticle, a semi-transparent film pattern in place of a light blocking film pattern is used as a mask pattern having a size within a certain range, whereby an exposure system can be improved in resolution limit and faithful pattern transfer can be realized with a constant light quantity. A reticle may be of a stacked layer structure which comprises a shift film for providing a different optical path to exposure light, a mask substrate formed on the top or bottom of the shift film, and a transmissivity ratio adjustment layer having a predetermined transmissivity ratio to the exposure light. The material of a phase shifter may be adjusted in amplitude transmissivity ratio so that a shifter width for effectively improving a contrast can be made large and an accuracy necessary for a shifter width can be loosened.
    Type: Grant
    Filed: May 30, 1995
    Date of Patent: January 21, 1997
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoko Tomofuji, Makoto Nakase, Takashi Sato, Hiroaki Hazama, Haruki Komano, Shinichi Ito
  • Method of fabricating a reticle
    Patent number: 5589305
    Abstract: In a reticle, a semi-transparent film pattern in place of a light blocking film pattern is used as a mask pattern having a size within a certain range, whereby an exposure system can be improved in resolution limit and faithful pattern transfer can be realized with a constant light quantity. A reticle may be of a stacked layer structure which comprises a shift film for providing a different optical path to exposure light, a mask substrate formed on the top or bottom of the shift film, and a transmissivity ratio adjustment layer having a predetermined transmissivity ratio to the exposure light. The material of a phase shifter may be adjusted in amplitude transmissivity ratio so that a shifter width for effectively improving a contrast can be made large and an accuracy necessary for a shifter width can be loosened.
    Type: Grant
    Filed: May 30, 1995
    Date of Patent: December 31, 1996
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoko Tomofuji, Makoto Nakase, Takashi Sato, Hiroaki Hazama, Haruki Komano, Shinichi Ito