Abstract: An extreme ultraviolet (EUV) light source includes a vacuum chamber with a rotating target assembly therein. The rotating target assembly has an annular groove with a distal wall relative to an axis of rotation. The distal wall includes a porous region. The rotating target assembly is rotated to form a target by centrifugal force with a layer of molten metal on a distal wall of an annular groove in the rotating target assembly.

Abstract: A method for producing a protective buffer flow in an EUV light source and an EUV mask inspection apparatus are provided. The method includes directing light along a light path from the EUV light source toward a collector. A first buffer gas from a buffer gas injector is injected through a plurality of through holes in the collector. The first buffer gas is directed away from a surface of the collector. A second buffer gas is injected from a ring manifold arranged peripherally to the collector and arranged a first distance toward the light path in relation to the collector. The second buffer gas is directed away from the surface of the collector. The first distance corresponds to a distance from the collector where the first buffer gas merges into a single flow.

Abstract: A method for producing a protective buffer flow in an EUV light source and an EUV mask inspection apparatus are provided. The method includes directing light along a light path from the EUV light source toward a collector. A first buffer gas from a buffer gas injector is injected through a plurality of through holes in the collector. The first buffer gas is directed away from a surface of the collector. A second buffer gas is injected from a ring manifold arranged peripherally to the collector and arranged a first distance toward the light path in relation to the collector. The second buffer gas is directed away from the surface of the collector. The first distance corresponds to a distance from the collector where the first buffer gas merges into a single flow.

Abstract: The present disclosure is directed to a device having a nozzle for dispensing a liquid target material; one or more intermediary chamber(s), each intermediary chamber positioned to receive target material and formed with an exit aperture to output target material for downstream irradiation in a laser produced plasma (LPP) chamber. In some disclosed embodiments, control systems are included for controlling one or more of gas temperature, gas pressure and gas composition in one, some or all of a device's intermediary chamber(s). In one embodiment, an intermediary chamber having an adjustable length is disclosed.

Abstract: Methods and systems for positioning a specimen and characterizing an x-ray beam incident onto the specimen in a Transmission, Small-Angle X-ray Scatterometry (T-SAXS) metrology system are described herein. A specimen positioning system locates a wafer vertically and actively positions the wafer in six degrees of freedom with respect to the x-ray illumination beam without attenuating the transmitted radiation. In some embodiments, a cylindrically shaped occlusion element is scanned across the illumination beam while the detected intensity of the transmitted flux is measured to precisely locate the beam center. In some other embodiments, a periodic calibration target is employed to precisely locate the beam center. The periodic calibration target includes one or more spatially defined zones having different periodic structures that diffract X-ray illumination light into distinct, measurable diffraction patterns.

Abstract: The present disclosure is directed to a device having a nozzle for dispensing a liquid target material; one or more intermediary chamber(s), each intermediary chamber positioned to receive target material and formed with an exit aperture to output target material for downstream irradiation in a laser produced plasma (LPP) chamber. In some disclosed embodiments, control systems are included for controlling one or more of gas temperature, gas pressure and gas composition in one, some or all of a device's intermediary chamber(s). In one embodiment, an intermediary chamber having an adjustable length is disclosed.

Abstract: Methods and systems for x-ray based semiconductor metrology utilizing a broadband, soft X-ray illumination source are described herein. A laser produced plasma (LPP) light source generates high brightness, broadband, soft x-ray illumination. The LPP light source directs a highly focused, short duration laser source to a non-metallic droplet target in a liquid or solid state. In one example, a droplet generator dispenses a sequence of nominally 50 micron droplets of feed material at a rate between 50 and 400 kilohertz. In one aspect, the duration of each pulse of excitation light is less than one nanosecond. In some embodiments, the duration of each pulse of excitation light is less than 0.5 nanoseconds. In some embodiments, the LPP light source includes a gas separation system that separates unspent feed material from other gases in the plasma chamber and provides the separated feed material back to the droplet generator.

Abstract: The present disclosure is directed to a device having a nozzle for dispensing a liquid target material; one or more intermediary chamber(s), each intermediary chamber positioned to receive target material and formed with an exit aperture to output target material for downstream irradiation in a laser produced plasma (LPP) chamber. In some disclosed embodiments, control systems are included for controlling one or more of gas temperature, gas pressure and gas composition in one, some or all of a device's intermediary chamber(s). In one embodiment, an intermediary chamber having an adjustable length is disclosed.

Abstract: Multilayer targets enabling fast and accurate, absolute calibration and alignment of X-ray based measurement systems are described herein. The multilayer calibration targets have very high diffraction efficiency and are manufactured using fast, low cost production techniques. Each target includes a multilayer structure built up with pairs of X-ray transparent and X-ray absorbing materials. The layers of the multilayer target structure is oriented parallel to an incident X-ray beam. Measured diffraction patterns indicate misalignment in position and orientation between the incident X-Ray beam and the multilayer target. In another aspect, a composite multilayer target includes at least two multilayer structures arranged adjacent one another along a direction aligned with the incident X-ray beam, adjacent one another along a direction perpendicular to the incident X-ray beam, or a combination thereof. In some embodiments, the multilayer structures are spatially separated from one another by a gap distance.

