Li-Jui Chen 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).
Abstract: In accordance with some embodiments, a method of controlling an extreme ultraviolet (EUV) radiation in lithography system is provided. The method includes generating a plurality of target droplets. The method also includes generating a pre-pulse and a main pulse from an excitation laser module to generate EUV light and reflecting the EUV light by a collector mirror. The method further includes measuring a separation between a pre-pulse and a main pulse. Moreover, the method includes determining whether the separation between the pre-pulse and the main pulse in the y-axis is changed, if not adjusting a configurable parameter of the excitation laser module to set the variation in the energy of the EUV light within an acceptable range.
Abstract: An extreme ultraviolet (EUV) lithography system includes a vane bucket module. The vane bucket module includes a temperature adjusting pack and a collecting tank inserted into the temperature adjusting pack. The temperature adjusting pack has a plurality of inlets. The collecting tank has a cover and the cover includes a plurality of through holes. The inlets of the temperature adjusting pack are aligned with the through holes of the cover. Thicknesses of edges of the cover is different from a thickness of a center of the cover.
Abstract: A lithography mask includes a substrate that contains a low thermal expansion material (LTEM). The lithography mask also includes a reflective structure disposed over the substrate. The reflective structure includes a first layer and a second layer disposed over the first layer. At least the second layer is porous. The mask is formed by forming a multilayer reflective structure over the LTEM substrate, including forming a plurality of repeating film pairs, where each film pair includes a first layer and a porous second layer. A capping layer is formed over the multilayer reflective structure. An absorber layer is formed over the capping layer.
Abstract: A photolithography system utilizes tin droplets to generate extreme ultraviolet radiation for photolithography. The photolithography system irradiates the droplets with a laser. The droplets become a plasma and emit extreme ultraviolet radiation. The photolithography system senses contamination of a collector mirror by the tin droplets and adjusts the flow of a buffer fluid to reduce the contamination.
Abstract: A droplet generator includes a steering system, a reservoir, a nozzle, a first heater, a second heater and a third heater. The steering system is used for controlling a position of droplet release of the droplet generator. The reservoir is held on the steering system for storing tin. The nozzle is connected with the reservoir for generating tin droplets, wherein the nozzle comprises at least a first zone, a second zone and a third zone connected in sequence. The first heater surrounds a peripheral surface of the nozzle in the first zone. The second heater surrounds a peripheral surface of the nozzle in the second zone. The third heater surrounds a peripheral surface of the nozzle in the third zone, wherein the heating of the first heater, the second heater and the third heater are separately controlled.
Abstract: A lithography apparatus includes an extreme ultraviolet (EUV) scanner, an EUV source coupled to the EUV scanner, a quartz crystal microbalance and a feedback controller. The quartz crystal microbalance is disposed on an internal surface of at least one of the EUV source and the EUV scanner. The feedback controller is coupled to the quartz crystal microbalance and one or more of a radiation source, a droplet generator, and optical guide elements controlling the trajectory of the radiation source associated with the EUV source.
Abstract: A device includes a laser source, an amplifier, an optical sensor and a spectrometer. The laser source is configured to produce a seed laser beam. The amplifier includes gain medium and a discharging unit. The discharging unit is configured to pump the gain medium for amplifying power of the seed laser beam. The optical sensor is coupled to the amplifier and configured for sensing an optical emission generated in the amplifier while the gain medium is discharging. The spectrometer is coupled with the optical sensor and configured to measure a spectrum of the optical emission.
Abstract: An extreme ultraviolet (EUV) lithography method includes causing a first metallic droplet to move along a shroud and through an aperture of the shroud at a first velocity, and adjusting an open area of the aperture of the shroud. After adjusting the open area of the aperture of the shroud, a second metallic droplet is caused to move along the shroud and through the aperture of the shroud at a second velocity, in which the second velocity is different from the first velocity.
Abstract: An apparatus for generating extreme ultraviolet (EUV) radiation comprises a droplet generator, an excitation laser source, an energy detector, and a feedback controller. The droplet generator is configured to generate target droplets. The excitation laser is configured to generate a pre-pulse and a main pulse to convert the target droplets to plasma by heating. The energy detector is configured to measure a variation in EUV energy generated when the target droplets are converted to plasma. The feedback controller is configured to adjust a time delay between a subsequent pre-pulse and main pulse generated by the excitation laser based on the variation in EUV energy generated by a given main pulse.
Abstract: An EUV lithographic apparatus includes a wafer stage and a particle removing assembly for cleaning a wafer for an extreme ultraviolet (EUV) lithographic apparatus. The wafer stage includes a measurement side and an exposure side. The particle removing assembly includes particle removing electrodes, an exhaust device and turbomolecular pumps. The particle removing electrodes is configured to direct debris from the chamber by suppressing turbulence such that the debris can be exhausted from the wafer stage to the outside of the processing apparatus. In some embodiments, turbomolecular pumps are turned off in the measurement side of the wafer stage so that an exhaust flow can be guided to an exposure side of the wafer stage. In some embodiments, the speed of voltage rise to the electrodes of the wafer chuck is adjusted.
