A system and method for patterning of a substrate at sub-micron length scales using interference lithography that includes a substrate; a chuck that promotes substrate motion; at least two EM beams; a beam phase controller, wherein the phase controller modifies phases of the EM beams with respect to each other creating an interference pattern; a displacement sensor that measures the substrate displacement; and a feedback control mechanism configured to monitor and synchronize the substrate motion with the interference pattern using the beam phase controller and the displacement sensor.

A method of reducing an aberration of a lithographic apparatus, the method including measuring the aberration, taking the measured aberration into account, estimating a state of the lithographic apparatus, calculating a correction using the estimated state, and applying the correction to the lithographic apparatus.

A method for improving a design of a patterning device. The method includes (i) obtaining mask points of a design of a mask feature, wherein the mask feature corresponds to a target feature in a target pattern to be printed on a substrate; and (ii) adjusting locations of the mask points to generate a modified design of the mask feature based on the adjusted mask points.

A method for improving imaging properties of an optical system and an optical system of this type having improved imaging properties are described. The optical system can have a plurality of optical elements. In some embodiments, an optical element is positioned and/or deformed by mechanical force action and by thermal action. In certain embodiments, one optical element is positioned and/or deformed by mechanical force action and another optical element is deformed by thermal action.

An optical element for a lithographic apparatus, the optical element including an anchor layer selected to support a top layer having self-terminating growth in an operating lithographic apparatus or plasma containing environment. Also described is a method of manufacturing an optical element, the method including depositing a top layer on anchor layer via exposure to plasma, preferably electromagnetically induced plasma. Lithographic apparatuses including such optical elements are also described.

The invention relates to a method for compensating at least one defect of an optical system which includes introducing an arrangement of local persistent modifications in at least one optical element of the optical system, which does not have pattern elements on one of its optical surfaces, so that the at least one defect is at least partially compensated.

A method for manufacturing a membrane assembly for EUV lithography, the method including: providing a stack including: at least one membrane layer supported by a planar substrate, wherein the planar substrate has an inner region and a border region around the inner region; and a first sacrificial layer between the planar substrate and the membrane layer; selectively removing the inner region of the planar substrate such that the membrane assembly has: a membrane formed from the at least one membrane layer, and a border holding the membrane, the border having the border region of the planar substrate and the first sacrificial layer situated between the border region and the membrane layer, wherein the selectively removing the inner region of the planar substrate includes using an etchant which has a similar etch rate for the membrane layer and its oxide and a substantially different etch rate for the first sacrificial layer.

The disclosure relates to a microlithographic projection exposure apparatus, such as are used for the production of large-scale integrated electrical circuits and other microstructured components. The disclosure relates in particular to coatings of optical elements in order to increase or reduce the reflectivity.

A projection exposure apparatus (1) for semiconductor lithography, has a device for determining the concentration of atomic hydrogen in a plasma (29) in the region of an optical element (25, 25.1), wherein the device includes a sensor (32, 32.1, 32.2, 32.3, 32.4), In this case, the device includes a filter element (31, 31.1,31.2, 31.3, 31.4) arranged between the region of the plasma (29) and the sensor (32, 32.1, 32.2, 32.3, 32.4), wherein the filter element (31, 31.1,31.2, 31.3, 31.4) is configured to predominantly allow the passage of atomic hydrogen from the plasma (29) to the sensor (32, 32.1, 32.2, 32.3, 32.4).

A polarization-modulating element for modulating a polarization state of incident light into a predetermined polarization state, the polarization-modulating element being made of an optical material with optical activity and having a circumferentially varying thickness profile.