Enhancing target features of a pattern imaged onto a substrate. This may include adding one or more assist features to a patterning device pattern in one or more locations adjacent to one or more target features in the patterning device pattern. The one or more assist features are added based on two or more different focus positions in the substrate. This can also include shifting the patterning device pattern and/or a design layout based on the two or more different focus positions and the one or more added assist features. This may be useful for improving across slit asymmetry. Adding the one or more assist features to the pattern and shifting the pattern and/or the design layout enhances the target features by reducing a shift caused by across slit asymmetry for a slit of a multifocal lithographic imaging apparatus. This may reduce the shift across an entire imaging field.

A light source apparatus (200) includes a gas discharge stage (210) and a metal fluoride trap (300). The gas discharge stage includes an optical amplifier (206) and a set of optical elements (250, 260). The optical amplifier includes a chamber (211) configured to hold a gas discharge medium (213), the gas discharge medium outputting a light beam. The set of optical elements is configured to form an optical resonator around the optical amplifier. The metal fluoride trap is configured to trap metal fluoride dust generated from the gas discharge stage. The metal fluoride trap includes an electrostatic precipitator (320) and a packed-bed filter (400, 402, 404) disposed around the electrostatic precipitator. The packed-bed filter includes a plurality of beads configured (406, 408) to absorb metal fluoride dust (208).

Exposure apparatus includes illumination optical system and projection optical system for forming projected image with light from the illumination optical system. The illumination optical system forms, on pupil plane of the illumination optical system, light emission region including first and second regions. The projected image is composited from images including first image formed by first light from the first region and second image formed by second light from the second region. The first light and/or the second light is broadband light. Increase/decrease change in line width in the second image caused by defocus has different sign with respect to increase/decrease change in line width in the first image caused by defocus, and increase/decrease change in line width in image obtained by compositing the first image and the second image, which is caused by defocus, is decreased.

An illumination system has a microLED array 502. The microLED array 502 is imaged or placed very close to a phosphor coated glass disc 504 which upconverts the light from the microLED array into a narrow band emission. The plate has at least two different photoluminescent materials arranged to be illuminated by the microLED array and to thereby emit output light. The different photoluminescent materials have different emission spectral properties of the output light, e.g. different center wavelength and optionally different bandwidth. Illumination of different photoluminescent materials by the illumination sources is selectable, by selective activation of the microLEDs or by movement of the photoluminescent materials relative to the illumination sources, to provide different illumination of the different photoluminescent materials. This provides tunable spectral properties of the output light. Selectively configurable filters 506 are arranged to filter the output light in accordance with the selected illumination of the different photoluminescent materials.

Disclosed is an illumination arrangement for spectrally shaping a broadband illumination beam to obtain a spectrally shaped illumination beam. The illumination arrangement comprises a beam dispersing element for dispersing the broadband illumination beam and a spatial light modulator for spatially modulating the broadband illumination beam subsequent to being dispersed. The illumination arrangement further comprises at least one of a beam expanding element for expanding said broadband illumination beam in at least one direction, located between an input of the illumination arrangement and the spatial light modulator; and a lens array, each lens of which for directing a respective wavelength band of the broadband illumination beam subsequent to being dispersed onto a respective region of the spatial light modulator.

A spectral feature selection apparatus includes a dispersive optical element arranged to interact with a pulsed light beam; three or more refractive optical elements arranged in a path of the pulsed light beam between the dispersive optical element and a pulsed optical source; and one or more actuation systems, each actuation system associated with a refractive optical element and configured to rotate the associated refractive optical element to thereby adjust a spectral feature of the pulsed light beam. At least one of the actuation systems is a rapid actuation system that includes a rapid actuator configured to rotate its associated refractive optical element about a rotation axis. The rapid actuator includes a rotary stepper motor having a rotation shaft that rotates about a shaft axis that is parallel with the rotation axis of the associated refractive optical element.

A method of generating a layout pattern includes disposing a photoresist layer of a resist material on a substrate and disposing a top layer over of the photoresist layer. The top layer is transparent for extreme ultraviolet (EUV) radiation and the top layer is opaque for deep ultraviolet (DUV) radiation. The method further includes irradiating the photoresist layer with radiation generated from an EUV radiation source. The radiation passes through the top layer to expose the photoresist layer.

A system for deep ultraviolet (DUV) optical lithography includes an optical source apparatus including N optical oscillators, N being an integer number greater than or equal to two, and each of the N optical oscillators is configured to produce a pulse of light in response to an excitation signal; and a control system coupled to the optical source apparatus. The control system is configured to determine a corrected excitation signal for a first one of the N optical oscillators based on an input signal, the input signal including an energy property of a pulse of light produced by another one of the N optical oscillators.

The present disclosure is directed to systems and methods for controlling a center wavelength. In one example, a method includes estimating a center wavelength error. The method also includes determining a first actuation amount for a first actuator controlling movement a first prism based on the estimated center wavelength error. The method also includes actuating the first actuator based on the actuation amount. The method also includes determining whether the first prism is off-center. The method also includes, in response to determining that the first prism is off-center, determining a second actuation amount for the first actuator and determining a third actuation amount for a second actuator for controlling movement of a second prism. The method also includes actuating the first actuator and the second actuator based on the second and third actuation amounts, respectively. The method finds application in multi-focal imaging operations.

An optical component has a diffraction structure for diffractively influencing a direction of emergence of light of at least one wavelength incident on the optical component. The diffraction structure includes at least two diffraction substructures superimposed in at least one portion of the optical component and having first positive diffraction structures and first negative diffraction structures. A first diffraction substructure has first positive diffraction structures and first negative diffraction structures arranged to have a symmetry following a first symmetry condition. A second diffraction substructure has second positive diffraction structures and second negative diffraction structures arranged to have a second symmetry condition differing from the first symmetry condition. This can result in an optical component for which a production of a diffraction structure with a diffraction effect for different target wavelengths and/or an improved diffraction effect for one and the same target wavelength is made more flexible.