Abstract: Designs are provided to reduce the possibility of contaminant particles with a large range of sizes, materials, travel speeds and angles of incidence reaching a particle-sensitive environment. According to an aspect of the disclosure, there is provided an object stage comprising first and second chambers, a first structure having a first surface, and a second structure. The second structure is configured to support an object in the second chamber, movable relative to the first structure. The second structure comprises a second surface opposing the first surface of the first structure thereby defining a gap between the first structure and the second structure that extends between the first chamber and the second chamber. The second structure further comprises a third surface within the first chamber. The object stage further comprises a trap disposed on at least a portion of the third surface, the trap comprising a plurality of baffles.

Abstract: The disclosure relates to measuring a parameter of a lithographic process and a metrology apparatus. In one arrangement, radiation from a radiation source is modified and used to illuminate a target formed on a substrate using the lithographic process. Radiation scattered from a target is detected and analyzing to determine the parameter. The modification of the radiation comprises modifying a wavelength spectrum of the radiation to have a local minimum between a global maximum and a local maximum, wherein the power spectral density of the radiation at the local minimum is less than 20% of the power spectral density of the radiation at the global maximum and the power spectral density of the radiation at the local maximum is at least 50% of the power spectral density of the radiation at the global maximum.

Abstract: 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.

Abstract: A radiation system includes a beam splitting apparatus configured to split a main radiation beam into a plurality of branch radiation beams and a radiation alteration device arranged to receive an input radiation beam and output a modified radiation beam, wherein the radiation alteration device is configured to provide an output modified radiation beam which has an increased etendue, when compared to the received input radiation beam, wherein the radiation alteration device is arranged such that the input radiation beam which is received by the radiation alteration device is a main radiation beam and the radiation alteration device is configured to provide a modified main radiation beam to the beam splitting apparatus, or wherein the radiation alteration device is arranged such that the input radiation beam which is received by the radiation alteration device is a branch radiation beam output from the beam splitting apparatus.

Abstract: Disclosed is a method and associated inspection apparatus for detecting variations on a surface of a substrate. The method comprises providing patterned inspection radiation to a surface of a substrate. The inspection radiation is patterned such that an amplitude of a corresponding enhanced field is modulated in a manner corresponding to the patterned inspection radiation. The scattered radiation resultant from interaction between the enhanced field and the substrate surface is received and variations on the surface of the substrate are detected based on the interaction between the enhanced field and the substrate surface. Also disclosed is a method of detecting any changes to at least one characteristic of received radiation, the said changes being induced by the generation of a surface plasmon at said surface of the optical element.

Abstract: Methods and apparatus for determining an intensity profile of a radiation beam. The method comprises providing a diffraction structure, causing relative movement of the diffraction structure relative to the radiation beam from a first position wherein the radiation beam does not irradiate the diffraction structure to a second position wherein the radiation beam irradiates the diffraction structure, measuring, with a radiation detector, diffracted radiation signals produced from diffraction of the radiation beam by the diffraction structure as the diffraction structure transitions from the first position to the second position or vice versa, and determining the intensity profile of the radiation beam based on the measured diffracted radiation signals.

Abstract: A delivery system for use within a lithographic system. The beam delivery system comprises optical elements arranged to receive a radiation beam from a radiation source and to reflect portions of radiation along one or more directions to form a one or more branch radiation beams for provision to one or more tools.

Abstract: A radiation alteration device includes a continuously undulating reflective surface, wherein the shape of the continuously undulating reflective surface follows a substantially periodic pattern.

Abstract: An apparatus (60) for adjusting an intensity of radiation. The apparatus comprises a grating (61) for receiving a radiation beam (Ba) and for directing at least a portion of the radiation beam in a first direction in the form of a first reflected radiation beam (Ba0), and one or more first actuators operable to rotate the grating to adjust a grazing angle between the radiation beam and a surface of the grating so as to vary an intensity of the reflected radiation beam.

Abstract: A radiation sensor apparatus for determining a position and/or power of a radiation beam, the radiation sensor apparatus including a chamber to contain a gas, one or more sensors, and a processor. The chamber has a first opening and a second opening such that a radiation beam can enter the chamber through the first opening, propagate through the chamber generally along an axis, and exit the chamber through the second opening. Each of the one or more sensors is arranged to receive and detect radiation emitted from a region of the chamber around the axis. The processor is operable to use the radiation detected by the one or more sensors to determine a position and/or power of the radiation beam.

