Patents by Inventor Akira Fujimura

Akira Fujimura 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: 20110159435
    Abstract: In the field of semiconductor production using charged particle beam lithography, a method and system for fracturing or mask data preparation or proximity effect correction is disclosed, in which the union of shots from one of a plurality of exposure passes is different than the union of shots from a different exposure pass. Methods for manufacturing a reticle and for manufacturing an integrated circuit are also disclosed, in which the union of shots from one of a plurality of charged particle beam exposure passes is different than the union of shots from a different exposure pass.
    Type: Application
    Filed: December 26, 2009
    Publication date: June 30, 2011
    Applicant: D2S, Inc.
    Inventors: Harold Robert Zable, Akira Fujimura
  • Publication number: 20110159436
    Abstract: In the field of semiconductor production using charged particle beam lithography, a method and system for fracturing or mask data preparation or proximity effect correction is disclosed, wherein a plurality of exposure passes are used, and where the sum of the base dosage levels for all of the exposure passes does not equal a normal dosage. Methods for manufacturing a reticle and manufacturing an integrated circuit are also disclosed, wherein a plurality of charged particle beam exposure passes are used, and where the sum of the base dosage levels for all of the exposure passes is different than a normal dosage.
    Type: Application
    Filed: December 26, 2009
    Publication date: June 30, 2011
    Applicant: D2S, Inc.
    Inventors: Harold Robert Zable, Akira Fujimura
  • Patent number: 7950858
    Abstract: A vehicle wheel bearing apparatus has an outer member formed with a body mounting flange on its outer circumferential surface. The body mounting flange is to be mounted on a knuckle of the vehicle. The outer member inner circumference includes double row outer raceway surfaces. An inner member includes a wheel hub with a wheel mounting flange formed on one end. A cylindrical portion extends from the wheel mounting flange. At least one inner ring is press-fit onto the cylindrical portion of the wheel hub. The inner ring outer circumference is formed with an inner raceway surface arranged opposite to the double row outer raceway surfaces. Double row rolling elements are freely rollably contained between the outer raceway surfaces and inner raceway surfaces of the outer member and the inner members. Seals are mounted within annular openings formed between the outer member and the inner member. The inner ring is axially secured relative to the wheel hub by a caulked portion.
    Type: Grant
    Filed: September 5, 2008
    Date of Patent: May 31, 2011
    Assignee: NTN Corporation
    Inventors: Takayuki Norimatsu, Akira Fujimura, Isao Hirai, Shinji Morita
  • Publication number: 20110104594
    Abstract: A method is disclosed in which a plurality of variable shaped beam (VSB) shots is used to form a desired pattern on a surface. In this method some shots within the plurality of shots overlap each other. Additionally, the union of any subset of the plurality of shots differ from the desired pattern. In some embodiments, dosages of the shots vary with respect to each other. In other embodiments, an optimization technique may be used to minimize shot count. In yet other embodiments, the plurality of shots may be optionally selected from one or more pre-computed VSB shots or groups of VSB shots. The method of the present disclosure may be used, for example, in the process of manufacturing an integrated circuit by optical lithography using a reticle, or in the process of manufacturing an integrated circuit using direct write.
    Type: Application
    Filed: January 10, 2011
    Publication date: May 5, 2011
    Applicant: D2S, INC.
    Inventors: Akira Fujimura, Lance Glasser
  • Publication number: 20110089344
    Abstract: In the field of semiconductor production using shaped charged particle beam lithography, a method and system for fracturing or mask data preparation or proximity effect correction is disclosed, wherein a shot determined for a shaped charged particle beam writer system comprises dragging the charged particle beam across a surface during the shot, so as to form a complex pattern in a single, extended shot. The dragging may be done with either variable shaped beam (VSB) or character projection (CP) shots. Methods for specifying in the shot data the path for the dragged shot are also disclosed. Other embodiments include using dragged shots with partial projection, varying the dragging velocity during a shot, and combining dragged shots with conventional shots. A method and system for creating glyphs which contain dragged shots is also disclosed.
    Type: Application
    Filed: October 21, 2009
    Publication date: April 21, 2011
    Applicant: D2S, INC.