Abstract: Multilayer targets enabling fast and accurate, absolute calibration and alignment of X-ray based measurement systems are described herein. The multilayer calibration targets have very high diffraction efficiency and are manufactured using fast, low cost production techniques. Each target includes a multilayer structure built up with pairs of X-ray transparent and X-ray absorbing materials. The layers of the multilayer target structure is oriented parallel to an incident X-ray beam. Measured diffraction patterns indicate misalignment in position and orientation between the incident X-Ray beam and the multilayer target. In another aspect, a composite multilayer target includes at least two multilayer structures arranged adjacent one another along a direction aligned with the incident X-ray beam, adjacent one another along a direction perpendicular to the incident X-ray beam, or a combination thereof. In some embodiments, the multilayer structures are spatially separated from one another by a gap distance.

Abstract: Methods and systems for reducing the effect of finite source size on illumination beam spot size for Transmission, Small-Angle X-ray Scatterometry (T-SAXS) measurements are described herein. A beam shaping slit having a slender profile is located in close proximity to the specimen under measurement and does not interfere with wafer stage components over the full range of angles of beam incidence. In one embodiment, four independently actuated beam shaping slits are employed to effectively block a portion of an incoming x-ray beam and generate an output beam having a box shaped illumination cross-section. In one aspect, each of the beam shaping slits is located at a different distance from the specimen in a direction aligned with the beam axis. In another aspect, the beam shaping slits are configured to rotate about the beam axis in coordination with the orientation of the specimen.

Abstract: Methods and systems for x-ray based semiconductor metrology utilizing a broadband, soft X-ray illumination source are described herein. A laser produced plasma (LPP) light source generates high brightness, broadband, soft x-ray illumination. The LPP light source directs a highly focused, short duration laser source to a non-metallic droplet target in a liquid or solid state. In one example, a droplet generator dispenses a sequence of nominally 50 micron droplets of feed material at a rate between 50 and 400 kilohertz. In one aspect, the duration of each pulse of excitation light is less than one nanosecond. In some embodiments, the duration of each pulse of excitation light is less than 0.5 nanoseconds. In some embodiments, the LPP light source includes a gas separation system that separates unspent feed material from other gases in the plasma chamber and provides the separated feed material back to the droplet generator.

Abstract: Methods and systems for positioning a specimen and characterizing an x-ray beam incident onto the specimen in a Transmission, Small-Angle X-ray Scatterometry (T-SAXS) metrology system are described herein. A specimen positioning system locates a wafer vertically and actively positions the wafer in six degrees of freedom with respect to the x-ray illumination beam without attenuating the transmitted radiation. In some embodiments, a cylindrically shaped occlusion element is scanned across the illumination beam while the detected intensity of the transmitted flux is measured to precisely locate the beam center. In some other embodiments, a periodic calibration target is employed to precisely locate the beam center. The periodic calibration target includes one or more spatially defined zones having different periodic structures that diffract X-ray illumination light into distinct, measurable diffraction patterns.

Abstract: The present disclosure is directed to plasma-based light sources. Systems and methods are described for protecting components of the light source from plasma generated debris which can include target material gas, atomic vapor, high energy ions, neutrals, micro-particles, and contaminants. Particular embodiments include arrangements for reducing the adverse effects of plasma generated ions and neutrals on light source components while simultaneously reducing in-band light attenuation due to target material gas and vapor.

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: Methods and systems for reducing the effect of finite source size on illumination beam spot size for Transmission, Small-Angle X-ray Scatterometry (T-SAXS) measurements are described herein. A beam shaping slit having a slender profile is located in close proximity to the specimen under measurement and does not interfere with wafer stage components over the full range of angles of beam incidence. In one embodiment, four independently actuated beam shaping slits are employed to effectively block a portion of an incoming x-ray beam and generate an output beam having a box shaped illumination cross-section. In one aspect, each of the beam shaping slits is located at a different distance from the specimen in a direction aligned with the beam axis. In another aspect, the beam shaping slits are configured to rotate about the beam axis in coordination with the orientation of the specimen.

Abstract: The present disclosure is directed to a device having a nozzle for dispensing a liquid target material; one or more intermediary chamber(s), each intermediary chamber positioned to receive target material and formed with an exit aperture to output target material for downstream irradiation in a laser produced plasma (LPP) chamber. In some disclosed embodiments, control systems are included for controlling one or more of gas temperature, gas pressure and gas composition in one, some or all of a device's intermediary chamber(s). In one embodiment, an intermediary chamber having an adjustable length is disclosed.

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: The present disclosure is directed to plasma-based light sources. Systems and methods are described for protecting components of the light source from plasma generated debris which can include target material gas, atomic vapor, high energy ions, neutrals, micro-particles, and contaminants. Particular embodiments include arrangements for reducing the adverse effects of plasma generated ions and neutrals on light source components while simultaneously reducing in-band light attenuation due to target material gas and vapor.

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.