Abstract: An ultra-narrow band fluorine laser apparatus is provided in which a line width of a fluorine laser can be narrowed to about 0.2 to 0.3 pm without using any band-narrowing element such as an etalon. In an oscillator 11, a laser chamber 15 is provided in a stable type resonator constituted by an output mirror 13 and a totally reflecting mirror 14. The laser chamber 15 is filled with a laser gas at about 0.8 atm. As a result, when discharge is caused in the laser chamber 15 to cause laser oscillation, laser light L10 in a bandwidth of about 0.3 pm is provided. The power of the laser light L10 is increased by an amplifier 12. The amplifier 12 emits laser light L20 in a bandwidth of about 0.3 pm having laser energy of 10 mJ or more.

Abstract: A data recording/reproducing apparatus wherein various data to be used for maintenance are measured, and parameters required for analysis of the maintenance data are prerecorded to realize prediction of the service life of a semiconductor laser and detection of occurrence of any trouble that may be derived therefrom. In this apparatus where data are recorded in and/or reproduced from a recording medium, the internal state of the apparatus is measured, then any abnormal state in the apparatus is detected on the basis of abnormal state decision data, and the detected state is transmitted to an external information processor. The apparatus comprises a means for measuring first data relative to the apparatus; a first memory means for storing second data to make a decision as to an abnormal state of the measured first data; a means for generating third data relative to maintenance of the apparatus on the basis of the first and second data; and an output means for delivering the third data as an output.

Abstract: An injection seeded modular gas discharge laser system capable of producing high quality pulsed laser beams at pulse rates of about 4,000 Hz or greater and at pulse energies of about 5 mJ or greater. Two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. The chambers can be controlled separately permitting separate optimization of wavelength parameters in the master oscillator and optimization of pulse energy parameters in the amplifying chamber. A preferred embodiment in a F2 laser system configured as a MOPA and specifically designed for use as a light source for integrated circuit lithography. In the preferred MOPA embodiment, each chamber comprises a single tangential fan providing sufficient gas flow to permit operation at pulse rates of 4000 Hz or greater by clearing debris from the discharge region in less time than the approximately 0.25 milliseconds between pulses.

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: In a laser oscillating apparatus for exciting a laser gas in a laser tube by introducing an electromagnetic wave from a waveguide into the laser tube through a plurality of slots formed in a waveguide wall, and generating a laser beam by resonating light emitted from the laser gas, the slots are formed in a line such that their longitudinal direction is consistent with the longitudinal direction of the waveguide, and a metal wall is so formed as to surround these slots. This metal wall forms a gap as a microwave passage from the slots to a window in the laser tube wall, thereby spacing the laser tube wall apart from the slots by a predetermined distance.

Abstract: The relative timing delay between channels of a discharge circuit can be adjusted through application of appropriate control voltages. A control voltage of relatively long duration and relatively small voltage, with respect to a common system pulse, can be applied to any channel in order to adjust the relative timing delay. This control voltage can be, for example, a magnetization pre-pulse voltage applied to an indictor for a channel in order to adjust a hold-off time. A synchronization control unit and feedback loop can be used to monitor the timing, such that the syncronization control unit can apply a control voltage when a delay change exceeds a timing adjustment threshold value, and can apply a pre-ionization voltage when the delay change is less than the adjustment threshold value. Using both a control voltage and a pre-ionization voltage provides for both coarse and fine adjustment of the delay.

Abstract: A laser oscillator capable of effectively collecting and removing particulate foreign matter contained in gas laser medium flowing in a circulating path. An electric discharge section arranged in an optical resonator is incorporated into a circulating path of the gas medium including a heat exchanger and a blower. The gas laser medium flows at a high speed in the circulating path. At least one spiral-flow dust collecting mechanism is provided in the circular path downstream of the heat exchanger, and the gas laser medium discharged from the blower is supplied to the electric discharge section through the spiral-flow dust collecting mechanism. The gas laser medium containing the particulate foreign matter spirally flows around an inner pipe in a cylindrical body of the spiral-flow dust collecting mechanism.

Abstract: A lithography laser system for incorporating with a semiconductor processing system includes a discharge chamber filled with a laser gas including molecular fluorine and a buffer gas, multiple electrodes within the discharge chamber and connected with a discharge circuit for energizing the laser gas, a resonator including the discharge chamber for generating a laser beam, and a processor. The processor runs an energy control algorithm and sends a signal to the discharge circuit based on said algorithm to apply electrical pulses to the electrodes so that the laser beam exiting the laser system has a specified first energy distribution over a group of pulses. The energy control algorithm is based upon a second energy distribution previously determined of a substantially same pattern of pulses as the group of pulses having the first energy distribution.

