Patents by Inventor Ryo Ohkubo

Ryo Ohkubo 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).

  • Publication number: 20160202603
    Abstract: A mask blank wherein damage to a light semitransmissive film due to dry etching for removing a light shielding film is inhibited. Mask blank 100 has a light semitransmissive film 2 and light shielding film 4 laminated on a main surface of a transparent substrate 1. Film 2 can be dry etched with a fluorine-based gas. Film 4 has laminated lower layer 41 and upper layer 42. Lower layer 41 contained tantalum and id substantially free from hafnium, zirconium, and oxygen. Upper layer 42 contains tantalum and one or more of hafnium and zirconium and is substantially free from oxygen excluding the surface layer of the upper layer 42. Between the light semitransmissive film 2 and lower layer 41 is an etching stopper film 3 having etch selectivity with respect to the lower layer 41 in dry etching with an etching gas containing the chlorine-based gas and no oxygen gas.
    Type: Application
    Filed: August 15, 2014
    Publication date: July 14, 2016
    Applicant: HOYA CORPORATION
    Inventors: Hiroaki SHISHIDO, Ryo OHKUBO, Osamu NOZAWA
  • Publication number: 20160202602
    Abstract: In a mask blank having a structure in which a light-semitransmissive film and a light-shielding film are laminated on a main surface of a transparent substrate, the light-semitransmissive film is made of a material that can be dry-etched with an etching gas containing a fluorine-based gas, the light-shielding film is made of a material that contains tantalum and one or more elements selected from hafnium and zirconium and contains no oxygen except in a surface layer thereof, an etching stopper film is provided between the light-semitransmissive film and the light-shielding film, and the etching stopper film is made of a material that contains chromium with an oxygen content of 20 at % or less.
    Type: Application
    Filed: May 19, 2014
    Publication date: July 14, 2016
    Applicant: HOYA CORPORATION
    Inventors: Hiroaki SHISHIDO, Osamu NOZAWA, Ryo OHKUBO
  • Publication number: 20160187769
    Abstract: A mask blank is provided, by which an alignment mark can be formed between a transparent substrate and a laminated structure of a light semitransmissive film, etching stopper film, and light shielding film during manufacture of a transfer mask.
    Type: Application
    Filed: September 5, 2014
    Publication date: June 30, 2016
    Applicant: HOYA CORPORATION
    Inventors: Osamu NOZAWA, Ryo OHKUBO, Hiroaki SHISHIDO, Yasushi OKUBO
  • Publication number: 20150261083
    Abstract: The present invention is a reflective mask blank used to fabricate a reflective mask, which has a laminated structure of a multilayer reflective film, an absorber film and an etching mask film in this order on a substrate, wherein the etching mask film comprises a material containing chromium, the absorber film comprises a material containing tantalum, a highly oxidized layer is formed on the surface layer of the absorber film on the opposite side from the substrate, and a Ta 4f narrow spectrum of the highly oxidized layer when analyzed by X-ray photoelectron spectroscopy has a maximum peak at a binding energy of more than 23 eV.
    Type: Application
    Filed: June 3, 2015
    Publication date: September 17, 2015
    Applicant: HOYA CORPORATION
    Inventors: Kazuya SAKAI, Ryo OHKUBO, Osamu NOZAWA, Toshiyuki SUZUKI
  • Publication number: 20150198873
    Abstract: A mask blank suitable for fabricating a phase shift mask having a thin film pattern composed of a material enabling dry etching with a fluorine-based gas and a substrate-engraved pattern. The mask blank 100 is used to fabricate a phase shift mask having a thin film pattern and a substrate-engraved pattern. The mask blank 100 has a structure in which an etching stopper film 2, a thin film for pattern formation 3 and an etching mask film 4 are laminated in this order on a transparent substrate 1. The etching stopper film 2 is made of a material that contains chromium and oxygen and the oxygen content thereof is more than 50 at %. The thin film 3 is made of a material that can be dry-etched by a fluorine-based gas. The etching mask film 4 is made of a material that contains chromium, the chromium content thereof is not less than 45 at %, and the oxygen content thereof is not more than 30 at %.
    Type: Application
    Filed: June 25, 2013
    Publication date: July 16, 2015
    Applicant: HOYA CORPORATION
    Inventors: Yasushi Okubo, Ryo Ohkubo
  • Patent number: 9075315
    Abstract: The present invention is a reflective mask blank used to fabricate a reflective mask, which has a laminated structure of a multilayer reflective film, an absorber film and an etching mask film in this order on a substrate, wherein the etching mask film comprises a material containing chromium, the absorber film comprises a material containing tantalum, a highly oxidized layer is formed on the surface layer of the absorber film on the opposite side from the substrate, and a Ta 4f narrow spectrum of the highly oxidized layer when analyzed by X-ray photoelectron spectroscopy has a maximum peak at a binding energy of more than 23 eV.
