Abstract: An extreme ultraviolet light system includes a steering system that steers and focuses an amplified light beam traveling along a propagation direction to a focal plane near a target location within an extreme ultraviolet light chamber, a detection system including at least one detector positioned to detect an image of a laser beam reflected from at least a portion of a target material within the chamber, a wavefront modification system in the path of the reflected laser beam and between the target location and the detection system, and a controller. The wavefront modification system is configured to modify the wavefront of the reflected laser beam as a function of a target focal plane position along the propagation direction. The controller includes logic for adjusting a location of the focal plane of the amplified light beam relative to the target material based on the detected image of the reflected laser beam.

Abstract: An extreme ultraviolet light system includes a target material delivery system configured to produce a target material; and a beam delivery system that is configured to receive an amplified light beam emitted from a drive laser system and to direct the amplified light beam toward a target location that receives the target material. The beam delivery system includes a final focus assembly that focuses the amplified light beam at a focal location to enable interaction between the amplified light beam and the target material to cause the target material to be converted into a plasma that emits extreme ultraviolet light. The final focus assembly includes at least one transmissive optical element having at least one curved surface through which the amplified light beam travels; and at least one reflective optical element having at least one curved surface on which the amplified light beam is reflected.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Extreme ultraviolet light (EUV) is produced in a laser-produced plasma (LPP) EUV light source when laser light strikes a target. Measuring reflected light from the target by a Return Beam Diagnostics (RBD) module provides data on EUV production, including but not limited to target position, target focus, target shape, and target profile. In a RBD module, a controller sequences an optical switch to direct the reflected light between a blocking element and a sensing device, providing greater flexibility in measuring the reflected light during different aspects of the EUV generation process, such as different power levels and duty cycles of the laser light striking the target.

Abstract: An extreme ultraviolet light system includes a target material delivery system configured to produce a target material; and a beam delivery system that is configured to receive an amplified light beam emitted from a drive laser system and to direct the amplified light beam toward a target location that receives the target material. The beam delivery system includes a final focus assembly that focuses the amplified light beam at a focal location to enable interaction between the amplified light beam and the target material to cause the target material to be converted into a plasma that emits extreme ultraviolet light. The final focus assembly includes at least one transmissive optical element having at least one curved surface through which the amplified light beam travels; and at least one reflective optical element having at least one curved surface on which the amplified light beam is reflected.

Abstract: An aspect of the disclosed subject matter includes a method of reducing the laser absorption of a beam reverser prism consisting of at least one of the following: increasing a first distance between a first incident point and a chamfered corner, wherein the first incident point is on a first reflective surface of the prism and the chamfered corner is formed between the first reflective surface and a second reflective surface of the prism, wherein the chamfered corner has a chamfered surface; increasing a second distance between a second incident point and the chamfered corner, wherein the second incident point is on the second reflective surface of the prism; and increasing a reflectivity of the chamfered surface of the chamfered corner of the prism. A method of determining a prime cut for an optical component is also disclosed. A laser including at least one prime cut optical component is also disclosed.

Abstract: Extreme ultraviolet light (EUV) is produced in a laser-produced plasma (LPP) EUV light source when laser light strikes a target. Measuring reflected light from the target by a Return Beam Diagnostics (RBD) module provides data on EUV production, including but not limited to target position, target focus, target shape, and target profile. In a RBD module, a controller sequences an optical switch to direct the reflected light between a blocking element and a sensing device, providing greater flexibility in measuring the reflected light during different aspects of the EUV generation process, such as different power levels and duty cycles of the laser light striking the target.

Abstract: An extreme ultraviolet light system includes a steering system that steers and focuses an amplified light beam traveling along a propagation direction to a focal plane near a target location within an extreme ultraviolet light chamber, a detection system including at least one detector positioned to detect an image of a laser beam reflected from at least a portion of a target material within the chamber, a wavefront modification system in the path of the reflected laser beam and between the target location and the detection system, and a controller. The wavefront modification system is configured to modify the wavefront of the reflected laser beam as a function of a target focal plane position along the propagation direction. The controller includes logic for adjusting a location of the focal plane of the amplified light beam relative to the target material based on the detected image of the reflected laser beam.

Abstract: A dichroic beam splitter module is disclosed for separating a main pulse laser beam from a pre-pulse laser beam each traversing a common beam path. In one embodiment, two dichroic elements are physically aligned along the beam path and are configured to pass the pre-pulse, a laser light having a first wavelength, to target material located near an irradiation site yet reflect the main pulse, a laser light having a second wavelength. The reflected main pulse is then further reflected by two reflective elements or mirrors from the first dichroic element to the second dichroic element and then on to the irradiation site. In alternative embodiments, the first mirror is deformable to alter beam characteristics of the reflected main pulse beam and the second mirror is adjustable to align the main pulse beam to the irradiation site.

