Patents by Inventor Robert J. Rafac
Robert J. Rafac 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: 9516729Abstract: A laser produced plasma extreme ultraviolet laser source comprising at least one variable radius mirror. The at least one variable radius mirror to adjust a beam diameter of a main pulse at a specified distance from a pre-pulse focal plane, where the pre-pulse radiates droplets into target droplets and the main pulse radiates the target droplets into a plasma state to generate the extreme ultraviolet radiation.Type: GrantFiled: July 21, 2015Date of Patent: December 6, 2016Assignee: ASML Netherlands B.V.Inventors: Kevin W Zhang, Michael Purvis, Robert J Rafac, Alexander Schafgans
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Publication number: 20160174351Abstract: A laser produced plasma extreme ultraviolet laser source comprising at least one variable radius mirror. The at least one variable radius mirror to adjust a beam diameter of a main pulse at a specified distance from a pre-pulse focal plane, where the pre-pulse radiates droplets into target droplets and the main pulse radiates the target droplets into a plasma state to generate the extreme ultraviolet radiation.Type: ApplicationFiled: July 21, 2015Publication date: June 16, 2016Inventors: Kevin W. Zhang, Michael Purvis, Robert J. Rafac, Alexander Schafgans
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Patent number: 9239269Abstract: In a laser-produced plasma (LPP) extreme ultraviolet (EUV) system, laser pulses are used to produce EUV light. To determine the energy of individual laser pulses, a photoelectromagnetic (PEM) detector is calibrated to a power meter using a calibration coefficient. When measuring a unitary laser beam comprising pulses of a single wavelength, the calibration coefficient is calculated based on a burst of the pulses. A combined laser beam has main pulses of a first wavelength alternating with pre-pulses pulses of a second wavelength. To calculate the energy of the main pulses in the combined laser beam, the calibration coefficient calculated for a unitary laser beam of the main pulses is used. To calculate the energy of the pre-pulses in the combined laser beam, a new calibration coefficient is calculated. When the calculated energy values drift beyond a pre-defined threshold, the calibration coefficients are recalculated.Type: GrantFiled: July 14, 2014Date of Patent: January 19, 2016Assignee: ASML Netherlands B.V.Inventors: Rong Liu, Robert J. Rafac, David Wayne Myers, Robert A. Bergstedt, Paul Alexander McKenzie
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Patent number: 9239268Abstract: In a laser-produced plasma (LPP) extreme ultraviolet (EUV) system, laser pulses are used to produce EUV light. To determine the energy of individual laser pulses, a photoelectromagnetic (PEM) detector is calibrated to a power meter using a calibration coefficient. When measuring a unitary laser beam comprising pulses of a single wavelength, the calibration coefficient is calculated based on a burst of the pulses. A combined laser beam has main pulses of a first wavelength alternating with pre-pulses pulses of a second wavelength. To calculate the energy of the main pulses in the combined laser beam, the calibration coefficient calculated for a unitary laser beam of the main pulses is used. To calculate the energy of the pre-pulses in the combined laser beam, a new calibration coefficient is calculated. When the calculated energy values drift beyond a pre-defined threshold, the calibration coefficients are recalculated.Type: GrantFiled: July 14, 2014Date of Patent: January 19, 2016Assignee: ASML Netherlands B.V.Inventors: Rong Liu, Robert J. Rafac, David Wayne Myers, Robert A. Bergstedt, Paul Alexander McKenzie
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Publication number: 20160011057Abstract: In a laser-produced plasma (LPP) extreme ultraviolet (EUV) system, laser pulses are used to produce EUV light. To determine the energy of individual laser pulses, a photoelectromagnetic (PEM) detector is calibrated to a power meter using a calibration coefficient. When measuring a unitary laser beam comprising pulses of a single wavelength, the calibration coefficient is calculated based on a burst of the pulses. A combined laser beam has main pulses of a first wavelength alternating with pre-pulses pulses of a second wavelength. To calculate the energy of the main pulses in the combined laser beam, the calibration coefficient calculated for a unitary laser beam of the main pulses is used. To calculate the energy of the pre-pulses in the combined laser beam, a new calibration coefficient is calculated. When the calculated energy values drift beyond a pre-defined threshold, the calibration coefficients are recalculated.Type: ApplicationFiled: July 14, 2014Publication date: January 14, 2016Inventors: Rong Liu, Robert J. Rafac, David Wayne Myers, Robert A. Bergstedt, Paul Alexander McKenzie