    Type: Grant
    Filed: September 27, 2012
    Date of Patent: July 7, 2015
    Assignee: HOYA CORPORATION
    Inventors: Kazuya Sakai, Ryo Ohkubo, Osamu Nozawa, Toshiyuki Suzuki
  • Patent number: 9029048
    Abstract: The present invention is a mask blank used to fabricate a transfer mask, which has a laminated structure of a light shielding film and an etching mask film in this order on a transparent substrate, wherein the etching mask film comprises a material containing chromium, the light shielding film comprises a material containing tantalum, a highly oxidized layer is formed on the surface layer of the light shielding film on the opposite side from the transparent substrate, and a Ta 4 f narrow spectrum of the highly oxidized layer analyzed by X-ray photoelectron spectroscopy has a maximum peak at a binding energy of more than 23 eV.
    Type: Grant
    Filed: September 27, 2012
    Date of Patent: May 12, 2015
    Assignee: Hoya Corporation
    Inventors: Kazuya Sakai, Ryo Ohkubo, Osamu Nozawa, Toshiyuki Suzuki
  • Patent number: 8221941
    Abstract: A thin film made of a material containing a metal and silicon is formed on a light-transmissive substrate. Then, a treatment is performed to modify a main surface of the thin film in advance so that when exposure light having a wavelength of 200 nm or less is accumulatively irradiated on a thin film pattern of a photomask to be produced by patterning the thin film, the transfer characteristic of the thin film pattern does not change more than a predetermined degree. This treatment is performed by carrying out, for example, a heat treatment in an atmosphere containing oxygen at 450° C. to 900° C.
    Type: Grant
    Filed: December 28, 2009
    Date of Patent: July 17, 2012
    Assignee: Hoya Corporation
    Inventors: Toshiyuki Suzuki, Masahiro Hashimoto, Kazunori Ono, Ryo Ohkubo, Kazuya Sakai
  • Publication number: 20100167185
    Abstract: A thin film made of a material containing a metal and silicon is formed on a light-transmissive substrate. Then, a treatment is performed to modify a main surface of the thin film in advance so that when exposure light having a wavelength of 200 nm or less is accumulatively irradiated on a thin film pattern of a photomask to be produced by patterning the thin film, the transfer characteristic of the thin film pattern does not change more than a predetermined degree. This treatment is performed by carrying out, for example, a heat treatment in an atmosphere containing oxygen at 450° C. to 900° C.
    Type: Application
    Filed: December 28, 2009
    Publication date: July 1, 2010
    Applicant: HOYA CORPORATION
    Inventors: Toshiyuki SUZUKI, Masahiro HASHIMOTO, Kazunori ONO, Ryo OHKUBO, Kazuya SAKAI
  • Patent number: 7632612
    Abstract: A halftone phase shift mask blank for use in manufacturing a halftone phase shift mask comprises a transparent substrate, a light transmitting portion formed on the substrate for transmitting an exposure light beam, a phase shifter portion formed on the substrate for transmitting a part of the exposure light beam as a transmitted light beam and for shifting a phase of the transmitted light beam by a predetermined amount, and a phase shifter film for forming the phase shifter portion. The halftone phase shift mask has an optical characteristic such that light beams passing through the light transmitting portion and through the phase shifter portion cancel each other in the vicinity of a boundary portion therebetween, thereby maintaining and improving an excellent contrast at a boundary portion of an exposure pattern to be transferred onto the surface of an object to be exposed.
    Type: Grant
    Filed: July 3, 2006
    Date of Patent: December 15, 2009
    Assignee: Hoya Corporation
    Inventors: Yuuki Shiota, Osamu Nozawa, Ryo Ohkubo, Hideaki Mitsui
  • Patent number: 7282305
    Abstract: A reflective mask blank has a substrate (1) and a reflective multilayer film (3) formed on the substrate to reflect exposure light. The substrate has a base pattern (2) formed by a predetermined irregularity. On a surface of the reflective multilayer film formed on the base pattern, a step portion corresponding to the base pattern is formed as a programmed defect.
    Type: Grant
    Filed: March 2, 2004
    Date of Patent: October 16, 2007
    Assignee: Hoya Corporation
    Inventors: Tsutomo Shoki, Ryo Ohkubo, Takeru Kinoshita
  • Publication number: 20070082278
    Abstract: A halftone phase shift mask blank for use in manufacturing a halftone phase shift mask comprises a transparent substrate, a light transmitting portion formed on the substrate for transmitting an exposure light beam, a phase shifter portion formed on the substrate for transmitting a part of the exposure light beam as a transmitted light beam and for shifting a phase of the transmitted light beam by a predetermined amount, and a phase shifter film for forming the phase shifter portion. The halftone phase shift mask has an optical characteristic such that light beams passing through the light transmitting portion and through the phase shifter portion cancel each other in the vicinity of a boundary portion therebetween, thereby maintaining and improving an excellent contrast at a boundary portion of an exposure pattern to be transferred onto the surface of an object to be exposed.
