Patents by Inventor Ken Ozawa
Ken Ozawa 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: 6730925Abstract: An exposure method is provided so that the dividend regions defined on a wafer are successively exposed using pulses of laser light emitted from an excimer laser light source in such a way that each region receives a different level of target exposure levels. And, transmittance of a course energy adjuster, having a number of neutral density filters, is adjusted so that a sub-divided region receiving the least number of exposure pulses can receive a pulse count that exceeds the minimum number of exposure pulses required for optimal exposure. During the process of scanning exposure, transmittance of the coarse energy adjuster is held constant so that, to compensate for variations in the pulse energy, the output power of the excimer laser light source is adjusted according to real-time data output from an integrator sensor.Type: GrantFiled: November 15, 2000Date of Patent: May 4, 2004Assignee: Nikon CorporationInventor: Ken Ozawa
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Patent number: 6721039Abstract: In an exposure method which illuminates a first object with an exposure beam and exposes a second object through a projection system with the exposure beam passing through a pattern of the first object, a correlation between a light amount of the exposure beam detected at a measuring point on an optical path to the first object and a light amount of the exposure beam on an image plane of the projection system is previously obtained, and when an integrated exposure amount with respect to the second object is controlled based on the light amount of the exposure beam detected at the measuring point and the correlation at the time of exposure of the second object, a variation amount of transmittance of the projection system is forecast in accordance with a process condition and exposure progression, and the correlation is renewed based on the forecast variation amount of the transmittance.Type: GrantFiled: January 11, 2001Date of Patent: April 13, 2004Assignee: Nikon CorporationInventor: Ken Ozawa
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Publication number: 20030201484Abstract: A semiconductor capacitor configured so as to use buried wirings, as electrodes, formed in an interlayer dielectric is provided on a semiconductor substrate which is capable of preventing an increase in a number of manufacturing processes with occurrence of parasitic capacity being suppressed. The semiconductor capacitor has a capacitive insulating film made up of an etching stopper film formed only in a region being sandwiched between a via plug serving as an upper electrode and a lower electrode, in which the capacitive insulating film is not formed in a region other than the facing region.Type: ApplicationFiled: April 23, 2003Publication date: October 30, 2003Applicant: NEC Electronics CorporationInventor: Ken Ozawa
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Patent number: 6538723Abstract: In a scanning exposure apparatus and method, a pattern formed on a mask is transferred onto a substrate by scanning the mask and the substrate synchronously with respect to pulsed light emitted from a pulsed laser light source. A number of pulses of a light beam that are to be emitted to each point on the substrate during scanning exposure is determined, and the light source is controlled according to the determined number of pulses, so that the maximum scanning speeds of the mask and the substrate and/or the maximum oscillation period of the pulsed light are maintained during the scanning exposure process. In another arrangement, during the process of exposing a shot area on the substrate, integral values of the amount of exposure energy are detected at a plurality of points in that shot area. Based on this detection result, the oscillation frequency of the pulsed light that is to be emitted to the next shot area is determined so that the next shot area is exposed at an appropriate exposure level.Type: GrantFiled: July 12, 1999Date of Patent: March 25, 2003Assignee: Nikon CorporationInventors: Shigeru Hagiwara, Ken Ozawa
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Patent number: 6501535Abstract: In an exposure control method and apparatus, pulsed illumination light from an excimer laser light source is reduced by an energy rough modulator before illuminating a reticle. The reticle and a wafer are moved or scanned relative to a projection optical system to sequentially transfer a pattern image of the reticle to individual shot areas on a wafer. An integrator sensor indirectly monitors the amount of exposure on the wafer, and an energy monitor monitors the energy of pulsed illumination light inside the excimer laser light source. Based on the result of measurement by the integrator sensor and the correlation between the result of measurement by the integrator sensor and the result of measurement by the energy monitor, the emission power of the excimer laser light source is finely modulated at a high speed without employing an energy fine modulator that finely modulates the transmittance by a mechanical drive and without causing an energy loss along the optical path of illumination light.Type: GrantFiled: January 6, 2000Date of Patent: December 31, 2002Assignee: Nikon CorporationInventor: Ken Ozawa
