Abstract: An apparatus for generating extreme ultra-violet (EUV) light, including a drive laser arranged to produce a laser pulse, a vacuum chamber, a set of focusing optics arranged to focus the laser pulse produced by the drive laser onto a target spot within the vacuum chamber, a target material generator arranged to deliver a series of droplets of a target material to the target spot by modulating a flow velocity of a supply of the target material through a nozzle tip and thereby inducing a formation process of the series of droplets which series of droplets from the nozzle tip are expelled through a triple point chamber, and a set of collector optics arranged to focus a quantity of EUV light generated when a droplet of the series of drople of the target material is exposed to the laser pulse at the target spot onto an intermediate focus spot.

Abstract: An EUV light source includes a rotatable, cylindrically-symmetric element having a surface coated with a plasma-forming target material, a drive laser source configured to generate one or more laser pulses sufficient to generate EUV light via formation of a plasma by excitation of the plasma-forming target material, a set of focusing optics configured to focus the one or more laser pulses onto the surface of the rotatable, cylindrically-symmetric element, a set of collection optics configured to receive EUV light emanated from the generated plasma and further configured to direct the illumination to an intermediate focal point, and a gas management system including a gas supply subsystem configured to supply plasma-forming target material to the surface of the rotatable, cylindrically-symmetric element.

Abstract: A system for producing an exclusionary buffer gas flow in an EUV light source, comprising a vacuum chamber, a light path, a plasma generation region, at least one shield, at least one through-bore arranged in the at least one shield, at least one buffer gas injector arranged within the at least one through-bore to inject a buffer gas into the light path substantially towards the plasma generation region to prevent a flow of a target material into the light path, and a vacuum pump arranged to remove the buffer gas and the target material from the vacuum chamber.

Abstract: The present disclosure is directed to a system for protecting a reflective optic and/or any other surface in a plasma-based illumination system from debris by actively flowing gas against the debris flow direction. According to various embodiments, a vacuum chamber is configured to contain a target material, wherein a laser or discharge produced plasma is generated in response to an excitation of the target material. One or more outlets within the chamber are configured to receive gas flowing from a fluidically coupled gas source and further configured to actively flow the gas towards a source of debris and away from the reflective optic or any other protected surface at a controlled flow rate.

Abstract: An apparatus for generating extreme ultra-violet (EUV) light for use in a lithography inspection tool, comprising a drive laser arranged to produce a laser pulse, a vacuum chamber, a set of focusing optics arranged to focus the laser pulse produced by the drive laser onto a target spot within the vacuum chamber with a beam target diameter of less than 100 ?m, a target material generator arranged to deliver an amount of a target material to the target spot within the vacuum chamber, and a set of collector optics arranged to focus a quantity of EUV light generated when the amount of the target material is exposed to the laser pulse at the target spot onto an intermediate focus spot.

Abstract: A device is disclosed which may comprise a system generating a plasma at a plasma site, the plasma producing EUV radiation and ions exiting the plasma. The device may also include an optic, e.g., a multi-layer mirror, distanced from the site by a distance, d, and a flowing gas disposed between the plasma and optic, the gas establishing a gas pressure sufficient to operate over the distance, d, to reduce ion energy below a pre-selected value before the ions reach the optic. In one embodiment, the gas may comprise hydrogen and in a particular embodiment, the gas may comprise greater than 50 percent hydrogen by volume.

Abstract: An apparatus and method is disclosed which may comprise a laser produced plasma EUV system which may comprise a drive laser producing a drive laser beam; a drive laser beam first path having a first axis; a drive laser redirecting mechanism transferring the drive laser beam from the first path to a second path, the second path having a second axis; an EUV collector optical element having a centrally located aperture; and a focusing mirror in the second path and positioned within the aperture and focusing the drive laser beam onto a plasma initiation site located along the second axis. The apparatus and method may comprise the drive laser beam is produced by a drive laser having a wavelength such that focusing on an EUV target droplet of less than about 100 ?m at an effective plasma producing energy if not practical in the constraints of the geometries involved utilizing a focusing lens. The drive laser may comprise a CO2 laser. The drive laser redirecting mechanism may comprise a mirror.

