Patents by Inventor Shohei Mimura

Shohei Mimura 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: 20230367199
    Abstract: A reflective photomask blank includes a substrate, a multilayer reflection film that reflects exposure light being light in extreme ultraviolet range, a protection film, a light-absorbing film that absorbs the exposure light, and a hard mask film that is formed in contact with the light-absorbing film. The hard mask film is constituted by a multilayer including a first layer disposed at the side remotest from the substrate, and is composed of a material that is resistant to chlorine-based dry etching, and removable by fluorine-based dry etching, and a second layer composed of a material that is resistant to fluorine-based dry etching, and removable by chlorine-based dry etching. An etching clear time of the light-absorbing film on fluorine-based dry etching under one condition is longer than an etching clear time of the first layer on the fluorine-based dry etching under the same condition.
    Type: Application
    Filed: April 27, 2023
    Publication date: November 16, 2023
    Applicant: Shin-Etsu Chemical Co., Ltd.
    Inventors: Keisuke SAKURAI, Shohei MIMURA, Takeshi ISHII
  • Publication number: 20230333460
    Abstract: A reflective photomask blank includes a substrate, a multilayer reflection film that is formed on the substrate and reflects exposure light being light in extreme ultraviolet range, a protection film that is formed on the multilayer reflection film to protect the multilayer reflection film, a light-absorbing film that is formed on the protection film and absorbs the exposure light, and a hard mask film that is formed on and in contact with the light-absorbing film and functions as a hard mask in pattering the light-absorbing film by dry etching. The hard mask film is constituted by a multilayer including a first layer and a second layer, the first layer is disposed at the side remotest from the substrate, and is composed of a material containing silicon and free of chromium, and the second layer is composed of a material containing chromium and free of silicon.
    Type: Application
    Filed: March 23, 2023
    Publication date: October 19, 2023
    Applicant: Shin-Etsu Chemical Co., Ltd.
    Inventors: Keisuke SAKURAI, Shohei MIMURA, Takeshi ISHII
  • Publication number: 20220283492
    Abstract: A reflective mask blank that is a material for a reflective mask used in EUV lithography using EUV light as exposure light, including a substrate, a multilayer reflection film that is formed on one main surface of the substrate and reflects the exposure light, and an absorber film containing tungsten, and another metal, a metalloid or a light element that is formed on the multilayer reflection film and absorbs the exposure light.
    Type: Application
    Filed: February 11, 2022
    Publication date: September 8, 2022
    Applicant: Shin-Etsu Chemical Co., Ltd.
    Inventors: Shohei MIMURA, Hideo KANEKO, Tsuneo TERASAWA
  • Publication number: 20220283491
    Abstract: Metal and metalloid elements for an absorber film of a reflective mask blank are selected from first, second and third elements included in first, second and third regions, respectively, that are defined by a refractive index n and an extinction coefficient k of a simple substance of each of the metal and metalloid elements, and the absorber film is formed so as to have a reflectance ratio of 0.05 to 0.25, and a phase shift of 180 to 260° by the selected metal and metalloid elements.
    Type: Application
    Filed: February 11, 2022
    Publication date: September 8, 2022
    Applicant: SHIN-ETSU CHEMICAL CO., LTD.
    Inventors: Tsuneo TERASAWA, Hideo KANEKO, Shohei MIMURA
  • Patent number: 11422456
    Abstract: A phase shift mask blank has a transparent substrate and a phase shift film formed on the transparent substrate. The phase shift film has a phase difference of 160 to 200° and a transmittance of 3 to 15% at exposure wavelength of 200 nm or less and includes a lower layer and an upper layer in order from the transparent substrate side. The upper layer contains transition metal, silicon, nitrogen and/or oxygen, or silicon, nitrogen and/or oxygen. The lower layer contains chromium, silicon, nitrogen and/or oxygen, and the content of silicon is 3% or more to less than 15% for the sum of chromium and silicon in the lower layer. The ratio of oxygen content to the total content of chromium and silicon is less than 1.7, and etching selectivity of the upper layer is 10 or more compared to the lower layer in fluorine-based dry etching.
