A pattering device inspection apparatus, system and method are described. According to one aspect, an inspection method is disclosed, the method including receiving, at a multi-element detector within an inspection system, radiation scattered at a surface of an object. The method further includes measuring, with processing circuitry, an output of each element of the multi-element detector, the output corresponding to the received scattered radiation. Moreover, the method includes calibrating, with the processing circuitry, the multi-element detector by identifying an active pixel area comprising one or more elements of the multi-element detector with a measured output being above a predetermined threshold. The method also includes identifying an inactive pixel area comprising a remainder of elements of the multi-element detector. Additionally, the method includes setting the active pixel area as a default alignment setting between the multi-element detector and a light source causing the scattered radiation.

Methods of determining information about a patterning process. In a method, measurement data from a metrology process applied to each of a plurality of metrology targets on a substrate is obtained. The measurement data for each metrology target includes at least a first contribution and a second contribution. The first contribution is from a parameter of interest of a patterning process used to form the metrology target. The second contribution is from an error in the metrology process. The method further includes using the obtained measurement data from all of the plurality of metrology targets to obtain information about an error in the metrology process, and using the obtained information about the error in the metrology process to extract a value of the parameter of interest for each metrology target.

A positioning device, including: a first positioning module arranged to support and position a first substrate, a second positioning module arranged to support and position a second substrate, a first positioning field in which the first and second positioning modules can be alternatingly positioned to carry out a first processing sequence, a second positioning field in which the first and second positioning modules can be alternatingly positioned to carry out a second processing sequence, wherein when one of the first and second positioning modules is carrying out or finishing the first processing sequence, the other of the first and second positioning modules has finished the second processing sequence and is positioned closer to the one of the first and second positioning modules.

Overlay is determined for a device using signals measured from the device and a signal response to overlay determined from a plurality of calibration targets. Each calibration target has the same design as the device, but includes a known overlay shift. The calibration targets may be located in a scribe line, within a product area on the wafer, or on a separate calibration wafer. Each calibration target may have a different overlay shift, including zero overlay shift. The device may serve as a calibration target with zero overlay shift. The overlay shift may be in two orthogonal directions. The signal response to overlay may be determined based on a set of signals obtained from the calibration targets. A second set of signals may then be obtained from the device and the overlay determined based on the second set of signals and the determined signal response to overlay.

A position encoder for monitoring relative movement between a first object and a second object includes a grating that is coupled to the first object, and an image sensor assembly that is coupled to the second object. The image sensor includes a first image sensor; a second image sensor that is spaced apart from the first image sensor; an optical element that includes a first optical surface and a second optical surface that is spaced apart from the first optical surface; and an illumination system. The illumination system directs an illumination beam at the optical element to create (i) a first reference beam that is reflected by the first optical surface and directed at the first image sensor, (ii) a second reference beam that is reflected by the second optical surface and directed at the second image sensor, and (iii) a transmitted beam that is transmitted through the optical element and is directed at and impinges on the grating to create a first measurement beam that is diffracted by the grating and directed at the first image sensor, and a second measurement beam that is diffracted by the grating and directed at the second image sensor.

A self-calibrating overlay metrology system may receive device overlay data from device targets on a sample, determine preliminary device overlay measurements for the device targets including device-scale features using an overlay recipe with the device overlay data as inputs, receive assist overlay data from sets of assist targets on the sample including device-scale features, where a particular set of assist targets includes one or more target pairs formed with two overlay targets having programmed overlay offsets of a selected value with opposite signs along a particular measurement direction. The system may further determine self-calibrating assist overlay measurements for the sets of assist targets based on the assist overlay data, where the self-calibrating assist overlay measurements are linearly proportional to overlay on the sample, and generate corrected overlay measurements for the device targets by adjusting the preliminary device overlay measurements based on the self-calibrating assist overlay measurements.

Aspects of the present disclosure relate to methods and apparatus for correcting lithography systems. In one implementation, a method of operating a lithography system includes directing first light beams toward a reflective surface of a first substrate using an optical module. The method includes directing the first light beams collected through at least an objective lens toward a camera, and taking a plurality of first images of the first light beams. The method includes directing second light beams at an oblique angle toward a patterned surface of a second substrate using an illumination source disposed below the objective lens. The method includes directing the second light beams collected through at least an objective lens toward a camera, and taking a plurality of second images of the second light beams. The method includes determining a tip correction, a tilt correction, and an optimal vertical position for the optical module.

A method and apparatus for optical metrology is disclosed. There is disclosed, for example, a method involving a radiation intensity distribution for a target measured using an optical component at a gap from the target, the method including calculating a correction factor for the variation of radiation intensity of the radiation intensity distribution as a function of variation of the distance of the gap.

An imprint apparatus brings an imprint material on a substrate including a first mark into contact with a mold including a second mark and cures the imprint material, thereby forming a cured product of the imprint material on the substrate. The apparatus includes a plurality of detectors used for alignment detection, and a controller configured to obtain a plurality of pieces of relative position information by detecting a relative position between the first mark and the second mark a plurality of times using the plurality of detectors in a state in which the imprint material is cured and a positional relationship between the substrate and the mold is maintained, and to calibrate, based on the plurality of pieces of relative position information, a plurality of detection processing operations each performed using each of the plurality of detectors.

A control apparatus which generates control signal for controlling a control object, includes a first compensator configured to generate a first signal based on a control deviation of the control object, a corrector configured to generate a correction signal by correcting the control deviation in accordance with an arithmetic expression having an adjustable coefficient, a second compensator configured to generate a second signal by a neural network based on the correction signal, and an arithmetic device configured to generate the control signal based on the first signal and the second signal.