摘要:
A method and apparatus for debris removal from a reflecting surface of an EUV collector in an EUV light source is disclosed which may comprise the reflecting surface comprises a first material and the debris comprises a second material and/or compounds of the second material, the system and method may comprise a controlled sputtering ion source which may comprise a gas comprising the atoms of the sputtering ion material; and a stimulating mechanism exciting the atoms of the sputtering ion material into an ionized state, the ionized state being selected to have a distribution around a selected energy peak that has a high probability of sputtering the second material and a very low probability of sputtering the first material. The stimulating mechanism may comprise an RF or microwave induction mechanism.
摘要:
The present invention provides a reliable, high-repetition rate, production line compatible high energy photon source. A very hot plasma containing an active material is produced in vacuum chamber. The active material is an atomic element having an emission line within a desired extreme ultraviolet (EUV) range. A pulse power source comprising a charging capacitor and a magnetic compression circuit comprising a pulse transformer, provides electrical pulses having sufficient energy and electrical potential sufficient to produce the EUV light at an intermediate focus at rates in excess of 5 Watts. In preferred embodiments designed by Applicants in-band, EUV light energy at the intermediate focus is 45 Watts extendable to 105.8 Watts.
摘要:
An DPP EUV source is disclosed which may comprise a debris mitigation apparatus employing a metal halogen gas producing a metal halide from debris exiting the plasma. The EUV source may have a debris shield that may comprise a plurality of curvilinear shield members having inner and outer surfaces connected by light passages aligned to a focal point, which shield members may be alternated with open spaces between them and may have surfaces that form a circle in one axis of rotation and an ellipse in another. The electrodes may be supplied with a discharge pulse shaped to produce a modest current during the axial run out phase of the discharge and a peak occurring during the radial compression phase of the discharge. The light source may comprise a turbomolecular pump having an inlet connected to the generation chamber and operable to preferentially pump more of the source gas than the buffer gas from the chamber. The source may comprise a tuned electrically conductive electrode comprising: a differentially doped ceramic material doped in a first region to at least select electrical conductivity and in a second region at least to select thermal conductivity. The first region may be at or near the outer surface of the electrode structure and the ceramic material may be SiC or alumina and the dopant is BN or a metal oxide, including SiO or TiO2. The source may comprise a moveable electrode assembly mount operative to move the electrode assembly mount from a replacement position to an operating position, with the moveable mount on a bellows. The source may have a temperature control mechanism operatively connected to the collector and operative to regulate the temperature of the respective shell members to maintain a temperature related geometry optimizing the glancing angle of incidence reflections from the respective shell members, or a mechanical positioner to position the shell members. The shells may be biased with a voltage. The debris shield may be fabricated using off focus laser radiation. The anode may be cooled with a hollow interior defining two coolant passages or porous metal defining the passages. The debris shield may be formed of pluralities of large, intermediate and small fins attached either to a mounting ring or hub or to each other with interlocking tabs that provide uniform separation and strengthening and do not block any significant amount of light.
摘要:
The present invention provides a reliable, high-repetition rate, production line compatible high energy photon source. A very hot plasma containing an active material is produced in vacuum chamber. The active material is an atomic element having an emission line within a desired extreme ultraviolet (EUV) range. A pulse power source comprising a charging capacitor and a magnetic compression circuit comprising a pulse transformer, provides electrical pulses having sufficient energy and electrical potential sufficient to produce the EUV light at an intermediate focus at rates in excess of 5 Watts. In preferred embodiments designed by Applicants in-band, EUV light energy at the intermediate focus is 45 Watts extendable to 105.8 Watts.
摘要:
An apparatus and method for EUV light production is disclosed which may comprise a laser produced plasma (“LPP”) extreme ultraviolet (“EUV”) light source control system comprising a target delivery system adapted to deliver moving plasma initiation targets and an EUV light collection optic having a focus defining a desired plasma initiation site, comprising: a target tracking and feedback system comprising: at least one imaging device providing as an output an image of a target stream track, wherein the target stream track results from the imaging speed of the camera being too slow to image individual plasma formation targets forming the target stream imaged as the target stream track; a stream track error detector detecting an error in the position of the target stream track in at least one axis generally perpendicular to the target stream track from a desired stream track intersecting the desired plasma initiation site. At least one target crossing detector may be aimed at the target track and detecting the passage of a plasma formation target through a selected point in the target track. A drive laser triggering mechanism utilizing an output of the target crossing detector to determine the timing of a drive laser trigger in order for a drive laser output pulse to intersect the plasma initiation target at a selected plasma initiation site along the target track at generally its closest approach to the desired plasma initiation site. A plasma initiation detector may be aimed at the target track and detecting the location along the target track of a plasma initiation site for a respective target. An intermediate focus illuminator may illuminate an aperture formed at the intermediate focus to image the aperture in the at least one imaging device. The at least one imaging device may be at least two imaging devices each providing an error signal related to the separation of the target track from the vertical centerline axis of the image of the intermediate focus based upon an analysis of the image in the respective one of the at least two imaging devices. A target delivery feedback and control system may comprise a target delivery unit; a target delivery displacement control mechanism displacing the target delivery mechanism at least in an axis corresponding to a first displacement error signal derived from the analysis of the image in the first imaging device and at least in an axis corresponding to a second displacement error signal derived from the analysis of the image in the second imaging device.
