Patents by Inventor Yoshihisa Ooaeh
Yoshihisa Ooaeh 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: 6420700Abstract: A method of exposing a wafer to a charged-particle beam by directing to the wafer the charged-particle beam deflected by a deflector includes the steps of arranging a plurality of first marks at different heights, focusing the charged-particle beam on each of the first marks by using a focus coil provided above the deflector, obtaining a focus distance for each of the first marks, obtaining deflection-efficiency-correction coefficients for each of the first marks, and using linear functions of the focus distance for approximating the deflection-efficiency-correction coefficients to obtain the deflection-efficiency-correction coefficients for an arbitrary value of the focus distance. A device for carrying out the method is also set forth.Type: GrantFiled: April 6, 2001Date of Patent: July 16, 2002Assignee: Fujitsu LimitedInventors: Yoshihisa Ooaeh, Kenichi Kawakami
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Publication number: 20010013581Abstract: A method of exposing a wafer to a charged-particle beam by directing to the wafer the charged-particle beam deflected by a deflector includes the steps of arranging a plurality of first marks at different heights, focusing the charged-particle beam on each of the first marks by using a focus coil provided above the deflector, obtaining a focus distance for each of the first marks, obtaining deflection-efficiency-correction coefficients for each of the first marks, and using linear functions of the focus distance for approximating the deflection-efficiency-correction coefficients to obtain the deflection-efficiency-correction coefficients for an arbitrary value of the focus distance. A device for carrying out the method is also set forth.Type: ApplicationFiled: April 6, 2001Publication date: August 16, 2001Inventors: Akio Takemoto, Yoshihisa Ooaeh, Tomohiko Abe, Hiroshi Yasuda, Takamasa Satoh, Hideki Nasuno, Hidefumi Yabara, Kenichi Kawakami, Kiichi Sakamoto, Tomohiro Sakazaki, Isamu Seto, Masami Takigawa, Tatsuro Ohkawa
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Patent number: 6242751Abstract: A method of exposing a wafer to a charged-particle beam by directing to the wafer the charged-particle beam deflected by a deflector includes the steps of arranging a plurality of first marks at different heights, focusing the charged-particle beam on each of the first marks by using a focus coil provided above the deflector, obtaining a focus distance for each of the first marks, obtaining deflection-efficiency-correction coefficients for each of the first marks, and using linear functions of the focus distance for approximating the deflection-efficiency-correction coefficients to obtain the deflection-efficiency-correction coefficients for an arbitrary value of the focus distance. A device for carrying out the method is also set forth.Type: GrantFiled: July 15, 1999Date of Patent: June 5, 2001Assignee: Fujitsu LimitedInventors: Akio Takemoto, Yoshihisa Ooaeh, Tomohiko Abe, Hiroshi Yasuda, Takamasa Satoh, Hideki Nasuno, Hidefumi Yabara, Kenichi Kawakami, Kiichi Sakamoto, Tomohiro Sakazaki, Isamu Seto, Masami Takigawa, Tatsuro Ohkawa
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Patent number: 6057907Abstract: Before figure data are expanded into a bitmap, a checksum is calculated in unit of bitmap data corresponding to a cell stripe of scanning over which continuous exposure is possible. When the checksum is calculated after expanding the data into the bitmap, the interim calculation result of refocus values is used. In exposure, exposing k number of sub rectangular areas by repeating a sub scanning k number of times, jumping a deflection by a main deflector toward an center of remaining sub rectangular areas whose number is (p-k) inside a main rectangular areas and exposing remained (p-k) number of the sub rectangular areas by repeating the sub scanning (p-k) times after the jumping is settled. In an amplifier & low pass filter for supplying a drive voltage to a sub deflector, the cutoff frequency is lowed during flyback in a sawtooth waveform without changing an amplification factor.Type: GrantFiled: August 12, 1998Date of Patent: May 2, 2000Assignee: Fujitsu LimitedInventors: Takamasa Satoh, Soichiro Arai, Kenichi Miyazawa, Yoshihisa Ooaeh, Junichi Kai, Hiroshi Yasuda
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Patent number: 6055719Abstract: The present invention relates to a charged particle beam exposure apparatus, deflecting a charged particle beam formed into a predetermined shape by being passed through a predetermined transmission mask, and irradiating a predetermined location on the surface of a sample with the charged particle beam. The apparatus comprises: a mirror barrel through which the charged particle beam is passed; and an electrostatic deflector, provided in the mirror barrel, for deflecting the charged particle beam. The electrostatic deflector has a plurality of pairs of electrodes, which are made of a conductive material having carbon as a primary element and are embedded in an internal face of an insulating cylinder. The present invention also relates to a method for forming the electrostatic deflector.Type: GrantFiled: March 5, 1998Date of Patent: May 2, 2000Assignee: Fujitsu LimitedInventors: Yoshihisa Ooaeh, Tomohiko Abe, Hiroshi Yasuda
