Patents by Inventor Naoki KAWAURA

Naoki KAWAURA 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).

  • Photomask blank, photomask blank making method, and photomask making method
    Patent number: 11073756
    Abstract: A photomask blank is provided comprising a transparent substrate, a first film of chromium-containing material on the substrate, and a second film of silicon/oxygen-containing material disposed contiguous to the first film. The second film includes a first layer contiguous to the first film and a second layer spaced apart from the first layer in film thickness direction. The oxygen content of the first layer is lower than the oxygen content of the second layer. During etching of the first film, this setting prevents an etching rate from ramping up at the interface between the first and second films.
    Type: Grant
    Filed: July 12, 2018
    Date of Patent: July 27, 2021
    Assignee: SHIN-ETSU CHEMICAL CO., LTD.
    Inventors: Takuro Kosaka, Hideo Kaneko, Shigeo Irie, Naoki Kawaura
  • PHOTOMASK BLANK, PHOTOMASK BLANK MAKING METHOD, AND PHOTOMASK MAKING METHOD
    Publication number: 20190033703
    Abstract: A photomask blank is provided comprising a transparent substrate, a first film of chromium-containing material on the substrate, and a second film of silicon/oxygen-containing material disposed contiguous to the first film. The second film includes a first layer contiguous to the first film and a second layer spaced apart from the first layer in film thickness direction. The oxygen content of the first layer is lower than the oxygen content of the second layer. During etching of the first film, this setting prevents an etching rate from ramping up at the interface between the first and second films.
    Type: Application
    Filed: July 12, 2018
    Publication date: January 31, 2019
    Applicant: Shin-Etsu Chemical Co., Ltd.
    Inventors: Takuro KOSAKA, Hideo KANEKO, Shigeo IRIE, Naoki KAWAURA