A lithographic apparatus includes a number of sensors for measuring positions of features on a substrate prior to applying a pattern. Each sensor includes an imaging optical system. Position measurements are extracted from pixel data supplied by an image detector in each sensor. The imaging optical system includes one or more light field modulating elements and the processor processes the pixel data as a light-field image to extract the position measurements. The data processor may derive from each light-field image a focused image of a feature on the substrate, measuring positions of several features simultaneously, even though the substrate is not at the same level below all the sensors. The processor can also include corrections to reduce depth dependency of an apparent position of the feature include a viewpoint correction. The data processor can also derive measurements of heights of features on the substrate.

A supercontinuum radiation source including a modulator being operable to modulate pump laser radiation including a train of radiation pulses to provide modulated pump laser radiation, the modulation being such to selectively provide a burst of the pulses; and a hollow-core photonic crystal fiber being operable to receive the modulated pump laser radiation and excite a working medium contained within the hollow-core photonic crystal fiber so as to generate supercontinuum radiation.

Optical components and methods of manufacture thereof. A first optical component has a hollow-core photonic crystal fiber includes internal capillaries for guiding radiation and an outer capillary sheathing the internal capillaries; and at least an output end section having a larger inner cross-sectional dimension over at least a portion of the output end section than an inner cross-sectional dimension of the outer capillary along a central portion of the hollow-core photonic crystal fiber prior to the output end section. A second optical component includes a hollow-core photonic crystal fiber and a sleeve arrangement.

The present disclosure provides an apparatus for manufacturing a semiconductor structure. The apparatus includes a stage, an optical transceiver over the stage, configured to obtain a first profile of a first surface of a substrate, an acoustic transceiver over the stage, configured to obtain a second profile of a top surface of a photo-sensitive layer over the substrate, wherein the stage is adapted to be displaced based on the first profile and the second profile.

The present invention relates to a method for determining an alignment of a photomask on a sample stage which is displaceable along at least one axis that is parallel to a chuck surface of the sample stage, and is rotatable about at least one axis that is perpendicular to the chuck surface, which method comprises the following step:

rotating the sample stage by a predefined angle and measuring a height change of the photomask during rotation at a predetermined, non-vanishing distance with respect to the rotation axis for the purpose of determining the alignment of the photomask on the sample stage.

Methods and associated apparatus for identifying contamination in a semiconductor fab. The methods include determining contamination map data for a plurality of semiconductor wafers clamped to a wafer table after being processed in the semiconductor fab. Combined contamination map data is determined based, at least in part, on a combination of the contamination map data of the plurality of semiconductor wafers. The combined contamination map data is combined to reference data. The reference data include one or more values for the combined contamination map data that are indicative of contamination in one or more tools in the semiconductor fab.

A lithographic apparatus is disclosed. The lithographic apparatus comprises a substrate table configured to support a substrate; actuators configurable to move the substrate table in a plane substantially parallel to the surface of the substrate; a projection system configured to pattern the substrate with fields aligned in a scanning exposure direction; a level sensor configured to sense a height of the substrate using a plurality of measurement spots; and a controller configured to control the actuators to generate strokes of relative movement between the substrate and the level sensor for mapping the height of the substrate, said strokes being at an angle of less than 20 degrees relative to the scanning exposure direction. Also disclosed is an associated method of mapping the height of a substrate.

A method to reduce sensitivity of a level sensor, arranged to measure a height of a substrate, to variations of a property of an optical component in the level sensor includes directing a beam of radiation toward a diffractive element and directing the beam, via an optical system, to a first reflective element at a first angle of incidence. The beam has a first polarization and a second polarization that is perpendicular to the first polarization. The first reflective element reflects the beam toward a second reflective element at a second angle of incidence causing the beam to impinge on the substrate. The first and second angles of incidence are selected to reduce variations of a ratio of intensities of the first polarization to the second polarization of the beam imparted by a property of a layer of at least one of the first and second reflective elements.

A method for monitoring a lithographic process, and associated lithographic apparatus. The method includes obtaining height variation data relating to a substrate supported by a substrate support and fitting a regression through the height variation data, the regression approximating the shape of the substrate; residual data between the height variation data and the regression is determined; and variation of the residual data is monitored over time. The residual data may be deconvolved based on known features of the substrate support.

An apparatus for measuring a height of a substrate for processing in a lithographic apparatus is disclosed. The apparatus comprises a first sensor for sensing a height of the substrate over a first area. The apparatus also comprises a second sensor for sensing a height of the substrate over a second area. The apparatus further comprises a processor adapted to normalize first data corresponding to a signal from the first sensor with a second sensor footprint to produce a first normalized height data, and to normalize second data corresponding to a signal from the second sensor with a first sensor footprint to produce a second normalized height data. The processor is adapted to determine a correction to a measured height of the substrate based on a difference between the first and second normalized height data.