Abstract: A buffer gas contained in a laser gas used for an ArF excimer laser mainly consists of He, and Xe is preferably added to the laser gas. Mixture piping divided by valves is disposed on piping running from a chamber to an excimer laser gas cylinder, the mixture piping and a Xe gas cylinder are connected, gas exhaust by a gas exhaust module and opening and closing of the valves are controlled by a gas controller to add a trace quantity of xenon gas to the excimer laser gas. Thus, to remedy a burst characteristic and a spike characteristic of the ultraviolet laser device by adding a trace quantity of xenon gas, the xenon gas can be supplied efficiently into the chamber without modifying existing laser gas supply equipment.

Abstract: A molecular fluorine (F2) laser system that includes a gaseous molecular fluorine gain medium contained in a laser tube, a resonant cavity, a power supply for exciting the gain medium to produce a laser beam having an ultra violet (UV) radiation output at substantially 157 nm and a red radiation output in the range of 620 to 760 nm, a discharge module connected to the laser tube for adding and withdrawing gas to the gain medium, a controller for controlling the power supply and the discharge module, and a photo diamond detector that receives a portion of the laser beam for measuring at least one optical parameter of the UV radiation such as energy, pulse energy, pulse shape, pulse width, etc. The photo diamond detector is substantially insensitive to the red radiation output that is also present in the laser beam.

Abstract: First and second radial magnetic bearings are provided at opposing ends of a rotary shaft, first and second protective bearings are arranged in the vicinity thereof, a third radial magnetic bearing is arranged on a side of a fan near a motor, and by the third radial magnetic bearing, negative spring element of the motor is corrected.

Abstract: A Master Oscillator (MO)— Power Amplifier (PA) configuration (MOPA) can be used advantageously in an excimer laser system for micro-lithography applications, where semiconductor manufacturers demand powers of 40 W or more in order to support the throughput requirements of advanced lithography scanner systems. A MOPA-based laser system can provide both high pulse energies and high spectral purity. A MOPA system can utilize a multi-pass PA, as well as a special beam path capable of reducing the amount of ASE (Amplified Spontaneous Emission) and feedback to the MO. Lithography scanner optics are primarily fused silica, such that the peak pulse power must be kept low to avoid material compaction when a MOPA system is used with lithography applications. This conflict between the demand for high average power and the low peak power requirement of the pulsed excimer laser source can be resolved by using a novel beam path to generate a sufficiently long pulse length.

Abstract: A gas supply path structure forms a fluid path for allowing a laser gas to flow into or out of a pair of fluid inlet and outlet 11a and a laser gas is controlled to a predetermined subsonic speed at a throat portion. Gas supplies for controlling the speed of the gas are connected each to the fluid inlet and to the fluid outlet of the gas supply path structure and, together with a cooling device, compose a circulation system for controlling the speed and pressure of the laser gas at the fluid inlet and/or at the fluid outlet.

Abstract: An optical element holding and extraction device is provided. The device includes an optical element, an optical element holder having a tubular gripping portion and a tubular extraction portion connected at one end to the tubular gripping portion, and a retainer that is slideably carried on the tubular extraction portion. The diameter of the tubular extraction portion is less than the tubular gripping portion. In addition, the tubular gripping portion grips the peripheral edge of the optical clement. The device may be used in a variety of gas lasers, including excimer lasers.

Abstract: The invention provides a ≧4 kHz repetition rate argon fluoride excimer laser system for producing an UV wavelength 193 nm output. The ≧4 kHz repetition rate argon fluoride excimer laser system includes an argon fluoride excimer laser chamber for producing a 193 nm discharge at a pulse repetition rate ≧4 kHz. The ≧4 kHz repetition rate argon fluoride excimer laser chamber includes magnesium fluoride crystal optic windows for outputting the 193 nm discharge as a ≧4 kHz repetition rate excimer laser 193 nm output with the magnesium fluoride crystal optic windows having a 255 nm induced absorption less than 0.08 Abs/42 mm when exposed to 5 million pulses of 193 nm light a fluence ≧40 mj/cm2/pulse and a 42 mm crystal 120 nm transmission of at least 30%.

