Patents by Inventor Kiichi Sakamoto

Kiichi Sakamoto 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: 5401974
    Abstract: In a charged particle beam exposure apparatus in which a charged particle beam is projected onto a member to be exposed to thereby form a pattern thereon, there are provided a plurality of electrodes disposed around an optical axis of the charged particle beam, a first unit for introducing a gas containing oxygen as a main component into an inside of the charged particle beam exposure apparatus including the plurality of electrodes and for holding the inside of the apparatus at a degree of vacuum between 0.1 Torr and 4 Torr, and a second unit for selectively applying either a high-frequency signal having a frequency between 100 kHz and 800 kHz or a reference signal to each of the plurality of electrodes. A plasma radical state of the gas is generated in the inside of the apparatus so that a deposition present in the apparatus can be eliminated.
    Type: Grant
    Filed: February 3, 1994
    Date of Patent: March 28, 1995
    Assignee: Fujitsu Limited
    Inventors: Yoshihisa Oae, Takamasa Satoh, Yasushi Takahashi, Kiichi Sakamoto, Hiroshi Yasuda, Soichiro Arai, Moritaka Nakamura
  • Patent number: 5393988
    Abstract: A mask is used for exposing a desired pattern on a substrate by a charged particle beam exposure. The mask comprises a plurality of pattern groups each including a plurality of exposure patterns within an approximately rectangular region, and a plurality of position matching patterns formed at positions different from those of the exposure pattern groups, where positional relationships of each of the exposure pattern groups and the position matching patterns are predetermined and fixed.
    Type: Grant
    Filed: April 14, 1994
    Date of Patent: February 28, 1995
    Assignee: Fujitsu Limited
    Inventor: Kiichi Sakamoto
  • Patent number: 5391886
    Abstract: A method of exposing a pattern on a substrate by a charged particle beam includes the steps of energizing first and second mask deflectors provided at an upstream side of a stencil mask simultaneously to obtain a first relativistic relationship of energization between the first and second mask deflectors, energizing the first mask deflector and simultaneously the second mask deflector according to the first relativistic relationship so as to hit a selected aperture on the stencil mask, to obtain an absolute deflection of the charged particle beam as a function of the energization of the first mask deflector, energizing third and fourth mask deflectors provided at a downstream side of the stencil mask simultaneously to obtain a second relativistic relationship of energization between the third and fourth mask deflectors, and energizing the first through fourth mask deflectors according to the first and second relativistic relationship and further to the absolute relationship, such that the charged particle bea
    Type: Grant
    Filed: October 5, 1993
    Date of Patent: February 21, 1995
    Assignee: Fujitsu Limited
    Inventors: Akio Yamada, Yoshihisa Oae, Satoru Yamazaki, Tomohiko Abe, Katsuhiko Kobayashi, Kiichi Sakamoto, Junko Hatta
  • Patent number: 5376802
    Abstract: A stencil mask is used for exposing a pattern on a wafer using a charged particle beam which is transmitted through the stencil mask. The stencil mask is made up of a plate, and at least a block pattern region formed on the plate. The block pattern region includes apertures of arbitrary shapes for transmitting the charged particle beam which irradiates the apertures within the block pattern region in one shot of the charged particle beam. The block pattern region forms a block mask in which a pair of confronting blanking electrodes is provided with respect to at least predetermined ones of the apertures.
    Type: Grant
    Filed: May 18, 1993
    Date of Patent: December 27, 1994
    Assignee: Fujitsu Limited
    Inventors: Kiichi Sakamoto, Yasushi Takahashi, Yoshihisa Oae, Hiroshi Yasuda
  • Patent number: 5364718
    Abstract: A method is provided for exposing a semiconductor device pattern onto a semiconductor substrate by repeatedly exposing an adjoining arrangement of a plurality of unit patterns. The device pattern is first divided into a plurality of unit patterns. Then, a stencil mask is provided with transmitting openings having shapes conforming to the respective unit patterns. Pattern lines on the stencil mask of the unit patterns which are to be connected with each other have at least one connecting end provided with at least one protrusion having a width less than that of the corresponding pattern lines. The protrusion on the connecting end reduces errors such as interruptions or excessive broadening in an exposed pattern line due to misalignment. Also disclosed is a stencil mask for carrying out the present inventive method.