Abstract: An extreme ultraviolet light system includes a steering system that steers and focuses an amplified light beam traveling along a propagation direction to a focal plane near a target location within an extreme ultraviolet light chamber, a detection system including at least one detector positioned to detect an image of a laser beam reflected from at least a portion of a target material within the chamber, a wavefront modification system in the path of the reflected laser beam and between the target location and the detection system, and a controller. The wavefront modification system is configured to modify the wavefront of the reflected laser beam as a function of a target focal plane position along the propagation direction. The controller includes logic for adjusting a location of the focal plane of the amplified light beam relative to the target material based on the detected image of the reflected laser beam.

Abstract: A dichroic beam splitter module is disclosed for separating a main pulse laser beam from a pre-pulse laser beam each traversing a common beam path. In one embodiment, two dichroic elements are physically aligned along the beam path and are configured to pass the pre-pulse, a laser light having a first wavelength, to target material located near an irradiation site yet reflect the main pulse, a laser light having a second wavelength. The reflected main pulse is then further reflected by two reflective elements or mirrors from the first dichroic element to the second dichroic element and then on to the irradiation site. In alternative embodiments, the first mirror is deformable to alter beam characteristics of the reflected main pulse beam and the second mirror is adjustable to align the main pulse beam to the irradiation site.

Abstract: A line narrowed gas discharge laser system and method of operating same is disclosed which may comprise a dispersive center wavelength selective element; a beam expander comprising a plurality of refractive elements; a refractive element positioning mechanism positioning at least one of the refractive elements to modify an angle of incidence of a laser light beam on the dispersive center wavelength selection element; each of the dispersive center wavelength selection element and the beam expander being aligned with each other and with a housing containing at least the dispersive center wavelength selection element; a housing positioning mechanism positioning the housing with respect to an optical axis of the gas discharge laser system. The dispersive element may comprise a grating and the beam expander may comprise a plurality of prisms. The housing may contain the dispersive center wavelength selective element and the beam expander. The housing positioning element may comprise a position locking mechanism.

Abstract: An aspect of the disclosed subject matter includes a method of reducing the laser absorption of a beam reverser prism consisting of at least one of the following: increasing a first distance between a first incident point and a chamfered corner, wherein the first incident point is on a first reflective surface of the prism and the chamfered corner is formed between the first reflective surface and a second reflective surface of the prism, wherein the chamfered corner has a chamfered surface; increasing a second distance between a second incident point and the chamfered corner, wherein the second incident point is on the second reflective surface of the prism; and increasing a reflectivity of the chamfered surface of the chamfered corner of the prism. A method of determining a prime cut for an optical component is also disclosed. A laser including at least one prime cut optical component is also disclosed.

Abstract: An aspect of the disclosed subject matter includes a method of reducing the laser absorption of a beam reverser prism consisting of at least one of the following: increasing a first distance between a first incident point and a chamfered corner, wherein the first incident point is on a first reflective surface of the prism and the chamfered corner is formed between the first reflective surface and a second reflective surface of the prism, wherein the chamfered corner has a chamfered surface; increasing a second distance between a second incident point and the chamfered corner, wherein the second incident point is on the second reflective surface of the prism; and increasing a reflectivity of the chamfered surface of the chamfered corner of the prism. A method of determining a prime cut for an optical component is also disclosed. A laser including at least one prime cut optical component is also disclosed.

Abstract: An extreme ultraviolet light system includes a drive laser system that produces an amplified light beam; a target material delivery system configured to produce a target material at a target location; an extreme ultraviolet light vacuum chamber defining an interior vacuum space that houses an extreme ultraviolet light collector and the target location; and a beam delivery system that is configured to receive the amplified light beam emitted from the drive laser system and to direct the amplified light beam toward the target location. The beam delivery system includes a beam expansion system that expands a size of the amplified light beam and a focusing element that is configured and arranged to focus the amplified light beam at the target location.

Abstract: A method and apparatus may comprise a line narrowed pulsed excimer or molecular fluorine gas discharge laser system which may comprise a seed laser oscillator producing an output comprising a laser output light beam of pulses which may comprise a first gas discharge excimer or molecular fluorine laser chamber; a line narrowing module within a first oscillator cavity; a laser amplification stage containing an amplifying gain medium in a second gas discharge excimer or molecular fluorine laser chamber receiving the output of the seed laser oscillator and amplifying the output of the seed laser oscillator to form a laser system output comprising a laser output light beam of pulses, which may comprise a ring power amplification stage.

Abstract: An apparatus is disclosed which may comprise a grating receiving light, a first prism moveable to coarsely select an angle of incidence of the light on the grating, and a second prism moveable to finely select an angle of incidence of the light on the grating. In one application, the apparatus may be used as a line narrowing module for a laser light source.