Patents by Inventor Gaurav Keswani
Gaurav Keswani 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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Publication number: 20220057017Abstract: A valve (10) for selectively opening and closing a flow passageway (12) includes (i) a valve body (14) that defines a body passageway (16); (ii) a first valve surface (18) that defines a first valve opening (18A); (iii) an expandable barrier (22); and (iv) an actuation system (24). The expandable barrier (22) is movable in the body passageway (16) between an open configuration (30) in which the barrier (22) is retracted and does not engage the first valve surface (18); and a closed configuration (28) in which the barrier (22) is expanded, engages the first valve surface (18), and blocks the first valve opening (18A). The actuation system (24) selectively moves the barrier (22) between the configurations (28) (30).Type: ApplicationFiled: August 18, 2021Publication date: February 24, 2022Inventors: Alex Ka Tim Poon, Michael Birk Binnard, Gaurav Keswani
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Patent number: 11092170Abstract: A stage assembly (10) includes a stage (14), and a fluid actuator assembly (24) that moves the stage (14). The fluid actuator assembly (24) includes a piston housing (32) that defines a piston chamber (34); (ii) a piston (36) that separates the piston chamber (34) into a first chamber (34A) and a second chamber (34B); (iii) a supply valve (38C) that controls the flow of the working fluid (40) into the first chamber (34A); and (iv) an exhaust valve (38D) that controls the flow of the working fluid (40) out of the first chamber (34A). The supply valve (38C) has a supply orifice (250G) having a supply orifice area, and the exhaust valve (38D) has an exhaust orifice (352G) having an exhaust orifice area. Moreover, the supply orifice area is different from the exhaust orifice area. Further multiple valves of different sizes can be used in combination for the supply and exhaust for each chamber (34A), (34B).Type: GrantFiled: February 12, 2018Date of Patent: August 17, 2021Inventors: Alex Ka Tim Poon, Yeong-Jun Choi, Pai-Hsueh Yang, Sandy Lee, Gaurav Keswani, Rocky Mai
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Publication number: 20190376531Abstract: A stage assembly (10) includes a stage (14), and a fluid actuator assembly (24) that moves the stage (14). The fluid actuator assembly (24) includes a piston housing (32) that defines a piston chamber (34); (ii) a piston (36) that separates the piston chamber (34) into a first chamber (34A) and a second chamber (34B); (iii) a supply valve (38C) that controls the flow of the working fluid (40) into the first chamber (34A); and (iv) an exhaust valve (38D) that controls the flow of the working fluid (40) out of the first chamber (34A). The supply valve (38C) has a supply orifice (250G) having a supply orifice area, and the exhaust valve (38D) has an exhaust orifice (352G) having an exhaust orifice area. Moreover, the supply orifice area is different from the exhaust orifice area. Further multiple valves of different sizes can be used in combination for the supply and exhaust for each chamber (34A), (34B).Type: ApplicationFiled: February 12, 2018Publication date: December 12, 2019Inventors: Alex Ka Tim Poon, Yeong-Jun Choi, Pai-Hsueh Yang, Sandy Lee, Gaurav Keswani, Rocky Mai
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Patent number: 9217933Abstract: A lithographic projection apparatus includes a stage assembly having a substrate table on which a substrate is supported and exposed with an exposure beam from a final optical element of a projection optical assembly through an immersion liquid. A confinement member encircles a portion of a path of the exposure beam and has an aperture through which the exposure beam is projected. A movable member is movable in a space between the confinement member and the substrate, the substrate table, or both, such that a first portion of the space is located between a first surface of the movable member and the confinement member, and a second portion of the space is located between a second surface of the movable member and the substrate, the substrate table, or both.Type: GrantFiled: April 25, 2014Date of Patent: December 22, 2015Assignee: NIKON CORPORATIONInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani, Derek Coon, Daishi Tanaka
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Patent number: 9176394Abstract: An immersion lithography apparatus that includes a substrate holder on which a substrate is held, a projection system having a final optical element and that projects an exposure beam onto the substrate through an immersion liquid, and a liquid confinement member having an aperture through which the exposure beam is projected, a lower surface including a non-fluid removal area surrounding the aperture, and a liquid recovery outlet from which the immersion liquid is recovered, also includes a movable member. The movable member is movable relative to the liquid confinement member in a substantially horizontal direction, and has an opening through which the exposure beam is projected. The movable member has upper and lower surfaces that surround the opening, and is movable while a portion of the upper surface faces the non-fluid removal area in the lower surface of the liquid confinement member.Type: GrantFiled: November 18, 2013Date of Patent: November 3, 2015Assignee: NIKON CORPORATIONInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Derek Coon, Gaurav Keswani, Daishi Tanaka
