Abstract: An alignment sensor apparatus includes an illumination system, a first optical system, a second optical system, a detector system, and a processor. The illumination system is configured to transmit an illumination beam along an illumination path. The first optical system is configured to transmit the illumination beam toward a diffraction target on a substrate. The second optical system includes a first polarizing optic configured to separate and transmit an irradiance distribution. The detector system is configured to measure a center of gravity of the diffraction target based on the irradiance distribution outputted from a first polarization branch and a second polarization branch. The processor is configured to measure a shift in the center of gravity of the diffraction target caused by an asymmetry variation in the diffraction target and determine a sensor response function of the alignment sensor apparatus based on the center of gravity shift.

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: A compensator for manipulating a radiation beam traveling along an optical path. The compensator includes a fixed support holding a first optical wedge and an adjustable support holding a second optical wedge. The adjustable support includes a base, a stage holding the second optical wedge, first and second flexures, and a drive block. The stage defines a cavity and is movable relative to the base and the fixed support. The first and second flexures couple the stage to the base such that the stage translates along a stage path. The drive block is disposed in the cavity of the stage and is configured to translate along a drive block path perpendicular to the optical path and perpendicular to the stage path. The drive block includes first and second drive bearing surfaces configured to translate the stage in first and second stage directions, respectively, along the stage path.

Abstract: An alignment mark for determining a two-dimensional alignment position of a substrate is discussed. The alignment mark includes an array of patterns. The array of patterns includes a first set of patterns and a second set of patterns arranged. The first set of patterns is arranged in a first sequence along a first direction. The second set of patterns is arranged in a second sequence along the first direction. The second sequence is different from the first sequence. Each pattern of the array of patterns is different from other patterns of the array of patterns that are adjacent to the each pattern.

Abstract: A lithographic apparatus that includes an illumination system that conditions a radiation beam, a first stationary plate having a first surface, and a reticle stage defining, along with the first stationary plate, a first chamber. The reticle stage supports a reticle in the first chamber, and the reticle stage includes a first surface spaced apart from a second surface of the first stationary plate, thereby defining a first gap configured to suppress an amount of contamination passing from a second chamber to the first chamber. The first stationary plate is between the reticle stage and both the illumination system and a projection system configured to project a pattern imparted to the radiation beam by the patterning device onto a substrate.

Abstract: According to one embodiment, a prism system is provided. The prism system includes a polarizing beam splitter (PBS) surface. The PBS surface is configured to generate first and second sub-beams having corresponding first and second polarization information from a received beam, the second polarization information being different than the first polarization information. A first optical path of the first sub-beam within the prism system has substantially same length as a second optical path of the second sub-beam within the prism system. Additionally or alternatively, the first sub-beam achieves a predetermined polarization extinction ratio.

Abstract: A pellicle suitable for use with a patterning device for a lithographic apparatus. The pellicle comprising at least one breakage region which is configured to preferentially break, during normal use in a lithographic apparatus, prior to breakage of remaining regions of the pellicle. At least one breakage region comprises a region of the pellicle which has a reduced thickness when compared to surrounding regions of the pellicle.

Abstract: A method and apparatus to measure a target (e.g., an alignment mark (e.g., on a substrate)) is disclosed. Relative movement between the target and a measurement spot of a measurement system in a “fly-in” direction (e.g., movement of the target towards the measurement spot) is performed so that a first measurement for the target can be made. Thereafter, relative movement between the target and the measurement spot is made in an opposite “fly-in” direction so that a second measurement for the target can be made. By combining (e.g., averaging) these two measurements, an error is cancelled out, and higher accuracy in the measurement may be achieved.

Abstract: Various burl designs for holding an object in a lithographic apparatus are described. A lithographic apparatus includes an illumination system, a first support structure, a second support structure, and a projection system. The illumination system is designed to receive radiation and to direct the radiation towards a patterning device that forms patterned radiation. The first support structure is designed to support the patterning device on the first support structure. The second support structure has a plurality of burls and is designed to support the substrate on the plurality of burls. A topography of a top surface of each of the plurality of burls is not substantially flat, such that a contact area between the substrate and each of the plurality of burls is reduced. The projection system is designed to receive the patterned radiation and to direct the patterned radiation towards the substrate.

