Patents by Inventor Yutaka Ichihara

Yutaka Ichihara 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: 6522716
    Abstract: Microlithography apparatus and methods are disclosed for achieving high-resolution pattern transfer of a pattern onto a substrate, such as a semiconductor wafer, using extreme ultraviolet (EUV, also termed soft X-ray) radiation. The apparatus include an imaging-optical system (projection-optical system) capable of receiving pattern-encoding EUV light from a mask and forming an image of the pattern on the substrate. The desired wavelength of the EUV light is 20 nm to 50 nm, and the imaging-optical system includes multiple reflective mirrors having aspherical surficial profiles and multilayer-film reflective surfaces. The apparatus are configured especially to achieve a pattern-element resolution, of the projected image, of 70 nm or finer.
    Type: Grant
    Filed: October 6, 2000
    Date of Patent: February 18, 2003
    Assignee: Nikon Corporation
    Inventors: Katsuhiko Murakami, Yutaka Ichihara
  • Patent number: 6362926
    Abstract: The present invention relates to a projection exposure apparatus (10) for and method of imaging a reticle (R) having patterned surface onto a substrate (W) in photolithographic processes for manufacturing a variety of devices. The invention further relates to an optical system (C) having a folding member(M1) suited to the projection exposure apparatus, and a method for manufacturing the optical system. The projection exposure apparatus comprises an illumination optical system (IS) and a reticle stage (RS) capable of holding the reticle so the normal line to its patterned surface is in the direction of gravity. The apparatus also includes a substrate stage (WS) capable of holding the substrate with its surface normal parallel to the direction of gravity. The optical system includes a first imaging optical system (A) comprising a concave reflecting mirror and a dioptric optical member arranged along a first optical axis. The first imaging optical system (A) forms an intermediate image of the patterned surface.
    Type: Grant
    Filed: November 27, 2000
    Date of Patent: March 26, 2002
    Assignee: Nikon Corporation
    Inventors: Yasuhiro Omura, Yutaka Ichihara, Tetsuo Takahashi
  • Publication number: 20010024330
    Abstract: A catadioptric reduction projection optical system having a first lens unit having negative refractive power and widening a light beam from a reticle, a prism type beam splitter for transmitting therethrough a light beam from the first lens unit, a concave reflecting mirror for returning the light beam emerging from the beam splitter to the beam splitter while converging it, and a second lens unit having positive refractive power and converging the light beam returned to the beam splitter and reflected by the beam splitter, and forming the reduced image of a pattern on the reticle on a wafer.
    Type: Application
    Filed: February 7, 2001
    Publication date: September 27, 2001
    Inventors: Sumio Hashimoto, Yutaka Suenaga, Yutaka Ichihara
  • Patent number: 6195213
    Abstract: The present invention relates to a projection exposure apparatus (10) for and method of imaging a reticle (R) having patterned surface onto a substrate (W) in photolithographic processes for manufacturing a variety of devices. The invention further relates to an optical system (C) having a folding member (M1) suited to the projection exposure apparatus, and a method for manufacturing the optical system. The projection exposure apparatus comprises an illumination optical system (IS) and a reticle stage (RS) capable of holding the reticle so the normal line to its patterned surface is in the direction of gravity. The apparatus also includes a substrate stage (WS) capable of holding the substrate with its surface normal parallel to the direction of gravity. The optical system includes a first imaging optical system (A) comprising a concave reflecting mirror and a dioptric optical member arranged along a first optical axis. The first imaging optical system (A) forms an intermediate image of the patterned surface.
    Type: Grant
    Filed: June 8, 1999
    Date of Patent: February 27, 2001
    Assignee: Nikon Corporation
    Inventors: Yasuhiro Omura, Tetsuo Takahashi, Masatoshi Ikeda, Shiwen Li, Yutaka Ichihara
  • Patent number: 6118596
    Abstract: A catadioptric reduction projection optical system having a first lens unit having negative refractive power and widening a light beam from a reticle, a prism type beam splitter for transmitting therethrough a light beam from the first lens unit, a concave reflecting mirror for returning the light beam emerging from the beam splitter to the beam splitter while converging it, and a second lens unit having positive refractive power and converging the light beam returned to the beam splitter and reflected by the beam splitter, and forming the reduced image of a pattern on the reticle on a wafer.
