Abstract: Output beam parameters of a gas discharge laser are stabilized by maintaining a molecular fluorine component at a predetermined partial pressure using a gas supply unit and a processor. The molecular fluorine is subject to depletion within the discharge chamber. Gas injections including molecular fluorine can increase the partial pressure of molecular fluorine by a selected amount. The injections can be performed at selected intervals to maintain the constituent gas substantially at the initial partial pressure. The amount per injection and/or the interval between injections can be varied, based on factors such as driving voltage and a calculated amount of molecular fluorine in the discharge chamber. The driving voltage can be in one of multiple driving voltage ranges that are adjusted based on system aging. Within each range, gas injections and gas replacements can be performed based on, for example, total applied electrical energy or time/pulse count.

Abstract: A tunable laser system includes a gain medium and an optical resonator for generating a laser beam, and a spectral narrowing and tuning unit within the resonator. A detection and control unit controls a relative wavelength of the laser system. A wavelength calibration module calibrates the detection and control unit. The module contains more than one species each having an optical transition line within the tuning spectrum of the laser. A beam portion of the narrowed emission from the laser is directed through the wavelength calibration module and a beam portion is directed through the detection and control unit when the laser beam is scanned through the optical transition line of each of the species within the module. The detection and control unit is monitored and calibrated during the scanning.

Abstract: A method and apparatus is provided for stabilizing output beam parameters of a gas discharge laser by maintaining a molecular fluorine component of the laser gas mixture at a predetermined partial pressure using a gas supply unit and a processor. The molecular fluorine is provided at an initial partial pressure and is subject to depletion within the laser discharge chamber. Injections of gas including molecular fluorine are performed each to increase the partial pressure of molecular fluorine by a selected amount in the laser chamber preferably less than 0.2 mbar per injection, or 7% of an amount of F2 already within the laser chamber. A number of successive injections may be performed at selected intervals to maintain the constituent gas substantially at the initial partial pressure for maintaining stable output beam parameters.

Abstract: A F2 laser includes a laser tube filled with a laser gas mixture at least including molecular fluorine for generating a spectral emission including multiple closely-spaced lines in a wavelength range between 157 nm and 158 nm, including a first line centered around 157.62 nm and a second line centered around 157.52 nm, multiple electrodes within the discharge chamber connected with a power supply circuit for energizing the molecular fluorine, a laser resonator including a line selection unit for selecting one of the first and second lines of the multiple closely spaced lines and for supressing the other of the first and second lines, for generating a narrow bandwidth VUV output beam, and at least one intracavity polarizing element. The narrow bandwidth VUV output beam is polarized at least 95%, and may be 98% or more.

Abstract: A method and apparatus is provided for stabilizing output beam parameters of a gas discharge laser by maintaining a molecular fluorine component of the laser gas mixture at a predetermined partial pressure using a gas supply unit and a processor. The molecular fluorine is provided at an initial partial pressure and is subject to depletion within the laser discharge chamber. Injections of gas including molecular fluorine are performed each to increase the partial pressure of molecular fluorine by a selected amount in the laser chamber preferably less than 0.2 mbar per injection, or 7% of an amount of F2 already within the laser chamber. A number of successive injections may be performed at selected intervals to maintain the constituent gas substantially at the initial partial pressure for maintaining stable output beam parameters.

Abstract: An excimer or molecular fluorine laser system includes a wavelength calibration module permitting the wavelength of the narrow band output beam to be calibrated to a specific absolute wavelength. The module is preferably a lamp which contains at least one species including platinum with an optical transition within the emission spectrum of the laser system. Light from the lamp is preferably coincident at a spectrometer with a beam portion from the laser, and the laser beam wavelength is calibrated by simultaneous analysis at the spectrograph.

Abstract: A molecular fluorine laser includes a discharge chamber filled with a gas mixture including molecular fluorine and a buffer gas and not including a laser active rare gas, multiple electrodes within the discharge chamber defining a discharge region therebetween connected to a pulsed discharge circuit for applying discharge pulses to the electrodes for energizing the gas mixture, and a resonator including the discharge chamber for generating an oscillator laser beam at a wavelength around 157 nm and a bandwidth of less than 0.6 pm. The laser further includes a power amplifier for increasing the energy of the attenuated oscillator laser beam to a second predetermined energy for lithographic processing, a line-narrowing unit for reducing the bandwidth, a low intensity suppressor module to suppress the weaker lines of the F2-laser, and a synchronization unit to synchronize the oscillator and amplifier.

