Patents by Inventor Shoji Mimotogi

Shoji Mimotogi 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: 20090244512
    Abstract: A lithography process window analyzing method for setting a process window based on ranges of exposure amounts and focus positions, and giving evaluation of reliability of the set process window, includes setting, based on a plurality of process conditions including exposure amounts and focus positions in the performed exposure processing, analysis reliability M for process conditions including an arbitrary exposure amount and an arbitrary focus position; calculating reliability R of the process window based on the analysis reliability M concerning the process conditions included in the process window; and comparing a magnitude relation between the reliability R and a predetermined threshold and determining presence or absence of reliability of the process window according to a result of the comparison.
    Type: Application
    Filed: March 9, 2009
    Publication date: October 1, 2009
    Inventors: Shoji Mimotogi, Yasuharu Sato
  • Publication number: 20090244504
    Abstract: A projection exposure method that projects the shape of a hole onto a wafer by projecting a diffracted light, which is produced by applying light to a mask having a pattern for forming a hole pattern, onto the wafer through a projection optical system for exposure, wherein, in a plane substantially perpendicular to an optical axis, the light applied to the mask has a first intensity distribution in which the intensity is higher in the vicinity of eight apexes of an octagon centered at the optical axis than in other areas, the mask has a plurality of first opening patterns are arranged in a rectangular lattice configuration having sides parallel to diagonals of the octagon passing through the optical axis, and a plurality of second opening patterns are arranged in a face-centered rectangular lattice configuration having sides parallel to diagonals of the octagon passing through the optical axis.
    Type: Application
    Filed: February 27, 2009
    Publication date: October 1, 2009
    Inventors: Yosuke Kitamura, Masaki Satake, Shoji Mimotogi, Kazuya Fukuhara
  • Patent number: 7596776
    Abstract: A light intensity distribution simulation method for predicting an intensity distribution of light on a substrate when photomask including a pattern is irradiated with light in which a shape distribution of an effective light source is defined includes extracting plural point light sources from a shape distribution of the effective light source, entering the light emitted from each of the plural point light sources onto the pattern of the photomask, calculating an effective shape for each of the plural point light sources, the effective shape being a pattern obtained by excluding a part which is not irradiated with the light directly due to a sidewall of a pattern film including the pattern from a design shape of an aperture of the pattern, and calculating a distribution of diffraction light generated in the pattern for each of the plural point light sources by using the effective shape.
    Type: Grant
    Filed: March 29, 2007
    Date of Patent: September 29, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Satoshi Tanaka, Shoji Mimotogi, Takashi Sato, Soichi Inoue
  • Publication number: 20090240362
    Abstract: A simulation model creating method computes, for measurement results of a line width of a resist pattern formed with varied an exposure amount and focus value, a permissible fluctuation range of the pattern line width from a distribution of the exposure amount and a distribution of the focus value; computes difference values between the measurement results and corresponding approximation values on a fitting function which has the exposure amount and focus value as parameters; compares the difference values with the permissible fluctuation range; deletes any measurement values for which the difference value is larger than the permissible fluctuation range, and recomputes the fitting function accordingly; and deletes measurement values outside a permissible fluctuation range of a pattern line width of the mask, and creates a simulation model.
    Type: Application
    Filed: March 18, 2009
    Publication date: September 24, 2009
    Inventors: Shoji Mimotogi, Masafumi Asano
  • Publication number: 20090217233
    Abstract: A method of simulating an optical intensity distribution on a substrate when a mask pattern formed on the mask is transferred to the substrate through a projection optical system by irradiating an illumination light obliquely on a mask surface of the mask, which comprises setting a phase difference between a zero-order diffraction light and a first-order diffraction light determined according to at least one of a distance between the zero-order diffraction light and the first-order diffraction light on a pupil of the projection optical system, thickness of a light-shielding portion formed on the mask, angle defined by an optical axis direction of the illumination light and an incident direction on the mask, and a difference between a size of the mask pattern and a half cycle of the mask pattern, and carrying out a simulation of the optical intensity distribution on the substrate according to the set phase difference.
