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 method for producing molecular Iodine for introduction into the laser cavity of a Chemical-Oxygen-Iodine-Laser (COIL) includes the step of preparing a solid mixture that contains a primary component and an additive component. The solid mixture is formulated to generate a gas having a high concentration of molecular Iodine when ignited. The primary component of the mixture is composed of oxidizer and fuel at a substantially stoichiometric ratio and includes at least one Iodine compound. The additive component is provided to cool the relatively high temperature gas that is created during combustion of the primary component. The result is a gas at a relatively low temperature in which most of the Iodine is present as molecular Iodine. The additive component is preferably an Iodine compound that either absorbs heat during decomposition such as Iodine Pentoxide (I2O5) or an Iodine compound that absorbs heat during sublimation such as solid Iodine.

Abstract: A system for collecting, reprocessing, and recycling chemical species used in the operation of a chemical oxygen-iodine laser system, especially a space-based system, is described.

Abstract: A gas discharge laser having an elongated cathode and an elongated anode with a porous insulating layer covering the anode discharge surface. A pulse power system provides electrical pulses at rates of at least 1 KHz. A blower circulates laser gas between the electrodes at speeds of at least 5 m/s and a heat exchanger is provided to remove heat produced by the blower and the discharges. In preferred embodiments at least a portion of the anode is comprised of lead, and fluorine ion sputtering of the anode surface creates the insulating layer (over the discharge surface of the anode) comprised in large part of lead fluoride. In a particular preferred embodiment the anode is fabricated in two parts, a first part having the general shape of a prior art anode with a trench shaped cavity at the top and a second part comprised of lead rich brass and disposed in the trench shape cavity.

Abstract: Methods and apparatus are provided for cleaning and passivating laser discharge chambers with plasmas. In one embodiment, an oxygen based plasma is formed in a plasma source external to the laser discharge chamber by applying a radiofrequency signal to oxygen containing gases. The oxygen based plasma is drawn into the laser discharge chamber, where it reacts with contaminants and cleans internal surfaces. After cleaning, a fluorine based plasma is formed in the plasma source and drawn into the laser discharge chamber to passivate internal surfaces. In another embodiment, cleaning with the oxygen based plasma is not used since some level of cleaning is accomplished with the fluorine based plasma. In another embodiment, oxygen based plasmas and fluorine based plasmas are formed in the laser discharge chamber by applying a radiofrequency signal to a laser discharge chamber electrode.

Abstract: An on-demand system for generating Iodine gas that is substantially free of contaminants such as water, Carbon Monoxide and Carbon Dioxide includes a solid mixture of oxidizer and fuel having at least one Iodine compound. An ignitor squib is provided to ignite the mixture and thereby generate a contaminant free Iodine gas. Preferably, Iodine Pentoxide (I2O5) is used as the oxidizer and a metal such as Zinc, Tin, Calcium, Magnesium, Aluminum, Silica, Sodium, Potassium, Lithium, Boron, Beryllium, Sodium Azide or Iron is used as the fuel. With this composition, the solid mixture is substantially free of Hydrogen and Carbon compounds and the corresponding combustion gas is free of water, Carbon Monoxide and Carbon Dioxide. The mixture is disposed within a permeable jacket to capture non-gas reaction products generated during combustion such as solid and liquid metal oxides while allowing Iodine gas to pass through the permeable jacket.

Abstract: An integrated dual source recycling system for a chemical oxygen-iodine laser system is described. The recycling system primarily includes: (1) a first collection system for collecting an amount of spent basic hydrogen peroxide comprised of spent aqueous potassium chloride; and (2) a second collection system for collecting an amount of the spent laser exhaust gas. Several processing systems are also employed to convert the spent aqueous potassium chloride and the spent laser exhaust gas into hydrogen peroxide and potassium hydroxide which are mixed together to form fresh basic hydrogen peroxide. Additionally, the spent laser exhaust gas is recycled back into molecular nitrogen, molecular iodine, molecular oxygen, and molecular chlorine.