摘要:
Systems and methods are disclosed for reducing the influence of plasma generated debris on internal components of an EUV light source. In one aspect, an EUV metrology monitor is provided which may have a heater to heat an internal multi-layer filtering mirror to a temperature sufficient to remove deposited debris from the mirror. In another aspect, a device is disclosed for removing plasma generated debris from an EUV light source collector mirror having a different debris deposition rate at different zones on the collector mirror. In a particular aspect, an EUV collector mirror system may comprise a source of hydrogen to combine with Li debris to create LiH on a collector surface; and a sputtering system to sputter LiH from the collector surface. In another aspect, an apparatus for etching debris from a surface of a EUV light source collector mirror with a controlled plasma etch rate is disclosed.
摘要:
An apparatus and method is described for effectively and efficiently providing plasma irradiation laser light pulses in an LPP EUV light source which may comprise a laser initial target irradiation pulse generating mechanism irradiating a plasma initiation target with an initial target irradiation pulse to form an EUV generating plasma having an emission region emitting in-band EUV light; a laser plasma irradiation pulse generating mechanism irradiating the plasma with a plasma irradiation pulse after the initial target irradiation pulse so as to compress emission material in the plasma toward the emission region of the plasma. The plasma irradiation pulse may comprise a laser pulse having a wavelength that is sufficiently longer than a wavelength of the initial target irradiation pulse to have an associated lower critical density resulting in absorption occurring within the plasma in a region of the plasma defined by the wavelength of the plasma irradiation pulse sufficiently separated from an initial target irradiation site to achieve compression of the emission material, and the may compress the emission region. The laser plasma irradiation pulse may produce an aerial mass density in the ablating cloud of the plasma sufficient to confine the favorably emitting plasma for increased conversion efficiency. The deposition region for the plasma irradiation pulse may be is removed enough from the initial target surface so as to insure compression of the favorably emitting plasma. A high conversion efficiency laser produced plasma extreme ultraviolet (“EUV”) light source may comprise a laser initial target irradiation pulse generating mechanism irradiating a plasma initiation target with a target irradiation pulse to form an EUV generating plasma emitting in-band EUV light; a plasma tamper substantially surrounding the plasma to constrain the expansion of the plasma.
摘要:
A device is disclosed which may comprise a system generating a plasma at a plasma site, the plasma producing EUV radiation and ions exiting the plasma. The device may also include an optic, e.g., a multi-layer mirror, distanced from the site by a distance, d, and a flowing gas disposed between the plasma and optic, the gas establishing a gas pressure sufficient to operate over the distance, d, to reduce ion energy below a pre-selected value before the ions reach the optic. In one embodiment, the gas may comprise hydrogen and in a particular embodiment, the gas may comprise greater than 50 percent hydrogen by volume.
摘要:
It will be understood that an apparatus and method is disclosed, which may comprise a multi-layer reflecting coating forming an EUV reflective surface which may comprise a spectral filter tuned to selectively highly reflect light in a band centered about at a first preferred wavelength and to significantly reduce the reflection of light at a band centered about a second wavelength, e.g., it may be tuned to reflect maximally or almost maximally, near the top of the reflectivity curve, e.g., at around 13.5 nm and at a significantly lower reflectivity at, e.g., around 11 nm, to discriminate against light near 11 nm and favor light at around 13.5 nm. The spectral filter may comprise a plurality of nested grazing angle of incidence shells comprising reflective surfaces comprising the multi-layer reflective coating. e.g. multilayer mirrors, e.g., with one or more reflecting surfaces per shell.
摘要:
An apparatus and method is described which may comprise a plasma produced extreme ultraviolet (“EUV”) light source multilayer collector which may comprise a plasma formation chamber; a shell within the plasma formation chamber in the form of a collector shape having a focus; the shell having a sufficient size and thermal mass to carry operating heat away from the multilayer reflector and to radiate the heat from the surface of the shell on a side of the shell opposite from the focus. The material of the shell may comprise a material selected from a group which may comprise silicon carbide, silicon, Zerodur or ULE glass, aluminum, beryllium, molybdenum, copper and nickel. The apparatus and method may comprise at least one radiative heater directed at the shell to maintain the steady state temperature of the shell within a selected range of operating temperatures.