Abstract: An EUV light generation system and method is disclosed that may comprise a droplet generator producing plasma source material target droplets traveling toward the vicinity of a plasma source material target irradiation site; a drive laser; a drive laser focusing optical element having a first range of operating center wavelengths; a droplet detection radiation source having a second range of operating center wavelengths; a drive laser steering element comprising a material that is highly reflective within at least some part of the first range of wavelengths and highly transmissive within at least some part of the second range of center wavelengths; a droplet detection radiation aiming mechanism directing the droplet detection radiation through the drive laser steering element and the lens to focus at a selected droplet detection position intermediate the droplet generator and the irradiation site.

Abstract: A laser produced plasma (“LPP”) extreme ultraviolet (“EUV”) light source and method of operating same is disclosed which may comprise an EUV plasma production chamber having a chamber wall; a drive laser entrance window in the chamber wall; a drive laser entrance enclosure intermediate the entrance window and a plasma initiation site within the chamber and comprising an entrance enclosure distal end opening; at least one aperture plate intermediate the distal opening and the entrance window comprising at least one drive laser passage aperture. The at least one aperture plate may comprise at least two aperture plates comprising a first aperture plate and a second aperture plate defining an aperture plate interim space. The at least one drive laser aperture passage may comprise at least two drive laser aperture passages.

Abstract: A method for generating EUV light is disclosed which may include the acts/steps of providing a source material; generating a plurality of source material droplets; simultaneously irradiating a plurality of source material droplets with a first light pulse to create irradiated source material; and thereafter exposing the irradiated source material to a second light pulse to generate EUV light, e.g. by generating a plasma of the source material. In another aspect, an EUV light source may include a droplet generator delivering a plurality of source material droplets to a target volume; a source of a first light pulse for simultaneously irradiating a plurality of droplets in the target volume to produce an irradiated source material; and a source of a second light pulse for exposing the irradiated source material to generate EUV light. The droplet generator may comprise a non-modulating droplet generator and may comprise a multi-orifice nozzle.

Abstract: An EUV light source is disclosed which may comprise at least one optical element having a surface, such as a multi-layer collector mirror; a laser source generating a laser beam; and a source material irradiated by the laser beam to form a plasma and emit EUV light. In one aspect, the source material may consist essentially of a tin compound and may generate tin debris by plasma formation which deposits on the optical element and, in addition, the tin compound may include an element that is effective in etching deposited tin from the optical element surface. Tin compounds may include SnBr4, SnBr2 and SnH4. In another aspect, an EUV light source may comprise a molten source material irradiated by a laser beam to form a plasma and emit EUV light, the source material comprising tin and at least one other metal, for example tin with Gallium and/or Indium.

Abstract: An EUV target delivery system and method are disclosed which may comprise: a target material purification system connected to deliver liquid target material comprising: a first container and a second container in fluid contact with the target material reservoir; a filter intermediate the first chamber and the second chamber; a liquid target material agitation mechanism, or at least one purification chamber containing the target material in a form reactive with impurities contained in the inert gas reacting with such impurities and removing from the inert gas the impurities, or providing an evaporation chamber in fluid communication with an impurity chamber and with a target droplet mechanism liquid target material reservoir and containing liquid source material; heating the liquid source material to a first temperature sufficient to evaporate a first set of contaminants; heating the liquid source material to a second temperature sufficient to evaporate lithium.

