A reflective optical element (17), in particular for an illumination optical unit of a projection exposure apparatus includes: a structured surface (25a) that preferably forms a grating structure (29), and a reflective coating (36) that is applied to the structured surface (25a). The reflective coating (36) covers the structured surface (25a) discontinuously, and the reflective optical element (17) has at least one protective layer (37) that covers the structured surface (25a) continuously. Also disclosed are an illumination optical unit (4) for a projection exposure apparatus (1) including at least one reflective optical element (17) of this type, to a projection exposure apparatus (1) including an illumination optical unit (4) of this type, and to a method for producing a protective layer (37) on a reflective optical element (17) of this type.

A laser device includes a first actuator configured to adjust an oscillation wavelength of pulse laser light; a second actuator configured to adjust a spectral line width of the pulse laser light; and a processor configured to determine a target spectral line width by reading data specifying a number of irradiation pulses of the pulse laser light with which one location of an irradiation receiving object is irradiated and a difference between a shortest wavelength and a longest wavelength, control the second actuator based on the target spectral line width, and control the first actuator so that the oscillation wavelength periodically changes every number of the irradiation pulses between the shortest wavelength and the longest wavelength.

Provided are a device (4) and a method for online measuring a spectrum for a laser device. The device (4) for online measuring a spectrum for a laser device includes: a first optical path assembly (G1) and a second optical path assembly (G2), and the second optical path assembly (G2) and the first optical path assembly (G1) constitute a measurement optical path. The second optical path assembly (G2) includes: an FP etalon (15) and a grating (18). The homogenized laser beam passes through the FP etalon (15) to generate an interference fringe. The grating (18) is arranged after the FP etalon (15), or is arranged before the FP etalon (15) in the measurement optical path, and is configured to disperse the laser beam passing through the FP etalon (15). A high precision measurement in a wide range for a central wavelength of a laser beam and an accurate measurement for spectral parameters of a corresponding FWHM and E95 are achieved through an arrangement of the FP etalon and the grating “in series” in the measurement optical path. There is no moving element in the measurement optical path, the structure is simple and compact, the measurement precision is high, and the stability is high. The corresponding measurement algorithm is simple and efficient, and has an extremely high scientific research or commercial application value.

An alignment system having long term stability in illumination center wavelength is discussed. The alignment system includes a tunable radiation source and a feedback control system. The tunable radiation source includes a light source configured to provide a broadband radiation beam and a tunable multi-passband filter configured to filter the broadband radiation beam into narrow band radiation beam having a center wavelength value. The feedback control system is configured to measure the center wavelength value of the narrow band radiation beam and compare the measured center wavelength value with a desired center wavelength value. The feedback control system is further configured to generate a control signal based on the comparison in response to a difference being present between the measured center wavelength value and the desired center wavelength value and tune the tunable filter based on the control signal to eliminate or substantially reduce the difference.

The present disclosure provides an interference filter, a lithography system incorporating an interference filter, and a method of fabricating an interference filter. The interference filter includes a transparent substrate having a front surface and a back surface, a plurality of alternating material layers formed over the front surface of the transparent substrate that form a bandpass filter, and an anti-reflective structure formed over the back surface of the transparent substrate. The alternating material layers alternate between a relatively high refractive index material and a relatively low refractive index material.

A method includes producing a pulsed light beam; directing the pulsed light beam toward a substrate mounted to a stage of a lithography exposure apparatus; scanning a pulsed light beam and the substrate relative to each other, including projecting the pulsed light beam onto each sub-area of the substrate and moving one or more of the pulsed light beam and the substrate relative to each other; determining a value of a vibration of the stage for each sub-area of a substrate; for each sub-area of the substrate, determining an amount of adjustment to a bandwidth of the pulsed light beam, the adjustment amount compensating for a variation in the stage vibration so as to maintain a focus blur within a predetermined range of values across the substrate; and changing the bandwidth of the pulsed light beam by the determined adjustment amount to thereby compensate for the stage vibration variations.

An optical element for a lithographic apparatus, the optical element including an anchor layer selected to support a top layer having self-terminating growth in an operating lithographic apparatus or plasma containing environment. Also described is a method of manufacturing an optical element, the method including depositing a top layer on anchor layer via exposure to plasma, preferably electromagnetically induced plasma. Lithographic apparatuses including such optical elements are also described.

An apparatus (100) for receiving input radiation (108) and broadening a frequency range of the input radiation so as to provide broadband output radiation (110). The apparatus comprises a fiber (102), wherein the fiber (102) may comprise a hollow core (104) for guiding radiation propagating through the fiber (102). The apparatus (100) further comprises an apparatus for providing a gas mixture (106) within the hollow core (104). The gas mixture (106) comprises a hydrogen component, and a working component, wherein the working component is for broadening a frequency range of a received input radiation (108) so as to provide the broadband output radiation (110). The apparatus may be included in a radiation source.

An exposure apparatus may include a laser light source capable of varying a wavelength of a laser beam that is emitted from the laser light source, a mask on which a pattern is formed, the pattern being configured to generate diffracted light by being irradiated with the laser beam, and a controller configured to control, in accordance with a distance between the mask and a substrate, the wavelength of the laser beam that is emitted from the laser light source, wherein the mask is irradiated with the laser beam emitted from the laser light source to perform proximity exposure on a surface of the substrate.

A method of manufacturing a semiconductor device includes irradiating a first photoresist layer via a light source, measuring a first exposure intensity of the first photoresist layer, irradiating a second photoresist layer via the light source, measuring a second exposure intensity of the second photoresist layer, subtracting the second exposure intensity from the first exposure intensity, and subsequent to the subtracting, exposing a third photoresist layer formed on a semiconductor substrate by using the light source, wherein an out-of-band (OoB) extreme ultraviolet (EUV) light eliminating layer is formed on the second photoresist layer.