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Publication number: 20160011056Abstract: In a laser-produced plasma (LPP) extreme ultraviolet (EUV) system, laser pulses are used to produce EUV light. To determine the energy of individual laser pulses, a photoelectromagnetic (PEM) detector is calibrated to a power meter using a calibration coefficient. When measuring a unitary laser beam comprising pulses of a single wavelength, the calibration coefficient is calculated based on a burst of the pulses. A combined laser beam has main pulses of a first wavelength alternating with pre-pulses pulses of a second wavelength. To calculate the energy of the main pulses in the combined laser beam, the calibration coefficient calculated for a unitary laser beam of the main pulses is used. To calculate the energy of the pre-pulses in the combined laser beam, a new calibration coefficient is calculated. When the calculated energy values drift beyond a pre-defined threshold, the calibration coefficients are recalculated.Type: ApplicationFiled: July 14, 2014Publication date: January 14, 2016Inventors: Rong Liu, Robert J. Rafac, David Wayne Myers, Robert A. Bergstedt, Paul Alexander McKenzie
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Patent number: 9232623Abstract: A target material is provided at a target location, the target material including a material that emits extreme ultraviolet light when converted to plasma, and the target material extending in a first extent along a first direction and in a second extent along a second direction; an amplified light beam is directed along a direction of propagation toward the target location; and the amplified light beam is focused in a focal plane, where the target location is outside of the focal plane and an interaction between the amplified light beam and the target material converts at least part of the target material to plasma that emits EUV light.Type: GrantFiled: September 17, 2014Date of Patent: January 5, 2016Assignee: ASML Netherlands B.V.Inventors: Robert J. Rafac, Richard L. Sandstrom, Daniel Brown, Kai-Chung Hou
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Patent number: 9232624Abstract: Techniques for generating EUV light include directing a first pulse of radiation toward a target material droplet to form a modified droplet, the first pulse of radiation having an energy sufficient to alter a shape of the target material droplet; directing a second pulse of radiation toward the modified droplet to form an absorption material, the second pulse of radiation having an energy sufficient to change a property of the modified droplet, the property being related to absorption of radiation; and directing an amplified light beam toward the absorption material, the amplified light beam having an energy sufficient to convert at least a portion of the absorption material into extreme ultraviolet (EUV) light.Type: GrantFiled: August 4, 2015Date of Patent: January 5, 2016Assignee: ASML Netherlands B.V.Inventors: Robert J. Rafac, Yezheng Tao
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Publication number: 20150342016Abstract: Techniques for generating EUV light include directing a first pulse of radiation toward a target material droplet to form a modified droplet, the first pulse of radiation having an energy sufficient to alter a shape of the target material droplet; directing a second pulse of radiation toward the modified droplet to form an absorption material, the second pulse of radiation having an energy sufficient to change a property of the modified droplet, the property being related to absorption of radiation; and directing an amplified light beam toward the absorption material, the amplified light beam having an energy sufficient to convert at least a portion of the absorption material into extreme ultraviolet (EUV) light.Type: ApplicationFiled: August 4, 2015Publication date: November 26, 2015Inventors: Robert J. Rafac, Yezheng Tao
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Patent number: 9155179Abstract: Techniques for forming a target and for producing extreme ultraviolet light include releasing an initial target material toward a target location, the target material including a material that emits extreme ultraviolet (EUV) light when converted to plasma; directing a first amplified light beam toward the initial target material, the first amplified light beam having an energy sufficient to form a collection of pieces of target material from the initial target material, each of the pieces being smaller than the initial target material and being spatially distributed throughout a hemisphere shaped volume; and directing a second amplified light beam toward the collection of pieces to convert the pieces of target material to plasma that emits EUV light.Type: GrantFiled: November 21, 2014Date of Patent: October 6, 2015Assignee: ASML Netherlands B.V.Inventors: Yezheng Tao, Robert J. Rafac, Igor V. Fomenkov, Daniel J. W. Brown, Daniel J. Golich
