An illumination correction apparatus for correcting a radiation beam incident on a reticle from an exposure apparatus includes a plurality of fingers each having a surface facing an incident direction of the radiation beam, the plurality of fingers being arranged in a first direction to be adjacent to a path of the radiation beam, and configured to adjust an amount of the incident radiation beam by moving in a second direction, intersecting the first direction, a controller connected to the plurality of fingers and configured to control movement of the plurality of fingers such that an intensity of the radiation beam has uniformity in the first direction, at least one optical sensor on the surface of at least one finger of the plurality of fingers, and a measurement unit configured to measure, based on an output of the at least one optical sensor, the intensity of the radiation beam.

A device for measuring reference points in real time during lithographic printing includes a light source providing an exposure beam; a light modulator modulating the exposure beam according to an exposure pattern; a measurement system configured to measure a position of a number of alignment marks previously arranged on a substrate; and an exposure optical system comprising a control unit. The exposure optical system delivers the modulated exposure beam as an image provided by the light modulator onto the substrate. The exposure system control unit is configured to calculate the orientation of the substrate based on the position of the alignment marks and control the delivering of the modulated exposure beam relative to the calculated orientation of the substrate.

Disclosed is a lithography process on a sample with at least one emitter, the process including: putting at least one layer of resist above the sample; exciting one selected emitter with light through the at least one layer of resist; detecting light emitted by the excited selected emitter and determining a position of the selected emitter; and curing with a light beam a part of the at least one layer of resist above the position of the selected emitter, the light beam being a shaped light beam having a cross-section, this cross-section having a central part, an intermediate part surrounding the central part and a border part surrounding the intermediate part, the intensity of the shaped light beam on the at least one layer of resist reaching a maximum at the intermediate part.

An evaluation method for evaluating an aberration of a projection optical system in an exposure apparatus is provided. A first prediction coefficient of a first prediction formula for an aberration that is symmetrical with respect to an optical axis of the projection optical system is obtained, and a second prediction coefficient of a second prediction formula for an aberration that is asymmetrical with respect to the optical axis of the projection optical system is obtained. The aberration of the projection optical system is evaluated using the first prediction coefficient in a case where the shape of the illuminated region is determined as symmetrical with respect to the optical axis, and the aberration of the projection optical system is evaluated using the first and the second prediction coefficients in a case where the shape of the illuminated region is asymmetrical with respect to the optical axis.

A scatterometer performs diffraction based measurements of one or more parameters of a target structure. To make two-color measurements in parallel, the structure is illuminated simultaneously with first radiation (302) having a first wavelength and a first angular distribution and with second radiation (304) having a second wavelength and a second angular distribution. The collection path (CP) includes a segmented wavelength-selective filter (21, 310) arranged to transmit wanted higher order portions of the diffracted first radiation (302X, 302Y) and of the diffracted second radiation (304X, 304Y), while simultaneously blocking zero order portions (302, 304) of both the first radiation and second radiation. The illumination path (IP) in one embodiment includes a matching segmented wavelength-selective filter (13, 300), oriented such that a zero order ray passing through the illumination optical system and the collection optical system will be blocked by one of said filters or the other, depending on its wavelength.

In corner sections of first to fourth quadrants whose origin point is a center of an upper surface of a stage, three each of two-dimensional heads are provided. The three each of two-dimensional heads include one first head and two second heads. The stage is driven, while measuring a position of the stage using three first heads that face a two-dimensional grating of a scale plate provided above the stage from the four first heads, and during the driving, difference data of measurement values of the two second heads with respect to the first head in a measurement direction are taken in for head groups to which the three first heads belong, respectively, and using the difference data, grid errors are calibrated.

An inspection apparatus (140) measures asymmetry or other property of target structures (T) formed by a lithographic process on a substrate. For a given set of illumination conditions, accuracy of said measurement is influenced strongly by process variations across the substrate and/or between substrates. The apparatus is arranged to collect radiation scattered by a plurality of structures under two or more variants of said illumination conditions (p1, p1, p1+; 1, 1, 1+). A processing system (PU) is arranged to derive the measurement of said property using radiation collected under a different selection or combination of said variants for different ones of said structures. The variants may be for example in wavelength, or in angular distribution, or in any characteristic of the illumination conditions. Selection and/or combination of variants is made with reference to a signal quality (302, Q, A) observed in the different variants.

In corner sections of first to fourth quadrants whose origin point is a center of an upper surface of a stage, three each of two-dimensional heads are provided. The three each of two-dimensional heads include one first head and two second heads. The stage is driven, while measuring a position of the stage using three first heads that face a two-dimensional grating of a scale plate provided above the stage from the four first heads, and during the driving, difference data of measurement values of the two second heads with respect to the first head in a measurement direction are taken in for head groups to which the three first heads belong, respectively, and using the difference data, grid errors are calibrated.

A method including: obtaining a measurement of a metrology target on a substrate processed using a patterning process, the measurement having been obtained using measurement radiation; and deriving a parameter of interest of the patterning process from the measurement, wherein the parameter of interest is corrected by a stack difference parameter, the stack difference parameter representing an un-designed difference in physical configuration between adjacent periodic structures of the target or between the metrology target and another adjacent target on the substrate.

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.