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Patent number: 8934080Abstract: An immersion lithography apparatus includes a projection system having a final optical element, a movable stage that is movable below the projection system such that a gap exists between the final optical element and a surface of the stage, an immersion liquid being filled in the gap, a liquid confinement member and a liquid diverter. The liquid confinement member maintains the immersion liquid in the gap, and includes a liquid recovery portion that faces the stage surface and recovers liquid from the gap. The liquid recovery portion includes a first porous portion through which a first suction force is applied and a second porous portion through which a second suction force less than the first suction force is applied, the second portion being located outward of the first portion. The liquid diverter is positioned between the stage and at least the first porous portion.Type: GrantFiled: September 14, 2012Date of Patent: January 13, 2015Assignee: Nikon CorporationInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Derek Coon, Gaurav Keswani
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Publication number: 20140232999Abstract: A lithographic projection apparatus includes a stage assembly having a substrate table on which a substrate is supported and exposed with an exposure beam from a final optical element of a projection optical assembly through an immersion liquid. A confinement member encircles a portion of a path of the exposure beam and has an aperture through which the exposure beam is projected. A movable member is movable in a space between the confinement member and the substrate, the substrate table, or both, such that a first portion of the space is located between a first surface of the movable member and the confinement member, and a second portion of the space is located between a second surface of the movable member and the substrate, the substrate table, or both.Type: ApplicationFiled: April 25, 2014Publication date: August 21, 2014Applicant: NIKON CORPORATIONInventors: Alex Ka Tim POON, Leonard Wai Fung KHO, Gaurav KESWANI, Derek COON, Daishi TANAKA
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Patent number: 8780323Abstract: Immersion fluid remaining on a portion of a substrate after that portion has passed an immersion nozzle is removed by moving the substrate relative to an immersion nozzle so that the portion of the substrate on which the immersion fluid remains is passed by the immersion nozzle again. A path is determined along which the substrate is to be moved to remove the remaining immersion fluid. The path can be determined based upon previous movements of the substrate, including factors such as the speed and/or length of the previous movements. Alternatively, portions of the substrate on which immersion fluid remains can be detected, and then the substrate can be moved so that the portion of the substrate on which the immersion fluid remains is passed by the immersion nozzle based on the results of the detection. Immersion fluid also can be removed from the stage surface located beyond the substrate.Type: GrantFiled: March 11, 2011Date of Patent: July 15, 2014Assignee: Nikon CorporationInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani
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Patent number: 8743343Abstract: A lithographic projection apparatus includes a projection optical assembly having a final optical element, a stage assembly including a substrate table on which a substrate is supported, the substrate supported by the substrate table being exposed with an exposure beam from the final optical element of the projection optical assembly through an immersion liquid, a confinement member which encircles a portion of a path of the exposure beam, and a movable member which is movable in a space between the confinement member and the substrate, the substrate table, or both, the space being divided by the movable member into a first portion between the confinement member and the movable member and a second portion between the movable member and the substrate, the substrate table, or both. The movable member has a recovery outlet from which the immersion liquid in the second portion is removed.Type: GrantFiled: January 30, 2013Date of Patent: June 3, 2014Assignee: Nikon CorporationInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani, Derek Coon, Daishi Tanaka
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Publication number: 20140071412Abstract: An immersion lithography apparatus that includes a substrate holder on which a substrate is held, a projection system having a final optical element and that projects an exposure beam onto the substrate through an immersion liquid, and a liquid confinement member having an aperture through which the exposure beam is projected, a lower surface including a non-fluid removal area surrounding the aperture, and a liquid recovery outlet from which the immersion liquid is recovered, also includes a movable member. The movable member is movable relative to the liquid confinement member in a substantially horizontal direction, and has an opening through which the exposure beam is projected. The movable member has upper and lower surfaces that surround the opening, and is movable while a portion of the upper surface faces the non-fluid removal area in the lower surface of the liquid confinement member.Type: ApplicationFiled: November 18, 2013Publication date: March 13, 2014Applicant: NIKON CORPORATIONInventors: Alex Ka Tim POON, Leonard Wai Fung KHO, Derek COON, Gaurav KESWANI, Daishi TANAKA