Abstract: An efficient F2 laser is provided with improvements in line selection, monitoring capabilities, alignment stabilization, performance at high repetition rates and polarization characteristics. Line selection is preferably provided by a transmission grating or a grism. The grating or grism preferably outcouples the laser beam. The line selection may be fully provided at the front optics module. A monitor grating and an array detector monitor the intensity of the selected (and unselected) lines for line selection control. An energy detector is enclosed in an inert gas purged environment at slight overpressure. A blue or green reference beam is used for F2 laser beam alignment stabilization and/or spectral monitoring of the output laser beam. The blue or green reference beam advantageously is not reflected out with a atomic fluorine red emission of the laser and is easily resolved from the red emission.

Abstract: A tunable laser system includes a gain medium and an optical resonator for generating a laser beam, and a spectral narrowing and tuning unit within the resonator. A detection and control unit controls a relative wavelength of the laser system. A wavelength calibration module calibrates the detection and control unit. The module contains more than one species each having an optical transition line within the tuning spectrum of the laser.

Abstract: An excimer or molecular fluorine laser system includes a discharge chamber filled with a laser gas mixture at least including a halogen gas and a buffer gas, a plurality of electrodes within the discharge chamber connected to a power supply circuit for energizing the gas mixture, and a resonator for generating a laser beam including a line-narrowing module on one side of the discharge chamber for reducing a bandwidth of the laser beam. The laser beam is output coupled from the resonator on the same side of the discharge chamber as the line-narrowing module and preferably after the beam is line-narrowed at the line-narrowing module. A substantially total intensity of the laser beam impinges upon a line-narrowing optical element of the line-narrowing module and is thereby line-narrowed. The resonator preferably includes at least one aperture for reducing a bandwidth of the laser beam.

Abstract: An excimer or molecular fluorine laser system includes a wavelength calibration module permitting the wavelength of the narrow band output beam to be calibrated to a specific absolute wavelength. The module is preferably a lamp which contains at least one species including platinum with an optical transition within the emission spectrum of the laser system. Light from the lamp is preferably coincident at a spectrometer with a beam portion from the laser, and the laser beam wavelength is calibrated by simultaneous analysis at the spectrograph.

Abstract: An efficient F2 laser is provided with improvements in line selection, monitoring capabilities, alignment stabilization, performance at high repetition rates and polarization characteristics. Line selection is preferably provided by a transmission grating or a grism. The grating or grism preferably outcouples the laser beam. The line selection may be fully provided at the front optics module. A monitor grating and an array detector monitor the intensity of the selected (and unselected) lines for line selection control. An energy detector is enclosed in an inert gas purged environment at slight overpressure. A blue or green reference beam is used for F2 laser beam alignment stabilization and/or spectral monitoring of the output laser beam. The blue or green reference beam advantageously is not reflected out with a atomic fluorine red emission of the laser and is easily resolved from the red emission.

Abstract: A system is provided for delivering a lithographic exposure radiation source beam of wavelength less than 200 nm from a lithographic exposure radiation source through a sealed enclosure preferably sealably connected to the lithographic exposure radiation source, and preferably to another housing, leading ultimately to a workpiece. The enclosure is preferably evacuated and back-filled with an inert gas to adequately deplete any air, water, hydrocarbons or oxygen within the enclosure. Thereafter or alternatively, an inert gas flow is established and maintained within the enclosure during operation of the lithographic exposure radiation source. Also, alternatively, the enclosure may be evacuated and no inert gas flowed. The inert gas preferably has high purity, e.g., more than 99.5% and preferably more than 99.999%, wherein the inert is preferably nitrogen or a noble gas. The enclosure is preferably made of steel and/or copper.

Abstract: A method is provided for determining the status of a gas mixture of a laser system including a gas discharge laser which generates an output beam and has a discharge chamber containing a gas mixture within which energy is supplied to the gas mixture by a power supply via application of a driving voltage to a discharge circuit. A master data set of an output parameter such as any of output beam energy, bandwidth, spectrum width, long axial beam profile, short axial beam profile, beam divergence, energy stability, energy efficiency, width of the discharge, temporal beam coherence, spatial beam coherence, spatial pulse width, amplified spontaneous emission and temporal pulse width versus an input parameter such as driving voltage is generated corresponding to an optimal gas mixture status, preferably after a new fill and typically at the factory, and alternatively following a new fill at the fab.

