Abstract: 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).

Abstract: In some general aspects, a light beam control apparatus includes: a spectral feature actuator associated with a set of different states, each state configured to cause an optical apparatus to generate one or more pulses of a light beam at a discrete value of a spectral feature of the light beam; and a controller in communication with the spectral feature actuator. The controller includes: an actuator drive module configured to cause the spectral feature actuator to transition among the set of different states according to a control waveform; a waveform module configured to compute the control waveform for the spectral feature actuator that governs the transition among the set of discrete values; and a predictive module configured to receive one or more sensed aspects of the spectral feature actuator and instruct the waveform module to adjust the control waveform based on the received sensed aspects.

Abstract: Apparatus for and method of generating multiple laser beams using multiple laser chambers. The relative timing of the beams is controllable so they may, for example, be interleaved, may overlap, or be prevented from overlapping, or may occur in rapid sequence. The beams may have different spectral and power characteristics such as different wavelengths. Also disclosed is a system in which at least one of the multiple laser chambers is configured to generate radiation of two different wavelengths.

Abstract: A method is performed for scheduling a calibration relating to an optical device in a light source. The method can be performed by a calibration system including a calibration apparatus and a prediction controller. The method includes: receiving a property associated with the optical device while the optical device is being calibrated; calculating a current degradation metric based at least on the optical device property, the degradation metric modeling behavior of the optical device; estimating when a degradation of the optical device would exceed a threshold based on the current degradation metric; and scheduling a calibration of the optical device based at least in part on the estimate of optical device degradation.

Abstract: A radiation system for controlling pulses of radiation comprising an optical element configured to interact with the pulses of radiation to control a characteristic of the pulses of radiation, an actuator configured to actuate the optical element according to a control signal received from a controller, the control signal at least partially depending on a reference pulse repetition rate of the radiation system and, a processor configured to receive pulse information from the controller and use the pulse information to determine an adjustment to the control signal. The radiation system may be used to improve an accuracy of a lithographic apparatus operating in a multi-focal imaging mode.

Abstract: Disclosed is an electrode for a laser chamber comprising an alloy of a first metal having a first free energy of formation with fluorine greater than or equal to the free energy of formation with fluorine of copper, and a second metal having a second free energy of formation with fluorine less than the first free energy.

Abstract: A light source apparatus includes a chamber and a metal fluoride trap coupled to the chamber and configured to provide clean gas to a set of window housing apparatuses coupled to the chamber. Each window housing apparatus is configured to reduce metal fluoride dusting on an optical window and includes a window housing supporting an optical window, an aperture apparatus coupled to the window housing, and an insert disposed between the aperture apparatus and the optical window. The aperture apparatus includes a plurality of cells configured to trap metal fluoride dust flowing upstream from the chamber through the aperture apparatus toward the optical window. The insert is configured to control a first flow rate of the clean gas along the optical window and a second flow rate of the clean gas through the aperture apparatus.

Abstract: Apparatus for and method of controlling a laser system capable of generating bursts of pulses of laser radiation having multiple alternate wavelengths in which an element controlling the wavelength is pre-positioned between bursts to be between its position for generating one wavelength and its position for generating another wavelength. Also disclosed is a system that determines an optimal control waveform for the element to move between positions using quadratic programming, dynamic programing, inversion feed forward control, or iterative learning control. A data storage device such as a pre-populated lookup table or a field programmable gate array may be used to store at least one optimal control parameter for each of a plurality of repetition rates.

Abstract: A laser system's laser light energy control and resulting dose control is improved by creating and using a set of gain estimators, one for each of a set or range of laser light pulse repetition rates. When a new repetition rate is used, its corresponding gain estimator is retrieved, used to compute the voltage to fire the laser source, and updated. The resulting generated laser light thereby avoids the convergence delay inherent in prior laser systems and, further, can repeatedly do so with subsequent specified repetition rates.

Abstract: Provided is a gas control system and method for online control of a gas compartment of a radiation source. The method includes measuring a parameter of a radiation source such as an excimer laser, the parameter describing an electrical stimulation applied to the laser and/or a characteristic of radiation generated by the laser and/or an amount of a consumable in the gas compartment. A function of the parameter is compared a to a threshold and if the parameter breaches the threshold, an amount of gas is calculated based on the parameter. An instruction is provided to provide or remove the amount of gas to or from, the gas compartment. Gases may be injected or bled into the compartment during use of the radiation source thereby reducing or negating the need to take the radiation source offline to purge and refill the gas compartment.