    Type: Grant
    Filed: May 5, 1993
    Date of Patent: November 15, 1994
    Assignee: Fujitsu Limited
    Inventors: Yoshihisa Oae, Kiichi Sakamoto
  • Patent number: 5349197
    Abstract: A method for exposing a pattern of a semiconductor device on an object comprises the steps of extracting block exposure data from design data the semiconductor device, extracting variable exposure data from the design data, extracting fine exposure data from the variable exposure data such that the fine exposure data comprises exposure data for fine elemental patterns that have a size smaller than a predetermined threshold size below which exposure by a variable shaped beam is difficult, extracting mask data indicative of a construction of a beam shaping mask used for shaping the beam based upon the block exposure data, variable exposure data and the fine exposure data, such that the mask data includes information about location, size and shape of apertures formed on the beam shaping mask for shaping the beam, fabricating the beam shaping mask based upon the mask data, and exposing the device pattern by selectively passing the beam through one of the block apertures, the variable exposure aperture and the fin
    Type: Grant
    Filed: September 29, 1992
    Date of Patent: September 20, 1994
    Assignee: Fujitsu Limited
    Inventors: Kiichi Sakamoto, Hiroshi Yasuda
  • Patent number: 5347592
    Abstract: A pattern judging method which is to be implemented on a computer automatically determines whether or not a pattern should be prohibited from being formed in a mask. The pattern judging method includes the steps of (a) dividing an area of the mask where a desired pattern is to be formed into a plurality of regions, (b) calculating a predetermined physical quantity for each of the regions for a case where one or a plurality of openings corresponding to the desired pattern are formed in the mask, and (c) prohibiting the desired pattern from being formed in the mask if the predetermined quantity calculated in the step (b) exceeds a threshold value for at least one of the regions.
    Type: Grant
    Filed: July 23, 1992
    Date of Patent: September 13, 1994
    Assignee: Fujitsu Limited
    Inventors: Hiroshi Yasuda, Satoru Yamazaki, Kiichi Sakamoto
  • Patent number: 5288567
    Abstract: A stencil mask is used for exposing a pattern on a wafer using a charged particle beam which is transmitted through the stencil mask. The stencil mask is made up of a plate, and at least a block pattern region formed on the plate. The block pattern region includes apertures of arbitrary shapes for transmitting the charged particle beam which irradiates the apertures within the block pattern region in one shot of the charged particle beam. The block pattern region forms a block mask in which a pair of confronting blanking electrodes is provided with respect to at least predetermined ones of the apertures.
    Type: Grant
    Filed: June 20, 1991
    Date of Patent: February 22, 1994
    Assignee: Fujitsu Limited
    Inventors: Kiichi Sakamoto, Yasushi Takahashi, Yoshihisa Oae, Hiroshi Yasuda
  • Patent number: 5276334
    Abstract: A charged particle beam exposure method includes the steps of (a) selectively irradiating a charged particle beam on at least one selected opening forming a selected pattern of a mask which includes a plurality of openings related to a plurality of kinds of patterns so as to shape a cross section of the charged particle beam which is transmitted through the selected opening, where the area of the mask is divided into a plurality of blocks each including at least one opening which is related to one pattern, and (b) irradiating the charged particle beam which is transmitted through the selected opening of the mask onto an object surface so as to expose a desired pattern corresponding to at least a part of the pattern of the selected opening on the object surface, where the step (a) carries out first and second deflections independently of each other with respect to the charged particle beam.
    Type: Grant
    Filed: July 22, 1992
    Date of Patent: January 4, 1994
    Assignee: Fujitsu Limited
    Inventors: Akio Yamada, Kiichi Sakamoto, Kenichi Kawashima
  • Patent number: 5276331
    Abstract: An electron beam exposure system having an electromagnetic lens for forming an electron beam into an arbitrary image and for condensing and projecting the image on a sample, and a plurality of saddle type electromagnetic deflectors for deflecting and scanning the electron beam on the sample, wherein at least one of the plurality of saddle type electromagnetic deflectors has a half angle of arc of more than 60 degrees and positions in a vicinity of a smooth connecting line which links four points plotted on a graph having coordinates of the half angle of arc of 60 degrees to no less than a radius of curvature of 30 millimeters, approximately 61.5 degrees to 14 millimeters, approximately 64 degrees to 9 millimeters, and approximately 66 degrees to 7 millimeters. Thus, the electron beam exposure system having the saddle type electromagnetic deflector and which is small and has low aberration is realized.
