A metrology system includes a light beam metrology apparatus configured to sense one or more aspects of an amplified light beam and to make adjustments to the amplified light beam based on the sensed one or more aspects; a target metrology apparatus configured to measure one or more properties of a modified target after a target has interacted with the amplified light beam, and to determine a moment when the modified target achieves a reference calibration state; and a control apparatus configured to: receive the reference calibration state and the moment at which the reference calibration state is achieved from the target metrology apparatus; determine a light beam calibration state of the amplified light beam based on the received reference calibration state and the moment at which the reference calibration state is achieved; and provide the light beam calibration state to the light beam metrology apparatus.

An insert for a source chamber of an EUV radiation source has a pressure stage and, spaced apart from it, a stop.

An optical source for a photolithography tool includes a source configured to emit a first beam of light and a second beam of light, the first beam of light having a first wavelength, and the second beam of light having a second wavelength, the first and second wavelengths being different; an amplifier configured to amplify the first beam of light and the second beam of light to produce, respectively, a first amplified light beam and a second amplified light beam; and an optical isolator between the source and the amplifier, the optical isolator including: a plurality of dichroic optical elements, and an optical modulator between two of the dichroic optical elements.

An EUV light source module includes an EUV vessel, a collector disposed in the EUV vessel, a droplet generator, a droplet catcher, and a droplet collecting system. The droplet generator is coupled to the EUV vessel and configured to provide a plurality of target droplets into the EUV vessel. The droplet catcher is coupled to the EUV vessel and configured to catch at least a target droplet from the EUV vessel. The droplet colleting system is coupled to the droplet catcher. The droplet collecting system includes a connecting port coupled to the droplet catcher, and a thermal insulating device surrounding the droplet catcher. The droplet generator and the droplet catcher are disposed at opposite locations in the EUV vessel.

A radiation source for an EUV lithography apparatus is disclosed. The radiation source comprises a chamber comprising a plasma formation region, a radiation collector arranged in the chamber and configured to collect radiation emitted at the plasma formation region and to direct the collected radiation towards an intermediate focus region, and a radiation conduit disposed between the radiation collector and the intermediate focus region. The radiation conduit comprises at least one outlet on an inner surface of a wall of the radiation conduit for directing a protective gas flow, and at least one guide portion extending from the inner surface of the wall of the radiation conduit and configured to redirect the protective gas flow. Also disclosed is a method of reducing debris and/or vapor deposition in the radiation conduit by providing a protective gas flow to the at least one outlet of the radiation conduit.

A high harmonic radiation source and associated method of generating high harmonic radiation is disclosed. The high harmonic radiation source is configured to condition a gas medium by irradiating the gas medium with a pre-pulse of radiation, thereby generating a plasma comprising a pre-pulse plasma distribution; and irradiate the gas medium with a main pulse of radiation to generate said high harmonic radiation. The conditioning step is such that the plasma comprising a pre-pulse plasma distribution acts to configure a wavefront of said main pulse to improve one or both of: the efficiency of the high harmonic generation process and the beam quality of the high harmonic radiation. The high harmonic radiation source further may comprise a beam shaping device configured to shape said customized pre-pulse prior to said conditioning.

Methods and systems for characterizing dimensions and material properties of semiconductor devices by transmission small angle x-ray scatterometry (TSAXS) systems having relatively small tool footprint are described herein. The methods and systems described herein enable Q space resolution adequate for metrology of semiconductor structures with reduced optical path length. In general, the x-ray beam is focused closer to the wafer surface for relatively small targets and closer to the detector for relatively large targets. In some embodiments, a high resolution detector with small point spread function (PSF) is employed to mitigate detector PSF limits on achievable Q resolution. In some embodiments, the detector locates an incident photon with sub-pixel accuracy by determining the centroid of a cloud of electrons stimulated by the photon conversion event. In some embodiments, the detector resolves one or more x-ray photon energies in addition to location of incidence.

Laser plasma optical device comprising a laser system for outputting driving light pulses and signal light pulses, a vacuum target chamber, a gas target generating device for generating gas and forming a required plasma channel target through high voltage capillary discharge ionization (or through laser picosecond pre-pulse ablation) of gas, and a focusing element. The driving light pulse is focused on the generated plasma channel target through the focusing element to generate a density-modulated plasma wake; and after a predetermined delay time T, the signal light pulse is focused onto a leading edge region of a second plasma density cavitation bubble of the plasma wake through the focusing element, so that the frequency of the signal light pulse is red-shifted to generate an ultra-intense near-single-cycle mid-infrared pulse.

A beam delivery system according to an aspect of the present disclosure is used for an extreme ultraviolet light generation apparatus and includes a propagation mirror disposed on an optical path between a laser apparatus and a condensation optical system and configured to change the propagation direction of a pulse laser beam, and a curvature mirror disposed on an optical path between the propagation mirror and the condensation optical system and having a concave reflective surface configured to convert the pulse laser beam to be incident on the condensation optical system into a convergent beam. The curvature mirror has a focal length selected so that the beam spread angle of the pulse laser beam from the curvature mirror is constant irrespective of thermal deformation of the propagation mirror or constant with change in a predetermined allowable range irrespective of thermal deformation of the propagation mirror.

A method of controlling a droplet illumination module/droplet detection module system of an extreme ultraviolet (EUV) radiation source includes irradiating a target droplet with light from a droplet illumination module and detecting light reflected and/or scattered by the target droplet. The method includes determining whether an intensity of the detected light is within an acceptable range. In response to determining that the intensity of the detected light is not within the acceptable range, a parameter of the droplet illumination module is automatically adjusted to set the intensity of the detected light within the acceptable range.