Abstract: A photolithography method includes instructing an optical source to produce a pulsed light beam; scanning the pulsed light beam across a wafer of a lithography exposure apparatus to expose the wafer with the pulsed light beam; during scanning of the pulsed light beam across the wafer, receiving a characteristic of the pulsed light beam at the wafer; receiving a determined value of a physical property of a wafer for a particular pulsed light beam characteristic; and based on the pulsed light beam characteristic that is received during scanning and the received determined value of the physical property, modifying a performance parameter of the pulsed light beam during scanning across the wafer.

Abstract: A metrology system is used for measuring a spectral feature of a pulsed light beam. The metrology system includes: a beam homogenizer in the path of the pulsed light beam, the beam homogenizer having an array of wavefront modification cells, with each cell having a surface area that matches a size of at least one of the spatial modes of the light beam; an optical frequency separation apparatus in the path of the pulsed light beam exiting the beam homogenizer, wherein the optical frequency separation apparatus is configured to interact with the pulsed light beam and to output a plurality of spatial components that correspond to the spectral components of the pulsed light beam; and at least one sensor that receives and senses the output spatial components.

Abstract: A spectral feature of a pulsed light beam produced by an optical source is controlled by a method. The method includes producing a pulsed light beam at a pulse repetition rate; directing the pulsed light beam toward a substrate received in a lithography exposure apparatus to expose the substrate to the pulsed light beam; modifying a pulse repetition rate of the pulsed light beam as it is exposing the substrate. The method includes determining an amount of adjustment to a spectral feature of the pulsed light beam, the adjustment amount compensating for a variation in the spectral feature of the pulsed light beam that correlates to the modification of the pulse repetition rate of the pulsed light beam. The method includes changing the spectral feature of the pulsed light beam by the determined adjustment amount as the substrate is exposed to thereby compensate for the variation in the spectral feature.

Abstract: A photolithography method includes producing, from an optical source, a pulsed light beam; and scanning the pulsed light beam across a substrate of a lithography exposure apparatus to expose the substrate with the pulsed light beam including exposing each sub-area of the substrate with the pulsed light beam. A sub-area is a portion of a total area of the substrate. For each sub-area of the substrate, a lithography performance parameter associated with the sub-area of the substrate is received; the received lithography performance parameter is analyzed, and, based on the analysis, a first spectral feature of the pulsed light beam is modified and a second spectral feature of the pulsed light beam is maintained.

Abstract: An apparatus includes a material having an optical transition profile with a known energy transition; and a detector configured to detect a characteristic associated with the interaction between the material and the testing light beam. The testing light beam is either a primary light beam produced by an optical source or a calibration light beam. The apparatus also includes a spectral analysis module placed in a path of the primary light beam; and a control system connected to the detector and to the spectral detection system. The control system is configured to determine a reference spectral profile of the primary light beam based on the detected characteristic; compare the reference spectral profile of the primary light beam with a sensed spectral profile of the primary light beam output from the spectral detection system; and based on this comparison, adjust a scale of the spectral detection system.

Abstract: A spectral feature of a pulsed light beam produced by an optical source is adjusted by receiving an instruction to change a spectral feature of the pulsed light beam from a value in a first target range to a value in a second target range; regulating a first operating characteristic of the optical source; determining an adjustment to a second actuatable apparatus of the optical source; and adjusting the second actuatable apparatus by an amount based on the determined adjustment. The first operating characteristic is regulated by adjusting a first actuatable apparatus of the optical source until it is determined that the first operating characteristic is within an acceptable range of values. The adjustment to the second actuatable apparatus is determined based at least in part on: a relationship between the adjustment of the first actuatable apparatus and a spectral feature of the light beam, and the second target range.

Abstract: Techniques for controlling an optical system include accessing a measured value of a property of a particular pulse of a pulsed light beam emitted from the optical system, the property being related to an amount of coherence of the light beam; comparing the measured value of the property of the light beam to a target value of the property; determining whether to generate a control signal based on the comparison; and if a control signal is generated based on the comparison, adjusting the amount of coherence in the light beam by modifying an aspect of the optical system based on the control signal to reduce an amount of coherence of a pulse that is subsequent to the particular pulse.

Abstract: A lithography system includes an optical source configured to emit a pulsed light beam; a lithography apparatus including an optical system, the optical system being positioned to receive the pulsed light beam from the optical source at a first side of the optical system and to emit the pulsed light beam at a second side of the optical system; and a control system coupled to the optical source and the optical lithography apparatus, the control system configured to: receive an indication of an amount of energy in the pulsed light beam at the second side of the optical system, determine an energy error, access an initial control sequence, the initial control sequence being associated with the optical source, determine a second control sequence based on the determined energy error and the initial control sequence, and apply the second control sequence to the optical source.

Abstract: 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.

Abstract: A system and method for automatically performing gas optimization after a refill in the chambers of a two chamber gas discharge laser is disclosed. The laser is fired at low power, and the gas in the amplifier laser chamber bled if necessary until the discharge voltage meets or exceeds a minimum value without dropping the pressure below a minimum value. The power output is increased to a burst pattern that approximates the expected operation of the laser, and the amplifier chamber gas bled again if necessary until the voltage and an output energy meet or exceed minimum values, or until the pressure is less than a minimum value. The gas in the master oscillator chamber is then bled if necessary until the output energy of the master oscillator meets or falls below a maximum value, again without dropping the pressure in the chamber below the minimum value. While the pressure is adjusted, bandwidth is also measured and adjusted to stay within a desired range.

