| CPC G01N 23/22 (2013.01) [G03F 1/84 (2013.01)] | 5 Claims |
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1. A system of measuring an image of a pattern in a high numerical aperture (NA) scanning-type extreme ultra-violet (EUV) mask, comprising:
a coherent EUV light source generating an EUV light through a high order generation process;
an x-ray toroidal mirror focusing the EUV light on an incidence surface to have different focal lengths in a horizontal direction and a vertical direction of the incidence surface;
an x-ray flat mirror allowing light, which is reflected by the x-ray toroidal mirror, to be incident into the mask;
an x-ray beam splitter configured to reflect one portion of a beam focused by the x-ray toroidal mirror and to transmit another portion of the beam;
a light detection part detecting the reflected one portion of the beam emitted from the x-ray beam splitter;
an anamorphic zone-plate lens focusing the transmitted other portion of the beam emitted from the x-ray beam splitter on the mask, the anamorphic zone-plate lens having the same focal length and different numerical apertures (NA) in the horizontal and the vertical directions of an incidence surface;
a stage, on which a reflection-type EUV mask is placed, and which moves in a direction of an x-axis or a y-axis to scan an image of the reflection-type EUV mask; and
an anamorphic photo sensor, which is configured to measure an energy of the reflected portion of the EUV light when the EUV light is reflected by the EUV mask, comprises a detector array, and has different sizes from each other in the horizontal and the vertical directions of an incidence surface of the detector array.
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