Disclosed is a method of metrology. The method comprises measuring at least one surrounding observable parameter relating to a surrounding signal contribution to a metrology signal which comprises a contribution to said metrology signal which is not attributable to at least one target being measured and determining a correction from said surrounding signal observable parameter. The correction is used to correct first measurement data relating to measurement of one or more targets using measurement radiation forming a measurement spot on one or more of said one or more targets which is larger than one of said targets.

A method of determining the position of an alignment mark on a substrate, the alignment mark having first and second segment, the method including illuminating the alignment mark with radiation, detecting radiation diffracted by the alignment mark and generating a resulting alignment signal. The alignment signal has a first component received during illumination of the first segment only, a second component received during illumination of the second segment only, and a third component received during simultaneous illumination of both segments. The positions of the segments are determined using the first component, the second component and the third component of the alignment signal.

A method of controlling a lithographic apparatus to manufacture a plurality of devices, the method including: obtaining a parameter map representing a parameter variation across a substrate by measuring the parameter at a plurality of points on the substrate; decomposing the parameter map into a plurality of components, including a first parameter map component representing parameter variations associated with the device pattern and one or more further parameter map components representing other parameter variations; deriving a scale factor, configured to correct for errors in measurement of the parameter variation, from measurements of a second parameter of a substrate; and controlling the lithographic apparatus using the parameter map and scale factor to apply a device pattern at multiple locations across the substrate.

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.

A method including obtaining a measurement result from a target on a substrate, by using a substrate measurement recipe; determining, by a hardware computer system, a parameter from the measurement result, wherein the parameter characterizes dependence of the measurement result on an optical path length of the target for incident radiation used in the substrate measurement recipe and the determining the parameter includes determining dependence of the measurement result on a relative change of wavelength of the incident radiation; and if the parameter is not within a specified range, adjusting the substrate measurement recipe.

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.

A lithographic apparatus uses a height sensor to obtain height sensor data representing a topographical variation across a substrate. The height sensor data is used to control focusing of a device pattern at multiple locations across the substrate. A controller identifies one or more first areas where height sensor data is judged to be reliable and one or more second areas where the height sensor data is judged to be less reliable. Substitute height data is calculated for the second areas using height sensor data for the first areas together with prior knowledge of expected device-specific topography. The focusing of the lithographic apparatus is controlled using a combination of the height data from the sensor and the substitute height data.

An apparatus and method for a dispenser with nozzles configured to eject lines of droplets of formable material onto a substrate in response to ejection signals. The fluid dispenser dispenses a first line of ejected droplets of formable material onto a first location on the substrate. A line camera generates camera signals that are representative of the first line of ejected droplets. The camera signals are analyzed to identify malfunctioning nozzles. The fluid dispenser dispenses a second line of ejected droplets of formable material onto a second location on the substrate that compensates for the one or more malfunctioning nozzles.

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.

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.