Abstract: A gas discharge light source includes a gas discharge system that includes one or more gas discharge chambers. Each of the gas discharge chambers in the gas discharge system is filled with a respective gas mixture. For each gas discharge chamber, a pulsed energy is supplied to the respective gas mixture by activating its associated energy source to thereby produce a pulsed amplified light beam from the gas discharge chamber. One or more properties of the gas discharge system are determined. A gas maintenance scheme is selected from among a plurality of possible schemes based on the determined one or more properties of the gas discharge system. The selected gas maintenance scheme is applied to the gas discharge system. A gas maintenance scheme includes one or more parameters related to adding one or more supplemental gas mixtures to the gas discharge chambers of the gas discharge system.

Abstract: A system includes a first actuation module coupled to a first actuatable apparatus of an optical source, the first actuatable apparatus being altered by the first actuation module to adjust the spectral feature of the pulsed light beam; a second actuation module coupled to a second actuatable apparatus of the optical source, the second actuatable apparatus being altered by the second actuation module to adjust the spectral feature of the pulsed light beam; and a control system configured to receive an indication regarding the operating state of the first actuatable apparatus; and send a signal to the second actuation module to adjust the spectral feature of the pulsed light beam to either: prevent the first actuatable apparatus from saturating based on the operating state of the first actuatable apparatus, or desaturate the first actuatable apparatus if the first actuatable apparatus is saturated.

Abstract: A metrology system includes an optical frequency separation apparatus in the path of the pulsed light beam and configured to interact with the pulsed light beam and output a plurality of spatial components that correspond to the spectral components of the pulsed light beam; a plurality of sensing regions that receive and sense the output spatial components; and a control system connected to an output of each sensing region. The control system is configured to: measure, for each sensing region output, a property of the output spatial components from the optical frequency separation apparatus for one or more pulses; analyze the measured properties including averaging the measured properties to calculate an estimate of the spectral feature of the pulsed light beam; and determine whether the estimated spectral feature of the pulsed light beam is within an acceptable range of values of spectral features.

Abstract: A system includes a first actuatable apparatus of an optical source, the first actuatable apparatus being altered within a range of values about a target value to thereby alter a spectral feature of the light beam; a second actuatable apparatus of the optical source, the second actuatable apparatus being altered to thereby alter the spectral feature of the light beam; a metrology system including an observation system configured to output an indication of a deviation between the actual value at which the first actuatable apparatus is operating and the target value; and a control system configured to determine whether the deviation is greater than an acceptable deviation, and, if it is greater than the acceptable deviation, then send a signal to a second actuation module controlling the second actuatable apparatus to adjust the actual value at which the first actuatable apparatus is operating to be closer to the target value.

Abstract: Online calibration of laser performance as a function of the repetition rate at which the laser is operated is disclosed. The calibration can be periodic and carried out during a scheduled during a non-exposure period. Various criteria can be used to automatically select the repetition rates that result in reliable in-spec performance. The reliable values of repetition rates are then made available to the scanner as allowed values and the laser/scanner system is then permitted to use those allowed repetition rates.

Abstract: A photolithography method includes instructing an optical source to produce a pulsed light beam; scanning the pulsed light beam across a wafer of a lithography exposure apparatus to expose the wafer with the pulsed light beam; during scanning of the pulsed light beam across the wafer, receiving a characteristic of the pulsed light beam at the wafer; receiving a determined value of a physical property of a wafer for a particular pulsed light beam characteristic; and based on the pulsed light beam characteristic that is received during scanning and the received determined value of the physical property, modifying a performance parameter of the pulsed light beam during scanning across the wafer.

Abstract: A photolithography system includes an optical system, an actuation apparatus, and a control module. The optical system includes an optical source that produces a pulsed light beam traveling along a beam path; a plurality of optical components positioned between the optical source and a photolithography exposure apparatus, at least some of the plurality of optical components configured to receive the pulsed light beam and direct the pulsed light beam to the photolithography exposure apparatus; and an optical element positioned to interact with the pulsed light beam. The actuation apparatus is coupled to the optical element. The actuation apparatus is configured to adjust a physical property of the optical element based on a control signal from the control module to thereby adjust a polarization of the pulsed light beam.

Abstract: One or more operating characteristics of a light source are adjusted by estimating a plurality of extreme values of operating parameters of the light source while operating the light source under a set of extreme test conditions. For each extreme test condition, a group of pulses of energy is supplied to a first gas discharge chamber of the light source while operating the first gas discharge chamber under the extreme test condition to produce a first pulsed amplified light beam; a group of pulses of energy is supplied to a second gas discharge chamber of the light source while operating the second gas discharge chamber under the extreme test condition to produce a second pulsed amplified light beam. An extreme value of an operating parameter for the extreme test condition is measured to thereby estimate the extreme value of the operating parameter.

Abstract: A pulsed light beam emitted from an optical source is received, the pulsed light beam being associated with a temporal repetition rate; a frequency of a disturbance in the optical source is determined, the frequency being an aliased frequency that varies with the temporal repetition rate of the pulsed light beam; a correction waveform is generated based on the aliased frequency; and the disturbance in the optical source is compensated by modifying a characteristic of the pulsed light beam based on the generated correction waveform.

Abstract: A pulsed gas discharge laser operating at an output laser pulse repetition rate of greater than 4 kHz and a method of operating same is disclosed which may comprise a high voltage electrode having a longitudinal extent; a main insulator electrically insulating the high voltage electrode from a grounded gas discharge chamber; a preionizer longitudinally extending along at least a portion of the longitudinal extent of the high voltage electrode; a preionization shim integral with the electrode extending toward the preionizer. The preionizer may be formed integrally with the main insulator. The preionization shim may substantially cover the gap between the electrode and the preionizer. The apparatus and method may comprise an aerodynamic fairing attached to the high voltage electrode to present an aerodynamically smooth surface to the gas flow.