    Inventors: Akira Fujimura, Harold Robert Zable, Michael Tucker
  • Publication number: 20110089345
    Abstract: In the field of semiconductor production using shaped beam charged particle beam lithography, a pattern is formed on a surface by dragging a charged particle beam across the surface in a single extended shot to form a track. In some embodiments, the track may form a straight path, a curved path, or a perimeter of a curvilinear shape. In other embodiments, the width of the track may be altered by varying the velocity of the dragged beam. The techniques may be used for manufacturing an integrated circuit by dragging a charged particle beam across a resist-coated wafer to transfer a pattern to the wafer, or by dragging a charged particle beam across a reticle, where the reticle is used to manufacture a photomask which is then used to transfer a pattern to a wafer using an optical lithographic process.
    Type: Application
    Filed: October 5, 2010
    Publication date: April 21, 2011
    Applicant: D2S, INC.
    Inventors: Takashi Komagata, Akira Fujimura, Harold Robert Zable, Michael Tucker
  • Patent number: 7914954
    Abstract: Stencil masks, particle beam lithography characters and methods for designing the same for use in particle beam lithography are disclosed. The masks, characters and methods for designing them allows for more accurately writing images by reducing various chemical and physical effects, particularly Coulomb and proximity effects. Particle current reaching a surface is reduced by introducing shield areas, which preserve the shape and fidelity of the written image. The shape of the written image is further corrected by systematically adjusting the shape of the character or mask.
    Type: Grant
    Filed: September 9, 2008
    Date of Patent: March 29, 2011
    Assignee: D2S, Inc.
    Inventors: Akira Fujimura, Takashi Mitsuhashi, Katsuo Komuro
  • Patent number: 7901845
    Abstract: A method for optical proximity correction of a design of a pattern on a surface is disclosed with the method comprising the steps of inputting desired patterns for the substrate and inputting a set of characters some of which are complex characters that may be used for forming the patterns on the surface. A method of creating glyphs is also disclosed.
    Type: Grant
    Filed: September 1, 2008
    Date of Patent: March 8, 2011
    Assignee: D2S, Inc.
    Inventors: Akira Fujimura, Lance Glasser, Takashi Mitsuhashi, Kazuyuki Hagiwara
  • Patent number: 7901850
    Abstract: A method for fracturing or mask data preparation or proximity effect correction of a desired pattern to be formed on a reticle is disclosed in which a plurality of variable shaped beam (VSB) shots are determined which can form the desired pattern. Shots within the plurality of VSB shots are allowed to overlap each other. Dosages of the shots may also be allowed to vary with respect to each other. The union of the plurality of shots may deviate from the desired pattern. The plurality of shots may be determined such that a pattern on the surface calculated from the plurality of shots is within a predetermined tolerance of the desired pattern. In some embodiments, an optimization technique may be used to minimize shot count. In other embodiments, the plurality of shots may be optionally selected from one or more pre-computed VSB shots or groups of VSB shots.
    Type: Grant
    Filed: May 27, 2009
    Date of Patent: March 8, 2011
    Assignee: D2S, Inc.
    Inventors: Akira Fujimura, Lance Glasser
  • Publication number: 20110053093
    Abstract: A charged particle beam writer system is disclosed comprising a generator for a charged particle beam having a beam blur radius, wherein the beam blur radius may be varied from shot to shot, or between two or more groups of shots. A method for fracturing or mask data preparation or optical proximity correction is also disclosed comprising assigning a beam blur radius variation to each calculated charged particle beam writer shot. A method for forming a pattern on a surface is also disclosed comprising using a charged particle beam writer system and varying the beam blur radius from shot to shot. A method for manufacturing an integrated circuit using optical lithography is also disclosed, comprising using a charged particle beam writer system to form a pattern on a reticle, and varying the beam blur radius of the charged particle beam writer system from shot to shot.
    Type: Application
    Filed: August 24, 2010
    Publication date: March 3, 2011
    Applicant: D2S, INC.
