Sensor for use in a lithographic apparatus
AssigneeASML Netherlands B.V.
InventorsHaico Victor Kok, Marcus Adrianus Van De Kerhof, Borgert Kruizinga, Timotheus Franciscus Sengers, Bearrach Moest, Marc Antonius Maria Haast, Peter Weissbrodt, Manfred Schrenk, Torsten Harzendorf
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Abstract
A sensor for use at substrate level in a high numerical aperature lithographic apparatus, the sensor having a transparent plate that covers a sensing element and includes elements that improve coupling of radiation into the sensing element. The elements include Fresnel lenses, holographic optical elements, inverted Winston Cones, spherical lenses and surface roughening.
Claims3
A sensor for use at a substrate level in a lithographic projection apparatus having a projection system with a numeric aperture that is greater than 1 that is configured to project a patterned radiation beam onto a target portion of a substrate, the sensor comprising:
- a radiation-detector;
- a transmissive plate having a front surface and a back surface, the transmissive plate being positioned such that radiation projected by the projection system passes into the front surface of the transmissive plate and out of the back surface thereof to the radiation detector;
- and
- a Fresnel lens provided on the back surface of the transmissive plate and arranged to couple radiation to the radiation detector.
Dependencies are inferred from the claim text.