Abstract: A gas drawing/refilling and sealing structure for a laser gas storage container of the present invention includes a sealed container and a blocking member, wherein the body of the container is provided with a gas passage having a gas inlet end and a blocking end. The gas passage is further provided with a communicating section to make connection of the gas passage to the container. The blocking member is mounted on the blocking end, gas is drawn out of or injected into the container via the gas inlet end when the gas inlet end is opened; the gas is cut off when the gas inlet end is closed, and the container is sealed at the same time. Thereby, manufacturing and test of the laser equipment can be more convenient, and the superiority of products can be increased.

Abstract: A method of operating a laser is disclosed. Components of the laser are located in an enclosure, which may contain contaminants including water vapor and organic vapor released by the optical components, mounts of the optical components, or the enclosure itself. The enclosure may also contain suspended particulate matter and ozone. In order to reduce the level of these contaminants, a purging system extracts gas from the enclosure and passes the gas through a catalyst to decompose the ozone, a desiccant, an organic vapor trapping material, and a particulate matter filter, then returns the extracted gas to the enclosure. Decomposing ozone is particularly important if the laser generates radiation at a wavelength less than 250 nm.

Abstract: A method of operating a laser is disclosed. Components of the laser are located in an enclosure, which may contain contaminants including water vapor and organic vapor released by the optical components, mounts of the optical components, or the enclosure itself. The enclosure may also contain suspended particulate matter and ozone. In order to reduce the level of these contaminants, a purging system extracts gas from the enclosure and passes the gas through a catalyst to decompose the ozone, a desiccant, an organic vapor trapping material, and a particulate matter filter, then returns the extracted gas to the enclosure. Decomposing ozone is particularly important if the laser generates radiation at a wavelength less than 250 nm.

Abstract: A sealed exhaust chemical oxygen-iodine laser (SECOIL) employing a sealed exhaust system (SES) is described. The SES is capable of selectively condensing and cryosorbing various chemical species contained in the laser-exhaust gas. Additionally, a condensable diluent is employed. The SES is configured so that the diluent and other condensables can be removed in a first stage with a high temperature condensing bed, while the oxygen can then be removed in a second stage in a low temperature sorbing bed. The result is a reduction in the weight, volume, and power consumption of the SECOIL system, especially the SES component thereof.

Abstract: A system for supplying Iodine gas to a laser cavity includes a cartridge for generating Iodine gas and delivery piping for transporting Iodine gas from the cartridge to the laser cavity. The cartridge includes a hollow, cylindrical casing having an open end. The casing contains a solid preheat material, a solid mixture containing Iodine, and a purge material. An ignitor squib is disposed in the casing near the open end to initiate a burn front. The burn front travels through the preheat material to generate hot gas for preheating the delivery piping, preventing Iodine gas condensation in the piping. Next, the burn front travels through the mixture containing Iodine to generate Iodine gas which flows through the preheated delivery piping to the laser cavity. The burn front then passes through the purge material generating a purge gas to remove any traces of corrosive Iodine gas from the delivery piping.

Abstract: A supplying method and a supplying apparatus for supplying fluorine gas, in which when a fluorine-occluding substance is used for the fluorine gas-generating means, a necessary amount of fluorine gas can be stably and swiftly supplied to have a uniform concentration to &a chamber of an excimer laser device or the like even at running, to say nothing of the gas exchange time. In a fluorine gas-generating means, fluorine gas is generated at the use point by controlling a fluorine-occluding substance to a predetermined temperature, the fluorine gas is introduced into a mixing container, a diluting gas is introduced into the mixing container to mix it with the fluorine gas to prepare a fluorine mixed gas having a predetermined pressure and a predetermined fluorine gas concentration, and the fluorine mixed gas reserved in the mixing container is supplied to a use side such as chamber, using the pressure difference.

Abstract: A gas laser and a dedusting unit thereof are provided. The gas laser comprises a tube containing a gas mixture including a laser gas and preferably a buffer gas. The tube preferably comprises a cylindrical inner wall. A discharge unit is inserted into the tube and has two elongated electrodes defining an electrical gas discharge gap therebetween for providing an electric gas discharge between said electrodes to generate laser light. A circulation means is included in the tube for generating a gas flow within the tube that passes through the discharge gap. A dedusting unit is mounted along the inner cylindrical wall of the tube in such a manner that only a bypass flow which is a part of the gas flow within the tube passes through the dedusting unit.

