Disclosed is a system configured to project a beam of radiation onto a target portion of a substrate within a lithographic apparatus. The system comprises a mirror having an actuator for positioning the mirror and/or configuring the shape of the mirror, the actuator also providing active damping to the mirror, and a controller for generating actuator control signals for control of said actuator(s). A first coordinate system is used for control of said actuator(s) when positioning said mirror and/or configuring the shape of said mirror and a second coordinate system is used for control of said actuator(s) when providing active damping to said mirror.

An optical system (OS) for focusing a beam of radiation (B) on a region of interest in a metrology apparatus is described. The beam of radiation (B) comprises radiation in a soft X-ray or Extreme Ultraviolet spectral range. The optical system (OS) comprises a first stage (S1) for focusing the beam of radiation at an intermediate focus region. The optical system (OS) comprises a second stage (S2) for focusing the beam of radiation from the intermediate focus region onto the region of interest. The first and second stages each comprise a Kirkpatrick-Baez reflector combination. At least one reflector comprises an aberration-correcting reflector.

A device and method for producing light-exposed structures on a workpiece having a light-sensitive surface. An optical unit includes a light source and a diffraction grating for producing a strip-shaped illumination pattern having strips extending in a longitudinal direction and having a pattern width extending transversely. A device moves the surface of the workpiece and optical unit relative to each other according to a path sequence, which includes movement longitudinal paths to produce a first and second light-exposed structure having strips, which is oriented parallel to each other on the workpiece surface. The movement paths are mutually spaced apart by less than the pattern width and the light-exposed structures overlap in such a way that strips of the light-exposed structures lie on each other. To obtain good light exposure of the surface by the illumination pattern, the diffraction grating is set oblique to the surface of the workpiece that is light-exposed by the illumination pattern.

An optical diffraction component is configured to suppress at least one target wavelength by destructive interference. The optical diffraction component includes at least three diffraction structure levels that are assignable to at least two diffraction structure groups. A first of the diffraction structure groups is configured to suppress a first target wavelength .sub.1. A second of the diffraction structure groups is configured to suppress a second target wavelength .sub.2, where (.sub.1.sub.2).sup.2/(.sub.1+.sub.2).sup.2<20%. A topography of the diffraction structure levels can be described as a superimposition of two binary diffraction structure groups. Boundary regions between adjacent surface sections of each of the binary diffraction structure groups have a linear course and are superimposed on one another at most along sections of the linear course.

An alignment system aligns a laser beam to a desired position in a reference plane and to a desired direction in the reference plane. The system diffracts the laser light into different diffraction orders that are projected onto a detection plane using different lenses. As the locations of the projections of the different diffraction orders in the detection plane respond differently to changes in position and in direction of the beam in the reference plane, the locations of the projections enable to determine how to adjust the beam so as to get the beam properly aligned. The diffraction and the projection can be implemented by a hologram.

Various methods are disclosed herein for reducing (or eliminating) printability of mask defects during lithography processes. An exemplary method includes performing a first lithography exposing process and a second lithography exposing process using a mask to respectively image a first set of polygons oriented substantially along a first direction and a second set of polygons oriented substantially along a second direction on a target. During the first lithography exposing process, a phase distribution of light diffracted from the mask is dynamically modulated to defocus any mask defect oriented at least partially along both the first direction and a third direction that is different than the first direction. During the second lithography exposing process, the phase distribution of light diffracted from the mask is dynamically modulated to defocus any mask defect oriented at least partially along both the second direction and a fourth direction that is different than the third direction.

An exposure apparatus is provided. An illumination optical system in the apparatus includes a diffraction optical element, a condensing optical system a detector that detects a light beam that exited from the condensing optical system, and a first diaphragm that can be inserted/removed in/from a position near a predetermined plane in an optical path where the condensing optical system condenses a light beam. The first diaphragm has an opening diameter such that an output of the detector decreases when an incident angle of light from a light source on the diffraction optical element deviates from a target angle. Based on an output of the detector when the first diaphragm is inserted in the position and an output of the detector when the first diaphragm is retracted from the position, a controller performs a process of adjusting the incident angle.

Disclosed is a suppression filter having a profile defining at least two reflective surface levels, each reflected surface level being separated by a separation distance. The separation distance is such that the reflective suppression filter is operable to substantially prevent specular reflection of radiation at a first wavelength and at a second wavelength incident on said reflective suppression filter. Also disclosed is a radiation collector, radiation source and lithographic apparatus comprising such a suppression filter, and to a method of determining a separation distance between at least two reflective surface levels of a suppression filter.

A metrology apparatus for determining a characteristic of interest of a structure on a substrate, the structure having diffractive properties, the apparatus comprising: focusing optics configured to focus illumination radiation comprising a plurality of wavelengths onto the structure; a first detector configured to detect at least part of the illumination radiation which has been diffracted from the structure; and additional optics configured to produce, on at least a portion of the first detector, a wavelength-dependent spatial distribution of different wavelengths of the illumination radiation which has been diffracted from the structure, wherein the first detector is arranged to detect at least a non-zero diffraction order of the illumination radiation which has been diffracted from the structure.

The present application is directed to an improved immersion grating assembly that provides additional wavelength dispersion and higher optical efficiency at ultraviolet wavelengths relative to prior art devices. More specifically, the immersion grating disclosed herein may be used to narrow the spectrum of light emitted by excimer laser systems. Narrower spectral linewidth of excimer laser systems may enable the creation of smaller feature sizes in semiconductor structures manufactured using UV photolithography processes.