A method for mitigating an effect of non-uniform pellicle degradation on control of a substrate patterning process and an associated lithographic apparatus. The method includes quantifying an effect of the non-uniform pellicle degradation on one or more properties of patterned features, such as one or more metrology targets, formed on the substrate by the substrate patterning process. A process control correction is then determined based on the quantification of the effect of the non-uniform pellicle degradation.

There is provided a substrate holding apparatus including a base provided with a gap and a reflection member disposed in the gap and configured to reflect light that has transmitted the substrate to the substrate side, and an exposure apparatus including the substrate holding apparatus.

The disclosure relates to a device for transmitting electrical signals between a first interface element, arranged at a first structure of a lithography system, and a second interface element, arranged at a second structure of the lithography system. An electrical conductor connects the first interface element and the second interface element. The device has a hollow body which surrounds at least sections of the electrical conductor and which is designed to electromagnetically shield the electrical conductor. A gap is provided in the hollow body or between the hollow body and one of the structures and allows a relative movement of the first structure and the second structure to mechanically decouple the first structure from the second structure.

Disclosed is a method of mitigating for a process dependent stray light artifact on a measurement a structure. The method comprises obtaining a calibration scaling factor for the process dependent stray light artifact based on a reference angle resolved measurement and target angle resolved measurement, and a correction of an image with the obtained calibration scaling factor.

Methods and apparatus are disclosed for determining a characteristic of a structure. In one arrangement, the structure is illuminated with first illumination radiation to generate first scattered radiation. A first interference pattern is formed by interference between a portion of the first scattered radiation reaching a sensor and first reference radiation. The structure is also illuminated with second illumination radiation from a different direction. A second interference pattern is formed using second reference radiation. The first and second interference patterns are used to determine the characteristic of the structure. Azimuthal angles of the first and second reference radiations onto the sensor are different.

For the purposes of positioning a component part, provision is made in an optical system for a stray magnetic field to be detected via a sensor device and for a correction signal for compensating the effect of the stray magnetic field on the positioning of the component part to be ascertained.

A method for reducing an effect of flare produced by a lithographic apparatus for imaging a design layout onto a substrate is described. A flare map in an exposure field of the lithographic apparatus is simulated by mathematically combining a density map of the design layout at the exposure field with a point spread function (PSF), wherein system-specific effects on the flare map may be incorporated in the simulation. Location-dependent flare corrections for the design layout are calculated by using the determined flare map, thereby reducing the effect of flare.

A wavefront of a light beam that exits an acousto-optic material is estimated; a control signal for an acousto-optic system that includes the acousto-optic material is generated, the control signal being based on the estimated wavefront of the light beam; and the control signal is applied to the acousto-optic system to generate a frequency-chirped acoustic wave that propagates in the acousto-optic material, the frequency-chirped acoustic wave forming a transient diffractive element in the acousto-optic material, an interaction between the transient diffractive element and the light beam adjusting the wavefront of the light beam to compensate for a distortion of the wavefront of the light beam, the distortion of the wavefront being at least partially caused by a physical effect in the acousto-optic material.

Disclosed is a photolithography (e.g., extreme ultraviolet (EUV) photolithography) system that incorporates a photomask-pellicle apparatus with an angled pellicle. The apparatus includes a photomask structure and a pellicle structure that is mounted on the photomask structure. The pellicle is essentially transparent to a given-type radiation (e.g., EUV radiation), is essentially reflective to out-of-band (OOB) radiation, and is positioned at an angle relative to the photomask. When radiation is directed toward the photomask-pellicle apparatus during a photolithographic exposure process, beams that are reflected and diffracted off of the patterned surface of the photomask structure are directed toward a target semiconductor wafer and beams that are reflected and diffracted off of the pellicle are directed away from the target semiconductor wafer. Aiming the OOB radiation away from the target semiconductor wafer improves imaging quality by minimizing the negative impact of OOB radiation. Also disclosed is an associated photolithography method.

An illumination optical unit for EUV projection lithography illuminates an object field with illumination light. The illumination optical unit has a first facet mirror including a plurality of first facets on a first mirror carrier. Disposed downstream of the first facet mirror is a second facet mirror including a plurality of second facets arranged on a second mirror carrier around a facet arrangement center. Partial beams of the illumination light are guided superposed on one another into the object field, respectively via illumination channels which have one of the first facets and one of the second facets. Second maximum angle facets are arranged at the edge of the second mirror carrier. The second maximum angle facets predetermine maximum illumination angles of the illumination light which deviate maximally from a chief ray incidence on the object field.