Patents by Inventor Tadao Yasuzato

Tadao Yasuzato 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: 9209245
    Abstract: A photomask has a mask blank and a light shielding film formed on the mask blank. The light shielding film includes a plurality of opening traces extending in a first direction. An end of a first opening trace in the first direction and an end of a second opening trace in the first direction are in different positions in the first direction. The second opening trace adjoins the first opening trace.
    Type: Grant
    Filed: February 13, 2015
    Date of Patent: December 8, 2015
    Assignee: PS4 Luxco S.a.r.l.
    Inventor: Tadao Yasuzato
  • Publication number: 20150162402
    Abstract: A photomask has a mask blank and a light shielding film formed on the mask blank. The light shielding film includes a plurality of opening traces extending in a first direction. An end of a first opening trace in the first direction and an end of a second opening trace in the first direction are in different positions in the first direction. The second opening trace adjoins the first opening trace.
    Type: Application
    Filed: February 13, 2015
    Publication date: June 11, 2015
    Inventor: Tadao YASUZATO
  • Patent number: 8994151
    Abstract: A photomask has a mask blank and a light shielding film formed on the mask blank. The light shielding film includes a plurality of opening traces extending in a first direction. An end of a first opening trace in the first direction and an end of a second opening trace in the first direction are in different positions in the first direction. The second opening trace adjoins the first opening trace.
    Type: Grant
    Filed: May 22, 2013
    Date of Patent: March 31, 2015
    Assignee: PS4 Luxco S.A.R.L.
    Inventor: Tadao Yasuzato
  • Publication number: 20130320507
    Abstract: A photomask has a mask blank and a light shielding film formed on the mask blank. The light shielding film includes a plurality of opening traces extending in a first direction. An end of a first opening trace in the first direction and an end of a second opening trace in the first direction are in different positions in the first direction. The second opening trace adjoins the first opening trace.
    Type: Application
    Filed: May 22, 2013
    Publication date: December 5, 2013
    Applicant: Elpida Memory, Inc.
    Inventor: Tadao YASUZATO
  • Patent number: 7955761
    Abstract: An exposure mask has a rectangular pattern, an auxiliary pattern, a translucent region, and a shielding region. The rectangular pattern includes a transparent region having a dimension equal to or greater than a critical resolution of exposure light. The auxiliary pattern is arranged around the rectangular pattern and includes a transparent region having a dimension smaller than the critical resolution. The translucent region is arranged between the rectangular pattern and the auxiliary pattern for shifting a phase of light transmitted through the rectangular pattern and the auxiliary pattern to an opposite phase. The shielding region is arranged around the auxiliary pattern.
    Type: Grant
    Filed: September 18, 2008
    Date of Patent: June 7, 2011
    Assignee: Elpida Memory, Inc
    Inventor: Tadao Yasuzato
  • Patent number: 7923179
    Abstract: An exposure mask is constituted of hole-patterns whose scales are higher than the limit resolution of exposure light and which are repetitively aligned in X-Y directions with the prescribed pitch (ranging from 140 nm to 180 nm) therebetween, halftone phase shift regions whose transmission factors range from 2% to 20% and each of which is aligned between two hole-patterns adjacently lying in the X-direction or the Y-direction so as to apply an inverse phase to incidence light, and light preventive regions each of which is aligned between two hole-patterns adjacently lying in an oblique direction inclined to the X-direction or Y-direction by 45°. The exposure mask is illuminated with azimuthal polarization light which is produced by a secondary light source of a zonal illumination and whose polarization direction is perpendicular to the radial direction of the secondary light source.
    Type: Grant
    Filed: February 5, 2009
    Date of Patent: April 12, 2011
    Assignee: Elpida Memory Inc.
    Inventor: Tadao Yasuzato
  • Patent number: 7910266
    Abstract: Hole patterns are repeatedly arranged on a mask at a constant pitch in each of predetermined directions. In the predetermined directions, a first direction with the smallest pitch and a second direction with the second smaller pitch are specified. A Levenson phase shifter is formed corresponding to the hole patterns to cause the phases of transmitted light through the hole patterns adjacent to each other in the first direction to be opposite to each other. An exposure process is performed by two-point illumination which is adapted to improve the resolution property in the second direction.
    Type: Grant
    Filed: August 5, 2008
    Date of Patent: March 22, 2011
    Assignee: Elpida Memory, Inc.
    Inventor: Tadao Yasuzato
  • Patent number: 7810066
    Abstract: An irradiation pattern data generation method includes: a process for providing a design pattern having diagonal side portions that extend diagonally with respect to an X-axis direction and a Y-axis direction on an XY plane; a rectangular approximation process for approximating the design pattern to rectangles to generate a rectangular approximation pattern; a first correction process for shifting the side portions of the rectangular approximation pattern in the Y-axis direction to generate a first correction pattern; and a second correction process for enlarging the side portions of the first correction pattern in the X-axis direction and the Y-axis direction to generate an irradiation pattern.
