An apparatus for receiving input radiation and broadening a frequency range of the input radiation to provide broadband output radiation. The apparatus includes a chamber, a fiber, a gas generating apparatus, and a radical generating apparatus. The fiber includes a hollow core configured to guide radiation propagating through the fiber, the hollow core in fluid communication with the chamber. The gas generating apparatus is configured to provide a gas within the chamber. The radical generating apparatus is configured to provide free radicals within the chamber to reduce contaminants in the gas. The apparatus may be included in a radiation source.

An optical pulse stretcher includes a first delay optical system including a plurality of concave toroidal mirrors; and a beam splitter including a first surface and a second surface, causing a part of pulse laser light incident on the first surface to be transmitted in a first direction and output as a first beam and another part thereof to be reflected in a second direction and enter the first delay optical system, and causing a part of pulse laser light incident on the second surface from the first delay optical system to be reflected in the first direction and output as a second beam.

A pellicle having a metal oxysilicide layer. A pellicle having a molybdenum layer, a ruthenium layer and a silicon oxynitride layer, wherein the molybdenum layer is disposed between the ruthenium layer and the silicon oxynitride layer. A method of manufacturing a pellicle for a lithographic apparatus, the method including providing a metal oxysilicide layer. A lithographic assembly including a pellicle having a metal oxysilicide layer. The use of a pellicle having a metal oxysilicide layer in a lithographic apparatus.

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.

Methods and apparatus for controlling laser firing timing and hence bandwidth in a laser capable of operating at any one of multiple repetition rates.

A method includes driving, while producing a burst of pulses at a pulse repetition rate, a spectral feature adjuster among a set of discrete states at a frequency correlated with the pulse repetition rate; and in between the production of the bursts of pulses (while no pulses are being produced), driving the spectral feature adjuster according to a driving signal defined by a set of parameters. Each discrete state corresponds to a discrete value of a spectral feature. The method includes ensuring that the spectral feature adjuster is in one of the discrete states that corresponds to a discrete value of the spectral feature of the amplified light beam when a pulse in the next burst is produced by adjusting one or more of: an instruction to the lithography exposure apparatus, the driving signal to the spectral feature adjuster, and/or the instruction to the optical source.

Membranes for EUV lithography are disclosed. In one arrangement, a membrane has a stack having layers in the following order: a first capping layer including an oxide of a first metal; a base layer including a compound having a second metal and an additional element selected from the group consisting of Si, B, C and N; and a second capping layer including an oxide of a third metal, wherein the first metal is different from the second metal and the third metal is the same as or different from the first metal.

In a laser system according to a viewpoint of the present disclosure, a first amplifier amplifies first pulsed laser light outputted from a first semiconductor laser system into second pulsed laser light, a wavelength conversion system converts the second pulsed laser light in terms of wavelength into third pulsed laser light, and an excimer amplifier amplifies the third pulsed laser light. The first semiconductor laser system includes a first current controller that controls current flowing through a first semiconductor laser in such a way that first laser light outputted from the first semiconductor laser is caused to undergo chirping and a first semiconductor optical amplifier that amplifies the first laser light into pulsed light. The laser system includes a control section that controls the amount of chirping performed on the first pulsed laser light in such a way that excimer laser light having a target spectral linewidth is achieved.

A laser apparatus includes an output coupling mirror; a grating that constitutes an optical resonator together with the output coupling mirror; a laser chamber in an optical path of the optical resonator; at least one prism in an optical path between the laser chamber and the grating; a rotary stage including an actuator that rotates the prism to change an incident angle of a laser beam from the laser chamber on the grating; a wavelength measuring unit that measures a central wavelength of the laser beam from the laser chamber through the output coupling mirror; an angle sensor that detects a rotation angle of the prism; a first control unit that controls the actuator at a first operation frequency; and a second control unit that controls the actuator at a second operation frequency.

Disclosed is a metrology sensor apparatus comprising: an illumination system operable to illuminate a metrology mark in on a substrate with illumination radiation; an optical collection system configured to collect scattered radiation, following scattering of the illumination radiation by the metrology mark; and a wavelength dependent spatial filter for spatially filtering the scattered radiation, the wavelength dependent spatial filter having a spatial profile dependent on the wavelength of the scattered radiation. The wavelength dependent spatial filter may comprise a dichroic filter operable to substantially transmit scattered radiation within a first wavelength range and substantially block scattered radiation within a second wavelength range and at least one second filter operable to substantially block scattered radiation at least within the first wavelength range and the second wavelength range.