Laser-driven photon source and inspection apparatus including such a laser-driven photon source
AssigneeASML Netherlands B.V.
InventorsMartijn Petrus Christianus Van Heumen, Sergii Denega, Ralph Jozef Johannes Gerardus Anna Maria Smeets, Remco Marcel Van Dijk, Marc Van Kemenade
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Abstract
Disclosed is a laser-driven photon source comprising drive optics which focus drive radiation so as to maintain a plasma. The point spread function of the drive optics has a point spread function (75) which is configured such that a spectral position of a peak output wavelength of a black body portion of output radiation emitted by said plasma within a desired wavelength band.
Claims14
A laser-driven photon source comprising:
- drive optics configured to focus drive radiation so as to maintain a plasma,
- wherein:
- the drive optics adjusts a point spread function by adjusting one of:
- a focal length of the drive optics so as to adjust the point spread function, or
- a size of an entrance aperture of the drive optics to adjust the point spread function, and
- wherein the point spread function is configured such that a spatial intensity distribution profile of the drive radiation is a non-Gaussian distribution to reduce an energy density of the drive radiation at a focal plane of the drive optics, thereby controlling a spectral position of a peak output wavelength of a black body portion of output radiation emitted by said plasma within a desired wavelength band.
The laser-driven photon source of 1, wherein the point spread function is configured such that a focused beam diameter of the drive radiation at a focal plane of said drive optics, after having been focused by said drive optics, is greater than 100 μm, said beam diameter expressed as full width at half maximum.
Dependencies are inferred from the claim text.