    Type: Grant
    Filed: August 31, 2021
    Date of Patent: August 23, 2022
    Assignee: SHIN-ETSU CHEMICAL CO., LTD.
    Inventors: Takuro Kosaka, Naoki Matsuhashi, Shohei Mimura
  • Publication number: 20220137502
    Abstract: A phase shift mask blank including a transparent substrate, an etching protection film formed on the transparent substrate, and a phase shift film formed in contact with the etching protection film, for exposure light being ArF excimer laser. The etching protection film is composed of a material containing hafnium and oxygen or hafnium, silicon and oxygen, and has a thickness of 1 to 30 nm, and a transmittance of not less than 85% with respect the exposure light, and the phase shift film is composed of a material containing silicon and being free of hafnium, and has a thickness of 50 to 90 nm.
    Type: Application
    Filed: October 15, 2021
    Publication date: May 5, 2022
    Applicant: Shin-Etsu Chemical Co., Ltd.
    Inventors: Shohei MIMURA, Naoki MATSUHASHI, Takuro KOSAKA
  • Publication number: 20220082929
    Abstract: A phase shift mask blank has a transparent substrate and a phase shift film formed on the transparent substrate. The phase shift film has a phase difference of 160 to 200° and a transmittance of 3 to 15% at exposure wavelength of 200 nm or less and includes a lower layer and an upper layer in order from the transparent substrate side. The upper layer contains transition metal, silicon, nitrogen and/or oxygen, or silicon, nitrogen and/or oxygen. The lower layer contains chromium, silicon, nitrogen and/or oxygen, and the content of silicon is 3% or more to less than 15% for the sum of chromium and silicon in the lower layer. The ratio of oxygen content to the total content of chromium and silicon is less than 1.7, and etching selectivity of the upper layer is 10 or more compared to the lower layer in fluorine-based dry etching.
    Type: Application
    Filed: August 31, 2021
    Publication date: March 17, 2022
    Applicant: SHIN-ETSU CHEMICAL CO., LTD.
    Inventors: Takuro Kosaka, Naoki Matsuhashi, Shohei Mimura
  • Publication number: 20210318607
    Abstract: A reflective mask blank that is a material for a reflective mask used in EUV lithography using EUV light as the exposure light, including a substrate, a multilayer reflection film that is formed on one main surface of the substrate and reflects the exposure light, and an absorber film that is formed on the multilayer reflection film and absorbs the exposure light, the absorber film being a single layer consisting of a first layer, or a plurality of layers consisting of, from the substrate side, a first layer and a second layer, the first layer being composed of tantalum and nitrogen and containing 55 to 70 at % of tantalum and 30 to 45 at % of nitrogen, the second layer being composed of tantalum and nitrogen, and oxygen of not more than 40 at %.
    Type: Application
    Filed: March 22, 2021
    Publication date: October 14, 2021
    Applicant: Shin-Etsu Chemical Co., Ltd.
    Inventors: Takuro KOSAKA, Shohei MIMURA, Takuro YAMAMOTO, Yukio INAZUKI
  • Patent number: 6310837
    Abstract: The invention is a magnetic recording medium which is effectively protected against forgery by the alteration of recorded data, and a method for carrying out writing and reading on this magnetic recording medium. The magnetic recording medium of the invention comprises a recording material composed of a crystalline alloy containing Fe and Al . In the recoding material, the total amount of Fe and Al is at least 90 at % and the atomic ratio Al/(Fe+Al) ranges from 0.30 to 0.45. The recording material changes from a disordered phase to an ordered phase by heating. The recording material has a saturation magnetization of at least 45 emu/g prior to heating and lowers its saturation magnetization by at least 35 emu/g upon heating. Dark regions are observable in a bright-field image of the recording material by transmission electron microscopy, the dark regions accounting for 15-60% of the recording material in areal ratio and having a maximum breadth of 10-200 nm.
    Type: Grant
    Filed: October 13, 1998
    Date of Patent: October 30, 2001
    Assignees: TDK Corporation, Tokyo Magnetic Printing Co., Ltd.