    Type: Grant
    Filed: August 14, 1996
    Date of Patent: September 12, 2000
    Assignee: Nikon Corporation
    Inventors: Sumio Hashimoto, Yutaka Suenaga, Yutaka Ichihara
  • Patent number: 6108140
    Abstract: A catadioptric reduction projection optical system having a first lens unit having negative refractive power and widening a light beam from a reticle, a prism type beam splitter for transmitting therethrough a light beam from the first lens unit, a concave reflecting mirror for returning the light beam emerging from the beam splitter to the beam splitter while converging it, and a second lens unit having positive refractive power and converging the light beam returned to the beam splitter and reflected by the beam splitter, and forming the reduced image of a pattern on the reticle on a wafer.
    Type: Grant
    Filed: February 8, 1999
    Date of Patent: August 22, 2000
    Assignee: Nikon Corporation
    Inventors: Sumio Hashimoto, Yutaka Suenaga, Yutaka Ichihara
  • Patent number: 5898501
    Abstract: Apparatus and methods are disclosed for measuring wavefront aberrations microlithography projection lenses such as i-line or excimer laser projection lenses. The apparatus comprises an argon-ion laser irradiating a Fizeau surface that reflects reference light and transmits test light. The test light is reflected by a spherical reflecting surface to pass twice through the test lens and the Fizeau surface, to interfere with the reference light. A piezoelectric element changes the fringes slightly. An image-pickup device receives the interference fringes and outputs data to a processor that calculates corresponding wavefront aberrations of the test lens. For testing an i-line lens, the argon laser can be a single-mode, 363.8 nm laser. For testing a lens used with a KrF excimer laser, the argon laser can emit second-harmonic light at 248.25 nm.
    Type: Grant
    Filed: July 24, 1997
    Date of Patent: April 27, 1999
    Assignee: Nikon Corporation
    Inventors: Jun Suzuki, Takashi Gemma, Yutaka Ichihara
  • Patent number: 5844728
    Abstract: A catadioptric reduction projection optical system having a first lens unit having negative refractive power and widening a light beam from a reticle, a prism type beam splitter for transmitting therethrough a light beam from the first lens unit, a concave reflecting mirror for returning the light beam emerging from the beam splitter to the beam splitter while converging it, and a second lens unit having positive refractive power and converging the light beam returned to the beam splitter and reflected by the beam splitter, and forming the reduced image of a pattern on the reticle on a wafer.
    Type: Grant
    Filed: June 26, 1996
    Date of Patent: December 1, 1998
    Assignee: Nikon Corporation
    Inventors: Sumio Hashimoto, Yutaka Suenaga, Yutaka Ichihara
  • Patent number: 5793473
    Abstract: A projection exposure apparatus projects the pattern of a reticle at a high resolution even when a wafer which is poor in flatness because of its warping or step is used. An illumination light beam emitted from a light source system illuminates a reticle through a condenser lens. The illumination light beam emerging from the reticle forms the intermediate image of the pattern of the reticle at a position near the reflecting surface of a reflecting mirror through a half prism and a projection lens. The illumination light beam reflected by the reflecting surface forms the pattern image of the reticle onto the surface of a wafer after passing through the projection lens and the half prism again. The shape of the reflecting surface of the reflecting mirror is changed to conform to the shape of the surface of the wafer.
    Type: Grant
    Filed: January 2, 1997
    Date of Patent: August 11, 1998
    Assignee: Nikon Corporation
    Inventors: Motoo Koyama, Yutaka Ichihara
  • Patent number: 5774240
    Abstract: An exposure apparatus for reproducing a mask pattern onto a photo-sensitive surface of a substrate uses holographic techniques. The apparatus includes support for holding a hologram recording plate at a predetermined position during both a recording operation and a reconstructing operation. A first illuminating optical system introduces a light beam from a coherent light source to a mask and irradiates a subject beam produced from the mask into the recording plate. A second illuminating optical system irradiates the light beam from a coherent light source as a reference beam into the recording plate, a carrier apparatus disposes during the reconstructing operation, a substrate at the position of the mask, in place of the mask. A third illuminating optical system for irradiates a conjugate beam with the reference beam into the recording plate, in which a hologram has been formed by the recording operation, to form an image of the hologram on the photo-sensitive surface of the substrate.