    Type: Grant
    Filed: October 3, 2007
    Date of Patent: October 5, 2010
    Assignee: Elpida Memory, Inc.
    Inventor: Tadao Yasuzato
  • Patent number: 7691543
    Abstract: A method of creating data of a mask for manufacturing a semiconductor device. The mask includes at least one auxiliary pattern arranged adjacent to a line pattern. The at least one auxiliary pattern is allocated in accordance with a rule-based method on the basis of an interval between a first line pattern and a second line pattern adjacent to the first line pattern. Size of the at least one auxiliary pattern is then optimized in accordance with a model-based OPC (Optical Proximity Correction), by shifting edges of the at least one auxiliary pattern and edges for one of the line patterns on the basis of a first light intensity threshold on the at least one auxiliary pattern and a second light intensity threshold on the line patterns.
    Type: Grant
    Filed: May 1, 2006
    Date of Patent: April 6, 2010
    Assignee: Elpida Memory, Inc.
    Inventor: Tadao Yasuzato
  • Patent number: 7681173
    Abstract: In a mask data generation method, when auxiliary patterns are arranged with respect to a device pattern, an arrangement rule for a tip of the device pattern is designed to be different from that for other portions. For portions that are corrected to a large extent by an OPC process, such as the tip of the device pattern, an auxiliary pattern is spaced at an increased distance from the device pattern. Specifically, a distance at which an auxiliary pattern is spaced from the tip of the device pattern is set to be longer than a distance at which an auxiliary pattern is spaced from a long side of the device pattern.
    Type: Grant
    Filed: March 8, 2007
    Date of Patent: March 16, 2010
    Assignee: Elpida Memory, Inc.
    Inventors: Nobue Kosa, Tadao Yasuzato
  • Patent number: 7632614
    Abstract: A circuit pattern exposure method for irradiating illumination light onto a mask to transfer (offset) mask patterns that are formed in the mask to a semiconductor substrate, wherein the mask includes a plurality of main mask patterns that are arranged at a prescribed pitch and auxiliary mask patterns that are arranged outside the outermost main mask pattern and that are not to be transferred (offset) to the semiconductor substrate; the auxiliary mask patterns are provided with a first auxiliary mask row that is arranged adjacent to the outermost main mask pattern and a second auxiliary mask row that is arranged adjacent to the first auxiliary mask row; and the first auxiliary mask row and the second auxiliary mask row are arranged at a pitch that is narrower than the pitch of arrangement of the main mask patterns.
    Type: Grant
    Filed: January 3, 2007
    Date of Patent: December 15, 2009
    Assignee: Elpida Memory, Inc.
    Inventors: Nobue Kosa, Tadao Yasuzato
  • Publication number: 20090202926
    Abstract: An exposure mask is constituted of hole-patterns whose scales are higher than the limit resolution of exposure light and which are repetitively aligned in X-Y directions with the prescribed pitch (ranging from 140 nm to 180 nm) therebetween, halftone phase shift regions whose transmission factors range from 2% to 20% and each of which is aligned between two hole-patterns adjacently lying in the X-direction or the Y-direction so as to apply an inverse phase to incidence light, and light preventive regions each of which is aligned between two hole-patterns adjacently lying in an oblique direction inclined to the X-direction or Y-direction by 45°. The exposure mask is illuminated with azimuthal polarization light which is produced by a secondary light source of a zonal illumination and whose polarization direction is perpendicular to the radial direction of the secondary light source.
    Type: Application
    Filed: February 5, 2009
    Publication date: August 13, 2009
    Applicant: ELPIDA MEMORY, INC.
    Inventor: Tadao YASUZATO
  • Publication number: 20090148780
    Abstract: A method for correcting optical proximity effect of a mask pattern for exposure light, the mask pattern including a rectangular pattern formed by a transparent region having a dimension of limiting resolution of exposure light, includes (a) performing exposure by means of an evaluating mask on which an evaluation pattern including the rectangular pattern is arranged so as to form a pattern on a wafer. Further, the method includes (b) calculating an error between a simulation value obtained by a simulation of exposure, the simulation using the evaluation pattern and a dimension value of the pattern formed on the wafer, and (c) optimizing a simulation parameter so that the error becomes small. The simulation parameter includes at least a first bias value and a second value, the first bias value corrects a corner portion of the rectangular pattern, and the second bias value corrects a side portion of the rectangular pattern.
    Type: Application
    Filed: December 5, 2008
    Publication date: June 11, 2009
    Applicant: ELPIDA MEMORY, INC.