    Type: Grant
    Filed: October 30, 1992
    Date of Patent: January 4, 1994
    Assignee: Fujitsu Limited
    Inventors: Yoshihisa Oae, Kiichi Sakamoto
  • Patent number: 5262341
    Abstract: A blanking aperture array for use in a charged particle beam exposure has a substrate, at least m rows by n columns of apertures arranged two-dimensionally in the substrate, where each of the apertures have a pair of blanking electrodes and m and n are integers greater than one, and n m-bit shift registers provided on the substrate for applying voltages dependent on pattern data to m pairs of the blanking electrodes of the apertures in the ith column, where i=1, 2, . . . , n. The pattern data is related to a pattern which is to be exposed using the blanking aperture array.
    Type: Grant
    Filed: December 16, 1992
    Date of Patent: November 16, 1993
    Assignee: Fujitsu Limited
    Inventors: Shunsuke Fueki, Hiroshi Yasuda, Kiichi Sakamoto, Yasushi Takahashi
  • Patent number: 5260579
    Abstract: A charged particle beam exposure system is directed to an exposure process of an electron beam for sequentially scanning an electron beam employing a blanking aperture array including a plurality of blanking apertures. The system facilitates re-focusing for compensation of focus error due to Coulumb effect and makes wiring the blanking aperture array easier. The system further allows exposure without an irradiation gap. The blanking aperture array 6 is formed with a plurality of said blanking apertures 62 arranged in a two-dimensional configuration. A control system 24 controls the blanking aperture array 62 to set the blanking aperture to the ON state where the charged particle beams pass through the blanking aperture and reach the object 19 to be exposed or the OFF state where the charged particle beams cannot reach the object 19 to be exposed.
    Type: Grant
    Filed: March 13, 1992
    Date of Patent: November 9, 1993
    Assignee: Fujitsu Limited
    Inventors: Hiroshi Yasuda, Yasushi Takahashi, Kiichi Sakamoto, Akio Yamada, Yoshihisa Oae, Junichi Kai, Shunsuke Fueki, Kenichi Kawashima
  • Patent number: 5256881
    Abstract: A transmission mask is used when exposing patterns by a charged particle beam which passes therethrough. The transmission mask includes a plate, and a plurality of rectangular blocks formed on a surface of the plate and having an area approximately equal to a cross sectional area of the charged particle beam irradiated thereon, where the blocks include a first block in which at least one transmission hole is provided and a second block in which no transmission hole is provided. The transmission of the first block is partly irradiated by the charged particle beam when varying the size of the exposing pattern. A single second block is provided immediately adjacent to at least two first blocks, so that an irradiating position of the charged particle beam can be varied with respect to both the two first blocks from the single second block.
    Type: Grant
    Filed: June 10, 1992
    Date of Patent: October 26, 1993
    Assignee: Fujitsu Limited
    Inventors: Satoru Yamazaki, Hiroshi Yasuda, Kiichi Sakamoto
  • Patent number: 5234781
    Abstract: A mask for lithographic patterning comprises a base body provided with a through hole passing from a top side to a bottom side thereof, a mask layer provided on the top side of the base body so as to close the through hole, the mask layer being defined by a substantially flat top surface and a substantially flat bottom surface and having a thickness ranging from about 2 .mu.m to about 20 .mu.m, and a plurality of patterned apertures provided on the mask layer at a part closing the through hole.
    Type: Grant
    Filed: April 30, 1992
    Date of Patent: August 10, 1993
    Assignee: Fujitsu Limited
    Inventors: Kiichi Sakamoto, Hiroshi Yasuda
  • Patent number: 5225684
    Abstract: A charged particle beam exposure system emits and deflects an electron beam (11a) toward a continuously moving exposure object (18) and draws semiconductor integrated circuit patterns on the object. The system comprises a charged particle beam generating unit (11), first and second deflectors (12 and 13) for deflecting the electron beam (11a), first and second deflector drivers (14 and 15) for controlling outputs of the first and second deflectors (12 and 13), a stage driving and controlling unit (16) for controlling the movement of the object (18), and a controller (17) for controlling the inputs and outputs of the respective components.
