摘要:
A line narrowing apparatus and method for a narrow band DUV high power high repetition rate gas discharge laser producing output laser light pulse beam pulses in bursts of pulses is disclosed, which may comprise a dispersive center wavelength selection optic contained within a line narrowing module, selecting at least one center wavelength for each pulse determined at least in part by the angle of incidence of the laser light pulse beam containing the respective pulse on a dispersive wavelength selection optic dispersive surface; a first dispersive optic bending mechanism operatively connected to the dispersive center wavelength selection optic and operative to change the curvature of the dispersive surface in a first manner; and, a second dispersive optic bending mechanism operatively connected to the dispersive center wavelength selection optic and operative to change the curvature of the dispersive surface in a second manner. The first manner may modify a first measure of bandwidth and the second manner may modify a second measure of bandwidth such that the ratio of the first measure to the second measure substantially changes. The first measure may be a spectrum width at a selected percentage of the spectrum peak value (FWX % M) and the second measure may be width within which some selected percentage of the spectral intensity is contained (EX %). The first dispersive optic bending mechanism may change the curvature of the dispersive surface in a first dimension and the second in a second dimension generally orthogonal to the first dimension. The laser system may comprise a beam path insert comprising a material having an different index of refraction and an index of refraction thermal gradient opposite from that of a neighboring optical element. The first dispersive optic bending mechanism may change the curvature of the dispersive surface in a first dimension and the second a second dimension generally parallel to the first dimension. An optical beam twisting element in the lasing cavity may optically twist the laser light pulse beam to present a twisted wavefront to the dispersive center wavelength selection optic. Bending may change the curvature and wavelength selection, e.g., in a burst may create two center wavelength peaks to select FWX % M and EX % independently.
摘要:
A line narrowing method and module for a narrow band DUV high power high repetition rate gas discharge laser producing output laser light pulse beam pulses in bursts of pulses, the module having a nominal optical path are disclosed which may comprise: a dispersive center wavelength selection optic moveably mounted within an optical path of the line narrowing module, selecting at least one center wavelength for each pulse determined at least in part by the angle of incidence of the laser light pulse beam containing the respective pulse on the dispersive wavelength selection optic; a first tuning mechanism operative in part to select the angle of incidence of the laser light pulse beam containing the respective pulse upon the dispersive center wavelength selection optic, by selecting an angle of transmission of the laser light pulse beam containing the pulse toward the dispersive center wavelength selection optic; a second tuning mechanism operative in part to select the angle of incidence of the laser light pulse beam containing the respective pulse by changing the position of the dispersive center wavelength selection optic relative to the nominal optical path of the line narrowing module; wherein the second tuning mechanism coarsely selects a value for the center wavelength and the first tuning mechanism more finely selects the value for the center wavelength. The apparatus and method may further comprise at least one beam expanding and redirecting prism in the optical path of the line narrowing module; the first tuning mechanism selecting an angle of incidence of the at least a first spatially defined portion of the laser light pulse beam by changing the position of the at least one beam expanding prism relative to the nominal optical path of the line narrowing module. The first and second tuning mechanisms may be controlled by a center wavelength controller during a burst based upon feedback from a center wavelength detector detecting the center wavelength of at least one other pulse in the burst of pulses and the controller providing the feedback based upon an algorithm employing the detected center wavelength for the at least one other pulse in the burst. The first tuning mechanism may comprise an electro-mechanical course positioning mechanism and a fine positioning mechanism comprising an actuatable material that changes position or shape when actuated.
摘要:
A line narrowed gas discharge laser system and method of operation are disclosed which may comprise: an oscillator cavity; a laser chamber comprising a chamber housing containing a lasing medium gas; at least one peaking capacitor electrically connected to the chamber housing and to a first one of a pair of electrodes; a second one of the pair of electrodes connected to an opposite terminal of the at least one peaking capacitor; a current return path connected to the chamber housing; the one terminal, the first one of the electrodes, the lasing medium gas, the second one of the electrodes, the current return path and the second terminal forming a head current inductive loop having an inductance unique to the particular head current inductive loo; a spectral quality tuning mechanism comprising a mechanism for changing the particular head current inductive loop inductance value for the particular head current inductance loop.
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 apparatus and method are disclosed for operating a narrow band short pulse duration gas discharge laser output light pulse beam producing system, producing a beam comprising laser output light pulses at a selected pulse repetition rate, which may comprise: a dispersive center wavelength selection optic selecting at least one center wavelength for each pulse determined at least in part by the angle of incidence of the laser light pulse beam containing the respective pulse on the dispersive wavelength selection optic; a tuning mechanism operative to select at least one angle of incidence of a first spatially defined portion of the laser light pulse beam containing the respective pulse upon the dispersive center wavelength selection optic; and, the tuning mechanism comprising a variably refractive optical element defining a plurality of refractive angular displacements of the first spatially defined portion of the laser light pulse beam passing through the variably refractive optical element at one of a plurality of positions of incidence of the laser light pulse beam on the variably refractive optical element. The variably refractive optical element may comprise: a first generally flat face defining a surface of incidence for the laser light pulse beam; and, a second multifaceted or curved face defining a plurality of generally flat surfaces of exit or a continuously varying surface of exit for the laser light beam. Other aspects of pulse parameter metrology and pulse modulation control, including in response to signals from the utilization tool are disclosed, e.g., relating to proper dose control with differing center wavelength spectra.
