Patents by Inventor Tadahito Matsuda

Tadahito Matsuda 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: 6841334
    Abstract: Disclosed are novel onium salts represented by general formula (R)3S+M, wherein three R's may be the same or different, each being an aryl group, provided that at least one of R's is a t-alkoxy substituted phenyl group, and M is an anion capable of forming the sulfonium salts; and high energy radiation-responsive positive resist materials using said novel onium salts as acid generator.
    Type: Grant
    Filed: October 10, 2003
    Date of Patent: January 11, 2005
    Assignees: Shin-Etsu Chemical Co., Ltd., Nippon Telegraph and Telephone Corporation
    Inventors: Fujio Yagihashi, Tomoyoshi Furihata, Jun Watanabe, Akinobu Tanaka, Yoshio Kawai, Tadahito Matsuda
  • Publication number: 20040076905
    Abstract: Disclosed are novel onium salts represented by general formula (R)3S+M, wherein three R's may be the same or different, each being an aryl group, provided that at least one of R's is a t-alkoxy substituted phenyl group, and M is an anion capable of forming the sulfonium salts; and high energy radiation-responsive positive resist materials using said novel onium salts as acid generator.
    Type: Application
    Filed: October 10, 2003
    Publication date: April 22, 2004
    Inventors: Fujio Yagihashi, Tomoyoshi Furihata, Jun Watanabe, Akinobu Tanaka, Yoshio Kawai, Tadahito Matsuda
  • Patent number: 6667415
    Abstract: Disclosed are novel tert-butyl 4,4-bis(4′-hydroxyphenyl)pentanoate derivatives represented by the following general formula (I); wherein R1 represents a protective group which can be readily eliminated under an acidic condition, and R2 represents a hydrogen atom, a lower alkyl group or a lower alkoxy group: and high energy radiation-responsive positive resist materials using said novel derivatives as dissolution inhibitors.
    Type: Grant
    Filed: September 2, 1994
    Date of Patent: December 23, 2003
    Assignees: Shin-Etsu Chemical Co., Ltd., Nippon Telegraph and Telephone Corp.
    Inventors: Fujio Yagihashi, Jun Watanabe, Minoru Takamizawa, Akinobu Tanaka, Yoshio Kawai, Tadahito Matsuda
  • Patent number: 5636004
    Abstract: In a projection exposure method of irradiating illumination light from an illumination light source onto a photomask made of a transparent substrate with a periodic mask pattern, and projecting the resultant transmitted light from the photomask on a wafer through a projection system, thereby forming an optical image of the mask pattern on the wafer, projection/exposure with respect to the wafer is performed by a main exposure operation and a sub-exposure operation to be performed after the main exposure operation. The main exposure operation is performed by irradiating the photomask with the illumination light whose coherency becomes 0.3 or less when a period L of the mask pattern on the image plane of the optical system is not more than a value obtained by doubling an exposure wavelength .lambda. of the illumination light source, and dividing the resultant value by a numerical aperture of the projection system.
    Type: Grant
    Filed: August 16, 1995
    Date of Patent: June 3, 1997
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Akihiro Ootaka, Yoshio Kawai, Tadahito Matsuda
  • Patent number: 5624787
    Abstract: A chemically amplified, positive resist composition contains a trifluoromethanesulfonic or p-toluenesulfonic acid bis- or tris(p-tert-butoxyphenyl)sulfonium salt and a nitrogenous compound. The composition is highly sensitive to high energy radiation, especially KrF excimer laser and has high sensitivity, resolution and plasma etching resistance while the resulting resist pattern is heat resistant.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: April 29, 1997
    Assignees: Shin-Etsu Chemical Co., Ltd., Nippon Telegraph and Telephone Corp.
    Inventors: Satoshi Watanabe, Katsuyuki Oikawa, Toshinobu Ishihara, Akinobu Tanaka, Tadahito Matsuda, Yoshio Kawai
  • Patent number: 5414746
    Abstract: An X-ray exposure mask comprises an X-ray transmission layer and an X-ray absorption layer formed on the X-ray transmission layer and being patterned. The X-ray absorption layer has a first region having a first thickness and a second region having a second thickness less than the first thickness.