    Type: Grant
    Filed: May 16, 1995
    Date of Patent: June 30, 1998
    Assignee: Nikon Corporation
    Inventors: Akihiro Goto, Takashi Genma, Yutaka Ichihara, Nobutaka Magome, Naomasa Shiraishi, Toshio Matsuura, Hiroshi Shirasu, Masami Ebi
  • Patent number: 5712735
    Abstract: A catadioptric reduction projection optical system having a first lens unit having negative refractive power and widening a light beam from a reticle, a prism type beam splitter for transmitting therethrough a light beam from the first lens unit, a concave reflecting mirror for returning the light beam emerging from the beam splitter to the beam splitter while converging it, and a second lens unit having positive refractive power and converging the light beam returned to the beam splitter and reflected by the beam splitter, and forming the reduced image of a pattern on the reticle on a wafer.
    Type: Grant
    Filed: June 26, 1996
    Date of Patent: January 27, 1998
    Assignee: Nikon Corporation
    Inventors: Sumio Hashimoto, Yutaka Suenaga, Yutaka Ichihara
  • Patent number: 5623473
    Abstract: An apparatus of this invention has an objective lens for guiding an exposure beam emitted by a light source toward a first region on a rotary table, a lighting light source for irradiating lighting light in the direction of the first region via the objective lens, an image pickup device for picking up an image from the first region obtained via the objective lens, modulation means for changing the propagating direction of the exposure beam, and a controller for controlling the modulation means on the basis of a signal input from the image pickup device.
    Type: Grant
    Filed: June 29, 1995
    Date of Patent: April 22, 1997
    Assignee: Nikon Corporation
    Inventor: Yutaka Ichihara
  • Patent number: 5563706
    Abstract: In an interferometer, reflected light from a reference surface and a subject surface are introduced to an imaging optical system through a beam splitter, and an interference fringe formed from light reflected from the both surfaces is observed with a detection optical system. An alignment optical member is disposed in an optical path between the imaging optical system and an image plane of the interference fringe such that the rear focal point of the alignment optical member is located at the image plane. The alignment optical member is inserted in the optical path in aligning the subject surface and is removed in measuring the interference fringe. Accurate alignment of the subject surface is easily attained. A beam expander is interposed between a polarizing beam splitter and the subject surface and a 90.degree. retarder is interposed between the beam expander and the subject surface. The 90.degree. retarder is constructed of one or a plurality of reflecting mirrors formed of dielectric multilayer films.
    Type: Grant
    Filed: August 22, 1994
    Date of Patent: October 8, 1996
    Assignee: Nikon Corporation
    Inventors: Masato Shibuya, Yutaka Ichihara, Takashi Gemma, Shuji Toyonaga, Keiji Inada
  • Patent number: 5528390
    Abstract: An exposure apparatus for reproducing a mask pattern onto a photo-sensitive surface of a substrate using holographic techniques.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: June 18, 1996
    Assignee: Nikon Corporation
    Inventors: Akihiro Goto, Takashi Genma, Yutaka Ichihara, Nobutaka Magome, Naomasa Shiraishi, Toshio Matsuura, Hiroshi Shirasu, Masami Ebi
  • Patent number: 5504596
    Abstract: An exposure apparatus is used for reproducing a mask pattern of a semiconductor device or the like onto a photosensitive substrate using a holography. The holography is utilized also in a process for alignment between a mask pattern hologram and an exposure region of the substrate. The pattern hologram is recorded to a recording medium by interference between an object wave from the pattern and a reference wave, and a second hologram is formed to the medium by diffraction light from an alignment mark formed on the mask. Prior to reconstruction of the pattern image, reconstruction light from the second hologram, illuminated with a reconstruction wave, is irradiated onto the substrate arranged in place of the mask. A reproduction image of the alignment mark on the substrate surface illuminated with the reconstruction light is measured, and relative displacement between the medium and the substrate is detected from a result of the measurement.
