A first substrate 2002 has a calibration pattern applied to a first plurality of fields 2004 by a lithographic apparatus. Further substrates 2006, 2010 have calibration patterns applied to further pluralities of fields 2008, 2012. The different pluralities of fields have different sizes and/or shapes and/or positions. Calibration measurements are performed on the patterned substrates 2002, 2006, 2010 and used to obtain corrections for use in controlling the apparatus when applying product patterns to subsequent substrates. Measurement data representing the performance of the apparatus on fields of two or more different dimensions (fields 2004, 2008, 2012 in this example) is gathered together in a database 2013 and used to synthesize the information needed to calibrate the apparatus for a new size. Calibration data is also obtained for different scan and step directions.

Two pairs of alignment targets (one aligned, one misaligned by a bias distance) are formed on different masks to produce a first pair of conjugated interference patterns. Other pairs of alignment targets are also formed on the masks to produce a second pair of conjugated interference patterns that are inverted the first. Misalignment of the dark and light regions of the first interference patterns and the second interference patterns in both pairs of conjugated interference patterns is determined when patterns formed using the masks are overlaid. A magnification factor (of the interference pattern misalignment to the target misalignment) is calculated as a ratio of the difference of misalignment of the relatively dark and relatively light regions in the pairs of interference patterns, over twice the bias distance. The interference pattern misalignment is divided by the magnification factor to produce a self-referenced and self-calibrated target misalignment amount, which is then output.

Alignment can be monitored by positioning at least one alignment verification location per alignment frame. The alignment verification location is a coordinate within the alignment frame. A distance between each of the alignment verification locations and a closest instance of an alignment target is determined. An alignment score can be determined based on the distance. The alignment score can include a number of the alignment frames between the alignment verification location and the alignment target. If the alignment score is below a threshold, then alignment setup can be performed.

A method includes the following operations. A reference image of a mask having a plurality of mapping marks is acquired. A lithography exposing process is performed by a scanner with the mask to a photoresist layer which is formed on a substrate. Performing the lithography exposing process includes mapping a real-time image of the mask with the reference image of the mask.

A lithographic apparatus includes a patterning device support to support a patterning device, the patterning device system including a moveable structure movably arranged relative to an object, a patterning device holder movably arranged relative to the movable structure to hold the patterning device, an actuator to move the movable structure relative to the object, and an ultra short stroke actuator to move the patterning device holder with respect to the movable structure; a substrate support to hold a substrate; a projection system to project a patterned radiation beam onto a target portion of the substrate; a transmission image sensor for measuring a position of the patterned radiation beam downstream of the projection system; and a calibrator for determining a relationship between magnitude of an applied control signal to the ultra short stroke actuator and resulting change in position of the patterned radiation beam and/or patterning device holder and/or patterning device.

A lithographic apparatus having a substrate table, a projection system, an encoder system, a measurement frame and a measurement system. The substrate table has a holding surface for holding a substrate. The projection system is for projecting an image on the substrate. The encoder system is for providing a signal representative of a position of the substrate table. The measurement system is for measuring a property of the lithographic apparatus. The holding surface is along a plane. The projection system is at a first side of the plane. The measurement frame is arranged to support at least part of the encoder system and at least part of the measurement system at a second side of the plane different from the first side.

An angle adjustment tool, an angle adjustment system for a liquid crystal panel and a corresponding line defect analysis method are disclosed. The angle adjustment tool includes: a base; a first toothed member and a second toothed member; a rotating scale; and an angle indicator. The first toothed member includes a first toothed portion. A first end of the second toothed member has a second toothed portion and engages with the first toothed portion of the first toothed member, and a second end of the second toothed member is connected to the rotating scale; the second toothed member is pivotable about a central pivot axis of the second toothed portion. A pitch circle diameter of the second toothed portion is n times a pitch circle diameter of the first toothed portion, where n is a positive integer greater than or equal to 2.

A method includes the following operations. A reference image of a mask having a plurality of mapping marks is acquired. A lithography exposing process is performed by a scanner with the mask to a photoresist layer which is formed on a substrate. Performing the lithography exposing process includes mapping a real-time image of the mask with the reference image of the mask.

A first substrate (2002) has a calibration pattern applied to a first plurality of fields (2004) by a lithographic apparatus. Further substrates (2006, 2010) have calibration patterns applied to further pluralities of fields (2008, 2012). The different pluralities of fields have different sizes and/or shapes and/or positions. Calibration measurements are performed on the patterned substrates (2002, 2006, 2010) and used to obtain corrections for use in controlling the apparatus when applying product patterns to subsequent substrates. Measurement data representing the performance of the apparatus on fields of two or more different dimensions (2004, 2008, 2012) is gathered together in a database (2013) and used to synthesize the information needed to calibrate the apparatus for a new size. Calibration data is also obtained for different scan and step directions.

A method for determining one or more optimized values of an operational parameter of a sensor system configured for measuring a property of a substrate is disclosed the method comprising: determining a quality parameter for a plurality of substrates; determining measurement parameters for the plurality of substrates obtained using the sensor system for a plurality of values of the operational parameter; comparing a substrate to substrate variation of the quality parameter and a substrate to substrate variation of a mapping of the measurement parameters; and determining the one or more optimized values of the operational parameter based on the comparing.