    Type: Grant
    Filed: November 1, 1993
    Date of Patent: May 9, 1995
    Assignee: Nippon Telegraph & Telephone
    Inventors: Kimiyoshi Deguchi, Yoh Somemura, Kazunori Miyoshi, Tadahito Matsuda
  • Patent number: 4808829
    Abstract: A mark position detection system used in a charged particle beam apparatus and including detection circuit for detecting a reflected electron generated at a mark when the mark is scanned with a charged particle beam, to obtain a mark signal, and signal processing circuit for comparing the mark signal from the detection circuit with a predetermined threshold level to find the position of the charged particle beam at a time the mark signal traverses the threshold level, thereby detecting the position of a mark edge, is disclosed in which, when the mark signal traverses the threshold level and has a peak value exceeding a predetermined value, it is determined by the signal processing circuit that the position of the charged particle beam at a time point at which the mark signal traverses the threshold level is the position of the mark.
    Type: Grant
    Filed: June 17, 1987
    Date of Patent: February 28, 1989
    Assignees: Hitachi Ltd., Nippon Telegraph and Telephone Corp.
    Inventors: Masahide Okumura, Takashi Matsuzaka, Genya Matsuoka, Kazumi Iwadate, Tadahito Matsuda, Ryoichi Yamaguchi
  • Patent number: 4634645
    Abstract: A resist pattern is formed on a substrate by forming a resist on a substrate and radiating an energy beam carrying predetermined pattern information onto the resist, thereby forming a recessed pattern in a surface portion of the resist so as not to extend through the resist. A flat mask layer is formed on the resist including the recessed pattern. The mask layer is uniformly etched along a direction of thickness thereof until at least a surface of the resist is exposed to allow the mask layer to remain on at least a bottom of the recessed pattern, thereby forming a mask pattern comprising the remaining residual mask layer. Finally, the resist is etched by using the mask pattern as an etching mask.
    Type: Grant
    Filed: April 9, 1985
    Date of Patent: January 6, 1987
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Tadahito Matsuda, Katsuhiro Harada, Shigeru Moriya, Tetsuyoshi Ishii
  • Patent number: 4489241
    Abstract: An exposure method with an electron beam exposure apparatus in which an electron beam is emitted onto a substrate such as a silicon wafer on which an electron-beam sensitive resist is coated, thereby directly forming or writing patterns. A substrate having thereon a number of chips are divided into blocks, which each contain a plurality of chips. Marks are provided on each of the blocks, the positions of the marks are detected and the writing exposure positions of the chips within each block are modified on the basis of the detection results. According to this invention, efficient writing exposure can be made with high accuracy.
    Type: Grant
    Filed: June 9, 1982
    Date of Patent: December 18, 1984
    Assignees: Hitachi, Ltd., Nippon Telegraph & Telephone Public Corporation
    Inventors: Tadahito Matsuda, Tsuneo Okubo, Susumu Ozasa, Norio Saitou, Haruo Yoda
  • Patent number: 4437008
    Abstract: In an electron beam control system wherein manual adjusting means is used for adjusting currents to flow through two deflection coils which serve to deflect an electron beam in directions of two, x and y axes, respectively; an electron beam control system wherein the manual adjusting means comprises a joy stick type variable resistor which can simultaneously deliver coil deflection signal components in the directions of the two axes through a single operation, and the signal components from the variable resistor are applied to the corresponding deflection coils as adjusting currents.
    Type: Grant
    Filed: April 23, 1981
    Date of Patent: March 13, 1984
    Assignees: Nippon Telegraph & Telephone Public Corporation, Hitachi, Ltd.
    Inventors: Tadahito Matsuda, Masahide Okumura, Hisatake Yokouchi, Susumu Ozasa, Yasuo Kato