摘要:
An apparatus and method for providing bandwidth control in a narrow band short pulse duration gas discharge laser output light pulse beam producing system, producing a beam comprising laser output light pulses at a selected pulse repetition rate, is disclosed which may comprise a dispersive bandwidth selection optic selecting at least one center wavelength for each pulse determined at least in part by the angle of incidence of the laser light pulse beam containing the respective pulse on the dispersive wavelength selection optic; a tuning mechanism operative to select at least one angle of incidence of the a laser light pulse beam containing the respective pulse upon the dispersive center wavelength selection optic; the tuning mechanism comprising a plurality of incidence angle selection elements each defining an angle of incidence for a different spatially separated but not temporally separated portion of the laser light pulse to return from the dispersive center wavelength selection optic a laser light pulse comprising a plurality of spatially separated but not temporally separated portions, each portion having one of at least two different selected center wavelengths. The tuning mechanism may comprise a temporal angle of incidence selection element defining an angle of incidence for different temporally separated portions of the pulse to return from the dispersive bandwidth selection optic a laser beam comprising a plurality of temporally separated portions of each pulse, each temporally separated portion of each pulse having one of at least two different selected center wavelengths. The tuning mechanism may comprise a plurality of spatial incidence angle selection elements each defining an angle of incidence for a spatially separated but not temporally separated portion of the laser light pulse, and a plurality of temporal angle of incidence selection elements each defining at least a first angle of incidence for at least a first temporally separated portion of each spatially separated but not temporally separated portion of the pulse and a second angle of incidence for a second temporally separated but not spatially separated portion of each spatially separated portion of the pulse.
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:
A method and apparatus if disclosed which may comprise a high power high repetition rate gas discharge laser UV light source which may comprise: a gas discharge chamber comprising an interior wall comprising a vertical wall and an adjacent bottom wall; a gas circulation fan creating a gas flow path adjacent the interior vertical wall and the adjacent bottom wall; an in-chamber dust trap positioned a region of low gas flow, which may be along an interior wall and may comprise at least one meshed screen, e.g., a plurality of meshed screens, which may comprise at least two different gauge meshed screens. The dust trap may extend along the bottom interior wall of the chamber and/or a vertical portion of the interior wall. The dust trap may comprise a first meshed screen having a first gauge; a second meshed screen having a second gauge smaller than the first gauge; and the second meshed screen intermediate the first meshed screen and the interior wall. The chamber may comprise a plurality of dust collecting recesses in at least one of the vertical interior wall and the bottom wall of the chamber which may be selected from a group comprising a one-part recess and a multi-part recess, which may comprise two sections angled with respect to each other. The dust trap may comprise a pressure trap positioned between a portion of a main insulator and an interior wall of the chamber. The chamber may comprise a gas circulating fan comprising a cross-flow fan with a fan cutoff that may comprise a vortex control pocket. The chamber may comprise a preionization mechanism comprising a preionization tub containing a ground rod within an elongated opening in the preionization tube that may comprise a compliant member, an automatic preionization shut-off mechanism, a preionization onset control mechanism and/or a focusing element. The chamber may comprise an elongated baffle plate that may comprise a plurality of pyramidal structures including varying numbers of generally pyramidal elements and oriented in groups of varying numbers of generally pyramidal elements and oriented along and transverse to the longitudinal axis. Acoustic resonances within the chamber may also be reduced by introducing an artificial jitter into the timing of the laser discharges varying the inter-pulse period randomly or in a repeating pattern from pulse to pulse within a burst.
摘要:
A line narrowed gas discharge laser system and method of operating same is disclosed which may comprise a dispersive center wavelength selective element; a beam expander comprising a plurality of refractive elements; a refractive element positioning mechanism positioning at least one of the refractive elements to modify an angle of incidence of a laser light beam on the dispersive center wavelength selection element; each of the dispersive center wavelength selection element and the beam expander being aligned with each other and with a housing containing at least the dispersive center wavelength selection element; a housing positioning mechanism positioning the housing with respect to an optical axis of the gas discharge laser system. The dispersive element may comprise a grating and the beam expander may comprise a plurality of prisms. The housing may contain the dispersive center wavelength selective element and the beam expander. The housing positioning element may comprise a position locking mechanism.
摘要:
A method and apparatus that may comprise an EUV light producing mechanism utilizing an EUV plasma source material comprising a material that will form an etching compound, which plasma source material produces EUV light in a band around a selected center wavelength comprising: an EUV plasma generation chamber; an EUV light collector contained within the chamber having a reflective surface containing at least one layer comprising a material that does not form an etching compound and/or forms a compound layer that does not significantly reduce the reflectivity of the reflective surface in the band; an etchant source gas contained within the chamber comprising an etchant source material with which the plasma source material forms an etching compound, which etching compound has a vapor pressure that will allow etching of the etching compound from the reflective surface. The etchant source material may comprises a halogen or halogen compound. The etchant source material may be selected based upon the etching being stimulated in the presence of photons of EUV light and/or DUV light and/or any excited energetic photons with sufficient energy to stimulate the etching of the plasma source material. The apparatus may further comprise an etching stimulation plasma generator providing an etching stimulation plasma in the working vicinity of the reflective surface; and the etchant source material may be selected based upon the etching being stimulated by an etching stimulation plasma. There may also be an ion accelerator accelerating ions toward the reflective surface. The ions may comprise etchant source material. The apparatus and method may comprise a part of an EUV production subsystem with an optical element to be etched of plasma source material.