Abstract: This invention relates to an excimer laser oscillation apparatus which has a laser chamber which stores a laser gas containing a gas mixture of at least one inert gas selected from the group consisting of Kr, Ar, and Ne, and F2 gas, and in which an inner surface thereof has a reflection-free surface with respect to light of a desired wavelength of 248 nm, 193 nm, or 157 nm, and the uppermost surface of the inner surface consists of a fluoride, an optical resonator which is made up of a pair of reflection mirrors arranged to sandwich the laser chamber therebetween, and in which the reflectance of the reflection mirror on the output side is 90% or more and microwave introduction means, arranged on the laser chamber, for continuously exciting the laser gas in the laser chamber.

Abstract: A molecular fluorine (F2) laser system includes a seed oscillator and power amplifier. The seed oscillator includes a laser tube including multiple electrodes therein which are connected to a discharge circuit. The laser tube is part of an optical resonator for generating a laser beam including a first line of multiple characteristic emission lines around 157 nm. The laser tube is filled with a gas mixture including molecular fluorine and a buffer gas. A low pressure seed radiation generating gas lamp is alternatively used. The gas mixture is at a pressure below that which results in the generation of a laser emission including the first line around 157 nm having a natural linewidth of less than 0.5 pm. The power amplifier amplifies the power of the beam emitted by the seed oscillator to a desired power for applications processing.

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 an ArF excimer 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: An excimer or molecular fluorine laser system includes a discharge chamber containing a gas mixture, multiple electrodes connected to a power supply circuit for energizing the gas mixture, a resonator for generating a laser beam, a processor, and means for monitoring an amplified spontaneous emission (ASE) signal of the laser, such as preferably an ASE detector. The processor receives a signal from the preferred ASE detector indicative of the ASE signal of the laser. Based on the signal from the ASE detector, the processor determines whether to initiate a responsive action for adjusting a parameter of the laser system.

Abstract: A narrow band molecular fluorine laser system includes an oscillator and an amplifier, wherein the oscillator produces a 157 nm beam having a linewidth less than 1 pm and the amplifier increases the power of the beam above a predetermined amount, such as more than one or several Watts. The oscillator includes a discharge chamber filled with a laser gas including molecular fluorine and a buffer gas, electrodes within the discharge chamber connected to a discharge circuit for energizing the molecular fluorine, and a resonator including the discharge chamber for generating a laser beam having a wavelength around 157 nm. Line-narrowing optics are included intra- and/or extra-resonator for reducing the linewidth of the laser beam to less than 1 pm. The amplifier may be the same or a different discharge chamber, and optical and/or electronic delays may be used for timing pulses from the oscillator to reach the amplifier at a maximum in the discharge current of the amplifier.

Abstract: The present invention provides an ultra pure purge system for discharge lasers. The LNP, the output coupler, the wavemeter and selected high voltage components are contained in sealed chambers each having a purge inlet port and a purge outlet port. Purge gas such as N2 is filtered and directed to each of the inlet ports. Gas exiting the outlet ports may be directed to flow monitors having alarms so that any loss of purge will be immediately detected. Purge gas may be exhausted or recirculated.

Abstract: The present invention provides a discharge-pumped excimer laser device which includes a laser chamber filled with a laser gas that is deteriorated to a small extent, magnetic bearings and a motor that are resistant to the entry of dust particles, and parts that are held in contact with the laser gas and suffer little damage, and has a long service life.

Abstract: A beam parameter monitoring unit is provided for use with a F2 laser system including means for filtering the red light from the VUV light of a beam portion split off from the mainbeam of the F2 laser before the beam portion reaches a detector. The filtering means includes a mirror that is highly reflective of VUV light (“VUV HR mirror”), particularly around 157 nm, and transparent to red light. The VUV HR mirror reflects the VUV light to a detector such that the properties and parameters of the main beam can be monitored, adjusted, controlled and/or stabilized. The VUV HR mirror is preferably surrounded by a shield for absorbing the red light transmitted through or around the VUV HR mirror. Also preferably, an aperture is provided that is just wide enough to permit the VUV radiation to substantially pass through, and to block the outer portions of the incident beam portion including substantially only red light.

