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).
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Patent number: 6522716Abstract: 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: GrantFiled: October 6, 2000Date of Patent: February 18, 2003Assignee: Nikon CorporationInventors: Katsuhiko Murakami, Yutaka Ichihara
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Patent number: 6362926Abstract: 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: GrantFiled: November 27, 2000Date of Patent: March 26, 2002Assignee: Nikon CorporationInventors: Yasuhiro Omura, Yutaka Ichihara, Tetsuo Takahashi
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Publication number: 20010024330Abstract: 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: ApplicationFiled: February 7, 2001Publication date: September 27, 2001Inventors: Sumio Hashimoto, Yutaka Suenaga, Yutaka Ichihara
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Patent number: 6195213Abstract: 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: GrantFiled: June 8, 1999Date of Patent: February 27, 2001Assignee: Nikon CorporationInventors: Yasuhiro Omura, Tetsuo Takahashi, Masatoshi Ikeda, Shiwen Li, Yutaka Ichihara
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Patent number: 6118596Abstract: 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: GrantFiled: August 14, 1996Date of Patent: September 12, 2000Assignee: Nikon CorporationInventors: Sumio Hashimoto, Yutaka Suenaga, Yutaka Ichihara
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Patent number: 6108140Abstract: 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: GrantFiled: February 8, 1999Date of Patent: August 22, 2000Assignee: Nikon CorporationInventors: Sumio Hashimoto, Yutaka Suenaga, Yutaka Ichihara
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Patent number: 5898501Abstract: 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: GrantFiled: July 24, 1997Date of Patent: April 27, 1999Assignee: Nikon CorporationInventors: Jun Suzuki, Takashi Gemma, Yutaka Ichihara
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Patent number: 5844728Abstract: 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: GrantFiled: June 26, 1996Date of Patent: December 1, 1998Assignee: Nikon CorporationInventors: Sumio Hashimoto, Yutaka Suenaga, Yutaka Ichihara
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Patent number: 5793473Abstract: 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: GrantFiled: January 2, 1997Date of Patent: August 11, 1998Assignee: Nikon CorporationInventors: Motoo Koyama, Yutaka Ichihara
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Patent number: 5774240Abstract: 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: GrantFiled: May 16, 1995Date of Patent: June 30, 1998Assignee: Nikon CorporationInventors: Akihiro Goto, Takashi Genma, Yutaka Ichihara, Nobutaka Magome, Naomasa Shiraishi, Toshio Matsuura, Hiroshi Shirasu, Masami Ebi
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Patent number: 5712735Abstract: 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: GrantFiled: June 26, 1996Date of Patent: January 27, 1998Assignee: Nikon CorporationInventors: Sumio Hashimoto, Yutaka Suenaga, Yutaka Ichihara
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Patent number: 5623473Abstract: 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: GrantFiled: June 29, 1995Date of Patent: April 22, 1997Assignee: Nikon CorporationInventor: Yutaka Ichihara
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Patent number: 5563706Abstract: 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: GrantFiled: August 22, 1994Date of Patent: October 8, 1996Assignee: Nikon CorporationInventors: Masato Shibuya, Yutaka Ichihara, Takashi Gemma, Shuji Toyonaga, Keiji Inada
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Patent number: 5528390Abstract: An exposure apparatus for reproducing a mask pattern onto a photo-sensitive surface of a substrate using holographic techniques.Type: GrantFiled: June 5, 1995Date of Patent: June 18, 1996Assignee: Nikon CorporationInventors: Akihiro Goto, Takashi Genma, Yutaka Ichihara, Nobutaka Magome, Naomasa Shiraishi, Toshio Matsuura, Hiroshi Shirasu, Masami Ebi
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Patent number: 5504596Abstract: 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: GrantFiled: December 20, 1993Date of Patent: April 2, 1996Assignee: Nikon CorporationInventors: Akihiro Goto, Takashi Gemma, Yutaka Ichihara, Nobutaka Magome, Naomasa Shiraishi, Hiroshi Shirasu, Toshio Matsuura
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Patent number: 5446556Abstract: 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: GrantFiled: April 28, 1994Date of Patent: August 29, 1995Assignee: Nikon CorporationInventors: Yoshinori Kuroiwa, Hiroshi Nishida, Hisashi Okugawa, Yutaka Ichihara, Satoru Kumagai
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Patent number: 5307207Abstract: 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: GrantFiled: October 23, 1991Date of Patent: April 26, 1994Assignee: Nikon CorporationInventor: Yutaka Ichihara
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Patent number: 5289312Abstract: 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: GrantFiled: September 22, 1992Date of Patent: February 22, 1994Assignee: Nikon CorporationInventors: Sumio Hashimoto, Yutaka Ichihara
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Patent number: 5253110Abstract: 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: GrantFiled: November 24, 1992Date of Patent: October 12, 1993Assignee: Nikon CorporationInventors: Yutaka Ichihara, Yuji Kudo
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Patent number: RE36740Abstract: 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: GrantFiled: June 14, 1995Date of Patent: June 20, 2000Assignee: Nikon CorporationInventors: Yutaka Ichihara, Hideo Mizutani, Sumio Hashimoto, Yutaka Suenaga