Abstract: A method for tuning a target apparatus of a patterning process. The method includes obtaining a reference performance, and measurement data of a substrate subjected to the patterning process at the target apparatus, the measurement data indicative of a performance of the target apparatus; determining a cause of a performance mismatch based on a difference between the reference performance and the performance of the target apparatus, wherein the cause includes an optical characteristic; and responsive to the cause, adjusting an optical parameter associated with an adjustable optical characteristic to reduce the performance mismatch in the optical characteristic.

Abstract: Method of determining a photodetector contribution to a measurement of apodization of a projection system of an immersion lithography apparatus, the method comprising providing a beam of radiation, illuminating an object with the beam of radiation, using the projection system to project an image of the object through a liquid layer and onto a photodetector, performing a first set of measurements of radiation intensity across a pupil plane of the projection system at a first liquid layer thickness, performing a second set of measurements of radiation intensity across the pupil plane of the projection system at a different liquid layer thickness, determining a set of intensity differences from the first set of measurements and the second set of measurements, comparing the determined set of intensity differences to an expected set of intensity difference, and using the results of the comparison to determine the photodetector contribution to a measurement of apodization.

Abstract: A method for tuning a target apparatus of a patterning process. The method includes obtaining a reference performance, and measurement data of a substrate subjected to the patterning process at the target apparatus, the measurement data indicative of a performance of the target apparatus; determining a cause of a performance mismatch based on a difference between the reference performance and the performance of the target apparatus, wherein the cause includes an optical characteristic; and responsive to the cause, adjusting an optical parameter associated with an adjustable optical characteristic to reduce the performance mismatch in the optical characteristic.

Abstract: Method of determining a photodetector contribution to a measurement of apodization of a projection system of an immersion lithography apparatus, the method comprising providing a beam of radiation, illuminating an object with the beam of radiation, using the projection system to project an image of the object through a liquid layer and onto a photodetector, performing a first set of measurements of radiation intensity across a pupil plane of the projection system at a first liquid layer thickness, performing a second set of measurements of radiation intensity across the pupil plane of the projection system at a different liquid layer thickness, determining a set of intensity differences from the first set of measurements and the second set of measurements, comparing the determined set of intensity differences to an expected set of intensity difference, and using the results of the comparison to determine the photodetector contribution to a measurement of apodization.