Abstract: Methods and systems are described for cleaning a support such as a clamp of a chuck that holds a patterning device or a wafer in a lithographic apparatus. The method includes loading a electrostatic cleaning substrate into a lithographic apparatus. The electrostatic cleaning substrate includes at least one electrode. The method further includes bringing the electrostatic cleaning substrate near to the clamping surface to be cleaned and connecting the electrode to a voltage source. Particles present on the support are then transferred to the electrostatic cleaning substrate.

Abstract: An optical assembly and a method of making an optical assembly in which additive manufacturing techniques are used to form a support structure either directly on an optical element or on a carrier that is subsequently bonded to an optical element.

Abstract: A lithographic apparatus that includes an illumination system that conditions a radiation beam, a first stationary plate having a first surface, and a reticle stage defining, along with the first stationary plate, a first chamber. The reticle stage supports a reticle in the first chamber, and the reticle stage includes a first surface spaced apart from a second surface of the first stationary plate, thereby defining a first gap configured to suppress an amount of contamination passing from a second chamber to the first chamber. The first stationary plate is between the reticle stage and both the illumination system and a projection system configured to project a pattern imparted to the radiation beam by the patterning device onto a substrate.

Abstract: Methods and systems are described for reducing adhesion and controlling friction between a wafer and a wafer table during semiconductor photolithography wherein the tops of burls on the wafer table have a layer with a nanoscale topography.

Abstract: A substrate holder, for a lithographic apparatus, having a main body, a plurality of support elements to support a substrate and a seal unit. The seal unit may include a first seal positioned outward of and surrounding the plurality of support elements. A position of a substrate contact region of an upper surface of the first seal may be arranged at a distance from the plurality of support elements sufficient enough such that during the loading/unloading of the substrate, a force applied to the first seal by the substrate is greater than a force applied to the plurality of support elements by the substrate. A profile of the contact region, in a cross section through the seal, may have a shape which is configured such that during the loading/unloading of the substrate, the substrate contacts the seal via at least two different points of the profile.

Abstract: Disclosed is a metrology sensor apparatus comprising: an illumination system operable to illuminate a metrology mark in on a substrate with illumination radiation; an optical collection system configured to collect scattered radiation, following scattering of the illumination radiation by the metrology mark; and a wavelength dependent spatial filter for spatially filtering the scattered radiation, the wavelength dependent spatial filter having a spatial profile dependent on the wavelength of the scattered radiation. The wavelength dependent spatial filter may comprise a dichroic filter operable to substantially transmit scattered radiation within a first wavelength range and substantially block scattered radiation within a second wavelength range and at least one second filter operable to substantially block scattered radiation at least within the first wavelength range and the second wavelength range.

Abstract: A method including illuminating a product test substrate with radiation from a component, wherein the product test substrate does not have a device pattern etched therein and yields a non-zero sensitivity when illuminated, the non-zero sensitivity representing a change in an optical response characteristic of the product test substrate with respect to a change in a characteristic of the radiation; measuring at least a part of the radiation redirected by the product test substrate to determine a parameter value; and taking an action with respect to the component based on the parameter value.

Abstract: A method of dislodging contamination from a part of an apparatus used in a patterning process, the method including: providing a cleaning substrate into contact with the part of the apparatus while the part is attached to the apparatus, the cleaning substrate comprising a material configured to chemically react with the contamination; and dislodging contamination on the part of the apparatus by chemical reaction between the material and the contamination.

Abstract: A mask assembly suitable for use in a lithographic process, the mask assembly comprising a patterning device; and a pellicle frame configured to support a pellicle and mounted on the patterning device with a mount; wherein the mount is configured to suspend the pellicle frame relative to the patterning device such that there is a gap between the pellicle frame and the patterning device; and wherein the mount provides a releasably engageable attachment between the patterning device and the pellicle frame.

Abstract: A substrate provided with an anti-reflective coating where the anti-reflective coating is made up of a layer of nanostructures. The nanostructures may be formed by depositing a material such as SiO2 and then using a process such as reactive ion etching in conjunction with an inductively coupled plasma source. Other aspects of the fabrication process are also disclosed.

Abstract: A positioning system for positioning an object. The positioning system includes a stage, a balance mass and an actuator system. The stage is for holding the object. The actuator system is arranged to drive the stage in a first direction while driving the balance mass in a second direction opposite to the first direction. The stage is moveable in the first direction in a movement range. When the stage is moving in the first direction and is at an end of the movement range, the positioning system is arranged to collide the stage frontally into the balance mass.