    Inventors: Kazuyuki Hagiwara, Akira Fujimura
  • Publication number: 20110053056
    Abstract: In the field of semiconductor production using shaped charged particle beam lithography, a method and system for fracturing or mask data preparation or proximity effect correction is disclosed, wherein a series of curvilinear character projection shots are determined for a charged particle beam writer system, such that the set of shots can form a continuous track, possibly of varying width, on a surface. A method for forming a continuous track on a surface using a series of curvilinear character projection shots is also disclosed. Methods for manufacturing a reticle and for manufacturing a substrate such as a silicon wafer by forming a continuous track on a surface using a series of curvilinear character projection shots is also disclosed.
    Type: Application
    Filed: November 14, 2009
    Publication date: March 3, 2011
    Applicant: D2S, Inc.
    Inventors: Akira Fujimura, Michael Tucker
  • Patent number: 7897522
    Abstract: A method for particle beam lithography, such as electron beam (EB) lithography, includes forming a plurality of cell patterns on a stencil mask and shaping one or more of the cell patterns with a polygonal-shaped contour. A first polygonal-shaped cell pattern is exposed to a particle beam so as to project the first polygonal-shaped cell pattern on a substrate. A second polygonal-shaped cell pattern, having a contour that mates with the contour of the first polygonal-shaped cell pattern, is exposed to the particle beam, such as an electron beam, so as to project the second polygonal-shaped cell pattern adjacent to the first polygonal-shaped cell pattern to thereby form a combined cell with the contour of the first polygonal-shaped cell pattern mated to the contour of the second polygonal-shaped cell pattern. The polygonal-shaped contour of the first and second cell patterns may comprise a rectilinear-shaped contour.
    Type: Grant
    Filed: November 21, 2006
    Date of Patent: March 1, 2011
    Assignee: Cadence Design Systems, Inc.
    Inventors: Akira Fujimura, James Fong, Takashi Mitsuhashi, Shohei Matsushita
  • Publication number: 20110045409
    Abstract: A character projection charged particle beam writer system is disclosed comprising a variable magnification reduction lens which will allow different shot magnifications on a shot by shot basis. A method for fracturing or mask data preparation or optical proximity correction is also disclosed comprising assigning a magnification to each calculated charged particle beam writer shot. A method for forming a pattern on a surface is also disclosed comprising using a charged particle beam writer system and varying the magnification from shot to shot. A method for manufacturing an integrated circuit using optical lithography is also disclosed, comprising using a charged particle beam writer system to form a pattern on a reticle, and varying the magnification of the charged particle beam writer system from shot to shot.
    Type: Application
    Filed: August 20, 2010
    Publication date: February 24, 2011
    Applicant: D2S, INC.
    Inventor: Akira Fujimura
  • Patent number: 7883272
    Abstract: A wheel support bearing assembly includes an inner member having a hub axle and an inner race mounted on the hub axle. This bearing assembly includes one of an engagement recess formed in a portion of an inner peripheral surface of the inner race corresponding to an inboard edge portion of the hub axle and an engagement projection is formed in the hub axle for engagement with the engagement recess, and an annular recess formed in the outer peripheral surface of the hub axle and is opposed to an inboard side face of the inner race by the radially outward deformation of an inboard edge portion of the hub axle.
    Type: Grant
    Filed: September 12, 2005
    Date of Patent: February 8, 2011
    Assignee: NTN Corporation
    Inventors: Masahiro Kiuchi, Kazuo Komori, Syougo Suzuki, Akira Fujimura, Takayasu Takubo
  • Patent number: 7874734
    Abstract: To provide a wheel support bearing assembly, in which the sufficient proof strength of an inner race during assemblage onto the vehicle body can be secured without its function being lowered, the wheel support bearing assembly includes an outer member, an inner member, and rows of rolling elements interposed therebetween. The inner member includes an hub axle having a flange and an inner race on an inner race mount, with raceways defined in the hub axle and the inner race. The inner race has a counterbore at its inboard end. The hub axle has a plastically deformed portion which engages an axially oriented surface of the counterbore when radially outwardly crimped and does not protrude outwardly beyond an inboard end face of the inner race. The difference P between the inner race mount and an outer peripheral face of the plastically deformed portion is 0.13 mm or more.