    Type: Application
    Filed: February 27, 2009
    Publication date: August 27, 2009
    Inventors: Akiko Mimotogi, Satoshi Tanaka, Shoji Mimotogi, Takashi Sato
  • Patent number: 7575835
    Abstract: An exposure method is disclosed, which comprises preparing a first mask in which a size of a mask pattern is measured in advance, calculating a first exposure quantity to be applied to the first mask to provide a first resist pattern by using the first mask, simulating optical intensity distributions on a wafer in a case where the first mask is used and an optical intensity distribution on the wafer in a case where a second mask is used, a size of a mask pattern of the second mask being measured in advance, calculating a difference in optical intensity between the first mask and the second mask from the simulated optical intensity distributions, and calculating a second exposure quantity to be applied to the second mask to provide a second resist pattern, from the first exposure quantity and the difference in optical intensity.
    Type: Grant
    Filed: August 30, 2006
    Date of Patent: August 18, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takashi Sato, Shoji Mimotogi, Shigeru Hasebe
  • Publication number: 20090202924
    Abstract: A method of evaluating a photo mask, includes measuring each dimension of a plurality of pattern portions of a mask pattern formed on a photo mask, obtaining an inter-pattern distance between the pattern portion and a pattern different from the pattern portion with respect to each of the pattern portions, obtaining a dimensional difference between the measured dimension of the pattern portion and a target dimension of the pattern portion with respect to each of the pattern portions, grouping the dimensional difference obtained for each pattern portion into a plurality of groups in accordance with the inter-pattern distance obtained for each pattern portion, obtaining an evaluation value based on the dimensional difference in each group with respect to each of the groups, and evaluating the photo mask based on the evaluation value.
    Type: Application
    Filed: January 28, 2009
    Publication date: August 13, 2009
    Inventors: Hiroki YAMAMOTO, Masamitsu Itoh, Osamu Ikenaga, Shoji Mimotogi, Hideki Kanai, Yukiyasu Arisawa
  • Patent number: 7560197
    Abstract: A mask pattern data producing method is disclosed, which comprises preparing design pattern data in which contact holes are arranged on part of the grid points in matrix, preparing first mask pattern data in which first opening patterns are arranged on all of the grid points, and designing second mask pattern data in which second opening patterns and third opening patterns are arranged, the second opening patterns being arranged on the grid points at which the contact holes are arranged in the design pattern data to include the first opening patterns, the third opening patterns being arranged on a pair of grid points, which is a pair of diagonal grid points only on which the contact holes are arranged in a unit grid formed by four grid points, to include the first opening patterns arranged on the pair of grid points, in place of the second opening patterns.
    Type: Grant
    Filed: February 22, 2005
    Date of Patent: July 14, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroko Nakamura, Toshiya Kotani, Satoshi Tanaka, Shoji Mimotogi
  • Publication number: 20090019418
    Abstract: A lithography simulation method includes: taking in design data of a pattern to be formed on a substrate and mask data to prepare a mask pattern used in forming a latent image of the pattern on the substrate by transmission of an energy ray; obtaining the latent image of the pattern by calculation of an intensity of the energy ray; locally changing, at least in a portion corresponding to a pattern to be interested, a relative position in a direction of the intensity of the energy ray between a latent image curve and a reference intensity line in accordance with a distance between the pattern to be interested and a pattern of a neighboring region, the latent image curve being an intensity distribution curve of the energy ray constituting the latent image, the reference intensity line being defined to specify a position of an edge of the pattern to be interested; and calculating a distance between intersections of a portion of the latent image curve corresponding to the pattern to be interested and the referenc
    Type: Application
    Filed: August 11, 2008
    Publication date: January 15, 2009
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Toshiya Kotani, Shigeki Nojima, Shoji Mimotogi
  • Patent number: 7446852
    Abstract: A projection exposure mask acceptance decision system includes assurance object measuring unit to measure quality assurance objects relating to projection exposure mask, first exposure characteristic deterioration quantity calculating unit to calculate first exposure characteristic deterioration quantity caused by deviations in average values of the quality assurance objects measured by the measuring unit, second exposure characteristic deterioration quantity calculating unit to calculate second exposure characteristic deterioration quantity caused by dispersion in the quality assurance objects measured by the measuring unit, sum calculating unit to calculate simple sum of the first and second quantity, root sum square calculating unit to calculate root sum square of the first and second quantity, entire exposure characteristic deterioration quantity calculating unit to calculate entire exposure characteristic deterioration quantity as an interior division value of the simple sum and root sum square, and judg