    Inventor: TADAO YASUZATO
  • Publication number: 20090081564
    Abstract: An exposure mask has a rectangular pattern, an auxiliary pattern, a translucent region, and a shielding region. The rectangular pattern includes a transparent region having a dimension equal to or greater than a critical resolution of exposure light. The auxiliary pattern is arranged around the rectangular pattern and includes a transparent region having a dimension smaller than the critical resolution. The translucent region is arranged between the rectangular pattern and the auxiliary pattern for shifting a phase of light transmitted through the rectangular pattern and the auxiliary pattern to an opposite phase. The shielding region is arranged around the auxiliary pattern.
    Type: Application
    Filed: September 18, 2008
    Publication date: March 26, 2009
    Applicant: ELPIDA MEMORY, INC.
    Inventor: Tadao YASUZATO
  • Publication number: 20090042108
    Abstract: Hole patterns are repeatedly arranged on a mask at a constant pitch in each of predetermined directions. In the predetermined directions, a first direction with the smallest pitch and a second direction with the second smaller pitch are specified. A Levenson phase shifter is formed corresponding to the hole patterns to cause the phases of transmitted light through the hole patterns adjacent to each other in the first direction to be opposite to each other. An exposure process is performed by two-point illumination which is adapted to improve the resolution property in the second direction.
    Type: Application
    Filed: August 5, 2008
    Publication date: February 12, 2009
    Applicant: ELPIDA MEMORY, INC.
    Inventor: Tadao Yasuzato
  • Publication number: 20080149859
    Abstract: An irradiation pattern data generation method includes: a process for providing a design pattern having diagonal side portions that extend diagonally with respect to an X-axis direction and a Y-axis direction on an XY plane; a rectangular approximation process for approximating the design pattern to rectangles to generate a rectangular approximation pattern; a first correction process for shifting the side portions of the rectangular approximation pattern in the Y-axis direction to generate a first correction pattern; and a second correction process for enlarging the side portions of the first correction pattern in the X-axis direction and the Y-axis direction to generate an irradiation pattern.
    Type: Application
    Filed: October 3, 2007
    Publication date: June 26, 2008
    Applicant: ELPIDA MEMORY, INC.
    Inventor: Tadao Yasuzato
  • Publication number: 20070212620
    Abstract: In a mask data generation method, when auxiliary patterns are arranged with respect to a device pattern, an arrangement rule for a tip of the device pattern is designed to be different from that for other portions. For portions that are corrected to a large extent by an OPC process, such as the tip of the device pattern, an auxiliary pattern is spaced at an increased distance from the device pattern. Specifically, a distance at which an auxiliary pattern is spaced from the tip of the device pattern is set to be longer than a distance at which an auxiliary pattern is spaced from a long side of the device pattern.
    Type: Application
    Filed: March 8, 2007
    Publication date: September 13, 2007
    Applicant: ELPIDA MEMORY, INC.
    Inventors: Nobue Kosa, Tadao Yasuzato
  • Publication number: 20070160918
    Abstract: A circuit pattern exposure method for irradiating illumination light onto a mask to transfer (offset) mask patterns that are formed in the mask to a semiconductor substrate, wherein the mask includes a plurality of main mask patterns that are arranged at a prescribed pitch and auxiliary mask patterns that are arranged outside the outermost main mask pattern and that are not to be transferred (offset) to the semiconductor substrate; the auxiliary mask patterns are provided with a first auxiliary mask row that is arranged adjacent to the outermost main mask pattern and a second auxiliary mask row that is arranged adjacent to the first auxiliary mask row; and the first auxiliary mask row and the second auxiliary mask row are arranged at a pitch that is narrower than the pitch of arrangement of the main mask patterns.
    Type: Application
    Filed: January 3, 2007
    Publication date: July 12, 2007
    Applicant: ELPIDA MEMORY, INC.
    Inventors: Nobue Kosa, Tadao Yasuzato
  • Publication number: 20060246362
    Abstract: A method of creating data of a mask for manufacturing a semiconductor device. The mask includes at least one auxiliary pattern arranged adjacent to a line pattern. An auxiliary pattern is allocated in accordance with a rule-based method on the basis of an interval between a first line pattern and a second line pattern adjacent to the first line pattern. The size of the auxiliary pattern is then optimized in accordance with a model-based OPC (Optical Proximity Correction).
    Type: Application
    Filed: May 1, 2006
    Publication date: November 2, 2006
    Inventor: Tadao Yasuzato
  • Patent number: 6355382
    Abstract: Disclosed is a photomask in which contrast of light intensity of a pattern to be transferred (main pattern) is enhanced on an image plane while transfer of auxiliary pattern themselves is suppressed.
    Type: Grant
    Filed: December 29, 1999
    Date of Patent: March 12, 2002
    Assignee: NEC Corporation
    Inventors: Tadao Yasuzato, Shinji Ishida