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Patent number: 8634055Abstract: An immersion liquid confinement apparatus recovers an immersion liquid from an immersion area that includes a gap between a projection system and an object of exposure in an immersion lithography system. The apparatus includes a confinement member that includes an outlet and an aperture through which a patterned image is projected onto the object. A first liquid-permeable member covers the outlet and has a first surface that faces the object and a second surface opposite the first surface, the second surface contacting a first chamber. A second liquid-permeable member has first and second oppositely-facing surfaces, the first surface of the second liquid-permeable member contacts the first chamber, the second surface of the second liquid-permeable member contacts a second chamber that is different from the first chamber. A hydrophobic porous member is provided between the first chamber and a vacuum system that supplies a low pressure to the first chamber.Type: GrantFiled: February 2, 2010Date of Patent: January 21, 2014Assignee: Nikon CorporationInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Derek Coon, Gaurav Keswani
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Patent number: 8610873Abstract: An immersion lithography apparatus includes a projection system having a final optical element and a stage that is movable to a position below the projection system such that a gap exists between the final optical element and a surface of the stage. An immersion liquid fills the gap between the surface and the final optical element. A liquid confinement member maintains the immersion liquid in the gap. The immersion liquid has a meniscus where the liquid contacts ambient gas, the meniscus defining a footprint of an immersion area. A movable liquid diverter is positioned between the liquid confinement member and the stage. The movable liquid diverter moves relative to the liquid confinement member in a direction parallel to the surface of the stage, and includes an opening that surrounds the immersion area, the opening contacting or being slightly spaced from the immersion area when the stage is stationary.Type: GrantFiled: March 9, 2009Date of Patent: December 17, 2013Assignee: Nikon CorporationInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Derek Coon, Gaurav Keswani, Daishi Tanaka
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Patent number: 8400610Abstract: Apparatus and methods keep immersion liquid in a space adjacent to an optical assembly. An optical assembly projects an image onto a substrate supported adjacent to the optical assembly by a substrate table. An insertion member insertable into the space between the optical assembly and the substrate, the substrate table, or both, divides the immersion liquid into a first portion and a second portion, the first portion disposed between the optical assembly and the insertion member, and the second portion disposed between the insertion member and the substrate, the substrate table, or both. The insertion member keeps the optical assembly in contact with the first portion when the substrate is moved away from being disposed adjacent to the optical assembly.Type: GrantFiled: June 25, 2012Date of Patent: March 19, 2013Assignee: Nikon CorporationInventors: Alex Poon, Leonard Kho, Gaurav Keswani, Derek Coon, Daishi Tanak
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Publication number: 20130010271Abstract: An immersion lithography apparatus includes a projection system having a final optical element, a movable stage that is movable below the projection system such that a gap exists between the final optical element and a surface of the stage, an immersion liquid being filled in the gap, a liquid confinement member and a liquid diverter. The liquid confinement member maintains the immersion liquid in the gap, and includes a liquid recovery portion that faces the stage surface and recovers liquid from the gap. The liquid recovery portion includes a first porous portion through which a first suction force is applied and a second porous portion through which a second suction force less than the first suction force is applied, the second portion being located outward of the first portion. The liquid diverter is positioned between the stage and at least the first porous portion.Type: ApplicationFiled: September 14, 2012Publication date: January 10, 2013Applicant: NIKON CORPORATIONInventors: Alex Ka Tim POON, Leonard Wai Fung KHO, Derek COON, Gaurav KESWANI
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Publication number: 20120262687Abstract: Apparatus and methods keep immersion liquid in a space adjacent to an optical assembly. An optical assembly projects an image onto a substrate supported adjacent to the optical assembly by a substrate table. An insertion member insertable into the space between the optical assembly and the substrate, the substrate table, or both, divides the immersion liquid into a first portion and a second portion, the first portion disposed between the optical assembly and the insertion member, and the second portion disposed between the insertion member and the substrate, the substrate table, or both. The insertion member keeps the optical assembly in contact with the first portion when the substrate is moved away from being disposed adjacent to the optical assembly.Type: ApplicationFiled: June 25, 2012Publication date: October 18, 2012Applicant: NIKON CORPORATIONInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani, Derek Coon