    Type: Application
    Filed: July 3, 2006
    Publication date: April 12, 2007
    Inventors: Yuuki Shiota, Osamu Nozawa, Ryo Ohkubo, Hideaki Mitsui
  • Patent number: 7115341
    Abstract: A halftone phase shift mask blank for use in manufacturing a halftone phase shift mask comprises a transparent substrate, a light transmitting portion formed on the substrate for transmitting an exposure light beam, a phase shifter portion formed on the substrate for transmitting a part of the exposure light beam as a transmitted light beam and for shifting a phase of the transmitted light beam by a predetermined amount, and a phase shifter film for forming the phase shifter portion. The halftone phase shift mask has an optical characteristic such that light beams passing through the light transmitting portion and through the phase shifter portion cancel each other in the vicinity of a boundary portion therebetween, thereby maintaining and improving an excellent contrast at a boundary portion of an exposure pattern to be transferred onto the surface of an object to be exposed.
    Type: Grant
    Filed: February 24, 2003
    Date of Patent: October 3, 2006
    Assignee: Hoya Corporation
    Inventors: Yuuki Shiota, Osamu Nozawa, Ryo Ohkubo, Hideaki Mitsui
  • Patent number: 7011910
    Abstract: In a halftone-type phase-shift mask blank having a phase shifter film 5, the phase shifter film 5 has a phase adjustment layer 4 for primarily controlling the phase of exposure light, and a transmissivity adjustment layer 3 which is formed between a transparent substrate 2 and the phase adjustment layer 4 and primarily controls the transmissivity of exposure light. The transmissivity adjustment layer 3 has a thickness of 90 angstroms or less.
    Type: Grant
    Filed: April 24, 2003
    Date of Patent: March 14, 2006
    Assignee: Hoya Corporation
    Inventors: Yuki Shiota, Osamu Nozawa, Hideaki Mitsui, Ryo Ohkubo
  • Publication number: 20040175633
    Abstract: A reflective mask blank has a substrate (1) and a reflective multilayer film (3) formed on the substrate to reflect exposure light. The substrate has a base pattern (2) formed by a predetermined irregularity. On a surface of the reflective multilayer film formed on the base pattern, a step portion corresponding to the base pattern is formed as a programmed defect.
    Type: Application
    Filed: March 2, 2004
    Publication date: September 9, 2004
    Applicant: HOYA CORPORATION
    Inventors: Tsutomo Shoki, Ryo Ohkubo, Takeru Kinoshita
  • Publication number: 20040086788
    Abstract: In a halftone-type phase-shift mask blank having a phase shifter film 5, the phase shifter film 5 has a phase adjustment layer 4 for primarily controlling the phase of exposure light, and a transmissivity adjustment layer 3 which is formed between a transparent substrate 2 and the phase adjustment layer 4 and primarily controls the transmissivity of exposure light. The transmissivity adjustment layer 3 has a thickness of 90 angstroms or less.
    Type: Application
    Filed: April 24, 2003
    Publication date: May 6, 2004
    Applicant: HOYA CORPORATION
    Inventors: Yuki Shiota, Osamu Nozawa, Hideaki Mitsui, Ryo Ohkubo
  • Publication number: 20030180631
    Abstract: A halftone phase shift mask blank for use in manufacturing a halftone phase shift mask comprises a transparent substrate, a light transmitting portion formed on the substrate for transmitting an exposure light beam, a phase shifter portion formed on the substrate for transmitting a part of the exposure light beam as a transmitted light beam and for shifting a phase of the transmitted light beam by a predetermined amount, and a phase shifter film for forming the phase shifter portion. The halftone phase shift mask has an optical characteristic such that light beams passing through the light transmitting portion and through the phase shifter portion cancel each other in the vicinity of a boundary portion therebetween, thereby maintaining and improving an excellent contrast at a boundary portion of an exposure pattern to be transferred onto the surface of an object to be exposed.
    Type: Application
    Filed: February 24, 2003
    Publication date: September 25, 2003
    Applicant: HOYA CORPORATION
    Inventors: Yuuki Shiota, Osamu Nozawa, Ryo Ohkubo, Hideaki Mitsui
  • Patent number: 6317480
    Abstract: An X-ray mask including a mask support formed into the shape of a frame, an X-ray-transparent film which is supported so as to extend over the surface of the frame-shaped mask support and which permits transmission of X-rays, and a desired X-ray-absorbing film pattern laid on the X-ray-transparent film, wherein the mask support has a thickness which by itself affords sufficient mechanical strength; and a step is formed along the periphery of the mask support.
    Type: Grant
    Filed: April 23, 1999
    Date of Patent: November 13, 2001
    Assignee: Hoya Corporation
    Inventors: Tsutomu Shoki, Akinori Kurikawa, Takamitsu Kawahara, Ryo Ohkubo