Abstract: The invention relates to a plasma generator (1) for cleaning an object. The plasma generator (1) comprises a plasma chamber (2) and a support structure (6) arranged in the plasma chamber for supporting the object (7) to be cleaned. Further, the plasma generator comprises an electromagnetic shield (5a, 5b, 5c) counteracting a flow of charged plasma particles flowing from a plasma generating region towards the object, and a plasma source (8). In addition, the plasma generator comprises an additional plasma source (9,10) to form a composition of plasma sources that are arranged to generate in the plasma generating region plasmas, respectively, that mutually interact during operation of the plasma generator so as to force plasma particles to flow in a diffusely closed flow path.

Abstract: The invention relates to a method of manufacturing an electrostatic clamp configured to electrostatically clamp an article to an article support in a lithographic apparatus. The method includes providing a first layer of material, etching a recess in the first layer of material, and disposing an electrode in the recess of the first layer of material.

Abstract: An optical element, especially a normal-incidence collector mirror, for radiation in the EUV and/or soft X-ray region of wavelengths is described. The element has a substrate, a multilayer coating with an optically active region, and a capacitor, having a first and a second capacitor electrode. At least one layer of the multilayer coating serves as the first capacitor electrode. At least one dielectric layer is provided between the two capacitor electrodes. Also described is an optical system with at least one optical element, having a first electrode arranged in the vicinity of the optical element.

Abstract: The invention relates to a method of manufacturing an electrostatic clamp configured to electrostatically clamp an article to an article support in a lithographic apparatus. The method includes providing a first layer of material, etching a recess in the first layer of material, and disposing an electrode in the recess of the first layer of material.

Abstract: An apparatus includes a first support structure configured to support an element that has an alignment marker provided with at least one height difference. The apparatus also includes an alignment sensor comprising a light source that is configured to provide a light beam that illuminates the alignment marker; and at least one detector configured to detect the at least one height difference of the alignment marker by analyzing the light beam reflected by the alignment marker. Such an apparatus may be used to align of the element with respect to the first support structure.

Abstract: The invention relates to a plasma generator (1) for cleaning an object. The plasma generator (1) comprises a plasma chamber (2) and a support structure (6) arranged in the plasma chamber for supporting the object (7) to be cleaned. Further, the plasma generator comprises an electromagnetic shield (5a, 5b, 5c) counteracting a flow of charged plasma particles flowing from a plasma generating region towards the object, and a plasma source (8). In addition, the plasma generator comprises an additional plasma source (9,10) to form a composition of plasma sources that are arranged to generate in the plasma generating region plasmas, respectively, that mutually interact during operation of the plasma generator so as to force plasma particles to flow in a diffusely closed flow path.

Abstract: A lithographic apparatus is disclosed. The apparatus includes an illumination system configured to condition an extreme ultraviolet radiation beam, a patterning device configured to impart the extreme ultraviolet radiation beam with a pattern in its cross-section to form a patterned extreme ultraviolet radiation beam, a substrate table constructed to hold a substrate, a projection system provided with reflective optics configured to project the patterned extreme ultraviolet radiation beam onto a target portion of the substrate, a vacuum chamber constructed to create a vacuum environment, and a detection unit arranged within the vacuum chamber to detect contamination on the patterning device.

Abstract: The invention is directed to enabling substrate identification by comparing the measured distance between two features on an unidentified substrate with one or more stored distances. The one or more stored distances are the distances intended during the design of one or more substrates. The unidentified substrate is identified by a stored distance that corresponds to the measured distance. The two features are selected from a plurality of features that may be placed on a back side or a front side of a substrate. An optical system is provided for reading the features from the back side or a front side of the substrate.

Abstract: An embodiment of the invention may be applied to measure the positions of features in a alignment region on a mask with a sensor. The positions of the features in the alignment region are known from the design. A feature of which the position is measured, is identified by comparing the relative positions between measured features with relative positions known from the design. The known position of the identified feature is subtracted from a measured position of the identified feature to give the position of the mask.