A method of making a polarizer can include applying a liquid with solid inorganic nanoparticles dispersed throughout a continuous phase, then forming this into a different phase including a solid, interconnecting network of the inorganic nanoparticles. This method can improve manufacturability and reducing manufacturing cost. This method can be used to provide an antireflective coating, to provide a protective coating on polarization structures, to provide thin films for optical properties, or to form the polarization structures themselves.

The invention relates to a method and an apparatus for characterizing a microlithographic mask. In a method according to the invention, structures of a mask intended for use in a lithography process in a microlithographic projection exposure apparatus are illuminated by an illumination optical unit, wherein the mask is imaged onto a detector unit which has a plurality of pixels by an imaging optical unit. Here, a plurality of individual imaging processes are carried out with a pixel resolution specified by the detector unit, wherein these individual imaging processes differ from one another in respect of the position of at least one polarization-optical element situated in the imaging optical unit, wherein image data recorded by the detector unit are evaluated in an evaluation unit, wherein polarization-dependent effects on account of a polarization dependence of the interference of electromagnetic radiation that takes place in the wafer plane during the operation of the microlithographic projection exposure apparatus are emulated, wherein a conversion of the image data obtained in the individual imaging processes is implemented, in each case on the basis of at least one calibration image obtained by imaging a structure-free region of the mask onto the detector unit, wherein the calibration image respectively used is chosen differently depending on the position of the at least one polarization-optical element.

A projection optical unit for microlithography includes a plurality of mirrors and has a numerical aperture having a value larger than 0.5. The plurality of mirrors includes at least three grazing incidence mirrors, which deflect a chief ray of a central object field point with an angle of incidence of greater than 45°. Different polarized light beams passing the projection optical unit are rotated in their polarization direction by different angles of rotation. The projection optical unit includes first and second groups of mirrors. The second group of mirrors includes the final two mirrors of the plurality of mirrors at the image side. A linear portion in the pupil dependence of the total geometrical polarization rotation of the projection optical unit is less than 20% of a linear portion in the pupil dependence of the geometrical polarization rotation of the second group of mirrors.

An illumination optical system of the present invention includes a first lens array FE including a plurality of lens cells dividing a light flux emitted from a light source into a plurality of light fluxes, a second lens array MLAi including lens cells on which spot lights exiting from the lens cells included in the first lens array FE are condensed, and a first optical member IL3 imaging the spot light, which has been condensed on the lens cell included in the second lens array MLAi, on one of optical modulation elements constituting an optical modulation unit.

A method of making a polarizer can include applying a liquid with solid inorganic nanoparticles dispersed throughout a continuous phase, then forming this into a different phase including a solid, interconnecting network of the inorganic nanoparticles. This method can improve manufacturability and reducing manufacturing cost. This method can be used to provide an antireflective coating, to provide a protective coating on polarization structures, to provide thin films for optical properties, or to form the polarization structures themselves.

An illumination optical system of the present invention includes a first lens array FE including a plurality of lens cells dividing a light flux emitted from a light source into a plurality of light fluxes, a second lens array MLAi including lens cells on which spot lights exiting from the lens cells included in the first lens array FE are condensed, and a first optical member IL3 imaging the spot light, which has been condensed on the lens cell included in the second lens array MLAi, on one of optical modulation elements constituting an optical modulation unit.

A projection optical unit for microlithography includes a plurality of mirrors and has a numerical aperture having a value larger than 0.5. The plurality of mirrors includes at least three grazing incidence mirrors, which deflect a chief ray of a central object field point with an angle of incidence of greater than 45°. Different polarized light beams passing the projection optical unit are rotated in their polarization direction by different angles of rotation. The projection optical unit includes first and second groups of mirrors. The second group of mirrors includes the final two mirrors of the plurality of mirrors at the image side. A linear portion in the pupil dependence of the total geometrical polarization rotation of the projection optical unit is less than 20% of a linear portion in the pupil dependence of the geometrical polarization rotation of the second group of mirrors.

The invention relates to a method and an apparatus for characterizing a microlithographic mask. In a method according to the invention, structures of a mask intended for use in a lithography process in a microlithographic projection exposure apparatus are illuminated by an illumination optical unit, wherein the mask is imaged onto a detector unit which has a plurality of pixels by an imaging optical unit. Here, a plurality of individual imaging processes are carried out with a pixel resolution specified by the detector unit, wherein these individual imaging processes differ from one another in respect of the position of at least one polarization-optical element situated in the imaging optical unit, wherein image data recorded by the detector unit are evaluated in an evaluation unit, wherein polarization-dependent effects on account of a polarization dependence of the interference of electromagnetic radiation that takes place in the wafer plane during the operation of the microlithographic projection exposure apparatus are emulated, wherein a conversion of the image data obtained in the individual imaging processes is implemented, in each case on the basis of at least one calibration image obtained by imaging a structure-free region of the mask onto the detector unit, wherein the calibration image respectively used is chosen differently depending on the position of the at least one polarization-optical element.

A method of making a polarizer can include applying a liquid with solid inorganic nanoparticles dispersed throughout a continuous phase, then forming this into a different phase including a solid, interconnecting network of the inorganic nanoparticles. This method can improve manufacturability and reducing manufacturing cost. This method can be used to provide an antireflective coating, to provide a protective coating on polarization structures, to provide thin films for optical properties, or to form the polarization structures themselves.

A beam-splitting apparatus arranged to receive an input radiation beam and split the input radiation beam into a plurality of output radiation beams. The beam-splitting apparatus comprising a plurality of reflective diffraction gratings arranged to receive a radiation beam and configured to form a diffraction pattern comprising a plurality of diffraction orders, at least some of the reflective diffraction gratings being arranged to receive a 0.sup.th diffraction order formed at another of the reflective diffraction gratings. The reflective diffraction gratings are arranged such that the optical path of each output radiation beam includes no more than one instance of a diffraction order which is not a 0.sup.th diffraction order.