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Patent number: 9107279Abstract: Techniques for generating EUV light include directing a first pulse of radiation toward a target material droplet to form a modified droplet, the first pulse of radiation having an energy sufficient to alter a shape of the target material droplet; directing a second pulse of radiation toward the modified droplet to form an absorption material, the second pulse of radiation having an energy sufficient to change a property of the modified droplet, the property being related to absorption of radiation; and directing an amplified light beam toward the absorption material, the amplified light beam having an energy sufficient to convert at least a portion of the absorption material into extreme ultraviolet (EUV) light.Type: GrantFiled: December 8, 2014Date of Patent: August 11, 2015Assignee: ASML Netherlands B.V.Inventors: Robert J. Rafac, Yezheng Tao
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Publication number: 20150208494Abstract: A target material is provided at a target location, the target material including a material that emits extreme ultraviolet light when converted to plasma, and the target material extending in a first extent along a first direction and in a second extent along a second direction; an amplified light beam is directed along a direction of propagation toward the target location; and the amplified light beam is focused in a focal plane, where the target location is outside of the focal plane and an interaction between the amplified light beam and the target material converts at least part of the target material to plasma that emits EUV light.Type: ApplicationFiled: September 17, 2014Publication date: July 23, 2015Inventors: Robert J. Rafac, Richard L. Sandstrom, Daniel Brown, Kai-Chung Hou
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Publication number: 20150189729Abstract: Techniques for generating EUV light include directing a first pulse of radiation toward a target material droplet to form a modified droplet, the first pulse of radiation having an energy sufficient to alter a shape of the target material droplet; directing a second pulse of radiation toward the modified droplet to form an absorption material, the second pulse of radiation having an energy sufficient to change a property of the modified droplet, the property being related to absorption of radiation; and directing an amplified light beam toward the absorption material, the amplified light beam having an energy sufficient to convert at least a portion of the absorption material into extreme ultraviolet (EUV) light.Type: ApplicationFiled: December 8, 2014Publication date: July 2, 2015Inventors: Robert J. Rafac, Yezheng Tao
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Patent number: 9000403Abstract: A method and apparatus for controlling the seed laser in a laser produced plasma (LPP) extreme ultraviolet (EUV) light system are disclosed. In one embodiment, a seed laser generates both pre-pulses and main pulses which are amplified and irradiate a target material. The widths of the main pulses are adjusted, for example by the use of an EOM or other optical switch, without adjusting the widths of the pre-pulses, to keep the EUV output energy at a desired level. Only if the main pulse widths are longer or shorter than a desired range is the duty cycle of the laser amplifier adjusted, to keep the main pulse widths in the desired range. Adjusting the main pulse widths in this way before adjusting the pump RF duty cycle allows for less adjustment of the duty cycle, thus causing less adjustment to the pre-pulses.Type: GrantFiled: February 15, 2013Date of Patent: April 7, 2015Assignee: ASML Netherlands B.V.Inventors: James Crouch, Matthew Graham, Robert J. Rafac, Daniel Jason Riggs
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Publication number: 20150076374Abstract: Techniques for forming a target and for producing extreme ultraviolet light include releasing an initial target material toward a target location, the target material including a material that emits extreme ultraviolet (EUV) light when converted to plasma; directing a first amplified light beam toward the initial target material, the first amplified light beam having an energy sufficient to form a collection of pieces of target material from the initial target material, each of the pieces being smaller than the initial target material and being spatially distributed throughout a hemisphere shaped volume; and directing a second amplified light beam toward the collection of pieces to convert the pieces of target material to plasma that emits EUV light.Type: ApplicationFiled: November 21, 2014Publication date: March 19, 2015Inventors: Yezheng Tao, Robert J. Rafac, Igor V. Fomenkov, Daniel J.W. Brown, Daniel J. Golich
