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: A molecular fluorine (F2) laser is provided wherein the gas mixture comprises molecular fluorine for generating a spectral emission including two or three closely spaced lines around 157 nm. An etalon provides line selection such that the output beam only includes one of these lines. The etalon may also serve to outcouple the beam and/or narrow the selected line. Alternatively, a prism provides the line selection and the etalon narrows the selected line. The etalon may be a resonator reflector which also selects a line, while another element outcouples the beam. The etalon plates comprise a material that is substantially transparent at 157 nm, such as CaF2, MgF2, LiF2, BaF2, LiF, SrF2, quartz and fluorine doped quartz. The etalon plates are separated by spacers comprising a material having a low thermal expansion constant, such as invar, zerodur®, ultra low expansion glass, and quartz.

Abstract: An excimer or molecular fluorine laser includes a gain medium surrounded by a resonator and including a line-narrowing module preferably including a prism beam expander and one or more etalons and/or a grating or grism within the resonator. The material of transmissive portions of the line-narrowing module including the prisms and the plates of the etalons comprises a material having an absorption coefficient of less than 5×1031 3/cm at 248 nm incident radiation, less than 10×10−3/cm at 193 nm incident radiation, and less than 0.1/cm at 157 nm. Preferably the material also has a thermal conductivity greater than 2.0 W/m° C.

Abstract: A laser for an excimer or molecular fluorine laser includes an electrode chamber connected with a gas flow vessel and having a pair of main electrodes and a preionization unit each connected to a discharge circuit. A spoiler is provided within the electrode chamber and is shaped to provide a more uniform gas flow through the discharge area between the main electrodes, to shield one of the preionization units from one of the main electrodes, and to reflect acoustic waves generated in the discharge area into the gas flow vessel for absorption therein. A spoiler unit may include a pair of opposed spoiler elements on either side of the discharge area. One or both main electrodes includes a base portion and a center portion which may be a nipple protruding from the base portion. The center portion substantially carries the periodic discharge current such that the discharge width is and may be significantly less than the width of the base portion.

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 excimer or molecular fluorine laser includes a gain medium surrounded by a resonator and including a line-narrowing module preferably including a prism beam expander and one or more etalons and/or a grating or grism within the resonator. The material of transmissive portions of the line-narrowing module including the prisms and the plates of the etalons comprises a material having an absorption coefficient of less than 5×10−3/cm at 248 nm incident radiation, less than 10×10−3/cm at 193 nm incident radiation, and less than 0.1/cm at 157 nm. Preferably the material also has a thermal conductivity greater than 2.0 W/m° C.

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 molecular fluorine (F2) laser is provided wherein the gas mixture includes molecular fluorine for generating an emission spectrum including two or three closely spaced lines around 157 nm. An optical method and means are provided for selecting an emission line from among the plurality of closely spaced emission lines of the molecular fluorine laser gas volume and broadening the spectrum of said selected emission line. This approach of broadening the spectrum reduces the coherence length of the output beam. As a result, speckle may be reduced or avoided in microlithography applications.

Abstract: An ultraviolet light detection system is provided wherein a dark current background growth rate with total accumulated exposure dose is avoided, and parameters of an ultraviolet radiation source such as an ArF-excimer laser may be monitored without rapid degradation of the signal by the superposition of the dark current background over a desired signal. The invention provides a detector including a light sensitive element having a frequency conversion coating on its surface. The coating is preferably directly on the light sensitive element, absorbing incident ultraviolet light and re-emitting visible light in a direction toward the light sensitive element. The coating minimizes a dark current background that would otherwise appear when incident ultraviolet light impinges directly upon the light sensitive element, and thereby extends a lifetime of the light sensitive element.

Abstract: A method and apparatus are provided for temporally stretching and smoothing of the pulses of an output beam of excimer and lithography lasers. The method and apparatus are based upon providing an optical delay line or circuit having a plurality of optical reflectors and a plurality of beam recombiners or splitters so arranged as to divide the pulse into numerous portions which vary in their travel time through the circuit. As a result, the energy of the incident pulse is greatly stretched and smoothed.

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: A F2-laser includes a discharge chamber filled with a gas mixture including molecular fluorine for generating a spectral emission in a wavelength range between 157 nm and 158 nm including a primary line and a secondary line, multiple electrodes coupled with a power supply circuit for producing a pulsed discharge to energize the molecular fluorine, a resonator including the discharge chamber and an interferometric device for generating a laser beam having a bandwidth of less than 1 pm, and a wavelength monitor coupled in a feedback loop with a processor for monitoring a spectral distribution of the laser beam. The processor controls an interferometric spectrum of the interferometric device based on the monitored spectral distribution such that sidebands within the spectral distribution are substantially minimized.