Abstract: A radiation sensor apparatus for determining a position and/or power of a radiation beam, the radiation sensor apparatus including a chamber to contain a gas, one or more sensors, and a processor. The chamber has a first opening and a second opening such that a radiation beam can enter the chamber through the first opening, propagate through the chamber generally along an axis, and exit the chamber through the second opening. Each of the one or more sensors is arranged to receive and detect radiation emitted from a region of the chamber around the axis. The processor is operable to use the radiation detected by the one or more sensors to determine a position and/or power of the radiation beam.

Abstract: 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.

Abstract: A reflector (2) comprising a plate (4) supported by a substrate (8), wherein the plate has a reflective surface (5) and is secured to the substrate by adhesive free bonding, and wherein a cooling channel array (10) is provided in the reflector. The channels (16) of the cooling channel array may be formed from open channels in a surface of the substrate, the open channels being closed by the plate to create the channels.

Abstract: A beam (542, 556) of inspection radiation is generated by focusing infrared (IR) radiation (540) at a source location so as to generate the inspection radiation (542) by high-harmonic generation in a gas cell (532). An illumination optical system (512) focuses the inspection radiation into a spot (S) of radiation by imaging the source location onto a metrology target (T). In one embodiment, the same illumination optical system forms a spot of the IR radiation onto a target material. A spot of visible radiation is generated by second harmonic generation at the metrology target. The visible spot is observed by an alignment camera (564). A special alignment target (592) may be provided, or material present in or near the metrology target can be used. In another embodiment, the spot is imaged using a portion (758) of the inspection radiation reflected by the target.

Abstract: An adjustable diffraction grating includes: an optical element and a distortion mechanism. The optical element has an optical surface to receive an input radiation beam. The optical element is provided with a plurality of closed channels below the optical surface, above each closed channel the optical surface being formed from a membrane of material. The distortion mechanism includes one or more actuators that are operable to distort the membranes over the closed channels so as to control the shape of the optical surface and to form a periodic structure on the optical surface which acts as a diffraction grating such that the input radiation beam is diffracted from the optical element to form a plurality of angularly separated sub-beams.

Abstract: An adjustable diffraction grating includes: an optical element and a distortion mechanism. The optical element has an optical surface to receive an input radiation beam. The optical element is provided with a plurality of closed channels below the optical surface, above each closed channel the optical surface being formed from a membrane of material. The distortion mechanism includes one or more actuators that are operable to distort the membranes over the closed channels so as to control the shape of the optical surface and to form a periodic structure on the optical surface which acts as a diffraction grating such that the input radiation beam is diffracted from the optical element to form a plurality of angularly separated sub-beams.

Abstract: A beam-splitting apparatus arranged to receive an input radiation beam and split the input radiation beam into a plurality of output radiation beams. The beam-splitting apparatus comprising a plurality of reflective diffraction gratings arranged to receive a radiation beam and configured to form a diffraction pattern comprising a plurality of diffraction orders, at least some of the reflective diffraction gratings being arranged to receive a 0th diffraction order formed at another of the reflective diffraction gratings. The reflective diffraction gratings are arranged such that the optical path of each output radiation beam includes no more than one instance of a diffraction order which is not a 0th diffraction order.

Abstract: 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.

Abstract: A reflector (2) comprising a plate (4) supported by a substrate (8), wherein the plate has a reflective surface (5) and is secured to the substrate by adhesive free bonding, and wherein a cooling channel array (10) is provided in the reflector. The channels (16) of the cooling channel array may be formed from open channels in a surface of the substrate, the open channels being closed by the plate to create the channels.

Abstract: An apparatus (60) for adjusting an intensity of radiation. The apparatus comprises a grating (61) for receiving a radiation beam (Ba) and for directing at least a portion of the radiation beam in a first direction in the form of a first reflected radiation beam (Ba0), and one or more first actuators operable to rotate the grating to adjust a grazing angle between the radiation beam and a surface of the grating so as to vary an intensity of the reflected radiation beam.