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Patent number: 8927952Abstract: Techniques for generating EUV light include directing a first pulse of radiation toward a target material droplet to form a modified droplet, the first pulse of radiation having an energy sufficient to alter a shape of the target material droplet; directing a second pulse of radiation toward the modified droplet to form an absorption material, the second pulse of radiation having an energy sufficient to change a property of the modified droplet, the property being related to absorption of radiation; and directing an amplified light beam toward the absorption material, the amplified light beam having an energy sufficient to convert at least a portion of the absorption material into extreme ultraviolet (EUV) light.Type: GrantFiled: January 10, 2014Date of Patent: January 6, 2015Assignee: ASML Netherlands B.V.Inventors: Robert J. Rafac, Yezheng Tao
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Patent number: 8912514Abstract: Techniques for forming a target and for producing extreme ultraviolet light include releasing an initial target material toward a target location, the target material including a material that emits extreme ultraviolet (EUV) light when converted to plasma; directing a first amplified light beam toward the initial target material, the first amplified light beam having an energy sufficient to form a collection of pieces of target material from the initial target material, each of the pieces being smaller than the initial target material and being spatially distributed throughout a hemisphere shaped volume; and directing a second amplified light beam toward the collection of pieces to convert the pieces of target material to plasma that emits EUV light.Type: GrantFiled: June 20, 2014Date of Patent: December 16, 2014Assignee: ASML Netherlands B.V.Inventors: Yezheng Tao, Robert J. Rafac, Igor V. Fomenkov, Daniel J. W. Brown, Daniel J. Golich
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Patent number: 8872143Abstract: Techniques for generating EUV light include directing a first pulse of radiation toward a target material droplet to form a modified droplet, the first pulse of radiation having an energy sufficient to alter a shape of the target material droplet; directing a second pulse of radiation toward the modified droplet to form an absorption material, the second pulse of radiation having an energy sufficient to change a property of the modified droplet, the property being related to absorption of radiation; and directing an amplified light beam toward the absorption material, the amplified light beam having an energy sufficient to convert at least a portion of the absorption material into extreme ultraviolet (EUV) light.Type: GrantFiled: March 14, 2013Date of Patent: October 28, 2014Assignee: ASML Netherlands B.V.Inventors: Robert J. Rafac, Yezheng Tao
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Publication number: 20140299791Abstract: Techniques for forming a target and for producing extreme ultraviolet light include releasing an initial target material toward a target location, the target material including a material that emits extreme ultraviolet (EUV) light when converted to plasma; directing a first amplified light beam toward the initial target material, the first amplified light beam having an energy sufficient to form a collection of pieces of target material from the initial target material, each of the pieces being smaller than the initial target material and being spatially distributed throughout a hemisphere shaped volume; and directing a second amplified light beam toward the collection of pieces to convert the pieces of target material to plasma that emits EUV light.Type: ApplicationFiled: June 20, 2014Publication date: October 9, 2014Inventors: Yezheng Tao, Robert J. Rafac, Igor V. Fomenkov, Daniel J.W. Brown, Daniel J. Golich
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Patent number: RE45957Abstract: A laser includes a regenerative ring resonator that includes a discharge chamber having electrodes and a gain medium between the electrodes for producing a laser beam; a partially-reflective optical coupler, and a beam modification optical system in the path of the laser beam. The beam modification optical system transversely expands a profile of the laser beam such that the near field laser beam profile uniformly fills each aperture within the laser and such that the regenerative ring resonator remains either conditionally stable or marginally unstable when operating the laser at powers that induce thermal lenses in optical elements inside the regenerative ring resonator.Type: GrantFiled: March 6, 2013Date of Patent: March 29, 2016Assignee: Cymer, LLCInventors: Hong Ye, Richard L. Sandstrom, Rostislav Rokitski, Daniel J. W. Brown, Robert J. Rafac