Abstract: An apparatus and method is disclosed which may comprise a laser produced plasma EUV system which may comprise a drive laser producing a drive laser beam; a drive laser beam first path having a first axis; a drive laser redirecting mechanism transferring the drive laser beam from the first path to a second path, the second path having a second axis; an EUV collector optical element having a centrally located aperture; and a focusing mirror in the second path and positioned within the aperture and focusing the drive laser beam onto a plasma initiation site located along the second axis. The apparatus and method may comprise the drive laser beam is produced by a drive laser having a wavelength such that focusing on an EUV target droplet of less than about 100 ?m at an effective plasma producing energy if not practical in the constraints of the geometries involved utilizing a focusing lens. The drive laser may comprise a CO2 laser. The drive laser redirecting mechanism may comprise a mirror.

Abstract: Systems and methods are disclosed for protecting an EUV light source plasma production chamber optical element surface from debris generated by plasma formation. In one aspect of an embodiment of the present invention, a shield is disclosed which comprises at least one hollow tube positioned between the optical element and a plasma formation site. The tube is oriented to capture debris while allowing light to pass through the tube's lumen via reflection at relatively small angles of grazing incidence. In another aspect of an embodiment of the present invention, a shield is disclosed which is heated to a temperature sufficient to remove one or more species of debris material that has deposited on the shield. In yet another aspect of an embodiment of the present invention, a system is disclosed which a shield is moved from a light source plasma chamber to a cleaning chamber where the shield is cleaned.

Abstract: An EUV plasma formation target delivery system and method is disclosed which may comprise: a target droplet formation mechanism comprising a magneto-restrictive or electro-restrictive material, a liquid plasma source material passageway terminating in an output orifice; a charging mechanism applying charge to a droplet forming jet stream or to individual droplets exiting the passageway along a selected path; a droplet deflector intermediate the output orifice and a plasma initiation site periodically deflecting droplets from the selected path, a liquid target material delivery mechanism comprising a liquid target material delivery passage having an input opening and an output orifice; an electromotive disturbing force generating mechanism generating a disturbing force within the liquid target material, a liquid target delivery droplet formation mechanism having an output orifice; and/or a wetting barrier around the periphery of the output orifice.

Abstract: A source material dispenser for an EUV light source is disclosed that comprises a source material reservoir, e.g. tube, that has a wall and is formed with an orifice. The dispenser may comprise an electro-actuatable element, e.g. PZT material, that is spaced from the wall and operable to deform the wall and modulate a release of source material from the dispenser. A heat source heating a source material in the reservoir may be provided. Also, the dispenser may comprise an insulator reducing the flow of heat from the heat source to the electro-actuatable element. A method of dispensing a source material for an EUV light source is also described. In one method, a first signal may be provided to actuate the electro-actuatable elements to modulate a release of source material and a second signal, different from the first, may be provided to actuate the electro-actuatable elements to unclog the orifice.

Abstract: Systems and methods are disclosed for cleaning a chamber window of an extreme ultraviolet (EUV) light source. The window may have an inside surface facing a chamber interior and an opposed outside surface and the light source may generate debris by plasma formation. For the system, a subsystem may be positioned outside the chamber and may be operable to pass energy through the window to heat debris accumulating on the inside surface of the window. In a first embodiment, the subsystem may place a flowing, heated gas in contact with the outside surface of the window. In another embodiment, electromagnetic radiation may be passed through the window.

Abstract: A dense plasma focus radiation source for generating EUV radiation using Lithium vapor and including a coaxially disposed anode and cathode. The invention includes methods and apparatuses for enhancing the efficiency of EUV radiation production, for protecting, cooling and extending the life of the anode and cathode, for protecting and shielding collecting optics from debris and pressure disturbances in the discharge chamber, and for feeding Lithium into the discharge chamber.

Abstract: A dense plasma focus radiation source for generating EUV radiation using Lithium vapor and including a coaxially disposed anode and cathode. The invention includes methods and apparatuses for enhancing the efficiency of EUV radiation production, for protecting, cooling and extending the life of the anode and cathode, for protecting and shielding collecting optics from debris and pressure disturbances in the discharge chamber, and for feeding Lithium into the discharge chamber.