Systems and methods that include providing for measuring a first topographical height of a substrate at a first coordinate on the substrate and measuring a second topographical height of the substrate at a second coordinate on the substrate are provided. The measured first and second topographical heights may be provided as a wafer map. An exposure process is then performed on the substrate using the wafer map. The exposure process can include using a first focal point when exposing the first coordinate on the substrate and using a second focal plane when exposing the second coordinate on the substrate. The first focal point is determined using the first topographical height and the second focal point is determined using the second topographical height.

A grid plate encoder based positioning system (1) for positioning of an element is provided, the positioning system (1) comprises a grid plate (2) with a grid plate surface (21); an encoder unit (3) with one or more optical sensors (31) for sensing a grid plate surface pattern (23) of the grid plate surface (21); an input (7) to receive coordinates (Xd, Yd) specifying a desired position of the element; a mapping unit (8) to compute compensated coordinate data (Xa, Ya) corresponding to estimated position data expected from the encoder unit (3) when the element is positioned at a desired position (Xd, Yd) specified by the setpoint coordinates; a feedback control unit (9) providing the compensated coordinate data (Xa, Ya) as a setpoint (Xs, Ys) to a positioning unit (12), with feedback control based on the estimated position data obtained from the encoder unit.

Additionally, a grid plate encoder based positioning method and a method for computing compensation data are provided.

Disclosed embodiments provide an electrical contact alignment strategy for leveling an array of probes, pens, tips, etc., in relationship to a substrate, for example, wherein a plurality of independent electrical circuits are formed by configuring regions of the array and substrate regions to be partially conductive and connected to opposite electrodes or vice versa.

A method for aligning a first article relative to a second article. The second article is provided with at least one flexible structure fixed to the second article at one point while the first article includes at least one surface relief marking. A detector measures the interaction between the flexible structure and surface relief marking and generates detector signals relative to that interaction to achieve alignment between the first and second articles.

For scanning electron beams and measuring overlay misalignment between an upper layer pattern and a lower layer pattern with high precision, electron beams are scanned over a region including a first pattern and a second pattern of a sample, the sample having the lower layer pattern (the first pattern) and the upper layer pattern (the second pattern) formed in a step after a step of forming the first pattern. The electron beams are scanned such that scan directions and scan sequences of the electron beams become axial symmetrical or point-symmetrical in a plurality of pattern position measurement regions defined within the scan region for the electron beams, thereby reducing measurement errors resulting from the asymmetry of electric charge.

The disclosure relates to determining information about a target structure formed on a substrate using a lithographic process. In one arrangement, a cantilever probe is provided having a cantilever arm and a probe element. The probe element extends from the cantilever arm towards the target structure. Ultrasonic waves are generated in the cantilever probe. The ultrasonic waves propagate through the probe element into the target structure and reflect back from the target structure into the probe element or into a further probe element extending from the cantilever arm. The reflected ultrasonic waves are detected and used to determine information about the target structure.

For scanning electron beams and measuring overlay misalignment between an upper layer pattern and a lower layer pattern with high precision, electron beams are scanned over a region including a first pattern and a second pattern of a sample, the sample having the lower layer pattern (the first pattern) and the upper layer pattern (the second pattern) formed in a step after a step of forming the first pattern. The electron beams are scanned such that scan directions and scan sequences of the electron beams become axial symmetrical or point-symmetrical in a plurality of pattern position measurement regions defined within the scan region for the electron beams, thereby reducing measurement errors resulting from the asymmetry of electric charge.

A method for determining a measurement setting for measuring a parameter of interest from a target structure on a substrate. The method includes: obtaining first position difference data describing a difference between a position of a first representative target structure position and a position of one or more first features relating to product structure; obtaining optical metrology data relating to optical measurements of the target structure and further relating to a plurality of different measurement settings; and determining the measurement setting from the first position difference data and the optical metrology data such that a measured feature position value obtained from an optical measurement of the target structure using the determined measurement setting is better correlated to a position of the one or more first features.