Patents by Inventor Youhei OHKAWA

Youhei OHKAWA 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).

  • Patent number: 9971238
    Abstract: The present invention provides a mask blank including: a transparent substrate, a half-transparent layer for controlling a phase and a transmittance of the exposure light, formed on the transparent substrate, a middle layer formed on the half-transparent layer, and a light-shielding layer formed on the middle layer, wherein the light-shielding layer is constituted with a single metal material not including a transition metal; a film thickness of the light-shielding layer is 40 nm or less; and an optical density of a laminated body, in which three kinds of layers: the half-transparent layer, the middle layer, and the light-shielding layer are laminated, with respect to the exposure light is a value to the extent that the laminated body functions as a light-shielding region or more; the mask blank is used for producing a half tone type phase shift mask, and suitable for a lithography technique on a wafer from 40 nm half pitch and on for its high light-shielding property even thinning the light-shielding pattern
    Type: Grant
    Filed: January 29, 2015
    Date of Patent: May 15, 2018
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventors: Hiroshi Watanabe, Katsuya Hayano, Hideyoshi Takamizawa, Youhei Ohkawa, Takashi Adachi, Ayako Tani, Yoichi Miura
  • Patent number: 9874808
    Abstract: The present invention provides a mask blank used to produce a halftone phase shift mask to which ArF excimer laser exposure light is to be applied. The present invention attains the object by providing the mask blank comprising a transparent substrate, and a light semitransmissive layer formed on the transparent substrate and made only of Si and N or a light semitransmissive layer formed on the transparent substrate and made only of Si, N and O, wherein the light semitransmissive layer has an extinction coefficient of 0.2 to 0.45 at a wavelength of ArF excimer laser exposure light, a refractive index of 2.3 to 2.7 at the wavelength of ArF excimer laser exposure light, and a transmittance of 15 to 38% at the wavelength of ArF excimer laser exposure light, and further has a layer thickness of 57 to 67 nm.
    Type: Grant
    Filed: August 21, 2014
    Date of Patent: January 23, 2018
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventors: Takashi Adachi, Youichi Miura, Hideyoshi Takamizawa, Katsuya Hayano, Youhei Ohkawa, Hiroshi Watanabe, Ayako Tani
  • Publication number: 20170123305
    Abstract: The present invention provides a mask blank including: a transparent substrate, a half-transparent layer for controlling a phase and a transmittance of the exposure light, formed on the transparent substrate, a middle layer formed on the half-transparent layer, and a light-shielding layer formed on the middle layer, wherein the light-shielding layer is constituted with a single metal material not including a transition metal; a film thickness of the light-shielding layer is 40 nm or less; and an optical density of a laminated body, in which three kinds of layers: the half-transparent layer, the middle layer, and the light-shielding layer are laminated, with respect to the exposure light is a value to the extent that the laminated body functions as a light-shielding region or more; the mask blank is used for producing a half tone type phase shift mask, and suitable for a lithography technique on a wafer from 40 nm half pitch and on for its high light-shielding property even thinning the light-shielding pattern
    Type: Application
    Filed: January 29, 2015
    Publication date: May 4, 2017
    Applicant: DAI NIPPON PRINTING CO., LTD.
    Inventors: Hiroshi WATANABE, Katsuya HAYANO, Hideyoshi TAKAMIZAWA, Youhei OHKAWA, Takashi ADACHI, Ayako TANI, Yoichi MIURA
  • Publication number: 20160195803
    Abstract: The present invention provides a mask blank used to produce a halftone phase shift mask to which ArF excimer laser exposure light is to be applied. The present invention attains the object by providing the mask blank comprising a transparent substrate, and a light semitransmissive layer formed on the transparent substrate and made only of Si and N or a light semitransmissive layer formed on the transparent substrate and made only of Si, N and O, wherein the light semitransmissive layer has an extinction coefficient of 0.2 to 0.45 at a wavelength of ArF excimer laser exposure light, a refractive index of 2.3 to 2.7 at the wavelength of ArF excimer laser exposure light, and a transmittance of 15 to 38% at the wavelength of ArF excimer laser exposure light, and further has a layer thickness of 57 to 67 nm.
    Type: Application
    Filed: August 21, 2014
    Publication date: July 7, 2016
    Inventors: Takashi ADACHI, Youichi MIURA, Hideyoshi TAKAMIZAWA, Katsuya HAYANO, Youhei OHKAWA, Hiroshi WATANABE, Ayako TANI