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Publication number: 20020196418Abstract: In a scanning exposure apparatus and method, a pattern formed on a mask is transferred onto a substrate by scanning the mask and the substrate synchronously with respect to pulsed light emitted from a pulsed laser light source. A number of pulses of a light beam that are to be emitted to each point on the substrate during scanning exposure is determined, and the light source is controlled according to the determined number of pulses, so that the maximum scanning speeds of the mask and the substrate and/or the maximum oscillation period of the pulsed light are maintained during the scanning exposure process. In another arrangement, during the process of exposing a shot area on the substrate, integral values of the amount of exposure energy are detected at a plurality of points in that shot area. Based on this detection result, the oscillation frequency of the pulsed light that is to be emitted to the next shot area is determined so that the next shot area is exposed at an appropriate exposure level.Type: ApplicationFiled: July 12, 1999Publication date: December 26, 2002Inventors: SHIGERU HAGIWARA, KEN OZAWA
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Publication number: 20010035945Abstract: In an exposure method which illuminates a first object with an exposure beam and exposes a second object through a projection system with the exposure beam passing through a pattern of the first object, a correlation between a light amount of the exposure beam detected at a measuring point on an optical path to the first object and a light amount of the exposure beam on an image plane of the projection system is previously obtained, and when an integrated exposure amount with respect to the second object is controlled based on the light amount of the exposure beam detected at the measuring point and the correlation at the time of exposure of the second object, a variation amount of transmittance of the projection system is forecast in accordance with a process condition and exposure progression, and the correlation is renewed based on the forecast variation amount of the transmittance.Type: ApplicationFiled: January 11, 2001Publication date: November 1, 2001Applicant: NIkon CorporationInventor: Ken Ozawa
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Patent number: 6154269Abstract: In a scan type exposure apparatus which provides relative movement between an exposure beam and an object in a predetermined direction to expose the object, performance of the apparatus is evaluated by a method that comprises detecting the exposure beam under an operation condition to be used in a scan exposure for the object, and evaluating the performance of the apparatus based on information obtained by detecting the exposure beam. The operation condition may be one that causes unevenness in the integrated exposure amount for the object to be exposed or movement speed of a movable member holding the object. The detecting may involve the detection of exposure beam pulses.Type: GrantFiled: November 13, 1998Date of Patent: November 28, 2000Assignee: Nikon CorporationInventor: Ken Ozawa
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Patent number: 6154270Abstract: A scanning exposure method is arranged to illuminate a mask with light pulses and to synchronously scan the mask and a photosensitive substrate so as to effect scanning exposure of a pattern image of the mask on the photosensitive substrate, and includes detecting energy amounts of light pulses illuminating the mask during the scanning exposure, successively calculating an integrated amount of light of the last N pulses (N is an integer more than one) for every unit pulse number, based on the energy amounts thus detected and adjusting an exposure dose on the photosensitive substrate in accordance with a sequence of integrated amounts of light thus calculated.Type: GrantFiled: July 19, 1999Date of Patent: November 28, 2000Assignee: Nikon CorporationInventor: Ken Ozawa
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Patent number: 6124064Abstract: Projection for evaluation is carried out prior to actual projection according to a predetermined projection sequence without performing shot-by-shot light exposure control to measure average pulse energy p(i) through an integrator sensor every shot area. Then set pulse energy S.sub.0 /N is divided by the average pulse energy p(i), thereby calculating correction coefficients t(i) (=S.sub.0 /p(i).multidot.N)) of pulse energy for the i-th shot areas and thus producing a correction data map upon actual projection on the i-th shot area, an adjustment amount obtained by multiplying an adjustment amount before correction by the correction coefficient t(i) is used as an adjustment amount in an energy fine adjuster.Type: GrantFiled: February 13, 1998Date of Patent: September 26, 2000Assignee: Nikon CorporationInventor: Ken Ozawa