Abstract: An efficient and practical means and method is provided for monitoring the F2 concentration in an F2 excimer laser. The F2 concentration is monitored by measuring the concentration F atoms and more specifically by measuring the amount of red laser light emitted during discharge. The amount of red laser light emitted during discharge is a function of the concentration of F atoms because such red laser light is emitted by excited F atoms. There is also a relationship between the concentration of F atoms and the concentration of molecular F2 in the discharge chamber. Accordingly, the concentration of F2 gas may be monitored by measuring the amount of red laser light emitted during discharge.

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 system for producing singlet delta oxygen has a source of liquid oxygen. A reactor has an input connected to the source of liquid oxygen. An optical pump is connected to an optical input of the reactor. The system can be by used as a laser by placing an optical resonator and a source of molecular iodine near the output of the reactor.

Abstract: A gas laser discharge unit is provided. The discharge unit includes an elongated electrode plate having a plurality of spaced-apart holes therein and a plurality of coaxial high voltage ducts. Each duct extends through one of the holes in the electrode plate and includes a central conductive core and an insulator element arranged around the core to electrically insulate said core from the electrode plate. An elongated high voltage electrode is electrically connected to the cores of the ducts. In addition, an elongated ground electrode is positioned to oppose the high voltage electrode and form a gas discharge gap therebetween. The ground electrode is electrically connected to the electrode plate. The gas laser discharge unit may be removably mounted as a module into a gas laser tube, such as an excimer laser tube.

Abstract: A method of minimizing contamination of optical components of a laser resonator is disclosed. The resonator components are located in an enclosure, which may contain contaminants including water vapor and organic favor released by the optical components, mounts of the optical components, or the enclosure itself. The enclosure may also contain suspended particulate matter. In order to reduce the level of these contaminants, a purging system extracts gas from the enclosure and passes the gas through a desiccant, an organic vapor trapping material, and a particulate matter filter then returns the extracted gas to the enclosure. The purging system is particularly useful for ultrafast lasers and ultraviolet lasers where the power of the laser radiation increases the probability of destabilizing reactions between laser radiation and contaminants.

Abstract: A laser component purge system for discharge lasers. The LNP, the output coupler and the wavemeter are contained in sealed chambers each having a purge inlet port and a purge outlet port. Purge gas such as N2 is directed to each of the inlet ports. A purge monitoring system is provided which monitors the purge flow and provides one or more signals to a processor which is programmed to minimize laser timeouts attributable to purge conditions without endangering the purged optical components. In a preferred embodiment, gas exiting the outlet ports are directed to flow monitors which provide the one or more signals to the processor. Purge gas may be exhausted or recirculated.

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: Method and apparatus for removing acid gases from the exhaust of lasers, which comprises adding to the effluent of the laser generator a reactive, solid, powdery material, consisting in a metal oxide or hydroxide, preferably chosen from among magnesium or calcium oxide or hydroxide, and allowing the effluent to be dispersed in the environment with the reaction products of the metal oxide with the HF/DF gases and with any unreacted amount of the metal oxide. The reactive, powdery material may be fed into laser exhaust plume formed by the laser effluent or into the primary stream which drives the exhaust gases through the ejector. The amount of metal oxides that can be used may be at least stoichiometric with respect to the HF/DF gases.

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. A parameter such as time, pulse count, driving voltage for maintaining a constant laser beam output energy, pulse shape, pulse duration, pulse stability, beam profile, bandwidth of the laser beam, temporal or spatial coherence, discharge width, or a combination thereof, which varies with a known correspondence to the partial pressure of the constituent gas is monitored. Injections of the constituent gas are performed each to increase the partial pressure by a selected amount in the discharge chamber.