Abstract: A method and apparatus is provided for stabilizing output beam parameters of a gas discharge laser by maintaining a constituent gas of the laser gas mixture at a predetermined partial pressure using a gas supply unit and a processor. The constituent gas of the laser gas mixture is provided at an initial partial pressure and the constituent gas is subject to depletion within the laser discharge chamber. Injections of the constituent gas are performed each to increase the partial pressure by a selected amount in the discharge chamber preferably less than 0.2 mbar per injection. A number of successive injections is performed at selected intervals to maintain the constituent gas substantially at the initial partial pressure for maintaining stable output beam parameters. The amount per injection and/or the interval between injections may be varied based on the measured value of the driving voltage and/or a calculated amount of the constituent gas in the discharge chamber.

Abstract: A method and apparatus is provided for stabilizing output beam parameters of a gas discharge laser by maintaining a constituent gas of the laser gas mixture at a predetermined partial pressure using a gas supply unit and a processor. The constituent gas of the laser gas mixture is provided at an initial partial pressure and the constituent gas is subject to depletion within the laser discharge chamber. Injections of the constituent gas are performed each to increase the partial pressure by a selected amount in the discharge chamber preferably less than 0.2 mbar per injection. A number of successive injections is performed at selected intervals to maintain the constituent gas substantially at the initial partial pressure for maintaining stable output beam parameters. The amount per injection and/or the interval between injections may be varied based on the measured value of the driving voltage and/or a calculated amount of the constituent gas in the discharge chamber.

Abstract: A method and apparatus is provided for stabilizing output beam parameters of a gas discharge laser by maintaining a constituent gas of the laser gas mixture at a predetermined partial pressure using a gas supply unit and a processor. The constituent gas of the laser gas mixture is provided at an initial partial pressure and the constituent gas is subject to depletion within the laser discharge chamber. Injections of the constituent gas are performed each to increase the partial pressure by a selected amount in the discharge chamber preferably less than 0.2 mbar per injection. A number of successive injections is performed at selected intervals to maintain the constituent gas substantially at the initial partial pressure for maintaining stable output beam parameters. The amount per injection and/or the interval between injections may be varied based on the measured value of the driving voltage and/or a calculated amount of the constituent gas in the discharge chamber.

Abstract: A system is provided for delivering a laser beam of wavelength less than 200 nm from a laser, such as an F2 laser or ArF laser, through a sealed enclosure sealably connected to the laser, and preferably to another housing, leading ultimately to a workpiece. The enclosure is preferably evacuated and back-filled with an inert gas to adequately deplete any air, water, hydrocarbons or oxygen within the enclosure. Thereafter or alternatively, an inert gas flow is established and maintained within the enclosure during operation of the laser. The inert gas preferably has high purity, e.g., more than 99.5% and preferably more than 99.999%, wherein the inert is preferably nitrogen or a noble gas. The enclosure is preferably sealed by a window transparent to the sub-200 nm radiation for preventing contaminants generated in the enclosure from entering the housing and contaminating surfaces therein. The enclosure is preferably made of steel and/or copper, and the window is preferably made of CaF2.

Abstract: An efficient F2 laser is provided with improvements in line selection, monitoring capabilities, alignment stabilization, performance at high repetition rates and polarization characteristics. Line selection is preferably provided by a transmission grating or a grism. The grating or grism preferably outcouples the laser beam. The line selection may be fully provided at the front optics module. A monitor grating and an array detector monitor the intensity of the selected (and unselected) lines for line selection control. An energy detector is enclosed in an inert gas purged environment at slight overpressure. A blue or green reference beam is used for F2 laser beam alignment stabilization and/or spectral monitoring of the output laser beam. The blue or green reference beam advantageously is not reflected out with a atomic fluorine red emission of the laser and is easily resolved from the red emission.

Abstract: A system is provided for delivering a laser beam of wavelength less than 200 nm from a laser, such as an F2 laser or ArF laser, through a sealed enclosure sealably connected to the laser, and preferably to another housing, leading ultimately to a workpiece. The enclosure is preferably evacuated and back-filled with an inert gas to adequately deplete any air, water, hydrocarbons or oxygen within the enclosure. Thereafter or alternatively, an inert gas flow is established and maintained within the enclosure during operation of the laser. The inert gas preferably has high purity, e.g., more than 99.5% and preferably more than 99.999%, wherein the inert is preferably nitrogen or a noble gas. The enclosure is preferably sealed by a window transparent to the sub-200 nm radiation for preventing contaminants generated in the enclosure from entering the housing and contaminating surfaces therein. The enclosure is preferably made of steel and/or copper, and the window is preferably made of CaF2.