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: 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: 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: A multi-input, multi-output vibration control system for a lithography system. The system provides an actuator, and a sensor useful for controlling vibrations in systems for fabricating electronics equipment. The system includes a processor programmed with a multi-input, multi-output control technique such as a linear quadratic Gaussian, H-infinity or mu synthesis. The actuator may comprise one or more plates or elements of electroactive material bonded to an electroded sheet.

Abstract: A long pulse power system for gas discharge lasers. The system includes a sustainer capacitor for accepting a charge from a high voltage pulse power source. A peaking capacitor with a capacitance value of less than half the sustainer capacitance provides the high voltage for the laser discharge.

Abstract: A modular actuator assembly includes one or more plates or elements of electro-active material bonded to an electroded sheet, preferably by a structural polymer to form a card. The card is sealed, and may itself constitute a practical device, such as a vane, shaker, stirrer, lever, pusher or sonicator for direct contact with a solid or immersion in a fluid, or may be bonded by a stiff adhesive to make a surface-to-surface mechanical coupling with a solid workpiece, device, substrate machine or sample. The structural polymer provides a bending stiffness such that the thin plate does not deform to its breaking point, and a mechanical stiffness such that shear forces are efficiently coupled from the plate to the workpiece. In further embodiments, the card may include active circuit elements for switching, powering or processing signals, and/or passive circuit elements for filtering, matching or damping signals, so that few or no connections to outside circuitry are required.

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: 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 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: 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: The present invention provides a wavemeter for an ultraviolet laser capable of long life beam quality monitoring in a pulsed ultraviolet laser system at pulse rates greater than 2000 Hz at pulse energies at 5 mJ or greater. In a preferred embodiment an enhanced illumination configuration reduces per pulse illumination of an etalon by a factor of 28 compared to a popular prior art configuration. Optics are provided in this embodiment which reduce light entering the etalon to only that amount needed to illuminate a linear photo diode array positioned to measure interference patterns produced by the etalon. In this preferred embodiment two sample beams produced by reflections from two surfaces of a beam splitter are diffused by a defractive diffuser and the output of the defractive diffuser is focused on two separate secondary diffusers effectively combining both beams in two separate spectrally equivalent diffuse beams.

Abstract: The present invention provides a pulse power system for extreme ultraviolet and x-ray light sources. The pulse power system produces electrical pulses of at least 12 J at pulse repetition rates of at least 2000 Hz. The system is extremely reliable and has design lifetime substantially in excess of 10 billion pulses. The system includes a charging capacitor bank, a fast charger for charging the charging capacitor bank in time periods of less than 0.5 seconds. A voltage control circuit is provided for controlling the charging voltage capacitor to within less than 0.5 percent of desired values. The system includes a magnetic compression circuit for creating, compressing in duration and amplifying voltage pulses. A trigger circuit discharges the charging capacitor bank into the pulse compression circuit so as to produce EUV or x-ray light pulses with a timing accuracy of less than 10 ns.

Abstract: A grating based line narrowing unit with bi-directional beam expansion for line narrowing lasers. In a preferred embodiment a beam from the chamber of the laser is expanded in the horizontal direction with a three-prism beam expander and is expanded in the vertical direction with a single prism. A narrow band of wavelengths in the expanded beam is reflected from a grating in a Littrow configuration back via the two beam expanders into the laser chamber for amplification.

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 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: A high resolution spectral measurement device. A preferred embodiment presents an extremely narrow slit function in the ultraviolet range and is very useful for measuring bandwidth of narrow-band excimer lasers used for integrated circuit lithography. Light from the laser is focused into a diffuser and the diffused light exiting the diffuser illuminates an etalon. A portion of its light exiting the etalon is collected and directed into a slit positioned at a fringe pattern of the etalon. Light passing through the slit is collimated and the collimated light illuminates a grating positioned in an approximately Littrow configuration which disburses the light according to wavelength. A portion of the dispursed light representing the wavelength corresponding to the selected etalon fringe is passed through a second slit and monitored by a light detector. When the etalon and the grating are tuned to the same precise wavelength a slit function is defined which is extremely narrow such as about 0.

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.

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 optical components adjustable from outside of the enclosure without the need to open it. Targets and beam directors are included within the beam path enclosure and are used to judge the quality of alignment. These target and beam directors are located on a moveable mount which is insertable in the beam path for alignment and are removed out of the beam path for normal operation. The positions of the targets and beam directors are controlled from outside the beam path enclosure. 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.

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 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.

Abstract: The present invention provides a gas discharge laser having at least one long-life elongated electrode for producing at least 12 billion high voltage electric discharges in a fluorine containing laser gas. In a preferred embodiment at least one of the electrodes is comprised of a first material having a relatively low anode erosion rate and a second anode material having a relatively higher anode erosion rate. The first anode material is positioned at a desired anode discharge region of the electrode. The second anode material is located adjacent to the first anode material along at least two long sides of the first material. During operation of the laser erosion occurs on both materials but the higher erosion rate of the second material assures that any tendency of the discharge to spread onto the second material will quickly erode away the second material enough to stop the spread of the discharge.