Abstract: A narrow band molecular fluorine laser system includes an oscillator and an amplifier, wherein the oscillator produces a 157 nm beam having a linewidth less than 1 pm and the amplifier increases the power of the beam above a predetermined amount, such as more than one or several Watts. The oscillator includes a discharge chamber filled with a laser gas including molecular fluorine and a buffer gas, electrodes within the discharge chamber connected to a discharge circuit for energizing the molecular fluorine, and a resonator including the discharge chamber for generating a laser beam having a wavelength around 157 nm. Line-narrowing optics are included intra- and/or extra-resonator for reducing the linewidth of the laser beam to less than 1 pm. The amplifier may be the same or a different discharge chamber, and optical and/or electronic delays may be used for timing pulses from the oscillator to reach the amplifier at a maximum in the discharge current of the amplifier.

Abstract: An electrode arrangement for a gas laser is provided. The electrode arrangement includes an elongated high voltage electrode, an elongated ground electrode disposed adjacent to the high voltage electrode, a discharge gap between the two electrodes an insulator element, a high voltage conductor having a first end connected to the high voltage electrode and extending through the insulator element, and a shadow plate interposed between the discharge gap and the insulator element. The electrode arrangement may be employed in a variety of gas lasers, including excimer lasers.

Abstract: A gas discharge laser having a laser chamber with two elongated erodable electrode elements, each having an erodable section and an electrode with support configured to minimize discharge region laser gas turbulence and with the electrode elements being configured to permit gradual erosion over more than 8 billion pulses without causing substantial changes in the shape of electrical discharges between the electrode elements. A pulse power system provides electrical pulses of at least 2J at rates of at least 2 KHz. A blower circulates laser gas between the electrodes at speeds of at least 2 m/s and a heat exchanger is provided to remove heat produced by the blower and the discharges.

Abstract: An excimer laser with a laser chamber containing a circulating laser gas containing fluorine and long-life, annealed, copper alloy electrodes. Electrode lifetime is increased by annealing them after the electrodes are machined. This annealing relieves the surface stress caused by the machining operation and reduces the exposed metallic grain boundary length per unit area on the surface of the electrodes, which provides substantial reduction in erosion caused by fluorine chemical attack. Annealing after machining also reduces the stress throughout the bulk of the electrode material. In preferred embodiments the anode is a copper-aluminum alloy and the cathode is a copper-zinc alloy.

Abstract: The present invention provides an ultra pure purge system for discharge lasers. The LNP, the output coupler, the wavemeter and selected high voltage components are contained in sealed chambers each having a purge inlet port and a purge outlet port. Purge gas such as N2 is filtered and directed to each of the inlet ports. Gas exiting the outlet ports may be directed to flow monitors having alarms so that any loss of purge will be immediately detected. Purge gas may be exhausted or recirculated.

Abstract: A laser component purge system for discharge lasers. The LNP, the output coupler and the wavemeter are contained in sealed chambers each having a purge inlet port and a purge outlet port. Purge gas such as N2 is directed to each of the inlet ports. A purge monitoring system is provided which monitors the purge flow and provides one or more signals to a processor which is programmed to minimize laser timeouts attributable to purge conditions without endangering the purged optical components. In a preferred embodiment, gas exiting the outlet ports are directed to flow monitors which provide the one or more signals to the processor. Purge gas may be exhausted or recirculated.

Abstract: A laser is provided having a gain medium including a laser gas and a photoabsorbing species. The photoabsorbing species has at least one photoabsorption line within an output emission spectrum of the laser. When the laser is an ArF-excimer laser, the photoabsorbing species is preferably either atomic carbon or molecular oxygen, which are formed after carbon- or oxygen-containing molecules introduced into the gain medium with the laser gas interact within the gain medium. An absolute wavelength of a narrowed emission of the laser can be calibrated when a narrowed output emission of the laser is tuned through at least one photoabsorption line of the photo-absorbing species. Preferably, a processor communicates with a detector and a wavelength selection unit, as well as a power supply when output beam energy is held constant, to automatically perform the calibration.

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 casing for a laser device in which contaminants do not generate even if it is radiated with laser light, a production method and a cleaning method of the same are provided. For this purpose, the cleaning method is a method of cleaning a casing (19) for an ultraviolet laser device, an inside of which laser light (11) passes through, comprises the steps of purging the inside of the casing (19) with an inert gas, and radiating F2 cleaning laser light (16) oscillated from an F2 molecular laser light radiating device (15) to the inside of the casing (19) to thereby remove contaminants adhering to the inside of the casing (19).