Abstract: An excimer or molecular fluorine laser system a wavefront compensating optic within its resonator for adjusting the curvature of the wavefront of the beam for compensating wavefront distortions and thereby enhancing the spectral purity of the beam. The wavefront compensating optic may be a plate, such as a null lens. One or both surfaces of the null lens may be adjustable and/or have an adjustable curvature for controlling the wavefront distortion compensation. A multi-compartment enclosure may be included having at least one optical component of the line-narrowing unit within each compartment. An atmosphere within at least one compartment is preferably controlled for controlling the spectral purity of the beam by controlling an amount of wavefront distortion compensation. The wavefront compensating optic may be sealably disposed between adjacent compartments.

Abstract: An excimer laser gas in a laser tube 2 is excited by a microwave introduced from awaveguide 1, and electric field concentration occurs in a slit-shaped gap 3 provided in a plate member 11c, causing plasma discharge. Then the phase of plasma light is regulated and the light is resonated, to cause excimer laser light. This construction realizes plasma excitation entirely uniform along a lengthwise direction of laser light emission, and enables uniform laser light emission with minimum energy loss.

Abstract: The present invention provides an injection seeded modular gas discharge laser system capable of producing high quality pulsed laser beams at pulse rates of about 4,000 Hz or greater and at pulse energies of about 5 to 10 mJ or greater for integrated outputs of about 20 to 40 Watts or greater. Two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. The parameters chamber can be controlled separately permitting optimization of wavelength parameters in the master oscillator and optimization of pulse energy parameters in the amplifying chamber. A preferred embodiment is a F2 laser system configured as a MOPA and specifically designed for use as a light source for integrated circuit lithography. In this preferred embodiment, both of the chambers and the laser optics are mounted on a vertical optical table within a laser enclosure.

Abstract: A failure analysis system and method for multi-layer semiconductor devices, including a molecular fluorine laser system for producing a 157 nm beam and an imaging system for imaging the beam onto the semiconductor device. The laser beam etches away one or more top (passivation) layers to expose layers disposed underneath. Circuitry formed in exposed layers can then be tested.

Abstract: An excimer laser with a purged beam path capable of producing a high quality pulsed laser beam at pulse rates in excess of 2,000 Hz at pulse energies of about 5 mJ or greater. The entire purged beam path through the laser system is sealed to minimize contamination of the beam path. A preferred embodiment comprises a thermally decoupled LNP aperture element to minimize thermal distortions in the LNP. This preferred embodiment is an ArF excimer laser specifically designed as a light source for integrated circuit lithography. An improved wavemeter is provided with a special purge of a compartment exposed to the output laser beam.

Abstract: An excimer or molecular fluorine laser system includes a laser chamber filled with a gas mixture at least including a halogen-containing species and a buffer gas, and multiple electrodes with the laser chamber connected to a discharge circuit energizing the gas mixture. The laser chamber is within a laser resonator generating an output beam. The resonator includes a line-narrowing package for reducing a bandwidth of the output beam. The line-narrowing package includes a grating or grism element for use with a highly reflective (HR) and/or an anti-reflective (AR) dielectric coating. The grating may serve as a resonator reflector having a dielectric HR coating. The grating may be disposed before a HR mirror and thus have a dielectric AR or HR coating when the grating is configured in transmission or reflection mode, respectively. The grating may be used as an output coupler, and may be partially reflective with or without a coating.

Abstract: Pulse parameters of a gas discharge laser system can be optimized and controlled for precision applications such as microlithography. Important laser pulse parameters typically vary in the beginning of a pulse burst, and the directionality of the output beam typically varies throughout the burst. In order to improve the performance of the laser system, the variation at the beginning of a pulse burst can be eliminated by extending the pulse pattern and shuttering the output during periods of significant parameter variation. A fast shutter such as an acousto-optical modulator can be used to prevent output during the burst transition processes. Elements such as acousto-optical cells also can be used in combination with a fast position sensor to steer the direction of the output beam, in order to adjust for variations in the direction of the beam between pulses in a burst.

Abstract: An excimer or molecular fluorine laser system includes a laser chamber filled with a gas mixture at least including a halogen-containing species and a buffer gas, multiple electrodes, including a pair of main discharge electrodes and at least one preionization electrode, within the laser chamber and connected to a discharge circuit for energizing the gas mixture, and a resonator including a line-narrowing and/or selection module for generating a laser beam at high spectral purity.