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Patent number: 5965308Abstract: The exposure quantity with respect to a wafer is correctly measured under each illumination condition even when illumination conditions are changed over. Under each of conditions where the .sigma. value (coherence factor) of an illumination optical system is set to various values including its small, standard, and large values, a correlation data between the output (E) of a reference illuminance meter and the output (I) of an integrator sensor is obtained. With respect to the correlation data for the respective .sigma. values, approximate lines (24A, 24B, 24C, etc) are determined by the method of least squares and then gradients of these lines are stored as correlation coefficients (.alpha.). Under the illumination condition corresponding to each .sigma. value, the output (I) of the integrator sensor is divided by its corresponding correlation coefficient (.alpha.) so as to compute the exposure energy on the image surface.Type: GrantFiled: March 29, 1996Date of Patent: October 12, 1999Assignee: Nixon CorporationInventor: Ken Ozawa
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Patent number: 5929977Abstract: The illuminance of illumination light from an exposure light source is switched over in a plurality of steps in an open loop control, whereby, when a plurality of shot areas on one substrate to be exposed to light are exposed to the light with various integrated exposure quantities, the exposure quantity with respect to each shot area is correctly controlled. Pulse illumination light from an excimer laser light source is attenuated by a rough energy adjuster and a fine energy adjuster and then illuminates a reticle, while the reticle and a wafer are scanned with respect to a projection optical system, such that a pattern of the reticle is successively transferred to individual shot areas on the wafer. When the extinction ratio of the rough energy adjuster is switched over in an open loop control, the illuminance on the image surface is measured by an illuminance fluctuation sensor so as to adjust, based on the result of this measurement, the illuminance on the image surface.Type: GrantFiled: August 15, 1997Date of Patent: July 27, 1999Assignee: Nikon CorporationInventor: Ken Ozawa
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Patent number: 5898480Abstract: An exposure method wherein a mask on which a pattern is formed is illuminated with a slit-like illumination light beam, and the mask and a substrate are caused to scan the slit-like illumination light beam in a scanning direction in order to form an image of the pattern on the substrate, and wherein photo-electric signals obtained by a sensor which moves in the scanning direction, relative to the slit-like illumination light beam, and photo-electric signals obtained from the sensor which moves in a direction orthogonal to the scanning direction are integrated so as to obtain integrated values thereof, and an unevenness among the integrated values relating to a direction orthogonal to the scanning direction is calculatedType: GrantFiled: December 26, 1996Date of Patent: April 27, 1999Assignee: Nikon CorporationInventor: Ken Ozawa
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Patent number: 5728495Abstract: A scanning exposure method is arranged to illuminate a mask with light pulses and to synchronously scan the mask and a photosensitive substrate so as to effect scanning exposure of a pattern image of the mask on the photosensitive substrate, and comprises detecting energy amounts of light pulses illuminating the mask during the scanning exposure, successively calculating an integrated amount of light of the last N pulses (N is an integer more than one) for every unit pulse number, based on the energy amounts thus detected and adjusting an exposure dose on the photosensitive substrate in accordance with a sequence of integrated amounts of light thus calculated.Type: GrantFiled: December 1, 1995Date of Patent: March 17, 1998Assignee: Nikon CorporationInventor: Ken Ozawa
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Patent number: 5659383Abstract: The illuminance of illumination light from an exposure light source is switched over in a plurality of steps in an open loop control, whereby, when a plurality of shot areas on one substrate to be exposed to light are exposed to the light with various integrated exposure quantities, the exposure quantity with respect to each shot area is correctly controlled. Pulse illumination light from an excimer laser light source is attenuated by a rough energy adjuster and a fine energy adjuster and then illuminates a reticle, while the reticle and a wafer are scanned with respect to a projection optical system, such that a pattern of the reticle is successively transferred to individual shot areas on the wafer. When the extinction ratio of the rough energy adjuster is switched over in an open loop control, the illuminance on the image surface is measured by an illuminance fluctuation sensor so as to adjust, based on the result of this measurement, the illuminance on the image surface.Type: GrantFiled: March 29, 1996Date of Patent: August 19, 1997Assignee: Nikon CorporationInventor: Ken Ozawa