Abstract: Method and system for providing an excimer or molecular fluorine laser including a laser tube filled with a laser gas surrounded by an optical resonator, where the laser tube has multiple electrodes including a pair of main discharge electrodes connected to a discharge circuit for exciting the laser gas to produce a laser output beam. The discharge circuit has an all solid state switch and preferably does not include a transformer. The solid state switch includes multiple solid state devices that may be capable of switching voltages in excess of 12 kV, such as 14-32 kV or more, or the voltage needed to switch the laser. The series of switches has a rise time of approximately less than 300 ns, and preferably around 100 ns or less. The switch may be capable of switching voltages of slightly more than half, but less than the entire voltage needed to produce laser pulses of desired energies, and a voltage doubling circuit may be used to produce the voltage required to produce the desired output pulse energies.

Abstract: A line-narrowing module for a laser includes a prism beam expander and a grating preferably attached to a heat sink. A pressure-controlled enclosure filled with an inert gas seals the grating and/or other elements of the line-narrowing module. The pressure in the enclosure is adjusted for tuning the wavelength. Preferably, the pressure is controlled by controlling the flow of an inert gas through the enclosure. A pump may be used, or an overpressure flow may be used. Alternatively, a prism of the beam expander or an etalon may be rotatable for tuning the wavelength.

Abstract: A wavelength calibration system determines an absolute wavelength of a narrowed spectral emission band of an excimer or molecular laser system. The system includes a module including an element which optically interacts with a component of an output beam of the laser within the tunable range of the laser system around the narrowed band. An inter-level resonance is detected by monitoring changes in voltage within the module, or photo-absorption is detected by photodetecting equipment. The absolute wavelength of the narrowed band is precisely determinable when the optical transitions occur and are detected. When the system specifically includes an ArF-excimer laser chamber, the module is preferably a galvatron containing an element that photo-absorbs around 193 nm and the element is preferably a gas or vapor selected from the group consisting of arsenic, carbon, oxygen, iron, gaseous hydrocarbons, halogenized hydrocarbons, carbon-contaminated inert gases, germanium and platinum vapor.

Abstract: An excimer or molecular fluorine laser system includes a laser tube filled with a gas mixture including fluorine and a buffer gas, and multiple electrodes within the laser tube connected with a pulsed discharge circuit for energizing the gas mixture. At least one of the electrodes is longer than 28 inches in length, preferably two main electrodes are each extended to greater than 28 inches in length. The laser system further includes a resonator including the laser tube for generating a pulsed laser beam having a desired energy. The laser system is configured such that an output beam would be emitted having an energy below the desired energy if each of the electrodes were 28 inches in length or less, and the laser system outputs a beam at the desired energy due to the length of the electrodes being extended to a length greater than 28 inches.

Abstract: A laser for an excimer or molecular fluorine laser includes an electrode chamber connected with a gas flow vessel and having a pair of main electrodes and a preionization unit each connected to a discharge circuit. A spoiler is provided within the electrode chamber and is shaped to provide a more uniform gas flow through the discharge area between the main electrodes, to shield one of the preionization units from one of the main electrodes, and to reflect acoustic waves generated in the discharge area into the gas flow vessel for absorption therein. A spoiler unit may include a pair of opposed spoiler elements on either side of the discharge area. One or both main electrodes includes a base portion and a center portion which may be a nipple protruding from the base portion. The center portion substantially carries the periodic discharge current such that the discharge width is and may be significantly less than the width of the base portion.

Abstract: An ultraviolet light detection system is provided wherein a dark current background growth rate with total accumulated exposure dose is avoided, and parameters of an ultraviolet radiation source such as an ArF-excimer laser may be monitored without rapid degradation of the signal by the superposition of the dark current background over a desired signal. The invention provides a detector including a light sensitive element having a frequency conversion coating on its surface. The coating is preferably directly on the light sensitive element, absorbing incident ultraviolet light and re-emitting visible light in a direction toward the light sensitive element. The coating minimizes a dark current background that would otherwise appear when incident ultraviolet light impinges directly upon the light sensitive element, and thereby extends a lifetime of the light sensitive element.

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: An ultraviolet light detection system is provided wherein a dark current background growth rate with total accumulated exposure dose is avoided, and parameters of an ultraviolet radiation source such as an ArF-excimer laser may be monitored without rapid degradation of the signal by the superposition of the dark current background over a desired signal. The invention provides a detector including a light sensitive element having a frequency conversion coating on its surface. The coating is preferably directly on the light sensitive element, absorbing incident ultraviolet light and re-emitting visible light in a direction toward the light sensitive element. The coating minimizes a dark current background that would otherwise appear when incident ultraviolet light impinges directly upon the light sensitive element, and thereby extends a lifetime of the light sensitive element.