Abstract: A final stage capacitance of a pulse compression circuit for an excimer or molecular fluorine lithography laser system is provided by a set of peaking capacitors connected through a first inductance to the electrodes and a set of sustaining capacitors connected to the electrodes through a second inductance substantially greater than the first inductance. Current pulses through the discharge are temporally extended relative to current pulses of a system having its final stage capacitance provided only by a set of peaking capacitors connected to the electrodes via the first inductance. An amplified spontaneous emission (ASE) level in the laser pulses is reduced thereby enhancing their spectral purity.

Abstract: There is provided an electric discharge gas laser comprising a housing, a rotating fan, a bearing device and a control. The housing contains a laser gas. The rotating fan is provided in the housing to circulate the gas in the housing. The bearing device magnetically supports a rotating shaft. The bearing device is provided with a sensor device comprising a sensor and a signal processor. The sensor senses the position of the rotating shaft to generate signals indicating the position of the rotating shaft. The signal processor receives and processes the signals delivered from the sensor to output processed signals. The control is separated from the bearing device and is functionally associated with the bearing device to receive the processed signal from the sensor device for controlling the bearing device on the basis of the processed signals.

Abstract: The present invention relates to a gas laser with a high-voltage electrode 12 and a ground electrode 14, which electrodes 12, 14 are disposed relative to each other so as to form a discharge gap 16 between them, and with high voltage generating means including a circuit having at least one storage capacitor and at least one secondary capacitor 18, 20, said secondary capacitor 18, 20 being disposed in the area of said high-voltage electrode 12 within a discharge chamber 32 filled with laser gas. Said secondary capacitor 18, 20 includes at least one external surface 28, 28′ oriented towards said high-voltage electrode 12 and made of a material which is inert with respect to said laser gas, which external surface 28, 28′ forms at least one boundary surface of a flow channel 26, 26′ for said laser gas.

Abstract: A helium purge for a grating based line narrowing device for minimizing thermal distortions in line narrowed lasers producing high energy laser beams at high repetition rates. Applicants have shown substantial improvement in performance with the uses of helium purge as compared to prior art nitrogen purges. In preferred embodiments a stream of helium gas is directed across the face of the grating. In other embodiments the purge gas pressure is reduced to reduce the optical effects of the hot gas layer.

Abstract: The invention provides a discharge electrodes connecting structure for a laser apparatus in which a thickness of the return plate is set to be within an optimum range, and a laser apparatus employing the same. Accordingly, a laser apparatus is provided with a laser chamber (2) sealing a laser gas, a pair of anode (5A) and cathode (5B) provided within the laser chamber in an opposing manner, generating a discharge so as to excite a laser gas flowing therebetween and oscillating a laser beam, a conductive anode base (6) holding the anode, an insulative cathode base (8) holding the cathode, and a return plate (9) electrically connecting the anode base to the laser chamber so as to supply a current to the anode. A thickness (t) of the return plate is set to be equal to or more than 100 &mgr;m and equal to or less than 500 &mgr;m, and the return plate is arranged substantially in parallel to a gas flow of the laser gas flowing between the discharge electrodes.

Abstract: An excimer or molecular fluorine laser system includes a discharge chamber filled with a gas mixture, multiple electrodes within the discharge chamber and connected to the discharge circuit for energizing the gas mixture, a resonant cavity including the discharge chamber for generating a laser beam, and an intracavity homogenizer for homogenizing an intensity profile of the laser beam generated in the resonator. The intracavity homogenizer may include each of a first bi-prism and a second bi-prism disposed at opposite ends of the resonant cavity and having the discharge chamber disposed therebetween. In this case, optical axes of the first bi-prism and the second bi-prism are each at least substantially parallel to the optical axis of the laser beam.

Abstract: The invention relates to an High Repetition Rate UV Excimer Laser which includes a source of a laser beam and one or more windows which include magnesium fluoride. Another aspect of the invention relates to an excimer laser which includes a source of a laser beam, one or more windows which include magnesium fluoride and a source for annealing the one or more windows. Another aspect of the invention relates to a method of producing a predetermined narrow width laser beam.

Abstract: An excimer or molecular fluorine laser system includes a discharge tube filled with a gas mixture, multiple electrodes within the discharge tube and connected to a discharge circuit for energizing the gas mixture, a resonator for generating a laser beam, and at least one window structure including a first window and a second window. The first window initially seals the discharge tube and transmits the beam. The second window is initially unexposed to the gas mixture. The window structure is configured such that the second window is movable into position for sealing the discharge tube and transmitting the beam when the first window becomes contaminated.

