An EUV collector for an EUV projection exposure apparatus transfers usable EUV light emerging from a source volume into a collection volume separated from the source volume. The source volume has a first source extension along a connection axis between a center of the source volume and a center of the collection volume. The source volume has a second, cross section source extension along a cross section axis perpendicular to the connection axis. The EUV collector images the source volume into the collection volume. The imaging has a first imaging scale along the connection axis and a second imaging scale along the cross section axis. The first imaging scale differs from the second imaging scale by at least 10%.

The present disclosure relates to a photolithography radiation source having an angled primary laser, and an associated method of formation. In some embodiments, the photolithography radiation source has a fuel droplet generator that provides fuel droplets to a source vessel along a first trajectory. A primary laser is configured to generate a primary laser beam along a second trajectory that intersects the first trajectory. The primary laser beam is configured to ignite a plasma from the plurality of fuel droplets that emits radiation. A collector mirror is configured to focus the radiation to an exit aperture of the source vessel. The primary laser beam does not intersect the exit aperture.

A light source includes a light generating chamber and a collector disposed in the light generating chamber. A target material generator configured to propel a quantity of target material toward an irradiation region is disposed in front of a reflective surface of the collector. A plurality of photodetector modules is disposed external to the light generating chamber, with each of the photodetector modules being directed toward the irradiation region. A plurality of tubes is disposed between a corresponding photodetector module and the irradiation region. Each tube has a centerline directed toward the irradiation region, and each tube has a roughened inner surface. The surface roughness of the roughened inner surface is sufficient to cause grazing incidences of light to be eliminated rather than to be reflected off the roughened inner surface. A method of generating light and a method of measuring light energy also are described.

Methods for receiving a high-energy EUV beam and distributing EUV sub-beams to photolithography scanners and the resulting device are disclosed. Embodiments include receiving a high-energy primary EUV beam at a primary splitting optical assembly; splitting the primary EUV beam into primary EUV sub-beams; reflecting the primary EUV sub-beams to beam-splitting optical arrays; splitting the primary EUV sub-beams into secondary EUV sub-beams; reflecting the secondary EUV sub-beams to EUV distribution optical arrays; and distributing simultaneously the secondary EUV sub-beams to scanners.

A reflective EUV optic such as a collector mirror configured as an array of facets that are spaced apart to form respective gaps between adjacent facets. The gaps are used as inlets for gas flow across one of the facets such that flow is introduced parallel to the optic surface. The facets can be made with offsets such that loss of reflective area of the EUV optic can be minimized. The gas facilitates removal of target material from the surface of the facets.

In LPP EUV systems, sinusoidal oscillations or instabilities can occur in the generated EUV energy. This is avoided by detecting when the LPP EUV system is approaching such instability and adjusting the LPP EUV system by moving the laser beam of the LPP EUV system. Detection is done by determining when the generated EUV energy is at or above a primary threshold. Adjusting the LPP EUV system by moving the laser beam is done for a fixed period of time, until a subsequently generated EUV energy is below the primary threshold, until a subsequently generated EUV energy is below the primary threshold for a fixed period of time, or until a subsequently generated EUV energy is at or below a secondary threshold below the primary threshold.

A performance recovery method for an EUV light generation system includes performing a first evaluation step of evaluating performance of EUV light while generating the EUV light at a certain repetition frequency during a first period; performing, when an evaluation result of the first evaluation step is not within a normal range, an adjustment step of adjusting the performance and then the first evaluation step as a check step; performing, when an evaluation result of the check step is within the normal range, a second evaluation step of evaluating performance of the EUV light while generating the EUV light at the repetition frequency during a second period longer than the first period; and terminating processing when the evaluation result of the check step is not within the normal range. An index related to an irradiation position of pulse laser light is evaluated in the first and second evaluation steps.

Methods and apparatuses for a lithography exposure process are described. The method includes irradiating a target droplet with a laser beam to create an extreme ultraviolet (EUV) light. The methods utilized and the apparatuses include two or more collectors for collecting the generated EUV light and reflecting the collected EUV light to a focal point of one of the collectors. In some embodiments, one of the two collectors includes a ring-shaped collector.

An extreme ultraviolet radiation (EUV) source, including: a vessel having an inner vessel wall and an intermediate focus (IF) region; an EUV collector disposed inside the vessel, the EUV collector including a reflective surface configured to reflect EUV radiation toward the intermediate focus region, the reflective surface configured to directionally face the IF region of the vessel; a showerhead disposed along at least a portion of the inner vessel wall, the showerhead including a plurality of nozzles configured to introduce gas into the vessel; and one or more exhausts configured to remove gas introduced into the vessel, the one or more exhausts being oriented along at least a portion of the inner vessel wall so that the gas is caused to flow away from the EUV collector.

A method for inspecting an extreme ultraviolet (EUV) light source includes: removing a collector mirror of the EUV light source from a collector chamber; installing an inspection apparatus within the collector chamber, the apparatus including a selectively extendable and retractable member and a camera at one end of the member; operating a first actuator to extend the member along a path through the interior chamber of the EUV light source, thereby moving the camera to a given position within the interior chamber of the EUV light source; operating a second actuator to pan the camera about an axis of rotation, thereby establishing a given camera orientation within the interior of the EUV light source; and, capturing an image of the interior chamber of the EUV light source with the camera while the camera is at the given position and orientation established by the operation of the first and second actuators.