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Patent number: 5981960Abstract: A charged particle beam exposure method and apparatus, in which a charged particle beam is shaped based on pattern data and the shaped charged particle beam is irradiated to a desired location on a sample. The method and apparatus includes introducing ozone gas into a chamber through which the charged particle beam is passed, shaped and deflected, to be irradiated to the desired location while the charged particle beam is irradiated through the chamber. The ozone gas concentration in the chamber is maintained so that the concentration downstream along the beam is higher than the concentration upstream along the beam. A charge-up drift due to a contamination material from a resist on a wafer can be avoided by the ozone self cleaning. The ozone oxidation does not occur at the upstream chamber where there is a lower ozone concentration and lower contamination.Type: GrantFiled: October 2, 1996Date of Patent: November 9, 1999Assignee: Fujitsu LimitedInventors: Yoshihisa Ooaeh, Akio Yamada, Hiroshi Yasuda, Hitoshi Tanaka
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Patent number: 5969365Abstract: A method of exposing a wafer to a charged-particle beam by directing to the wafer the charged-particle beam deflected by a deflector includes the steps of arranging a plurality of first marks at different heights, focusing the charged-particle beam on each of the first marks by using a focus coil provided above the deflector, obtaining a focus distance for each of the first marks, obtaining deflection-efficiency-correction coefficients for each of the first marks, and using linear functions of the focus distance for approximating the deflection-efficiency-correction coefficients to obtain the deflection-efficiency-correction coefficients for an arbitrary value of the focus distance. A device for carrying out the method is also set forth.Type: GrantFiled: August 26, 1997Date of Patent: October 19, 1999Assignee: Fujitsu LimitedInventors: Akio Takemoto, Yoshihisa Ooaeh, Tomohiko Abe, Hiroshi Yasuda, Takamasa Satoh, Hideki Nasuno, Hidefumi Yabara, Kenichi Kawakami, Kiichi Sakamoto, Tomohiro Sakazaki, Isamu Seto, Masami Takigawa, Tatsuro Ohkawa
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Patent number: 5949078Abstract: An electron gun for emitting an electron beam traveling along a beam axis includes a cathode having a tip, the tip having substantially a circular conic shape and a tip surface substantially at the beam axis, the cathode being applied with a first voltage, an anode having a first aperture substantially on the beam axis and being applied with a second voltage higher than the first voltage, a control electrode having a second aperture substantially on the beam axis and being applied with a voltage lower that the first voltage to control a current of the cathode, the second aperture being larger than the tip surface, a guide electrode having a third aperture substantially on the beam axis, being arranged between the cathode and the anode, and being applied with a voltage higher than the first voltage and lower than the second voltage, the third aperture being smaller than the tip surface, and a lens electrode having a fourth aperture substantially on the beam axis, being arranged between the guide electrode andType: GrantFiled: August 7, 1998Date of Patent: September 7, 1999Assignee: Fujitsu LimitedInventors: Yoshihisa Ooaeh, Tomohiko Abe, Akio Yamada, Hiroshi Yasuda, Kenj Kudoh, Kouzi Takahata
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Patent number: 5872366Abstract: An electron gun for emitting an electron beam traveling along a beam axis includes a cathode having a tip, the tip having substantially a circular conic shape and a tip surface substantially at the beam axis, the cathode being applied with a first voltage, an anode having a first aperture substantially on the beam axis and being applied with a second voltage higher than the first voltage, a control electrode having a second aperture substantially on the beam axis and being applied with a voltage lower than the first voltage to control a current of the cathode, the second aperture being larger than the tip surface, a guide electrode having a third aperture substantially on the beam axis, being arranged between the cathode and the anode, and being applied with a voltage higher than the first voltage and lower than the second voltage, the third aperture being smaller than the tip surface, and a lens electrode having a fourth aperture substantially on the beam axis, being arranged between the guide electrode andType: GrantFiled: August 8, 1997Date of Patent: February 16, 1999Assignee: Fujitsu LimitedInventors: Yoshihisa Ooaeh, Tomohiko Abe, Akio Yamada, Hiroshi Yasuda, Kenj Kudoh, Kouzi Takahata