    Type: Grant
    Filed: September 22, 1992
    Date of Patent: July 6, 1993
    Assignee: Fujitsu Limited
    Inventors: Kazutaka Taki, Hiroshi Yasuda, Junichi Kai, Atsushi Saito, Kiichi Sakamoto
  • Patent number: 5223719
    Abstract: A charged particle beam mask and apparatus and method of using the same employing a mask that includes a substrate and a plurality of substantially rectangular beam passing sections arranged in parallel and to have a trapezoidal shape. In addition, the masks having a matrix of irradiation areas formed thereon where each irradiation area has a matrix of block patterns, are aligned and selectively irradiated to form a desired pattern on an object.
    Type: Grant
    Filed: July 5, 1991
    Date of Patent: June 29, 1993
    Assignee: Fujitsu Limited
    Inventors: Yasushi Takahashi, Kiichi Sakamoto, Yoshihisa Oae, Hiroshi Yasuda, Nobuyuki Yasutake
  • Patent number: 5194741
    Abstract: A method for writing a pattern on a surface of an object by a focused electron beam with a minimized distortion of the electron beam comprises the steps of dividing the surface of the object into a plurality of parallel bands, moving the object in a direction perpendicular to the bands with a predetermined speed, achieving an exposure of the device pattern on an individual, band by band basis while moving the object with the predetermined speed. The predetermine speed is optimized with respect to an exposure interval representing a time interval in which the exposure of the band is possible.
    Type: Grant
    Filed: March 20, 1992
    Date of Patent: March 16, 1993
    Assignee: Fujitsu Limited
    Inventors: Kiichi Sakamoto, Yoshihisa Oae, Junko Hatta, Yasushi Takahashi
  • Patent number: 5180919
    Abstract: An electron beam exposure system having a capability of checking a pattern to be written on an object comprises an electron beam source for producing an electron beam along an optical axis toward the object, a block mask provided on the optical axis and having selectable aperture patterns therein for correspondingly shaping the electron beam, an addressing deflector fixture for selectively passing the electron beam through a desired aperture on the block mask, an electron optical system for focusing the electron beam shaped by the block mask on the object such that an image of the aperture of the block mask is projected on the object, a screen provided along the optical axis between the block mask and the object for interrupting the electron beam when the electron beam is offset from the alignment with the optical axis, the screen having a through-hole in alignment with the optical axis for passing the electron beam therethrough a controller for controlling the electron optical system such that an image of th
    Type: Grant
    Filed: September 18, 1991
    Date of Patent: January 19, 1993
    Assignee: Fujitsu Limited
    Inventors: Yoshihisa Oae, Kiichi Sakamoto, Hiroshi Yasuda
  • Patent number: 5175435
    Abstract: An electron beam exposure system comprises a pattern data generator for producing first pattern data indicative of a desired pattern of electron beam to be written on a wafer and second pattern data indicative of the number of repetitions of the pattern specified by the first pattern data, as a time sequential mixture of the first and second pattern data. The time sequential mixture of the data is sorted in a data sorting unit into a parallel data of the first pattern data and the second pattern data. Then, a discrimination is made whether the data is the first pattern data or the second pattern data, and when the data is the second pattern data, the data that follows immediately behind the second pattern data is transferred to an output path simultaneously with the second pattern data, which is transferred to another output path. Thereby, the first and second pattern data form a parallel data.
    Type: Grant
    Filed: October 25, 1991
    Date of Patent: December 29, 1992
    Assignee: Fujitsu Limited
    Inventors: Kiichi Sakamoto, Shunsuke Fueki, Hiroshi Yasuda
  • Patent number: 5173582
    Abstract: A charged particle beam lithography system includes a beam source of a charged particle beam, a beam shaping aperture for providing a predetermined cross section to the charged particle beam, a first focusing system for focusing the charged particle beam on a first crossover point located on the optical axis, a second focusing system provided between the first crossover point and an object for focusing the charged particle beam on a second crossover point located on the optical axis, a beam deflection system for deflecting the electron beam such that the beam is displaced on the surface of the object, a stage for supporting the object, a mask provided in a vicinity of said first focusing system, and an addressing system for selectively deflecting the charged particle beam such that the charged particle beam is passed through a selected aperture on the mask.
    Type: Grant
    Filed: September 20, 1990
    Date of Patent: December 22, 1992
    Assignee: Fujitsu Limited
    Inventors: Kiichi Sakamoto, Hiroshi Yasuda, Akio Yamada