    Type: Grant
    Filed: June 1, 2006
    Date of Patent: January 25, 2011
    Assignee: NTN Corporation
    Inventors: Kazuo Komori, Kazunori Kubota, Hiroshi Matsunaga, Akira Fujimura, Tetsuya Hashimoto, Jun Numamoto, Masahiro Kiuchi
  • Publication number: 20100278468
    Abstract: A support bearing assembly includes a plural rows of rolling elements (5) between opposed raceway surfaces (3, 4) of outer and inner members (1, 2), respectively. The inner member (2) is formed from a hub unit (9) and an inner ring (10) mounted on an outer periphery of an inboard end portion thereof. An annular stepped area (16) is provided in an inner periphery of the inboard side of the inner ring. A crimped portion (9b) engageable with the stepped area (16) is provided on an inboard end of the hub unit (9) and has a cylindrical shape prior to a crimping process. By setting the amount of change in an inner diameter of the inboard end of the crimped portion (9b) within a preset range when a crimping punch is driven in, the amount (D) of radially outward augmentation of the crimped portion is regulated.
    Type: Application
    Filed: January 15, 2008
    Publication date: November 4, 2010
    Inventors: Akira Fujimura, Kazuo Komori, Kazunori Kubota, Tetsuya Hashimoto, Keiji Saitou
  • Patent number: 7824828
    Abstract: A method and system for dose correction of a particle beam writer is disclosed. The method and system includes reading a file of writing objects that includes dose intensity, calculating a rate of dose intensity change between adjacent writing objects, selecting a writing object that may need accuracy improvement of dose correction based on the rate of dose intensity change, and improving accuracy of the dose correction of the writing object that is selected and its adjacent objects.
    Type: Grant
    Filed: February 22, 2007
    Date of Patent: November 2, 2010
    Assignee: Cadence Design Systems, Inc.
    Inventors: Akira Fujimura, Daisuke Hara, Katsuo Komuro, Takashi Mitsuhashi
  • Patent number: 7799489
    Abstract: A method is disclosed for using non-overlapping variable shaped beam (VSB) shots in the design and manufacture of a reticle, where the union of the plurality of shots deviates from the desired pattern. Methods are described for fracturing or mask data preparation or proximity effect correction of a desired pattern to be formed on a reticle; for forming a pattern on a reticle using charged particle beam lithography; and for optical proximity correction (OPC) of a desired pattern. Dosages of the shots may be allowed to vary with respect to each other. The plurality of shots may be determined such that a pattern on the surface calculated from the plurality of shots is within a predetermined tolerance of the desired pattern. In some embodiments, an optimization technique may be used to minimize shot count.
    Type: Grant
    Filed: August 12, 2009
    Date of Patent: September 21, 2010
    Assignee: D2S, Inc.
    Inventors: Akira Fujimura, Michael Tucker
  • Publication number: 20100213982
    Abstract: The present invention introduces methods, systems, and architectures for routing clock signals in an integrated circuit layout. The introduced clock signal clock signal structures are rendered with non Manhattan routing. In a first embodiment, the traditional recursive H clock signal structure is rendered after transforming the coordinates system such that a rotated recursive H clock signal structure is rendered. In another embodiment, a recursive Y structure is used to create a clock signal structure. The recursive Y structure may also be implemented in a rotated alignment. For clock signal redundancy, non Manhattan wiring may be used to create a clock signal mesh network.
    Type: Application
    Filed: May 3, 2010
    Publication date: August 26, 2010
    Inventors: Steven Teig, Raghu Chalasani, Akira Fujimura
  • Patent number: 7772575
    Abstract: A method and system for particle beam lithography, such as electron beam (EB) lithography, is disclosed. The method and system include selecting one of a plurality of cell patterns from a stencil mask and partially exposing the cell pattern to a particle beam, such as an electron beam, so as to selectively project a portion of the cell pattern on a substrate.
    Type: Grant
    Filed: November 21, 2006
    Date of Patent: August 10, 2010
    Assignee: D2S, Inc.
    Inventors: Kenji Yoshida, Takashi Mitsuhashi, Shohei Matsushita, Akira Fujimura