    Type: Grant
    Filed: December 20, 1993
    Date of Patent: April 2, 1996
    Assignee: Nikon Corporation
    Inventors: Akihiro Goto, Takashi Gemma, Yutaka Ichihara, Nobutaka Magome, Naomasa Shiraishi, Hiroshi Shirasu, Toshio Matsuura
  • Patent number: 5446556
    Abstract: A video clock signal generator comprises: means for supplying a light beam; a mask having opposite ends spaced by a predetermined distance; a vibration scanner for reflecting the light beam and forming a light spot vibrating on the mask beyond the opposite ends thereof; a detector for generating an output signal representing optical information from the mask; a counter for counting a time required for the light spot to cross the opposite ends of the mask based on the output signal of the detector; and a control unit for controlling an amplitude of the scanner mirror in accordance with the time counted by the counter.
    Type: Grant
    Filed: April 28, 1994
    Date of Patent: August 29, 1995
    Assignee: Nikon Corporation
    Inventors: Yoshinori Kuroiwa, Hiroshi Nishida, Hisashi Okugawa, Yutaka Ichihara, Satoru Kumagai
  • Patent number: 5307207
    Abstract: An illuminating optical apparatus comprises a stable resonator type laser equipped with a wavelength selecting element and a device for vibrating the beam one-dimensionally in a direction crossing the longer direction of the beam cross section at at least one of the entrance side and exit side of a fly's eye lens or optical integrator.
    Type: Grant
    Filed: October 23, 1991
    Date of Patent: April 26, 1994
    Assignee: Nikon Corporation
    Inventor: Yutaka Ichihara
  • Patent number: 5289312
    Abstract: A catadioptric reduction projection optical system is of a construction in which an on-axis light beam is used in a catadioptric system, and is designed such that resolving power is not deteriorated and a stop can be disposed.
    Type: Grant
    Filed: September 22, 1992
    Date of Patent: February 22, 1994
    Assignee: Nikon Corporation
    Inventors: Sumio Hashimoto, Yutaka Ichihara
  • Patent number: 5253110
    Abstract: An illumination optical arrangement which uses a laser light source to produce a uniform illumination which is high in brightness and substantially free of interference patterns. The illumination optical arrangement includes light source means for emitting a coherent light beam, optical illuminance distribution uniformizing means for making substantially uniform the intensity distribution in a beam cross-section of illumination by the coherent light beam on a plane to be illuminated, and optical polarizing means for producing from the coherent light beam a plurality of polarized light components which are different in polarized state from each other in such a manner that wavefronts of incident light beams of the polarized light components to the optical illuminance distribution uniformizing means are inclined relative to each other whereby interference patterns produced by the polarized light components are relatively shifted in position in the illuminated plane.
    Type: Grant
    Filed: November 24, 1992
    Date of Patent: October 12, 1993
    Assignee: Nikon Corporation
    Inventors: Yutaka Ichihara, Yuji Kudo
  • Patent number: RE36740
    Abstract: In a cata-dioptric optical system having a combination of a reflection system and a refraction system for reduction-projecting an object on a first plane onto a second plane, a polarization beam splitter and a quarter wavelength plate are provided to split the incident light and the reflected light. The light beam directed to the polarization beam splitter is converted to a substantially collimated light beam by a first group of lenses. A second group of lenses are arranged between the polarization beam splitter and a concave reflection mirror to diverge the light beam. The light reflected by the concave reflection mirror is directed back to the polarization beam splitter with a substantially collimated state by the second group of lenses. The light beam from the second group of lenses transmitted through the polarization beam splitter is focused by a third group of lenses having a positive refraction power to form a reduced image.
    Type: Grant
    Filed: June 14, 1995
    Date of Patent: June 20, 2000
    Assignee: Nikon Corporation
    Inventors: Yutaka Ichihara, Hideo Mizutani, Sumio Hashimoto, Yutaka Suenaga