Abstract: A method for collecting information in image-error compensation is provided. The method includes providing a reticle having a first image structure and a second image structure; moving a light shading member to control a first exposure field; projecting a light over the first exposure field; recording an image of the first image structure after the light is projected; moving the light shading member to control a second exposure field; projecting the light over the second exposure field; and recording an image of the second image structure after the light is projected.
Abstract: A droplet generator assembly includes a storage tank, a refill system, a droplet generator, and a temperature control system. The storage tank is configured to store a target material. The refill system is connected to the storage tank. The droplet generator includes a reservoir and a nozzle connected to the reservoir, in which the droplet generator is connected to the refill system, and the refill system is configured to deliver the target material to the reservoir. The temperature control system is adjacent to the refill system or the reservoir.
Abstract: An extreme ultraviolet radiation source apparatus includes a chamber including at least a droplet generator, a nozzle of the droplet generator, and a dry ice blasting assembly. The droplet generator includes a reservoir for a molten metal, and the nozzle has a first end connected to the reservoir and a second opposing end where molten metal droplets emerge from the nozzle. The dry ice blasting assembly includes a blasting nozzle, a blasting air inlet and a blaster carbon dioxide (CO2) inlet. The blasting nozzle is disposed inside the chamber. The blasting nozzle is arranged to direct a pressurized air stream and dry ice particles at the nozzle of the droplet generator.
Abstract: A layout modification method for fabricating a semiconductor device is provided. The layout modification method includes calculating uniformity of critical dimensions of first and second portions in a patterned layer by using a layout for an exposure manufacturing process to produce the semiconductor device. A width of the first and second portions equals a penumbra size of the exposure manufacturing process. The penumbra size is utilized to indicate which area of the patterned layer is affected by light leakage exposure from another exposure manufacturing process. The layout modification method further includes compensating non-uniformity of the first and second portions of the patterned layer according to the uniformity of critical dimensions to generate a modified layout. The first portion is divided into a plurality of first sub-portions. The second portion is divided into a plurality of second sub-portions. Each second sub-portion is surrounded by two of the first sub-portions.
Abstract: A method includes irradiating a target droplet in an extreme ultraviolet light source of an extreme ultraviolet lithography tool with light from a droplet illumination module. Light reflected and/or scattered by the target droplet is detected. Particle image velocimetry is performed to monitor one or more flow parameters inside the extreme ultraviolet light source.
June 7, 2021
September 23, 2021
En Hao LAI, Chi YANG, Shang-Chieh CHIEN, Li-Jui CHEN, Po-Chung CHENG
Abstract: A method includes ejecting a metal droplet from a reservoir of a first droplet generator assembled to a vessel; emitting an excitation laser from a laser source to the metal droplet to generate extreme ultraviolet (EUV) radiation; turning off the first droplet generator; cooling down the first droplet generator to a temperature not lower than about 150° C.; dismantling the first droplet generator from the vessel at the temperature not lower than about 150° C.; and assembling a second droplet generator to the vessel.
Abstract: A droplet catcher system of an EUV lithography apparatus is provided. The droplet catcher system includes a catcher body, a heat transfer part, a heat exchanger, and a controller. The catcher body has an outer surface. The heat transfer part is directly attached to the outer surface of the catcher body. The heat exchanger is thermally coupled to the heat transfer part. The controller is electrically coupled to the heat exchanger.
Abstract: A reticle holding tool is provided. The reticle holding tool includes a housing, a reticle chuck, and a gas delivery assembly. The housing includes an opening, a top housing member, and a lateral housing member extending from the top housing member and terminating at a lower edge which is located on a predetermined plane. The reticle chuck is positioned in the housing and has an effective surface configured to secure a reticle. The effective surface is located between the predetermined plane and the top housing member. The reticle chuck is movable between two boundary lines that are perpendicular to the effective surface. A width of the opening is greater than a distance between the two boundary lines. The gas delivery assembly is positioned within the housing and configured to supply gas into the housing.
Abstract: A target droplet source for an extreme ultraviolet (EUV) source includes a droplet generator configured to generate target droplets of a given material. The droplet generator includes a nozzle configured to supply the target droplets in a space enclosed by a chamber. The target droplet source further includes a sleeve disposed in the chamber distal to the nozzle. The sleeve is configured to provide a path for the target droplets in the chamber.
Abstract: A method of inspecting a reticle includes obtaining a first image of a surface of the reticle at a first height by scanning the reticle surface with a light source at the first height of the reticle surface relative to a reference surface height of the reticle surface and obtaining a second image of the reticle surface at a second height by scanning the reticle surface with the light source at the second height of the reticle surface relative to the reference surface height of the reticle surface. The second height is different from the first height. The first and the second images are then combined to obtain a surface profile image of the reticle.