Patents by Inventor Naoto Nakashima

Naoto Nakashima 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: 5008702
    Abstract: An enlargement projection type exposure method includes the steps of deforming the shape of a substrate so as to eliminate distortion in an enlarged image of the pattern, which is formed on a mask and projected onto the substrate through an enlargement projection system. The pattern is exposed with the use of an enlargement projection optical system. An apparatus for the method comprises an enlargement projection optical system for enlarging the pattern formed on the mask, and a substrate deforming device for deforming by adsorption the substrate in shape so as to eliminate the distortion in the enlarged image of the pattern through the enlargement projection optical system.
    Type: Grant
    Filed: August 31, 1989
    Date of Patent: April 16, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Tsutomu Tanaka, Yoshitada Oshida, Masataka Shiba, Naoto Nakashima, Ryuichi Funatsu
  • Patent number: 4993837
    Abstract: A method and a system for pattern detection are disclosed in which a laser beam high in directivity is emitted from a laser beam source, the laser beam emitted from the laser beam source is irradiated on an uneven pattern to be detected on an object, the light component of a frequency corresponding to the cut-off frequency of an objective lens is removed from the light reflected from the object when an image of the pattern on the object is formed through an objective lens, the optical image thus formed is received by a photoelectric converting device for producing a signal waveform representing the pattern free of a signal of the frequency corresponding to the cut-off frequency, and the pattern is detected from a signal produced from the photoelectric converting device.
    Type: Grant
    Filed: January 25, 1989
    Date of Patent: February 19, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Yoshitada Oshida, Yasuhiro Yoshitake, Naoto Nakashima, Masataka Shiba
  • Patent number: 4862008
    Abstract: A wafer is aligned by using an alignment light having a longer wavelength than an exposure light. Exposure and alignment are effected through a common reduction lens. A wavefront aberration caused by the use of the long wavelength alignment light is compensated by a hologram. Thus, an alignment precision is improved without exposing a resist layer to a light.
    Type: Grant
    Filed: June 29, 1988
    Date of Patent: August 29, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Yoshitada Oshida, Naoto Nakashima, Yasuhiro Yoshitake
  • Patent number: 4819033
    Abstract: An illumination apparatus is disclosed which is suitable for use in a projection/exposure system for projecting an image of a circuit pattern of a reticle on a semiconductor wafer through a projection lens. The illumination apparatus includes an excimer laser for emitting a pulsed laser beam, an optical system for illuminating the reticle with a plurality of laser pulses emitted from the excimer laser so that laser pulses having passed through the reticle impinge on the semiconductor wafer in different directions through the projection lens, and a light intensity control device for controlling the light intensity of each of the laser pulses so that the laser pulses equally contribute to the reaction of a light sensitive material which is provided on the semiconductor wafer, with light.
    Type: Grant
    Filed: October 28, 1987
    Date of Patent: April 4, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Yasuhiro Yoshitake, Yoshitada Oshida, Masataka Shiba, Naoto Nakashima
  • Patent number: 4779986
    Abstract: A reduction projection system alignment method for detecting the positions of an alignment pattern on a reticle and an alignment pattern on a wafer projected onto a reticle by a reduction projection lens so as to relatively align the reticle and wafer. This method comprises providing spatial images emanating from patterns on the reticle and wafer surfaces as alginment patterns of at least one of the reticle and wafer, and detecting the alignment patterns of the reticle and wafer by the same detection optical system using lights which are different in the wavelength from that of an exposure light and different from each other between the reticle and wafer. An apparatus for performing this method is also disclosed.
    Type: Grant
    Filed: April 14, 1986
    Date of Patent: October 25, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Naoto Nakashima, Yoshitada Oshida
  • Patent number: 4744666
    Abstract: In an alignment detection optical system designed to observe an alignment pattern of a mask and an image of an alignment pattern of a wafer formed on the alignment pattern of the mask by a projection lens in a projection type aligner, there is provided a spatial filter designed to select only the reflected light having a desired reflection angle from the light reflected by the alignment pattern composed of steps formed on a surface of the wafer.
    Type: Grant
    Filed: July 16, 1986
    Date of Patent: May 17, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Yoshitada Oshida, Naoto Nakashima, Toshihiko Nakata
  • Patent number: 4701050
    Abstract: A semiconductor focusing exposure apparatus in which an opposite face of a mask to a face to be illuminated by exposure light is illuminated with alignment light so that the light reflected from said opposite face may be used for alignment and which is equipped with a second moving arrangement which is separate from a moving arrangement for an x-y moving table supporting a wafer, for aligning the mask and the wafer in an orthogonal direction with respect to the optical axis of a focusing lens.Moreover, the center of the flux of alignment pattern light for illuminating the wafer is made incident upon a line of intersection on which a plane containing the optical axis of an alignment optical system and the optical axis of said focusing lens and the incident plane of said focusing lens intersect with each other.
    Type: Grant
    Filed: August 5, 1985
    Date of Patent: October 20, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Yoshitada Oshida, Masataka Shiba, Naoto Nakashima, Toshihiko Nakata, Sachio Uto
  • Patent number: 4668089
    Abstract: An exposure apparatus comprises a light source, a mask plate having an exposure pattern area section and an alignment/reflection area section, a projection lens, a movable stage for holding a workpiece having a workpiece alignment mark, an alignment control and a driver for the movable stage. Before the exposure pattern area section is illuminated by the light source to be projected through the projection lens onto the workpiece, the workpiece is properly aligned with the mask. Alignment between the mask plate and the workpiece is performed by the effective use of the alignment/reflection area section specifically arranged and having a specific structure.
    Type: Grant
    Filed: December 20, 1984
    Date of Patent: May 26, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Yoshitada Oshida, Masataka Shiba, Toshihiko Nakata, Mitsuyoshi Koizumi, Naoto Nakashima