    Inventors: Tsutomu Chou, Masao Shigeta, Masahiro Karatsu, Mari Fujii, Chikara Ishizaka, Katsumi Saito, Katsuhiko Wakayama, Shohei Mimura, Masahiro Ito
  • Patent number: 6202926
    Abstract: A magnetic recording medium, and methods of making and reading the same, including on at least a portion of a substrate an irreversible recording layer which contains an irreversible recording material undergoing an irreversible change of saturation magnetization upon heating. The invention involves the steps of previously heating the irreversible recording layer to form an initial heated region in which a plurality of heated bars whose saturation magnetization has been irreversibly changed are arrayed in a bar code pattern, and converting unheated bars disposed between the heated bars into a heated state for changing the array pattern of heated bars, thereby recording the information.
    Type: Grant
    Filed: February 4, 1999
    Date of Patent: March 20, 2001
    Assignees: Tokyo Magnetic Printing Co., Ltd., TDK Corporation
    Inventors: Masahiro Ito, Shohei Mimura, Masao Shigeta, Tsutomu Chou
  • Patent number: 6029895
    Abstract: A magnetic recording medium, and a method of making the same, including an irreversible recording layer which undergoes an irreversible change of saturation magnetization upon heating. The magnetic recording medium includes on at least a portion of a substrate an irreversible recording layer which contains an irreversible recording material undergoing an irreversible change of saturation magnetization upon heating. The irreversible recording layer includes at least in part a fixed information recording region for recording the fixed information of the medium. In the fixed information recording region, a plurality of heated bars whose saturation magnetization has been irreversibly changed are arrayed substantially parallel to each other. The array pattern of the heated bars or the array pattern of unheated bars disposed between adjacent ones of the heated bars contains the fixed information encoded in a frequency modulation process or phase modulation process.
    Type: Grant
    Filed: February 4, 1999
    Date of Patent: February 29, 2000
    Assignees: Tokyo Magnetic Printing Co., Ltd., TDK Corporation
    Inventors: Masahiro Ito, Shohei Mimura, Masao Shigeta, Tsutomu Chou
  • Patent number: 5229219
    Abstract: According to the invention, a magnetic recording medium is formed by using magnetic powder having a composition of the following formula:MeO.multidot.n[Fe.sub.2-x-y-z Ga.sub.x Cr.sub.y Al.sub.z O.sub.3 ]wherein Me is at least on element selected from the group consisting of Ba, Sr, Pb, and Ca,4.5.ltoreq.n.ltoreq.6, x.gtoreq.0, y.gtoreq.0, z.gtoreq.0,x/3+y/4+z/6.gtoreq.1/6, andx/6+y/10+z/11.ltoreq.1/6,preferably the number of those particles having a particle size of from 0.5d to 1.5d being at least 65% of the entire particles wherein is an average particle size, and the Fe content on the particle surface being substantially equal to the Fe content in the particle interior, and blending the powder with a binder. Thermomagnetic recording and thermomagnetic duplication are carried out using the medium. There results a magnetic layer which has high Hc, is not easily erased once recorded, has high squareness ratio, and enables thermomagnetic recording and thermomagnetic duplication at 100.degree. to 180.degree. C.
    Type: Grant
    Filed: July 9, 1990
    Date of Patent: July 20, 1993
    Assignee: TDK Corporation
    Inventors: Hideharu Moro, Shigeo Satoh, Osamu Kohmoto, Tetsuhito Yoneyama, Shohei Mimura, Haruyuki Takahashi, Atsushi Makimura
  • Patent number: 4923533
    Abstract: A powder comprising flakes of magnetically soft amorphous alloy having an average thickness of 0.01-1 .mu.m and an aspect ratio of 10-10,000 is blended with a binder to form a coating composition from which a magnetic shield is fabricated. The alloy is basically an Fe-B-Si ternary alloy in which iron may be partially replaced by another metal.
    Type: Grant
    Filed: July 29, 1988
    Date of Patent: May 8, 1990
    Assignees: TDK Corporation, Tokyo Magnetic Printing Company, Ltd.
    Inventors: Masao Shigeta, Tsutomu Choh, Hiroyoshi Shimizu, Ippo Hirai, Shohei Mimura, Atsushi Makimura, Hiroshi Hosaka