Abstract: A liquid immersion exposure method exposes a substrate with exposure light through liquid, and uses a projection system, a stage system having a holder that holds the substrate, a supply port via which the liquid is supplied arranged such that an upper surface of the substrate faces the supply port and that is spaced a first distance from an optical axis of the projection system, and a recovery port via which the liquid is collected arranged such that the upper surface of the substrate faces the recovery port, which is spaced a second distance greater than the first distance from the optical axis of the projection system, and that encircles the supply port. In the method, the substrate held on the holder is positioned based on a detection result of an alignment system that detects an alignment mark of the substrate not through the liquid.

Abstract: Metrology targets are formed on a substrate (W) by a lithographic process. A target (T) comprising one or more grating structures is illuminated with spatially coherent radiation under different conditions. Radiation (650) diffracted by from said target area interferes with reference radiation (652) interferes with to form an interference pattern at an image detector (623). One or more images of said interference pattern are captured. From the captured image(s) and from knowledge of the reference radiation a complex field of the collected scattered radiation at the detector. A synthetic radiometric image (814) of radiation diffracted by each grating is calculated from the complex field. From the synthetic radiometric images (814, 814?) of opposite portions of a diffractions spectrum of the grating, a measure of asymmetry in the grating is obtained. Using suitable targets, overlay and other performance parameters of the lithographic process can be calculated from the measured asymmetry.

Abstract: The present disclosure provides a focus metrology method and photolithography method and system. The focus metrology method includes recognizing at least one relevant region and at least one irrelevant region on a workpiece surface, measuring a height of the relevant region and determining a focal length for an exposure process based on the measured height of the relevant region.

Abstract: A method controls a scanning function of a lithographic apparatus. A first alignment strategy is used. A monitor wafer is exposed to determine baseline control parameters pertaining to the scanning function. The baseline control parameters are periodically retrieved from the monitor wafer. Parameter drift is determined from the baseline control parameters. Corrective action is taken based on the determination. A production wafer is exposed using a second alignment strategy, different to the first alignment strategy. The corrective action is modified so as to be substantially closer to the correction that would have been made had the second alignment strategy been used in exposing the monitor wafer.

Abstract: A lithographic apparatus includes an illumination system configured to condition a radiation beam; a support configured to support a patterning device, the patterning device being configured to impart the radiation beam with a pattern in its cross-section to form a patterned radiation beam; a substrate table configured to hold a substrate; and a projection system configured to project the patterned radiation beam onto a target portion of the substrate, wherein the radiation beam is reflected from at least one grazing incidence mirror that enhances the spectral purity of the radiation beam.