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).

A magnifying imaging optical unit serves for inspecting lithography masks which are used in EUV projection exposure. The imaging optical unit comprises at least two mirrors (M1 to M4) which can be displaced relative to one another for changing a magnification value. According to a further aspect, a magnifying imaging optical unit comprises at least one mirror (M1 to M4) and a magnification value, which can be changed by displacement of at least two mirrors (M1 to M4) relative to one another. Here, the magnification value can be changed between a minimum magnification value, which is greater than 100, and a maximum magnification value, which is greater than 200. An imaging optical unit emerges, which can be adapted to, in particular, mask structures with different sizes.

An all-reflective coronagraph optical system for continuously imaging a wide field of view. The optical system can comprise a fore-optics assembly comprising a plurality of mirrors that reflect light rays, about a wide field of view centered around the Sun, to an aft-optics assembly that reflects the light rays to an image sensor. A fold mirror, having an aperture, is optically supported between the fore-optics assembly and the aft-optics assembly. The aperture defines an angular subtense (e.g., 1.0 degree) sized larger than the angular subtense of the Sun. The aperture facilitates passage of a direct solar image and a solar thermal load. A thermal control subsystem comprises a shroud radiatively coupled to each fore-optics mirror and the fold mirror. A cold radiator is thermally coupled to each shroud. Heaters adjacent fore optics mirrors and the fold mirror control temperature to provide a steady state optical system to minimize wavefront error.

A catoptric system for EUV lithography includes six freeform reflective surfaces that are specified based on fringe Zernike polynomials. Each of the surfaces is tilted and/or decentered in a meridian plane and with respect to a common axis so that image and object planes are parallel. Rectangular fields can be imaged with image space numerical aperture of at least 0.5.

An imaging optical unit for projection lithography has a plurality of mirrors for guiding imaging light from an object field in an object plane into an image field in an image plane along an imaging light beam path. At least two of the mirrors are embodied as GI mirrors. Exactly one stop serves to predefine at least one section of an outer marginal contour of a pupil of the imaging optical unit. The stop is arranged spatially in front of a penultimate mirror in the imaging light beam path. This results in an imaging optical unit that is well defined with regard to its pupil and is optimized for projection lithography.

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).

A light source apparatus including a light source configured to emit a light flux from an emission region having a predetermined size and a rotationally symmetrical emission intensity distribution; and a condenser configured to condense the light flux to allow the light flux to exit to the outside. The condenser is rotationally symmetrical about an optical axis and is disposed to surround the emission region, and has four or more reflection mirrors each having a reflecting surface for reflecting the light flux emitted from the emission region. The reflection mirrors include elliptical surface reflection mirrors where the reflecting surface is elliptical and spherical surface reflection mirrors where the reflecting surface is spherical, and are alternately arranged in the direction of the optical axis, and a light flux reflected by one spherical surface reflection mirror is further reflected by one elliptical surface reflection mirror oppositely disposed across the emission region.

A method for designing an imaging objective lens system with an anamorphic magnification. The method includes the following steps: designing a coaxial overall spherical imaging objective lens system A with an M magnification; only using the curvatures of reflectors in the system A as optimization variables to optimize the system A into a system B with an N magnification; transforming the reflectors in the system A to have an anamorphic aspherical surface profile, wherein the longitudinal curvature of each anamorphic aspherical surface remains unchanged, and the transverse curvature is the curvature of the corresponding reflector in the system B; and obtaining an anamorphic magnification imaging system C with an M longitudinal magnification and an N transverse magnification. The imaging objective lens system designed with the method can realize different magnification in different directions.

An illumination optical system which is used with a reflective imaging optical system configured to form an image of a pattern arranged on a first plane onto a second plane, and which illuminates an illumination area on the first plane with a light from a light source. The illumination optical system includes one or more reflecting mirrors configured to reflect the light from the light source such that the light from the light source passes between first and second mirrors of a plurality of mirrors provided in the reflective imaging optical system, the first mirror being configured to reflect the light from the pattern first, and the second mirror being configured to reflect the light from the pattern second.

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).