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Patent number: 5866300Abstract: Before figure data are expanded into a bitmap, a checksum is calculated in unit of bitmap data corresponding to a cell stripe of scanning over which continuous exposure is possible. When the checksum is calculated after expanding the data into the bitmap, the interim calculation result of refocus values is used. In exposure, exposing k number of sub rectangular areas by repeating a sub scanning k number of times, jumping a deflection by a main deflector toward an center of remaining sub rectangular areas whose number is (p-k) inside a main rectangular areas and exposing remained (p-k) number of the sub rectangular areas by repeating the sub scanning (p-k) times after the jumping is settled. In an amplifier & low pass filter for supplying a drive voltage to a sub deflector, the cutoff frequency is lowed during flyback in a sawtooth waveform without changing an amplification factor.Type: GrantFiled: May 22, 1996Date of Patent: February 2, 1999Assignee: Fujitsu LimitedInventors: Takamasa Satoh, Soichiro Arai, Kenichi Miyazawa, Yoshihisa Ooaeh, Junichi Kai, Hiroshi Yasuda
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Patent number: 5854490Abstract: An electron gun for emitting an electron beam traveling along a beam axis includes a cathode having a tip, the tip having substantially a circular conic shape and a tip surface substantially at the beam axis, the cathode being applied with a first voltage, an anode having a first aperture substantially on the beam axis and being applied with a second voltage higher than the first voltage, a control electrode having a second aperture substantially on the beam axis and being applied with a voltage lower than the first voltage to control a current of the cathode, the second aperture being larger than the tip surface, a guide electrode having a third aperture substantially on the beam axis, being arranged between the cathode and the anode, and being applied with a voltage higher than the first voltage and lower than the second voltage, the third aperture being smaller than the tip surface, and a lens electrode having a fourth aperture substantially on the beam axis, being arranged between the guide electrode andType: GrantFiled: July 16, 1996Date of Patent: December 29, 1998Assignee: Fujitsu LimitedInventors: Yoshihisa Ooaeh, Akio Yamada, Hiroshi Yasuda
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Patent number: 5814423Abstract: A transmission mask for a charged particle beam exposure apparatus that includes a mask substrate having a plurality of apertures arrange in a matrix and a pair of deflection electrodes at each aperture on one surface of the mask substrate. A beam shield layer having a reflectivity to the charged particle beam greater than the mask substrate is positioned on the other surface of the mask substrate. The transmission mask is installed in the apparatus so that the beam shield layer is oriented towards the charged particle beam to prevent an increase in temperature due to irradiation of the charged particle beam.Type: GrantFiled: October 30, 1996Date of Patent: September 29, 1998Assignee: Fujitsu LimitedInventors: Shigeru Maruyama, Hiroshi Yasuda, Yoshihisa Ooaeh
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Patent number: 5770862Abstract: The present invention relates to a charged particle beam exposure apparatus, deflecting a charged particle beam formed into a predetermined shape by being passed through a predetermined transmission mask, and irradiating a predetermined location on the surface of a sample with the charged particle beam. The apparatus comprises: a mirror barrel through which the charged particle beam is passed; and an electrostatic deflector, provided in the mirror barrel, for deflecting the charged particle beam. The electrostatic deflector has a plurality of pairs of electrodes, which are made of a conductive material having carbon as a primary element and are embedded in an internal face of an insulating cylinder. The present invention also relates to a method for forming the electrostatic deflector.Type: GrantFiled: December 4, 1996Date of Patent: June 23, 1998Assignee: Fujitsu Ltd.Inventors: Yoshihisa Ooaeh, Tomohiko Abe, Hiroshi Yasuda
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Patent number: 5757015Abstract: A method of exposing a wafer to a charged-particle beam by directing to the wafer the charged-particle beam deflected by a deflector includes the steps of arranging a plurality of first marks at different heights, focusing the charged-particle beam on each of the first marks by using a focus coil provided above the deflector, obtaining a focus distance for each of the first marks, obtaining deflection-efficiency-correction coefficients for each of the first marks, and using linear functions of the focus distance for approximating the deflection-efficiency-correction coefficients to obtain the deflection-efficiency-correction coefficients for an arbitrary value of the focus distance. A device for carrying out the method is also set forth.Type: GrantFiled: April 18, 1996Date of Patent: May 26, 1998Assignee: Fujitsu LimitedInventors: Akio Takemoto, Yoshihisa Ooaeh, Tomohiko Abe, Hiroshi Yasuda, Takamasa Satoh, Hideki Nasuno, Hidefumi Yabara, Kenichi Kawakami, Kiichi Sakamoto, Tomohiro Sakazaki, Isamu Seto, Masami Takigawa, Tatsuro Ohkawa