Abstract: A narrow band F2 laser system useful for integrated circuit lithography. An output beam from a first F2 laser gain medium is filtered with a pre-gain filter to produce a seed beam having a bandwidth of about 0.1 pm or less. The seed beam is amplified in a power gain stage which includes a second F2 laser gain medium. The output beam of the system is a pulsed laser beam with a full width half maximum band width of about 0.1 pm or less with pulse energy in excess of about 5 mJ. In a preferred embodiment the pre-gain filter includes a wavelength monitor which permits feedback control over the centerline wavelength so that the pre-gain filter optics can be adjusted to ensure that the desired bandwidth range is injected into the power gain stage.

Abstract: An electric discharge laser apparatus having a laser chamber containing a laser gas and two longitudinal electrodes defining a discharge region for producing electrical discharges and a tangential fan for circulating the laser gas and having blade members configured to minimize adverse effects of reflections of electric discharge generated shock waves back to the discharge region simultaneously with a subsequent discharge.

Abstract: A molecular fluorine laser system includes a discharge tube filled with a gas mixture including molecular fluorine and at least one buffer gas and having a total pressure of less than substantially 2500 mbar, multiple electrodes within the discharge tube, a pulsed discharge circuit connected to the electrodes for energizing the gas mixture, a line-selection optic for selecting one of multiple closely-spaced lines around 157 nm emitted from the discharge tube, and a laser resonator including the line-selection optic and the discharge tube for generating a beam of laser pulses having a wavelength around 157 nm at a bandwidth of less than 0.6 pm.

Abstract: A system and method for a power supply system that charges a capacitor, wherein the capacitor charge drives a pulse discharge driven system. The power supply system utilizes a main power supply and a resonant inductor and capacitor configuration to charge the capacitor to a specified, large percentage of a driving voltage that is required by the pulse system. A control module monitors the capacitor charge and disconnects the main power supply when the capacitor charge is within the specified percentage. The main power supply disconnect causes the inductor to discharge and similarly charge the capacitor in a more controlled manner. Once the control module measures the capacitor voltage at the full driving voltage, the control module commands a switch to separate the inductor from the capacitor.

Abstract: A preionization device for a gas laser includes an internal preionization electrode having a dielectric housing around it such that the preionization device is of corona type. The internal electrode connects to advantageous electrical circuitry, preferably external to the discharge chamber via a conductive feedthrough. The circuitry reduces the voltage across the dielectric tube of the preionization unit to reduce over-flashing at tube ends and oscillations due to residual energies stored in the dielectric. A semi-transparent mesh electrode between the preionization unit and the discharge area prevents field distortions and discharge instabilities.

Abstract: The present invention provides an excimer laser capable of producing a high quality pulsed laser beam at pulse rates of about 4,000 Hz at pulse energies of about 5 mJ or greater. A preferred embodiment is an ArF excimer laser specifically designed as a light source for integrated circuit lithography. An improved wavemeter with special software monitors output beam parameters and controls a very fast PZT driven tuning mirror and the pulse power charging voltage to maintain wavelength and pulse energy within desired limits. In a preferred embodiment two fan motors drive a single tangential fan which provides sufficient gas flow to clear discharge debris from the discharge region during the approximately 0.25 milliseconds between pulses.

Abstract: To provide an ArF excimer laser device capable of a pulsewidth FWHM of 20 ns or more, a pulse duration time of 50 ns or more, and a spectrum line width FWHM of 0.35 pm or less, and to provide a KrF excimer laser device and a fluorine laser device with stretched pulse widths. The ArF excimer laser device connects to the output terminal of a magnetic pulse compression circuit and has a pair of laser discharge electrodes located within the laser chamber and a peaking capacitor connected in parallel with the pair of laser discharge electrodes. The output waveform of the laser pulse has a bifurcated form with a front half peak and a later half peak and, if the peak value of the front half peak is P1 and the peak value of the later half peak is P2 and the (proportion of the pulse later half peak)=P2/(P1+P2)×100(%), then the (proportion of the pulse later half peak) is 50% or more.

Abstract: The invention provides a two-stage laser mode of photolithographic molecular fluorine laser system for matching the center wavelength of an oscillation-stage laser to the center wavelength of an amplification-stage laser, thereby oscillating a laser beam having a low spectral purity and a narrow linewidth. The laser system is of the two-stage mode comprising an oscillation-stage laser 10 and an amplification-stage mode 20. The center wavelength of a laser beam emitted out of the oscillation-stage laser 10 is compared with and substantially matched to the center wavelength of a laser beam emitted out of the amplification-stage laser 20 when the latter is oscillated by itself.