Abstract: A long life laser chamber for a halogen containing gas discharge laser. In a preferred embodiment electrode erosion caused by excited fluorine (i.e., atomic fluorine and fluorine ions) is reduced by forcing the excited fluorine away from the discharge footprint of the electrodes. Preferred embodiments include electrodes with a large number of small holes in the discharge footprint through which laser gas flows to remove the excited fluorine from the footprint region in the time period between electric discharges.

Abstract: An F2-excimer laser has multiple closely-spaced spectral lines of interest around 157 nm, and one of the lines is selected by wavelength selection optics. The wavelength selection optics of a first preferred embodiment include a birefringent Brewster window enclosing the laser gas volume of the discharge chamber. The window preferably comprises MgF2 and is located at one end of the discharge chamber. One line is selected of the two when the optical thickness of the window is selected in coordination with rotatably adjustable, orthogonal refractive indices of the window. The transmissivity of the window is dependent on the orthogonal refractive indices and the optical thickness of the window. The wavelength selection optics of a second preferred embodiment include are at least partially within the laser active volume. In this way, line selection is performed in a manner which optimizes the combination of optical and discharge efficiency, resonator size and cost.

Abstract: This invention relates to an excimer laser oscillation apparatus which has a laser chamber which stores a laser gas containing a gas mixture of at least one inert gas selected from the group consisting of Kr, Ar, and Ne, and F2 gas, and in which an inner surface thereof has a reflection-free surface with respect to light of a desired wavelength of 248 nm, 193 nm, or 157 nm, and the uppermost surface of the inner surface consists of a fluoride, an optical resonator which is made up of a pair of reflection mirrors arranged to sandwich the laser chamber therebetween, and in which the reflectance of the reflection mirror on the output side is 90% or more and microwave introduction means, arranged on the laser chamber, for continuously exciting the laser gas in the laser chamber.

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 reliable, modular, production quality F2 excimer laser capable of producing, at repetition rates in the range of 1,000 to 2,000 Hz or greater, laser pulses with pulse energies greater than 10 mJ with a full width half, maximum bandwidth of about 1 pm or less at wavelength in the range of 157 nm. Laser gas concentrations are disclosed for reducing unwasted infrared emissions from the laser. Also disclosed are UV energy detectors which are substantially insensitive to infrared light. Preferred embodiments of the present invention can be operated in the range of 1000 to 4000 Hz with pulse energies in the range of 10 to 5 mJ with power outputs in the range of 10 to 40 watts. Using this laser as an illumination source, stepper or scanner equipment can produce integrated circuit resolution of 0.1 &mgr;m or less. Replaceable modules include a laser chamber and a modular pulse power system.

Abstract: An excimer laser system with an automatic fluorine control system to permit precise control of the fluorine concentration within an F2 “sweet spot” in a gas discharge laser chamber. This is done with a computer control system which monitors laser parameters, determines &Dgr;E/&Dgr;V, the change of pulse energy with voltage, and automatically and precisely controls the fluorine concentration based on &Dgr;E/&Dgr;V without the need to actually measure the fluorine concentration. The present invention is especially useful in lithography environments in which photo resist having a wide range of sensitivity are used. The present invention permits operation of the laser at substantially maximum efficiency over a wide range of pulse energy outputs.

Abstract: A gas laser device. The device includes a laser chamber having at least one active gas and a device for purifying gas. The purified gas is in communication with the free exchange of gas with the chamber. This device may be used with high powered gas lasers.

Abstract: In a method for determining the life of a laser light source for use with an exposure apparatus using KrF or ArF excimer laser as a light source for exposure, the method for determining the life of the laser light source is implemented by subjecting an excimer laser light source to single oscillation by blocking a pulse light, acquiring data relating to plural parameters for learning a periodical variation of the excimer laser light source and its structuring parts through an interface, and determining the life of the excimer laser light source on the basis of the data acquired. Those data is acquired on a regular basis in accompany with the work for exchanging gases at the time of exchanging gases for the excimer laser light source.