An optical system of a microlithographic projection exposure apparatus designed for an operating wavelength of at least 150 nm. In one disclosed aspect, the optical system includes an element (11, 21) producing an angular distribution for light incident during the operation of the optical system and a fly's eye condenser (200, 400, 500) which includes two arrangements (210, 220, 410, 420, 510, 520) following one another in the light propagation direction and made of beam-deflecting optical elements (211-213, 221-223, 411-413, 421-423, 511-513, 521-523), which produce a multiplicity of optical channels. No optical element with refractive power is arranged in the beam path between the element (11, 21) producing an angular distribution and the fly's eye condenser (200, 400, 500).

An overlay metrology target (T) is formed by a lithographic process. A first image (740(0)) of the target structure is obtained using with illuminating radiation having a first angular distribution, the first image being formed using radiation diffracted in a first direction (X) and radiation diffracted in a second direction (Y). A second image (740(R)) of the target structure using illuminating radiation having a second angular illumination distribution which the same as the first angular distribution, but rotated 90 degrees. The first image and the second image can be used together so as to discriminate between radiation diffracted in the first direction and radiation diffracted in the second direction by the same part of the target structure. This discrimination allows overlay and other asymmetry-related properties to be measured independently in X and Y, even in the presence of two-dimensional structures within the same part of the target structure.

A lithographic system including a lithographic apparatus with an anamorphic projection system, and a radiation source configured to generate an EUV radiation emitting plasma at a plasma formation location, the EUV radiation emitting plasma having an elongate form in a plane substantially perpendicular to an optical axis of the radiation source.

A projection objective of a microlithographic projection exposure apparatus contains a plurality of optical elements arranged in N>2 successive sections A.sub.1 to A.sub.N of the projection objective which are separated from one another by pupil planes or intermediate image planes. According to the invention, in order to correct a wavefront deformation, at least two optical elements each have an optically active surface locally reprocessed aspherically. A first optical element is in this case arranged in one section A.sub.j, j=1 . . . N and a second optical element is arranged in another section A.sub.k, k=1 . . . N, the magnitude difference |kj| being an odd number.

The disclosure provides an optical system, having a first optical control loop, which is set up to regulate a position and/or spatial orientation of a first optical element relative to a first module sensor frame, and a first module control loop, which is set up to regulate a position and/or spatial orientation of the first module sensor frame relative to a base sensor frame. Related components and methods are also provided

Dioptric projection lens for imaging a pattern in an object plane into an image plane via electromagnetic radiation at an operating wavelength in the ultraviolet range of longer than 280 nm comprises a multiplicity of lens elements between the object plane and the image plane along an optical axis configured so that a pattern in the object plane is able to be imaged into the image plane via the lens elements, with a stop plane suitable for attaching an aperture stop between the object plane and the image plane, a chief ray of the imaging intersecting the optical axis in the stop plane. The projection lens is designed as a large field lens with an object field radius of at least 52 mm and has a structure with an imaging scale of 1:1 which is mirror symmetric with respect to the stop plane.

A projection objective of a microlithographic projection exposure apparatus contains a plurality of optical elements arranged in N>2 successive sections A.sub.1 to A.sub.N of the projection objective which are separated from one another by pupil planes or intermediate image planes. According to the invention, in order to correct a wavefront deformation, at least two optical elements each have an optically active surface locally reprocessed aspherically. A first optical element is in this case arranged in one section A.sub.j, j=1 . . . N and a second optical element is arranged in another section A.sub.k, k=1 . . . N, the magnitude difference |kj| being an odd number.

An optical system of a microlithographic projection exposure apparatus designed for an operating wavelength of at least 150 nm. In one disclosed aspect, the optical system includes an element (11, 21) producing an angular distribution for light incident during the operation of the optical system and a fly's eye condenser (200, 400, 500) which includes two arrangements (210, 220, 410, 420, 510, 520) following one another in the light propagation direction and made of beam-deflecting optical elements (211-213, 221-223, 411-413, 421-423, 511-513, 521-523), which produce a multiplicity of optical channels. No optical element with refractive power is arranged in the beam path between the element (11, 21) producing an angular distribution and the fly's eye condenser (200, 400, 500).

A projection objective of a microlithographic projection exposure apparatus contains a plurality of optical elements arranged in N>2 successive sections A.sub.1 to A.sub.N of the projection objective which are separated from one another by pupil planes or intermediate image planes. According to the invention, in order to correct a wavefront deformation, at least two optical elements each have an optically active surface locally reprocessed aspherically. A first optical element is in this case arranged in one section A.sub.j, j=1 . . . N and a second optical element is arranged in another section A.sub.k, k=1 . . . N, the magnitude difference |kj| being an odd number.

A first diffusor configured to receive and transmit radiation has a plurality of layers, each layer arranged to change an angular distribution of EUV radiation passing through it differently. A second diffusor configured to receive and transmit radiation has a first layer and a second layer. The first layer is formed from a first material, the first layer including a nanostructure on at least one surface of the first layer. The second layer is formed from a second material adjacent to the at least one surface of the first layer such that the second layer also includes a nanostructure. The second material has a refractive index that is different to a refractive index of the first layer. The diffusors may be configured to receive and transmit EUV radiation.