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Patent number: 8289497Abstract: An immersion lithography apparatus includes a projection system having a final optical element, a movable stage that is movable below the projection system such that a gap exists between the final optical element and a surface of the stage, an immersion liquid being filled in the gap, a liquid confinement member and a liquid diverter. The liquid confinement member maintains the immersion liquid in the gap, and includes a liquid recovery portion that faces the stage surface and recovers liquid from the gap. The liquid recovery portion includes a first porous portion through which a first suction force is applied and a second porous portion through which a second suction force less than the first suction force is applied, the second portion being located outward of the first portion. The liquid diverter is positioned between the stage and at least the first porous portion.Type: GrantFiled: February 20, 2009Date of Patent: October 16, 2012Assignee: Nikon CorporationInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Derek Coon, Gaurav Keswani
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Patent number: 8237911Abstract: Apparatus and methods keep immersion liquid in a space adjacent to an optical assembly. An optical assembly projects an image onto a substrate supported adjacent to the optical assembly by a substrate table. An insertion member insertable into the space between the optical assembly and the substrate, the substrate table, or both, divides the immersion liquid into a first portion and a second portion, the first portion disposed between the optical assembly and the insertion member, and the second portion disposed between the insertion member and the substrate, the substrate table, or both. The insertion member keeps the optical assembly in contact with the first portion when the substrate is moved away from being disposed adjacent to the optical assembly.Type: GrantFiled: October 29, 2007Date of Patent: August 7, 2012Assignee: Nikon CorporationInventors: Alex Poon, Leonard Kho, Gaurav Keswani, Derek Coon
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Publication number: 20120062866Abstract: Electromagnetic actuators are disclosed having at least one actively cooled coil assembly. Exemplary actuators are linear and planar motors of which the cooled coil assembly has a coil having first and second main surfaces. A respective thermally conductive cooling plate is in thermal contact with at least one main surface of the coil. Defined in or on each cooling plate is a coolant passageway that conducts a liquid coolant. A primary pattern of the coolant passageway is coextensive with at least part of the main surface of the coil. The primary pattern can have a secondary pattern through which coolant flows in a manner reducing eddy-current losses. An exemplary secondary pattern is serpentine. An exemplary primary pattern is radial or has a radial aspect, such as an X-shaped pattern. The devices exhibit reduced eddy-current drag.Type: ApplicationFiled: September 2, 2011Publication date: March 15, 2012Inventors: Michael B. Binnard, Scott Coakley, Alex Ka Tim Poon, Masahiro Totsu, Derek Coon, Leonard Wai Fung Kho, Gaurav Keswani, Alexander Cooper, Michel Pharand, Matt Bjork
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Publication number: 20110164239Abstract: Immersion fluid remaining on a portion of a substrate after that portion has passed an immersion nozzle is removed by moving the substrate relative to an immersion nozzle so that the portion of the substrate on which the immersion fluid remains is passed by the immersion nozzle again. A path is determined along which the substrate is to be moved to remove the remaining immersion fluid. The path can be determined based upon previous movements of the substrate, including factors such as the speed and/or length of the previous movements. Alternatively, portions of the substrate on which immersion fluid remains can be detected, and then the substrate can be moved so that the portion of the substrate on which the immersion fluid remains is passed by the immersion nozzle based on the results of the detection. Immersion fluid also can be removed from the stage surface located beyond the substrate.Type: ApplicationFiled: March 11, 2011Publication date: July 7, 2011Applicant: NIKON CORPORATIONInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani
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Patent number: 7929109Abstract: Immersion fluid remaining on a portion of a substrate after that portion has passed an immersion nozzle is removed by moving the substrate relative to an immersion nozzle so that the portion of the substrate on which the immersion fluid remains is passed by the immersion nozzle again. A path is determined along which the substrate is to be moved to remove the remaining immersion fluid. The path can be determined based upon previous movements of the substrate, including factors such as the speed and/or length of the previous movements. Alternatively, portions of the substrate on which immersion fluid remains can be detected, and then the substrate can be moved so that the portion of the substrate on which the immersion fluid remains is passed by the immersion nozzle based on the results of the detection. Immersion fluid also can be removed from the stage surface located beyond the substrate.Type: GrantFiled: October 19, 2006Date of Patent: April 19, 2011Assignee: Nikon CorporationInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani