摘要:
An oscillator-amplifier gas discharge laser system and method is disclosed which may comprise a first laser unit which may comprise a first discharge region which may contain an excimer or molecular fluorine lasing gas medium; a first pair of electrodes defining the first discharge region containing the lasing gas medium, a line narrowing unit for narrowing a spectral bandwidth of output laser light pulse beam pulses produced in said first discharge region; a second laser unit which may comprise a second discharge chamber which may contain an excimer or molecular fluorine lasing gas medium; a second pair of electrodes defining the second discharge region containing the lasing gas medium; a pulse power system providing electrical pulses to the first pair of electrodes and to the second pair of electrodes producing gas discharges in the lasing gas medium between the respective first and second pair of electrodes, and laser parameter control mechanism modifying a selected parameter of a selected laser output light pulse beam pulse produced by said gas discharge laser system by controlling the timing of the occurrence of the gas discharge between the first pair of electrodes and the occurrence of the gas discharge between the second pair of electrodes.
摘要:
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. The master oscillator is equipped with a line narrowing package having a very fast tuning mirror capable of controlling centerline wavelength on a pulse-to-pulse basis at repetition rates of 4000 Hz or greater to a precision of less than 0.2 pm.
摘要:
A high resolution etalon-grating monochromator. 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 0.034 pm (FWHM) and about 0.091 pm (95 percent integral). The bandwidth of a laser beam can be measured very accurately by a directing portion of the laser beam into the monochromator and scanning the laser wavelength over a range which includes the monochromator slit wavelength.
摘要:
A bidirectional bandwidth controlled grating assembly. A spring housing is connected to one of two end plates extending away from the lined surface of the grating. An adjustment rod threaded through the other end plate extends into the spring housing. Inside the spring housing in a preferred embodiment are two compression springs mounted between pressure surfaces in the housing and a piston which is fixed on the adjustment rod. The lined surface of the grating can be made more concave (or less convex) by screwing the rod in a direction into the spring housing compressing one of the springs to push the end plates apart and the surface can be made more convex (or less concave) by screwing the rod in a direction out of the spring housing compressing the other spring to pull the end plates toward each other.
摘要:
A reliable, modular, production quality narrow-band KrF excimer laser capable of producing 10 mJ laser pulses at 1000 Hz with a bandwidth of about 0.6 pm or less. The present invention is especially suited to long-term round-the-clock operation in the lithographic production of integrated circuits. Improvements over prior art lasers include a single upstream preionizer tube and acoustic baffles. A preferred embodiment includes reduced fluorine concentration, an anode support bar shaped to reduce aerodynamic reaction forces on blower bearings, a modified pulse power system providing faster pulse rise time, an output coupler with substantially increased reflectivity, a line narrowing module with CaF prism beam expanders, a more accurate wavemeter, a laser computer controller programmed with new and improved pulse energy control algorithm.
摘要:
A method and apparatus may comprise a line narrowed pulsed excimer or molecular fluorine gas discharge laser system which may comprise a seed laser oscillator producing an output comprising a laser output light beam of pulses which may comprise a first gas discharge excimer or molecular fluorine laser chamber; a line narrowing module within a first oscillator cavity; a laser amplification stage containing an amplifying gain medium in a second gas discharge excimer or molecular fluorine laser chamber receiving the output of the seed laser oscillator and amplifying the output of the seed laser oscillator to form a laser system output comprising a laser output light beam of pulses, which may comprise a ring power amplification stage.
摘要:
A device comprising a laser source producing a continuous output on a beam path and an amplifier is disclosed. The device further includes a partially transmissive, partially reflective optic disposed on said beam path between said laser source and said amplifier. The device further includes a droplet generator positioned to deliver a droplet moving on a path intersecting said beam path, the droplet reflecting light to establish an optical cavity with said optic.
摘要:
Devices and corresponding methods of use are described herein that may include an enclosing structure defining a closed loop flow path and a system generating a plasma at a plasma site, e.g. laser produced plasma system, where the plasma site may be in fluid communication with the flow path. For the device, a gas may be disposed in the enclosing structure which may include an ion-stopping buffer gas and/or an etchant. A pump may be provided to force the gas through the closed loop flow path. One or more heat exchangers removing heat from gas flowing in the flow path may be provided. In some arrangements, a filter may be used to remove at least a portion of a target species from gas flowing in the flow path.
摘要:
A method and apparatus may comprise a line narrowed pulsed excimer or molecular fluorine gas discharge laser system which may comprise a seed laser oscillator producing an output comprising a laser output light beam of pulses which may comprise a first gas discharge excimer or molecular fluorine laser chamber; a line narrowing module within a first oscillator cavity; a laser amplification stage containing an amplifying gain medium in a second gas discharge excimer or molecular fluorine laser chamber receiving the output of the seed laser oscillator and amplifying the output of the seed laser oscillator to form a laser system output comprising a laser output light beam of pulses, which may comprise a ring power amplification stage.
摘要:
Devices are disclosed herein which may comprise an EUV reflective optic having a surface of revolution that defines a rotation axis and a circular periphery. The optic may be positioned to incline the axis at a nonzero angle relative to a horizontal plane, and to establish a vertical projection of the periphery in the horizontal plane with the periphery projection bounding a region in the horizontal plane. The device may further comprise a system delivering target material, the system having a target material release point that is located in the horizontal plane and outside the region, bounded by the periphery projection and a system generating a laser beam for irradiating the target material to generate an EUV emission.