The present disclosure relates to systems and methods relating to the fabrication of light guide elements. An example system includes an optical component configured to direct light emitted by a light source to illuminate a photoresist material at one or more desired angles so as to expose an angled structure in the photoresist material. The photoresist material overlays at least a portion of a first surface of a substrate. The optical component includes a container containing a light-coupling material that is selected based in part on the one or more desired angles. The system also includes a reflective surface arranged to reflect at least a first portion of the emitted light to illuminate the photoresist material at the one or more desired angles.

A microscope system for flexibly, efficiently and quickly inspecting patterns and defects on extreme ultraviolet (EUV) lithography photomasks. The system includes a stand-alone plasma-based EUV radiation source with an emission spectrum with a freestanding line emission in the spectral range from 12.5 nm to 14.5 nm has a relative bandwidth of λ/Δλ>1000, means for the broadband spectral filtering λ/Δλ<50 for selecting the dominant freestanding emission line, means for suppressing radiation with wavelengths outside of the EUV spectral region, zone plate optics for magnified imaging of the object with a resolution which corresponds to the width of an outermost zone of the zone plate, a numerical aperture corresponding to more than 1000 zones, and a EUV detector array for capturing the patterned object.

A method includes: receiving a photomask; patterning a wafer by directing a first radiation beam to the wafer through the photomask at a first tilt angle; and inspecting the photomask. The inspecting includes: directing a second radiation beam to the photomask at a second tilt angle greater than the first tilt angle; receiving a third radiation beam reflected from the photomask; and generating an image of the photomask according to the third radiation beam.

An illumination optical unit for EUV projection lithography includes a field facet mirror with a plurality of field facets for guiding illumination light into an object field where a lithography mask is arrangeable. At least one spectral output coupling mirror section is arranged on the field facet mirror. The mirror section serves to output couple the spectral analysis partial beam from a beam path of the illumination light. A detector serves for the spectral analysis of the spectral analysis partial beam. This can yield an illumination optical unit in which process monitoring during the projection exposure is improved.

An optical effect device (300) comprising: a substrate (302) having a first surface (304) and a second surface (306); a plurality of structures (308) arranged on the first surface (304), each structure (308) having a first facet (310) and a second facet (314), the first facet (310) of each structure (308) being substantially parallel to the first surface (304) of the substrate (302), the second facet (314) of each structure (308) defining a slope with respect to the first surface (304), and the first facets (310) of the plurality of structures (308) forming a first facet set. The first facet set defines a first optical effect when the optical effect device (300) is viewed from a first viewing angle range

A collector mirror for an extreme ultraviolet (EUV) light generator includes a first mirror in a vessel, the vessel being configured to receive a material and a laser beam for generating the EUV light, a second mirror surrounding the first mirror, and a detachable third mirror between the first mirror and the second mirror, the third mirror having an inner diameter that is not smaller than an outer diameter of the first mirror, and an outer diameter that is not larger than an inner diameter of the second mirror.

An extreme ultra violet (EUV) light source apparatus includes a metal droplet generator, a collector mirror, an excitation laser inlet port for receiving an excitation laser, a first mirror configured to reflect the excitation laser that passes through a zone of excitation, and a second mirror configured to reflect the excitation laser reflected by the first mirror.

There is provided a reflective image-forming optical system which is applicable to an exposure apparatus using, for example, EUV light and which is capable of increasing numerical aperture while enabling optical path separation of light fluxes. In a reflective imaging optical system (6) forming an image of a first plane (4) onto a second plane (7), the numerical aperture on a side of the second plane with respect to a first direction (X direction) on the second plane is greater than 1.1 times a numerical aperture on the side of the second plane with respect to a second direction (Y direction) crossing the first direction on the second plane. The reflecting imaging optical system has an aperture stop (AS) defining the numerical aperture on the side of the second plane, and the aperture stop has an elliptic-shaped opening of which size in a major axis direction (X direction) is greater than 1.1 times that in a minor axis direction (Y direction).

An EUV collector has a reflection surface with a basic mirror shape of a spherical section. A diffraction grating for EUV used light is applied to the reflection surface. The diffraction grating is designed so that the EUV used light, which emanates from a sphere center of the spherical section, is diffracted by the diffraction grating toward a collection region. The collection region is spatially spaced apart from the sphere center. This creates an EUV collector in which an effective separation between EUV used light, which is to be collected with the aid of the collector, and extraneous light having a wavelength that differs from a used light wavelength is made possible.

A reflective optical element (17), in particular for an illumination optical unit of a projection exposure apparatus includes: a structured surface (25a) that preferably forms a grating structure (29), and a reflective coating (36) that is applied to the structured surface (25a). The reflective coating (36) covers the structured surface (25a) discontinuously, and the reflective optical element (17) has at least one protective layer (37) that covers the structured surface (25a) continuously. Also disclosed are an illumination optical unit (4) for a projection exposure apparatus (1) including at least one reflective optical element (17) of this type, to a projection exposure apparatus (1) including an illumination optical unit (4) of this type, and to a method for producing a protective layer (37) on a reflective optical element (17) of this type.