    Type: Grant
    Filed: January 16, 2007
    Date of Patent: November 4, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yukiyasu Arisawa, Shoji Mimotogi, Shigeru Hasebe
  • Patent number: 7426712
    Abstract: A lithography simulation method includes: taking in design data of a pattern to be formed on a substrate and mask data to prepare a mask pattern used in forming a latent image of the pattern on the substrate by transmission of an energy ray; obtaining the latent image of the pattern by calculation of an intensity of the energy ray; locally changing, at least in a portion corresponding to a pattern of interest, a relative position in a direction of the intensity of the energy ray between a latent image curve and a reference intensity line in accordance with a distance between the pattern of interest and a pattern of a neighboring region , the latent image curve being an intensity distribution curve of the energy ray constituting the latent image, the reference intensity line being defined to specify a position of an edge of the pattern of interest; and calculating a distance between intersections of a portion of the latent image curve corresponding to the pattern of interest and the reference intensity line in
    Type: Grant
    Filed: July 13, 2006
    Date of Patent: September 16, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshiya Kotani, Shigeki Nojima, Shoji Mimotogi
  • Patent number: 7336341
    Abstract: A simulator of a lithography tool includes a correcting parameter memory storing a correcting scaling value to correct a focus error of a projection optical system in the lithography tool and a correcting bias to correct a critical dimension error generated in the lithography tool. A model simulation engine simulates an image formation under a corrected focus calculated by multiplying a defocus of the projection optical system by the correcting scaling value to model a calculated critical dimension of an image. A bias corrector adds the correcting bias to the calculated critical dimension to correct the image.
    Type: Grant
    Filed: January 31, 2005
    Date of Patent: February 26, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shoji Mimotogi, Daisuke Kawamura, Akiko Yamada
  • Patent number: 7319944
    Abstract: A computer implemented method for development profile simulation in accordance with an embodiment of the present invention includes calculating optical intensities in a photosensitive resist, calculating a spatial average value of the optical intensities, reading a measured changing ratio of a dissolution rate of the photosensitive resist relating to an alkaline concentration changed by at least one of exposure dose on the photosensitive resist, a position in the thickness direction of the photosensitive resist and an alkaline concentration of developer for the photosensitive resist, obtaining a calculated dissolution rate by using the spatial average value and the measured changing ratio, and predicting a pattern shape of the photosensitive resist from the calculated dissolution rate.
    Type: Grant
    Filed: January 21, 2004
    Date of Patent: January 15, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroko Nakamura, Shoji Mimotogi, Yasunobu Onishi
  • Publication number: 20080004852
    Abstract: A method of creating a simulation model, includes acquiring a CD value of a photoresist pattern actually formed based upon a test pattern, acquiring information about a shape of the photoresist pattern, acquiring an intensity distribution of an optical image based upon the test pattern by performing simulation, acquiring an empirical threshold defined according to a CD value on the intensity distribution, which corresponds to the CD value of the photoresist pattern, acquiring a parameter of the optical image based upon the intensity distribution of the optical image, acquiring a first correlation between the information about the shape of the photoresist pattern and the parameter of the optical image, acquiring a second correlation between the information about the shape of the photoresist pattern and the empirical threshold, and acquiring a third correlation between the parameter of the optical image and the empirical threshold by using first and second correlations.
    Type: Application
    Filed: May 30, 2007
    Publication date: January 3, 2008
    Inventors: Masaki Satake, Shoji Mimotogi
  • Publication number: 20070234269
    Abstract: A light intensity distribution simulation method for predicting an intensity distribution of light on a substrate when photomask including a pattern is irradiated with light in which a shape distribution of an effective light source is defined includes extracting plural point light sources from a shape distribution of the effective light source, entering the light emitted from each of the plural point light sources onto the pattern of the photomask, calculating an effective shape for each of the plural point light sources, the effective shape being a pattern obtained by excluding a part which is not irradiated with the light directly due to a sidewall of a pattern film including the pattern from a design shape of an aperture of the pattern, and calculating a distribution of diffraction light generated in the pattern for each of the plural point light sources by using the effective shape.