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: In an excimer laser or a molecular fluorine laser, a heating element is used which is heated to temperatures in excess of 60° C., in order to remove impurities from the laser gas.

Abstract: A grating based line narrowing device for line narrowing lasers producing high energy laser beams. Techniques are provided for minimizing adverse effects of hot gas layers present on the face of the grating. In preferred embodiments a stream of gas is directed across the face of the grating. In other embodiments the effect of the hot gas layer is reduced with the use of helium as a purge gas and in other embodiments the purge gas pressure is reduced to reduce the optical effects of the hot gas layer.

Abstract: A method of operating a laser system for increasing the lifetimes of optical components of the resonator includes the steps of configuring the laser system to initially output laser pulses at an energy in a range above a predetermined energy for industrial lithographic processing, and attenuating the energy of the output pulses to the predetermined energy. A further step includes reducing an amount of attenuation as optics of the laser resonator age to maintain the laser pulses at the predetermined energy, or reducing the amount of attenuation to produce pulses having a higher energy than the predetermined energy.

Abstract: A wavelength chirp compensation method for an excimer or molecular fluorine laser system operating in burst mode, includes pre-programming into a computer of the laser system resonator tuning optic adjustments for making the adjustments during pauses between bursts to compensate wavelength chirp at beginnings of succeeding bursts.

Abstract: A technique for bandwidth control of an electric discharge laser. Line narrowing equipment is provided having at least one piezoelectric drive and a fast bandwidth detection means and a bandwidth control having a time response of less than about 1.0 millisecond. In a preferred embodiment wavelength tuning mirror is dithered at dither rates of more than 500 dithers per second within a very narrow range of pivot angles to cause a dither in nominal wavelength values to produce a desired effective bandwidth of series of laser pulses.

Abstract: An excimer or molecular fluorine laser system is provided which emits a laser beam during operation and has a gas mixture with a gas composition initially provided within a discharge chamber. The laser system includes a discharge chamber containing a laser gas mixture at least including a halogen-containing species and a buffer gas, multiple electrodes within the discharge chamber and connected to a discharge circuit for energizing the gas mixture, a resonator for generating a laser beam, an electrostatic precipitator for having a voltage applied thereto and for receiving and precipitating contaminant particulates from a flow of the gas mixture, and a processor for monitoring the corona discharge ignition voltage of the electrostatic precipitator and for determining a status of said gas mixture based on the monitored voltage.

Abstract: The present invention relates to an excimer laser comprising a charging circuit including a parallel connection of a storage capacitor (CB) with a series connection of a reoscillation inductance (LB), a charging inductance (LL) and a firing device (Z) for firing the excimer laser, wherein the storage capacitor (CB) has at least a terminal for connecting a power supply (UL), a peaking capacitor (CP) connected in parallel with the charging inductance (LL), a discharge path including two opposed electrodes (E1, E2), connected in parallel with the peaking capacitor (CP), and a driving device for driving the firing device (Z), wherein the firing device (Z) is formed as a MOSFET array. The invention also relates to a corresponding method of operating such an excimer laser.

Abstract: An excimer or molecular fluorine laser, such as a KrF- or ArF-laser, or a molecular fluorine (F2) laser, particularly for photolithography applications, has a gas mixture including a trace amount of a gas additive. The concentration of the gas additive in the gas mixture is optimized for improving energy stability and/or the overshoot control of the laser output beam. The concentration is further determined and adjusted at new fills and/or during laser operation based on its effect on the output pulse energy in view of constraints and/or aging on the discharge circuit and/or other components of the laser system. Attenuation control is also provided for increasing the lifetimes of components of the laser system by controlling the concentration of the gas additive over time. A specific preferred concentration of xenon is more than 100 ppm for improving the energy stability and/or overshoot control.

Abstract: The present invention provides a control system for a modular high repetition rate two discharge chamber ultraviolet gas discharge laser. In preferred embodiments, the laser is a production line machine with a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber.

Abstract: The present invention provides a modular high repetition rate ultraviolet gas discharge laser light source for a production line machine. The system includes an enclosed and purged beam path with beam pointing control for delivery the laser beam to a desired location such as the entrance port of the production line machine. In preferred embodiments, the production line machine is a lithography machine and two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. This MOPA system is capable of output pulse energies approximately double the comparable single chamber laser system with greatly improved beam quality. A pulse stretcher more than doubles the output pulse length resulting in a reduction in pulse power (mJ/ns) as compared to prior art laser systems.