Abstract: A method and apparatus for creating and utilizing dual laser curtains from a single laser source in a laser produced plasma (LPP) extreme ultraviolet (EUV) light system is disclosed. A polarizing beam splitter creates two beams of orthogonal polarization from a single laser, and the beams are used to generate two laser curtains. Sensors detect flashes from droplets of target material as they pass through the curtains. One sensor may detect the position of the droplets relative to a desired trajectory to the irradiation site so that the orientation of a droplet generator may be adjusted to direct subsequent droplets to the irradiation site, as in the prior art. A second sensor may detect each droplet as it passes through a curtain to determine when a source laser should generate a pulse so that the pulse will arrive at the irradiation site at the same time as the droplet, so that a signal may be sent to the source laser to fire at the correct time.

Abstract: A method and apparatus for improved control of the trajectory and timing of droplets of target material in a laser produced plasma (LPP) extreme ultraviolet (EUV) light system is disclosed. A droplet illumination module generates two laser curtains for detecting the droplets. The first curtain is used for detecting the position of the droplets relative to a desired trajectory to the irradiation site so that the position of a droplet generator may be adjusted to direct the droplets to the irradiation site, as in the prior art. A droplet detection module detects each droplet as it passes through the second curtain, determines when the source laser should generate a pulse so that the pulse arrives at the irradiation site at the same time as the droplet, and sends a signal to the source laser to fire at the correct time.

Abstract: A method and apparatus for improved control of the trajectory and timing of droplets of target material in a laser produced plasma (LPP) extreme ultraviolet (EUV) light system is disclosed. A droplet illumination module generates two laser curtains for detecting the droplets. The first curtain is used for detecting the position of the droplets relative to a desired trajectory to the irradiation site so that the position of a droplet generator may be adjusted to direct the droplets to the irradiation site, as in the prior art. A droplet detection module detects each droplet as it passes through the second curtain, determines when the source laser should generate a pulse so that the pulse arrives at the irradiation site at the same time as the droplet, and sends a signal to the source laser to fire at the correct time.

Abstract: A method and apparatus for creating and utilizing dual laser curtains from a single laser source in a laser produced plasma (LPP) extreme ultraviolet (EUV) light system is disclosed. A polarizing beam splitter creates two beams of orthogonal polarization from a single laser, and the beams are used to generate two laser curtains. Sensors detect flashes from droplets of target material as they pass through the curtains. One sensor may detect the position of the droplets relative to a desired trajectory to the irradiation site so that the orientation of a droplet generator may be adjusted to direct subsequent droplets to the irradiation site, as in the prior art. A second sensor may detect each droplet as it passes through a curtain to determine when a source laser should generate a pulse so that the pulse will arrive at the irradiation site at the same time as the droplet, so that a signal may be sent to the source laser to fire at the correct time.

Abstract: An apparatus and method for detecting extreme ultraviolet (EUV) radiation is disclosed. The apparatus includes a detector having a top surface, a layer of scintillation material on the top surface of the detector, a layer of spacer material on the layer of scintillation material, and a spectral purity filter layer on the layer of spacer material. The method includes directing the EUV radiation through the spectral purity filter layer and through the spacer material layer. The spacer material layer may be disposed between the spectral purity filter layer and a layer of scintillation material. The method further includes detecting scintillation radiation emitted by the scintillation material using the detector.

Abstract: A method and apparatus for improved control of the trajectory and timing of droplets of target material in a laser produced plasma (LPP) extreme ultraviolet (EUV) light system is disclosed. A droplet illumination module generates a laser curtain, and sensors detect the droplets as they pass through the curtain. One sensor in combination with a controller detects the position of the droplets relative to a desired trajectory to the irradiation site so that a signal can be sent to an actuator of a droplet generator to adjust orientation of the droplet generator and direct subsequent droplets to the irradiation site, as in the prior art. A second sensor, or droplet detection module, also detects each droplet as it passes through the curtain, and in combination with a controller determines when the source laser should generate a pulse so that the pulse will arrive at the irradiation site at the same time as the droplet, and sends a signal to the source laser to fire at the correct time.

Abstract: A detector including a layer of scintillation material, a layer of spacer material on the scintillation material, and a spectral purity filter layer on the spacer material.

Abstract: A method and apparatus are provided for measuring the apodization of projection optics for use in a lithographic apparatus, the projection optics having an object plane where, in use, a reticle is placed, a pupil plane, and an image plane where, in use, a wafer is placed. The method includes placing one or more Appropriate apertures in said object plane for creating a substantially uniform light distribution, illuminating the or each aperture and measuring the intensity distribution at a plane which is conjugate to the pupil plane in order to calculate the apodization of the projection optics.