Abstract: A deep ultraviolet (DUV) optical system includes: an optical source system including: a plurality of optical oscillators; a beam combiner; and a beam control apparatus between the optical oscillators and the beam combiner. The beam combiner is configured to receive and direct light emitted from any of the optical oscillators toward a scanner apparatus as an exposure light beam, and the beam control apparatus is configured to determine whether the beam combiner receives light from a particular one of the optical oscillators. The DUV optical lithography system also includes a control system coupled to the optical source system, the control system configured to: determine whether a condition exists in the DUV optical system, and based on a determination that the condition exists, perform a calibration action in a subset of the optical oscillators.

Abstract: Systems for maintaining light sources for semiconductor photolithography in which a module making up part of the light source is evaluated at various pulse counts to produce a binary prediction as to whether the module is sufficiently likely to operate without failure in an ensuing sequence of pulses. The binary prediction may be made by a machine learning model trained on metrics extracted from measurements taken on deinstalled modules. A group of models, each trained differently, can be made available according to a selection made by the user or according to the maintenance objectives of the user.

Abstract: A pulsed-discharge radiation source includes a gas chamber, a window, and a conduit system. The conduit system includes a refill path and a conduit. The pulsed-discharge radiation source generates radiation. The gas chamber confines a gas and contaminants produced during the generation of radiation. The window isolates the gas from an environment external to the gas chamber and allows the radiation to travel between the gas chamber and the environment. The refill path allows a replacement of the gas. The conduit circulates the gas to or from the gas chamber during the generating. The conduit system directs a flow of one of a refill gas, the gas, or the refill gas and the gas at least during a refill operation to prevent the contaminant from contacting the window, whereby the conduit system increases the usable lifetime of at least the window.

Abstract: A light source apparatus includes a gas discharge stage, a sensing apparatus, an optical arrangement, an adjustment apparatus, and a control apparatus. The gas discharge stage includes an optical amplifier including a chamber configured to hold a gas discharge medium outputting a light beam, and a set of optical elements configured to form an optical resonator around the optical amplifier. The optical arrangement is configured to image light from a plurality of distinct object planes within the gas discharge stage onto the sensing apparatus. The adjustment apparatus is in physical communication with one or more optical components within the gas discharge stage and is configured to modify at least one geometric aspect of the optical components. The control apparatus is communication with the sensing apparatus and the adjustment apparatus and is configured to provide a signal to the adjustment apparatus based on an output from the sensing apparatus.

Abstract: An apparatus includes: abeam splitter on abeam path, the beam splitter configured to receive light from a deep ultraviolet (DUV) light source; and a first plurality of reflective optical elements on the beam path. The beam splitter is configured to direct a portion of the light received from the DUV light source toward the first plurality of reflective optical elements; the first plurality of reflective optical elements is configured to rotate a divergence of the portion of the light to produce rotated light; and the beam splitter is configured to direct the rotated light and a portion of the light received from the DUV light source onto an output beam path.

Abstract: Apparatus for and methods of combining multiple, i.e., two or more laser beams to reduce even to the point of elimination a transverse gap between the two or more beams caused, for example, by a space between a coating on a surface of the mirror and the edge of the mirror, or by optic geometry, is avoided.

Abstract: A laser source includes a laser chamber configured to generate a first laser beam. The laser source further includes an optical system coupled to the laser chamber and configured to receive the first laser beam and output an output laser beam. The laser source also includes a gas purge system. According to some aspects, the gas purge system is configured to supply a nitrogen gas into the optical system at a pressure less than atmospheric pressure. According to some aspects, the gas purge system is configured to supply a helium gas into the optical system.

Abstract: An apparatus for a light source includes: an electrical insulator that defines a channel; a gasket that surrounds at least a portion of the electrical insulator; and a shield between the channel and the gasket. The channel is configured to receive an electrical conductor. The gasket includes a non-metallic material.

Abstract: Apparatus for and method of aligning optical components such as mirrors to facilitate proper beam alignment using an image integration optical system is used to integrate images from multiple optical features such as from both left mirror bank and right mirror bank to present the images simultaneously to the camera system. A fluorescent material may be used to render a beam footprint visible and the relative positions of the footprint and an alignment feature may be used to align the optical feature.

Abstract: An apparatus includes a decision module that is configured to: receive a performance metric relating to performance conditions of an optical system emitting a light beam; estimate, based on the performance metric and a predetermined learning model, an effectiveness of a proposed change to the optical system; and output a change command to the optical system if it is estimated that the proposed change to the optical system would be effective.