    Type: Application
    Filed: March 29, 2007
    Publication date: October 4, 2007
    Inventors: Satoshi Tanaka, Shoji Mimotogi, Takashi Sato, Soichi Inoue
  • Publication number: 20070182941
    Abstract: A projection exposure mask acceptance decision system includes assurance object measuring unit to measure quality assurance objects relating to projection exposure mask, first exposure characteristic deterioration quantity calculating unit to calculate first exposure characteristic deterioration quantity caused by deviations in average values of the quality assurance objects measured by the measuring unit, second exposure characteristic deterioration quantity calculating unit to calculate second exposure characteristic deterioration quantity caused by dispersion in the quality assurance objects measured by the measuring unit, sum calculating unit to calculate simple sum of the first and second quantity, root sum square calculating unit to calculate root sum square of the first and second quantity, entire exposure characteristic deterioration quantity calculating unit to calculate entire exposure characteristic deterioration quantity as an interior division value of the simple sum and root sum square, and judg
    Type: Application
    Filed: January 16, 2007
    Publication date: August 9, 2007
    Inventors: Yukiyasu Arisawa, Shoji Mimotogi, Shigeru Hasebe
  • Patent number: 7248349
    Abstract: There is disclosed an exposure method for correcting a focal point, comprising: illuminating a mask, in which a mask-pattern including at least a set of a first mask-pattern and a second mask-pattern mutually different in shape is formed, from a direction in which a point located off an optical axis of an exposure apparatus is a center of illumination, and exposing and projecting an image of said mask-pattern toward an image-receiving element; measuring a mutual relative distance between images of said first and second mask-patterns exposed and projected on said image-receiving element, thereby measuring a focal point of a projecting optical system of said exposure apparatus; and moving said image-receiving element along a direction of said optical axis of said exposure apparatus on a basis of a result of said measurement, and disposing said image-receiving element at an appropriate focal point of said projecting optical system.
    Type: Grant
    Filed: September 8, 2005
    Date of Patent: July 24, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takashi Sato, Shoji Mimotogi, Takahiro Ikeda, Soichi Inoue
  • Patent number: 7229721
    Abstract: A method for evaluating a photo mask comprises preparing a photo mask including a unit drawing pattern, finding a dimensional variation relating to the photo mask, the dimensional variation including first and second dimensional variations, the first dimensional variation occurring due to a positional displacement and size mismatch of the unit drawing pattern in the photo mask and the second dimensional variation occurring due to etching and development relating to a manufacturing of the photo mask, estimating a deteriorated amount of an exposure latitude occurring due to the dimensional variation of the photo mask using the dimensional variation and a degree of influence of the dimensional variation for the exposure latitude, and judging quality of the photo mask by comparing the deteriorated amount of the exposure latitude and an allowable deteriorated amount of the exposure latitude.
    Type: Grant
    Filed: November 13, 2003
    Date of Patent: June 12, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shoji Mimotogi, Shigeki Nojima, Osamu Ikenaga
  • Publication number: 20070019058
    Abstract: A lithography simulation method includes: taking in design data of a pattern to be formed on a substrate and mask data to prepare a mask pattern used in forming a latent image of the pattern on the substrate by transmission of an energy ray; obtaining the latent image of the pattern by calculation of an intensity of the energy ray; locally changing, at least in a portion corresponding to a pattern to be interested, a relative position in a direction of the intensity of the energy ray between a latent image curve and a reference intensity line in accordance with a distance between the pattern to be interested and a pattern of a neighboring region, the latent image curve being an intensity distribution curve of the energy ray constituting the latent image, the reference intensity line being defined to specify a position of an edge of the pattern to be interested; and calculating a distance between intersections of a portion of the latent image curve corresponding to the pattern to be interested and the referenc
    Type: Application
    Filed: July 13, 2006
    Publication date: January 25, 2007
    Inventors: Toshiya Kotani, Shigeki Nojima, Shoji Mimotogi
  • Publication number: 20070005280
    Abstract: A photomask quality estimation system comprises a measuring unit, a latitude computation unit and an estimation unit. The measuring unit measures the mask characteristic of each of a plurality of chip patterns formed on a mask substrate. The latitude computation unit computes the exposure latitude of each chip pattern based on the mask characteristic. The estimation unit estimates the quality of each chip pattern based on the exposure latitude.
    Type: Application
    Filed: June 27, 2006
    Publication date: January 4, 2007
    Inventors: Yukiyasu Arisawa, Tadahito Fujisawa, Shoji Mimotogi