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Patent number: 5574537Abstract: An apparatus for controlling a light quantity comprises a light source for emitting light and an acousto optical modulating element, having a driving unit for giving a progressive wave to a medium, for generating 0th-order and higher-order diffracted beams of light by an acousto optical effect of the progressive wave. The apparatus also comprises a stop element which transmits, not the higher-order diffracted beams, but the 0th-order diffracted beam; and a drive controlling section for varying a quantity of light irradiating an object by regulating the progressive wave through the driving unit.Type: GrantFiled: April 13, 1994Date of Patent: November 12, 1996Assignee: Nikon CorporationInventor: Ken Ozawa
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Patent number: 5534970Abstract: A projection exposure apparatus for transferring a pattern formed on a mask onto a photosensitive substrate by a scanning exposure method, includes a light source for generating a light beam having a predetermined spatial coherence, an illumination optical system for receiving the light beam from the light source and illuminating a local area on the mask with the light beam, and a device for synchronously moving the mask and the photosensitive substrate so as to transfer the pattern on the mask onto the photosensitive substrate. A direction, corresponding to a higher spatial coherence of the light beam, is made to coincide with the direction of relative scanning an illumination area and the mask in the illumination area.Type: GrantFiled: June 7, 1994Date of Patent: July 9, 1996Assignee: Nikon CorporationInventors: Toshiharu Nakashima, Masato Hamatani, Ken Ozawa
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Patent number: 5473412Abstract: The average number N of coarse exposure pulses is obtained by dividing a proper exposure amount to a wafer by the average pulse energy. Under a condition that the average number N of coarse exposure pulses is equal to or more than the minimum number of pulses N.sub.min, the achievement accuracy R is calculated by dividing the actual accumulated exposure amount to the wafer by the proper exposure amount and the coarse exposure is performed until the achievement accuracy R reaches the coarse exposure finish judgment level Rc. Thereafter, the attenuating rate for pulse lights is set to be a predetermined value and the correcting exposure is performed by the cutoff control method until the achievement accuracy R reaches the correction exposure finish judgment level Rcc.Type: GrantFiled: February 27, 1995Date of Patent: December 5, 1995Assignee: Nikon CorporationInventor: Ken Ozawa
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Patent number: 5044891Abstract: A power source (14) rotates an eccentric (20) engaged within the center of a relatively large drive roller (22) to rotate the drive roller while simultaneously orbiting the center of the drive roller about a circular path so as to cyclically advance and retract from piston assemblies (24) located within pump assemblies (16a-16d). Rotation of the eccentric (20) causes each piston assembly (24) to cyclically advance against and retract from a flexible diaphragm (26) to cause fluid entering the pump assembly to be forced out under pressure. Each diaphragm (26) is "backed" by a spring-loaded support (27) that resiliently pushes against the side of the diaphragm opposite the piston assembly.Type: GrantFiled: August 14, 1989Date of Patent: September 3, 1991Assignee: Ozawa R&D, Inc.Inventor: Ken Ozawa
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Patent number: RE37309Abstract: A projection exposure apparatus for transferring a pattern formed on a mask onto a photosensitive substrate by a scanning exposure method, includes a light source for generating a light beam having a predetermined spatial coherence, an illumination optical system for receiving the light beam from the light source and illuminating a local area on the mask with the light beam, and a device for synchronously moving the mask and the photosensitive substrate so as to transfer the pattern on the mask onto the photosensitive substrate. A direction, corresponding to a higher spatial coherence of the light beam, is made to coincide with the direction of relative scanning an illumination area and the mask in the illumination area.Type: GrantFiled: July 9, 1998Date of Patent: August 7, 2001Assignee: Nikon CorporationInventors: Toshiharu Nakashima, Masato Hamatani, Ken Ozawa